JP4866183B2 - Sheet conveying apparatus, image reading apparatus, and image forming apparatus - Google Patents

Description

  The present invention relates to a sheet conveying apparatus, a copier equipped with the sheet conveying apparatus, a facsimile, a printer, a printing machine, an inkjet recording apparatus, an image reading apparatus such as a scanner, or a combination machine combining at least two of them. The present invention relates to an image forming apparatus.

  Conventionally, image forming apparatuses such as copiers, facsimiles, printers, printers, ink jet recording apparatuses, etc., including PPC (plain paper copier: plain paper copiers), etc., are designed to reduce the size of the entire apparatus. For transporting and supplying an image forming medium or a sheet-like recording medium (hereinafter referred to as “sheet”), which is a medium on which the image is formed, from the sheet storage unit or the sheet stacking unit for stacking sheets to the image forming unit main body The conveying means also tends to be downsized. Hereinafter, the sheet storing means for storing the sheet will be described as a representative.

  Further, the image forming apparatus generally has a model corresponding to various sheet sizes (hereinafter referred to as “paper size”) and sheet types (hereinafter referred to as “paper type”). In such an image forming apparatus model, for example, a sheet (hereinafter, referred to as “paper” illustratively) having several paper sizes and types is stored in advance in a sheet storage unit, and the user selects as appropriate. The sheet can be fed from the sheet storing means or the sheet automatically selected by the image forming apparatus. Accordingly, in the case of such a configuration, the sheet storage unit occupies more space in the image forming apparatus and consumes it, so that the demand for downsizing the transport unit is increased.

For these reasons, the conveyance path formed between the sheet storage unit and the image forming unit main body in the image forming apparatus depends on the positional relationship between the two. The space occupied is reduced. As a result, a curved portion having a curved shape is provided on the conveyance path in order to continuously and smoothly change the conveyance direction, and the curvature radius of the curved portion is used as a sheet normally used in an image forming apparatus. Is set to a relatively small radius that allows the standard recording paper to be conveyed.
As a sheet conveying apparatus in such an image forming apparatus, for example, a conventional technique described in Japanese Patent Application Laid-Open No. 2004-338923 can be cited (see Patent Document 1). That is, as shown in FIGS. 6 and 7 of the same publication, a sheet storage unit that stores a predetermined number of sheets of a predetermined size and type on each stage on the lower side of the image forming unit main body. A sheet feeding tray is arranged, and between the sheet feeding tray and the image forming unit main body, one sheet is pulled out in a substantially horizontal direction of the sheet feeding tray which is the selected stage, and the upper image forming unit main body The sheet conveying device for feeding toward is provided.

Hereinafter, the reference numerals shown in the drawings of the above-mentioned Japanese Patent Application Laid-Open No. 2004-338923 will be appropriately described in parentheses. The sheet is separated and sent out, and is conveyed to the main body of the image forming unit through a conveyance path having a curvature portion formed by the upper guide plate (8) and the lower guide plate (7). The curvature portion is formed of a curved fixed guide member including an upper guide plate (8) and a lower guide plate (7). When the sheet (P) passes through the curvature portion, the lower guide plate ( 7) As the conveyance proceeds along the sheet 7), the path of the sheet (P) is corrected so as to be pressed by the upper guide plate (8), and the elastic deformation located at the outlet of the lower guide plate (7) is achieved. The conveying roller pair (5) is reached along the possible guide piece (6). Hereinafter, the upper guide plate (8) and the lower guide plate (7) are referred to as “curved fixed guide members”.
However, in the sheet conveying apparatus configured as described above, when trying to convey a sheet of special paper (P) having high rigidity such as recording paper such as thick paper or an envelope, the radius of curvature of the curvature portion of the conveying path is small. Therefore, since the resistance when the sheet (P) is conveyed while being bent according to the curvature thereof is significantly larger than that of a sheet such as plain paper for copying, a sheet (P ) Cannot be advanced, causing jams and poor conveyance, resulting in a failure to perform a stable feeding operation.

  The above operation will be described in more detail as follows. When the sheet (P) has a leading end (front end) in the conveying direction of the sheet (P) reaches a curved fixed guide member composed of an upper guide plate (8) and a lower guide plate (7), the curved fixed guide The first half of the sheet (P) on the leading end side is curved in the thickness direction by the member. For this reason, when the highly rigid sheet (P) is conveyed, the force with which the highly rigid sheet (P) resists bending increases, and the resistance force that prevents the conveyance also increases. Therefore, the leading end of the highly rigid sheet (P) does not reach the downstream conveying roller pair (5), and the highly rigid sheet (P) is conveyed only by the upstream roller pair (2a, 2b). When the high-rigidity sheet (P) is curved by the curved fixed guide member, the resistance generated from the curved high-rigidity sheet (P) can be obtained only by the conveying force by the upstream roller pair (2a, 2b). As a result, there is a shortage of force that advances in the transport direction relative to the force. For this reason, conveyance failure such as skewing in which the center line of the highly rigid sheet (P) does not coincide with the center line of the conveyance path, or the highly rigid sheet (P) is caught by the curved fixed guide member and stopped. Paper jam is likely to occur.

Therefore, in Japanese Patent Application Laid-Open No. 2004-338923, in a sheet feeding device that conveys a sheet fed from a first conveying unit to a second conveying unit that is positioned downstream in the conveying direction and substantially vertically above. A pair of linear guide members are provided between the first conveyance unit and the second conveyance unit, and a sheet feeding device that conveys a sheet by the guide of the linear guide member has been proposed. According to this paper feeding device, since the guide member is not a curved shape but a straight linear guide member, the conveyance load can be suppressed to a low level, that is, a rapid increase in the load can be suppressed, and paper jams, skews, etc. It is said that poor conveyance can be prevented.
In other words, according to the sheet feeding device, the deformed portion on the conveyed sheet is not concentrated on one curve by the curved guide member, but near the front and rear ends of the linear guide member in the conveyance direction. Since the linear guide member is installed in a slanted posture with a substantially intermediate angle so that the degree of bending at these two places is substantially equal and the same, it can be conveyed at the time of conveyance. It is said that a sudden increase in load can be suppressed. That is, since the sheet changes its traveling direction, the curved portion is divided into two locations: a location where the sheet is delivered from the upstream roller pair to the linear guide member, and a location where the sheet is delivered from the linear guide member to the downstream roller pair. At least, the degree of bending of each portion becomes small, and accordingly, the resistance generated by bending at each portion can be kept low, so that it is possible to avoid a sharp increase in the transport load.

It has the 1st, 2nd conveyance means comprised like the said Unexamined-Japanese-Patent No. 2004-338923 (patent document 1), and it is 2nd between a 1st conveyance means and a 2nd conveyance means. 2. Description of the Related Art A reversing guide member having an inclined surface reaching a conveying unit is provided, and the reversing guide member is configured to be movable toward a second conveying unit (for example, Patent Document 2). reference).
According to this paper feeding device, when the rear end of the sheet comes into contact with the reverse guide member, the reverse guide member is displaced in a direction substantially the same as the direction in which the rear end of the paper is in contact. It is said that it can reduce the playing sound because it can absorb the shock at the time.

In addition, a plurality of sheet storage units that store sheets, a conveyance path and a sheet feeding unit that are individually provided in each sheet storage unit, and the ends of these conveyance paths merge into one common conveyance path. And at least the conveyance path provided in the sheet accommodation means that accommodates the highly rigid sheet has a different radius of curvature of the first curvature part when joining the common conveyance path provided at the end of the conveyance path. There is known a sheet feeding apparatus that is set to be larger than the radius of curvature of the other curvature portion when the conveyance paths are joined (for example, see Patent Document 3).
According to this sheet feeding device, a highly rigid sheet is curved to the same extent as an ordinary sheet when passing on the first curvature portion having a large curvature radius while traveling on the transport path. In contrast, since the sheet is continuously curved and sufficiently advanced as compared with the normal sheet, the resistance during the conveyance can be reduced, and the sheet can be conveyed by reaching the common conveyance path without causing stagnation or delay of the sheet.

The reversing roller pair has a reversing conveyance path for conveying and guiding the sheet fed by the reversing roller pair, and the reversing conveyance path has a direction changing portion for changing the sheet conveying direction. In addition, by disposing a roller that is rotatable inward in the direction changing portion in a direction perpendicular to the sheet conveying direction, the sheet fed into the reverse conveying path is sent out while being brought into contact with the roller. A sheet inverting means provided in a forming apparatus is known (for example, see Patent Document 4).
According to this sheet reversing means, the fed sheet is in the above-mentioned direction changing portion, and the inner contact portion always comes into contact with the roller, and this roller is driven to rotate as the sheet is conveyed in the conveying direction. Compared to the conventional guide plate, the conveyance resistance can be reduced, that is, the frictional resistance generated between the fixed guide member and the moving sheet is eliminated, and the guide for changing the conveyance direction at the direction changing portion. I can do it.

JP 2004-338923 A (pages 1 to 3, FIGS. 1 to 7) Japanese Patent Laying-Open No. 2005-89008 (pages 2 and 3, FIGS. 4 and 5) Japanese Patent Laid-Open No. 10-129883 (pages 1 and 2, FIG. 1) Japanese Patent Laying-Open No. 2005-1771 (pages 1 and 2, FIG. 1)

However, in the sheet conveying apparatus described in Patent Document 1, since the fixing member is arranged for guiding the sheet to be conveyed, the sheet conveying apparatus between the sheet to be conveyed and the fixed guide member is arranged. The speed difference is not eliminated, and there is a problem in that a resistance acting in a direction that hinders the conveyance of the sheet is always generated between the two regardless of the shape of the guide member and the installation posture, resulting in a conveyance load.
That is, in the conventional configuration, the effect of avoiding the above-described conveyance failure and jam is insufficient, and the linear guide member causes a conveyance load even if a rapid increase in the conveyance load can be suppressed. It can be said that there is no change. In particular, when a highly rigid sheet (sheet) such as thick paper or an envelope is conveyed, the above-described conveyance failure, jam, and the trailing sound of the sheet become noticeable.

  In the configuration provided with the reversal guide member described in Patent Document 2, even if it is a movable member in the sense that it can be displaced in the direction in which the rear end of the paper is in contact, the guide for changing the orientation of the paper is a fixed guide member. Similarly, when guiding by changing the direction, the relative speed difference between the sheet and the reverse guide member is not eliminated, and a transport load is generated. In particular, when a highly rigid sheet (sheet) such as thick paper or an envelope is conveyed, the above-described conveyance failure, jam, and the trailing sound of the sheet become noticeable.

  In addition, as in the technique described in Patent Document 3, even in a configuration in which a dedicated conveyance path having a predetermined large radius of curvature is provided, the sheet traveling on this dedicated conveyance path is gently curved so that the sheet is removed from the conveyance path. Even if the transport resistance received is reduced, the transport load is similarly generated. In particular, when transporting highly rigid paper (sheets) such as thick paper and envelopes, the above-mentioned transport failure and jamming become noticeable.

  Further, as in the technique described in Patent Document 4, in a configuration in which a movable member such as a roller is provided at a predetermined position of the inner conveyance path portion in the direction change portion of the conveyance path, in the conveyance process, by the inner roller, Even if the frictional resistance between the two in the state where the intermediate portion between the front and rear ends of the seat is supported can be particularly effectively reduced, the state before and after such a state, that is, the outside of the direction changing portion There is a lack of consideration for the conveyance load when the conveyance path portion and the sheet are in contact with each other, and no particular mention is made of the behavior of the sheet leading edge and the sheet trailing edge during the conveyance process. In particular, when a highly rigid sheet (sheet) such as thick paper or an envelope is conveyed, the above-described conveyance failure, jam, and the trailing sound of the sheet become noticeable.

  Accordingly, the applicant of the present application is an invention (hereinafter referred to as “prior application”) that aims to provide a novel sheet conveying apparatus that can solve the problems of the prior art and an image forming apparatus having the sheet conveying apparatus. Proposed). Details of the example to which the invention of the prior application is applied will be described later before the embodiment of the present invention is described. According to the present invention, a compact and space-saving, simple and low-cost configuration, a sheet conveying apparatus excellent in compatibility with sheet types (paper types), an image reading apparatus including the sheet conveying apparatus, and a sheet An image forming apparatus including a conveying device and / or an image reading device can be provided.

However, it has been found that the following problems remain in putting the invention of the prior application into practical use. That is, when trying to feed and transport relatively rigid (strong) paper (sheet) such as cardboard, the problem is that the leading edge of the paper is turned, rubbed, jammed, or poorly transported during transport. was there.
Accordingly, the present invention provides a novel sheet conveying apparatus capable of feeding and conveying a relatively high-stiff paper such as cardboard without any problem, while maintaining the advantages of space saving and low cost, and the sheet conveying apparatus. A main object is to provide an image forming apparatus provided.

  In order to solve the above-mentioned problems and achieve the above-mentioned object, the present inventors have conducted extensive studies and conducted tests and the like described in the examples of the prior application invention described below, examples, etc. A simple structure called a moving guide is conceived as a simple structure that can convey a relatively high-stiffness sheet such as cardboard or an envelope without causing any defective conveyance or jamming regardless of the type. As a specific means, belt conveying means having the simplest configuration has been variously devised and put into practical use. The present invention has been made on the basis of the results supported by such tests.

In order to solve the above-described problems and achieve the above-mentioned object, the invention according to each claim employs the following characteristic means / invention-specific matters (hereinafter referred to as “configuration”).
According to the first aspect of the present invention, the first conveying unit that conveys the sheet at the first linear velocity and the downstream side of the first conveying unit in the sheet conveying direction are conveyed by the first conveying unit. And a second conveying means for conveying the sheet in a sheet conveying direction different from the sheet conveying direction of the first conveying means, and at least a second conveying of the first conveying means and the second conveying means The means is a nipping and conveying unit that forms a nipping unit for nipping and conveying the sheet, and is disposed in a contour direction of a sheet conveying path formed between the first conveying unit and the second conveying unit, A belt conveying unit including a belt that conveys the sheet at the second linear velocity toward the clamping unit is provided, and one of the first linear velocity and the second linear velocity is relatively variable. der is, the first linear velocity as v _1, the second linear velocity v ₂ and when the approach angle of the leading edge of the sheet with respect to the belt conveyance surface is θ ₀ , after the front edge of the sheet conveyed by the first conveyance means comes into contact before contacting the belt conveyance surface. Until the sheet is held and conveyed by the clamping unit, the leading end of the sheet is at the linear velocity satisfying the relational expression of v ₂ ≧ v ₁ / sin θ ₀ or v ₂ ≈v ₁ / sin θ _0. After the sheet is nipped and conveyed by the sheet, the sheet is conveyed at a linear velocity satisfying the relational expression of v ₂ = v ₁ .

According to the second aspect of the present invention, the first conveying unit that conveys the sheet at the first linear velocity and the downstream side of the first conveying unit in the sheet conveying direction are conveyed by the first conveying unit. A second conveying unit that conveys the sheet in a sheet conveying direction different from the sheet conveying direction of the first conveying unit, and a first sheet formed between the first conveying unit and the second conveying unit A second sheet conveying path different from the first sheet conveying path, the first sheet conveying path, and the second sheet conveying formed from the conveying path, upstream of the second conveying means to the second conveying means And a merging / conveying path that merges upstream of the second conveying means, and at least the second conveying means of the first conveying means and the second conveying means sandwich the sheet. A nipping and conveying means for forming a nipping portion for conveying, A belt conveying means provided with a belt that is arranged in the outer direction of the feeding path and conveys the sheet at the second linear velocity toward the clamping portion, and is either one of the first linear velocity and the second linear velocity; one linear velocity, relatively variable der is, the first linear velocity as v _1, the second linear velocity and v _2, the entry angle with respect to the conveying surface of the belt of the front end portion of the sheet theta ₀ In this case, v ₂ ≧ after the front end of the sheet conveyed by the first conveying means comes into contact with the conveying surface of the belt and before it begins to be nipped and conveyed by the holding unit. v ₁ / sin [theta ₀ or _{v 2} ≒ _v 1 / linear velocity which satisfies the relationship of sin [theta _0, is subsequently when started to be sandwiched and conveyed by the leading edge of the sheet the sandwiching _{portion, v} 2 = v ₁ relational expression at a linear velocity which satisfies a feature to convey the sheet That is a sheet conveying apparatus.

The invention according to claim 3 is arranged on the downstream side of the first conveying means in the sheet conveying direction of the first conveying means for conveying the sheet at the first linear velocity, and has been conveyed by the first conveying means. And a second conveying means for conveying the sheet in a sheet conveying direction different from the sheet conveying direction of the first conveying means, and at least a second conveying of the first conveying means and the second conveying means The means is a nipping and conveying unit that forms a nipping unit for nipping and conveying the sheet, and is disposed in a contour direction of a sheet conveying path formed between the first conveying unit and the second conveying unit, A belt conveying unit including a belt that conveys the sheet at the second linear velocity toward the clamping unit is provided, and one of the first linear velocity and the second linear velocity is relatively variable. Where the _first linear velocity is v ₁ and the second linear velocity is v ₂ and when the entrance angle of the leading edge of the sheet with respect to the belt conveying surface is θ ₀ , v ₂ ≧ v ₁ / sin θ ₀ or v ₂ until the leading edge of the sheet contacts the conveying surface of the belt. ≈v ₁ / sin θ With a linear velocity satisfying the relational expression of ₀ , let t be an arbitrary time after the leading edge of the sheet comes into contact with the conveying surface of the belt, θ be a changing approach angle after time t, When the distance from the center of the nipping portion of one conveying means to the contact point between the perpendicular line on the conveying surface of the belt and the conveying surface is 1, the nipping is performed after the leading edge of the sheet contacts the conveying surface of the belt. until before starting is sandwiched and conveyed by the parts, _{v 2} ≧ _v 1 / sinθ or _{v 2} ≒ _v 1 / _sinθ, ^{where, θ = cos -1 {1 /} (v 1 × t / l + 1 / cosθ 0)} of At the linear velocity that satisfies the relational expression, The sheet conveying apparatus is characterized in that the sheet is conveyed at a linear velocity satisfying a relational expression of v ₂ = v ₁ after the end starts to be nipped and conveyed by the nipping unit .

According to a fourth aspect of the present invention, the first conveying unit that conveys the sheet at the first linear velocity and the downstream side of the first conveying unit in the sheet conveying direction are conveyed by the first conveying unit. A second conveying unit that conveys the sheet in a sheet conveying direction different from the sheet conveying direction of the first conveying unit, and a first sheet formed between the first conveying unit and the second conveying unit A second sheet conveying path different from the first sheet conveying path, the first sheet conveying path, and the second sheet conveying formed from the conveying path, upstream of the second conveying means to the second conveying means And a merging / conveying path that merges upstream of the second conveying means, and at least the second conveying means of the first conveying means and the second conveying means sandwich the sheet. A nipping and conveying means for forming a nipping portion for conveying, A belt conveying means provided with a belt that is arranged in the outer direction of the feeding path and conveys the sheet at the second linear velocity toward the clamping portion, and is either one of the first linear velocity and the second linear velocity; One linear velocity is relatively variable, the first linear velocity is v ₁ , the second linear velocity is v _2, and the approach angle of the leading end of the sheet with respect to the conveyance surface of the belt is θ ₀ . In this case, until the leading edge of the sheet comes into contact with the conveyance surface of the belt , the leading edge of the sheet has a linear velocity that satisfies the relational expression of v ₂ ≧ v ₁ / sin θ ₀ or v ₂ ≈v ₁ / sin θ _0. An arbitrary time after contact with the belt conveying surface is t, an approach angle after the time t is θ, and a perpendicular line from the center of the sandwiching portion of the first conveying means to the belt conveying surface and the When the distance to the contact point with the conveyance surface is l, the leading edge of the sheet After contacting the conveying surface of the belt, said up before starting is sandwiched and conveyed by the nipping portion, _{v 2} ≧ _v 1 / sinθ or _{v 2} ≒ _v 1 / _sinθ, ^{where, θ = cos -1 {1 /} ( v ₁ × t / l + 1 / cos θ ₀ )} at the linear velocity satisfying the relational expression, the relational expression of v ₂ = v ₁ is satisfied after the leading edge of the sheet starts to be sandwiched and conveyed by the sandwiching portion. A sheet conveying apparatus that conveys a sheet at a linear velocity.

According to a fifth aspect of the present invention, in the sheet conveying apparatus according to any one of the first to fourth aspects, the front end of the sheet conveyed by the first conveying unit is in contact with the conveying surface of the belt. The sheet is conveyed at a linear velocity that is higher than the first linear velocity after the contact and before it is nipped and conveyed by the nipping unit, and the leading end of the sheet is nipped by the nipping unit. The sheet is conveyed at a linear velocity equal to the first linear velocity after the beginning of conveyance .

  A sixth aspect of the present invention is the sheet conveying apparatus according to any one of the first to fifth aspects, wherein the leading edge of the sheet conveyed by the first conveying means comes into contact with the conveying surface of the belt. The second linear velocity is kept constant until the first linear velocity is changed until the clamping and conveyance are started by the clamping unit.

  The invention according to claim 7 is the sheet conveying apparatus according to claim 6, wherein the first linear velocity is changed so as to increase.

  The invention according to claim 8 is the sheet conveying apparatus according to any one of claims 1 to 5, wherein the leading edge of the sheet conveyed by the first conveying means comes into contact with the conveying surface of the belt. The first linear velocity is kept constant and the second linear velocity is changed until it is started to be sandwiched and conveyed by the sandwiching unit.

  According to a ninth aspect of the present invention, in the sheet conveying apparatus according to the eighth aspect, the second linear velocity is changed so as to decelerate.

According to a tenth aspect of the present invention, in the sheet conveying apparatus according to any one of the fifth to ninth aspects, the first linear velocity or the second linear velocity is continuously changed.

According to an eleventh aspect of the present invention, in the sheet conveying apparatus according to any one of the first to fourth aspects, the leading edge of the sheet conveyed by the first conveying unit is in contact with the conveying surface of the belt. The second linear velocity is higher than the first linear velocity, and the sheet is conveyed, and after the leading edge of the sheet conveyed by the first conveying means comes into contact with the conveying surface of the belt. Until the first linear velocity is temporarily higher than the second linear velocity, and the leading edge of the sheet is nipped / conveyed by the nipping unit. After the start, the second linear velocity is conveyed at a linear velocity equal to the first linear velocity.

  A twelfth aspect of the present invention is the sheet conveying apparatus according to any one of the first to eleventh aspects, wherein the first linear velocity detecting means for detecting the first linear velocity and the second linear velocity are detected. It has at least one of the 2nd linear velocity detection means, It is characterized by the above-mentioned.

  According to a thirteenth aspect of the present invention, in the sheet conveying apparatus according to any one of the first to twelfth aspects, the sheet is a sheet having a relatively high rigidity.

  A fourteenth aspect of the present invention is an image reading apparatus comprising the sheet conveying device according to any one of the first to thirteenth aspects.

  A fifteenth aspect of the invention is an image forming apparatus comprising the sheet conveying device according to any one of the first to thirteenth aspects and / or the image reading device according to the fourteenth aspect.

  According to a sixteenth aspect of the present invention, in the image forming apparatus according to the fifteenth aspect, the image forming apparatus includes any one of a copying machine, a facsimile, a printer, a printing machine, and an ink jet recording apparatus, or at least two of them. It is a combined multifunction device.

According to the present invention, a novel sheet conveying apparatus, an image reading apparatus including the sheet conveying apparatus, a sheet conveying apparatus and / or an image forming apparatus including the image reading apparatus are realized and provided by solving the above problems. Can do.
That is, according to the present invention, there is provided a novel sheet conveying apparatus capable of feeding and conveying a sheet having relatively high rigidity, such as cardboard, without problems even though it is space-saving and low-cost. An image forming apparatus including the image reading apparatus, the sheet conveying apparatus, and / or the image reading apparatus can be realized and provided.

The following are specific effects for each of the claimed inventions.
According to the first, second, and thirteenth aspects of the invention, when the behavior of the leading edge of the sheet when the sheet enters the belt in the sheet conveyance path or the first sheet conveyance path is considered, The leading edge of the sheet conveyed via the curvature portion having a relatively small radius of curvature in one sheet conveyance path enters at an angle that is inclined with respect to the conveyance surface of the belt. The tip of the sheet can be considered to have an apparent speed higher than that of the rear part of the sheet, for example, by the amount of advancement while bending in the outer direction of the guide member due to the strength of the waist of the sheet. Therefore, in order not to cause a problem such as turning of the leading edge of the sheet, the second linear velocity of the belt that conveys the leading edge of the sheet needs to be higher than the first linear velocity by the first conveying means. Become. On the other hand, since the linear velocity at the leading edge and the trailing edge of the sheet becomes equal after the belt is conveyed by the belt and begins to be nipped and conveyed by the clamping portion (nip portion) of the second conveying means, the second linear velocity is equal to the first linear velocity. It may be the same as the linear velocity. At this time, if the second linear velocity is increased, other problems such as rubbing at the clamping portion (nip portion) or the like may occur. Therefore, the linear velocity of one of the first linear velocity by the first conveying means and the second linear velocity by the belt conveying means is configured to be relatively variable, in other words, the first linear velocity. By changing the relative speed of the second linear velocity with the progress of the sheet, the leading edge of the sheet can be conveyed without causing problems such as turning or rubbing against the belt.
More specifically, when the sheet enters while elastically buckling with respect to the belt, the leading edge of the sheet strikes the conveying surface of the belt, and then the sheet is conveyed along the belt of the belt conveying means in order from the leading end. At that time, since the leading edge of the sheet apparently advances to the downstream side in the sheet conveying direction faster than the second linear velocity (belt conveying speed), at least when the leading edge of the sheet comes into contact with the conveying surface of the belt, When the first linear velocity is v ₁ , the second linear velocity is v _2, and the approach angle of the leading edge of the sheet with respect to the conveyance surface of the belt is θ ₀ , v ₂ ≧ v ₁ / sin θ ₀ or v clamping together, leading edge of the sheet by sandwiching portion can enter the belt without causing the problem of curling of the leading end of the sheet by a linear velocity "which satisfies the relation of ₂ ≒ v _{1 / sinθ 0} After the start of conveyance, by setting “the second linear velocity = the first linear velocity”, the conveyance can be performed without causing problems such as rubbing at the clamping portion (nip portion).
According to the invention described in claims 3, 4 and 13, in addition to the effect of the preceding stage (the effect excluding the effect described more specifically) according to the invention of claims 1, 2 and 13, the following effect is obtained. .
More specifically, since the leading edge of the sheet apparently advances to the downstream side in the sheet conveying direction faster than the second linear velocity (belt conveying speed), at least the leading edge of the sheet contacts the conveying surface of the belt. “When the first linear velocity is v ₁ , the second linear velocity is v _2, and the approach angle of the leading end of the sheet with respect to the conveyance surface of the belt is θ ₀ , v ₂ ≧ v ₁ / By making the linear velocity satisfying the relational expression of sin θ ₀ or v ₂ ≈v ₁ / sin θ ₀ , it is possible to enter the belt without causing the problem of turning up of the front end of the sheet, and then the belt Since the sheet entry angle with respect to the belt changes with time in a state where the leading edge is being conveyed, “any time after the leading edge of the sheet contacts the conveying surface of the belt is defined as t, and changes after the time t” When the approach angle is θ and the distance from the center of the first conveying means to the contact point between the perpendicular line on the belt conveyance surface and the belt conveyance surface is l, the leading edge of the sheet is the belt conveyance surface. after contact with, until before starting is sandwiched and conveyed by the clamping portion, _{v 2} ≧ _v 1 / sinθ or _{v 2} ≒ _v 1 / _sinθ, ^{where, θ = cos -1 {1 /} (v 1 × t / l + 1 When the linear velocity satisfying the relational expression of / cos θ ₀ )} ”, the leading edge of the sheet can be conveyed without being turned during the belt conveyance, and after the leading edge of the sheet starts to be nipped and conveyed by the clamping unit, By setting “linear velocity satisfying the relational expression of v ₂ = v ₁ ”, it can be conveyed without causing problems such as rubbing at the clamping part (nip part).

According to the fifth and thirteenth aspects of the invention, when the sheet enters the belt while elastically buckling, the leading end of the sheet hits the conveying surface of the belt, and thereafter, along the belt of the belt conveying means in order from the leading end. At that time, the leading edge of the sheet apparently advances to the downstream side in the sheet conveying direction faster than the second linear velocity (belt conveying velocity). It is possible to carry the sheet without causing a problem of turning up of the tip by setting it as “first linear velocity”, and after clamping (nip) to the second conveying means, “second linear velocity = first linear velocity”. By setting the “speed”, it can be conveyed without causing problems such as rubbing at the nipping (nip) portion.

  According to the sixth, seventh and thirteenth aspects of the present invention, the first linear velocity is changed by changing the first linear velocity as a method of changing the relative linear velocity between the first linear velocity and the second linear velocity. The linear speed and the relative speed of the second linear speed by the belt conveying means can be changed with a simple configuration, thereby producing effects such as space saving and cost reduction.

  According to the eighth, ninth and thirteenth aspects of the present invention, the first linear velocity is changed by changing the second linear velocity as a method of changing the relative velocity between the first linear velocity and the second linear velocity. It is possible to change the relative linear speed between the linear speed and the second linear speed by the belt conveying means with a simple configuration, thereby producing effects such as space saving and cost reduction.

  According to the tenth and thirteenth aspects of the invention, when considering the behavior of the leading edge of the sheet when the sheet enters the belt in the sheet conveying path or the first sheet conveying path, the leading edge of the sheet is, for example, a guide. Since it moves along the member and changes the approach angle, it changes with the conveyance. Therefore, by continuously changing the first linear velocity or the second linear velocity, the sheet leading edge is turned over. In addition to preventing this, the sheet can be conveyed without causing a problem of rubbing at the front end of the sheet.

  According to the eleventh and thirteenth aspects of the present invention, after the leading edge of the sheet conveyed by the first conveying means comes into contact with the conveying surface of the belt and before the nipping / conveying operation starts, the first Since the linear velocity of 1 is temporarily higher than the second linear velocity, the sheet can be pushed from the rear, and as a result, the leading edge of the sheet is pushed up toward the conveying surface of the belt by the waist of the sheet. The position of the leading edge of the sheet can be aligned toward the belt belly, and the skew of the leading edge of the sheet is corrected, and the effect of (pre) resist can be realized.

  According to invention of Claim 12 and 13, it has at least one of the 1st linear velocity detection means which detects 1st linear velocity, and the 2nd linear velocity detection means which detects 2nd linear velocity. Thus, it is possible to carry the sheet while maintaining at least one of the relative velocity relationship of the first linear velocity with respect to the second linear velocity and the relative velocity relationship of the second linear velocity with respect to the first linear velocity.

  According to the fourteenth aspect of the present invention, the image reading apparatus having the sheet conveying apparatus according to any one of the first to thirteenth aspects includes an automatic document feeder (ADF) that automatically feeds a document sheet. By using the image reading apparatus, it is possible to improve the transportability of the sheet document in the automatic document feeder.

  According to the fifteenth aspect of the present invention, as an image forming apparatus having the sheet conveying apparatus according to any one of the first to thirteenth aspects and / or the image reading apparatus according to the fourteenth aspect, a sheet conveying apparatus and / or The sheet and / or sheet document transportability in the automatic document feeder can be improved.

  According to the sixteenth aspect of the present invention, the image forming apparatus is an image forming apparatus of any one of a copying machine, a facsimile machine, a printer, a printer, and an ink jet recording apparatus, or an image of a complex machine combining at least two of them. In the forming apparatus, it is possible to provide an apparatus capable of obtaining stable sheet transportability even with a relatively high-stiffness cardboard sheet (transporting a stiff sheet such as cardboard sheet without causing problems such as turning and rubbing). .

Hereinafter, embodiments of the present invention (hereinafter referred to as “embodiments”) including the best mode for carrying out the present invention will be described with reference to the drawings. Constituent elements such as members and components having the same function and shape, etc. over the examples, embodiments, modifications, examples, etc. of the sheet conveying device to which the above-mentioned invention of the prior application is applied and the image forming apparatus equipped with the same. Will be omitted after having been described once by assigning the same reference numerals. In order to simplify the drawings and the description, even components that are to be represented in the drawings may be omitted as appropriate without being specifically described in the drawings. When a constituent element such as a published patent gazette is cited and explained as it is, the reference numeral is attached with parentheses to distinguish it from that of each embodiment.
Hereinafter, in "Best Mode for Carrying Out the Invention", the first embodiment is referred to as "first reference example", the second embodiment is referred to as "second reference example", and the first embodiment. The first modification of the first embodiment is “reference modification 1 of the first reference example”, the second modification of the second embodiment is “reference modification 2 of the second reference example”, and the third embodiment is “ First Embodiment ”, Fourth Embodiment as“ Second Embodiment ”, Third Modification of Third Embodiment as“ Modification 1 of First Embodiment ”, and Fourth Implementation The modified example 4 of the embodiment is read as “modified example 2 of the second embodiment”, and the fifth embodiment is read as “third embodiment”.

  FIGS. 8 to 10 to be described later including FIGS. 1 to 5 and the like include examples of a sheet conveying device to which the above-mentioned invention of the prior application is applied and an image forming apparatus on which the sheet conveying device is mounted. explain in detail. First, an overall configuration of a copying machine 1 as an example of an image forming apparatus will be described with reference to FIG.

The copying machine 1 is a monochrome copying machine that reads an image from the surface of a document and forms a copy image on recording paper, transfer paper, paper, OHP film, etc. as various sheet-like recording media (hereinafter referred to as “sheets”). is there. The copying machine 1 includes an image forming apparatus main body 2 having an image forming unit that performs a predetermined image forming process based on a read original image, and the image forming apparatus main body 2 mounted thereon. As an example, a sheet feeding device 3 that supplies sheets S one by one, and a document reading device 4 that is mounted on the image forming apparatus main body 2 reads a document image and sends the document image information to the image forming apparatus main body 2. Have.
A paper discharge tray 9 for discharging and stacking paper that has passed through the image forming apparatus main body 2 is installed in the upper part of the image forming apparatus main body 2 and below the document reading device 4 so as to supply paper. A paper transport path R1 (hereinafter also referred to as “transport path R1”) is formed as a paper transport path (sheet transport path) for moving the paper S from the paper device 3 to the paper discharge tray 9. Most of the transport path R1 extends from the sheet feeding device 3 to the upper part of the image forming apparatus main body 2, and extends in a substantially vertical upward direction, that is, a substantially vertical upward direction with respect to a substantially horizontal line, and the transport path R1. On the top, there are provided sheet conveying means as several sheet conveying means which are configured by a pair of conveying rollers, a pair of rollers, etc. with a predetermined interval corresponding to the minimum size sheet S. Any one of these sheet conveying means is configured to always convey the sheet S on the conveying path R1 by nipping or the like. Further, the sheet feeding device 3 is provided with a sheet conveying device 5 as a sheet conveying device for feeding and conveying the sheets S accommodated in the respective stages of the sheet feeding device 3 to the conveying path R1.

  In the image forming apparatus main body 2, a photosensitive unit 10 as an image forming unit for forming an image and a fixing device 11 are sequentially arranged from the upstream side to the downstream side of the conveyance path R <b> 1. After the photoreceptor unit 10 transfers the generated toner image to the sheet S conveyed from the upstream side to the downstream side on the conveyance path R1, the fixing device 11 transfers the transferred toner image. The sheet S fixed on the sheet S and fixed with the toner image is discharged to a sheet discharge tray 9 disposed at the end of the transport path R1.

The photoconductor unit 10 has a single drum-like photoconductor 10A as an image carrier, and can be rotated to a side plate (not shown) in the image forming apparatus main body 2 around a rotation shaft arranged substantially horizontally. It is supported by. The photoconductor 10A has a known configuration formed in a cylindrical shape with a predetermined diameter. The photosensitive member 10A is stabilized in the rotational direction indicated by an arrow in the drawing when a rotational driving force is transmitted from a driving source such as a motor provided on either the photosensitive unit 10 side or the image forming apparatus main body 2 side. It is driven to rotate at a constant speed.
Around the photoconductor 10A, a developing device 12, a transfer device 13, a photoconductor cleaning device 18, a static eliminator, and a charging device 14 are arranged in the rotation direction indicated by the arrows in the drawing. Within the range of one rotation in the counterclockwise rotation direction, the development position, the transfer position, the cleaning position, the charge removal position, and the charging position are sequentially applied from the upstream to the downstream by each of these devices 12 to 14, respectively. Is set.
Further, a latent image forming position is set between the charging position and the developing position, and exposure is performed to write an invisible latent image corresponding to image information by irradiating the latent image forming position with a predetermined laser beam. The device 47 is disposed obliquely below and slightly away from the photoconductor unit 10. Then, the photoconductor 10A is rotationally driven in a predetermined counterclockwise direction, and each of the devices 12 to 14 and the exposure device 47 perform a cooperative operation in a predetermined manner in synchronization with the rotation of the photoconductor 10A. Thus, a series of image forming processes are executed.

That is, the developing device 12 has an appropriate well-known configuration such as a developing roller that generates a toner brush in which toner particles are erected radially from the surface thereof, and is generated at a predetermined location on the surface of the photoreceptor 10A. The toner particles at the tip of the toner brush are attached to the latent image that moves around the circumference and passes through the developing position with the rotation of 10A, and the invisible latent image is visualized as a monochrome toner image.
The transfer device 13 includes two support rollers 15 and 16 that are opposed to each other with a predetermined spacing in a substantially vertical direction, and a transfer belt 17 that is an endless belt stretched between the support rollers 15 and 16. Then, the toner image on the outer peripheral surface of the photoreceptor 10A is transferred to the sheet S, and the sheet S on which the unfixed toner image is transferred is conveyed to the downstream side of the conveyance path R1. That is, the lower support roller 16 has its portion around which the transfer belt 17 is wound pressed against an approximately right diagonally lower portion of the photoconductor 10A, so that the transfer belt 17 is in contact with the surface of the photoconductor 10A and the transfer belt 17. The position is set. The upper support roller 15 is disposed in front of the introduction port of the fixing device 11.

The photoconductor cleaning device 18 is a blade material (not shown) configured such that the blade edge at the tip thereof is in contact with the cleaning position on the photoconductor 10A with a predetermined pressure, or the photoconductor is in contact with the cleaning position. It has one or both of the configurations of a rotating brush that rotates following the rotation of 10A, and removes toner, foreign matter, etc. remaining on the surface of the photoreceptor 10A after transfer.
The static eliminator is mainly composed of a lamp capable of emitting light of a predetermined intensity. The static elimination position is irradiated from this lamp to the static elimination position, and the charged state on the surface of the photoreceptor 10A passing through the static elimination position is determined. The surface potential of the photoconductor 10A after being released and passing through the transfer position is returned to the initial state.

The fixing device 11 includes a heating roller 31 having a built-in electric heater as a heat source, and a pressure roller 32 disposed to face the heating roller 31 in a substantially horizontal direction and pressed and urged toward the heating roller 31. When the heating roller 31 is rotationally driven by a driving source such as a motor (not shown), the pressure roller 32 in contact therewith is driven to rotate, and at a place where both the rollers 31 and 32 are in contact, a predetermined heating temperature is set. A nip portion for fixing the toner image on the sheet is formed by securing the applied pressure.
In the figure, reference numeral 20 denotes a toner storage container composed of a toner bottle or the like that stores new or new toner. A toner transport path (not shown) is formed from the toner storage container 20 to the developing device 12. When the developing device 12 consumes its own toner for development and becomes insufficient, new toner is replenished from the toner container 20 to the developing device 12.

  Below the image forming apparatus main body 2 is provided a paper feeding device 3 that can selectively select a paper size (sheet size) automatically or manually by a user according to the size of a document to be read. Yes. That is, the sheet feeding device 3 stores and arranges a plurality of sheet feeding trays 51 and 51 as sheet storing means in multiple stages in the sheet feeding device 3 and feeds each sheet feeding tray 51 and 51 individually. It is configured to be able to be pulled out of the apparatus 3, and the paper for the tray can be set in each paper feed tray 51 and an appropriate number of sheets can be replenished. Each of the paper feed trays 51 and 51 stores and stores a large number of sheets S having different sheet types (sheet types) in various vertical sizes and horizontal directions with respect to various sheet sizes and sheet conveyance directions (sheet conveyance directions). ing.

The document reading device 4 has a reading device main body 4A that forms the framework, and a contact glass 57 is disposed over a predetermined range on the upper surface of the reading device main body 4A. In the reading device main body 4A, reading means for optically reading a document image with a predetermined range on the surface of the contact glass 57 as a scanning target is housed. The reading means includes at least the first traveling body 53, the first traveling body 53, and the like. 2 is mainly composed of a traveling body 54, an imaging lens 55, and a reading sensor 56 such as a CCD.
In the document reading device 4, a document pressing plate 58 configured to be openable and closable between a closed position that covers the contact glass 57 and an open position that opens is provided on the upper surface of the reading device main body 4A. That is, the document pressing plate 58 is formed in a vertical and horizontal dimension larger than that of the contact glass 57, and one end of the original pressing plate 58 is supported on the upper surface of the reading apparatus main body 4A by a hinge (not shown) so as to be opened and closed.

  Based on the configuration described above, the operation of the copying machine 1 will be described. First, when copying a document with the copying machine 1, the user manually opens the document pressing plate 58 of the document reading device 4 from the closed position to the open position, and places and sets the document on the contact glass 57. The document pressing plate 58 is manually operated in the closing direction, and the document set on the contact glass 57 is pressed from above by the document pressing plate 58. By this operation, the original is brought into close contact with the contact glass 57 and spread in a flat shape so that the original surface can be read accurately, and the original is fixed on the glass 57.

  When the user depresses / turns on a start switch installed in an operation screen (not shown) provided in advance in the copying machine 1, the reading operation of the document reading device 4 is immediately started, and a drive mechanism (not shown) The first traveling body 53 and the second traveling body 54 are traveled. Then, the light from the light source of the first traveling body 53 is irradiated toward the document, the reflected light from the document surface is directed to the second traveling body 54, and the reflected light is reflected by the mirror of the second traveling body 54. The image is input to the reading sensor 56 through the imaging lens 55. As a result, the reading sensor 56 photoelectrically converts an image of the document and the like and reads it.

  When the start switch is turned on as described above, the photoconductor 10A of the photoconductor unit 10 starts rotating, and an operation for forming a toner image on the photoconductor 10A based on the read original image. Is started. That is, as the photoconductor 10A is rotated, predetermined portions on the outer peripheral surface of the photoconductor 10A are sequentially arranged between the charging device 14, the exposure device 47, the developing device 12, the transfer device 13, the photoconductor cleaning device 18, and the charge eliminating device. After passing through the respective positions set in step 1, the toner is sequentially charged to a predetermined charged state, a latent image is generated, visualized as a toner image, transferred to the paper S, and the residual toner is removed. The charging state is released, one cycle is completed, and the cycle is predetermined so that a toner image is generated in a predetermined length range of the outer peripheral surface in the rotation direction of the photoconductor 10A according to the image size to be formed. Persisted.

When the start switch is pressed, the operation of the sheet conveying device 5 attached to the sheet feeding stage from the sheet feeding tray 51 of the sheet feeding stage storing the automatically or manually selected sheet S in the sheet feeding apparatus 3 is operated. Thus, one sheet S is conveyed to the conveyance path R1 via a predetermined sheet conveyance path (sheet conveyance path). The sheet S is conveyed by a conveying roller or the like on the conveying path R1 in the image forming apparatus main body 2 substantially vertically upward, and the leading edge of the sheet S abuts against the registration roller pair 21 and temporarily stops.
On the other hand, in the case of manual paper feed, the paper S set on the manual feed tray 67 is first fed out by the rotation of the paper feed roller 67A for the manual feed tray, and when a plurality of paper S are stacked and set. The paper is separated into one sheet by the separation rollers 67B and 67C for the manual feed tray, conveyed to the manual sheet feed path R2, and further conveyed from the manual sheet feed path R2 to the conveyance path R1. Stops at 21.
Then, the registration roller pair 21 starts to rotate at an accurate timing according to the relative movement of the toner image on the photoconductor 10A that has been rotationally driven, and sends the temporarily stopped paper S to the transfer position. As a result, the toner image is transferred onto the paper S by the transfer device 13.

  The sheet S to which the unfixed monochrome toner image is transferred in this way is conveyed to the fixing device 11 by the transfer belt 17 of the transfer device 13 that forms a part of the conveying path R1, and passes through the nip portion formed by the fixing device 11. Then, predetermined heat and pressure are applied by the nip portion, whereby the image is fixed on the paper S. The sheet S on which the image is fixed is guided by the switching claw 34 toward the conveyance path R1 reaching the discharge tray 9 and is discharged onto the discharge tray 9 by the discharge rollers 35 to 38. Stacked. Then, the user can take out the paper stacked on the paper discharge tray 9 from the opening portion on the front side of the apparatus between the paper discharge tray 9 and the document reading device 4.

  Further, when the duplex copy mode is selected by the user's setting input, the sheet S on which the image is fixed on one side is conveyed to the sheet reversing device 42 side by the switching claw 34 and is arranged in the sheet reversing device 42. A plurality of pairs of rollers 66 and a guide member (not shown) are moved back and forth on the reverse conveyance path R3 to reverse the vertical direction of the paper surface, and then the resist is registered from a position positioned in front of the photosensitive unit 10. After returning to the conveyance path R1 via the roller pair 21, the sheet is conveyed on the conveyance path R1 and guided again to the transfer position. This time, after the image is transferred and fixed on the back surface of the sheet S, the discharge rollers 35 to 38 are used. The paper is finally discharged onto the paper discharge tray 9.

(First example)
Next, a characteristic configuration of the sheet conveying apparatus 5 (hereinafter also referred to as “first example”) to which the sheet conveying apparatus according to the invention of the prior application is applied will be described.
As shown in FIGS. 2 and 3, the sheet transport device 5 has a large number of sheets S stacked and accommodated in a predetermined tray (lower in this example) of the sheet feed tray 51 in the sheet feeder 3 shown in FIG. 1. One sheet S is pulled out from the sheet S, the sheet conveying direction (sheet conveying direction) of the drawn sheet S is changed, and the sheet S is fed to the image forming apparatus main body 2 substantially vertically above.

  The sheet conveying device 5 is disposed on the downstream side of the first conveying unit (hereinafter referred to as “first conveying unit”) 6 that conveys the sheet S and the sheet conveying direction (sheet conveying direction) of the first conveying unit 6. A second transport means (hereinafter referred to as “second transport means”) 7 for transporting the paper S transported by the first transport means 6 in a paper transport direction different from the paper transport direction of the first transport means 6; Each of the first conveying means 6 and the second conveying means 7 is configured as a nipping and conveying means for nipping and conveying the sheet S by a pair of conveying rotating members, that is, the first conveying means 6 is a feed roller 61. And a reverse roller 62. The second conveying means 7 is composed of two conveying rotating members disposed opposite to each other. The second conveying means 7 includes a grip roller 81, a roller-shaped pulley 83, and a roller-shaped pulley 84. Stretched between The second conveying rotary member pair is composed of two conveying rotary members disposed opposite to the conveying belt 82, and one of the second conveying rotary member pairs is kept in contact with the leading edge of the paper S. However, it is a belt conveying means 8 (movement guiding means) provided with a conveying belt 82 that moves and guides the paper S toward a clamping section (to be described later) of the second conveying means 7, and the conveying belt 82 in the belt conveying means 8. A conveying surface 82a, which is a belt traveling surface formed on the upper surface, is an outer periphery of the first conveying path A as a sheet conveying path (sheet conveying path) formed between the first conveying means 6 and the second conveying means 7. It is characterized by being arranged at a position deviating in the direction.

As described above, the paper conveyance direction of the first conveyance rotation member pair including the feed roller 61 and the reverse roller 62 and the paper conveyance direction of the second conveyance rotation member pair including the grip roller 81 and the conveyance belt 82 are: Different from each other, that is, the sheet conveying direction of the first conveying rotating member pair is set to a substantially horizontal direction which is an upper right diagonal direction in FIGS. 2 and 3, whereas the sheet conveying direction of the second conveying rotating member pair is The direction is set substantially vertically upward. Thus, the first conveyance path A formed between the first conveyance means 6 and the second conveyance means 7 is a curved curvature having a small curvature radius that causes the paper conveyance direction to change rapidly in the first conveyance path A. Forming part.
Here, the respective paper transport directions of the first and second transport means 6 and 7 are strictly expressed as follows. That is, with reference to FIG. 6, the sheet conveying direction of the first conveying unit 6 includes the rotation center of the feed roller 61, the rotation center of the reverse roller 62, and the nipping portion (nip portion) of the feed roller 61 and the reverse roller 62. ) In the substantially horizontal direction perpendicular to the center of the nip portion in the line segment connecting the three points with the center.
Similarly, the sheet conveying direction of the second conveying means 7 includes three points: the rotation center of the grip roller 81, the rotation center of the pulley 83, and the center of the gripping portion (nip portion) of the grip roller 81 and the conveying belt 82. It is set in a substantially vertical upward direction perpendicular to the center of the nip portion in the connecting line segment.

  In other words, in the paper transport path formed between the first transport means 6 and the second transport means 7 and configured to change the paper transport direction, the thickness of the paper S constituting and transporting the paper transport path Of the pair of opposing surfaces that define the direction of the direction, the surface on the side where the leading edge of the paper S sent out from the first conveying means 6 abuts is at least the part where the leading edge of the paper S abuts. Thus, a predetermined range from the longitudinal direction of the paper conveyance direction to the second conveyance unit 7 is configured as a conveyance guide surface that continuously and constantly moves in a direction approaching the clamping portion of the second conveyance unit 7. The conveying guide surface is formed by a belt running surface (conveying surface 82a) formed on the conveying belt 82 in the belt conveying means 8. In addition, the range surrounded by the extension line along the paper conveyance direction of the first conveyance means 6 and the extension line along the paper conveyance direction of the second conveyance means 7 is an inner outline, and the other is the outer outline. The conveying surface 82a of the conveying belt 82 used for conveying the sheet formed by the flat belt running surface is disposed at a position deviated from the inner contour in the outer contour direction, and generally intersects the paper traveling direction. Has been extended to.

As shown in FIGS. 3 and 4, the belt conveying means 8 includes a conveying belt 82, a grip roller 81 and a conveying belt 82 for holding the conveying belt 82 so as to be able to travel and for passing the conveying belt 82. The roller-like pulley 83 as the first belt holding and rotating member disposed facing the nipping portion (nip portion) of the roller, and the sheet conveying direction of the second conveying means 7 facing the pulley 83. And the above-described roller-like pulley 84 as the second belt holding and rotating member disposed on the upstream side. In the present example, a single example of the second belt holding and rotating member is shown.
In the belt conveyance unit 8, the leading edge of the sheet S conveyed by the first conveyance unit 6 abuts on the conveyance surface 82 a of the conveyance belt 82 excluding the portion of the conveyance belt 82 held by the pulley 83 and the pulley 84. It is important to arrange them so that they are in contact. In this way, the belt is conveyed such that the shaft center of the pulley 84 (the center of the pulley shaft 84a) is located above the lower end position of the reverse roller 62 and below the height of the downstream end of the conveyance guide member 71. By disposing the means 8, the leading edge of the sheet S collides with the belly portion of the conveyance belt 82 (the portion that should be called “effective conveyance surface”), so that the stable elastic displacement of the conveyance belt 82 is stable. A deformed state is obtained, and the state in which the leading end of the sheet S is reliably in contact with the transport surface 82a of the transport belt 82 without being repelled is maintained, and the effects described below can be obtained. it can.
On the other hand, when the leading edge of the paper S is arranged so as to be in contact with (contact with) the conveyor belt 82 held by the pulley 83 and the pulley 84 of the conveyor belt 82, the conveyor belt 82 is connected to the pulley 83. The conveyor belt 82 portion held by the pulley 84 is generally harder than the belly portion of the conveyor belt 82 and is less elastically displaced and deformed. In this case, it is not preferable because it repels or a stable and appropriate elastic displacement / deformation state cannot be obtained. The same applies to each of the examples to which the invention of the prior application described later is applied, and the embodiments, modifications, examples, etc. to which the invention of the present application is applied (hereinafter also referred to simply as “the same”).

Further, as shown in FIG. 6, the belt conveying unit 8 causes the leading edge of the sheet S conveyed by the first conveying unit 6 to enter the conveying surface 82 a of the conveying belt 82 with an acute entry angle θa. It is also important to place them in By disposing the belt conveying means 8 in this manner, the leading edge of the sheet S stably contacts the above-described antinode portion of the conveying belt 82, so that the leading edge of the sheet S is reliably brought into contact with the conveying surface 82 a of the conveying belt 82. The state of abutting on is maintained, and the effects described below can be obtained.
In the case where the leading edge of the sheet S is arranged so as to enter the conveying surface 82a of the conveying belt 82 with a rush angle θa substantially perpendicular to or perpendicular to the conveying surface 82a, the leading edge of the sheet S enters the conveying surface 82a of the conveying belt 82. This is not preferable because the contact state becomes unstable, for example, it is bent in the direction opposite to the traveling direction of the conveyor belt 82 or repulsion is caused (the same applies hereinafter).

The paper feed trays 51 of each stage in the paper feed device 3 are formed in a substantially flat box shape having an upper opening, ensuring a planar shape capable of storing the maximum size paper S that can be handled by the copying machine 1. A bottom plate 50 as a sheet stacking unit is provided on the bottom surface. The bottom plate 50 is attached and fixed to a horizontal shaft 50A supported at the base end portion on the left side of FIG. The free end portion is configured to be swingable within the sheet feed tray 51 about the shaft 50A.
In addition, a recess having a predetermined shape is formed at the bottom of the paper feed tray 51, and the rising arm 52 is stored in the recess. The ascending arm 52 is fixed to a horizontal shaft 52A that is supported so that its base end is pivotable within the recess within a predetermined angular range, that is, is swingable, and the horizontal shaft 52A has a rotation (not shown). When the rotational driving force in an arbitrary rotational direction is transmitted from the driving source and rotated, the ascending arm 52 is driven to swing so as to occupy a predetermined tilted position about the horizontal shaft 52A. As a result, the free end portion of the raising arm 52 pushes up the bottom plate 50, and the one side periphery of the uppermost surface of the paper S placed on the bottom plate 50 is kept at a predetermined height position.

As described above, the paper feed tray 51 loads and stores the sheets S on the bottom plate 50 and raises the stacked sheets S by raising and tilting the free end portion on the right end side in the figure of the bottom plate 50. Even when the sheets S are fed one by one and the number of stacked sheets decreases, the uppermost surface is maintained at a predetermined height.
As described above, the paper feed tray 51 is configured to be attachable / detachable / removable with respect to the main body of the paper feeder 3. That is, the paper feed tray 51 is inserted into the main body of the paper feeding device 3 as shown in FIG. It is configured to be able to selectively occupy the separation position where the paper S can be replenished or the size of the paper S can be exchanged by being pulled out / removed to the front side.
Further, at least the first transport unit 6, the second transport unit 7, and the paper transport path (transport path) arranged between the first transport unit 6 and the second transport unit 7 are when the paper feed tray 51 is pulled out. Left in the body. Therefore, in this example, it is an in-body discharge type image forming apparatus, but by providing the movement guide means, the above-mentioned conveyance path can be conveyed with the same curvature as the conventional one or less, so the width direction of the apparatus is Without increasing the size, the advantage of the in-body discharge type can be prevented from being reduced.

The pickup roller 60 is rotatably supported by the housing 80 that forms the outer shape of the main body of the paper feeding device 3 so as to contact the uppermost surface of the paper S that has been raised to a predetermined height. A paper feed separation mechanism for separating and feeding the paper S into a single sheet is positioned on an extension line along the drawing direction of the paper S by the pickup roller 60. This paper feed separation mechanism is reverse to the feed roller 61. The roller 62 is configured to form a nip portion that is in contact with a predetermined pressure.
As shown in detail in FIG. 3, the pickup roller 60 is a well-known one that is integrally fixed around a shaft 60a that is integrally formed with a core metal (not shown), and is rotatable with the shaft 60a. A one-way clutch (not shown) is provided between the shaft 60a and the metal core, and is supported so as to rotate freely with respect to the shaft 60a when not driven. A soft high-friction material such as rubber having a high friction coefficient with respect to the paper S is used for the outer peripheral portion including the outer peripheral surface of the pickup roller 60 so that the pick-up roller 60 can be easily picked when contacting the paper S. In addition, on the outer peripheral surface portion of the pickup roller 60, there may be a case where a substantially saw-tooth shaped protrusion is formed on the entire circumference in order to increase the frictional resistance as appropriate.

  In this example, for example, an FRR (Feed Reverse Roller) paper feeding method, which is a reverse separation method, is adopted as a paper feeding method (sheet feeding method) that separates and feeds stacked paper S into one sheet without double feeding. is doing. That is, when two or more sheets S are pulled out by the pickup roller 60, the sheet S is separated into one sheet S in contact with the feed roller 61 and other sheets S in contact with the reverse roller 62, The feed roller 61 advances and feeds one sheet S as it is in the sheet conveying direction, while the reverse roller 62 advances another sheet in the direction opposite to the sheet conveying direction to return to the original stacked position. In addition, the reverse roller 62 is configured not to interfere with the sheet conveyance by the feed roller 61.

More specifically, the sheet feed separation mechanism using the FRR sheet feed method as the sheet separation mechanism is in contact with a feed roller 61 that is rotationally driven in a forward direction that advances in the sheet conveyance direction, and a lower side of the feed roller 61. , A reverse roller 62 that is driven in reverse by a rotational driving force transmitted in the reverse rotation direction via a torque limiter is provided, and the feed roller 61 is in contact with the uppermost sheet S on the bottom plate 50, The reverse roller 62 is in contact with the lower surface of the paper S in contact with the feed roller 61 regardless of whether two or more sheets are present.
The feed roller 61 is integrally fixed around a shaft 61a formed integrally with a core metal (not shown), and can be rotated together with the shaft 61a. Sometimes. In the outer peripheral portion including the outer peripheral surface of the feed roller 61, a rubber having a high coefficient of friction with respect to the paper S so that it can be easily sent out in the paper transport direction when it contacts the paper S, like the pickup roller 60. Such a soft high friction material is used. Also, the outer peripheral surface portion of the feed roller 61 may be formed with substantially saw-tooth shaped protrusions on the entire circumference in order to increase the frictional resistance as appropriate.
The reverse roller 62 is formed integrally with a metal core (not shown), and is rotatably supported by the housing 80 together with the reverse roller drive shaft 62a via the torque limiter.

In the FRR sheet feeding method, a weak torque in the reverse rotation direction with respect to the feed roller 61 is applied to the reverse roller 62 via a torque limiter (not shown). Accordingly, when the reverse roller 62 is in contact with the feed roller 61 or when one sheet S enters between the rollers 61 and 62, the reverse roller 62 rotates with the feed roller 61. That is, by the action of the torque limiter, for example, the reverse roller 62 slips with respect to the reverse roller drive shaft, and, similarly to the feed roller 61, the reverse roller 62 rotates in the forward direction that advances in the paper feeding direction. On the other hand, when the feed roller 61 is separated or when two or more sheets S enter between the rollers 61 and 62, the reverse roller 62 rotates in the reverse direction. For this reason, when the multi-feed paper S enters, other paper S in contact with the reverse roller 62 other than one paper S in contact with the feed roller 61 which is the uppermost paper S is upstream in the paper transport direction. Thus, the double feeding of the paper S is prevented.
Accordingly, the transport force supplied from the reverse roller 62 to the paper S that is in contact with the reverse roller 62 ensures that the transport force in the reverse direction is sufficient to return the paper S to the original stacking position. The conveying force supplied to the sheet S from the feed roller 61 for advancing S in the forward direction is set to a predetermined value so as not to prevent the sheet conveyance in the forward direction by the feed roller 61. For this reason, the so-called transport force supplied to the paper S from the feed roller 61 is reduced by the reverse transport force from the reverse roller 62.

  In the figure, reference numeral 65 denotes an idler gear coupled to a drive shaft that outputs a rotational driving force from a drive source provided on the main body side of the sheet feeding device 3, and the sheet feeding device is engaged by meshing between the gears or belt transmission. 3 is distributed and transmitted to the pickup roller 60 and the feed roller 61 so that the pickup roller 60 and the feed roller 61 are respectively rotated at a predetermined speed.

A grip roller 81 which is the other transport rotation member of the second transport rotation member pair in the second transport means 7 is disposed obliquely above the feed roller 61 via a rotation drive shaft 81 a formed integrally with the grip roller 81. The housing 80 is rotatably supported and arranged. The outer peripheral portion including the outer peripheral surface of the grip roller 81 also has a high coefficient of friction with respect to the paper S so that it can be easily sent out in the paper transport direction when it comes into contact with the paper S, like the feed roller 61. Soft high friction materials such as rubber are used.
In the vicinity of the grip roller 81, the pulley 83 is rotatably supported by the housing 80 so as to be in contact with the outer peripheral surface of the roller 81 via the conveying belt 82 and faces the grip roller 81 in the horizontal direction. Is arranged.
The pulley 83 is formed integrally with the pulley shaft 83a and is rotatably supported by the housing 80 together with the pulley shaft 83a. Below the pulley 83 diagonally to the left, the pulley 84 described above that is rotatably supported by the housing 80 is disposed. The pulley 84 is formed integrally with the pulley shaft 84a and is rotatably supported by the housing 80 together with the pulley shaft 84a. The pulleys 83 and 84 have a function as a belt holding and rotating member that supports the conveyor belt 82 so as to run and rotate.

The arrangement of the belt conveying means 8 is not limited to the arrangement state described above, and may be as follows. That is, in FIG. 3, reference numeral 79 shown with parentheses indicates an open / close guide configured to be openable and closable with respect to the housing 80 as a part of the main body of the sheet conveying device 5. The opening / closing guide 79 is integrated (unitized) with a conveyance guide member 72 and a belt conveyance unit 8 to be described later, and is formed on the first conveyance path A or a vertical conveyance path extending substantially vertically upward. In order to make it easier for the user to handle jams, jams, etc., the conveyor belt 82 can be opened and closed so as to be able to contact and separate with respect to the grip roller 81 around a hinge fulcrum shaft (not shown) below the housing 80. It is configured.
When such an opening / closing guide 79 is provided, the pulley 83 and the pulley 84 are rotatably supported on the opening / closing guide 79 side together with the pulley shafts 83a and 84a.

Although the conveyance belt 82 is partially described above, it is an endless belt and is stretched between the pulleys 83 and 84. The distance between the shafts of the pulleys 83 and 84 is set in advance. The linear belt running surface (conveying surface 82 a) of the conveying belt 82 formed between the pulleys 83 and 84 is disposed at a position where the leading edge of the sheet S sent out by the first conveying means 6 always comes into contact. In this way, the outer peripheral surface of the conveyor belt 82 wound around the outer peripheral surface of the pulley 83 is in direct contact with the outer peripheral surface of the grip roller 81 with a predetermined pressure, and a clamping portion (nip portion) is formed at this contact portion. Has been.
The conveyance belt 82 is formed of, for example, a rubber member that is an elastic member, and the surface thereof is made of a material of the belt itself or subjected to an appropriate surface treatment, and used on a sheet S (sheet) to be used. A predetermined coefficient of friction is set. That is, the conveyance belt 82 faces the sheet S and contacts the sheet surface, and the belt surface as the conveyance surface avoids a sliding contact between the sheet surface and the belt surface, so that the belt surface extends to the sheet surface. A coefficient of friction that can reliably transmit the conveyance driving force is set.

  Further, the conveyance belt 82 has a belt width in the sheet width direction orthogonal to the sheet conveyance direction, which is at least substantially the same as the maximum sheet width to be conveyed. That is, as the belt width of the conveying belt 82, at least a belt width equal to or larger than the maximum sheet width to be conveyed is set and secured. Similarly, the pulleys 83 and 84 on which the conveying belt 82 is stretched and the grip roller 81 facing and contacting the belt have pulleys and roller lengths in the paper width direction (axial longitudinal direction) longer than the belt width. Is formed. Therefore, the sheet S sent out from the first conveying means 6 always comes into contact with the conveying belt 82 over the entire width of the sheet, and the contact area between the two can be ensured as much as possible. Accordingly, the propulsive force supplied to the sheet S from the conveying belt 82 that is always moved in the sheet conveying direction, that is, the conveying propulsive force that advances the sheet S in the conveying direction, also has the maximum possible force from the conveying belt 82. It can be transmitted to the paper S.

  As will be described later with reference to FIGS. 4 and 5, a rotational drive source such as an electric motor provided exclusively for rotational driving of the grip roller 81 is provided on the rotational drive shaft 81 a of the grip roller 81. It is connected via a driving force transmission means such as. The grip roller 81 is rotationally driven by transmitting a rotational driving force at a predetermined rotational speed from the rotational driving source via the driving force transmitting means. Thus, the grip roller 81 is a drive roller, while the conveyor belt 82 in contact with the grip roller 81 and the pulley 83 that supports the contact portion of the conveyor belt 82 from the inside of the belt are grips as a drive roller. A driven belt driven by a belt is driven by the rotation of the roller 81, and a driven roller is driven to rotate through the driven belt. Of course, the pulley 84 is also a driven roller that is rotationally driven via the driven belt.

As shown in FIGS. 4 and 5, the drive mechanism 22 for driving the grip roller 81 and the like is provided with a paper feed motor 23 including a stepping motor as a single drive source / drive means, and an output shaft of the paper feed motor 23. The fixed motor gear 24, the idler gear 25 that meshes with the motor gear 24, the feed roller drive gear 61B that meshes with the idler gear 25 and is fixed to one end of the shaft 61a of the feed roller 61, and the feed roller drive gear 61B A meshing idler gear 26, a grip roller driving gear 81A meshed with the idler gear 26 and fixed to one end of the rotational driving shaft 81a of the grip roller 81, and a feed fixed to the other end of the shaft 61a near the feed roller 61 The roller gear 61A is engaged with the feed roller gear 61A. And idler gear 65 meshes with the idler gear 65, and is mainly composed of a pickup roller gear 60A which is fixed to the other end of the shaft 60a of the pickup roller 60 closer.
The paper feed motor 23 is fixed to the housing 80. The idler gears 25, 26, and 65 are rotatably supported by the housing 80, respectively.
As described above, in this example, the paper conveyance device 5 is compact and space-saving, that is, the first conveyance path A has a radius of curvature as illustrated in Example 1 shown in FIGS. Because of the relatively small curvature portion, the sheet feeding motor 23 is a single unit, which also serves as the driving unit for the first conveying unit 6 and the second conveying unit 7 and contributes to the compactness of the apparatus. is doing.
The reverse roller 62 is driven by a separate system that includes, for example, a solenoid that releases pressure on the feed roller 61 and the like. In FIG. 4, 62b represents what was demonstrated as the torque limiter which is not shown in the example shown in FIGS.

In the example shown in FIGS. 1 to 5, the rotational drive relationship between the pickup roller 60 and the feed roller 61 has been simply described. In practice, however, as shown in an enlarged view in FIG. The shafts 60a and 61a are connected by the pickup arm member 64, and a solenoid (not shown) and the like are arranged so that the pickup roller 60 swings and displaces through the pickup arm member 64 around the shaft 61a on the feed roller 61 side. It is driven by a combination of springs.
In the actual drive mechanism 22, more drive force transmission members such as gears and timing belts are appropriately disposed between the paper feed motor 23 and the feed roller 61, but here the grip roller 81 is a rotation conveyance drive member. In order to clarify that this is the case, an example is shown in both figures.

Here, since the conveyance belt 82 of the belt conveyance means 8 is configured to be brought into direct contact with the grip roller 81 (rotational conveyance drive means / rotational conveyance drive member) that is rotationally driven by the drive mechanism 22, the conveyance belt 82. The variation in the linear velocity of the conveyor belt 82 can be reduced by driving the grip roller 81 side than when driving the side. As a result, the conveyor belt 82 that rotates toward the clamping portion of the second conveyor means 7 is disposed outside (in the outer direction) of the turn of the first conveyor path A (paper transport path), so that the first conveyor path A It is possible to improve the transportability of relatively stiff paper such as thick paper at the turn portion, and by driving the grip roller 81 that faces and directly contacts the transport belt 82 and rotates the transport belt 82, a stable line can be obtained. It becomes possible to convey the sheet to the second conveying means 7 and the subsequent ones at a speed.
This advantage and effect can be easily understood by considering the following technical contents. That is, when the grip roller 81 is driven, the linear velocity of the grip roller 81 is determined only by the outer diameter and the rotational speed of the grip roller 81 itself. On the other hand, considering the case of driving the conveyor belt 82 side, when the conveyor belt 82 is driven, the conveyor belt 82 is driven by a roller-like pulley 83 (belt drive roller, main pulley) provided inside the conveyor belt 82. Is generally driven.
In this case, the linear velocity of the conveyor belt 82 is not limited to the outer diameter and the rotational speed of the pulley 83 provided inside the conveyor belt 82, but varies in the thickness of the conveyor belt 82 due to component variations and the thickness due to wear of the conveyor belt 82. Or the slip between the conveyor belt 82 and the pulley 83. For this reason, it is possible to reduce variations in the linear velocity of the conveyor belt 82 by driving the grip roller 81 side rather than driving the conveyor belt 82 side.
If the effect as described above is not so much desired, for example, the drive system for driving the grip roller 81 is removed from the drive mechanism 22 so that the grip roller 81 is driven and the conveyor belt 82 side is set. You may make it drive with the drive mechanism which is not shown in figure.

2 and 3, reference numeral 70 denotes a conveyance guide member that is provided at a position on the inner side of the sheet conveyance device 5 and has a curved and fixed guide surface 70 a that protrudes substantially downward and contacts the sheet S. Reference numeral 71 denotes a conveyance guide member provided at a position on the outer side of the sheet conveyance device 5. The transport guide member 71 has a guide surface 71 a that is curved and fixed in a concave shape corresponding to the transport guide member 70, and is disposed facing the guide surface 70 a of the transport guide member 70 with a predetermined gap. . Thus, the first conveyance path A is formed between the first conveyance means 6 and the second conveyance means 7 by the conveyance guide member 70, the conveyance guide member 71 and the conveyance belt 82 facing the conveyance guide member 70. Has been.
2 and 3, 72 is a conveyance guide member provided at a position on the outer side of the vertical conveyance path approximately vertically upward from the second conveyance means 7, and 73 is a feed from the paper feed tray 51. This is a conveyance guide member that forms a sheet conveyance path to the nipping portion (nip portion) between the roller 61 and the reverse roller 62 and that has an introduction port for guiding and entering the sheet S in the nip portion. The conveyance guide member 70 is a curved surface that bulges substantially downward (on the conveyance guide member 71 side provided on the outer wall) across the line connecting the nip portions of the first conveyance means 6 and the second conveyance means 7. (Guide surface 70a) is provided, and the degree of bulge is set such that the sheet S is gently curved so that the leading edge of the sheet S always reaches the belt conveyance surface.

  In FIG. 1, the upper apparatus configuration of the sheet feeding device 3 is an apparatus configured by conventional means. Compared with the lower apparatus configuration described above, the sheet conveyance apparatus 5 ′ replaced with the sheet conveyance apparatus 5. The only difference is the use of. The sheet conveying apparatus 5 ′ is different from the sheet conveying apparatus 5 only in that the second conveying means 7 ′ is used instead of the second conveying means 7. Compared with the second conveyance means 7, the second conveyance means 7 ′ has a grip roller 81 as a second conveyance rotation member pair and a roller that is driven and rotated (substantially the same size and shape as the pulley 83). Only) is different. In the upper paper feed tray 51 and the paper transport device 5 ′, plain paper or the like, which is the paper S having relatively low rigidity, is used except for the paper S (sheet) having relatively high rigidity such as thick paper and envelopes.

Next, a paper feeding operation from a predetermined stage in the paper feeding device 3 and a transporting operation of the paper transporting device 5 started in conjunction with the paper feeding operation will be described.
As shown in FIG. 2, the sheets S stacked on the bottom plate 50 are lifted so that the uppermost surface thereof has a predetermined height by the swinging and lifting operation of the lifting arm 52. The uppermost sheet S is pulled out and conveyed to a sheet feeding / separating mechanism including a feed roller 61 and a reverse roller 62. In the sheet feeding / separating mechanism, only the uppermost sheet is separated by the cooperative action of the feed roller 61 and the reverse roller 62, and the separated sheet S is moved to the downstream side of the sheet conveying path. Further, as shown in FIG. 2, the leading edge of the sheet S is guided and moved by traveling in the direction of the arrow of the conveyance belt 82 while contacting the belt conveyance surface of the conveyance belt 82, and the grip roller 81 and the conveyance belt 82 are moved. When reaching the nip portion, the sheet S is conveyed by being vertically conveyed while being nipped and conveyed by the grip roller 81 and the conveying belt 82, and finally the sheet S is sent out in a vertical posture.

More specifically, the leading edge of the sheet S that is nipped between the feed roller 61 and the reverse roller 62 and fed out from the nip portion first reaches the belt conveyance surface of the conveyance belt 82 as shown in FIG. And touch. Then, as shown in FIG. 3, the conveyance surface 82a is gradually curved from the leading end side of the sheet S as the conveyance surface 82a moves in the direction of the sheet conveyance due to the traveling of the conveyance belt 82 in the direction of arrow a, and this curve progresses. Accordingly, the contact area between the belt conveyance surface and the paper surface is enlarged. Therefore, even if the paper S is a highly rigid paper, a sufficient transport driving force for advancing the paper S in the transport direction from the belt transport surface to the paper surface can be applied. In this way, the belt conveyance means 8 provides a shortage from the conveyance resistance generated when the highly rigid paper S is curved and conveyed more deeply by the conveyance driving force applied from the first conveyance means 6. Give it to the paper S to make up for it. Therefore, it is possible to prevent at least the occurrence of poor conveyance of the paper S between the first and second conveying means 6 and 7 and prevent the paper S from occurring. Nip).
On the other hand, the conveyance surface 82a of the conveyance belt 81 extends continuously as it is to the nipping portion (nip portion) of the second conveyance means 7, so that the leading edge of the sheet S in contact with the belt conveyance surface is reliably and smoothly stabilized. Then, it reaches the clamping part. In other words, first, even the highly rigid paper S is conveyed by the first conveying means 6 while being gently curved so that the leading edge always comes into contact with the belt conveying surface, and the leading edge of the paper S is the belt conveying surface. The leading edge of the sheet S is moved to the second sheet after the second sheet conveying propulsion force that advances in the sheet conveying direction from the belt conveying surface to the sheet S by the active conveying guide action by the belt conveying surface. The sheet S is bent more deeply so as to reach the holding portion of the conveying means 7.

  After the leading edge of the paper S reaches the second transport means 7 and the paper S is nipped and transported by the first transport means 6 and the second transport means 7, the transport means 6 and 7 are sufficient. Since a strong transport force acts on the paper S, the smooth transport of the highly rigid paper S can be continued. Further, even if the rear end of the sheet S is detached from the first conveying unit 6 and the conveying force from the first conveying unit 6 cannot be obtained, the holding portion of the second conveying unit 7 on the sheet S is moved to the rear end side. Depending on the contact state of the belt conveyance surface, the conveyance driving force is replenished from the belt conveyance surface to the paper surface again, and the degree of curvature of the paper S is gradually reduced, so that the paper conveyance can be continued. it can. As a result, as the paper transport device 5, the paper S received by the first transport means 6 is reliably and stably transferred from the second transport means 7 to the downstream paper transport path regardless of the rigidity of the paper S. Can be sent out.

As described above, the belt conveyance unit 8 is disposed in the outer direction of the first conveyance path A formed between the first conveyance unit 6 and the second conveyance unit 7 and maintains a state in contact with the leading edge of the paper S. However, it has a function as a movement guide means for moving and guiding the paper S toward the second transport means 7.
In this example, the belt conveying means 8 as the movement guiding means moves and guides the conveying direction of the sheet S in the direction toward the nipping portion (nip portion) of the second conveying means 7 by the conveying belt 82. It also has a function.

  Next, Reference Example 1 (hereinafter simply referred to as “Example 1”) according to the invention of the prior application will be described. The basic configuration and specifications are the same as those of the paper feeding device 3 having the paper conveying device 5 shown in FIGS. 1 to 5, and only a paper feeding device of “Imagio Neo453” manufactured by Ricoh Co., Ltd. has been modified for testing. Machine (shown as “belt system” in Table 1) and a conventional paper conveying device (in FIGS. 1 to 5, the conveying rotating member that faces and contacts the grip roller 81 is a roller-like pulley 83, and the conveying belt 82 and "Imagio" manufactured by Ricoh Co., Ltd., which is equipped with a paper feeder provided with a roller-like pulley 84 and having a paper feed device 5 'shown in the paper feeder 3 shown in FIG. Using a Neo453 "copying machine (shown as" conventional system "in Table 1), a comparative test on the paper feeding and conveying state (paper passing state) was conducted.

In the belt system, details of the belt conveying means 8 used in the comparative test and the main members around it (including the conventional system) are as follows.
Material of conveyor belt 82: Ethylene / propylene rubber (EPDM)
Conveyance belt 82 hardness: JIS A 40 degrees Friction coefficient of conveyance belt 82: 2.6 (for paper)
Conveying belt 82 wall thickness: 1.5 mm
Pulley 83 diameter: 13 mm
Pulley 84 diameter: 7 mm
Spacing between pulleys 83 and 84: 13 mm (distance between pulley shafts 83a and 84a)
Expansion rate of the conveyor belt 82: 7%
Diameter of each roller 60, 61, 62, 81: All 20mm

As a basic test condition, the weight of the paper (metric basis weight ) is used as a substitute value for the strength of the paper (stiffness: stiffness). At a relative humidity of 50%, the sheets were fed from the same tray in the copying machine. Then, with the test conditions described below with reference to FIG. 6, a test for examining the variation (variation) in the conveyance time of each paper type was performed. FIG. 7 shows a test result of the variation in the conveyance time, and Table 1 shows a summary of the sheet passing state based on the test result of FIG.

  In FIG. 6, 88 is a paper feed sensor that detects the leading edge of the paper S picked up by the pick-up roller 60, and 89 is a second conveying means 7 (belt type) or a grip roller 81 and a roller-like pulley 83. A vertical conveyance sensor for detecting the leading edge of a sheet conveyed by a pair (conventional method) is shown. The paper feed sensor 88 and the vertical conveyance sensor 89 are each composed of a reflective photosensor.

Further, the conveyance path length between the attachment / arrangement of the paper feed sensor 88 and the vertical conveyance sensor 89: the sheet conveyance distance (sheet conveyance distance) was set to a constant 57 mm for both the belt method and the conventional method as follows. That is, the conveyance path length from the arrangement portion of the paper feed sensor 88 to the nip portion of the feed roller 61 and the reverse roller 62 is 10 mm, and the nip portion of the second conveyance means 7 from the nip portion of the feed roller 61 and the reverse roller 62 ( Belt path), or the conveyance path length from the nip portion between the feed roller 61 and the reverse roller 62 to the nip portion between the grip roller 81 and the roller pulley 83 (conventional method) is the same 38 mm, The conveyance path length from the nip part (belt system) to the arrangement part of the vertical conveyance sensor 89 or from the nip part (conventional system) between the grip roller 81 and the roller pulley 83 to the arrangement part of the vertical conveyance sensor 89 is 9 mm. The total transport path length is 57 mm.
The radius of curvature at the center of the curved paper conveyance path (first conveyance path A) between the first conveyance means 6 and the second conveyance means 7 of the paper conveyance device 5 is constant about 20 mm in both the conventional method and the belt method. Carried out.

  In both the conventional method and the belt method, the pick-up pressure (feed pressure) by the pick-up roller 60 is changed to two types of 1.1N and 2.2N, and the driving-side feed roller 61 and the driving-side grip are changed. Both the linear speeds of the rollers 81 are the same 154 mm / s, and the arrival time of the leading edge of the paper transported through the transport path length 57 mm from the paper feed sensor 88 to the vertical transport sensor 89 is changed to five paper types, respectively. The graph of FIG. 7 shows the variation result of the paper type conveyance time measured by the oscilloscope.

From the test results of FIG. 7, when the metric basis weight is 256 g / m ² or more as the paper type, the conveyance time is long in the conventional method and the slip of the paper is large. It turned out that the slip of the paper was small without becoming long. Further, it was found that the conveyance force decreases when the pickup pressure is reduced, but in the case of the belt system of the present invention, even if the pickup pressure is reduced, the conveyance time is not significantly affected. Therefore, when the belt system of the present invention is adopted, the pickup pressure can be reduced, so that the power of the drive motor can be reduced. As a result, the apparatus can be reduced in size.

Next, Table 1 that summarizes the sheet passing state based on the test results of FIG. 7 will be described.
Here, “metric basis weight ” corresponds to the weight of one sheet of paper per square meter in grams when displaying the weight of paper or paperboard (paper). In general, a paper having a small basis weight is “light paper” or “thin paper”, and a paper having a large basis weight is “heavy paper” or “thick paper”.
In the test results in Table 1, “good paper passing” indicated by a circle indicates that the paper feed sensor 88 was turned on and reached the vertical conveyance sensor 89 within a predetermined time after the leading edge of the paper (sheet) was detected. That is, “impossible to pass paper” indicated by a cross indicates that the conveyance is good means that the vertical conveyance sensor 89 is reached within a predetermined time after the paper feed sensor 88 is turned on and the leading edge of the paper is detected. This indicates that there was no conveyance, that is, a conveyance failure.

From the test results in Table 1, when the metric basis weight is 256 g / m ² or more as the paper type, the conventional method could not pass the paper, whereas the belt method according to the present invention shown in FIGS. All the papers passed. Thereby, the remarkable effect of the belt system according to the present invention was recognized.
According to the comparative observation of the sheet passing / conveying state, when the metric basis weight is 256 g / m ² or more in the conventional method, the sheet becomes stiff and difficult to bend along the curved sheet conveying path. 1 to 6, it was found that the leading edge of the sheet hits a roller-like pulley 83 that faces and contacts the grip roller 81.
In addition, as a paper type, a paper having a metric basis weight of 256 g / m ² or more was subjected to a comparative observation of a sheet passing / conveying state using a paper whose surface portion was coated and a paper which was not coated. However, significant differences other than the test results in Table 1 were not recognized.

From the observation results of the paper conveyance process in Example 1 described above, the following was found. That is, when the highly rigid paper S having a metric basis weight of 256 g / m ² or more is transported from the first transport unit 6 to the transport surface 82a of the transport belt 82 in the belt transport unit 8 via the first transport path A. Because of the high straightness transportability of the highly rigid paper S, the various guide members constituting the first transport path A are changed to simple shapes that reduce the transport load resistance or the various guide members are changed. It turns out that it is possible to make it completely unnecessary.
Therefore, in the case of a sheet conveying apparatus that conveys using only the sheet S having relatively high rigidity, the essential components are the first conveying means 6, the second conveying means 7, the first and The second transport unit is disposed in the outer direction of the first transport path A (in this case, no guide member is formed) formed between the second transport units 6 and 7 and maintains a state in contact with the leading edge of the sheet S. Belt conveying means 8 (movement guiding means) for moving and guiding the paper S toward the paper 7.
From the above, the various guide members forming the first transport path A have relatively low rigidity, for example, when the paper S such as plain paper or PPC is transported, the straightness of the paper S with low rigidity is weak. It can be said that it is necessary to compensate for the straightness as compared with the paper S having relatively high rigidity such as thick paper, and to guide and guide it to the transport surface 82a of the transport belt 82. In other words, the first transport path is used in order to make the leading edge of the paper S abut on the antinode portion of the transport surface 82a of the transport belt 82 to compensate for the decrease in straightness as the rigidity of the paper S decreases. It can be said that it is necessary to set the shape of the guide surfaces of the various guide members forming A.
In other words, as the sheet S having higher rigidity (the sheet S having a larger metric basis weight ) is used, the various guides used when configuring the sheet conveyance path of the curvature portion having the relatively small curvature radius described above. It becomes possible to give a degree of freedom to the design of the shape and arrangement of the members.
The material of the conveyor belt 82 is not limited to that used in the comparative test, and may be, for example, chloroprene rubber, urethane rubber, or silicon rubber. The rubber hardness of the conveyor belt 82 may be JIS A 40-60 degrees.

  As described above, according to the paper conveyance device 5 and the copying machine 1 having the same shown in FIGS. 1 to 6, the paper type compatibility is achieved with a simple and low-cost device configuration while being compact and space-saving. It is possible to provide a sheet conveying apparatus and an image forming apparatus excellent in the above. In other words, basically, the conveyor belt is wound around the existing roller that constitutes the second conveying means, and the belt conveying means 8 is newly provided and added, and a dedicated drive source for the belt conveying means 8 is also provided. The sheet conveying device and the image forming apparatus can be realized at a low cost because of the extremely simple configuration.

  In the conventional configuration, the conveyance resistance due to the contact of the sheet with the conveyance guide member 70 is large, or the rigidity is high due to the conveyance load in the first conveyance path A from the first conveyance unit 6 to the second conveyance unit 7. In contrast to the paper type, which causes a conveyance failure, the paper conveyance device 5 can cope with a high-rigidity paper type and is a paper conveyance device with excellent paper type characteristics. That is, in the conventional configuration, since the fixing member is merely arranged for guiding the paper, the speed difference between the transported paper that is a moving body and the fixed guide member is fundamentally different. The sheet conveyance device 5 and the copying machine 1 not only eliminates the conveyance resistance but always eliminates the conveyance resistance and positively advances the sheet downstream. It is possible to guide while applying a conveyance driving force (or, by adding a conveyance force by the second conveyance means 7 to a conveyance force by the first conveyance means 6, the first conveyance means 6 to the second conveyance means 7 Since it is possible to counter the transport load in the first transport path A, the sheet can be advanced downstream). That is, in the paper transport device 5, the frictional resistance generated between the paper S and the transport belt 82 is not a resistance that hinders the transport of the paper S, but a negative resistance for applying a transport driving force to the paper S. Become. In other words, it is not converted to a resistance that acts to prevent the conveyance of the paper S, but is converted to a preferable negative resistance that acts to give a conveyance driving force to the paper S.

In addition, in the transport direction in which the paper S is transported, after the leading edge of the paper S abuts the running surface (transport surface) of the transport belt 82, the difference in the degree of rigidity depending on the paper type as the transport progresses. However, since the leading end surface of the sheet S is conveyed so as to gradually overlap the traveling surface of the conveying belt 82, the area of the sheet surface in contact with the belt traveling surface gradually increases. For this reason, as the contact area increases, the resistance force between the two can be increased, and a larger transport driving force for advancing the paper S in the transport direction can be supplied from the transport belt 82 to the paper S. As a result, the traveling direction of the sheet S is changed toward the nip portion between the grip roller 81 and the conveyance belt 82. In other words, the force acting as the conveyance driving force transmitted from the running surface (conveyance surface) of the conveyance belt 82 to the sheet surface is steadily increased.
Therefore, even if the rigidity of the sheet S is high, the sheet S is surely directed toward the sandwiching portion of the second transporting means while overcoming this rigidity and appropriately deforming or curving the sheet S in the thickness direction. In addition, it can be transported stably. As described above, since the main cause of the conveyance failure due to the high rigidity of the sheet S can be dealt with, the sheet conveyance after the leading edge of the sheet S reaches the clamping portion of the second conveying means is reliably and stably performed. It can last. As a result, the paper transport device can cope with a wide variety of paper types, the transport capability can be expanded, and high paper transport performance can be obtained.

(Second example)
A second example to which the invention of the prior application is applied will be described with reference to FIGS. The same components and members as those of the sheet conveying device 5 shown in FIGS. 1 to 6 are denoted by the same reference numerals, and the description thereof is omitted or simplified. Although not particularly described, the configuration not described in this example, that is, the sheet conveying apparatus and other configurations and the operation thereof are the same as those of the sheet conveying apparatus 5 of the first example and the first embodiment shown in FIGS. is there.

  The paper transport device 5 shown in FIGS. 8 to 10 is first formed between the first transport device 6 and the second transport device 7 as compared with the paper transport device 5 shown in FIGS. In addition to the first conveyance path A serving as the sheet conveyance path, another independent second sheet conveyance path formed from the upstream of the second conveyance means 7 to the second conveyance means 7 and different from the first conveyance path A The point having the second transport path B as the first, the first transport path A and the second transport path B merge at the upstream of the second transport means 7 (hereinafter referred to as “joining transport path” or “joining section”) And the other belt conveying means 8 of the second conveyance rotating member pair is disposed so as to be out of the outline direction of the merged conveyance path of the first and second conveyance paths A and B. Mainly different. The sheet conveying apparatus 5 shown in FIGS. 8 to 10 is the same as the sheet conveying apparatus 5 shown in FIGS. 1 to 6 except for the differences.

  In other words, the belt conveying means 8 is configured such that one of the pair of roller-like pulleys 83, 84 around which the conveying belt 82 is stretched is separated from the pulley 83 by a predetermined distance to be freely rotatable to the housing 80. As a result, the belt conveyance surface is formed as a surface in the outline direction of the second conveyance path B. Therefore, the leading surface of the sheet S conveyed on the first conveying path A by the first conveying means 6 always comes into contact with the conveying surface 82a of the conveying belt 82, and on the second conveying path B by an unillustrated conveying means. This prevents the conveyed paper S from reaching the second transport means 7.

Next, the conveying operation of the sheet conveying device 5 shown in FIGS. 8 to 10 will be described. Since the paper S is fed out and transported from the state of being horizontally stacked in the paper feed tray 51, the paper transport direction in the paper feed separation mechanism of the first transport means 6 is substantially horizontal, but thereafter it is positioned upward. In order to convey the image forming apparatus main body 2 to the image forming unit, it is necessary to convey the sheet S in a substantially vertical upward direction orthogonal to the substantially horizontal direction.
Therefore, as shown in FIG. 9, after separation of the sheets S one by one by the sheet feeding / separating mechanism, one sheet S is conveyed with a gentle bend so that the conveyance resistance is small, and the leading end thereof is a conveyance belt. 82 abuts.
Since the conveyor belt 82 is traveling so as to travel in a substantially vertical upward (substantially upward) direction indicated by an arrow a in FIG. 9, the leading edge of the sheet S in contact with the conveyor belt 82 is illustrated in FIG. As shown in FIG. 10, it is conveyed to the clamping part (nip part) between the grip roller 81 and the conveyor belt 82, and is clamped and conveyed downstream in the substantially vertical upward direction by the pair of the grip roller 81 and the conveyor belt 82. . At this time, as described above, the sheet S is subjected to the conveyance propulsion force that is transmitted from the conveyance belt 82 in the conveyance direction and acts toward the nip portion between the grip roller 81 and the conveyance belt 82 by the conveyance belt 82. Therefore, even the highly rigid paper S can be stably conveyed without causing a conveyance failure.

  As described above, according to the paper conveyance device 5 shown in FIGS. 8 to 10, the paper conveyance device having the merging conveyance path is the same as the paper conveyance device 5 described with reference to FIGS. 1 to 6. Effects, that is, high-stiffness paper such as cardboard can be stably conveyed, has excellent paper type compatibility, and has at least two or more conveyance paths such as first and second conveyance paths A and B. The paper conveying apparatus can be applied in correspondence with the developed paper conveying apparatus, and the application range can be expanded, that is, the paper conveying apparatus excellent in model compatibility can be obtained.

(First embodiment)
With reference to FIG. 11 to FIG. 14, the sheet conveying device 5 </ b> A of the first embodiment will be described. The sheet conveying apparatus 5A according to the first embodiment shown in FIGS. 11 to 14 is different from the sheet conveying apparatus 5 of the second example shown in FIGS. Instead of the drive mechanism 22 having one paper feed motor 23, the pickup roller 60 and the feed roller 61 of the first conveying means 6 are rotated at a first linear velocity (hereinafter also referred to as “linear velocity before turn”). The first conveying motor 29 as the first conveying driving unit to be driven and the rotation of the grip roller 81 of the first conveying unit 7 drive the conveying belt 82 to the second linear velocity (hereinafter referred to as “belt linear velocity”). As a first linear velocity detecting means for detecting the first linear velocity (linear velocity before turn), which is a driving mechanism using the second conveying motor 30 as the second conveying driving device to be driven and rotated in the The point that the paper linear velocity detection sensor 39 is attached, The belt linear speed detection sensor 40 as the second linear speed detection means for detecting the linear speed (belt linear speed) of the belt, the output signal from the paper linear speed detection sensor 39, the belt linear speed detection sensor 40, etc. Based on this, the main difference is that a control device 43 is used as a control means for controlling the first transport motor 29 and the second transport motor 30 as described later.
The greatest feature of the sheet conveying device 5A of the present embodiment is that the control device 43 makes either one of the linear velocity before the turn and the belt linear velocity relatively variable, in other words, the control device 43 makes the turn front The relative speed of the belt speed and the belt linear speed is changed.

Therefore, with reference to FIG. 13, the necessity of changing the relative speed of the first linear speed (linear speed before turn) and the second linear speed (belt linear speed) will be described.
First, as shown in FIGS. 13A to 13C, the first conveyance path A (hereinafter also referred to as “turn part”) having a small radius of curvature shown in FIGS. When considering the behavior of the leading end of the sheet when the sheet S enters the conveying surface 82a of the conveying belt 82 with the rushing angle θa, the sheet S having relatively high rigidity such as thick paper (for example, the above-described embodiment) The tip Sf of a metric basis weight of 1 (such as a paper type such as 256 g / m ² or 300 g / m ² ) enters at an inclined angle by an angle of bending at the turn portion with respect to the conveyance surface 82a of the conveyance belt 82. Therefore, the leading edge Sf of the paper S is apparently more than the rear part of the paper S by the amount that the conveyance guide member 71 (not shown in FIG. 13, see FIG. 9 or the like) advances while being bent by the waist of the paper in the direction after the turn. (Fig. 3 (c), ( d)).

13 through the transfer of the turn portion relatively rigid sheet S such as thick paper, as shown in (a) is in turn front speed v _1, the tip Sf of the sheet S as shown in FIG. 13 (b) conveying When abutting and abutting against the conveying surface 82a of the belt 82 with a rushing angle θa, as shown by a broken line in FIG. 13C, the abutting of the leading end Sf of a sheet S such as plain paper having a relatively low rigidity. In the case of the case, in the state of being elastically buckled, it is bent along the downstream side of the transfer surface 82a. As a result, the position of the leading edge Sf of the paper S that comes into contact with and contact with the conveyance belt 82 is different, and there is a difference in the distance traveled by the conveyance belt 82 per unit time.
That is, as shown in FIG. 13 (d), the relatively high rigidity sheet S such as thick paper that has been conveyed by the turn front speed v ₁ at the tip Sf the conveyor belt 82 of the sheet S after being in contact abutment, those _'When the tip of the relatively rigid sheet S such as thick paper Sf linear velocity v ₁ of the distal end _Sf' linear velocity v ₁ of the tip Sf shown in broken lines in turn front speed v _{1 (FIG.} 13 (d) It becomes that go ahead only on the downstream side of the running direction a of the conveyor belt 82 the difference between the magnitude of the vector with the relatively low rigidity such as plain paper is also the turn-front speed v ₁ of the tip Sf of the sheet S in) The apparent linear speed (conveyance speed) is fast. This phenomenon is because the conveying belt 82 is made of rubber and the coefficient of friction with respect to the paper S is set large, so that the holding force of the leading edge Sf of the paper S having relatively high rigidity such as thick paper is particularly large. It is considered that it is transported without causing slip or the like because it works effectively.

Therefore, in order not to cause problems such as turning over at the leading end Sf of the sheet S having relatively high rigidity such as thick paper, the belt conveying unit 8 that conveys the leading end Sf of the sheet S (the second conveying unit 7 from the above configuration). Also, a speed higher than the pre-turn linear speed v ₁ (first linear speed) of the first conveying means 6 is required. On the other hand, the leading edge Sf of the paper S is sandwiched by a nip portion (not shown in FIG. 13; see FIG. 9, etc.) guided by the conveyor belt 82 and formed by the grip roller 81 and the conveyor belt 82 in the second conveyor means 7. After this, the linear velocity at the leading edge Sf and the trailing edge of the paper S becomes equal, so the belt linear velocity (second linear velocity) may be the same as the linear velocity before turning (first linear velocity). In this case, if the belt linear velocity is increased, other problems such as rubbing may occur. Therefore, in the case of transporting the relatively high-stiff sheet S such as thick paper, the relative speed of the belt 82 of the transport belt 82 (second linear speed) and the linear speed before the turn of the first transport means 6 (first linear speed). By changing the speed with the progress of the paper S, the leading edge Sf of the paper S can be transported without causing problems such as turning over the transport belt 82. The present embodiment is made based on such a basic principle (hereinafter the same).

With reference to FIG. 12, the control configuration around the sheet conveying device 5A of the present embodiment will be described in detail. The control configuration shown in FIG. 12 is basically the same in the later-described embodiments and modified examples, and a part of the control function of the CPU 44 in the control device 43, the operation program stored in the ROM 45, etc., the related data, etc. It is only different.
As described above, in the present embodiment, the relative speed of the belt linear velocity (second linear velocity) of the conveyance belt 82 and the linear velocity before turning (first linear velocity) of the first conveyance means 6 is determined as the sheet S advances. Since control to change is necessary, it is not easy to perform these controls with only the single paper feed motor 23 shown in FIG. Therefore, in the present embodiment, in order to facilitate and understand the variable control of the relative speed, two first and second transport motors 29 and 30 are provided, and the first and second linear velocities that are independent of each other. It was decided to control (which is also the peripheral speed or the conveyance speed).
The first transport motor 29 is connected to the shaft 61a of the feed roller 61 and the shaft 60a of the pickup roller 60 via driving force transmission means such as a gear train, and rotationally drives the feed roller 61 and the pickup roller 60. The second transport motor 30 is also connected to a rotational drive shaft 81a of the grip roller 81 via a driving force transmission means such as a gear train, and rotationally drives the grip roller 81 and rotates the transport belt 82. The first and second transport motors 29 and 30 are stepping motors that are easy to change the rotation speed, easy to control, and are small and relatively inexpensive.

The sheet linear velocity detection sensor 39 is provided in a groove portion (not shown) of the conveyance guide member 71 so as not to hinder the conveyance of the sheet S.
The belt linear velocity detection sensor 40 is provided in the vicinity of the outer periphery of the conveyance belt 82 facing the lower pulley 84 and is a sensor for detecting the second linear velocity (belt linear velocity) of the conveyance belt 82. . The sheet linear velocity detection sensor 39 and the belt linear velocity detection sensor 40 are sensors such as laser Doppler and laser speckle.

The sheet linear velocity detection sensor 39 is not limited to the above sensor, and may be a reflective photosensor that detects the leading edge of the sheet S. In this case, when the pickup roller 60 starts to rotate, the uppermost sheet S on the bottom plate 50 is fed out to reach the sheet linear velocity detection sensor 39 via the rotational drive of the first conveying means 6, and the pickup roller 60. The first linear velocity (linear velocity before turn) is obtained from the calculation of the CPU 44 in the control device 43 from the constant conveyance distance of the paper S from the contact position of the paper S on the outer peripheral surface to the paper linear velocity detection sensor 39. be able to.
The belt linear velocity detection sensor 40 is not limited to the above sensor, and may detect the second linear velocity (belt linear velocity) by using a photo rotary encoder or the like for the upper pulley 83. In this case, the photo rotary encoder / sensor detects the number of light pulses per unit time of the photo rotary encoder that rotates together with the upper pulley 83 to generate an output signal. The second linear velocity (belt linear velocity) can be known by the calculation of the CPU 44.

  In FIG. 12, the control device 43 includes a relative speed between the linear velocity before the turn (first linear velocity) and the belt linear velocity (second linear velocity) of the sheet conveying device 5 </ b> A, including later-described embodiments and modifications. This is for performing change control and the like. In the following, for the sake of simplicity of explanation, a main control device as main control means (not shown) that controls the overall operation of the copying machine 1 except for the control of the paper transport device 5A and the like of the paper feeding device 3 shown in FIG. The main control device and the control device 43 will be described as transmitting and receiving a command signal, an on / off signal, a data signal, and the like. The main control device and the control device 43 are provided, for example, on a control board (not shown) on the image forming apparatus main body 2 side shown in FIG. When the sheet feeding device 3 is a unit of movement as a product form, the control device 43 may be provided on the main body side of the sheet feeding device 3.

The control device 43 includes a CPU (central processing unit) 44, an I / O (input / output) port (not shown), a ROM (read only storage device) 45, a RAM (read / write storage device) 46, a timer (not shown), and the like. And a microcomputer having a configuration in which they are connected by a signal bus.
The CPU 44 is connected to the start switch and various keys (not shown) of the operation panel 95 as an operation unit, the paper linear velocity detection sensor 39, and the belt linear velocity detection sensor 40 via the input port and each sensor input circuit. Electrically connected.

On the operation panel 95, as various keys, a numeric keypad (not shown) for setting and setting the number of sheets S to be fed and the like, and a paper feed stage in which relatively stiff paper such as cardboard is stored. Normal / other than high-rigidity paper (high-rigidity sheet) selection key (not shown) for selecting / setting (feed tray 51 and paper-conveying device 5A) and generating a signal for feeding and conveying the paper S Ordinarily, a paper feed stage (paper feed tray 51 and paper transport device) that stores paper with relatively low rigidity such as paper and thin paper is selected and set, and a signal for driving the paper S to be fed and transported is generated. A paper selection key, a thin paper selection key (both not shown), and the like are provided.
Based on an output signal from the high-rigidity paper selection key provided on the operation panel 95, the CPU 44 uses, for example, a cardboard having a metric basis weight of 256 to 300 g / m ² as described in the first embodiment. The sheet feeding device 51 has a function of starting and controlling each driving unit so as to feed and convey the sheet S from the sheet feed tray 51 of the sheet feed stage in which the sheet S having relatively high rigidity is stored. Since the following embodiments and modifications including this embodiment all relate to control when feeding and transporting a relatively rigid paper S, “the CPU 44 is disposed on the operation panel 95. Based on the output signal from the high-rigidity paper selection key, a paper S having a relatively high rigidity such as a thick paper having a metric basis weight of 256 to 300 g / m ² as described in the first embodiment is used. The description of “starting control of the sheet conveying device 5A so that the sheet S is fed and conveyed from the sheet feeding tray 51 of the housed sheet feeding stage” will be omitted.

The CPU 44 has a calculation function that finally obtains the line speed before the turn by calculation based on the output signal (data signal) related to the line speed before the turn from the sheet linear speed detection sensor 39. Similarly, the CPU 44 also has a calculation function for finally obtaining the belt linear velocity by calculation based on an output signal (data signal) relating to the belt linear velocity from the belt linear velocity detection sensor 40. Further, the CPU 44 determines the arrival time at which the leading edge of the sheet S contacts the conveying surface 82 a of the conveying belt 82, as a predetermined time of the preset sheet S from the sheet linear velocity detection sensor 39 to the conveying surface 82 a of the conveying belt 82. It also has a calculation function for calculating from the transport distance and the calculated line speed before turn. Further, the CPU 44 determines the time when the leading edge of the sheet S starts to be nipped and conveyed by the nip portion of the second conveying means 7 from the position where the leading edge of the sheet contacts the conveying surface 82a of the conveying belt 82. It also has a calculation function for calculating from a predetermined transport distance of the paper S set in advance to the section and the obtained belt linear velocity.
The CPU 44 is electrically connected to the first transport motor 29 and the second transport motor 30 via the output port and a motor drive circuit (not shown), and a command signal for driving and controlling these motors 29 and 30. Is transmitted to each of the motor drive circuits.

The RAM 46 temporarily stores the calculation results of the CPU 44, and stores output signals from the high-rigidity paper selection key of the operation panel 95, the paper linear speed detection sensor 39, and the belt linear speed detection sensor 40 as needed. Input / output these signals.
In the ROM 45, “related data on the number of pulses supplied to the first transport motor 29 and the second transport motor 30 via each motor drive circuit (not shown)” for the CPU 44 to perform a control function to be described later, “not shown. Data related to the frequency of pulses supplied to the first conveyance motor 29 or the second conveyance motor 30 for changing the first or second linear velocity (linear velocity before turn or belt linear velocity) via each motor drive circuit " Or “a program for changing the first or second linear velocity (the linear velocity before the turn or the belt linear velocity) shown in each figure”, or “related data relating to relational expressions and conditional expressions described later”, etc. It is remembered. The timer has a function as time measuring means for measuring time.

FIG. 14 shows changes in the belt linear velocity according to this embodiment. Details thereof will be described later. In the linear velocity diagram shown in each figure to be described later with reference to FIG. 14, the horizontal axis represents time t (s), and the vertical axis represents linear velocity v (mm / s). In addition, v ₁ indicated by a thin solid line is the linear velocity before the turn (first linear velocity), v ₂ indicated by a thick solid line is the belt linear velocity (second linear velocity), and t ₁ is the leading edge of the paper S being the conveying belt. The time when the front surface of the sheet S starts to be nipped and conveyed by the nip portion of the second conveying means 7 is indicated by t ₂ (hereinafter, the same applies).

In the present embodiment, the CPU 44 of the control device 43 has the following control functions. The CPU 44, based on the output signal related to the front linear speed from the sheet linear speed detection sensor 39 and the output signal related to the belt linear speed from the belt linear speed detection sensor 40, the front linear speed v ₁ and the belt linear speed shown in FIG. v ₂ , time t ₁ , t ₂ are appropriately calculated and obtained, and the front of the sheet S transported by the first transport unit 6 is contacted with the transport surface 82 a of the transport belt 82 while referring to them appropriately. The belt linear velocity v ₂ is higher than the linear velocity v ₁ before the turn (belt linear velocity v ₂ ) after the contact and before it is nipped and conveyed by the nip portion (nip portion) of the second conveying means 7. > Linear speed v ₁ ) Before the sheet S is conveyed at the front-turn linear velocity v ₁ ) and the leading edge of the sheet S begins to be nipped and conveyed by the nip portion of the second conveying means 7, the belt linear velocity v ₂ becomes the linear velocity V ₁ before the turn. Equal linear velocity (belt wire v 2 ₌ to convey the sheet S in turn front speed v _1), having a basic first control function of controlling the first conveyance motor 29 and the second conveyance motor 30.
In addition to the first control function, the CPU 44 uses the nip portion of the second conveying unit 7 from the time when the leading edge of the paper S conveyed by the first conveying unit 6 contacts the conveying surface 82a of the conveying belt 82. Before starting to be sandwiched and transported, the first transport motor 29 is controlled so that the pre-turn linear velocity v ₁ is constant, and at least until immediately before the gripping and transport is started by the nip portion of the second transport means 7 a second control function of the belt linear velocity v ₂ controls the second conveying motor 30 to be equal to the turn-front speed v ₁ is switched to deceleration instantly.

The change of the linear velocity before the turn (first linear velocity) or the belt linear velocity (second linear velocity) is determined by the frequency of pulses (pps: pulse) supplied to the first conveyance motor 29 or the second conveyance motor 30 by the control device 43. per second), that is, by changing the pulse interval (acceleration / acceleration if the pulse interval is narrowed, constant speed at a constant interval, and deceleration if the pulse interval is increased). In this linear velocity changing method, the linear velocity can be instantaneously accelerated / accelerated or decelerated, or gradually or gradually (gradually) accelerated / accelerated or decelerated. In addition, in FIG. 15 and the like to be described later including FIG. 14, the linear velocity deceleration and switching changes that are decelerated or increased are easy to understand and somewhat exaggerated / simplified, that is, the constant linear velocity v ₁ before turn and the belt linear velocity. v ₂ represents to raise falling or falling standing vertical manner with respect to it, and switching of deceleration and speed increasing of substantially trapezoidal shape with an inclination angle in practice.

As shown in FIG. 14, in this embodiment, the leading end of the sheet S is belt linear velocity v ₂ before passing through the first conveying unit 6 is controlled to be faster than the turn fronts speed v ₁ . After time t _{1 when the} sheet S is further conveyed and passes through the first conveying unit 6 and the leading end of the sheet S comes into contact with the conveying surface 82a of the conveying belt 82, the leading end of the sheet S becomes the nip portion of the second conveying unit 7. in in a sandwich-transported faster timing than the time t ₂ is the belt linear velocity v ₂ is switched to be decelerated immediately becomes equal to the turn-front speed v _1.
Note that regarding the specific set speed of the pre-turn linear velocity v1 before the leading edge of the sheet S passes through the first conveying unit 6, the leading edge of the second and subsequent sheets S is conveyed first. Of course, the speed is appropriately set so as to maintain an appropriate inter-paper distance (sheet-to-sheet distance) that does not contact the trailing edge of the paper S (the same applies hereinafter).

  As described above, according to the present embodiment, first, the belt linear speed of the first line speed before the turn by the first conveying unit 6 and the belt line speed by the belt conveying unit 8 is variable with respect to the line speed before the turn. In order to prevent problems such as turning of the leading edge of the paper S, the belt linear speed needs to be faster than the line speed before the turn. On the other hand, since the linear velocity at the leading edge and the trailing edge of the sheet S becomes equal after the conveyance belt 82 conveys the sheet and begins to be nipped and conveyed by the nip portion of the second conveyance means 7, the belt linear velocity is the same as the linear velocity before the turn. Good. At this time, if the belt linear velocity is increased, other problems such as rubbing may occur. Therefore, by changing the relative speed between the linear velocity before the turn and the belt linear velocity as the paper advances, the leading edge of the paper S can be conveyed without causing problems such as turning over to the conveying belt 82.

Secondly, the belt linear speed> the pre-turn linear speed is established, and the belt linear speed = the linear speed before the turn and the relative speed change when at least the leading edge of the sheet S starts to be nipped by the nip portion of the second conveying unit 7. Since it has, there exists the following effect. That is, when the paper enters the conveying surface 82a of the conveying belt 82 while buckling, the leading end of the sheet abuts against the conveying surface 82a of the conveying belt 82, and then sequentially conveys from the leading end portion toward the nip portion of the second conveying means 7. It will be done. At that time, as described above, since the belt linear velocity is higher than the pre-turn linear velocity, it is possible to convey the belt S without causing the problem of turning the leading edge of the paper S by setting “belt linear velocity> pre-turn linear velocity”. After starting to be nipped and transported in the nip portion of the second transport means 7, it is possible to transport without causing problems such as rubbing at the nip portion by setting “belt linear speed = line speed before turn”.
Thirdly, as a method of changing the relative speed between the linear speed before the turn and the belt linear speed, it is possible to change the relative speed with a simple configuration by switching the belt linear speed so as to decelerate instantaneously. As a result, there are advantages and effects such as space saving and low cost.

(Second Embodiment)
The second embodiment will be described with reference to FIG. The second embodiment shown in FIG. 15 has a partial control function of the CPU 44 of the control device 43 shown in FIG. 12 and the paper conveying device 5A of the first embodiment shown in FIGS. The main difference is that the content stored in the ROM 45 is changed to obtain the linear velocity diagram shown in FIG. The second embodiment is the same as the control configuration of the sheet conveying apparatus 5A of the first embodiment except for the differences.

Compared with that of the first embodiment, the CPU 44 of the control device 43 in the second embodiment replaces the second control function with the output signal and belt related to the pre-turn linear velocity from the paper linear velocity detection sensor 39. Based on the output signal related to the belt linear velocity from the linear velocity detection sensor 40, the pre-turn linear velocity v ₁ , the belt linear velocity v ₂ , and the times t ₁ and t ₂ shown in FIG. However, from the time when the leading edge of the sheet S conveyed by the first conveying means 6 comes into contact with the conveying surface 82a of the conveying belt 82 to the time before the nip portion of the second conveying means 7 starts to be nipped and conveyed, the belt line The second conveying motor 30 is controlled so that the speed v ₂ (second linear velocity) is constant, and at least before the beginning of the nipping / conveying by the nip portion of the second conveying means 7, the pre-turn linear velocity v ₁ It has a control function of controlling the first conveyance motor 29 so as to be equal to the increase Hayashi switched belt linear speed of the first linear velocity) instantaneously.

FIG. 15 shows changes in the belt linear velocity according to this embodiment. As shown in the figure, the belt linear velocity v ₂ is before the leading edge of the sheet S passes through the first conveying unit 6 is controlled to be faster than the turn fronts speed v _1. After time t _{1 when the} sheet S is further conveyed and passes through the first conveying unit 6 and the leading end of the sheet S comes into contact with the conveying surface 82a of the conveying belt 82, the leading end of the sheet S becomes the nip portion of the second conveying unit 7. in a faster time than the time t ₂ which is sandwiched and conveyed, turn front velocity v ₁ is switched to be equal to the increase Hayashi belt linear velocity v ₂ instantly.

  As described above, according to the second embodiment, as compared with the effect according to the first embodiment, instead of the third effect, as a method of changing the relative speed between the linear velocity before turn and the belt linear velocity, By having a configuration that switches the front speed of the turn to increase instantaneously, it is possible to change the relative speed with a simple configuration, which differs only in that it provides advantages and effects such as space saving and low cost. In addition, the same effects as the first and second effects according to the first embodiment are achieved.

(Modification 1 of the first embodiment)
With reference to FIG. 16, the modification 1 of 1st Embodiment is demonstrated. The first modification of the first embodiment shown in FIG. 16 (hereinafter, also referred to as “modification 1”) is compared with the sheet conveying device 5A of the first embodiment shown in FIGS. 12 is mainly configured so that the linear velocity diagrams shown in FIGS. 16A and 16B can be obtained by changing the partial control function of the CPU 44 of the control device 43 shown in FIG. Is different. The modified example 1 is the same as the control configuration of the sheet conveying apparatus 5A of the first embodiment except for the differences.

As compared with that of the first embodiment, the CPU 44 of the control device 43 according to the first modification example replaces the second control function with the output signal and the belt linear velocity related to the linear velocity before the turn from the paper linear velocity detection sensor 39. Based on the output signal related to the belt linear velocity from the detection sensor 40, the pre-turn linear velocity v ₁ , the belt linear velocity v ₂ , the times t ₁ and t _{2 shown} in FIGS. Referring to these as appropriate, before the leading edge of the sheet S conveyed by the first conveying means 6 comes into contact with the conveying surface 82a of the conveying belt 82, before being nipped and conveyed by the nip portion of the second conveying means 7. Up to the point where the first conveying motor 29 is controlled so that the linear velocity v ₁ before the turn is constant, and at least until immediately before the leading edge of the sheet S is nipped and conveyed by the nip portion of the second conveying means 7 Line speed ₂ gradually (progressively) to decelerate to equal the turn front speed v _1, having a second control function for controlling the second conveyance motor 30 to change the belt linear velocity v ₂ continuously.
Here, “continuously changing the belt linear velocity v ₂ ” means that the belt linear velocity v ₂ takes a continuous value with the time accompanying the conveyance of the paper S as shown in FIG. meant to also include that we switched stepwise for each time interval in the belt linear velocity v _2, as shown in FIG. 16 (b).

FIGS. 16A and 16B show changes in the belt linear velocity of the present modification. As shown in the figure, the belt linear velocity v ₂ is before the leading edge of the sheet S passes through the first conveying unit 6 is controlled to be faster than the turn fronts speed v _1. After time t _{1 when the} sheet S is further conveyed, passes through the first conveying unit 6, and the leading edge of the sheet S comes into contact with the conveying surface 82 a of the conveying belt 82, the belt linear velocity v ₂ is gradually decelerated and the sheet S The belt linear velocity v ₂ is continuously changed and switched so as to be equal to the pre-turn linear velocity v ₁ at a timing faster than the time t ₂ when the leading edge of the belt is nipped and conveyed by the nip portion of the second conveying means 7.

  As described above, according to the first modification, instead of the third effect according to the first embodiment, the belt linear speed is gradually reduced as a method of changing the relative speed between the pre-turn linear speed and the belt linear speed. Thus, when considering the behavior of the sheet S when entering the conveyor belt 82 in the turn portion, the linear velocity at the leading end of the sheet S follows the guide surface 71a of the conveyance guide member 71. Therefore, the leading edge of the paper S is prevented from being turned over by changing the belt linear velocity continuously and changing the belt linear speed accordingly. In addition, there is an effect that the paper S can be conveyed without causing a problem of rubbing of the leading edge of the paper S.

(Modification 2 of the second embodiment)
With reference to FIG. 17, the modification 2 of 2nd Embodiment is demonstrated. The second modification of the second embodiment shown in FIG. 17 (hereinafter also referred to as “Modification 2”) is different from the second embodiment shown in FIG. 15 in that the control device 43 shown in FIG. The main difference is that a part of the control function of the CPU 44 and the contents stored in the ROM 45 are changed so that the linear velocity diagrams shown in FIGS. 17A and 17B can be obtained. The modified example 2 is the same as the control configuration of the sheet conveying device 5A of the second embodiment except for the differences.

Compared with that of the second embodiment, the CPU 44 of the control device 43 according to the second modified example replaces the second control function with the output signal and the belt linear velocity relating to the linear velocity before the turn from the paper linear velocity detection sensor 39. Based on the output signal relating to the belt linear velocity from the detection sensor 40, the pre-turn linear velocity v ₁ , the belt linear velocity v ₂ , the times t ₁ and t _{2 shown} in FIGS. With reference to these as appropriate, from the time when the leading edge of the sheet S conveyed by the first conveying means 6 contacts the conveying surface 82a of the conveying belt 82 to before it is nipped and conveyed by the nip portion of the second conveying means 7. controls the second conveying motor 30 so that the belt linear velocity v ₂ becomes constant, and the just before the leading edge of the sheet S begins to be nipped and conveyed by at least the nip portion of the second conveying unit 7 turns fronts the speed v There gradually as (gradually) and accelerated equal to the belt linear speed, a second control function of controlling the first conveyance motor 29 so as to turn front speed v ₁ continuously change.
Here, “continuously changing the pre-turn linear velocity” means that the pre-turn linear velocity v ₁ takes a continuous value with the time accompanying the conveyance of the paper S as shown in FIG. As shown in FIG. 17 (b), this means that the pre-turn linear velocity v ₁ is switched step by step at certain time intervals.

FIGS. 17 (a) and 17 (b) show changes in the line speed before the turn in this modification. As shown in the figure, the belt linear velocity v ₂ is before the leading edge of the sheet S passes through the first conveying unit 6 is controlled to be faster than the turn fronts speed v _1. After time t _{1 when the} sheet S is further conveyed and passes through the first conveying means 6 and the leading edge of the sheet S comes into contact with the conveying surface 82a of the conveying belt 82, the pre-turn linear velocity v ₁ is gradually increased, at a faster timing than the time t ₂ when the leading end of the S is the leading end of the sheet S is nipped and conveyed to the nip portion of the second conveying unit 7, the turn fronts speed v1 is to be equal to the belt linear velocity v _2, continuously Change and switch.

  As described above, according to the second modification, instead of the third effect according to the second embodiment, the relative linear velocity before turn (first linear velocity) and the belt linear velocity (second linear velocity) are relative to each other. As a method of changing the speed, by having a configuration in which the linear velocity before the turn is continuously changed so as to gradually increase, when considering the behavior of the paper S when entering the conveyor belt 82 in the turn portion, Since the linear velocity at the tip moves along the guide surface 71a of the conveyance guide member 71 and changes the entrance angle of the conveyance belt 82 with respect to the conveyance surface 82a, it changes with conveyance. By switching to this, it is possible to prevent the leading edge of the sheet S from being turned over and to carry the sheet without causing the problem of rubbing the leading edge of the sheet S.

(Third embodiment)
A third embodiment will be described with reference to FIGS. 18 and 19. In the third embodiment shown in both figures, compared with the sheet conveying device 5A of the first embodiment shown in FIGS. 11 to 14, a partial control function of the CPU 44 of the control device 43 shown in FIG. The main difference is that the content stored in the ROM 45 is changed to obtain the linear velocity diagram shown in FIG. The third embodiment is the same as the control configuration of the sheet conveying apparatus 5A of the first embodiment except for the differences.

Before entering the description of the change in the belt linear velocity shown in FIG. 19, referring to FIG. 18, the approach angle θ is determined from the general conditional expression (A1) for preventing the leading edge of the paper S from turning up. A conditional expression (A2) in consideration is obtained.
Here, the entrance angle θ ₀ is plain paper in addition to relatively high-stiffness paper such as thick paper, such as the paper transport device 5 shown in FIGS. 8 to 10 and the paper transport device 5A shown in FIG. 18 and 21 (a), the center of the nip portion of the first conveying means 6, the first conveying means 6 and the second conveying means 7, A straight line passing through the downstream end (upper end in the figure) of the conveyance guide member 71 that is in the outer direction of the sheet conveyance path (first conveyance path A) and closest to the belt conveyance means 8. leading edge of the sheet S is conveyed (when _{t = 0 = t 1, θ} = θ 0) when starting to contact the conveying surface 82a of the belt 82 to the through conveyor belt 82 to nip the center of the first conveying unit 6 Means an angle formed by a perpendicular line k 'and a perpendicular line k' parallel to the conveying surface 82a. Hereinafter, θ _{0 is referred} to as an entry angle of the leading end portion of the sheet S with respect to the conveyance surface 82 a of the conveyance belt 82.
The approach angle θ is an angle when the leading edge of the paper S changes with time t after the leading edge of the paper S comes into contact with the transport surface 82 a of the transport belt 82.
In FIG. 18, general conditions for preventing the leading edge of the paper S from being turned over are given by v ₁ ≦ v ₂ (A1). The leading edge of the sheet S conveyed by the first conveying means 6 when l (el) is the distance from the center of the nip portion of the first conveying means 6 to the contact point where the perpendicular line k contacts the conveying surface 82a of the conveying belt 82. Is determined.
v ₁ dt + l × 1 / cos θ = 1 × 1 / cos (θ + dθ) (1)
dx + ltanθ = ltan (θ + dθ) (2)
From (1) and (2),
(Dx + ltan θ) ² = v ₁ ² dt ² + 2v ₁ ldt / cos θ + l ² tan ² θ
dx ² + 2dxltan θ + l ² tan ² θ = v ₁ ² dt ² + 2v ₁ ldt / cos θ + l ² tan ² θ
2dxltanθ = 2v ₁ ldt / cosθ
∴v = dx / dt = v ₁ / sin θ
From this, the conditional expression (A2) is obtained as follows.
v ₁ / sin θ ≦ v ₂ (A2) is obtained. When from t = 0 of (t1) which, because it is theta = theta _0, the _{v 2 ≧ v 1 / sinθ 0} .

The CPU 44 of the control device 43 in the third embodiment replaces the first control function as compared with that in the first embodiment based on the conditional expression (A2) obtained with reference to FIG. Based on the output signal relating to the linear velocity before turn from the paper linear velocity detection sensor 39 and the output signal relating to the belt linear velocity from the belt linear velocity detection sensor 40, the linear velocity before turn v ₁ , the belt linear velocity v ₂ shown in FIG. After calculating and calculating the times t ₁ and t ₂ as appropriate and referring to them appropriately, after the leading edge of the sheet S conveyed by the first conveying means 6 comes into contact with the conveying surface 82a of the conveying belt 82 before contacting. a is up before starting is sandwiched and conveyed by the nip portion of the second conveying unit _{7, v 2 ≧ v 1 /} sinθ 0 or _{v 2} ≒ _v so that 1 / sin [theta linear velocity which satisfies the relationship of ₀ The tip of the paper S is Is hereinafter when started to be sandwiched and conveyed by the nip portion of the second conveying unit 7, v 2 ₌ v so that the linear velocity which satisfies the relational expression _1, controls the first conveying motor 29 and the second conveying motor 30 Only the first control function is different.

Further, the CPU 44 has the same control function as the second control function of the first embodiment, that is, from the time when the leading edge of the paper S conveyed by the first conveying means 6 contacts the conveying surface 82a of the conveying belt 82. until before starting is sandwiched and conveyed by the nip portion of the second conveying unit 7, turn front speed v ₁ controls the first conveying motor 29 to be constant, and, at least the nip portion of the second conveying unit 7 a second control function for controlling the second conveyance motor 30 so that the belt linear velocity v ₂ becomes equal to the turn-front speed v ₁ is switched decelerates instantaneously the time immediately before the leading edge of the sheet S begins to be nipped and conveyed Have

As shown in FIG. 19, before the leading edge of the sheet S passes through the first conveying means 6 and after the leading edge of the sheet S contacts the conveying surface 82 a of the conveying belt 82, the nip portion of the second conveying means 7 until that begins to be sandwiched and conveyed, _{v 2} ≧ _v 1 / sin [theta ₀ or _{v 2} ≒ _v 1 / as a linear velocity that satisfies the relationship of sin [theta _0, belt linear velocity _{v 2} is turn front velocity v It is controlled to be faster than ₁ . After the time t ₁ when the leading edge of the sheet S comes into contact with the conveying surface 82 a of the conveying belt 82, the belt linear velocity v ₂ is instantaneously reduced, and the leading edge of the sheet S is nipped and conveyed by the nip portion of the second conveying means 7. The belt linear velocity v ₂ is switched so as to be equal to the pre-turn linear velocity v ₁ at a timing faster than the time t ₂ .

As described above, according to the third embodiment, first, after the leading edge of the sheet S conveyed by the first conveying unit 6 comes into contact with the conveying surface 82a of the conveying belt 82 before contacting. Until it is nipped and transported by the nip portion of the second transport means 7, the linear velocity satisfies the relational expression of v ₂ ≧ v ₁ / sin θ ₀ or v ₂ ≈v ₁ / sin θ ₀ , Since the leading edge of the sheet S starts to be nipped and conveyed by the nip portion of the second conveying means 7, the relative speed changes so that the linear velocity satisfies the relational expression of v ₂ = v ₁ . When the leading edge of the paper S enters the conveying surface 82a of the conveying belt 82 while buckling, the leading edge of the sheet S hits the conveying surface 82a of the conveying belt 82, and thereafter, sequentially from the leading edge toward the nip portion of the second conveying means 7. It will be transported. At this time, as described above, the belt linear velocity v ₂ is faster than the pre-turn linear velocity v ₁ , and therefore, at least when the leading edge of the sheet S contacts the conveyance surface 82 a of the conveyance belt 82, “v ₂ ≧ v ₁ / sin θ ₀ Or, by satisfying the relational expression of v ₂ ≈v ₁ / sin θ _0, it is possible to enter the conveyance surface 82a of the conveyance belt 82 without causing the problem of turning up the leading edge of the sheet S (see Conditional Expression (A2)). ). After the leading edge of the sheet S starts to be nipped and conveyed by the nip portion of the second conveying means 7, the belt linear velocity v ₂ = the pre-turn linear velocity v ₁ causes problems such as rubbing at the nip portion. Can be transported without any problem.
Secondly, as a method of changing the relative speed between the linear speed before the turn and the belt linear speed, it is possible to change the relative speed with a simple configuration by switching the belt linear speed so as to decelerate instantaneously. Thus, there are advantages and effects such as space saving and cost reduction.

(Fourth embodiment)
A fourth embodiment will be described with reference to FIGS. 18 and 20. In the fourth embodiment shown in both figures, compared with the sheet conveying device 5A of the third embodiment shown in FIGS. 18 and 19, a partial control function of the CPU 44 of the control device 43 shown in FIG. The main difference is that the content stored in the ROM 45 is changed to obtain the linear velocity diagram shown in FIG. The fourth embodiment is the same as the control configuration of the sheet conveying device 5A of the third embodiment except for the differences.

Compared with that of the third embodiment, the CPU 44 of the control device 43 in the fourth embodiment replaces the first control function with the output signal and belt related to the line speed before turn from the paper linear speed detection sensor 39. Based on the output signal related to the belt linear velocity from the linear velocity detection sensor 40, the pre-turn linear velocity v ₁ , the belt linear velocity v ₂ , and the times t ₁ and t ₂ shown in FIG. On the other hand, after the leading edge of the sheet S conveyed by the first conveying means 6 comes into contact with the conveying surface 82a of the conveying belt 82 before it comes into contact with the nip portion of the second conveying means 7, it begins to be nipped and conveyed. Until then, the leading edge of the sheet S is clamped by the nip portion of the second conveying means 7 so that the linear velocity satisfies the relational expression of v ₂ ≧ v ₁ / sin θ ₀ or v ₂ ≈v ₁ / sin θ _0. Being transported The subsequent time, v 2 ₌ v so that the linear velocity which satisfies the relational expression _1, it is different with a first control function of controlling the first conveyance motor 29 and the second conveyance motor 30.

The CPU 44 also has a control function similar to the second control function of the second embodiment, that is, from the time when the leading edge of the sheet S conveyed by the first conveying means 6 contacts the conveying surface 82a of the conveying belt 82. until before starting it is sandwiched and conveyed by the nip portion of the second conveying unit 7, and controls the second conveying motor 30 so that the belt linear velocity v ₂ becomes constant, and, at least the nip portion of the second conveying unit 7 The first transport motor 29 is controlled so that the pre-turn linear velocity v ₁ is instantaneously increased and switched to be equal to the belt linear velocity v ₂ immediately before the time t ₂ when the leading edge of the sheet S starts to be nipped and conveyed. Has a second control function.

As shown in FIG. 20, before the leading edge of the sheet S passes through the first conveying means 6 and after the leading edge of the sheet S contacts the conveying surface 82a of the conveying belt 82, the nip portion of the second conveying means 7 until that begins to be sandwiched and conveyed, _{v 2} ≧ _v 1 / sin [theta ₀ or _{v 2} ≒ _v 1 / as a linear velocity that satisfies the relationship of sin [theta _0, belt linear velocity _{v 2} is turn front velocity v It is controlled to be faster than ₁ . After a time t ₁ when the leading edge of the sheet S comes into contact with the conveying surface 82 a of the conveying belt 82, the pre-turn linear velocity v ₁ is instantaneously increased, and the leading edge of the sheet S is nipped and conveyed by the nip portion of the second conveying means 7. The turn-before linear speed v ₁ is switched to be equal to the belt linear speed v ₂ at a timing faster than the time t ₂ .

As described above, according to the fourth embodiment, the same effect as the first effect according to the third embodiment can be obtained.
Second, as a method of changing the relative speed between the line speed before the turn and the belt speed, it is possible to change the relative speed with a simple structure by switching the speed before the turn so as to increase instantaneously. As a result, there are advantages and effects such as space saving and low cost.

(Modification 3 of the third embodiment)
A modification 3 of the third embodiment will be described with reference to FIGS. 21 and 22 (hereinafter, also referred to as “modification 3”). The modification 3 shown in both figures is a partial control function of the CPU 44 of the control device 43 shown in FIG. 12, as compared with the control configuration of the sheet conveying device 5A in the third embodiment shown in FIGS. The main difference is that the storage contents of the ROM 45 are changed so as to obtain the linear velocity diagrams shown in FIGS. Modification 3 is the same as the control configuration of the sheet conveying apparatus 5A in the third embodiment described with reference to FIGS. 18 and 19 except for the differences.

Before entering the description of the change in belt linear velocity shown in FIGS. 22A and 22B, referring to FIGS. 18 and 21A, 21B, and 21C, the time t Conditional expressions (B1 to B3) for preventing the leading edge of the sheet S from being turned up when the approach angle θ that changes with the angle is taken into consideration are obtained.
In FIG. 18 and FIG. 21A, v ₂ > v ₁ / sin θ ₀ (B1) is given until the leading edge of the paper S comes into contact with the conveyance surface 82a of the conveyance belt 82.
In FIG. 18 and FIG. 21 (b), after the leading edge of the sheet S comes into contact with the conveyance surface 82 a of the conveyance belt 82 and before it is sandwiched and conveyed by the nip portion of the second conveyance means 7,
v ₂ > v ₁ / sin θ ₀ (B2)
At this time, it is determined that θ = cos ⁻¹ {1 / (v ₁ × t / l + 1 / cos θ ₀ )}. In FIG. 18, l / cos (θ + dθ) = l / cos θ + vdt
From this, dθ / dt = v × cos ² θ / l × sin θ
When 1 / cos θ = v × t / l + C t = 0, θ = θ ₀
∴θ = cos ⁻¹ {1 / (v ₁ × t / l + 1 / cos θ ₀ )}
In FIG. 21C, after the leading edge of the sheet S is nipped by the nip portion of the second conveying means 7, v ₂ = v ₁ (B3)

The CPU 44 of the control device 43 according to the third modified example turns the turn from the sheet linear velocity detection sensor 39 in place of the first control function as compared with that of the third embodiment described with reference to FIGS. 18 and 19. Based on the output signal relating to the front linear velocity and the output signal relating to the belt linear velocity from the belt linear velocity detection sensor 40, the turn linear velocity v ₁ , the belt linear velocity v ₂ shown in FIG. 22 (a) or 22 (b), Times t ₁ and t ₂ are appropriately calculated and obtained, and reference is made to these until the leading edge of the paper S comes into contact with the conveyance surface 82a of the conveyance belt 82.
The linear velocity satisfies the relational expression of v ₂ ≧ v ₁ / sin θ ₀ or v ₂ ≈v ₁ / sin θ ₀ (where θ _{0 is the} angle of entry of the leading end of the sheet S with respect to the conveying surface 82a of the conveying belt 82). As described above, until the leading edge of the sheet S comes into contact with the conveyance surface 82a of the conveyance belt 82 and before it is nipped and conveyed by the nip portion of the second conveyance means 7,
v ₂ ≧ v ₁ / sin θ or v ₂ ≈v ₁ / sin θ,
However, the leading edge of the sheet S is nipped by the nip portion of the second conveying unit 7 so that the linear velocity satisfying the relational expression θ = cos ⁻¹ {1 / (v ₁ × t / 1/1 / cos θ ₀ )}. After the start of conveyance, it has a first control function for controlling the first conveyance motor 29 and the second conveyance motor 30 so that the linear velocity satisfies the relational expression of v ₂ = v _1. Mainly different.

In addition, CPU 44, after the leading edge of the sheet S contacts the conveying surface 82a of the conveyor belt 82, until before starting is sandwiched and conveyed by the nip portion of the second conveying unit 7, comprising turns front velocity v ₁ is a constant controls the first conveying motor 29 as, and the tip of the sheet S is belt linear velocity v ₂ gradually (progressively) decelerated until just before the start is sandwiched and conveyed by at least the nip portion of the second conveying unit 7 to be equal to the turn-front speed v ₁ Te, a second control function for controlling the second conveyance motor 30 to change the belt linear velocity v ₂ continuously.
Here, “continuously changing the belt linear velocity v ₂ ” means that the belt linear velocity v ₂ takes a continuous value with the time accompanying the conveyance of the sheet S as shown in FIG. meant to also include that we switched stepwise for each time interval in the belt linear velocity v _2, as shown in FIG. 22 (b).

22 (a) and 22 (b) show changes in the belt linear velocity of this modification. As shown in the figure, before the leading edge of the sheet S passes through the first conveying means 6, the linear velocity satisfying the relational expression of v ₂ ≧ v ₁ / sin θ ₀ or v ₂ ≈v ₁ / sin θ ₀ so that, the belt linear velocity v ₂ is controlled to be faster than the turn fronts speed v _1. After the sheet S is further conveyed and passes through the first conveying unit 6 and the leading edge of the sheet S comes into contact with the conveying surface 82a of the conveying belt 82, until the sheet S starts to be nipped and conveyed by the nip portion of the second conveying unit 7. ,
v ₂ ≧ v ₁ / sin θ or v ₂ ≈v ₁ / sin θ,
However, the belt linear velocity v ₂ is gradually reduced so that the linear velocity satisfying the relational expression of θ = cos ⁻¹ {1 / (v ₁ × t / l + 1 / cos θ ₀ )} is satisfied, and the leading edge of the paper S Is continuously changed and switched so that the belt linear velocity v ₂ becomes equal to the pre-turn linear velocity v ₁ at a timing faster than the time t ₂ that is sandwiched and conveyed by the nip portion of the second conveying means 7.
Note that the deceleration curves shown by the broken lines in FIGS. 22A and 22B are v = v ₁ / sin θ,
The case of θ = cos ⁻¹ {1 / (v ₁ × t / l + 1 / cos θ ₀ )} is shown.

As described above, according to the modified example 4, as described above with reference to FIGS. 18, 21, 23 (a) and (b), the leading edge of the sheet S passes through the first transport unit 6, Since the belt linear velocity is higher than the pre-turn linear velocity before contacting the conveyance surface 82a of the conveyance belt 82, at least when the leading edge of the sheet S contacts the conveyance surface 82a of the conveyance belt 82, “v ₂ ≧ v _By setting ₁ / sin θ or v ₂ ≈v ₁ / sin θ, it is possible to enter the conveyance surface 82a of the conveyance belt 82 without causing the problem of turning up the leading edge of the sheet S. Thereafter, in a state where the leading edge of the sheet S is being conveyed by the conveying belt 82, the entry angle θ of the leading end of the sheet S and the conveying belt 81 change with time t, and therefore “v ₂ ≧ v ₁ / sin θ or v ₂ ≒ _v 1 / _sinθ, ^{where, θ = cos -1 {1 /} (v 1 × t / l + 1 / cosθ 0)} "by satisfying the relational expression, curling even during conveyance of the sheet S by the conveyor belt 82 The leading edge of the paper S can be conveyed without any problem.
Then, after the leading edge of the sheet S begins to be nipped and conveyed by the nip portion of the second conveying means 7, the nip of the leading edge of the sheet S is set to “Belt linear velocity v ₂ = Linear velocity before turn v ₁ ”. There is an effect that it can be transported without causing problems such as rubbing at the part.

(Modification 4 of the fourth embodiment)
A modification 4 of the fourth embodiment will be described with reference to FIGS. 21 and 23 (hereinafter also referred to as “modification 4”). The modification 4 shown in both figures is a partial control function of the CPU 44 of the control device 43 shown in FIG. The main difference is that the storage contents of the ROM 45 are changed so that the linear velocity diagrams shown in FIGS. 23A and 23B can be obtained. Modification 4 is the same as the control configuration of the sheet conveying apparatus 5A in the fourth embodiment described with reference to FIGS. 18 and 20 except for the differences.

The CPU 44 of the control device 43 in the modified example 4 uses the turn from the sheet linear velocity detection sensor 39 in place of the first control function as compared with that of the fourth embodiment described with reference to FIGS. Based on the output signal relating to the front linear velocity and the output signal relating to the belt linear velocity from the belt linear velocity detection sensor 40, the turn linear velocity v ₁ , belt linear velocity v ₂ shown in FIG. 23 (a) or FIG. 23 (b), Times t ₁ and t ₂ are appropriately calculated and obtained, and reference is made to these until the leading edge of the paper S comes into contact with the conveyance surface 82a of the conveyance belt 82.
The linear velocity satisfies the relational expression of v ₂ ≧ v ₁ / sin θ ₀ or v ₂ ≈v ₁ / sin θ ₀ (where θ _{0 is the} angle of entry of the leading end of the sheet S with respect to the conveying surface 82a of the conveying belt 82). As described above, until the leading edge of the sheet S comes into contact with the conveyance surface 82a of the conveyance belt 82 and before it is nipped and conveyed by the nip portion of the second conveyance means 7,
v ₂ ≧ v ₁ / sin θ or v ₂ ≈v ₁ / sin θ,
However, the leading edge of the sheet S is nipped by the nip portion of the second conveying unit 7 so that the linear velocity satisfying the relational expression θ = cos ⁻¹ {1 / (v ₁ × t / 1/1 / cos θ ₀ )}. After the start of conveyance, it has a first control function for controlling the first conveyance motor 29 and the second conveyance motor 30 so that the linear velocity satisfies the relational expression of v ₂ = v _1. Mainly different.

In addition, CPU 44, after the leading edge of the sheet S contacts the conveying surface 82a of the conveyor belt 82, until the second begins to be nipped and conveyed by the nip portion of the conveying means 7 becomes constant belt linear velocity v ₂ controls the second conveying motor 30 as and turn front velocity v ₁ is the time immediately before the leading edge of the sheet S begins to be nipped and conveyed by at least the nip portion of the second conveying unit 7 is gradually (progressively) speed increasing Thus, a second control function for controlling the first transport motor 29 so as to continuously change the pre-turn linear velocity v ₁ so as to be equal to the belt linear velocity v ₂ is provided.
Here, “continuously changing the pre-turn linear velocity v ₁ ” means that the pre-turn linear velocity v ₁ takes a continuous value with the time accompanying the conveyance of the sheet S as shown in FIG. meant to also include that we switched stepwise for each time interval in turn front speed v ₁ as shown in FIG. 23 (b).

23 (a) and 23 (b) show changes in the belt linear velocity according to this modification. As shown in the figure, before the leading edge of the sheet S passes through the first conveying means 6, the linear velocity satisfying the relational expression of v ₂ ≧ v ₁ / sin θ ₀ or v ₂ ≈v ₁ / sin θ ₀ so that, the belt linear velocity v ₂ is controlled to be faster than the turn fronts speed v _1. After the sheet S is further conveyed and passes through the first conveying unit 6 and the leading edge of the sheet S comes into contact with the conveying surface 82a of the conveying belt 82, until the sheet S starts to be nipped and conveyed by the nip portion of the second conveying unit 7. ,
v ₂ ≧ v ₁ / sin θ or v ₂ ≈v ₁ / sin θ,
However, the linear velocity v ₁ before the turn is gradually increased so that the linear velocity satisfying the relational expression θ = cos ⁻¹ {1 / (v ₁ × t / 1/1 / cos θ ₀ )} is satisfied. tip at a faster timing than the sandwiched and conveyed by the time t ₂ to the nip of the second conveying unit 7, turn front velocity v ₁ is to be equal to the belt linear velocity v _2, switched continuously changes.
Incidentally, FIG. 23 (a), the deceleration curve shown by a broken line in (b) _{is, v} = _v 1 / _sinθ,
The case of θ = cos ⁻¹ {1 / (v ₁ × t / l + 1 / cos θ ₀ )} is shown.

As described above, according to the modified example 4, as described above with reference to FIGS. 18, 21, 23 (a) and (b), the leading edge of the sheet S passes through the first transport unit 6, Since the belt linear velocity is higher than the pre-turn linear velocity before contacting the conveyance surface 82a of the conveyance belt 82, at least when the leading edge of the sheet S contacts the conveyance surface 82a of the conveyance belt 82, “v ₂ ≧ v _By setting ₁ / sin θ or v ₂ ≈v ₁ / sin θ, it is possible to enter the conveyance surface 82a of the conveyance belt 82 without causing the problem of turning up the leading edge of the sheet S. Thereafter, in a state where the leading edge of the sheet S is being conveyed by the conveying belt 82, the entry angle θ of the leading end of the sheet S and the conveying belt 81 change with time t, and therefore “v ₂ ≧ v ₁ / sin θ or v ₂ ≒ _v 1 / _sinθ, ^{where, θ = cos -1 {1 /} (v 1 × t / l + 1 / cosθ 0)} "by satisfying the relational expression, curling even during conveyance of the sheet S by the conveyor belt 82 The leading edge of the paper S can be conveyed without any problem.
Then, after the leading edge of the sheet S begins to be nipped and conveyed by the nip portion of the second conveying means 7, the nip of the leading edge of the sheet S is set to “Belt linear velocity v ₂ = Linear velocity before turn v ₁ ”. There is an effect that it can be transported without causing problems such as rubbing at the part.

(Fifth embodiment)
The fifth embodiment will be described with reference to FIG. In the fifth embodiment shown in the figure, for example, compared with the control configuration of the sheet conveying apparatus 5A in the third embodiment shown in FIGS. 18 and 19, the CPU 44 of the control device 43 shown in FIG. This is mainly different in that the linear velocity diagram shown in FIG. 24 can be obtained by changing the part control function and the contents stored in the ROM 45. The fifth embodiment is the same as the control configuration of the sheet conveying device 5A in the third embodiment described with reference to FIGS. 18 and 19 except for the differences.

Compared with that of the third embodiment, the CPU 44 of the control device 43 in the fifth embodiment outputs an output signal relating to the line speed before turn from the paper linear speed detection sensor 39 and the belt line from the belt linear speed detection sensor 40. Based on the output signal related to the speed, the first conveying means 6 refers to the front turn linear velocity v ₁ , belt linear velocity v ₂ , time t ₁ , t ₂ shown in FIG. conveying surface belt linear velocity before contacting the 82a v ₂ is faster linear velocity than the turn fronts speed v ₁ of the leading edge of the sheet that has been conveyed the conveyor belt 82 (belt linear velocity v _2> turn fronts speed v ₁₎ As shown in the figure, the pre-turn linear velocity v ₁ is the belt linear velocity after the leading edge of the sheet comes into contact with the conveying surface 82a of the conveying belt 82 and before it is nipped and conveyed by the nip portion of the second conveying means 7. than v ₂ And so that temporarily higher linear velocity (v _{1> v 2),} the leading end of the sheet is subsequently when started to be nipped and conveyed by the nip portion of the second conveying unit 7, a belt linear velocity v ₂ is turned front speed v to be ₁ equal linear velocity, it differs only by having a first control function of controlling the first conveyance motor 29 and the second conveyance motor 30.

In addition, the CPU 44 starts from when the leading edge of the sheet S conveyed by the first conveying means 6 comes into contact with the conveying surface 82a of the conveying belt 82 and before being nipped and conveyed by the nip portion of the second conveying means 7. The first conveying motor 29 is controlled so that the pre-turn linear velocity v ₁ is constant, and at least immediately after the leading edge of the sheet S comes into contact with the conveying surface 82a of the conveying belt 82, the belt linear velocity v ₂ is instantaneously increased. a second control function for controlling the second conveyance motor 30 as deceleration switched to be equal to the turn-front speed v _1.

As shown in FIG. 24, v ₂ ≧ v ₁ / sin θ ₀ or before the leading edge of the sheet S passes through the first conveying means 6 and before the leading edge of the sheet S contacts the conveying surface 82a of the conveying belt 82. The linear velocity is controlled so as to satisfy the relational expression of v ₂ ≈v ₁ / sin θ ₀ . After the time t ₁ when the leading edge of the paper S comes into contact with the conveyance surface 82a of the conveyance belt 82, the belt linear velocity v ₂ is instantaneously decelerated, and then the pre-turn linear velocity v ₁ is temporarily higher than the belt linear velocity v _2. Switching is made so that the linear velocity is high (v ₁ > v ₂ ), and skew correction of the leading edge of the paper S is performed. Thereafter, the belt linear velocity v ₂ is switched to be equal to the pre-turn linear velocity v ₁ at a timing faster than the time t ₂ when the leading edge of the sheet S is nipped and conveyed by the nip portion of the second conveying means 7.

As described above, according to the fifth embodiment, after the time t ₁ when the leading edge of the sheet S comes into contact with the conveyance surface 82 a of the conveyance belt 82, the pre-turn linear velocity v ₁ is temporarily higher than the belt linear velocity v _2. Therefore, the sheet S is pushed forward from the rear end side by the conveyance of the first conveyance unit 6 by being controlled so as to have an extremely fast linear velocity (v ₁ > v ₂ ). As a result, the leading edge of the sheet S is pushed up toward the conveying surface 82a of the conveying belt 82 due to the stiffness of the relatively rigid sheet S such as thick paper, and the antinode (effective conveying surface) of the conveying belt 82 is pushed up. The leading edge position of the sheet S is aligned toward the. Thereby, the skew of the leading edge of the paper S is corrected, and the effect of (pre) resist can be realized. Needless to say, in the fifth embodiment, in addition to the effects described above, for example, the same effects as in the third embodiment are also achieved.
In other words, in the fifth embodiment, for example, the CPU 44 of the control device 43 shown in FIG. It can also be considered that the configuration is made so that the linear velocity diagram shown in FIG.

Needless to say, the present invention is not limited to the sheet conveying apparatus 5A, but is also applicable to the sheet conveying apparatus 5 having the belt conveying means 8 shown in FIGS. 1 to 6 and FIGS.
In the above example, the embodiment, and the like, the following advantages are obtained by setting the grip roller 81 side to the drive side as in the drive mechanism 22 shown in FIGS. 4 and 5 and the drive mechanism shown in FIG. It is done. That is, the conveying belt 82 of the belt conveying means 8 is brought into direct contact with the gripping roller 81 (rotary conveying driving means / rotary conveying driving member) rotated by the driving mechanism 22 or the driving mechanism shown in FIG. Therefore, the variation in the linear velocity of the conveyor belt 82 can be reduced by driving the grip roller 81 side than when driving the conveyor belt 82 side. As a result, the conveyor belt 82 that rotates toward the clamping portion of the second conveyor means 7 is disposed outside (in the outer direction) of the turn of the first conveyor path A (paper transport path), so that the first conveyor path A It is possible to improve the transportability of relatively stiff paper such as thick paper at the turn portion, and by driving the grip roller 81 that faces and directly contacts the transport belt 82 and rotates the transport belt 82, a stable line can be obtained. It becomes possible to convey the sheet to the second conveying means 7 and the subsequent ones at a speed.

This advantage and effect can be easily understood by considering the following technical contents. That is, when the grip roller 81 is driven, the linear velocity of the grip roller 81 is determined only by the outer diameter and the rotational speed of the grip roller 81 itself. On the other hand, considering the case of driving the conveyor belt 82 side, when the conveyor belt 82 is driven, the conveyor belt 82 is driven by a roller-like pulley 83 (belt drive roller, main pulley) provided inside the conveyor belt 82. Is generally driven.
In this case, the linear velocity of the conveyor belt 82 is not limited to the outer diameter and the rotational speed of the pulley 83 provided inside the conveyor belt 82, but varies in the thickness of the conveyor belt 82 due to component variations and the thickness due to wear of the conveyor belt 82. Or the slip between the conveyor belt 82 and the pulley 83. For this reason, it is possible to reduce variations in the linear velocity of the conveyor belt 82 by driving the grip roller 81 side rather than driving the conveyor belt 82 side.
If the effect as described above is not so much desired, for example, the drive system for driving the grip roller 81 is removed from the drive mechanism 22 or the drive mechanism shown in FIG. And you may make it drive the conveyance belt 82 side with the drive mechanism which is not shown in figure.

  As described above, the belt conveying means 8 of each of the paper conveying devices 5 and 5A is such that one of the opposed pairs of the second conveying means 7 (the nipping and conveying means) is the leading edge or leading edge (tip, leading edge surface) of the paper (sheet). The nip portion with the grip roller 81 while gradually increasing the contact area depending on the degree of rigidity of the paper while maintaining the contact / contact state with the front end corner portion / edge). It can be said that this is an example of movement guide means for moving and guiding the paper S toward the clamping unit. Therefore, the movement guide means is not limited to the belt conveyance means 8 and may be anything as long as it has the above-described configuration and function and exhibits the above-described effects.

In the above embodiments, examples, and modifications, as shown in FIG. 1, the present invention is conveyed from the sheet storage means (paper feed tray 51) in the image forming apparatus that is a copying machine to the image forming means main body. However, the present invention is not limited to this, and the image forming apparatus is not limited to this example, and the front end of the image forming apparatus is directed upward from the upper part of the fixing device 11 in the apparatus main body. A paper conveying device (for example, see FIG. 25B) configured to discharge the paper S to be discharged from the apparatus main body to the paper discharge tray 9 in a substantially horizontal direction, or provided outside the apparatus main body. The sheet placed by the user on the substantially horizontal manual feed tray 67 is pulled into the apparatus main body while maintaining the horizontal posture, and the posture is changed upward to reach the image forming unit in the apparatus main body in the vertical direction. Transporting paper that is transported to the transport path It may be applied to a device.
That is, in the above-described embodiment and modification, the example in which the different paper (sheet) conveyance direction is changed from the substantially horizontal direction to the upward direction in the vertical direction (substantially vertical upward direction) has been described. Without being limited, it is changed from a substantially horizontal direction to a downward downward direction (substantially vertical downward), or from a vertical downward direction or an upward direction to a substantially horizontal direction (for example, FIG. 25A). Or both may be in an oblique direction or the like.

  In each of the above-described embodiments, examples, and modifications, the first transport unit and the second transport unit are both nipping and transporting units. However, depending on the transport direction of each transport unit alone, the lower surface of the transport target is set. If it is only necessary to support and convey, it is not necessary to use a nipping / conveying means in which a nipping portion by an opposing member is formed.

The members constituting the first conveying unit, the second conveying unit, and the pickup roller are not limited to those described above, and are substantially long cylindrical roller members that have a predetermined length in the axial direction of each rotating shaft. The roller member may be a short cylindrical roller member as appropriate, or a plurality of roller members or roller members may be intermittently disposed at a predetermined interval on one rotating shaft. May be.
In addition, a guide surface formed by several guide members in the outer and inner contour directions in each of the above-described embodiments is positioned at the above-described several intervals where no roller member or roller member is disposed. Good. If these guide surfaces are arranged in an appropriate regular symmetry with respect to the conveyance center line in the conveyance direction, a belt-shaped guide surface may be formed in the sheet (sheet) conveyance direction, or a substantially linear guide A surface may be formed, or these may be mixed as appropriate.

  In each of the above-described embodiments, examples, and modifications, the FRR paper feed method is adopted as the paper feed separation mechanism. However, the present invention is not limited to this, and the paper that has been fed in a predetermined multi-feed due to friction is separated. For example, an appropriate frictional separation method may be employed as long as the separation mechanism allows only one sheet to continue to advance in the conveyance direction. For example, instead of the reverse roller, a separation claw may be used instead of the above-described feed roller. Alternatively, a friction pad system having a configuration in which a friction pad that is a fixing member is in pressure contact may be employed. That is, in this friction pad system, the friction pad as a friction member is pressed against the feed roller with an appropriate separation angle and separation pressure, and the paper is placed in the nip between the feed roller and the friction pad formed thereby. I try to let it pass. Therefore, according to the paper feed separation mechanism employing the friction pad method, even if two sheets are pulled out in the overlapping state, the lower sheet receives the resistance from the friction pad between the overlapping sheets. Since it is greater than the resistance due to friction, further movement in the paper transport direction is prevented. On the other hand, the upper sheet is set so that the conveyance force received from the feed roller is larger than the resistance caused by the friction between the overlapping sheets and larger than the resistance received from the friction pad. Only continues in the transport direction.

The present invention relates to an image forming apparatus relating to a printer including not only the monochrome copying machine 1 but also a color copying machine, a monochrome laser printer, an inkjet printer, a printer using an ink transfer ribbon, and the like. The transfer device can be applied and applied.
In a color copying machine, after transferring to a tandem color image forming apparatus of a direct transfer system that sequentially transfers and superimposes a sheet (sheet) while being transferred by a transfer body, or after being transferred to an endless intermediate transfer belt as an intermediate transfer body, The present invention can be similarly applied to a tandem type image forming apparatus that batch-transfers to a sheet. Needless to say, the endless belt-like photoconductor can be similarly applied to a single image forming apparatus.

The present invention is not limited to an in-body discharge type image forming apparatus that discharges paper between an image forming unit and a scanner, for example, and an image in which paper is discharged to a paper discharge tray provided on a side portion of the image forming apparatus main body. You may apply also to a formation apparatus. In addition, a paper path fed from the paper feeding device 3 is formed in a substantially vertical direction (substantially vertically upward) toward the upper portion of the image forming apparatus main body 2. The present invention can also be applied to an image forming apparatus in which the conveyance path until the sheet is discharged to the sheet discharge tray is not substantially vertical (substantially vertical).
The present invention relates to a sheet conveying apparatus for conveying a sheet (paper) from a sheet storage means (paper feed tray) or a sheet stacking means (paper feed table) to a printing unit main body in a printing apparatus including a stencil printing machine. May also be applied.

In the copying machine 1 as the image forming apparatus described above, a document to be read is set manually, but an ADF (automatic document feeder) for automatically reading a plurality of documents (sheets) is provided. The sheet conveying apparatus of the present invention may be applied to the ADF in an equipped copying machine or printing apparatus.
Further, the image forming apparatus is not limited to a copying machine, but is a facsimile, a printer, an ink jet recording apparatus, a printing apparatus, an image reading apparatus mainly having an image reading function having a scanner for reading an image from a document, or the like. You may apply to the compound machine etc. which combined at least two of them. In any case, it is most suitable for equipment and devices that need to change the sheet conveyance direction while saving space on the sheet conveyance path, targeting a variety of sheet types as paper types. It can be set as a simple sheet conveying apparatus.

  The present invention is not limited to a sheet conveying device arranged in a plurality of paper feeding stages. For example, in the paper feeding device 3 shown in FIG. 1, the upper paper feeding tray 51 and the paper conveying device 5 ′ are removed, The present invention can also be applied to a sheet conveying apparatus including only a single sheet feeding tray 51 and a sheet conveying apparatus 5.

  As described above, the present invention has been described with respect to specific embodiments and modifications. However, the technical scope disclosed by the present invention is limited to those exemplified in the above-described embodiments and modifications. They may be configured by appropriately combining them. (For example, the above-described embodiments and modifications of the present invention may be combined as appropriate, or the above-described embodiments and modifications of the present invention may be combined first. The present invention can be applied to the first and second examples of the invention, etc.) Within the scope of the present invention, various embodiments, modifications, and examples can be configured according to the necessity and application. This will be apparent to those skilled in the art.

1 is a schematic front view showing an overall configuration of an image forming apparatus having a paper transport device to which the present invention is applied. FIG. 2 is an enlarged cross-sectional view of a main part showing an operation state in which the leading edge of the paper reaches a belt conveying unit, showing the paper conveying device of FIG. FIG. 4 is an enlarged cross-sectional view of a main part showing an operation state immediately before the leading edge of the paper reaches the nip portion of the second transport means in the paper transport device of FIG. 2. FIG. 3 is a simplified perspective view showing a drive mechanism in the paper conveying apparatus of FIG. 2. It is a schematic front view of the principal part of FIG. FIG. 3 is an enlarged cross-sectional view of a main part of a sheet conveying device for explaining a reference embodiment 1 ; It is a graph for demonstrating the test result regarding the dispersion | variation in the paper classification conveyance time in Reference Example 1. FIG. FIG. 3 is a cross-sectional view of a main part showing a paper transport device different from FIG. 2 to which the present invention is applied and a paper feed tray stage around the paper transport device. FIG. 9 is an enlarged cross-sectional view of a main part showing an operation state in which the leading edge of the paper reaches the belt conveyance means in the paper conveyance device of FIG. 8. FIG. 9 is an enlarged cross-sectional view of a main part showing an operation state immediately before the leading edge of the paper reaches the nip portion of the second transport means in the paper transport device of FIG. 8. It is sectional drawing of the principal part explaining the arrangement | positioning state of the 1st, 2nd conveyance means in the paper conveyance apparatus of a 1st reference example , its drive means, a sensor. It is a block diagram which shows the control structure in paper conveyance apparatuses, such as a 1st reference example . (A), (b), (c) is the front view of the principal part explaining the difference in the behavior which the front-end | tip of a thick paper and a thin paper hits a conveyance belt, (d) is an enlarged front view of (c). . It is a linear velocity diagram explaining the change state with the passage of time of the linear velocity before the turn and the belt linear velocity in the paper conveying apparatus of the first reference example . FIG. 10 is a linear velocity diagram illustrating a change state of the pre-turn linear velocity and the belt linear velocity over time in the paper conveyance device of the second reference example . (A), (b) is a linear velocity diagram explaining the change state with the passage of time of the linear velocity before the turn and the belt linear velocity in the paper conveying apparatus of the reference modification 1 of the first reference example . (A), (b) is a linear velocity diagram explaining the change state with the passage of time of the linear velocity before the turn and the belt linear velocity in the paper conveyance device of the reference modification 2 of the second reference example . FIG. 10 is an explanatory diagram of a main part for obtaining a conditional expression in which the leading edge of a sheet does not turn over in the sheet transport device according to the first and second embodiments . FIG. 6 is a linear velocity diagram illustrating a change state of the pre-turn linear velocity and the belt linear velocity over time in the paper conveyance device according to the first embodiment . FIG. 10 is a linear velocity diagram for explaining a change state of the pre-turn linear velocity and the belt linear velocity over time in the paper conveyance device according to the second embodiment . (A), (b), and (c) are based on the passage of time of the approach angle of the conveyance belt with respect to the conveyance surface in the sheet conveyance device according to Modification Example 1 of the first embodiment and Modification Example 2 of the second embodiment. FIG. 10 is an explanatory diagram of a main part for obtaining a conditional expression in which the leading edge of a sheet does not turn over when a change is taken into account. (A), (b) is a linear velocity diagram explaining the change state with the passage of time of the linear velocity before the turn and the belt linear velocity in the sheet conveying apparatus of the first modification of the first embodiment . (A), (b) is a linear velocity diagram explaining the change state of the linear velocity before turn and the belt linear velocity over time in the sheet conveying apparatus of the second modification of the second embodiment . FIG. 10 is a linear velocity diagram illustrating a change state of a pre-turn linear velocity and a belt linear velocity over time in a paper conveyance device according to a third embodiment . (A), (b) is a simplified front view for explaining an arrangement example of the first and second conveying means of the sheet conveying apparatus according to the difference in the sheet conveying path.

Explanation of symbols

1 Copying machine (image forming device)
2 Image forming apparatus body 3 Paper feed device 4 Document reading device 5A Paper transport device (sheet transport device)
6 1st conveyance means (1st conveyance means 6)
7 Second transport means (second transport means)
8 Belt conveying means (movement guide means)
9 Discharge tray 10 Photoconductor unit 10A Photoconductor 11 Fixing device 12 Developing device 13 Transfer device 21 Registration roller pair 29 First transport motor (drive means)
30 Second transport motor (drive means)
39 Paper linear velocity detection sensor (first linear velocity detection means)
40 Belt linear velocity detection sensor (second linear velocity detection means)
43 Control device (control means)
44 CPU (control structure of control means)
45 ROM (control structure of control means)
50 Bottom plate (sheet stacking means)
51 Paper feed tray (sheet storage means)
60 Pickup roller 61 Feed roller (one of the opposing pair of first conveying means 6)
62 Reverse roller (the other of the opposing pair of the first conveying means 6)
67 Manual feed tray 70 Conveyance guide member (inner side, guide member)
71 Conveying guide member (outer side, guide member)
72 Transport guide member (outer side of longitudinal transport path, guide member)
73 Conveying guide member (for forming the inlet from the paper feed tray to the conveying path)
79 Opening / Closing Guide (Sheet Conveyor Body)
80 Housing (sheet transport device main unit)
81 Grip roller (one of the opposite pair of the second conveying means, the rotation conveying driving means, the rotation conveying driving member)
81a Rotation drive shaft 82 of grip roller Conveying belt (belt as the other of the opposing pair of the second conveying means)
82a Conveying surface 83 of the conveying belt Pulley (constituting member of the belt conveying means as one of the opposed pairs of the first conveying means 6, first belt holding and rotating member)
83a Pulley shaft (downstream shaft of belt holding rotating member)
84 Pulley (constituting member of belt conveying means as one of the opposed pair of first conveying means 6, second belt holding rotating member)
84a Pulley shaft A 1st conveyance path (sheet conveyance path)
B Second transport path (sheet transport path)
R1 transport path R2 manual feed path R3 reverse transport path S paper (sheet / sheet-like recording medium, image forming medium)
Y Paper width direction (sheet width direction)
v Line speed before _one turn (first linear speed)
v ₂ belt linear velocity (second linear velocity)
t ₁ Time when the leading edge of the sheet contacts the conveying surface of the conveying belt t ₂ Time when the leading edge of the sheet starts to be nipped and conveyed to the nip portion of the second conveying means θ, θ ₀ entry angle θa Entry angle

Claims (16)

First conveying means for conveying the sheet at a first linear velocity;
A second transport disposed downstream of the first transport means in the sheet transport direction and transports the sheet transported by the first transport means in a sheet transport direction different from the sheet transport direction of the first transport means. Means,
At least the second transport unit of the first transport unit and the second transport unit is a sandwich transport unit that forms a sandwiching unit that sandwiches and transports the sheet,
Belt conveyance provided with a belt that is arranged in the outer direction of the sheet conveyance path formed between the first conveyance means and the second conveyance means, and conveys the sheet at the second linear velocity toward the clamping portion. Comprising means,
One of the linear velocity of the first linear velocity and the second linear velocity, Ri relatively variable der,
When the first linear velocity is v ₁ , the second linear velocity is v _2, and the entry angle of the leading end portion of the sheet with respect to the conveying surface of the belt is θ ₀ , the sheet has been conveyed by the first conveying means. Until after the front end of the sheet comes into contact with the conveyance surface of the belt and before it begins to be nipped and conveyed by the clamping unit,
A linear velocity satisfying the relational expression of v ₂ ≧ v ₁ / sin θ ₀ or v ₂ ≈v ₁ / sin θ ₀ ,
After the beginning of the sheet begins to be nipped and conveyed by the nipping unit,
A sheet conveying apparatus that conveys a sheet at a linear velocity satisfying a relational expression of v ₂ = v ₁ . First conveying means for conveying the sheet at a first linear velocity;
A second transport disposed downstream of the first transport means in the sheet transport direction and transports the sheet transported by the first transport means in a sheet transport direction different from the sheet transport direction of the first transport means. Means,
A first sheet conveying path formed between the first conveying means and the second conveying means;
A second sheet conveying path that is formed from upstream of the second conveying means to the second conveying means, and is different from the first sheet conveying path;
The first sheet conveyance path and the second sheet conveyance path have a merging conveyance path that merges upstream of the second conveyance means;
At least the second transport unit of the first transport unit and the second transport unit is a sandwich transport unit that forms a sandwiching unit that sandwiches and transports the sheet,
Belt conveying means provided with a belt that is arranged in an outer contour direction of the merging conveyance path and conveys a sheet at a second linear velocity toward the clamping unit;
One of the linear velocity of the first linear velocity and the second linear velocity, Ri relatively variable der,
When the first linear velocity is v ₁ , the second linear velocity is v _2, and the entry angle of the leading end portion of the sheet with respect to the conveying surface of the belt is θ ₀ , the sheet has been conveyed by the first conveying means. Until after the front end of the sheet comes into contact with the conveyance surface of the belt and before it begins to be nipped and conveyed by the clamping unit,
A linear velocity satisfying the relational expression of v ₂ ≧ v ₁ / sin θ ₀ or v ₂ ≈v ₁ / sin θ ₀ ,
After the beginning of the sheet begins to be nipped and conveyed by the nipping unit,
A sheet conveying apparatus that conveys a sheet at a linear velocity satisfying a relational expression of v ₂ = v ₁ . First conveying means for conveying the sheet at a first linear velocity;
A second transport disposed downstream of the first transport means in the sheet transport direction and transports the sheet transported by the first transport means in a sheet transport direction different from the sheet transport direction of the first transport means. Means,
At least the second transport unit of the first transport unit and the second transport unit is a sandwich transport unit that forms a sandwiching unit that sandwiches and transports the sheet,
Belt conveyance provided with a belt that is arranged in the outer direction of the sheet conveyance path formed between the first conveyance means and the second conveyance means, and conveys the sheet at the second linear velocity toward the clamping portion. Comprising means,
The linear velocity of either the first linear velocity or the second linear velocity is relatively variable,
When the first linear velocity is v ₁ , the second linear velocity is v _2, and the approach angle of the leading edge of the sheet with respect to the belt conveying surface is θ ₀ , the leading edge of the sheet is in contact with the conveying surface of the belt. Until before contact
A linear velocity satisfying the relational expression of v ₂ ≧ v ₁ / sin θ ₀ or v ₂ ≈v ₁ / sin θ ₀ ,
An arbitrary time after the leading edge of the sheet comes into contact with the belt conveyance surface is defined as t, and an approach angle that changes after time t is defined as θ, and is lowered from the center of the nipping portion of the first conveyance means to the belt conveyance surface. When the distance to the contact point between the perpendicular line and the conveying surface is 1, until the leading edge of the sheet comes into contact with the conveying surface of the belt and before it is nipped and conveyed by the clamping unit,
v ₂ ≧ v ₁ / sin θ or v ₂ ≈v ₁ / sin θ, where θ = cos ⁻¹ {1 / (v ₁ × t / l + 1 / cos θ ₀ )}
After the beginning of the sheet begins to be nipped and conveyed by the nipping unit,
v 2 ₌ v at a linear velocity which satisfies the relational expression _1, features and be Resid over preparative conveying device to convey the sheet. First conveying means for conveying the sheet at a first linear velocity;
A second transport disposed downstream of the first transport means in the sheet transport direction and transports the sheet transported by the first transport means in a sheet transport direction different from the sheet transport direction of the first transport means. Means,
A first sheet conveying path formed between the first conveying means and the second conveying means;
A second sheet conveying path that is formed from upstream of the second conveying means to the second conveying means, and is different from the first sheet conveying path;
The first sheet conveyance path and the second sheet conveyance path have a merging conveyance path that merges upstream of the second conveyance means;
At least the second transport unit of the first transport unit and the second transport unit is a sandwich transport unit that forms a sandwiching unit that sandwiches and transports the sheet,
Belt conveying means provided with a belt that is arranged in an outer contour direction of the merging conveyance path and conveys a sheet at a second linear velocity toward the clamping unit;
The linear velocity of either the first linear velocity or the second linear velocity is relatively variable,
When the first linear velocity is v ₁ , the second linear velocity is v _2, and the approach angle of the leading edge of the sheet with respect to the belt conveying surface is θ ₀ , the leading edge of the sheet is in contact with the conveying surface of the belt. Until before contact
A linear velocity satisfying the relational expression of v ₂ ≧ v ₁ / sin θ ₀ or v ₂ ≈v ₁ / sin θ ₀ ,
An arbitrary time after the leading edge of the sheet comes into contact with the belt conveyance surface is defined as t, and an approach angle that changes after time t is defined as θ, and is lowered from the center of the nipping portion of the first conveyance means to the belt conveyance surface. When the distance to the contact point between the perpendicular line and the conveying surface is 1, until the leading edge of the sheet comes into contact with the conveying surface of the belt and before it is nipped and conveyed by the clamping unit,
v ₂ ≧ v ₁ / sin θ or v ₂ ≈v ₁ / sin θ, where θ = cos ⁻¹ {1 / (v ₁ × t / l + 1 / cos θ ₀ )}
After the beginning of the sheet begins to be nipped and conveyed by the nipping unit,
v 2 ₌ v at a linear velocity which satisfies the relational expression _1, features and be Resid over preparative conveying device to convey the sheet. After the leading edge of the sheet conveyed by the first conveying means comes into contact with the conveying surface of the belt and before it begins to be nipped and conveyed by the clamping unit, the second linear velocity is the first linear velocity. The sheet is conveyed at a linear speed higher than the linear speed of 1,
Is hereinafter when the front end of the sheet began sandwiched and conveyed by the holding portions, one of claims 1 to 4 second linear velocity, characterized in that conveying the sheet at equal linear velocity and the first linear velocity The sheet conveying apparatus as described in any one .   The first line is kept constant from the time when the leading edge of the sheet conveyed by the first conveying means comes into contact with the conveying surface of the belt until before it is nipped and conveyed by the clamping unit. The sheet conveying apparatus according to any one of claims 1 to 5, wherein a speed is changed.   The sheet conveying apparatus according to claim 6, wherein the first linear velocity is changed so as to increase.   The first linear velocity is kept constant from the time when the leading edge of the sheet conveyed by the first conveying means comes into contact with the conveying surface of the belt until before the nipping / conveying operation starts, the second linear The sheet conveying apparatus according to any one of claims 1 to 5, wherein a speed is changed.   9. The sheet conveying apparatus according to claim 8, wherein the second linear velocity is changed so as to decelerate. The sheet conveying apparatus according to any one of claims 5 to 9, wherein the first linear velocity or the second linear velocity is continuously changed. Until the leading edge of the sheet conveyed by the first conveying means comes into contact with the conveying surface of the belt, the second linear velocity is conveyed at a linear velocity higher than the first linear velocity,
The first linear velocity is the second linear velocity after the leading edge of the sheet conveyed by the first conveying means comes into contact with the conveying surface of the belt and before it is nipped and conveyed by the clamping unit. The sheet is transported temporarily at a higher linear velocity than
Is hereinafter when the front end of the sheet began sandwiched and conveyed by the holding portions, one of claims 1 to 4 second linear velocity, characterized in that conveying the sheet at equal linear velocity and the first linear velocity The sheet conveying apparatus as described in any one .   12. The apparatus according to claim 1, further comprising at least one of a first linear velocity detecting means for detecting a first linear velocity and a second linear velocity detecting means for detecting a second linear velocity. The sheet conveying apparatus as described in any one.   The sheet conveying apparatus according to claim 1, wherein the sheet is a sheet having relatively high rigidity.   An image reading apparatus comprising the sheet conveying apparatus according to claim 1.   An image forming apparatus comprising the sheet conveying device according to claim 1 and / or the image reading device according to claim 14.   16. The image forming apparatus according to claim 15, wherein the image forming apparatus is any one of a copying machine, a facsimile machine, a printer, a printing machine, and an ink jet recording apparatus, or a complex machine that combines at least two of them. apparatus.

Images