JP4621176B2 - Sheet conveying apparatus, image reading apparatus, and image forming apparatus - Google Patents

Description

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

  Conventionally, image forming apparatuses such as copiers, facsimiles, printers, printers, ink jet recording apparatuses, etc., including PPC (plain paper copier: plain paper copiers), etc., are designed to reduce the size of the entire apparatus. For transporting and supplying an image forming medium or a sheet-like recording medium (hereinafter referred to as “sheet”), which is a medium on which the image is formed, from the sheet storage means or the sheet stacking means for stacking sheets to the image forming means 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 a model of the image forming apparatus, 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 appropriately selects it. A sheet can be fed from the selected sheet storage unit or a 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, but the conveyance direction itself is greatly changed. 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 device 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 paper type in each stage on the lower side of the image forming unit main body. A sheet feeding tray is arranged, and a sheet is pulled out in the substantially horizontal direction of the selected sheet feeding tray between the sheet feeding tray and the image forming unit main body, 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 curvature radius of the curvature portion of the conveyance 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, and jamming and poor conveyance occur, preventing 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.

In Japanese Patent Application Laid-Open No. 2004-338923, a sheet feeding device that conveys a sheet fed from a first conveying unit to a second conveying unit that is positioned downstream in the conveying direction and substantially vertically above. A pair of linear guide members are provided between the first conveyance unit and the second conveyance unit, and a sheet feeding device that conveys a sheet by the guide of the linear guide member has been proposed. According to this paper feeding device, since the guide member is not a curved shape but a straight linear guide member, the conveyance load can be suppressed to a low level, that is, a rapid increase in the load can be suppressed, such as paper jam, skew feeding, etc. It is said that poor conveyance can be prevented.
In other words, according to the sheet feeding device, the deformed portion on the conveyed sheet is not concentrated on one curve by the curved guide member, but near the front and rear ends of the linear guide member in the conveyance direction. In addition, the linear guide member is installed in an oblique posture with a substantially intermediate angle so that the degree of bending at these two locations is approximately equal and the same. The rapid increase in load can be suppressed. That is, since the sheet changes its traveling direction, the curved portion is divided into two portions, a portion that is transferred from the upstream roller pair to the linear guide member and a portion that is transferred 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 force caused by bending at each portion can be kept low, so that it is possible to avoid a sharp increase in the transport load.

It has the 1st, 2nd conveyance means comprised like the said Unexamined-Japanese-Patent No. 2004-338923 (patent document 1), and it is 2nd between a 1st conveyance means and a 2nd conveyance means. 2. Description of the Related Art There is known a paper feeding device provided with a reversing guide member having an inclined surface that reaches a conveying unit, and the reversing guide member is configured to move toward a second conveying unit (for example, Patent Document 2). reference).
According to this paper feeding device, when the rear end of the sheet contacts the reversing guide member, the reversing guide member is displaced in a direction substantially the same as the direction in which the rear end of the sheet 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 are joined to one common conveyance path. And at least the conveyance path provided in the sheet accommodation means that accommodates the highly rigid sheet has a radius of curvature of the first curvature portion 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 another curvature portion when the conveyance paths of the two are merged (see, for example, Patent Document 3).
According to this sheet feeding device, a highly rigid sheet is curved to the same extent as a normal sheet when it passes through the first curvature portion having a large radius of curvature while traveling on the conveyance path. In contrast, since the sheet is kept curved sufficiently slowly as compared with the normal sheet, the resistance during 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 in 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 always in contact with the roller at the above-mentioned direction changing portion, and this roller is driven to rotate as the sheet is conveyed in the conveying direction. Compared to the conventional guide plate, the conveyance resistance can be reduced, that is, the frictional resistance generated between the fixed guide member and the moving sheet is eliminated, and the guide for changing the conveyance direction at the direction changing portion. I can do it.

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

However, in the sheet conveying device 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 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 paper (sheet) such as thick paper or an envelope is transported, the above-mentioned transport failure, jam, and the trailing sound of the paper 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.

  Further, as described in Patent Document 3, even in a configuration in which a dedicated conveyance path with a predetermined large radius of curvature is provided, the sheet traveling on the dedicated conveyance path is gently curved, and the sheet receives from the conveyance path. Even if the resistance is reduced, a transfer 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.

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

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

  In the present invention, the above-mentioned invention of the prior application can be used at a stable linear velocity even with a relatively high-stiffness (stiff) sheet, such as cardboard, while retaining advantages and effects such as space saving and low cost. Provided is a sheet conveying apparatus capable of conveying without problems on the downstream side of the sheet conveying path in the second conveying means, an image reading apparatus including the sheet conveying apparatus, a sheet conveying apparatus, and / or an image forming apparatus including the image reading apparatus. The main purpose is to do.

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

In order to solve the above-described problems and achieve the above-mentioned object, the invention according to each claim employs the following characteristic means / invention-specific matters (hereinafter referred to as “configuration”).
Invention of claim 1, wherein a first conveying means for conveying the sheet, is disposed on the downstream side in the sheet conveying direction of the first conveying means, the sheet first conveyed by the first conveying means A second conveying unit that conveys in a sheet conveying direction different from the sheet conveying direction of the conveying unit, and at least the second conveying unit of the first conveying unit and the second conveying unit sandwiches the sheet. One of the opposed pairs of the holding and conveying means in the second conveying means is a rotating and conveying driving means capable of transmitting a driving force by rotating, and the opposing conveying means. The other of the pair is disposed in the outer direction of the sheet conveyance path formed between the first conveyance unit and the second conveyance unit, and is driven by the rotation conveyance driving unit to move the sheet toward the clamping unit. Move guide to move and guide Der is, the rotary conveyor drive means comprises roller-shaped rotary conveyance driving member, said moving guide means comprises a belt conveying unit provided with a belt rotated together in contact the rotating conveying driving member directly, the The belt conveying means includes the belt made of an elastic member and at least a pair of belt holding and rotating members that hold the belt so that the belt can run, and the pair of belt holding and rotating members opens and closes with respect to the sheet conveying apparatus main body. The rotation conveying drive member is supported by the sheet conveying apparatus main body, and the opening / closing guide supports the belt holding rotating member via the belt and the rotation conveying driving member. A sheet conveying apparatus comprising urging means for urging in a direction in which the sheet is pressed against the sheet.

According to a second aspect of the invention, the sheet conveying apparatus according to claim 1 Symbol placement, the belt conveying means, the pre-Symbol each belt holding rotating member comprises a support member for rotatably supported, wherein each belt holding The rotating member is pivotally supported by the support member so as to keep the distance between the shafts constant, and the circumferential length of the belt when the belt is wound between the belt holding rotating members is the belt unit. The shaft of each belt holding and rotating member is disposed on the support member so as to be larger than the circumference of the support member.

According to a third aspect of the present invention, in the sheet conveying apparatus according to the second aspect , the belt is made of rubber having a rubber hardness of 30 to 60 degrees on a JIS A scale .

Invention of claim 4, the sheet conveying apparatus according to claim 3, wherein the belt, while maintaining the contact with the leading end of the sheet be those sheets moving-guiding, in contact with the leading end of the sheet The belt conveying surface is subjected to drawing.

Invention of claim 5, wherein, in the sheet conveying apparatus according to claim 3, wherein the belt, while maintaining the contact with the leading end of the sheet be those sheets moving-guiding, in contact with the leading end of the sheet The shape of the conveying surface of the belt is unevenly formed along a direction substantially parallel to the sheet conveying direction.

Invention according to claim 6, in the sheet conveying apparatus according to claim 3, wherein the belt, while maintaining the contact with the leading end of the sheet be those sheets moving-guiding, in contact with the leading end of the sheet The shape of the conveying surface of the belt is unevenly formed along a direction substantially orthogonal to the sheet conveying direction.

Invention of claim 7, wherein, in the sheet conveying apparatus according to claim 3, wherein the belt, while maintaining the contact with the leading end of the sheet be those sheets moving-guiding, in contact with the leading end of the sheet The shape of the conveying surface of the belt is formed to be uneven along a direction substantially skewed with respect to the sheet conveying direction.

Invention of claim 8, wherein, in the sheet conveying apparatus according to claim 3, wherein the belt, while maintaining the contact with the leading end of the sheet be those sheets moving-guiding, in contact with the leading end of the sheet The shape of the belt conveyance surface is formed in a substantially zigzag pattern with respect to the sheet conveyance direction.

The invention according to claim 9 is the sheet conveying apparatus according to any one of claims 1 to 8 , wherein the sheet is a strong sheet having a metric basis weight of 256 to 300 g / m ^2. To do.

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

According to an eleventh aspect of the present invention, there is provided an image forming apparatus including the sheet conveying device according to any one of the first to ninth aspects and / or the image reading device according to the tenth aspect.

According to a twelfth aspect of the present invention, in the image forming apparatus according to the eleventh aspect , the image forming apparatus is one of a copier, a facsimile, a printer, a printer, and an ink jet recording apparatus, or at least two of them. It is a combined multifunction device.

According to the present invention, a novel sheet conveying apparatus, an image reading apparatus including the sheet conveying apparatus, a sheet conveying apparatus and / or an image forming apparatus including the image reading apparatus are realized and provided by solving the above problems. Can do. The following are specific effects for each of the claimed inventions.
According to the invention of claim 1 and 9, wherein the above-described configuration, while a space-saving, simple and in a configuration requires only low cost, for example, be a strong sheet chewy such as thick paper, stable linear speed in the second conveying Jam can be easily handled by supporting the pair of belt holding and rotating members on an openable / closable guide that can be opened and closed with respect to the main body of the sheet conveying apparatus. Further, the belt holding rotating member and the belt supported by the opening / closing guide are brought into direct contact with the rotation conveying driving member so that the driving mechanism of the nipping / conveying means moves from the sheet conveying apparatus main body side to the opening / closing guide side. There is no straddle, the configuration is simplified, and biasing means for biasing the belt holding rotary member via the belt in a direction in which it is pressed against the rotary conveyance drive member is provided. By there, the sheet passing through the pinching portion can be reliably conveyed grip.

According to the invention of claim 2 and 9, wherein, by the upper Ki構 formed, for example, without providing a complicated mechanism such as a tightener mechanism, mechanism is simple, to achieve sheet conveying apparatus which requires space saving, low cost provides can do.

According to the third and ninth aspects of the present invention, the belt is made of rubber having a rubber hardness of 30 to 60 degrees on the JIS A scale, so that the tension when the belt is extended by its elasticity can be kept low. It is possible to suppress the belt rotation load and improve the followability of the belt to the rotation conveyance drive member. Further , by reducing the rubber hardness of the belt as described above , the leading edge of the sheet comes into contact with the belt. When the rear end of the sheet bounces to the belt side, or when the rear end of the sheet hits the belt, it is possible to reduce the splash sound.

According to the fourth to ninth aspects of the present invention, the belt conveying surface that comes into contact with the leading edge of the sheet is drawn, or the shape of the belt conveying surface is along a direction substantially orthogonal to the sheet conveying direction. By forming it in irregularities, forming it in irregularities along a direction that is substantially skewed with respect to the sheet conveying direction, or forming it in an approximately zigzag irregularity in the sheet conveying direction, an apparent belt By lowering the rubber hardness of the belt, the tension when the belt is extended and used can be further reduced, and the belt's rotational load can be suppressed and the followability of the belt to the rotation conveyance drive member can be further improved. that Do not.

According to the tenth aspect of the present invention, the image reading apparatus having the sheet conveying apparatus according to any one of the first to ninth aspects includes an automatic document feeder (ADF) that automatically feeds a document sheet. By using the image reading apparatus, it is possible to improve transportability of a stiff (high rigidity) original sheet such as a thick paper original in an automatic original feeder or the like with a space-saving, low-cost and simple configuration.

According to the eleventh aspect of the present invention, as an image reading apparatus having the sheet conveying apparatus according to any one of the first to ninth aspects and / or the image reading apparatus according to the tenth aspect , an original sheet is automatically fed. By using an image reading apparatus equipped with an automatic document feeder (ADF), etc., it is possible to transport stiff (high rigidity) sheets such as thick paper in a sheet conveying apparatus with a space-saving, low-cost and simple configuration. It is possible to realize and provide an image forming apparatus that improves the transportability of a stiff (high rigidity) original sheet such as a thick paper original in an automatic original feeder or the like.

According to the invention of claim 12, wherein the image forming apparatus, a copying machine, a facsimile machine, a printer, a printing machine and any one of the ink jet recording apparatus or a multifunction peripheral combining at least two of them, according to claim 11 The effects of the described invention are exhibited.

  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.

  FIGS. 4 to 10 to be 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 on which the sheet conveying apparatus is mounted. explain in detail. First, an overall configuration of a copying machine 1 as an example of an image forming apparatus will be described with reference to FIG.

The copying machine 1 is a monochrome copying machine that reads an image from the surface of a document and forms a copy image on recording paper, transfer paper, paper, OHP film, etc. as various sheet-like recording media (hereinafter referred to as “sheets”). is there. The copying machine 1 includes an image forming apparatus main body 2 that performs a predetermined image forming process based on a read document image, and a sheet S as an example of a sheet placed on the apparatus main body 2. Are fed one by one, and a document reading device 4 mounted on the image forming apparatus main body 2 for reading a document image and sending the document image information to the image forming apparatus main body 2.
A paper discharge tray 9 is installed on the upper part of the image forming apparatus main body 2, and a paper transport path R 1 (sheet transport path) as a paper transport path (sheet transport path) for moving the paper S from the paper feed device 3 to the paper discharge tray 9. Hereinafter, it is also referred to as “carrying path R1”. 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. Further, 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 the 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 with the roller is driven to rotate, and a predetermined heating temperature is set at a place where both the rollers 31 and 32 are in contact with each other. Thus, a nip portion for fixing the toner image on the paper is formed.
In the figure, reference numeral 20 denotes a toner storage container including a toner bottle that stores new and new toner, and 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 apparatus 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 accommodated. 2 is mainly composed of a traveling body 54, an imaging lens 55, and a reading sensor 56 such as a CCD.
Further, in the document reading device 4, a document pressing plate 58 configured to be openable and closable between a closed position covering the contact glass 57 and an opened open position 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 thereof is supported on the upper surface of the reading apparatus main body 4A by a hinge (not shown) so as to be freely 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 in which the automatically or manually selected sheet S is stored 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 conveyance roller or the like on the conveyance 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. It hits 21 and stops.
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, a toner image is transferred onto the paper S by the transfer device 13.

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

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

As described above, the paper conveyance direction of the first conveyance rotation member pair including the feed roller 61 and the reverse roller 62 and the paper conveyance direction of the second conveyance rotation member pair including the grip roller 81 and the conveyance belt 82 are: Different from each other, that is, the sheet conveying direction of the first conveying rotating member pair is set to a substantially horizontal direction that is an obliquely upper right direction in FIGS. 2 and 3, whereas the sheet conveying direction of the second conveying rotating member pair is The direction is set substantially vertically upward. Thus, the first conveyance path A formed between the first conveyance means 6 and the second conveyance means 7 is a curved curvature having a small curvature radius that causes the paper conveyance direction to change rapidly in the first conveyance path A. Forming part.
Here, the respective paper transport directions of the first and second transport means 6 and 7 are strictly expressed as follows. That is, in FIG. 4, the sheet conveying direction of the first conveying means 6 is the rotation center of the feed roller 61, the rotation center of the reverse roller 62, and the center of the nipping part (nip part) of the feed roller 61 and the reverse roller 62. Are set in a substantially horizontal direction orthogonal to the center of the nip portion in the line segment connecting the three points.
Similarly, the sheet conveying direction of the second conveying means 7 includes three points: the rotation center of the grip roller 81, the rotation center of the pulley 83, and the center of the gripping portion (nip portion) of the grip roller 81 and the conveying belt 82. It is set in a substantially vertical upward direction perpendicular to the center of the nip portion in the connecting line segment.

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

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

Further, as shown in FIG. 4, the belt conveying unit 8 causes the leading edge of the sheet S conveyed by the first conveying unit 6 to enter the conveying surface 82 a of the conveying belt 82 with an acute entry angle θ. It is also important to place them in By arranging 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 is surely brought into contact with the conveying surface 82 a of the conveying belt 82. The state of abutting on is maintained, and the effects described below can be obtained.
In the case where the leading edge of the sheet S is arranged so as to enter the conveying surface 82a of the conveying belt 82 with a substantially perpendicular or perpendicular entry angle θ, the leading edge of the sheet S enters the conveying surface 82a of the conveying belt 82. This is not preferable because the contact state becomes unstable, for example, it is bent in a direction opposite to the traveling direction of the conveyor belt 82 or repulsion is caused (the same applies hereinafter).

The paper feed trays 51 of each stage in the paper feed device 3 are formed in a substantially flat box shape having an upper opening, ensuring a planar shape capable of storing the maximum size paper S that can be handled by the copying machine 1. A bottom plate 50 as a sheet stacking unit is provided on the bottom surface. The bottom plate 50 is attached and fixed to a horizontal shaft 50A supported at the base end portion on the left side of FIG. The free end portion is configured to be swingable in the paper 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.

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 (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 rotated 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. A rubber having a high coefficient of friction with respect to the paper S is provided on the outer peripheral portion including the outer peripheral surface of the feed roller 61 so that when the paper S comes into contact with the paper S, it can be easily fed in the paper transport direction. Such a soft high friction material is used. Further, 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 core metal (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. As a result, 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 from the feed roller 61 to the paper S is reduced by the reverse transport force from the reverse roller 62.

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

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

The arrangement of the belt conveying means 8 is not limited to the arrangement state described above, and may be as follows. That is, in FIG. 3, reference numeral 79 shown in parentheses denotes an open / close guide configured to be openable and closable with respect to the housing 80 as a part of the main body of the sheet conveying device 5. The opening / closing guide 79 is provided with a hinge fulcrum shaft (not shown) below the housing 80 so that the user can easily handle jams, jams, and the like in the first conveyance path A and a vertical conveyance path extending substantially vertically upward. ) And the grip belt 81, the conveyor belt 82 can be freely opened and closed.
When such an opening / closing guide 79 is provided, the pulley 83 and the pulley 84 are rotatably supported on the opening / closing guide 79 side together with the pulley shafts 83a and 84a.

Although the conveyance belt 82 is partially described above, it is an endless belt and is stretched between the pulleys 83 and 84. The distance between the shafts of the pulleys 83 and 84 is set in advance. The linear belt running surface (conveying surface 82a) 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. As described above, the outer peripheral surface of the conveyor belt 82 wound around the outer peripheral surface of the pulley 83 is in direct contact with the outer peripheral surface of the grip roller 81 with a predetermined pressure, and a clamping portion (nip portion) is formed at this contact portion. Has been.
The conveyor 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 to the paper 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 transport 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 driving source (not shown) such as an electric motor provided exclusively for rotational driving of the grip roller 81 is provided on a rotational driving shaft 81a of the grip roller 81 with a driving force transmission means (not shown) such as a gear or a belt. Are connected through. 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.

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

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

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

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

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

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

  Next, Example 1 according to the prior invention 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 conveying rotating 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.

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). The paper was fed from the same tray in the 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 transport 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.

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 in FIG. 5, when the metric basis weight is 256 g / m ² or more as the paper type, the conveyance time is long and the paper slip is large in the conventional method, whereas in the belt method of the present invention, the conveyance time is not so long. It was found that the slip of the paper was small without being long. Further, it was found that the conveyance force decreases when the pickup pressure is reduced, but in the case of the belt system of the present invention, even if the pickup pressure is reduced, the conveyance time is not significantly affected. Therefore, when the belt system of the present invention is adopted, the pickup pressure can be reduced, so that the power of the drive motor can be reduced. As a result, the apparatus can be reduced in size.

Next, Table 1 that summarizes the sheet passing state based on the test results of FIG. 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 cannot pass the paper, but the belt method according to the present invention shown in FIGS. All the papers passed. Thereby, the remarkable effect of the belt system according to the present invention was recognized.
According to the comparative observation of the sheet passing / conveying state, when the metric basis weight is 256 g / m ² or more in the conventional method, the sheet becomes stiff and difficult to bend along the curved sheet conveying path. Referring to FIGS. 1 to 3, 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 paper passing / conveying state using a paper whose surface portion was coated and a paper whose surface was not coated. However, significant differences other than the test results in Table 1 were not recognized.

From the observation results of the paper conveyance process in Example 1 described above, the following was found. That is, when the highly rigid paper S having a metric basis weight of 256 g / m ² or more is transported from the first transport unit 6 to the transport surface 82a of the transport belt 82 in the belt transport unit 8 via the first transport path A. Because of the high straightness transportability of the highly rigid paper S, the various guide members constituting the first transport path A are changed to simple shapes that reduce the transport load resistance or the various guide members are changed. It turns out that it is possible to make it completely unnecessary.
Therefore, in the case of a sheet conveying apparatus that conveys using only the relatively rigid sheet S, the essential components are the first conveying means 6, the second conveying means 7, the first and The second transport unit is disposed in the outer direction of the first transport path A (in this case, no guide member is formed) formed between the second transport units 6 and 7 and maintains a state in contact with the leading edge of the sheet S. Belt conveying means 8 (movement guiding means) for moving and guiding the paper S toward the paper 7.
From the above, the various guide members forming the first transport path A have relatively low rigidity, for example, when the paper S such as plain paper or PPC is transported, the straightness of the paper S with low rigidity is weak. It can be said that it is necessary to compensate for the straightness as compared with the paper S having relatively high rigidity such as thick paper, and to guide and guide it to the transport surface 82a of the transport belt 82. In other words, the first conveyance path is used to compensate for the decrease in straightness as the rigidity of the sheet S decreases and to make the leading edge of the sheet S abut against the antinode portion of the conveyance surface 82a of the conveyance belt 82. It can be said that it is necessary to set the shape of the guide surfaces of the various guide members forming A.
In other words, as the sheet S having higher rigidity (the sheet S having a larger metric basis weight ) is used, the various guides used when configuring the sheet conveyance path of the curvature portion having the relatively small curvature radius described above. It becomes possible to give a degree of freedom to the design of the shape and arrangement of the members.

  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. It is possible to provide a sheet conveying apparatus and an image forming apparatus excellent in the above. In other words, basically, the conveyor belt is wound around the existing roller that constitutes the second conveying means, and the belt conveying means 8 is newly provided and added, and a dedicated drive source for the belt conveying means 8 is also provided. The sheet conveying device and the image forming apparatus can be realized at a low cost because of the extremely simple configuration.

  In the conventional configuration, it is not possible to cope with a high-rigidity paper type and a conveyance failure occurs. On the other hand, the paper conveyance device 5 can cope with a high-rigidity paper type and has excellent paper type characteristics. It becomes a transfer device. 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 giving the conveyance driving force. 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 travel 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. Therefore, as the contact area increases, the resistance force between the two can be increased, and a larger transport driving force for advancing the sheet S in the transport direction can be supplied from the transport belt 82 to the sheet 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. That is, 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.
Accordingly, even if the rigidity of the sheet S is high, the sheet S can be surely directed toward the sandwiching portion of the downstream second conveying 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 holding 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, can expand its transport support capability, and obtain high paper transport performance.

(Modification of the first example)
FIG. 6 shows a modification of the first example to which the invention of the prior application is applied.
As shown in FIG. 6 (a), one of the opposed roller pairs of the first conveying means 6 arranged on the upstream side may be the belt conveying means 8, and as shown in FIG. Of the pair of rollers in contact with each other in the first conveying means 6 and the second conveying means 7, one of both sides may be the belt conveying means 8 and 8 ', and further, as shown in FIG. As a moving guide means (moving guide) that substitutes for either one of the roller pair of the first conveying means 6 arranged in the side or one of the roller pair of the second conveying means 7 arranged on the downstream side, these A separate and independent belt conveying means 8 may be provided between the two roller pairs.

In the belt conveying means 8 in the modified example shown in the lower side of FIGS. 6A and 6B, for example, the separation action of the reverse roller 62 (counterclockwise rotation for returning paper) is affected. The reverse roller 62 is divided into a skewered shape in the axial direction so that the reverse roller 62 is provided, and a roller bearing or the like (not shown) is provided on the outer peripheral side of the shaft between the divided reverse rollers 62 (the portion where the reverse roller 62 is not present). In addition, by providing a skewer roller pulley (not shown) having an outer diameter slightly smaller than the outer diameter of the reverse roller 62, the conveyance belt 82 is driven to rotate and rotate in the clockwise direction to convey the sheet. What is necessary is just to convey to the 2nd conveyance means 7 and belt conveyance means 8 'of the downstream of this. In the nip portion between the feed roller 61 and the reverse roller 62, the conveying belt 82 is provided one step lower than the outer peripheral surface of the reverse roller 62 so as not to form the nip portion. Thus, after the sheet is fed out while being separated into one sheet at the nip portion between the feed roller 61 and the reverse roller 62, the above-described operation of the conveyor belt 82 may be exhibited.
Therefore, any of the above-described modified examples can obtain at least the same effects as the first example described above.
(Second example)

  A second example to which the invention of the prior application is applied will be described with reference to FIGS. The same components and members as those of the sheet conveying device 5 shown in FIGS. 1 to 4 are denoted by the same reference numerals, and the description thereof is omitted or simplified. Although not particularly described, the configuration not described in this example, that is, the paper transport device and other configurations and their operations are the same as those of the paper transport device 5 of the first example shown in FIGS.

  The sheet conveying apparatus 5 shown in FIGS. 7 to 9 is a first conveying unit 5 formed between the first conveying means 6 and the second conveying means 7 as compared with the sheet conveying apparatus 5 shown in FIGS. In addition to the first conveyance path A serving as the sheet conveyance path, another independent second sheet conveyance path formed from the upstream of the second conveyance means 7 to the second conveyance means 7 and different from the first conveyance path A A point having the second conveyance path B, and a first conveyance path A and a second conveyance path B merge at the upstream of the second conveyance means 7 (hereinafter also referred to as “merging conveyance path”). The main difference is that the belt conveying means 8 of the second conveying rotating member pair is disposed so as to be dislocated in the outline direction of the merged conveying path of the first and second conveying paths A and B. The sheet conveying apparatus 5 shown in FIGS. 7 to 9 is the same as the sheet conveying apparatus 5 shown in FIGS. 1 to 3 except for the differences.

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

Next, the conveying operation of the sheet conveying device 5 shown in FIGS. 7 to 9 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 2, 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. 8, after the sheets S are separated one by one by the sheet feeding / separating mechanism, one sheet S is conveyed with a gentle bend so that the conveyance resistance can be reduced, and the leading end of the sheet S is conveyed. 82 abuts.
Since the conveyor belt 82 travels in a substantially vertical direction (substantially above) indicated by an arrow a in FIG. 8, the leading edge of the sheet S that is in contact with the conveyor belt 82 is As shown in FIG. 9, it is conveyed to the clamping part (nip part) between the grip roller 81 and the conveyor belt 82, and is clamped and conveyed to the downstream side in the substantially vertical direction by the pair of the grip roller 81 and the conveyor belt 82. . At this time, as described above, the sheet S is subjected to the conveyance driving force that is transmitted from the conveyance belt 82 in the conveyance direction, and is directed toward the nip portion between the grip roller 81 and the conveyance belt 82 by the conveyance belt 82. Therefore, even a highly rigid paper S can be stably conveyed without causing a conveyance failure.

  As described above, according to the paper transport device 5 shown in FIGS. 7 to 9, the paper transport device having the merging transport path is the same as the paper transport 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.

  The second example is not limited to the example in which the belt conveying unit 8 is configured using the existing second conveying roller pair 81 and 83 as illustrated in FIGS. 7 to 9, and is illustrated in FIG. 6C. Similarly to the modification of the first embodiment, the belt conveying means 8 that is independent from the second conveying roller pair 81 and 83 may be provided.

(Third example)
With reference to FIG. 10, a third example to which the invention of the prior application is applied will be described. 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. 10, when the trailing end Se of the curved sheet S during the conveyance is removed from the support by the guide member 71 or the like, the arrow b shown in FIG. A splash phenomenon occurs in which the trailing edge Se of the sheet S moves in the 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 it is removed from the member 71 or the like, it is supported only at the leading end side, and the trailing end Se of the sheet S instantaneously collides with the conveying surface 82a of the conveying belt 82 by the elastic restoring force of the curved sheet S. 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 conveyance surface 82 a side of the conveyance belt 82. Accordingly, a portion of the conveyance belt 82 on the conveyance surface 82a side has appropriate elasticity, and the impact caused by the trailing edge Se of the sheet S is absorbed by the elastic action of the conveyance belt 82, so Even when the highly rigid 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 conveyance surface 82a of the conveyance belt 82, it can be sufficiently elastically deformed so that the conveyance surface 82a of the conveyance belt 82 is displaced in the collision direction as shown by a two-dot chain line in the figure. Since the impact of the trailing edge Se can be absorbed, the magnitude of the sound generated by the collision can be reduced, and the generation of abnormal noise as the operation sound of the paper transport device can be suppressed and mitigated.

As described above, according to the paper transport device 5 of the third example, the rear end Se of the transported paper S contacts the belt 82 at a location different from the location where it contacts the transport surface 82a of the transport belt 82. Since the tension roller 85 is disposed as a contact member for supporting the sheet S, when the sheet S is conveyed in a predetermined curve, the rear end Se of the sheet S is When the carrier belt 82a collides with the conveyance surface 82a after being separated from either the nip portion or the guide member 71, the collision belt 82 is sufficiently elastically bent to absorb the impact. It is possible to suppress sudden sound (honeycomb) generated by the collision. That is, when the trailing edge Se of the sheet S is in contact with the conveying surface 82a of the conveying belt 82, the contact member does not hinder the deformation of the conveying belt 82 where the trailing end Se of the sheet S contacts, and the trailing edge of the sheet S is prevented. The conveyor belt 82 can be sufficiently bent in the contact direction of the end Se.
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 contacts the conveying surface 82a side of the conveying belt 82 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, Since a certain degree of elastic deformation of the conveying belt 82 can be expected, the leading edge of the paper S does not flounce from the conveying surface 82a, that is, does not repel, and is brought into contact with the software, and is shifted to the state in which it is in contact. Is possible. That is, with respect to the conveyance surface 82a of the conveyance belt 82 traveling so as to travel in the sheet conveyance direction, the leading edge of the sheet S conveyed by the first conveyance means 6 for the first time obliquely enters the conveyance angle 82 ( 8), the leading edge of the sheet S can be shifted to the advancing direction by following the conveying surface 82a without repelling the leading edge of the sheet S from the conveying surface 82a. .

  The third example is not limited to the one shown in FIG. 10. 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 facing manner as in the configuration shown in FIG. 10. 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 contrary, a tension roller for pressing and urging inward from the outside of the belt to ensure tension may be provided.
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 sheet 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 7 to 10 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 transport rotation composed of two transport rotation members arranged opposite to each other, the grip roller 81, the roller pulley 83, and the transport belt 82 stretched between the roller 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 driven in contact with the grip roller 81, the drive / driven side is not necessarily clarified The technical contents include that the conveyance belt 82 side may be driven.
On the other hand, in the first embodiment and the like of the present invention, 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 addition, as described above, the conveyance belt 82 of each of the sheet conveyance devices 5 illustrated in FIGS. 1 to 4 and 7 to 10 has a width of the conveyance belt 82 in the sheet width direction Y of at least the maximum size 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 first embodiment and the like are configured as follows.

(First embodiment)
With reference to FIG. 11 to FIG. 17, the sheet conveying device 5 </ b> A of the first embodiment will be described. FIGS. 11 and 12 simply show a drive mechanism 22 as a feeding drive means (feeding drive system) of the first conveying means 6 and the second conveying means 7 in the paper conveying apparatus 5A of the first embodiment. ing. FIGS. 13 to 17 show in detail the periphery of the belt conveying unit 8A of the second conveying unit 7 in the sheet conveying apparatus 5A of the first embodiment.
The sheet conveying apparatus 5A of the first embodiment shown in FIGS. 11 to 17 is a second conveying 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 instead of the belt conveying means 8 to clarify the driving / following relationship of the means 7, and 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 and the material of the conveyor belt 82 is specified. The sheet conveying apparatus 5A of the present embodiment is the same as the sheet conveying apparatus 5 shown in FIGS. 1 to 4 and FIGS. 7 to 10 except for the differences described above.

  That is, the second conveying means 7 of the sheet conveying apparatus 5A is provided with a rotary conveying driving means / rotary conveying driving member that can transmit a driving force when one of the opposed pairs of the nipping conveying means rotates. The other of the opposed pair is arranged 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 and directly contacts the grip roller 81. Then, the belt conveyance provided with the conveyance belt 82 that conveys (moves / guides) the paper S toward the nipping portion (nip portion) of the second conveyance means 7 while holding the state in contact with the leading edge of the paper S. It is characterized by comprising means 8A (movement guide means).

  Further, the sheet conveying apparatus 5A according to the first embodiment has a maximum sheet width that the width of the conveying belt 82 conveys as compared with the sheet conveying apparatus 5 illustrated in FIGS. 1 to 4 and 7 to 10. Instead of the above-described length, the lengths of the pulleys 83 and 84 and the grip roller 81 are continuously formed in the paper width direction Y so as to be longer than the width of the conveying belt 82. The sheet width direction Y of the conveyance belt 82 in the belt conveyance unit 8A is in contact with a part of the leading edge (including the leading edge, the leading edge surface, and the corner / edge of the leading edge) of the sheet S in the sheet width direction Y. It is characterized by being configured intermittently in the width 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. 11 and 16, three grip rollers 81 are arranged on the rotation drive shaft 81 a, and three conveyance belts correspond to and face the three grip rollers 81. 82 is arranged with a width substantially equal to each grip roller 81. This detailed configuration will be described later.
In FIG. 11, 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 unevenly. Of course, it is arranged at intervals.

As shown in FIGS. 11 and 12, 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, a grip roller drive gear 81A fixed to one end of the rotation drive shaft 81a of the grip roller 81, a feed roller gear 61A fixed to the other end of the shaft 61a near the feed roller 61, and this feed 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 the present embodiment, the paper transport device 5A is compact and space-saving, that is, the first transport path A is configured with a curvature portion having a relatively small radius of curvature as illustrated in the first embodiment. Therefore, the sheet feeding motor 23 is single and serves as the driving means for the first conveying means 6 and the second conveying means, contributing 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. 11, 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. 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.

Next, with reference to FIGS. 13 to 17, a detailed configuration mainly on the side of the belt conveying means 8 </ b> A arranged 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. 7 to 10, the belt conveying means 8A of the paper conveying device 5A specifies the material of the conveying belt 82 as follows. In that case, instead of the three pulleys 83 fixed on the pulley shaft 83a, three pulleys 83 are rotatably supported on the pulley shaft 83b, and fixed on the pulley shaft 83a. Instead of the three pulleys 83, the three pulleys 83 are rotatably supported on the pulley shaft 83b, the pulleys 83, 84 are formed of a resin such as polyacetal resin, The belt support member 86 is used as a support member that rotatably supports the shafts 83 and 84. Instead of the pulley shaft 84a that is long and continuous in the axial direction, a metal 3 having a short length in the axial direction is used. Pulley shaft 84b Feature points and below is used differs mainly.

  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. For example, ethylene / propylene rubber (EPDM) as an elastic member is used as the material of the conveyor belt 82, and a base material (usually, the belt is often used to attach rubber to a base material such as a cloth woven with fibers). It is made of rubber without any material. In addition to the above, for example, urethane rubber (U) or the like is used as the material of the conveyor belt 82.

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 spanned 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. 14, the back surface of the belt support member 86 is biased 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. 15, 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 this positioning portion 86b is transported. By contacting the guide member 72, the position of the conveyance belt 82 itself is positioned. 14 and 17, the positioning portion 86b and the conveyance guide member 72 are brought into contact with each other by the urging force of the spring 92, whereby the conveyance belt 82 is positioned at a predetermined position. The belt protruding amount h can be secured.

As shown in detail in FIG. 17, 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. 15 about the pulley shaft 83b. .
Referring to FIGS. 14 and 17, 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.

As described above, the conveying belt 82 of the belt conveying means 8A in the present embodiment has a pair of roller-like pulleys depending on the relationship of assembling the pulleys 83 and 84 to the belt support member 86 via the pulley shafts 83b and 84b. It is spanned between 83 and 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 and rotated as the grip roller 81 rotates. .
The rubber hardness of the conveyor belt 82 is such that when the conveyor belt 82 is stretched along the pulleys 83 and 84, if the rubber hardness is large, the straight portion between the pulleys 83 and 84 is due to the hardness of the conveyor belt 82 itself. Try to swell outward. If the expansion ratio is increased in order to prevent this, the tension of the conveyor belt 82 increases, and the rotational load of the conveyor belt 82 increases this time, making it difficult to follow the grip roller 81 and follow it.

  Therefore, the test was performed under the same test conditions as the tests shown in FIG. 5 and Table 1 as Example 2, and when the follower load of the conveyor belt 82 was at a level that would not cause a problem, it was made of ethylene / propylene rubber. The test results shown in Table 2 below were obtained as the relationship between the rubber hardness, the stretch ratio, and the thickness of the conveyor belt 82.

  From the test results of Table 2, it was found that when the rubber hardness is small, the influence on the rotation of the conveyor belt 82 is small even if the expansion ratio is large. Further, when the rubber hardness is high (80 degrees), the same effect can be obtained by reducing the thickness of the conveyance belt 82. However, when the thickness is reduced, the mechanical strength of the conveyance belt 82 is reduced. In consideration of wear over time, it is difficult to make the thickness too small or thin. For this reason, the rubber hardness of the conveyor belt 82 is a JIS A scale, and is used in a relatively low hardness region of 30 to 60 degrees without being affected by mechanical strength, wear over time, etc. It turns out that an effect is acquired.

  Therefore, according to the first embodiment, 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.

Second, the pulleys 83 and 84 (belt holding and rotating members) are pivotally supported by a belt support member 86 (support member) so as to keep the distance between the shafts constant. The pulley shafts 83b and 84b of the pulleys 83 and 84 are attached to the belt support member 86 so that the circumference of the conveyor belt 82 when the conveyor belt 82 made of an elastic member is wound is larger than the circumference of the conveyor belt 82 alone. With this arrangement, in this embodiment, as a means for applying a tension to the belt, a mechanism for applying a tension to a belt called a commonly used tie toner is not provided, and the conveying belt 82 is elastically provided between the two-shaft pulleys 83 and 84. Because it has a structure that stretches and tensions it, it is simpler than conventional structures such as Tightener, which saves space and costs. It can be.
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.

Third, the conveyor belt 82 is made of a rubber having a relatively low hardness, specifically, by using a rubber having a JIS A scale and a relatively low hardness of 30 to 60 degrees. The tension when the conveyor belt 82 is extended and used can be kept low without being affected by mechanical strength, wear over time, and the like. When the tension of the conveyor belt 82 is high, the conveyor belt 82 is rotated, so that the rotational load of the conveyor belt 82 increases, and the linear velocity same as that of the roller 81 follows the grip roller 81 driven thereby. It becomes difficult to rotate with.
In this embodiment, since the tension of the conveyor belt 82 can be suppressed without being affected by mechanical strength, wear with time, etc., it is possible to suppress the rotational load of the conveyor belt 82, thereby driving. It becomes possible to reliably rotate following the grip roller 81 as a roller. That is, it is possible to reduce the accompanying load of the conveying belt 82, which is a problem when the conveying belt 82 is rotated.
Further, by reducing the rubber hardness of the conveying belt 82, the sound when the leading edge of the sheet S comes into contact with the conveying surface 82a of the conveying belt 82, and the sheet S when the trailing edge of the sheet S bounces toward the conveying belt 82 side. It is also possible to reduce the squeaking noise that occurs when the rear end suddenly hits the conveying surface 82a of the conveying belt 82.

  Hereinafter, various modifications of the first embodiment will be described with reference to FIGS. 18 to 22 in order. In FIGS. 18 to 22, the belt support member 86 is simplified to simplify the drawings. It is noted that the illustration of the retaining ring and the like is omitted. The assembly, shape, etc. of the components of the belt conveying means excluding the conveying belt are the same as those of the belt conveying means 8A of the first embodiment.

(Modification 1)
FIG. 18 shows a first modification of the first embodiment. Modification 1 includes a conveyance belt 82 (hereinafter simply referred to as “conveyance belt 82 of the first embodiment”) in the belt conveyance means 8A of the sheet conveyance device 5A of the first embodiment shown in FIGS. In comparison, the only difference is that a conveying belt 82A that has been subjected to drawing (texturing) processing is used for the conveying surface 82a that contacts the leading edge of the paper S.
The conveyance belt 82A is in contact with the grip roller 81 and the paper S only in the convex portion of the diaphragm, so that the linear velocity of the conveyance belt 82A is determined by the thickness of the convex portion of the diaphragm. Since the thickness of the concavity of the diaphragm is small, the apparent rubber hardness of the conveyance belt 82A is smaller than that of the conveyance belt 82 having a uniform thickness over the entire surface.
The diaphragm shown in the figure has a relatively shallow unevenness along a direction substantially parallel to the horizontal line. For mass production, it is desirable to form the diaphragm with a mold, and mass production is not desired. If possible, it may be formed by grinding or the like.
The diaphragm is not limited to a convex shape along a direction parallel to the substantially horizontal line, and the directionality and pattern thereof may be arbitrary, and may be uneven.

Therefore, according to the first modification, it is possible to reduce the apparent rubber hardness of the conveyance belt 82A by using the conveyance belt 82A that has been subjected to drawing processing on the conveyance surface 82a that contacts the leading edge of the sheet S. The tension when the conveyor belt 82A is extended and used can be kept low.
When the tension of the conveyor belt is high, the conveyor belt is rotated, so that the rotational load of the conveyor belt increases, and the grip roller 81 driven thereby follows the same linear velocity as the roller 81. It becomes difficult to rotate.
In this modification, since the tension of the conveyor belt 82A can be suppressed, it is possible to suppress the rotational load of the conveyor belt 82A, and thus it is possible to rotate following the grip roller 81. That is, it is possible to reduce the accompanying load of the conveying belt 82A, which is a problem when the conveying belt 82A is rotated.
Further, by reducing the apparent rubber hardness of the conveyance belt 82A, the sound when the leading edge of the paper S comes into contact with the conveyance surface 82a of the conveyance belt 82A, and when the trailing edge of the paper S bounces toward the conveyance belt 82A. Further, it is also possible to reduce the splash sound that occurs when the trailing edge of the paper S suddenly hits the conveyance surface 82a of the conveyance belt 82A.

(Modification 2)
FIG. 19 shows a second modification of the first embodiment. In the second modification, the shape of the conveyance surface 82a that comes into contact with the leading edge of the paper S is formed to be uneven along a direction substantially parallel to the paper conveyance direction, as compared with the conveyance belt 82 of the first embodiment. The only difference is that the transport belt 82B is used.
The conveyance belt 82B is in contact with the grip roller 81 and the paper S only in the convex portion, and therefore the linear velocity of the conveyance belt 82B is determined by the thickness of the convex portion. Since the recess has a small thickness, the apparent rubber hardness of the conveyance belt 82A is smaller than that of the conveyance belt 82 having a uniform thickness over the entire surface.
The uneven shape of the conveyor belt 82B is desirably formed by a mold in terms of mass productivity, and may be formed by grinding if mass productivity is not desired (the same applies to the following modified examples).

  Therefore, according to the second modification, the shape of the conveyance surface 82a that contacts the leading edge of the sheet S is apparently formed by using the conveyance belt 82B that is formed unevenly along a direction substantially parallel to the sheet conveyance direction. It is possible to reduce the rubber hardness of the transport belt 82B, and it is possible to keep the tension when the transport belt 82B is extended and used low. In addition, the same advantages and effects as those of the first modification are also obtained.

(Modification 3)
FIG. 20 shows a third modification of the first embodiment. In the modified example 3, as compared with the conveyance belt 82 of the first embodiment, the shape of the conveyance surface 82a that comes into contact with the leading edge of the sheet S is formed to be uneven along the direction orthogonal to the sheet conveyance direction. The only difference is the use of.
The conveyance belt 82C is in contact with the grip roller 81 and the paper S only in the convex portion, and therefore the linear velocity of the conveyance belt 82C is determined by the thickness of the convex portion. Since the recess has a small thickness, the apparent rubber hardness of the conveyor belt 82C is smaller than that of the conveyor belt 82 having a uniform thickness over the entire surface.

  Therefore, according to the third modification, the apparent conveyance belt is formed by using the conveyance belt 82 </ b> C in which the shape of the conveyance surface 82 a in contact with the leading edge of the sheet S is formed unevenly along the direction orthogonal to the sheet conveyance direction. The rubber hardness of 82C can be lowered, and the tension when the conveyor belt 82C is extended and used can be kept low. In addition, the same advantages and effects as those of the first modification are also obtained.

(Modification 4)
FIG. 21 shows a fourth modification of the first embodiment. In the fourth modification, the shape of the conveyance surface 82a that contacts the leading edge of the paper S is formed to be uneven along the direction substantially oblique to the paper conveyance direction, as compared with the conveyance belt 82 of the first embodiment. In other words, the only difference is the use of the conveyor belt 82D formed in substantially knurled irregularities. In the figure, a substantially knurled portion indicated by a solid black line represents a convex conveying surface 82a.
The conveyance belt 82D is in contact with the grip roller 81 and the paper S only at the convex portion, and therefore the linear velocity of the conveyance belt 82D is determined by the thickness of the convex portion. Since the concave portion has a small thickness, the apparent rubber hardness of the conveyor belt 82D is smaller than that of the conveyor belt 82 having a uniform thickness over the entire surface.

  Therefore, according to the fourth modification, the appearance of the conveyance surface 82a that comes into contact with the leading edge of the sheet S is apparent by using the conveyance belt 82D that is unevenly formed along the direction substantially oblique to the sheet conveyance direction. The rubber hardness of the upper conveyor belt 82D can be reduced, and the tension when the conveyor belt 82D is extended and used can be kept low. In addition, the same advantages and effects as those of the first modification are also obtained.

(Modification 5)
FIG. 22 shows a fifth modification of the first embodiment. In the modified example 5, as compared with the conveyance belt 82 of the first embodiment, a conveyance belt 82E in which the shape of the conveyance surface 82a in contact with the leading edge of the sheet S is formed in a substantially staggered pattern with respect to the sheet conveyance direction. The only difference is the use of.
The conveyance belt 82E is in contact with the grip roller 81 and the paper S only in the convex portion, and therefore the linear velocity of the conveyance belt 82E is the thickness of the conveyance surface 82a, which is a convex portion (a flat surface / flat portion in this modification). Determined by (thickness). Since the concave portion 82b (bottomed hole portion in the present modification) has a small thickness, the apparent rubber hardness of the conveyor belt 82E is smaller than that of the conveyor belt 82 having a uniform thickness over the entire surface.

  Therefore, according to the fifth modification, the apparent conveyance belt is formed by using the conveyance belt 82E in which the shape of the conveyance surface 82a in contact with the leading edge of the sheet S is formed in a substantially staggered pattern in the sheet conveyance direction. The rubber hardness of 82E can be lowered, and the tension when the conveyor belt 82E is extended and used can be kept low. In addition, the same advantages and effects as those of the first modification are also obtained.

  It is not limited to the conveyor belts 82A to 82E shown in the first to fifth modifications, but has an irregular shape on the conveyance surface such that the apparent rubber hardness of the conveyance belt is small and low, and the leading edge of the paper S is obstructed. Any irregular shape may be used as long as it does not give the above.

  As described above, the belt conveying means 8 and 8A of each of the sheet conveying apparatuses 5 and 5A shown in FIGS. 1 to 4, 7 to 10, and 11 to 23 are the second conveying means 7 (the nipping conveying means). ) Is held in contact with or in contact with the leading edge or leading edge of the paper (sheet), which is a term having a broad meaning including the leading edge, leading edge surface, and the corner / edge of the leading edge) Depending on the degree of rigidity of the paper, it can be said that it is an example of a movement guide means for moving and guiding the paper S toward the nip portion (clamping portion) with the grip roller 81 while gradually increasing the contact area. 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 portion of the fixing device 11 in the apparatus main body. A sheet conveying device (for example, see FIG. 23B) configured to discharge the discharged sheet S from the apparatus main body to the 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 embodiments and modifications, the example in which the different paper (sheet) conveyance directions are changed from the substantially horizontal direction to the upward direction in the vertical direction (substantially upward in the vertical direction) has been described. Without being limited, it is changed from substantially horizontal to downward in the vertical direction (substantially vertical downward), or from downward in the vertical direction or upward to substantially horizontal (for example, FIG. 23A). 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 means, the second conveying means, and the pickup roller are not limited to those described above, but are substantially long cylindrical roller members that secure a predetermined length in the longitudinal direction of each rotating shaft. The roller member may be a short cylindrical roller member, 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, the guide surfaces formed by several guide members in the outer direction and the inner direction in each of the above-described embodiments are positioned in the above-described several intervals where no roller member or roller member is arranged. 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 paper (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 performs batch transfer onto a sheet. Needless to say, the endless belt-like photoreceptor can be similarly applied to a single image forming apparatus.
The present invention relates to a sheet conveying apparatus for conveying a sheet (paper) from a sheet storage means (paper feed tray) or a sheet stacking means (paper feed table) to a printing unit main body in a printing apparatus including a stencil printing machine. May also be applied.

In the copying machine 1 as the image forming apparatus described above, a document to be read is set manually, but an ADF (automatic document feeder) for automatically reading a plurality of documents (sheets) is provided. The sheet conveying apparatus of the present invention may be applied to the ADF in an equipped copying machine, printing apparatus, or the like.
Further, the image forming apparatus is not limited to a copying machine, but is a facsimile, a printer, an ink jet recording apparatus, an image reading apparatus mainly having an image reading function having a scanner for reading an image from a document, or at least of them. You may apply to the compound machine etc. which combined 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, targeting a variety of sheet types as paper types. A sheet conveying apparatus.

  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, examples, and modifications of the present invention are the first to third examples of the invention of the prior application, and modifications thereof. It will be apparent to those skilled in the art that various embodiments, modifications, and examples can be configured within the scope of the present invention depending on the necessity and application.

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. FIG. 3 is an enlarged cross-sectional view of a main part of the paper transport device for explaining the first embodiment. 6 is a graph for explaining a test result related to variation in paper-type transport time in Example 1. FIG. 9 is a diagram showing a modification of the paper transport apparatus to which the present invention is applied, in which (a) is an example in which belt transport means is provided in the first transport means, and (b) is first and second transport means. Both of these means are provided with belt conveying means, respectively, and (c) is an example in which the belt conveying means is provided separately from the first and second conveying means. 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. 8 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 apparatus of FIG. 7. FIG. 8 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. 7. It is a schematic expanded sectional view which mainly shows another paper conveyance apparatus to which this invention is applied. FIG. 3 is a simplified perspective view showing a drive mechanism in the paper conveying apparatus of the first embodiment. It is a schematic front view of the principal part of FIG. FIG. 3 is a perspective view of a main part when a belt conveyance unit and a conveyance guide member are viewed from the grip roller side in the paper conveyance device of the first embodiment. FIG. 3 is a cross-sectional view of a main part around first and second transport means in the paper transport device of the first embodiment. FIG. 4 is a perspective view of the belt conveyance unit and its surroundings in the paper conveyance device according to the first embodiment when viewed from the grip roller side. FIG. 3 is a perspective view of the periphery of a belt conveyance unit in the paper conveyance device according to the first exemplary embodiment when viewed from the back side of a conveyance guide member. It is sectional drawing of the principal part around the 2nd conveyance means in the paper conveying apparatus of 1st Embodiment. FIG. 6 is a perspective view of a main part of a belt conveying unit showing a shape of a conveying surface of a conveying belt in a sheet conveying apparatus showing a first modification of the first embodiment. (A) is a perspective view of the principal part of the belt conveyance means which shows the shape of the conveyance surface of the conveyance belt in the paper conveyance device showing the modification 2 of the first embodiment, and (b) is the center of the upper pulley shaft. FIG. It is a perspective view of the principal part of the belt conveyance means which shows the shape of the conveyance surface of the conveyance belt in the paper conveyance apparatus which shows the modification 3 of 1st Embodiment. It is a perspective view of the principal part of the belt conveyance means which shows the shape of the conveyance surface of the conveyance belt in the paper conveyance apparatus which shows the modification 4 of 1st Embodiment. It is a perspective view of the principal part of the belt conveyance means which shows the shape of the conveyance surface of the conveyance belt in the paper conveyance apparatus which shows the modification 5 of 1st Embodiment. (A), (b) is a simplified front view for explaining an arrangement example of the first and second conveying means of the sheet conveying apparatus according to the difference in the sheet conveying path.

Explanation of symbols

1 Copying machine (image forming device)
2 Image forming apparatus body 3 Paper feeding device 4 Document reading device 5, 5 A Paper conveying device (sheet conveying device)
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 22 Drive mechanism 23 Paper feed motor 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)
62 Reverse roller (the other of the opposing pair of the first conveying means)
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)
72a Guide surface 72b Conveyance guide rib 73 Conveyance guide member (for forming an inlet from the paper feed tray to the conveyance path)
79 opening and closing Guide
8 0 Housing (Sheet conveying device body)
81 Grip roller (one of the opposite pair of the second conveying means, the rotation conveying driving means, the rotation conveying driving member)
81a Grip roller rotational drive shafts 82, 82A, 82B, 83C, 82D, 82E Conveying belt (belt as the other of the opposed 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, belt holding 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, belt holding rotating member)
84a, 84b Pulley shaft 86 Belt support member (support member)
91, 92 Spring (biasing means)
A First transport path (transport path)
B Second transport path (transport path)
R1 transport path R2 manual feed path R3 reverse transport path S paper (sheet / sheet-like recording medium, image forming medium)
Y Paper width direction (sheet width direction)
θ Entry angle

Claims (12)

First conveying means for conveying a sheet;
A second conveying unit that is arranged downstream of the first conveying unit in the sheet conveying direction and 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
At least the second transport unit of the first transport unit and the second transport unit is a sandwich transport unit that forms a sandwiching unit that sandwiches and transports the sheet.
One of the opposed pairs of the holding and conveying means in the second conveying means is a rotary conveying driving means capable of transmitting a driving force by rotating,
The other of the opposing pair is disposed in the outer direction of the sheet conveyance path formed between the first conveyance unit and the second conveyance unit, and is driven by the rotation conveyance drive unit toward the clamping unit. movement guide means der to move and guide the seat Te is,
The rotational transport driving means is composed of a roller-shaped rotational transport driving member,
The movement guide means comprises belt conveying means comprising a belt that directly rotates in contact with the rotary conveyance driving member,
The belt conveying means includes the belt made of an elastic member, and at least a pair of belt holding and rotating members that hold the belt so that the belt can run.
The pair of belt holding and rotating members are supported by open / close guides that are openable and closable with respect to the sheet conveying apparatus body,
The rotary transport driving member is supported by the sheet transport apparatus main body,
The sheet conveying apparatus , wherein the opening / closing guide includes urging means for urging the belt holding and rotating member via the belt in a direction in which the belt holding and rotating member is in pressure contact with the rotary conveyance driving member . The belt conveying means includes a support member that rotatably supports each belt holding and rotating member,
Each belt holding and rotating member is pivotally supported by the support member so as to keep the distance between the axes constant.
The shafts of the belt holding and rotating members are arranged on the support member so that the circumference of the belt when the belt is wound between the belt holding and rotating members is larger than the circumference of the belt alone. The sheet conveying apparatus according to claim 1. The sheet conveying apparatus according to claim 2 , wherein the belt is made of rubber having a rubber hardness of 30 to 60 degrees on a JIS A scale . The belt moves and guides the sheet while maintaining a state of being in contact with the leading end of the sheet, and a drawing process is performed on a conveying surface of the belt that is in contact with the leading end of the sheet. Item 4. The sheet conveying apparatus according to Item 3 . The belt, while maintaining the contact with the leading end of the sheet be those sheets moving-guiding, the shape of the conveying surface of the belt in contact with the leading end of the sheet, substantially parallel to the sheet conveying direction The sheet conveying apparatus according to claim 3 , wherein the sheet conveying apparatus is formed to be uneven along the direction . The belt, while maintaining the contact with the leading end of the sheet be those sheets moving-guiding, the shape of the conveying surface of the belt in contact with the leading end of the sheet, substantially perpendicular to the sheet conveying direction The sheet conveying apparatus according to claim 3 , wherein the sheet conveying apparatus is formed to be uneven along the direction. The belt, while maintaining the contact with the leading end of the sheet be those sheets moving-guiding, the shape of the conveying surface of the belt in contact with the leading end of the sheet, substantially skew with respect to the sheet conveying direction The sheet conveying device according to claim 3 , wherein the sheet conveying device is formed in a concavo-convex shape along the direction of the sheet. The belt, while maintaining the contact with the leading end of the sheet be those sheets moving-guiding, the shape of the conveying surface of the belt in contact with the leading end of the sheet, a substantially staggered with respect to the sheet conveying direction The sheet conveying apparatus according to claim 3 , wherein the sheet conveying apparatus is formed in an uneven shape. Sheet meters basis weight sheet conveying device according to any one of claims 1 to 8, characterized in that a strong sheet having waist 256~300g / m ^2. Image reading apparatus characterized by having a sheet conveying apparatus according to any one of claims 1 to 9. An image forming apparatus, comprising an image reading apparatus of a sheet conveying apparatus and / or claim 10, wherein according to any one of claims 1 to 9. Wherein the image forming apparatus, a copying machine, a facsimile machine, a printer, any one of a printing machine and an ink jet recording apparatus or the image forming according to claim 11, characterized in that these at least MFP which combines two, apparatus.

Images