JP4814113B2 - Sheet conveying apparatus and image forming apparatus - Google Patents

Description

The present invention is a sheet conveying equipment, a copying machine provided with a sheet conveying equipment of that, a facsimile, a printer, a printing machine, the image forming such as a complex machine that combines at least two of the ink jet recording instrumentation 置等 or their Relates to the device.

  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 load can be suppressed. 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. There is known a paper feeding device provided with a reversing guide member formed with an inclined surface that reaches the conveying means, and the reversing guide member is configured to move toward the second conveying means (for example, Patent Documents). 2).
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.

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.

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)

  Accordingly, the applicant of the present application disclosed an invention aimed at realizing and providing a novel sheet conveying apparatus and an image forming apparatus having the sheet conveying apparatus that can solve the problems of the prior art. This was proposed in Japanese Patent Application No. 2006-214779 dated May 7, etc. (hereinafter referred to as “prior application invention”). In the prior invention, a movement guide means (disposed in the outer direction of the sheet conveyance path formed between the first conveyance means and the second conveyance means, and moves and guides the sheet toward the second conveyance means ( Specifically, it is characterized by having a belt conveying means), and details of an example to which this is applied will be described later before an 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 transport device and / or an image reading device can be realized and provided.

However, it has been found that the following problems remain in putting the invention of the prior application into practical use. That is, thick paper, which is relatively stiff paper, can be transported from the feeding cassette of the apparatus main body to the image forming unit, but FIG. According to (A), it is shown that the transport time variation differs for each sheet thickness, particularly at a metric basis weight of 256 g / m ² . This indicates that the arrival time of the sheet to the image forming unit varies depending on the thickness of the sheet. When transporting thick paper having a metric basis weight of 256 g / m ² or more to the image forming unit, A sheet having a distance of less than metric basis weight 256 g / m ² between the conveyed sheet (hereinafter also referred to as “preceding sheet”) and the sheet conveyed subsequently (hereinafter also referred to as “following sheet”). sheet transport number per unit time to spread than when conveyed is reduced, operation rate of the device, i.e. ing in influencing productivity.
In its This, the present invention is primarily intended to provide to realize an image forming apparatus having the sheet conveying equipment which can solve the above problem, the sheet conveying equipment of it.

  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-described object, the invention according to each claim employs the following characteristic means and configuration.
According to the first aspect of the present invention, the first conveying unit that feeds the sheet in the sheet conveying direction from the sheet accommodating unit that accommodates the sheet , and the first conveying unit arranged on the downstream side in the sheet conveying direction, A second conveying unit that conveys the sheet conveyed by the first conveying unit in a sheet conveying direction different from the sheet conveying direction of the first conveying unit, and between the first conveying unit and the second conveying unit A sheet guide unit disposed in a contour direction of the sheet conveyance path to be formed and configured to move and guide the sheet toward the second conveyance unit, the sheet storage unit, the first conveyance unit, the movement guidance unit, and The second conveying means constitutes a sheet conveying unit that is detachable from the apparatus main body, unit detecting means for detecting that the sheet conveying unit is attached to the apparatus main body, and the unit detecting hand. Based on the output signal according to the sheet conveying unit installation from, and a second control means for changing the time until the feed started, feeding from the sheet accommodating means constituting said sheet accommodating means and said sheet conveying unit When the fed sheet is not a relatively high rigidity sheet, the time from the start of feeding a sheet to the start of feeding the next sheet is T1, and the sheet storage unit and the sheet transport unit are configured. When the sheet fed from the sheet storage means is a relatively rigid sheet, and T2 is the time from the start of feeding a sheet to the start of feeding the next sheet, T2 is The sheet conveying device is set earlier than T1.

  According to a second aspect of the present invention, in the sheet conveying apparatus according to the first aspect, the second conveyance after the sheet is fed when the sheet fed from the sheet storing means is not a relatively rigid sheet. The arrival time to the means is T3, and when the sheet fed from the sheet storage means is a relatively rigid sheet, the arrival time from the sheet feeding to the second conveying means is T4. In this case, T2 = T1- (T4-T3) is satisfied.

  According to a third aspect of the present invention, in the sheet conveying apparatus according to the first or second aspect, the first sheet conveying path formed between the first conveying means and the second conveying means, and the second conveying The second sheet conveying path formed from the upstream of the means to the second conveying means, which is different from the first sheet conveying path, and the first sheet conveying path and the second sheet conveying path are the second conveying. A merging / conveying path that merges upstream of the means, and the movement guide means is disposed in a contour direction of the merging / conveying path.

According to a fourth aspect of the present invention, in the sheet conveying device according to any one of the first to third aspects, the sheet having a relatively high rigidity has a metric basis weight of 256 g / m ² or more.

  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 temperature detection means for detecting the temperature inside the apparatus, and the output signal from the temperature detection means, And a first control means for changing T2.

  According to a sixth aspect of the present invention, in the sheet conveying apparatus according to any one of the first to fifth aspects, a sheet type detecting unit that detects a sheet type including a thickness of the sheet stored in the sheet storing unit. It is characterized by having.

  A seventh aspect of the present invention is the sheet conveying apparatus according to any one of the first to fifth aspects, further comprising a sheet type setting unit that sets a sheet type including a thickness of the sheet stored in the sheet storing unit. It is characterized by having.

According to an eighth aspect of the present invention, there is provided a first sheet conveying means for holding and conveying at least a belt conveying means in a direction different from a conveying direction of a sheet less than 256 g / m ² fed from the first sheet accommodating means. A second sheet conveying means for holding and conveying at least a belt conveying means in a direction different from the conveying direction of the sheet of 256 g / m ² or more fed from the second sheet accommodating means, The time from the start of feeding of the sheet in the first sheet storage means by the sheet transport means to the start of feeding of the next sheet is T1, and the sheet in the second sheet storage means by the second sheet transport means T2 is set earlier than T1 when the time from the start of feeding to the start of feeding the next sheet is defined as T2. That.

According to a ninth aspect of the present invention, there is provided an image forming apparatus comprising the sheet conveying device according to any one of the first to eighth aspects.

According to the present invention, novel sheet conveying equipment to solve the above problems, a copying machine provided with a sheet conveying equipment of that, a facsimile, a printer, a printing machine, an inkjet recording instrumentation 置等 or at least two of them It is possible to realize and provide an image forming apparatus such as a multifunction machine in which two are combined.
That is, according to the present invention, the basic effect of having a moving guide means, i.e. while a space and low cost, is excellent in sheet type such pairs refractory, for example a high sheet of relatively rigid cardboard or the like maintain more that also exhibits the fundamental effects that it is possible to feed and transport without problems original, even if the sheet type such are different, in particular the productivity even when the different thickness of the sheet can do.

The following are specific effects for each of the claimed inventions.
According to the first and fourth aspects of the invention, with the above configuration, it is possible to maintain productivity even when the sheet has different rigidity (for example, thick paper having a metric basis weight of 256 g / m ² or more). From the beginning, it is possible to eliminate the difference in productivity between the sheet conveying apparatus and the sheet conveying unit on the apparatus main body side, that is, for each sheet feeding unit.

According to the second and fourth aspects of the invention, with the above-described configuration, even a relatively high rigidity sheet (for example, a thick paper having a metric basis weight of 256 g / m ² or more) is not a relatively high rigidity sheet (for example, ordinary The same productivity as paper) can be ensured.

  According to the third aspect of the present invention, the above effect can be obtained even in the sheet conveying apparatus in which the movement guide means is disposed in the outer direction of the merging conveyance path between the first sheet conveyance path and the second sheet conveyance path. .

  According to the invention described in claim 5, the first control means is a sheet in which the sheet fed from the sheet storing means is relatively rigid based on an output signal from the temperature detection means for detecting the temperature inside the apparatus. By changing the time T2 from the start of feeding a sheet to the start of feeding the next sheet, the variation in environmental conditions (at least the temperature condition) may affect the waist of the sheet. , Can maintain productivity.

  According to the sixth aspect of the present invention, the sheet type detecting unit that detects the sheet type including the thickness of the sheet stored in the sheet storing unit automatically detects the sheet type including the sheet thickness. Therefore, the above feeding control for each sheet type including the thickness of the sheet can be easily realized without the user's trouble.

  According to the seventh aspect of the invention, the user can arbitrarily set the sheet type including the sheet thickness by including the sheet type setting unit that sets the sheet type including the thickness of the sheet stored in the sheet storage unit. Since it can be set, the feeding control for each sheet type including the thickness of the sheet can be easily realized.

According to the eighth aspect of the present invention, the above configuration can eliminate the difference in productivity for each of the first sheet conveying unit and the second sheet conveying unit, that is, for each sheet feeding unit.

According to the ninth aspect of the present invention, it is possible to realize and provide an image forming apparatus that exhibits the above-described effect by including the sheet conveying apparatus according to any one of the first to eighth aspects.

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", Example 1 is referred to as "Reference Example 1", the first embodiment is referred to as "First Reference Example", and a modification of the first embodiment. 1 is the “first embodiment”, the second modification of the first embodiment is the “first modification of the first embodiment”, and the third modification of the first embodiment is the “first embodiment”. Modified example 2 ”and the third embodiment are read as“ second reference example ”, respectively.

  FIGS. 4 to 17 described later including FIGS. 1 to 3 and the like include examples of a sheet conveying apparatus to which the invention of the prior application is applied and an image forming apparatus equipped with the sheet conveying apparatus. 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 registration roller pair 21 is arranged on the downstream side of the second conveying means 7 ′ and 7 in the paper conveying devices 5 ′ and 5 described later, and the paper conveyed from the second conveying means 7 ′ or 7 is placed at the same position. It functions as a registration unit that once stops and then re-transports to the image forming unit at a predetermined timing.

  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; It is mainly composed of a first conveyance path A as a curved first sheet conveyance path formed between the first conveyance means 6 and the second conveyance means 7.

  The sheet conveying device 5 is configured as a nipping / conveying means for nipping and conveying the sheet S by a pair of rotating conveying members with respect to the first conveying means 6 and the second conveying means 7. That is, the first conveying means 6 is configured as a first rotating conveying member pair composed of two oppositely arranged rotating conveying members, a feed roller 61 and a reverse roller 62, and the second conveying means 7 includes a grip roller 81 and a roller. The second rotation conveying member is composed of two rotation conveying members which are arranged opposite to each other with a conveying belt 82 stretched between a roller-like pulley 83 and a roller-like pulley 84. One of the pair is a belt transport provided with a transport belt 82 that moves and guides (transports) the paper S toward the nipping portion (nip portion) of the second transport means 7 while maintaining a state in contact with the leading edge of the paper S. The conveying surface 82a which is the means 8 (movement guide means) and which is a belt running surface formed on the conveying belt 82 in the belt conveying means 8 is disposed at a position deviated in the outline direction of the first conveying path A. It is characterized in that.

As described above, the paper conveyance direction of the first rotation conveyance member pair including the feed roller 61 and the reverse roller 62 and the paper conveyance direction of the second rotation conveyance member pair including the grip roller 81 and the conveyance belt 82 are: Different from each other, that is, the sheet conveyance direction of the first rotation conveyance member pair is set to a substantially horizontal direction which is the upper right direction in FIGS. 2 and 3, whereas the sheet conveyance of the second rotation conveyance member pair 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, in FIG. 4, 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 of the feed roller 61 and the reverse roller 62 (hereinafter “nip portion”). It is set in a 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 is the rotation center of the grip roller 81, the rotation center of the pulley 83, and the clamping part (hereinafter also referred to as “nip part”) 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 line segment connecting the three points with the center.

  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 belt conveying surface 82a 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 extends so as to substantially intersect the paper traveling direction. Has been.

As shown in FIGS. 3 and 4, the belt conveyance means 8 includes a conveyance belt 82, a grip roller 81 and a conveyance belt 82 for holding the conveyance belt 82 so as to be able to travel and winding the conveyance belt 82. The roller-like pulley 83 as the first belt holding and rotating member disposed to face the nip portion of the belt, and the pulley 83 facing the pulley 83 and upstream of the second conveying means 7 in the sheet conveying direction. It is mainly composed of the above-described roller-shaped pulley 84 as the second belt holding and rotating member. In the present example, a single example of the second belt holding and rotating member is shown.
The belt conveying unit 8 includes a belt conveying surface 82a (hereinafter referred to as “belt conveying”) in which the leading edge of the sheet S conveyed by the first conveying unit 6 excludes the conveying belt 82 portion held by the pulley 83 and the pulley 84. It is important to arrange it so as to come into contact with or contact the surface 82a ". 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 in contact with the belt conveying surface 82a is held without causing repulsion of the leading end of the sheet S, and the following effects can be obtained.
On the other hand, when the leading edge of the sheet S is disposed so as to be in contact with the portion of the conveyance belt 82 held by the pulley 83 and the pulley 84 of the conveyance belt 82, the conveyance belt 82 is brought into contact with the pulley 83 and the pulley 84. The held conveyance belt 82 portion is generally harder than the belly portion of the conveyance belt 82 and is less elastically displaced and deformed. Therefore, when the leading edge of the sheet S comes into contact with the above portion, the repulsion occurs. Or a stable and moderate 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. 4, the belt conveying means 8 is arranged such that the leading edge of the paper S conveyed by the first conveying means 6 enters with an acute rush angle θ with respect to the belt conveying surface 82a. That is also important. By disposing the belt conveying means 8 in this way, 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 reliably contacts the belt conveying surface 82a. This state is maintained, and the following effects can be obtained.
When the leading edge of the sheet S is arranged so as to enter the belt conveying surface 82a with a substantially perpendicular or right angle of incidence θ, the contact state of the leading end portion of the sheet S with the belt conveying surface 82a is unstable. For example, it is not preferable from the viewpoint of bending in the direction opposite to the traveling direction of the conveyor belt 82 or causing repulsion (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 rotary conveyance member of the second rotation conveyance member pair in the second conveyance 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 and holds the conveyance 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 open / close guide 79 is integrated (unitized) with a transport guide member 72 and a belt transport unit 8 which will be described later, and is configured as an open / close unit, such as a first transport path A and a vertical transport path extending substantially vertically upward. In order to make it easier for the user to handle paper jams, jams, etc., the conveyor belt 82 can be brought into and out of contact with the grip roller 81 around a hinge fulcrum shaft (not shown) below the housing 80. It is configured to be openable and closable.
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. Note that the opening / closing guide 79 shown in FIG. 3 and the like is compared with the opening / closing guide 79A shown in FIG. 17 of the example described later and provided with a belt conveying means 8A having a conveying belt 82 divided into a plurality of parts. Instead of the belt conveying means 8A, a belt provided with a conveying belt 82 that extends or is divided along the sheet width direction so as to be able to contact at least the entire area or both side edges of the sheet S in the sheet width direction to be used. The main difference is that the conveying means 8 is arranged.

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. More specifically, a biasing means (not shown) (see, for example, a compression spring 91 shown in FIG. 13 described later) is attached to a bearing member (not shown) (see, for example, a bearing 87 shown in FIG. 15 described later) that supports the pulley shaft 83a. As a result, the conveying belt 82 is urged in a direction in which it is pressed against the grip roller 81.
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.

A rotational drive source such as an electric motor provided exclusively for rotational driving of the grip roller 81 is connected to a rotational driving shaft 81a of the grip roller 81 via a driving force transmission means (not shown) such as a gear or a belt. They are connected (for example, see FIGS. 10 and 11 showing examples described later). 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.
If it is not necessary to have the same effect as the example described later with reference to FIGS. 10 and 11, for example, the drive system for driving the grip roller 81 is removed from the drive mechanism 22 to remove the grip roller 81. May be driven, and the conveyor belt 82 side may be driven by a drive mechanism (not shown).

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 conveying means 6 and the second conveying means 7 are constituted by the guide surface 70 a of the conveying guide member 70, the guide surface 71 a of the conveying guide member 71 facing the conveying guide member 70, and the conveying surface 82 a of the conveying belt 82. The 1st conveyance path A is formed between these.
In FIGS. 2 and 3, reference numeral 72 denotes a conveyance guide member provided at a position on the outer side of the vertical conveyance path substantially vertically upward starting from the second conveyance means 7, and has a predetermined gap with respect to the guide surface 70a. This is a conveyance guide member that includes a vertical conveyance guide surface 72a that faces and faces (opening interval) and guides the sheet S conveyed from the conveyance belt 82 to a conveyance path substantially vertically above. As described above, the vertical conveyance path that communicates with the conveyance path R1 is formed by the vertical conveyance guide surface 72a of the conveyance guide member 72 and the guide surface 70a of the conveyance guide member 70. Reference numeral 73 denotes a conveyance guide member that forms a sheet conveyance path from the sheet feed tray 51 to the nip portion between the feed roller 61 and the reverse roller 62, and that forms an introduction port for guiding and entering the sheet S in the nip portion. is there. 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. (The guide surface 70a) is provided, and the extent of the bulge is set such that the paper S is gently curved so that the leading edge of the paper S always reaches the belt conveyance surface 82a.

  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 downstream of the first transport path A. 2 to 3, the leading edge of the sheet S is guided and moved by traveling in the arrow direction of the conveying belt 82 while contacting the belt conveying surface 82 a, and the grip roller 81 and the conveying belt 82 are moved. , The paper S is nipped and conveyed by the grip roller 81 and the conveying belt 82 and further conveyed vertically upward, and finally the paper 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 82a and the paper surface is increased. 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 82a 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 defective conveyance of the paper S between the first and second conveying means 6 and 7 and to prevent the paper S from leading to the nip portion of the second conveying means 7. Can be reached.
On the other hand, since the belt conveying surface 82a extends continuously to the nip portion of the second conveying means 7 as it is, the leading end portion of the sheet S in contact with the belt conveying surface reaches the clamping portion reliably and smoothly and stably. It will be. In other words, even with a highly rigid paper S, the paper S is first conveyed by the first conveying means 6 while being gently curved to such an extent that the leading edge always comes into contact with the belt conveying surface 82a, and the leading edge of the paper S is conveyed by the belt. The leading edge of the sheet S is moved after obtaining a second conveying propulsion force that advances in the sheet conveying direction from the conveying surface 82a to the sheet S by active conveying guide action by the conveying surface 82a in contact with the surface 82a. The sheet S is bent more deeply so as to reach the holding portion of the second transport unit 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 82a, the conveyance driving force is replenished from the conveyance surface 82a to the sheet surface again, and the degree of curvature of the sheet S is gradually reduced, so that the sheet conveyance is continued. Can do. 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 the belt conveyance surface 82 a is the leading edge of the sheet S. It has a function as a movement guide unit that moves and guides the sheet S toward the second conveyance unit 7 while maintaining the contact state.
In this example, the belt conveyance means 8 as the movement guide means also has a function of moving and guiding the conveyance direction of the sheet S in the direction toward the nip portion of the second conveyance means 7 by the conveyance belt 82.

  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 3, and only a paper feeding device of “Imagio Neo453” manufactured by Ricoh Co., Ltd. is modified for testing. Machine (shown as “belt system” in Table 1) and a conventional paper conveying device (in FIGS. 1 to 3, the rotary conveying member facing 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 K6253 A type 40 degrees Friction coefficient of conveyance belt 82 to paper: 2.6
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. 4, a test for examining the variation (variation) in the conveyance time of each paper type was performed. FIG. 5 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. 4, 88 is a paper feed sensor that detects the leading edge of the paper S picked up by the pickup roller 60, and 89 is a second conveying means 7 (belt system) 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.
The drive systems of the first transport unit 6 and the second transport unit 7 (belt system) in the first embodiment are substantially the same as the drive mechanism 22 shown in FIGS. 10 and 11 described later in the fourth example. Is used. A driving system using a pair of grip rollers 81 and a roller-like pulley 83 (conventional method) in the first conveying unit 6 and the second conveying unit 7 ′ is compared with the belt-type driving mechanism 22 shown in FIGS. The main difference is that the conveying belt 82 and the roller-like pulley 84 are removed, and the roller-like pulley 83 is pressed and driven by the grip roller 81 as the driving roller.

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. 5 shows the variation result of the paper type conveyance time measured by the oscilloscope.

From the test results shown in FIG. 5, when the metric basis weight is 256 g / m ² or more as the paper type, the conventional method has a large variation in conveyance time (long conveyance time) and a large slip of the paper. In the belt method, it was found that the variation in the conveyance time is small (the conveyance time is not so long) and the slip of the paper is small. 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. 5 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 paper passing / conveying situation, when the metric basis weight is 256 g / m ² or more in the conventional method, the paper becomes stiff and difficult to bend along the curved paper conveying path. 1 to 4, it was found that the leading edge of the sheet hits a roller-like pulley 83 that is in contact with 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 belt transport surface 82a of the belt transport unit 8 via the first transport path A, the rigidity is high. Therefore, the various guide members constituting the first transport path A are changed to simple shapes so as to reduce the transport load resistance, or various guide members are not required at all. It turns out that it is also possible.
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 (which is straight ahead when compared to a sheet S having relatively high rigidity such as thick paper) and to guide and guide it to the belt conveyance surface 82a. In other words, the first transport path A is formed in order to make the leading edge of the paper S abut on the belly portion of the belt transport surface 82a 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.
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 K6253 A type 40 to 80 degrees.

  As described above, according to the paper conveyance device 5 and the copying machine 1 having the same shown in FIGS. 1 to 4, the paper type compatibility is achieved with a simple and low-cost device configuration while being compact and space-saving. A sheet conveying device and an image forming apparatus excellent in the above can be provided. 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 highly rigid paper type and is a paper conveyance device with excellent paper type compatibility. 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. Components and members that are the same as those of the sheet conveying device 5 shown in FIGS. Although not particularly described, the configuration not described in the present example, that is, the sheet conveying apparatus and other configurations and operations thereof are the same as those of the sheet conveying apparatus 5 of the first example and the first embodiment illustrated in FIGS. is there.

  The paper transport device 5 shown in FIGS. 6 to 8 is a first transport device 5 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 conveyance path A, the second conveyance path B is formed from the upstream of the second conveyance means 7 to the second conveyance means 7, and serves as another independent second sheet conveyance path different from the first conveyance path A. The point which has, the 1st conveyance path A and the 2nd conveyance path B have the confluence conveyance path | route (henceforth a "merging conveyance path" or a "merging part") which merges in the upstream of the 2nd conveyance means 7, The main difference is that one belt conveyance means 8 of the second rotation conveyance member pair is arranged so as to be dislocated in the outer direction of the merge conveyance path of the first and second conveyance paths A and B. The paper transport device 5 shown in FIGS. 6 to 8 is the same as the paper transport device 5 shown in FIGS. 1 to 4 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. Thus, the belt conveyance surface 82a is formed as a surface of the second conveyance path B in the outline direction. Accordingly, the leading edge of the sheet S conveyed on the first conveying path A by the first conveying means 6 always comes into contact with the belt conveying surface 82a and is conveyed on the second conveying path B by an unillustrated conveying means. The incoming paper S is not prevented from reaching the second conveying means 7.
The second conveyance path B is formed on the left side surface in the drawing of the conveyance guide member 72 with a predetermined opening interval facing the guide surface 71c and the guide surface 71c formed on the right side surface in the drawing of the conveyance guide member 71. It is formed by the guide surface 72a.

Next, the conveying operation of the sheet conveying device 5 shown in FIGS. 6 to 8 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. 7, 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 the conveyance belt. 82 abuts.
Since the conveyor belt 82 is traveling so as to travel in a substantially vertical upward (substantially above) direction indicated by an arrow a in FIG. 7, the leading edge of the sheet S that contacts the conveyor belt 82 is illustrated in FIG. As shown in FIG. 8, the sheet is conveyed to the nip portion between the grip roller 81 and the conveyance belt 82, and is nipped and conveyed to the downstream side in the substantially vertical direction by the pair of the grip roller 81 and the conveyance 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. 6 to 8, 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 4. 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.

(Third example)
A third example to which the invention of the prior application is applied will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the component and member same as a 2nd example, and description is abbreviate | omitted or simplified. Although not particularly described, the configuration not described in the third example, that is, the paper transport device and other configurations and operations thereof are the same as those of the paper transport device 5 of the second example shown in FIGS.

As shown in FIG. 9, when the trailing end Se of the sheet S curved at the time of conveyance deviates from the support by the conveyance guide member 71 or the like, the arrow shown in FIG. A splash phenomenon occurs in which the trailing edge Se of the sheet S moves in the b direction. In particular, in the case of a stiff, high-rigidity sheet S such as thick paper, the reaction force becomes large, and this sudden sound is a problem.
That is, in the transport process, the paper S is forcibly supported by at least two support points, and the rear end Se side of the paper S is the holding portion or guide of the first transport means 6 as one support point. When detached from the member 71 or the like, the trailing end Se of the sheet S is instantaneously collided with the belt conveyance surface 82a by the elastic return force of the curved sheet S supported only at the leading end side. The impact at that time increases as the rigidity of the paper S increases. For this reason, the sudden sound generated when the trailing edge Se of the paper S collides with the conveyor belt 82 due to the above-described splash phenomenon not only causes discomfort to the user, but also may cause misunderstanding that a failure has occurred. In other words, whether or not the device is malfunctioning because the above sudden sound occurs even if the paper is transported normally regardless of whether it is a normal paper S or a highly rigid paper S. There is a risk of giving such extra suspicion.

  Therefore, as shown in the figure, in the sheet conveying apparatus 5 of the third example, the belt conveying means 8 includes a pair of roller type pulleys 83 and 84 and a grip roller 81 on which the conveying belt 82 is stretched. A contact member such as a tension roller 85 as a member that contacts the other conveyance belt 82 is not arranged on the belt conveyance surface 82a side. Accordingly, the belt conveyance surface 82a side portion / location is given appropriate elasticity, and the impact caused by the trailing edge Se of the paper S is absorbed by the elastic action of the conveyance belt 82, so that high rigidity such as cardboard is obtained. Even when the paper S is transported, the paper transport device 5 that can ensure quietness is realized and provided.

  The tension roller 85 is formed in two linear portions formed on the conveyor belt 82 so as to be stretched around the pulley pairs 83 and 84, but not on the one conveying surface 82a side, and on the other opposite surface side portion. The roller 85 is pivotally supported at a position in contact with the peripheral surface so as to be displaceable outward from the position across the conveyor belt 82, and the roller 85 is pressed to the right in the drawing by a biasing member (not shown) and biased. Has been. As a result, the tension roller 85 is driven to rotate as the conveyor belt 82 travels, and is always in contact with the inner peripheral surface of the conveyor belt 82 so as to be displaced outwardly by receiving a predetermined urging force. A constant tension can be maintained without loosening 82 in the circumferential direction.

  Therefore, according to the paper transport device 5 of this example, the leading end side of the paper S in the paper transport direction is sandwiched and transported by the second transport means 7, and the rear end Se of the paper S is removed from the support by the guide member 71. Even when it collides with the belt conveyance surface 82a, it can be sufficiently elastically deformed so that the belt conveyance surface 82a is displaced in the collision direction as shown by a two-dot chain line in the figure. Since the impact can be absorbed, the magnitude of the sound generated by the collision can be reduced to suppress and mitigate the occurrence of abnormal noise as the operation sound of the paper transport device.

As described above, according to the sheet conveying apparatus 5 of the third example, the rear end Se of the conveyed sheet S contacts the belt 82 at a position different from the position where the trailing edge Se contacts the belt conveying surface 82a. Since the tension roller 85 as a supporting contact member is disposed, when the sheet S is conveyed with a predetermined curvature, the trailing edge Se of the sheet S is located at the nip portion of the first conveying unit 6. When any of the guide members 71 comes off and collides with the conveyance surface 82a, the collision belt 82 can be sufficiently elastically bent to absorb the impact, Sudden sound generated by a collision can be suppressed. That is, when the trailing edge Se of the sheet S is in contact with the belt conveyance surface 82a, the contact member does not hinder the deformation of the conveyance belt 82 where the trailing edge Se of the sheet S is in contact with the trailing edge Se of the sheet S. The conveyor belt 82 can be sufficiently bent in the contact direction.
In particular, when a highly rigid sheet S such as a thick sheet is conveyed, even if the trailing end Se of the sheet S in the sheet conveying direction comes into strong collision with the conveying belt 82, the impact due to the collision is conveyed to the conveying belt. 82 can be absorbed and relaxed by the elastic deformation of 82, and the generated impact sound can be sufficiently suppressed.
Therefore, as described above, sudden noises during paper conveyance can be suppressed, so that the user's discomfort is eliminated, and quietness that avoids the misconception that a failure has occurred is obtained, and the usability of the apparatus is improved. Can be made.

  On the other hand, when the leading edge of the sheet S first comes into contact with the belt conveying surface 82a as in the above-described sheet conveying process, even if no sudden sound is generated by the contact of the leading edge of the sheet S, a certain amount of conveyance is performed. Since elastic deformation of the belt 82 can be expected, the leading edge of the paper S can be brought into soft contact without causing it to rebound from the transport surface 82a, that is, repelling, and can be shifted to the state of contact as it is. Become. That is, with respect to the belt conveyance surface 82a that travels in the paper conveyance direction, the leading edge of the paper S conveyed by the first conveyance means 6 is slanted with respect to the conveyance surface 82a for the first time, and the entry angle θ (see FIG. 7). ), The direction in which the leading edge of the sheet S advances can be made to follow the conveying surface 82a without causing the leading edge of the sheet S to repel from the conveying surface 82a.

  The third example is not limited to the one shown in FIG. 9. For example, if the conveyance belt can be deformed to such an extent that sufficient silence can be obtained, the third example is arranged in a predetermined opposing manner as in the configuration shown in FIG. 9. Of the two substantially linear belt running surfaces that are stretched around the pair of pulleys 83 and 84 and formed on the conveying belt 82, the tension and tension are applied only to the non-conveying surface side that does not face the first conveying means 6. Without being limited to the arrangement of the roller 85, one of the two belt running surfaces including the facing conveying surface side is selected, and the roller is placed at any location on the selected belt running surface. May be arranged. That is, regardless of the rigidity strength in the thickness direction of the paper, the location where the trailing edge of the paper contacts the belt conveyance surface due to the above-described sag phenomenon is almost constant, and the belt deformation is allowed from the contact location. The roller may be arranged so that the tension roller is brought into contact with an appropriate place on the transport surface which is separated by a distance.

In the third example, the above-described predetermined position is secured, and a tension roller is provided for securing tension by pressing and urging outward from the inside of the stretched belt. On the other hand, a configuration may be provided in which a tension roller is provided to press and urge the belt inward from the outside to ensure tension.
In the case of this configuration, in addition to the function of imparting tension, a configuration may also be used in which a function of cleaning the outer peripheral surface of the belt is also used. According to the configuration of the tension roller that combines the tension imparting function for the belt and the cleaning function for the belt conveyance surface, the belt conveyance surface can be kept clean, which in turn improves the image quality. We can expect to contribute. That is, the belt conveyance surface can be kept clean, and the surface of the paper in contact with the belt conveyance surface can be similarly kept clean. In addition, a tension roller and a cleaning roller may be provided separately after securing the above predetermined position, and only a cleaning roller mainly having a cleaning function that does not have a tension applying function as a main function. It may be provided.

As described above, the second conveying means 7 of each paper conveying device 5 shown in FIGS. 1 to 4 and 6 to 9 is configured as a nipping and conveying means for nipping and conveying the paper S. That is, the second transport means 7 is a second rotational transport composed of two rotationally transported members arranged opposite to each other, a grip roller 81, a roller-shaped pulley 83, and a transport belt 82 stretched between the roller-shaped pulleys 84. Although it has been described as a member pair configuration, the grip roller 81 side is the driving side, and the conveying belt 82 side is described as the driven side that is driven in contact with the grip roller 81, but the drive / driven side is not necessarily defined. However, the technical contents include that the conveyance belt 82 side may be driven.
On the other hand, in the fourth example described below, the grip roller 81 side is defined as the driving side, and the conveying belt 82 side is defined as the driven side that is driven in contact with the grip roller 81 by the following contents. In the first embodiment, the grip roller 81 side is the driving side, and the conveyance belt 82 side is the driven side that is in contact with the grip roller 81 and is driven.

  Further, as described above, the conveyance belt 82 of each of the sheet conveyance devices 5 illustrated in FIGS. 1 to 4 and 6 to 9 has at least the maximum width of the conveyance belt 82 in the sheet width direction Y to be conveyed. As the belt width that is substantially the same as the paper width, that is, the belt width of the conveyance belt 82, a belt width that is at least equal to or larger than the maximum width of the paper to be conveyed is continuously set and secured. Similarly, the pulleys 83 and 84 over which the conveyance belt 82 is stretched and the grip roller 81 that is opposed to the conveyance belt 82 have pulleys and roller lengths in the paper width direction Y (axial longitudinal direction), and the belt width It is continuously formed to have a length equal to or longer than the length of. As a result, 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. . Along with this, it is possible to transmit the maximum possible force for the conveyance propulsion force that advances the paper S that can be supplied to the paper S from the conveyance belt 82 that is always moved in the conveyance direction in the conveyance direction. Is listed as a feature. In contrast, the fourth example is configured as follows.

(Fourth example)
A fourth example will be described with reference to FIGS. FIGS. 10 and 11 simply show the drive mechanism 22 as the feed drive means (paper feed drive system) of the first transport means 6 and the second transport means 7 in the paper transport apparatus 5A of the fourth example. Yes. 12 to 17 show details of the belt conveying unit 8A around the second conveying unit 7 in the paper conveying apparatus 5A of the fourth example.
A fourth example of the sheet conveying apparatus 5A shown in FIGS. 10 to 17 and the like is a second conveying unit that is a nipping and conveying means, as compared with the sheet conveying apparatus 5 shown in FIGS. 1 to 4 and FIGS. The belt conveying means 8A is used in place of the belt conveying means 8 and the point where the driving / following relationship of the means 7 is clarified so that the conveying belt 82 and the like are in contact with a part of the paper S in the paper width direction Y. The main difference is that it is configured intermittently in the paper width direction Y. The sheet conveying apparatus 5A of this example is the same as the sheet conveying apparatus 5 shown in FIGS. 1 to 4 and FIGS. 6 to 9 except for the differences described above.

  That is, the second conveying means 7 of the sheet conveying apparatus 5A is a rotating conveying driving means / rotating conveying driving member capable of transmitting a driving force by rotating one of the opposed pairs forming the nip portion as the clamping portion. And the other of the opposed pair is disposed in the outer direction of the paper conveyance path (first conveyance path A) formed between the first conveyance means 6 and the second conveyance means 7, A belt provided with a conveyance belt 82 that conveys (moves / guides) the sheet S toward the nip portion of the second conveyance unit 7 while rotating in direct contact with the roller 81 and holding the state in contact with the leading edge of the sheet S. It is characterized by comprising conveying means 8A (movement guide means).

  Further, the paper conveying apparatus 5A of the fourth example has a width of the conveying belt 82 that is greater than or equal to the maximum paper width to be conveyed as compared with the paper conveying apparatus 5 shown in FIGS. 1 to 4 and 6 to 9. And the lengths of the pulleys 83 and 84 and the grip roller 81 are each continuously formed in the paper width direction Y longer than the width of the conveying belt 82, The sheet width direction Y of the conveying belt 82 in the belt conveying unit 8A is in contact with a part of the leading edge of the sheet S in the sheet width direction Y (including the leading edge, the leading edge surface, and the corner / edge of the leading edge). It is characterized by being configured intermittently in the direction Y.

A plurality of grip rollers 81 are intermittently fixed and arranged on a rotational drive shaft 81a in the paper width direction Y in a skewered dumpling shape. On the other hand, the conveying belt 82 and the pulleys 83 and 84 of the belt conveying means 8A are disposed and arranged corresponding to at least one of the plurality of grip rollers 81 (that is, at least one of the opposed pairs). . Specifically, as shown in FIGS. 10, 15, and 17, three grip rollers 81 are arranged on the rotation drive shaft 81 a, and three grip rollers 81 correspond to and face the three grip rollers 81. The conveyor belt 82 is arranged with a width substantially equal to that of each grip roller 81. This detailed configuration will be described later.
In FIG. 10, in order to clearly show the drive mechanism 22, the arrangement interval of the grip rollers 81 is intentionally shifted in the direction of the rotation drive shaft 81 a, but is shown irregularly. Of course, it is arranged at intervals.

As shown in FIGS. 10 and 11, the drive mechanism 22 includes a paper feed motor 23 composed of a stepping motor as a single drive source / drive means, and a motor gear 24 fixed to the output shaft of the paper feed motor 23. The idler gear 25 meshed with the motor gear 24, the feed roller drive gear 61B meshed with the idler gear 25 and fixed to one end of the shaft 61a of the feed roller 61, the idler gear 26 meshed with the feed roller drive gear 61B, and the idler gear 26, and a feed roller gear 61A fixed to the other end of the shaft 61a near the feed roller 61, a feed roller gear 61A fixed to one end of the rotational drive shaft 81a of the grip roller 81, and the feed roller gear 61A. The above-described idler gear 65 that meshes with the roller gear 61A, and this Meshes with Idoragiya 65, 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, as illustrated in the first embodiment, the first conveyance path A is configured with a curvature portion having a relatively small curvature radius. For this reason, the sheet feeding motor 23 is single and serves as the driving means for the first conveying means 6 and the second conveying means 7 and contributes to the compactness of the apparatus.
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. 10, 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 4, the rotational drive relationship between the pickup roller 60 and the feed roller 61 has been described in a simplified manner. 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.

Next, with reference to FIGS. 12 to 17, a detailed configuration mainly on the belt conveying means 8 </ b> A side disposed facing the grip roller 81 will be described.
Compared with the belt conveying means 8 of the paper conveying device 5 shown in FIGS. 1 to 4 and FIGS. 6 to 9, the belt conveying means 8A of the paper conveying device 5A has a pulley 83 fixed on the pulley shaft 83a. Instead, the three pulleys 83 are rotatably supported on the pulley shaft 83b. Instead of the pulley 84 fixed on the pulley shaft 84a, the three pulleys 84 are rotatable on the pulley shaft 84b. Using a belt support member 86 as a support member that rotatably supports and supports the pulleys 83 and 84, a point that each pulley 83 and 84 is formed of a resin such as polyacetal resin, and the like. The main difference is that three pulley shafts 84b made of metal having a short length in the axial direction are used in place of the pulley shaft 84a that is long and continuous in the axial direction, and the features described later.

  As shown in FIG. 4, the grip roller 81 and the conveyor belt 82 are in contact with each other on a line connecting the center of the rotation drive shaft 81a of the grip roller 81 and the center of the pulley shaft 83b, as shown in FIG. A sandwiching portion (nip portion) is formed at a portion including the contact point. The pulleys 83 and 84 are made of, for example, a resin such as a polyacetal resin having good lubrication performance and wear resistance / durability, and the weight is reduced.

The conveyor belts 82 arranged at the three locations are the same except for the setting of a spring load, which will be described later, and will be described by taking one of them as a representative.
The conveyor belt 82 is rotated by the pulley shaft 84b and the pulley 83 rotatably supported by the pulley shaft 83b due to the assembly relationship of the pulleys 83 and 84 to the belt support member 86 via the pulley shafts 83b and 84b. It is suspended with a predetermined tension between the pulley 84 supported freely.
That is, the pulley shafts 83b and 84b are fixed and supported by the belt support member 86 so as to keep the distance between the shafts constant. At this time, the pulley shafts 83b and 84b are connected to the belt support member 86 so that the circumference of the conveyor belt 82 when the conveyor belt 82 is wound between the pulleys 83 and 84 is larger than the circumference of the conveyor belt 82 alone. It is also a feature point that it is arranged and supported in the case. With the above configuration, when the conveyor belt 82 is assembled on the belt support member 86 as the belt conveyor means 8A, the conveyor belt 82 is elastically adjusted so that the circumference after assembly is larger than the circumference of the conveyor belt 82 alone. It will be used by extending.

  Two bearings 87 are mounted on the pulley shaft 83 b between the three belt support members 86. A spring 91 as an urging unit pressurizes the pulley shaft 83b via a bearing 87, and generates a transport force for transporting the paper. As described above, the pulley shaft 83b and the pulley shaft 84b are fixed by the belt support member 86 so as to maintain a constant distance between the shafts, and the pulley shaft 84b is configured to be swingable about the pulley shaft 83b. ing.

The belt support member 86 is integrally formed of a resin such as polyacetal resin, and the weight is reduced. A spring pedestal 86 a that engages one end of the spring 92 is integrally formed on the back wall of the belt support member 86. Retaining rings for preventing the pulley shafts 83b and 84b from coming off are mounted in the vicinity of the pulley shafts 83b and 84b protruding from the belt support member 86.
As shown in FIG. 13, the rear surface of the belt support member 86 is urged between the spring base 86 a of the belt support member 86 and the spring receiving member 93 fixed to the open / close guide 79, thereby conveying the belt 82. A spring (compression spring) 92 is mounted as a biasing means that biases the grip roller 81 in such a direction as to always press against the grip roller 81 shown in FIG.

  As shown by hatching in FIG. 14, a positioning portion 86b for positioning the transport belt 82 at a predetermined position is integrally formed at the lower portion of the belt support member 86, and the positioning portion 86b is transported. By contacting the guide member 72, the position of the conveyance belt 82 itself is positioned. Further, as shown in FIGS. 13 and 16, the positioning portion 86 b and the conveyance guide member 72 are brought into contact with each other by the biasing force of the spring 92, whereby the conveyance belt 82 is positioned at a predetermined position. A belt protruding amount h from the conveyance guide rib 72b formed to protrude inward is ensured.

As shown in detail in FIG. 16, the bearing 87 is formed with a U-shaped groove 87a, and the pulley shaft 83b is loosely fitted to the U-shaped groove 87a, so that the pulley shaft 83b is urged by the urging force of the spring 91. The conveying belt 82 is urged and pressurized in a direction in which the conveying belt 82 is pressed against the grip roller 81. The position of the pulley shaft 83b is fixed when the conveying belt 82 is brought into pressure contact with the grip roller 81, but the pulley shaft 84b is configured to be swingable in the direction of the arrow shown in FIG. 14 about the pulley shaft 83b. .
Referring to FIGS. 13 and 16, it has been described above that one end of the spring 92 presses the belt support member 86, but the other end is supported and locked by the spring pressurizing table 94. The spring pressing base 94 is configured to be movable and fixed at an arbitrary position with respect to a slit 93a formed in the spring receiving member 93 along the direction of the urging force of the spring 92. In the figure, an example of fastening and fixing with screws is shown. With this configuration, the spring load as an urging force of the spring 92, that is, the applied pressure can be changed by arbitrarily changing the compression length of the spring 92 at three locations. In the example of the present embodiment, the same spring specifications such as the spring load, spring length, and shape of the two springs 91 are used. Similarly, the same spring specifications such as spring load, spring length, and shape of the three springs 92 are used.

  Although description will be omitted, as shown in FIGS. 17A and 17B, the configuration of the main body side of the paper feeding device 3 is divided into the first conveyance path A, as in a general conventional paper feeding device. Then, with respect to the apparatus main body 78 provided with the housing 80 and the like shown in FIGS. 3, 4 and 7 to 9, the hinge fulcrum shaft 76 provided at the lower part of the apparatus main body 78 is used as a swing fulcrum. The open / close guide 79 as the open / close unit is configured to be openable / closable in the directions of arrows C and D in FIG. With such an open / close configuration, the jammed paper (jam paper) is removed.

  As described above, the conveying belt 82 of the belt conveying means 8A in this example has a pair of roller-like pulleys 83 depending on the assembly of the pulleys 83, 84 to the belt support member 86 via the pulley shafts 83b, 84b. , 84 with a predetermined tension. The conveyor belt 82 is pressed against a grip roller 81 driven by a pulley 83 provided to be freely rotatable by an urging force of a spring 92, and is driven to rotate as the grip roller 81 rotates.

  Therefore, according to the fourth example, the following advantages and effects are achieved. First, since the conveyance belt 82 of the belt conveyance means 8A is configured to rotate directly in 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 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.

Secondly, the pulleys 83 and 84 (first and second belt holding and rotating members) are pivotally supported by a belt supporting member 86 (supporting member) so as to keep the distance between the shafts constant. The pulley shafts 83b and 84b of the pulleys 83 and 84 are arranged such that the circumference of the conveyor belt 82 when the conveyor belt 82 made of an elastic member is wound between the pulleys 83 and 84 is larger than the circumference of the conveyor belt 82 alone. In this example, as a means for applying a belt tension, a belt tensioning mechanism or a mechanism called a tie toner, which is commonly used, is not provided as a means for applying a belt tension, and the conveyor belt 82 is a biaxial pulley. Since it is configured to elastically extend between the spaces 83 and 84 and apply tension, it is simpler than the conventional configuration in which a mechanism such as a tensioner is provided. Space-saving, low cost can be realized.
As a result, in the paper transport apparatus that can improve the transport performance of relatively stiff paper such as thick paper in the turn section of the first transport path A, the mechanism is simple, and space saving and cost reduction can be realized. In addition, the effects described in the column of the effects of the invention described above are also exhibited.

(First embodiment)
The first embodiment will be described with reference to FIGS. 18 and 19. The first embodiment shown in FIGS. 18 and 19 is more rigid than the paper conveying device 5A of the fourth example shown in FIGS. 10 to 17 and the copier 1 (see FIG. 1) having the same. The main difference is that a control configuration is added that can appropriately maintain the sheet interval when different sheets are used. That is, the only difference is that the control configuration capable of executing the control operation described below is a sheet conveying apparatus 5A added to the sheet conveying apparatus 5A of the fourth example shown in FIGS. Configurations and operations other than the above differences are the same as those of the fourth example of the sheet conveying apparatus 5A and the copying machine 1 having the same shown in FIGS.

FIG. 18 shows a main control configuration around the sheet conveying device 5A of the present embodiment. The control configuration shown in FIG. 18 is common except for a part of devices and sensors connected in the embodiments and modifications described later, and is stored in the control / calculation function of the CPU 44 in the control device 43, the ROM 45, and the like. The operation program and the related data are only partially different.
The control device 43 performs feeding (hereinafter referred to as “paper feeding”) mainly related to the start / stop timing of the paper feeding motor 23 in relation to the paper spacing between the preceding paper and the following paper (hereinafter also referred to as “paper spacing”). (Also called) to control the start time. 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 sheet conveying device 5A and the like in 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 paper 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 paper feeding device 3 (hereinafter, modifications 1 to 3 and second to be described later). The same applies to the above embodiment).

A control device 43 as a control means 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, and a timer 48. And a microcomputer having a configuration in which they are connected by a signal bus.
The CPU 44, via the input port, sensor input circuit, and the like, includes a paper feed sensor 88, a vertical conveyance sensor 89, a thickness detection sensor 96, and the start switch and various keys (not shown) of the operation panel 95 as an operation unit. And are electrically connected.

The sheet feeding sensor 88 and the vertical conveyance sensor 89 detect the arrival time by using the arrival time from when the sheet from the sheet feeding tray 51 serving as the sheet storage unit is fed until it reaches the second conveyance unit 7. It has a function as a means. This arrival time is the time from when the leading edge of the paper is detected to be ON by the paper feed sensor 88 to when it is detected to be ON by the vertical conveyance sensor 89, by a timer 48 as a time measuring means that is also an internal timer of the control device 43. This is what the CPU 44 recognizes.
The thickness detection sensor 96 has a function as a sheet type detection unit that detects a paper type (sheet type) that is a paper type including the thickness of the paper. In this embodiment, the thickness detection sensor 96 detects the thickness of the paper. Detect paper type. As a specific example of the thickness detection sensor 96, for example, a known sensor that detects the thickness of a sheet by detecting the amount of light that passes through the sheet when laser light is projected onto the sheet is used.

  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. A high-rigidity sheet (high-rigidity sheet) (not shown) that generates and generates a signal for feeding and conveying the sheet by selecting and setting (for example, the sheet conveyance device 5A in place of the sheet feeding tray 51 and the sheet conveyance device 5 in FIG. 1) ) Selection key (hereinafter also referred to as “thick paper selection key”), and a paper feed stage (for example, the paper feed tray 51 of FIG. A low-rigidity original selection key (hereinafter also referred to as a “plain paper selection key”), a thin paper selection key, etc. for selecting and setting the paper conveyance device 5 ′) and generating a signal for feeding and conveying the paper S are arranged. It is installed. The thick paper selection key, the plain paper selection key, and the thin paper selection key have a function as sheet type setting means for setting the paper type including the thickness of the paper stored in the paper feed tray 51 as the sheet storage means.

The CPU 44 is electrically connected to the paper feed motor 23 composed of a stepping motor via the output port and a motor drive circuit (not shown), and transmits a command signal for controlling the drive of the motor 23 to the motor drive circuit. . In the present embodiment, the drive / stop timing of the paper feed motor 23 is controlled under the condition that the rotation speed of the paper feed motor 23 is constant, that is, the paper transport speed of the first and second transport means 6 and 7 is constant. The
The RAM 46 temporarily stores the calculation result in the CPU 44, and from the thick paper selection key, the plain paper selection key, the thin paper selection key, the paper feed sensor 88, the vertical conveyance sensor 89, the thickness detection sensor 96, etc. of the operation panel 95. Output signals are input / output by storing output signals as needed.
In the ROM 45, “Relational data for changing the start / stop timing of the paper feed motor 23 and the paper feed start time via the motor drive circuit” for the CPU 44 to perform the control function described above, “paper thickness Data table related to transport time for each (paper type), “relevant data on the number of pulses supplied to the paper feed motor 23 via the motor drive circuit”, “relevant data on the above-described relational expressions, etc.” are stored and stored in advance. Has been.

Next, the operation will be described. For example, a sheet having a metric basis weight of less than 256 g / m ² (hereinafter also simply referred to as “256 g / m ² ”) that is not a relatively high-stiff sheet is fed from the lower feed tray 51 in FIG. In the case of conveyance, when the belt conveyance means 8 (or 8A) as the movement guide means proposed in the above-mentioned prior application is used, almost the same conveyance time regardless of the difference in metric basis weight, that is, the thickness of the paper. It is clear from the variation contents of the conveyance time in FIG. 5 described as the first embodiment. Accordingly, in order to improve the productivity by reducing the paper interval between the trailing edge of the preceding paper and the leading edge of the succeeding paper when the paper is continuously conveyed, the leading paper is started after the feeding is started. Control is performed so that feeding of the next succeeding sheet starts after a predetermined time T1 after the trailing edge of the sheet passes through the vertical conveyance sensor 89 shown in FIG.
At this time, the preceding sheet is temporarily stopped in order to correct the sheet skew or the like (registration correction) by the registration roller pair 21. Then, at the transfer position in the transfer device 13 shown in FIG. 1, control is performed so that the sheet is transported at a process speed (slower than the paper feed speed).
Therefore, T1 is a necessary condition that the predetermined paper feed start time T1 is such that the succeeding paper does not come into contact with the preceding paper. Hereinafter, in the present embodiment, for ease of understanding of the present invention, for convenience of explanation, a sheet of less than 256 g / m ² that is not a relatively high rigidity sheet is referred to as “plain paper”, for example, and a relatively high rigidity sheet. For example, a sheet of 256 g / m ² or more will be described as “thick paper”.

Here, as is clear from FIG. 5 of Example 1, a sheet of less than 256 g / m ² (for example, “plain paper” in the present embodiment) and a sheet of 256 g / m ² or more which is a relatively high rigidity sheet. (In this embodiment, for example, “thick paper”), there is a variation in the transport time from the paper feed sensor 88 to the vertical transport sensor 89. Then, even if it is possible to continuously transport a sheet of 256 g / m ² or more by the belt transport unit 8 of the first embodiment, the transport time from the paper feed sensor 88 to the vertical transport sensor 89 is 256 g / m ^2. Therefore, when the feeding of the succeeding paper is started at the paper interval of the same time T1 as described above, the paper interval is larger than when the paper having a paper size of less than 256 g / m ² is transported. As a result, the number of sheets transported per unit time decreases, and the operating rate of the apparatus, that is, productivity decreases.

Therefore, in this embodiment, as shown in FIG. 19, when continuously feeding thick paper of 256 g / m ² or more, the feeding start time T2 at which the succeeding paper does not come into contact with the preceding paper is set to 256 g / m. ^When continuously feeding less than ² sheets, it is set shorter than the feed start time T1 so that the succeeding sheet does not contact the preceding sheet, and the data is stored in the ROM 45 in advance (T1> T2, Step S1 to step S3).
The time T2 is the arrival time T3 is a conveyance time from the sheet feeding sensor 88 to the vertical conveyance sensor 89 at the time of conveying plain paper of less than 256 g / ^{m 2,} definitive when transporting the 256 g / ^{m 2} or more cardboard The difference from the arrival time T4, which is the conveyance time from the paper feed sensor 88 to the vertical conveyance sensor 89, is the time subtracted from T1. That is, the present embodiment is characterized in that the feed motor 23 is driven and controlled by the control device 43 so that T1> T2 and T2 = T1- (T4-T3) are satisfied.

  Therefore, according to the present embodiment, the time from the start of paper feed to paper discharge is slower for thick paper than for plain paper, but the paper feed start time for subsequent paper is earlier than that for plain paper. By doing so, it is possible to control so that the paper interval between the preceding paper and the following paper is substantially the same as that of the plain paper. As a result, it is possible to secure and achieve the same productivity as that of plain paper even when continuously feeding thick paper with different paper thickness due to different paper types.

  The control according to the first embodiment is not limited to being applied to the sheet conveying apparatus 5A of the fourth example illustrated in FIGS. 10 to 17, and for example, the configuration of the drive mechanism 22 illustrated in FIGS. 10 and 11. By clarifying, the first example shown in FIGS. 1 to 4, the first example shown in FIG. 5, the second example shown in FIGS. 6 to 8, and the third example shown in FIG. 9. Needless to say, the present invention can also be applied to the sheet conveying apparatus 5 provided with the belt conveying means 8 (hereinafter, the same applies to modified examples 1 to 3 described later and the second embodiment).

In the first embodiment, the control of changing the paper feed start time between plain paper and thick paper in the paper transport device 5A provided with the belt transport means 8A as the movement guide means has been described. However, the present invention is not limited to this form. Absent.
For example, a plurality of paper feed units, one of which is a second transport unit 7 including a belt transport unit 8A as a movement guide unit, and the other paper feed units are the first and second conventional paper feed units. When the second conveying means 6 and 7 ′ are selected, the sheet feeding start time T2 by the belt conveying means 8A may be calculated and controlled as follows. In this case, the arrival time of plain paper by the conventional first and second conveying means 6, 7 'is T3, the arrival time by the belt conveying means 8A is T4, and the conventional first and second conveying means 6, 7' means A paper feed start time at which the succeeding paper (plain paper) does not contact the preceding paper is T1, and the paper feed start time T2 is a time obtained by subtracting the difference between T4 and T3 from T1, that is, T2 = T1− (T4). -T3) is controlled so as to satisfy the relationship. In the case where the sheet feeding units are stacked in the vertical direction, the sheet conveyance distance from each sheet feeding unit to the registration roller pair 21 is different.

(Modification 1 of the first embodiment)
With reference to FIGS. 20-21, the modification 1 of 1st Embodiment is demonstrated. In the first modification, as shown in FIG. 21A, compared with the control configuration of the first embodiment shown in FIGS. 18 and 19, for example, the fourth example shown in FIGS. The same thing as the sheet conveying apparatus 5A constitutes an additional unit 5AB as a sheet conveying unit that is detachable from the apparatus main body of the sheet feeding apparatus 3, and the additional unit 5AB is used as the apparatus main body of the sheet feeding apparatus 3. The additional unit detection sensor 98 is newly used as a unit detection means for detecting that it is attached, and the additional unit detection sensor 98 is electrically connected to the CPU 44 via the input port and the sensor input circuit. And a second sheet feeding start time T2, which is a time until the feeding of the thick paper is started, based on the output signal relating to the mounting of the additional unit 5AB from the additional unit detection sensor 98. That it uses a control device 43 shown in FIG. 20 as control means it differs mainly. The control configuration of Modification 1 is the same as the control configuration of the first embodiment shown in FIGS. 18 and 19 except for the above differences.

As shown in FIG. 21A, the additional unit 5AB is also called an additional paper cassette to be added later or a paper feed stage to be retrofitted. The paper transport device 5A originally present in the main body of the paper feeder 3 is used. Is configured as a main unit 5AA (substantially the same as the sheet conveying device 5A, to which an additional unit 5AB is coupled), and is configured to be detachable via fastening and coupling means such as screws. ing.
For example, when the additional unit 5AB is coupled to the main body unit 5AA, the additional unit detection sensor 98 is electrically connected by connecting female and male connectors that combine signal lines of the sensor and power lines of the paper feed motor 23 and the like. Represents the simplest sensor that can be detected. Of course, it goes without saying that a dedicated sensor for detecting the attachment / detachment state of the additional unit 5AB with respect to the main unit 5AA may be provided.
The control device 43 shown in FIG. 20 is a time for supplying the thick paper to the control device 43 shown in FIG. 18 based on the output signal related to the attachment of the additional unit 5AB from the additional unit detection sensor 98. The only difference is that a function as a second control means for changing the paper start time T2 is newly added.

In this modification, as shown in FIG. 21, first, it is determined by the additional unit detection sensor 98 whether or not the additional unit 5AB is mounted on the main unit 5AA, that is, whether or not the additional unit 5AB has been detected (step). S5). If it is detected that the additional unit 5AB is attached to the main unit 5AA, the process proceeds to step S6, and it is determined whether the sheet fed from the additional unit 5AB is a thick sheet of 256 g / m ² or more. When the plain paper is less than / m ^{2, the} feed start time T1 related to the plain paper set on the main unit 5AA side is extracted from the ROM 45, and the plain paper is continuously fed at the feed start time T1. (Steps S6 to S8).
On the other hand, if it is determined in step S6 that the paper fed from the additional unit 5AB is a thick paper of 256 g / m ² or more, the paper feed start time T2 related to the thick paper is extracted from the ROM 45, and is shown in FIG. As in step S1 and step S3 in the first embodiment, thick paper is continuously fed at the feed start time T2 (<T1) (steps S9 to S10).
Therefore, according to the present modification, the same effects as those of the first embodiment can be obtained, and the productivity of each additional unit 5AB added to or added to the main unit 5AA, in other words, the productivity of each sheet feeding unit. Can eliminate the difference.

(Modification 2 of the first embodiment)
With reference to FIGS. 22-24, the modification 2 of 1st Embodiment is demonstrated. In the second modification, a temperature / humidity sensor 97 (temperature / humidity detection means) as temperature detection means for detecting at least the temperature inside the apparatus is compared with the control configuration of the first embodiment shown in FIGS. Based on the temperature / humidity data from the temperature / humidity sensor 97, the temperature / humidity sensor 97 is newly connected to the CPU 44 via the input port and the sensor input circuit, and the like. The main difference is that a function capable of executing the control described later for changing the paper feed start time T2, which is the time until the start of feeding thick paper, is added. The control configuration of Modification 2 is the same as the control configuration of the first embodiment except for the above differences.

FIG. 23 shows three environmental (temperature / humidity) conditions, that is, 23 ° C. and 50% indicated by reference sign MM (corresponding to normal temperature in FIG. 24) and reference sign LL in the paper transfer device 5A equipped with the belt transfer means 8A. For each paper type, using three parameters of temperature and relative humidity of 10% 15% (corresponding to a low temperature in FIG. 24) and 27% 80% (refer to whether or not corresponding to normal temperature in FIG. 24) indicated by symbol HH. The comparison test result of the change of the conveyance time is shown. In the figure, the horizontal axis represents the metric basis weight (g / m ² ) related to the paper type, and the vertical axis represents the conveyance time (ms).
In FIG. 23, 280 g / m ² (T) on the horizontal axis is the vertical eye of the same paper, 280 g / m ² (Y) is the horizontal eye of the paper, T6200 is a paper having a metric basis weight of 69 g / m ² , 180K Represents a paper having a metric basis weight of 209 g / m ² . Further, the strip-shaped thick bar graph on the horizontal axis represents the average value of the transport time, and the thin bar graph represents the variation in the transport time.

From the graph shown in FIG. 23, it can be seen that when the paper exceeds 280 g / m ² (T: vertical mesh), the transport time varies greatly depending on the environmental conditions. It can also be seen that, especially at low temperatures, the paper becomes stiff and difficult to transport compared to other environments.
Therefore, if the transport time varies as described above due to the environmental conditions of the copier equipped with the installed paper transport device 5A, the productivity varies. Or, if the paper feed start time T2 for thick paper is set based on the low temperature condition, the paper transport time will be shortened under other environmental conditions, and the subsequent paper will collide with the preceding paper. , Jam will occur.
Therefore, in this modification, for example, the temperature / humidity inside the apparatus is detected by the temperature / humidity sensor 97 attached near the back surface of the fixing device 11, and the paper feed start time T2 can be controlled / changed based on the detection result. Configured.

In addition to the function of the first embodiment, the control device 43 of the present modification shown in FIG. 22 has a temperature from the temperature / humidity sensor 97 compared to that of the first embodiment shown in FIG. A function as a first control means for changing the paper feed start time T2 is added based on an output signal related to humidity data, and the ROM 45 has various environmental conditions corresponding to the thickness of each paper. The main difference is that data of transport times T4 and T10 which are arrival times from the paper feed sensor 88 to the vertical transport sensor 89 and the paper feed start time T2 at that time are stored.
The ROM 45 is not limited to this, and may be an external memory, or may be configured by, for example, EPROM or flash memory capable of rewriting T4 and T2 in accordance with the operation history of the apparatus, or changed by replacing the ROM chip. It may be possible. This also applies to the ROM 45 shown in FIGS. The temperature / humidity sensor 97 is not limited to this. For example, the temperature / humidity sensor 97 may periodically detect at least the temperature around the apparatus from when the apparatus is turned on or during an image forming operation.

With reference to FIG. 24, the control operation of this modification example under the above environmental conditions will be described in some detail. First, when the start signal of the image forming operation is input by pressing the start switch of the operation panel 95, the temperature / humidity sensor 97 detects the temperature / humidity around the apparatus. The controller 43 determines whether the temperature at that time corresponds to one of low temperature, normal temperature, and high temperature. Next, whether the paper stored in the paper feed tray 51 of each paper feed stage is thick paper or plain paper is detected by the thick paper selection key, the plain paper selection key, or the like on the operation panel 95 or the thickness detection sensor 97. Therefore, the CPU 44 determines whether the paper is thick paper or plain paper based on the detection result (step S15).
Then, the CPU 44 compares and judges the sheet thickness and which sheet feed start time T2 stored in the ROM 45 corresponds to the sheet thickness, and determines T2 appropriate for the above condition. By the way, when the temperature and humidity are low and low humidity (LL) conditions, the paper feed start time is set to the shortest T10, and when the temperature and humidity is normal temperature (MM) conditions or high temperature (HH) conditions, the paper feed start time is set. Set to T2 (steps S17 to S21).

  Therefore, according to this modification, even when the environmental strength including temperature and humidity affects the stiffness of the paper, the paper feed start time can be changed for each environmental condition, that is, the paper transport time can be changed. By doing so, it is possible to provide a paper transport device that maintains productivity and does not reduce productivity.

(Modification 3 of the first embodiment)
A modification 3 of the first embodiment will be described with reference to FIGS. 25 and 26. Modification 3 is characterized in that it has a control configuration in which Modification 1 shown in FIGS. 20 and 21 and Modification 2 shown in FIGS. 22 to 24 are combined.
The control configuration of Modification 3 shown in FIG. 25 and the control operation shown in FIG. 26 can be understood and implemented by those skilled in the art from Modifications 1 and 2 described above. A brief explanation will be given.

As shown in FIG. 26, first, it is determined by the additional unit detection sensor 98 whether or not the additional unit 5AB has been mounted and detected on the main unit 5AA (step S25). If it is detected that the additional unit 5AB is attached to the main unit 5AA, the process proceeds to step S26, where it is determined whether the sheet fed from the additional unit 5AB is a thick sheet of 256 g / m ² or more. When the plain paper is less than / m ^{2, the} feed start time T1 related to the plain paper set on the main unit 5AA side is extracted from the ROM 45, and the plain paper is continuously fed at the feed start time T1. (Steps S26 to S28).
On the other hand, in step S26, the paper stored in the paper feed tray of the additional unit 5AB is thick paper of 256 g / m ² or more by the thick paper selection key, the plain paper selection key or the like of the operation panel 95 or the thickness detection sensor 97. If it is determined, the process proceeds to step S29, and the CPU 44 compares and determines the sheet thickness and which sheet feed start time T2 stored in the ROM 45 corresponds to the above-mentioned conditions. Determine the appropriate T2. By the way, when the temperature and humidity are low and low humidity (LL) conditions, the paper feed start time is set to the shortest T10, and when the temperature and humidity is normal temperature (MM) conditions or high temperature (HH) conditions, the paper feed start time is set. T2 is set (steps S29 to S36).
Therefore, according to this modification, the effects of Modifications 1 and 2 are achieved.

(Second Embodiment)
With reference to FIGS. 27 and 28, the second embodiment will be described. The second embodiment replaces the paper feeding device 3 as compared with the copier 1 having the paper feeding device 3 having the paper conveying device 5A and the like shown in FIGS. 10 to 17 of the first embodiment. 18A and 18B, the sheet feeding device 3A composed of the first sheet conveying device 5C and the second sheet conveying device 5B configured by a plurality of sheet feeding stages (two stages in this example) in the substantially vertical direction is used. 28 as a control means for controlling the paper feeding operation of the first paper transport device 5C and the second paper transport device 5B, instead of the control configuration around the control device 43 of the first embodiment shown in FIG. The main difference is that a control configuration around 43A is used. That is, in the second embodiment, except for the control configuration around the sheet feeding device 3A shown in FIG. 27 and the control device 43A shown in FIG. 28, the sheet conveying device 5A shown in FIGS. This is the same as the copying machine 1 provided with the paper feeding device 3 provided with.

The first paper transport device 5C transports at least a belt in a direction different from the transport direction of paper (for example, plain paper) less than 256 g / m ² fed out from a paper feed tray (not shown) as a first sheet storage unit. It has a function / configuration as a first sheet conveying means having nipping and conveying means 8A. The first paper transport device 5C is substantially the same as the paper transport device 5A, except that the merge transport route is not formed, as compared to the paper transport device 5A shown in FIGS.
The second sheet conveying device 5B includes at least a belt conveying unit in a direction different from the conveying direction of 256 g / m ² or more sheets (for example, thick paper) fed out from a sheet feeding tray (not shown) as a second sheet storage unit. 8A has a function and configuration as a second sheet conveying means for nipping and conveying. The second paper transport device 5B includes a guide surface 70Ba formed to extend in the first transport path A direction instead of the transport guide member 70, as compared with the paper transport device 5A shown in FIGS. The point of using the transport guide member 70B, and the point of using the transport guide member 71B provided with a guide surface 71Ba extending in the direction of the first transport path A and facing the guide surface 70Ba instead of the transport guide member 71 are mainly used. Is different. A first transport path A is formed by the guide surface 70Ba and the guide surface 71Ba.

As shown in FIG. 27, from the center A1 of the nip portion between the feed roller 61 and the reverse roller 62 in the upper second sheet transport device 5B to the center B1 of the nip portion between the grip roller 81 and the pulley 83 via the transport belt 82. The sheet conveyance distance L1 of the first sheet conveyance device 5C in the lower stage is from the nip portion center C1 between the feed roller 61 and the reverse roller 62 to the center of the nip portion between the grip roller 81 and the pulley 83 via the conveyance belt 82. It is formed and set longer than the sheet conveyance distance L2. Specifically, the sheet conveyance distance L2 + L3 from the nip portion center C1 in the first sheet conveyance device 5C to the nip portion center B1 via the second conveyance path B and the conveyance belt 82 in the second sheet conveyance device 5B. Is set to be substantially equal to the sheet conveying distance L1 of the second sheet conveying apparatus 5B (L1≈L2 + L3).
A sheet feed tray (not shown) of the upper second sheet transport device 5B stores thick paper that is a sheet of 256 g / m ² or more, and a sheet feed tray (not shown) of the lower first sheet transport device 5C includes Paper of less than 256 g / m ^{2 is} stored. A registration unit including a registration roller pair (not shown) is disposed further downstream of the second conveyance path B from the nip center B1 via the conveyance belt 82 in the upper second sheet conveyance device 5B. .

Here, paper (plain paper) having the same metric basis weight as the lower paper feed tray (not shown) and less than 256 g / m ² is accommodated in the upper paper feed tray (not shown). Considering the case, the sheet conveying distance from the sheet feeding position at the center of the nip portion of the first conveying means 6 to the center of the nip portion of the upper second conveying means 7 is the same in both the upper and lower stages (L1≈ L2 + L3) and the influence of the conveyance load, the sheet conveyance time is almost constant between the upper stage and the lower stage, and the sheet interval between the preceding sheet and the following sheet is not greatly increased.
However, when sheets having different metric basis weights as described above are accommodated in the upper and lower sheet feed trays, the time when the sheet (thick sheet) is conveyed by the upper second sheet conveying device 5B is the lower first sheet. Since it becomes longer than the transport time of the paper (plain paper) transported by the transport device 5C, the paper interval between the preceding and succeeding papers when continuously feeding from the upper stage is widened. Also, if the leading paper is in the upper row and the following paper is in the lower row, the leading paper will take longer to transport, so if the paper interval is set short, the trailing edge of the leading paper will interfere with the leading edge of the trailing paper. There is a risk of doing. Therefore, the second embodiment has been created to solve this problem.

FIG. 28 shows a main control configuration around the sheet feeding device 3A of the present embodiment. The control device 43A is arranged mainly on the first paper conveyance device 5C side and the second paper conveyance device 5B side in relation to the paper interval between the preceding paper and the following paper. This is for controlling the paper feed start time related to the start / stop timing of the paper feed motor 23B.
The sheet feeding motor 23C and the sheet feeding motor 23B are sheet feeding motors composed of a common single stepping motor, and the first and second conveying means 6 of the first sheet conveying apparatus 5C and the second sheet conveying apparatus 5B are used. , 7 are all connected by driving force transmission means such as gears and belts, and an electromagnetic clutch is added thereto to transmit to the first sheet conveying apparatus 5C and the second sheet conveying apparatus 5B. Of course, it is possible to operate the paper feed motor by appropriately switching the driving force.

The control device 43A as a control means includes a control device 43A, an I / O (input / output) port (not shown), a ROM 45A, a RAM 46, a timer 48, etc., which are connected by a signal bus, almost as in the first embodiment. A microcomputer having the above-described configuration.
The CPU 44A, via the input port and sensor input circuit, etc., feed sensors 88C and 88B, vertical conveyance sensors 89C and 89B, thickness detection sensors 96C and 96B of the first and second paper conveyance devices 5C and 5B, It is electrically connected to the start switch and various keys (not shown) of the operation panel 95 as a unit. The paper feed sensors 88C and 88B, the vertical transport sensors 89C and 89B, and the thickness detection sensors 96C and 96B are substantially the same as the paper feed sensor 88, the vertical transport sensor 89, and the thickness detection sensor 96, respectively, in the first embodiment. The subscripts C and B are merely added to distinguish between the first and second paper transport devices 5C and 5B.

The CPU 44A is electrically connected to the paper feed motors 23C and 23B, each of which is a stepping motor, via the output port and a motor drive circuit (not shown), and a command signal for driving and controlling these paper feed motors 23C and 23B. Is transmitted to each motor drive circuit. In the present embodiment, driving / feeding of the paper feed motors 23C and 23B is performed under the condition that the rotational speeds of the paper feed motors 23C and 23B are constant, that is, the paper transport speeds of the first and second transport means 6 and 7 are constant. Stop timing is controlled.
In the ROM 45A, “related data for changing the start / stop timing of the paper feed motors 23C and 23B and the paper feed start time via the motor drive circuit” for the CPU 44A to perform the control function described above, “Data table relating to transport time for each thickness (paper type)”, “relation data on the number of pulses supplied to the paper feed motors 23C and 23B via the motor drive circuit”, “relation data relating to the above-described relational expressions”, etc. Stored and stored in advance.

Next, a description will be given of a control operation of main parts mainly executed under the control of the CPU 44A of the control device 43A. The paper feed start time from the start of feeding the paper in the upper feed tray (256 g / m ² or more: for example, thick paper) to the start of feeding the next paper is T2, and the lower feed tray (256 g / m ² ). m less than ^2: for example the paper on plain paper) from the feeding starts feeding start time to start feeding the next sheet as T1, and the T2 to set earlier than T1. Specifically, the transport time between the nip center A1 and B1 (paper transport distance L1) in the upper second paper transport device 5B is T4, and the nip center C1 and B1 (in the lower first paper transport device 5C) If the conveyance time between the sheet conveyance distances L2 + L3) is T3, the difference between the lower conveyance time and the upper conveyance time corresponds to a delay in the upper conveyance time, so T2 satisfying T2 = T1- (T4-T3) is satisfied. You just have to set it.

Next, a case where a sheet (256 g / m ² or more: thick paper, for example) in the upper sheet feed tray is a preceding sheet, and a subsequent sheet is a sheet (less than 256 g / m ^2, for example, plain sheet) in the lower sheet feed tray. I'll think about it. In this case, the upper leading paper has a paper feed start time earlier than that of the lower succeeding paper, but the time to reach the nip portion of the upper second transport means 7 from the start of feeding by the upper first transport means 6. It is longer than the bottom sheet. Accordingly, when the paper is started T1 after the paper feeding start time of the preceding paper as in the case of continuous feeding with the lower paper feeding tray, there is a possibility that it interferes with the trailing edge of the upper preceding paper. Therefore, when feeding the lower sheet continuously after feeding the upper sheet, it is preferable to set the feeding start time T1 ′ taking into account the upper conveyance delay. Specifically, the transport time between the nip center A1 and B1 (paper transport distance L1) in the upper second paper transport device 5B is T4, and the nip center C1 and B1 (in the lower first paper transport device 5C) If the conveyance time between the sheet conveyance distances L2 + L3) is T3, the difference between the lower conveyance time and the upper conveyance time corresponds to the delay in the upper conveyance time. Therefore, the sheet feeding start time T1 ′ = T1 + with the difference added. It is only necessary to set T1 ′ that satisfies (T4-T3). By setting the paper feed start time in this way, the trailing edge of the preceding paper and the leading edge of the succeeding paper interfere with each other even if the lower paper is fed continuously after feeding the upper paper. Can be prevented. As described above, according to the second embodiment, it is possible to eliminate the difference in productivity between the first and second paper transport devices 5C and 5B (paper feeding unit).

In the above description, the paper in the upper paper feed tray is 256 g / m ² or more and the paper in the lower paper feed tray is less than 256 g / m ^2. However, the metric basis weight of the paper may be reversed. Further, the upper and lower stages may be paper of 256 g / m ² or more.
In addition, a sheet conveyance time of less than 256 g / m ^{2 and} a sheet conveyance time of 256 g / m ² or more may be stored in advance in the ROM 45A as a storage unit, and the sheet feeding start time may be set by comparing the two. In this case, temperature condition data may be stored in the ROM 45A (which may be linked to the transport time), and the paper feed start time may be set in consideration of the temperature outside the apparatus.
Further, in the above description, the sheet feeding tray which is the main body side cassette of the paper feeding device 3A arranged above and below has been described as an example. However, the present invention is not limited to this configuration, for example, the main body side cassette of the paper feeding device 3A. A sheet (256 g / m ² or more) accommodated in a certain sheet feed tray and a sheet (less than 256 g / m ² ) accommodated in a manual feed tray of a manual sheet feed unit attached to the side of the apparatus. May be arranged in the same manner.
In the above description, it has been assumed that the distances of a plurality of paper feeding units are equal. However, if the distances are not equal, the time distribution considering the distances ensures the same productivity and leads Needless to say, interference between the paper and the following paper can be prevented.

(Third embodiment)
With reference to FIGS. 29 and 30, a third embodiment of the automatic document feeder of the present invention will be described.
FIG. 29 shows a cross-sectional configuration of the automatic document feeder in this embodiment. In FIG. 1, reference numeral 201 denotes an automatic document feeder (hereinafter also referred to as “ADF”), which is attached to the upper part of the document reading device 4 so as to be openable and closable instead of the document pressing plate 58 shown in FIG. First, the overall configuration of the ADF 201 of the present embodiment will be described with reference to FIG.
The configuration of the ADF 201 is the same except for the contents described in paragraphs “0013” to “0021” of Japanese Patent No. 3449870, for example. Hereinafter, description will be given with reference numerals obtained by adding a numerical value 200 to the reference numerals of main components used in the publication.

  As shown in detail in FIG. 29, the document reading device 4 is provided with a slit glass 203 and a contact glass 57 on its upper surface, conveys the document 206 by the ADF 201, and is placed on the slit glass 203 arranged at the reading position. Or the original is placed on the contact glass 57, and the image of the original is read. Further, the single-side mode and the double-side mode can be selectively set according to an instruction from the operation panel 95 shown in FIG. 18 or the like for operating the document reading device 4, and the document reading device 4 is set according to the set mode. The operation is controlled.

  Next, the ADF 201 will be specifically described. Reference numeral 205 denotes a document placement table as document placement means for placing and setting the document 206. In this example, the document 206 as a document sheet with the image surface facing upward is set in page order. Reference numeral 207 denotes a calling roller, which sends the document 206 to a separation unit downstream of the document transport path formed in the document sheet transport direction. Normally, the call roller 207 is in a stand-by position with a predetermined interval from the document mounting table 205. When the document placing sensor 208 detects that the document 206 is on the document placing table 205 and when an instruction to start feeding the document is given, the document 206 is lowered from the standby position and comes into contact with the upper surface of the document 206. Controlled and configured to move.

Reference numeral 209 denotes a feeding roller that rotates in the clockwise direction to feed the original 206 on the original table 205. Reference numeral 210 denotes a blocking roller, which is sequentially stopped from the uppermost original 206 by the frictional action among the originals 206 called by the calling roller 207 with the feeding roller 209 by rotating in the clockwise direction. Separate one by one. The feeding roller 209 and the blocking roller 210 constitute a separation unit that separates and feeds the original 206 into one sheet.
The calling roller 207 and the feeding roller 209 are connected to a document conveying motor 290 including a stepping motor as a driving unit via a driving force transmitting unit such as a timing belt and a timing pulley or a gear train (not shown). The calling roller 207 and the feeding roller 209 are first conveying means 260 (hereinafter also referred to as “first conveying means 260”) that feeds the original 206 to a separation unit downstream of the original conveying path formed in the original sheet conveying direction. ).

The first conveyance path RA1 is formed between the pair of guide members 211 and 211a, and is a path for moving the document 206 separated and conveyed by the feeding roller 209 of the separation unit onto the slit glass 203. The first transport path RA1 is provided in an arch shape between the separation unit and the slit glass 203 serving as a document reading unit, and the document 206 sent out by the feeding roller 209 is reversed to the slit glass 203. Lead.
The document discharge path RB is formed between the pair of guide members 212 and 212a, and moves the document 206 transported from the first transport path RA1 through the slit glass 203 to the document discharge port 213. Is the passage. Reference numeral 214 denotes a document discharge table on which the document 206 discharged from the document discharge port 213 is stacked, and is provided below the document placement table 205 and above the contact glass 57. A pressing means 215 made of an elastic member such as sponge or rubber is provided on the surface facing the contact glass 57 below the document discharge table 214. The pressing means 215 is placed at a predetermined reading position on the contact glass 57. The set original is pressed to prevent the original from floating from the contact glass 57.

The switchback conveyance path RC is formed between the pair of guide members 216 and 216a provided below the document placing table 205 and above the document discharge table 214, and the switching claw 217. This is a path for switching back the document 206 conveyed from the document discharge port 213 of the document discharge path RB and guiding it again to the first transfer path RA1. It is provided above the table 214.
The switching claw 217 is provided above the document discharge table 214 and switches the document 206 discharged from the document discharge port 213 at the end of the document discharge path RB by switching to the broken line position. Then, when the document 206 is introduced into the switchback conveyance path RC and then switched to the solid line position, the document 206 is switched back on the switchback conveyance path RC. Is guided from the rear end to the second transport path RA2. The switching claw 217 constitutes first switching means.

  The second transport path RA2 is formed between the pair of guide members 218 and 218a, merges with the first transport path RA1, and the document 206 switched back by the switchback transport path RC is the first. This is a path for moving to the transport path RA1. Reference numerals 219, 219a, 220, 220a, 221, 221a, 222, 222a are feed roller pairs. The pair of feed rollers 219 and 219 a and the pair of feed rollers 220 and 220 a transport the document 206 sent from the feed roller 209 in the first transport path RA 1 to the slit glass 203. The pair of feed rollers 221 and 221a conveys the document 206 that has passed over the slit glass 203 in the document discharge path RB to the document discharge port 213, and the pair of feed rollers 222 and 222a includes the second transport path. In RA2, the original 206 is transported to the first transport path RA1.

Reference numerals 223, 224, and 225 denote sheet feed rollers, which are provided in the vicinity of the document discharge port 213. Transport to the back transport path RC. Further, the document 206 switched back by the switchback conveyance path RC between the sheet feed rollers 224 and 225 is conveyed from the switchback conveyance path RC to the second conveyance path RA2.
Further, 226 and 226a are forward and reverse feed roller pairs (switchback members), and the feed roller pairs 226 and 226a are provided on the switchback transport path RC and transported into the switchback transport path RC. The incoming document 206 is introduced into the switchback transport path RC, and then reversely rotated to switch back the document 206 from the document discharge path RB and transport it to the second transport path RA2.

  227 is arranged at the entrance of the first conveying path RA1 between the feeding roller 209 and blocking roller 210 of the separating portion and the feeding roller pair 219, 219a, in the vicinity of the downstream side in the document conveying direction from the so-called feeding roller 209. The first document sensor 228 made up of the reflection type photosensor is an exit portion of the first transport path RA1 between the feed roller pair 220, 220a and the slit glass 203, that is, near the upstream side in the document transport direction from the so-called slit glass 203. A second original sensor 229 comprising a reflection type photosensor disposed on the reflection photosensor 229 is disposed on an original discharge path RB between the pair of feed rollers 221, 221a and the sheet feed rollers 223, 224. , 230 are reflection type photosensors disposed between the sheet feed rollers 223, 224, 225 and the feed roller pairs 226, 226a. . Each sensor 227, 228, 229, 230 detects the leading edge or trailing edge of the document 206 passing through the position.

It is arranged between the feed roller pair 219, 219a and the feed roller pair 220, 220a, that is, downstream of the first transport means 260 in the document sheet transport direction, and forms a curvature portion having a relatively small curvature radius. On the first transport path RA1, the second transport unit transports the document 206 transported by the first transport unit 260 in a document sheet transport direction different from the document sheet transport direction of the first transport unit 260. 270 (hereinafter also referred to as “second conveying means 270”) is disposed. Then, in the outer direction of the first transport path RA1 as a document sheet transport path formed between the first transport means 260 and the second transport means 270, a pinching portion (nip portion) of the second transport means 270 is provided. A belt conveying means 8A is arranged as a movement guiding means for guiding and conveying the original 206 toward it.
As described above, the grip roller 81 is driven by a mechanism similar to the drive mechanism shown in FIGS. 10 and 11, that is, via drive force transmission means such as a gear train, timing belt, and timing pulley (not shown). The driving roller is connected to a document conveying motor 290 including a stepping motor as a driving roller.
The belt conveying means 8A has the same configuration as that shown in FIGS. 10 to 17 and the like, and is arranged such that the leading edge of the document 206 is in contact with the antinode portion (effective conveying surface) of the so-called belt conveying surface 82a. The same is true for the belt conveying surface 82a and the belt conveying surface 82a. Of course, the third embodiment is not limited to the belt conveying means 8A, and the belt conveying means 8 shown in FIGS.

  Regarding the basic operation of the ADF 201, when the single-side mode is set, the same operation as described in paragraphs “0022” to “0025” of Japanese Patent No. 3449870 is performed, and the double-side mode is set. In this case, since it is performed in the same manner as described in paragraphs “0025” to “0030” of the publication, the description is omitted to avoid duplication.

  The control device 243 as the control means shown in FIG. 30 mainly relates to the start / stop timing of the document conveying motor 290 in relation to the document interval between the preceding document corresponding to the preceding sheet and the succeeding document corresponding to the following sheet. This is for controlling the paper feed start time. In order to simplify the explanation, there is a main control device as main control means (not shown) for controlling the overall operation of the copying machine 1 except for the control of the ADF 201. The main control device and the control device 243 are mutually connected. A description will be given assuming that command signals, on / off signals, data signals, and the like are transmitted and received. The main control device and the control device 243 are provided, for example, on a control board (not shown) on the image forming apparatus main body 2 side shown in FIG. In addition, when ADF201 becomes a movement unit as a goods form, you may make it provide the control apparatus 243 in the main body side of ADF201.

A control device 243 serving as a control means includes a CPU (central processing unit) 244, an I / O (input / output) port (not shown), a ROM (read only storage device) 245, a RAM (read / write storage device) 246 and a timer 248. And a microcomputer having a configuration in which they are connected by a signal bus.
The CPU 244 receives the first switch 227, the second document sensor 228, the thickness detection sensor 296, the start switch and various keys (not shown) of the operation panel 95 as an operation unit via the input port and the sensor input circuit. Are electrically connected to each other.

The first document sensor 227 and the second document sensor 228 detect by using the arrival time from when the document from the document placing table 205 as the document placing unit is fed until it reaches the second transport unit 270 instead. It has a function as arrival time detection means. This arrival time is the time from when the leading edge of the document is detected to be turned on by the first document sensor 227 to when it is detected to be turned on by the second document sensor 228. This is recognized by the CPU 244 through being timed by.
The thickness detection sensor 296 has a function as document sheet type detection means for detecting a document type (document sheet type) including the thickness of the document. In this embodiment, the document type is detected by detecting the thickness of the document. Is detected. As a specific example of the thickness detection sensor 296, similarly to the thickness detection sensor 96, for example, a known document thickness is detected by detecting the amount of light transmitted through the original when a laser beam is projected onto the original. A sensor is used.

  In addition to the various keys described in the first embodiment, the operation panel 95 sets that a document made of relatively stiff paper or the like is placed on the document placing table 205 and feeds the document. High-rigidity original (high-rigidity original sheet) selection key (hereinafter also referred to as “thick paper original selection key”) that generates a signal for driving the conveyance, and relatively low rigidity such as plain paper and thin paper other than thick paper A low-rigidity original selection key (hereinafter also referred to as “plain paper original selection key”) (not shown) that sets that the original is placed on the original placement table 205 and generates a signal for feeding and conveying the original. A thin paper document selection key or the like is provided. The thick paper document selection key, the plain paper document selection key, and the thin paper document selection key have functions as document sheet type setting means for setting the document type including the thickness of the document placed / set on the document placing table 205. .

The CPU 244 is electrically connected to the document conveying motor 290 formed of a stepping motor via the output port and a motor driving circuit (not shown), and transmits a command signal for controlling driving of the motor 290 to the motor driving circuit. . In the present embodiment, the driving / stop timing of the document conveying motor 290 is controlled under the condition that the rotation speed of the document conveying motor 290 is constant, that is, the document conveying speeds of the first and second conveying means 260 and 270 are constant. The
The RAM 246 temporarily stores the calculation result of the CPU 244, the thick paper original selection key, the plain paper original selection key, the thin paper original selection key, the first original sensor 227, the second original sensor 228, the thickness detection of the operation panel 95. An output signal from the sensor 296 or the like is stored as needed, and these signals are input / output.
In the ROM 245, “relevant data for changing the start / stop timing of the document conveying motor 290 and the feeding start time via the motor driving circuit” for the CPU 244 to perform the above-described control function, “document thickness A data table relating to the conveyance time for each (original type), “relation data on the number of pulses supplied to the original conveyance motor 290 via the motor drive circuit”, “relation data relating to the above-described relational expression”, etc. are stored and stored in advance. Has been.

Next, the operation will be described. Hereinafter, in this embodiment, for ease of understanding of the present invention, for the sake of explanation, an original of less than 256 g / m ² that is not a relatively rigid original is referred to as a “plain paper original”, for example. A document of 256 g / m ² or more which is a document will be described as a “thick paper document”, for example.
Here, as is apparent from FIG. 5 of the first embodiment, a document of less than 256 g / m ² (in this embodiment, for example, “plain paper document”) and a relatively stiff sheet of 256 g / m ² or more. For a document (for example, “thick paper document” in this embodiment), the transport time from the first document sensor 227 to the second document sensor 228 varies. Then, even if it is possible to continuously transport a document of 256 g / m ² or more by the belt transport unit 8 of the first embodiment, the transport time from the first document sensor 227 to the second document sensor 228 is 256 g / Since it is larger than the case of conveying a document of less than m ^2, when feeding a succeeding document with a paper interval of the same time T1 as described above, it is more than when conveying a document having a document interval of less than 256 g / m ^2. As a result, the number of documents conveyed per unit time decreases, and the operation rate of the apparatus, that is, productivity decreases.

Therefore, in the present embodiment, when continuously feeding a thick paper document of 256 g / m ² or more, the time T2 related to the start of feeding so that the subsequent document does not come into contact with the preceding document is normally less than 256 g / m ^2. In the case of continuously feeding a paper document, it is set shorter than the time T1 related to the start of feeding so that the subsequent document does not contact the preceding document, and the data is stored in the ROM 245 in advance (T1> T2). .
The time T2 is the arrival time T3 from the first document sensor 227 is a transport time to the second document sensor 228 at the time of conveying the document of less than 256 g / ^{m 2,} to transport the 256 g / ^{m 2} or more thick document The difference from the arrival time T4, which is the conveyance time from the first document sensor 227 to the second document sensor 228, is subtracted from the T1. In other words, the present embodiment is characterized in that the document conveying motor 290 is driven and controlled by the control device 243 so as to satisfy T1> T2 and T2 = T1- (T4-T3).

Therefore, according to the present embodiment, the time from the start of feeding a document to the ejection of the document is slower than that of a plain paper document for a thick paper document, but the feeding start time of a subsequent document is set to By making it faster than in the case of the above, it is possible to control so that the document interval between the preceding document and the following document is substantially the same as that in the case of the plain paper document. As a result, it is possible to ensure and achieve the same productivity as a plain paper document even when continuously feeding thick paper documents having different document thicknesses due to different document types.
In the case where the document type setting means is provided, productivity can be maintained even when the thickness of each document in the document bundle to be read is different (mixed loading).
In the case where the thickness detection sensor 296 is provided, even when the thickness of each original in the original bundle to be read is different (mixed loading), the thickness of each original is detected, and the supply is based on the result. Productivity can be maintained by controlling the feeding start time.

  Not only in the third embodiment, for example, similarly to the second modification of the first embodiment, a temperature / humidity sensor (temperature / humidity detection means) as a temperature detection means for detecting at least the temperature inside the apparatus of the ADF 201 is newly provided. By adding, the feeding start time T2 in the ADF 201 may be determined and controlled. In such a configuration, even if the strength of the document is affected by changes in environmental conditions including temperature and humidity, the feeding start time can be changed for each environmental condition, that is, the document transport time can be changed. By doing so, it is possible to provide an automatic document feeder that maintains productivity and does not reduce productivity.

  As described above, in each of the paper transport devices 5 and 5A and the ADF 201, one of the opposed pairs of the second transport means 7 (the nipping and transport means) is a front end or a front end portion (front end, front end face, The nip portion with the grip roller 81 while maintaining the contact / contact state with the tip or the edge, and gradually increasing the contact area depending on the rigidity of the paper or document. It can be said that it is an example of a movement guide means for moving and guiding a sheet or document toward the (nip part). Therefore, the movement guide means is not limited to the belt conveying means 8 and 8A, 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. 31B) 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 may be changed from a substantially horizontal direction to a downward downward direction (substantially vertical downward), or a vertical downward or upward change to a substantially horizontal direction (for example, FIG. 31A). 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.

  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 multifunctional machine etc. which combined at least two. 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 for sheet types as a wide variety of document 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 to fourth 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 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. 7 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 conveying means in the paper conveying device of FIG. 6. FIG. 7 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. FIG. 7 is a cross-sectional view of a main part showing still another sheet transporting apparatus to which the present invention is applied and FIGS. It is a simple perspective view which shows the drive mechanism in the paper conveying apparatus of the 4th example to which this invention is applied. It is a schematic front view of the principal part of FIG. FIG. 10 is a perspective view of a main part when a belt conveyance unit and a conveyance guide member are viewed from a grip roller side in a paper conveyance device of a fourth example. It is sectional drawing of the principal part around the 1st and 2nd conveying means in the paper conveying apparatus of the 4th example. It is the perspective view which looked around the belt conveyance means in the paper conveyance apparatus of the 4th example from the grip roller side. FIG. 10 is a perspective view of the periphery of a belt conveying unit in a paper conveying apparatus of a fourth example viewed from the back side of a conveying guide member. It is sectional drawing of the principal part around the 2nd conveyance means in the paper conveying apparatus of the 4th example. (A) is a schematic perspective view showing a specific opening / closing configuration on the sheet feeding apparatus main body side in the fourth example, and (b) is an opening / closing guide opened when removing jammed paper (jam paper). It is a simplified sectional view of the important section showing the state. It is a block diagram which shows the control structure in the paper conveying apparatus of the 1st reference example . It is a flowchart which shows the operation | movement flow of the principal part of the paper conveying apparatus of a 1st reference example . FIG. 3 is a block diagram illustrating a control configuration in the sheet conveying apparatus of the first embodiment . 4 is a flowchart illustrating an operation flow of a main part of the sheet conveying apparatus according to the first embodiment . FIG. 10 is a block diagram illustrating a control configuration in a sheet conveying apparatus according to a first modification . It is a graph for demonstrating the comparison test result regarding the conveyance time according to environment in the modification 1. FIG. 10 is a flowchart illustrating an operation flow of a main part of a sheet conveying device according to a first modification . FIG. 10 is a block diagram illustrating a control configuration in a sheet transport apparatus according to a second modification . 10 is a flowchart illustrating an operation flow of a main part of a sheet transport device according to a second modification . FIG. 6 is an enlarged cross-sectional view of a main part illustrating an upper and lower sheet transport device according to a second embodiment. FIG. 10 is a block diagram illustrating a control configuration in a sheet transport apparatus according to a second embodiment. It is sectional drawing of the principal part of the automatic document feeder of a 2nd reference example . It is a block diagram which shows the control structure in the automatic document feeder of the 2nd reference example . (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 main body 3, 3A Paper feeding device 4 Document reading device 5, 5A Paper conveying device (sheet conveying device)
5B Second paper conveying device (second sheet conveying means)
5C 1st sheet conveying device (first sheet conveying means)
5AB Additional unit (sheet transport unit)
6 First conveying means (first conveying means)
7 Second transport means (second transport means)
8,8A 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)
43, 43A Control device (control means)
44, 44A CPU (control structure of control means)
45, 45A ROM (control structure of control means, storage means)
48 timer (time measuring 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, 83b Pulley shaft (downstream shaft of the belt holding and 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, 84b Pulley shaft 95 Operation panel (operation unit)
96 Thickness detection sensor (sheet type detection means, sheet thickness detection means)
97 Temperature / humidity sensor (temperature detection means, temperature / humidity detection means)
98 Additional unit detection sensor (unit detection means)
201 ADF (automatic document feeder)
205 Document placement table (document placement means)
206 Original (Original Sheet)
243 Control device (control means)
244 CPU (control structure of control means)
245 (control structure of control means, storage means)
260 First transport unit 270 Second transport unit 296 Thickness detection sensor (original sheet type detection unit, sheet thickness detection unit)
A First transport path (sheet transport 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)
T1 paper feed start time (the time from the start of feeding a sheet to the start of feeding the next sheet when the sheet is not relatively rigid)
T2 paper feed start time (time from the start of feeding a sheet to the start of feeding the next sheet when the sheet is relatively rigid)
T3 arrival time (arrival time from when the sheet is fed to the second conveying means when the sheet is not relatively rigid)
T4 arrival time (arrival time from when the sheet is fed to the second conveying means when the sheet is relatively rigid)
Y Paper width direction (sheet width direction)
θ Entry angle

Claims (9)

First conveying means for feeding the sheet in the sheet conveying direction from the sheet accommodating means for accommodating the sheet ;
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 movement guide unit that is arranged in an outer direction of a sheet conveyance path formed between the first conveyance unit and the second conveyance unit, and moves and guides the sheet toward the second conveyance unit;
The sheet accommodating means, the first conveying means, the movement guide means, and the second conveying means constitute a sheet conveying unit that is detachable from the apparatus body,
Unit detecting means for detecting that the sheet conveying unit is mounted on the apparatus main body;
Second control means for changing the time until the start of feeding based on an output signal related to the mounting of the sheet conveying unit from the unit detecting means,
From the start of feeding a sheet to the start of feeding the next sheet when the sheet fed from the sheet containing means constituting the sheet containing unit and the sheet conveying unit is not a relatively rigid sheet Is set to T1,
When the sheet fed from the sheet accommodating means and the sheet accommodating means constituting the sheet conveying unit is a relatively high rigidity sheet, the feeding of the next sheet is started after the feeding of the sheet is started. When the time until is T2,
The sheet conveying apparatus according to claim 2, wherein T2 is set earlier than T1. When the sheet fed from the sheet storage means is not a relatively high rigidity sheet, the arrival time from the feeding of the sheet to the second transport means is T3,
When the sheet fed from the sheet storage means is a relatively high rigidity sheet, and the arrival time from the sheet feeding to the second transport means is T4,
T2 = T1- (T4-T3)
The sheet conveying apparatus according to claim 1, wherein: 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;
The sheet conveying apparatus according to claim 1, wherein the movement guide unit is disposed in a contour direction of the merging conveyance path. The sheet conveying apparatus according to claim 1, wherein the sheet having a relatively high rigidity has a metric basis weight of 256 g / m ² or more. Temperature detecting means for detecting the temperature inside the apparatus;
First control means for changing the T2 based on an output signal from the temperature detection means;
5. The sheet conveying apparatus according to claim 1, wherein the sheet conveying apparatus includes:   6. The sheet conveying apparatus according to claim 1, further comprising a sheet type detecting unit that detects a sheet type including a thickness of a sheet stored in the sheet storing unit.   The sheet conveying apparatus according to claim 1, further comprising a sheet type setting unit that sets a sheet type including a thickness of a sheet stored in the sheet storing unit. First sheet conveying means for holding and conveying at least a belt conveying means in a direction different from the conveying direction of a sheet less than 256 g / m ² fed from the first sheet accommodating means ;
Second sheet conveying means for holding and conveying at least a belt conveying means in a direction different from the conveying direction of 256 g / m ² or more sheets fed out from the second sheet accommodating means ,
The time from the start of feeding the sheet in the first sheet storage means by the first sheet conveying means to the start of feeding the next sheet is T1,
When the time from the start of feeding the sheet in the second sheet storage means by the second sheet conveying means to the start of feeding the next sheet is T2,
The sheet conveying apparatus according to claim 2, wherein T2 is set earlier than T1 . An image forming apparatus comprising the sheet conveying device according to claim 1 .

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