JP2008162785A - Sheet carrying device, image reading apparatus, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet carrying device capable of preventing the buckling and jam of a sheet which is carried from a lower-stage feeding stage or the like through a second sheet carrying passage caused by the collision of the sheet with a carrying belt, and surely gripping and holding the sheet which is carried by a first carrying means through a first carrying passage on a belt carrying face. <P>SOLUTION: The belt carrying means 8A is disposed so that the belt carrying face 82a is projected from a vertical carrying guide face 72a toward the outside (a center side of the second carrying passage B). In the projection amount d of the belt carrying face 82a, when the downstream end 71b of an outline guide face 71a is used as a boundary, the projection amount d of the carrying face 82a positioned upstream of the second carrying passage B is smaller than that of the carrying face 82a positioned downstream of the second carrying passage B. A pulley 84 is disposed inside the vertical carrying guide face 72a so that the outer peripheral face of the pulley 84 is not projected from the vertical carrying guide face 72a to the outside. <P>COPYRIGHT: (C)2008,JPO&INPIT

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 body The conveying means also tends to be downsized. Hereinafter, the sheet storing means for storing the sheet will be described as a representative. In the present invention, the sheet storage means includes a sheet stacking means as a paper feed table.

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

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

Hereinafter, the reference numerals shown in the drawings of the above-mentioned Japanese Patent Application Laid-Open No. 2004-338923 will be described with parentheses as appropriate, and the sheet (P) in the paper feed tray (1) will be 1 in the well-known FRR separation system. 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, causing jams and poor conveyance, resulting in a failure to perform a stable feeding operation.

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

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

It has the 1st, 2nd conveyance means comprised like the said Unexamined-Japanese-Patent No. 2004-338923 (patent document 1), and it is 2nd between a 1st conveyance means and a 2nd conveyance means. 2. Description of the Related Art 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 brought into contact with the roller. A sheet inverting means provided in a forming apparatus is known (for example, see Patent Document 4).
According to this sheet reversing means, the fed sheet is in the above-mentioned direction changing portion, and the inner contact portion always comes into contact with the roller, and this roller is driven to rotate as the sheet is conveyed in the conveying direction. Compared to the conventional guide plate, the conveyance resistance can be reduced, that is, the frictional resistance generated between the fixed guide member and the moving sheet is eliminated, and the guide for changing the conveyance direction at the direction changing portion. I can do it.

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

However, in the sheet conveying 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.

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

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

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

  The present invention provides a sheet conveying apparatus capable of solving the later-described problems (problems) to be improved when the prior invention is put into practical use, an image reading apparatus provided with the sheet conveying apparatus, a sheet conveying apparatus and / or an image. It is a main object to realize and provide an image forming apparatus including a reading device. Since the explanation of the problem is based on the invention of the prior application, the example of the invention of the prior application will be described and will be described in detail with reference to FIGS. 17 (a), 18 (a) and the like. In addition to the above, the present invention provides a sheet conveying apparatus capable of obtaining the advantages and effects described in the following claims and the embodiments and modifications described later, an image reading apparatus including the sheet conveying apparatus, and a sheet conveying apparatus. Another object of the present invention is to realize and provide an image forming apparatus including an image reading apparatus.

  In order to solve the above-mentioned problems and achieve the above-mentioned object, the present inventors have conducted research and evaluation as described in the examples of the prior application invention described below, Examples, etc. As a simple configuration that can transport relatively rigid sheets, such as cardboard and envelopes, without causing poor transport or jamming, regardless of the type of sheet, the simple design of a moving guide means (moving guide) was conceived. As a specific means, the belt conveying means having the simplest configuration has been variously devised and put into practical use. The present invention has been made on the basis of the results supported by such tests.

In order to solve the above-described problems and achieve the above-mentioned object, the invention according to each claim employs the following characteristic means / invention-specific matters (hereinafter referred to as “configuration”).
According to the first aspect of the present invention, a first conveying unit that conveys a sheet, and a sheet that is disposed downstream of the first conveying unit in the sheet conveying direction and that has been conveyed by the first conveying unit is the first conveying unit. A first conveying unit formed between the first conveying unit and the second conveying unit, and a second conveying unit that forms a nipping unit for nipping and conveying the sheet in a sheet conveying direction different from the sheet conveying direction of the first conveying unit. The second sheet conveying path, the second sheet conveying path different from the first sheet conveying path, the first sheet conveying path, and the second sheet conveying path. A belt conveyance means comprising: a sheet conveyance path, a merge conveyance path that merges upstream of the second conveyance means; and a belt that is disposed in an outer direction of the merge conveyance path and conveys the sheet toward the clamping unit And a first conveying means and the belt conveying A first outer guide surface disposed in the outer direction of the first sheet conveying path between the first stage and the first outer guiding surface for guiding the sheet conveyed from the first conveying means to the conveying surface of the belt; An outer guide member and a second outer guide surface arranged in the outer direction of the second sheet conveying path and guiding the sheet conveyed from the upstream side of the second sheet conveying path to the conveying surface of the belt. A first belt holding and rotating member disposed opposite to the clamping portion for holding the belt and the belt so as to be able to travel. And a second belt holding and rotating member disposed on the upstream side of the second sheet conveying path so as to face the second sheet conveying path, and the first conveying means includes a pair of rotating members that nipping and conveying the sheet. , Second belt holding rotation unit Is a downstream side of the second sheet conveying path from the axial center of the rotating member provided on the outer surface of the first conveying means, and a second sheet conveying path from the downstream end of the first outer guide surface. The belt conveying means is arranged such that a conveying surface of the belt protrudes outward from the second outer guide surface, and a second conveying surface of the belt is arranged. The amount of protrusion from the outer guide surface of the second sheet is downstream of the second sheet transport path from the transport surface located upstream of the second sheet transport path, with the downstream end of the first outer guide surface as a boundary. The sheet conveying apparatus is characterized by being arranged so as to increase the number of the conveying surfaces positioned on the side.

  According to a second aspect of the present invention, in the sheet conveying apparatus according to the first aspect, the outer peripheral surface of the second belt holding and rotating member is disposed inside the second outer guide surface. .

  According to a third aspect of the present invention, in the sheet conveying apparatus according to the first or second aspect, the belt conveying unit includes a second sheet conveying path at least on a downstream surface of the first outer guide surface, the conveying surface of the belt. It is arrange | positioned so that it may be located in the downstream of 2nd outline guide surface outside.

  According to a fourth aspect of the present invention, in the sheet conveying apparatus according to any one of the first to third aspects, the belt conveying means is configured such that the leading end portion of the sheet passing through the second sheet conveying path is formed on the belt. It arrange | positions so that it may approach and contact with an acute rush angle with respect to a conveyance surface.

  According to a fifth aspect of the present invention, a first conveying unit that conveys a sheet and a sheet that is disposed downstream of the first conveying unit in the sheet conveying direction and that has been conveyed by the first conveying unit is the first conveying unit. A first conveying unit formed between the first conveying unit and the second conveying unit, and a second conveying unit that forms a nipping unit for nipping and conveying the sheet in a sheet conveying direction different from the sheet conveying direction of the first conveying unit. The second sheet conveying path, the second sheet conveying path different from the first sheet conveying path, the first sheet conveying path, and the second sheet conveying path. A sheet conveying path, a merging conveying path that merges on the upstream side of the second conveying means, and a belt that is arranged in a contour direction of the merging conveying path and conveys the sheet toward the clamping unit, Three or more are intermittently arranged in the direction And an outer guide surface that is arranged in the outer direction of the second sheet conveying path and guides the sheet conveyed from the upstream side of the second sheet conveying path to the conveying surfaces of the three or more belts. Each belt conveying means includes a belt, and a first belt holding and rotating member disposed to face the holding portion for holding the belt so that the belt can run. A second belt holding and rotating member disposed on the upstream side of the second sheet conveying path is provided opposite thereto, and is disposed at the center of the three or more belt conveying means in the sheet width direction. The belt of the belt conveying means is formed longer in the second sheet conveying path direction than the belt of the other belt conveying means, and the outer peripheral surface of the second belt holding and rotating member in the other belt conveying means Of the above The protruding amount from the contour guide surface and the center belt conveying means arranged corresponding to the protruding position from the outer contour guide surface of the outer peripheral surface of the second belt holding and rotating member in the other belt conveying means. The sheet conveying apparatus is characterized in that the three or more belt conveying means are arranged so that a protruding amount of the conveying surface of the belt from the outer guide surface is substantially the same.

  According to a sixth aspect of the present invention, in the sheet conveying apparatus according to any one of the first to fifth aspects, the leading edge of the sheet with respect to the conveying surface of the belt at the leading edge of the sheet conveyed by the first conveying means A rush angle varying means for displacing the belt conveying means in a direction to change the rush angle of the section, and the belt conveying means allows the sheet to be conveyed from the second sheet conveying path and is in the initial arrangement state. It is configured to be freely displaceable between a position and a position where the entry angle is smaller than the initial position. When the sheet is conveyed from the second sheet conveyance path, the entry angle variable means is used. Displacement of the belt conveying unit is prohibited, and the belt conveying unit is held at the initial position.

  According to a seventh aspect of the present invention, there is provided the sheet conveying apparatus according to the sixth aspect, wherein at least before the leading end of the sheet conveyed from the first sheet conveying path abuts against the conveying surface of the belt, the rushing is performed. An angle variable means is used to displace the belt conveying means in a direction in which the entry angle is reduced.

  According to an eighth aspect of the present invention, in the sheet conveying apparatus according to the sixth or seventh aspect, after the leading edge of the sheet conveyed from the first sheet conveying path is nipped by the nipping portion, the rush angle varying means Then, the belt conveying means is returned to the initial position.

  According to a ninth aspect of the present invention, in the sheet conveying apparatus according to any one of the sixth to eighth aspects, the trailing end of the sheet conveyed from the first sheet conveying path is configured at least other than the belt. Before exiting the guide means, the rush angle varying means is used to displace the belt conveying means in a direction in which the rush angle is reduced.

  According to a tenth aspect of the present invention, in the sheet conveying apparatus according to any one of the sixth to ninth aspects, a solenoid is used as a driving unit of the rush angle varying unit.

  The invention according to claim 11 is the sheet conveying apparatus according to any one of claims 6 to 9, wherein a driving motor that is rotationally driven by pulse input is used as the driving means of the rush angle varying means. And

  According to a twelfth aspect of the present invention, in the sheet conveying apparatus according to the sixth or seventh aspect, the first conveying means includes a pair of rotating members each having a rotation shaft for nipping and conveying the sheet. Any one of the rotating shafts and the entry angle varying means are connected via at least one torque limiter.

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

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

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

According to the present invention, it is possible to realize and provide a novel sheet conveying apparatus, an image reading apparatus having the sheet conveying apparatus, a sheet conveying apparatus and / or an image forming apparatus having an image reading apparatus by solving the problems described below. The specific effects of each claim are as follows.
According to the first, second, and thirteenth aspects, the second belt holding and rotating member is located downstream of the second sheet conveying path from the axial center of the rotating member provided on the outer periphery of the first conveying means. The belt conveying means is disposed on the upstream side of the second sheet conveying path from the downstream end of the first outer guide surface, and the belt conveying means has the belt conveying surface facing outward from the second outer guide surface. And the amount of protrusion of the belt conveyance surface is located on the upstream side of the second sheet conveyance path with the downstream end of the first outer guide surface as a boundary. By disposing the belt on the downstream side of the second sheet conveyance path so that the conveyance surface of the belt is increased, the first conveyance unit conveys the belt via the first sheet conveyance path. Sheet (especially cardboard) Since the leading edge of the sheet, the same applies hereinafter), the belt conveying surface protrudes to the extent that the leading edge of the sheet does not collide with the second outer guide surface when elastically deforming the conveying surface of the belt. By selecting the belt material, it is possible to stably convey the sheet, and it is possible to prevent the noise generated by the front end of the sheet colliding with the second outer guide surface. Further, the second belt holding and rotating member is disposed on the inner side of the second outer guide surface so that the outer peripheral surface thereof does not protrude outward from the second outer guide surface. It is possible to prevent the leading edge of the sheet conveyed from the upstream side of the path from colliding with the belt conveyance surface of the portion held by the second belt holding rotation member.

  According to the third and thirteenth aspects of the present invention, the belt conveying means includes the second outer guide in which the belt conveying surface is at least downstream from the downstream end of the first outer guide surface on the second sheet conveying path. Since the front end of the sheet conveyed from the first conveying means bites in while causing elastic deformation, the front end of the sheet is placed on the second outer guide surface. Collisions can be prevented in advance.

  According to the fourth and thirteenth aspects of the present invention, the belt conveying means is arranged so that the leading end portion of the sheet passing through the second sheet conveying path enters and contacts with an acute rush angle with respect to the belt conveying surface. Since it is arranged, the leading edge of the sheet conveyed from the second sheet conveying path can be reliably guided to the clamping unit of the second conveying means.

  According to the fifth and thirteenth aspects of the invention, the belt conveying means disposed at the center in the sheet width direction among the three or more belt conveying means disposed in the sheet width direction is more than the other belt conveying means. Is formed long in the second sheet conveying path direction, and the amount of protrusion of the outer peripheral surface of the second belt holding and rotating member in the other belt conveying means from the outer guide surface and the second belt conveying means in the second belt conveying means. The amount of protrusion of the belt conveying surface from the outer guide surface in the central belt conveying means arranged corresponding to the protruding position of the outer peripheral surface of the belt holding rotating member from the outer guide surface is substantially the same. Since the two or more belt conveying units are arranged, the leading edge of the sheet conveyed from the second sheet conveying path can be reliably guided to the holding unit of the second conveying unit.

  According to the sixth, seventh, and thirteenth aspects of the present invention, when the sheet conveyed by the first conveying unit is conveyed to the clamping unit of the second conveying unit, the entry angle is reduced by the above configuration. For example, a first outer guide member that constitutes a first sheet conveyance path by assisting sheet conveyance while further reducing the rush load of the sheet on the conveyance surface of the belt by the displaced belt. In addition, it is possible to further reduce the conveyance resistance received from the outer guide member and to perform a more stable feeding / conveying operation.

  According to the eighth and thirteenth aspects of the present invention, after the leading edge of the sheet conveyed from the first sheet conveying path is nipped by the nipping portion, the rush angle varying means is used to bring the belt conveying means to the initial position. By returning, a sufficient conveying force is applied to the sheet by the conveyance by the clamping unit, so that the sheet can be smoothly conveyed. Therefore, the driving means (driving source) of the entry angle varying means Can save energy.

  According to the ninth and thirteenth aspects of the present invention, the rush angle varying means is provided before the trailing edge of the sheet conveyed from the first sheet conveying path passes through at least the guiding means constituted by other than the belt. By displacing the belt conveying means in the direction in which the rush angle becomes smaller, the impact when the rear end or rear end of the sheet comes into contact with the belt can be mitigated, and the splash sound at the rear end of the sheet can be reduced.

  According to the tenth and thirteenth aspects of the present invention, it is possible to reduce the cost of the apparatus by using an inexpensive and easy-to-control solenoid as the driving means for the rush angle varying means.

  According to the eleventh and thirteenth aspects of the present invention, a drive motor (for example, a stepping motor) that is rotationally driven by pulse input is used as the drive means for the rush angle varying means, so that the rush angle can be changed (or switched). This is possible at high speed, and can be handled even in the apparatus / sheet passing mode in which the sheet interval time is small. Also, since the speed (or switching speed) control when changing the rush angle is easy, the rush angle changing speed (or switching speed) when the rear end or the rear end of the sheet comes into contact with the conveyance surface of the belt. ) Is made slower, it is possible to further reduce the impact at the time of contact.

  According to the twelfth and thirteenth aspects of the present invention, any one of the pair of rotating shafts constituting the first conveying means and the rush angle varying means are connected via at least one torque limiter, thereby Because the displacement operation of the rush angle varying means is performed in synchronization with the rotation of one of the shafts (for example, the shaft of the feed roller or the shaft of the reverse roller), it is not necessary to use an electromechanical component such as a solenoid or a stepping motor. It is possible to realize cost reduction and energy saving of the device.

  According to the fourteenth aspect of the present invention, as an image reading apparatus having the sheet conveying apparatus according to any one of the first to thirteenth aspects, a recording paper, envelope, coated paper, such as thick paper with a simple configuration, which is strong In addition to being able to stably convey a relatively high-strength original sheet such as special paper as well as to realize and provide a low-cost image reading apparatus, it is possible to realize and provide an image reading apparatus that exhibits the effects of the above-described inventions. .

  According to the fifteenth aspect of the present invention, the sheet conveying apparatus according to any one of the first to thirteenth aspects conveys a stiff recording paper such as cardboard and a special paper such as an envelope or coated paper with a simple configuration. The image forming apparatus according to any one of claims 1 to 13 and / or the image reading apparatus according to claim 14 can be realized by providing a low-cost image forming apparatus that can stably perform image processing. As an image forming apparatus having the apparatus, it is possible to realize and provide an image forming apparatus that exhibits the effects of the above inventions.

  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 16 and the like, including FIGS. 1 to 3 and the like, include examples of the sheet conveying apparatus to which the invention of the prior application is applied and an image forming apparatus equipped with the sheet conveying apparatus. Will be described in detail. First, an overall configuration of a copying machine 1 as an example of an image forming apparatus will be described with reference to FIG.

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

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

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

That is, the developing device 12 has an appropriate well-known configuration such as a developing roller that generates a toner brush in which toner particles are erected radially from the surface thereof, and is generated at a predetermined location on the surface of the photoreceptor 10A. The toner particles at the tip of the toner brush are attached to the latent image that moves around the circumference and passes through the developing position with the rotation of 10A, and the invisible latent image is visualized as a monochrome toner image.
The transfer device 13 includes two support rollers 15 and 16 that are opposed to each other with a predetermined spacing in a substantially vertical direction, and a transfer belt 17 that is an endless belt stretched between the support rollers 15 and 16. Then, the toner image on the outer peripheral surface of the photoreceptor 10A is transferred to the sheet S, and the sheet S on which the unfixed toner image is transferred is conveyed to the downstream side of the conveyance path R1. That is, the lower support roller 16 has its portion around which the transfer belt 17 is wound pressed against an approximately right diagonally lower portion of the photoconductor 10A, and the transfer belt 17 is transferred to a location where the surface of the photoconductor 10A and the transfer belt 17 are in contact with each other. 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 either or both of the configurations of a rotating brush that rotates following the rotation of 10A, and removes toner, foreign matter, and the like 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 therewith is driven to rotate, and at a place where both the rollers 31 and 32 are in contact, a predetermined heating temperature is set. 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 composed of a toner bottle or the like that stores new or new toner. A toner transport path (not shown) is formed from the toner storage container 20 to the developing device 12. When the developing device 12 consumes its own toner for development and becomes insufficient, new toner is replenished from the toner container 20 to the developing device 12.

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

The document reading device 4 has a reading device main body 4A that forms the framework, and a contact glass 57 is disposed over a predetermined range on the upper surface of the reading device main body 4A. In the reading 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. The reading means includes at least the first traveling body 53, the first traveling body 53, and the like. 2 is mainly composed of a traveling body 54, an imaging lens 55, and a reading sensor 56 such as a CCD.
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, the toner image is transferred onto the paper S by the transfer device 13.

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

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

(First example)
Next, a characteristic configuration of the sheet conveying apparatus 5 (hereinafter also referred to as “first example”) to which the sheet conveying apparatus according to the invention of the prior application is applied will be described.
As shown in FIGS. 2 and 3, the sheet transport device 5 has a large number of sheets S stacked and accommodated in a predetermined tray (lower in this example) of the paper feed tray 51 in the paper 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; It is mainly composed of a first conveyance path A as a curved first sheet conveyance path formed between the first conveyance means 6 and the second conveyance means 7.

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

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

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

As shown in FIGS. 3 and 4, the belt conveying means 8 includes a conveying belt 82, a grip roller 81 and a conveying belt 82 for holding the conveying belt 82 so as to be able to travel and winding the conveying belt 82. The roller-like pulley 83 as the first belt holding and rotating member disposed opposite to the nip portion of the roller, and the pulley 83 facing the pulley 83 and upstream of the second conveying means 7 in the sheet conveying direction. The roller-shaped pulley 84 as the second belt holding and rotating member disposed is mainly configured. In the present example, a single example of the second belt holding and rotating member is shown, but the present invention is not limited to this, and at least one or more may be provided.
The belt conveying unit 8 includes a conveying surface 82a (hereinafter, referred to as a conveyance surface 82a) of the conveying belt 82 excluding a portion of the conveying belt 82 held by the pulley 83 and the pulley 84 at the leading end of the sheet S conveyed by the first conveying unit 6. It is important to arrange so as to be in contact with / contact with the “belt conveying surface 82a”. 4, the shaft center of the pulley 84 (the center of the pulley shaft 84a) is higher than the lower end position of the reverse roller 62 and is higher than the height of the downstream end 71b of the outer guide surface 71a of the outer guide member 71. By disposing the belt conveying means 8 so as to be positioned below, the leading edge of the sheet S collides with the belly portion of the conveying belt 82 (the portion that should also be called “effective conveying surface”), A stable and appropriate elastic displacement / deformation state of the conveyance belt 82 is obtained, and the state in which the leading edge of the sheet S is securely in contact with the belt conveying surface 82a is held without causing repulsion of the leading edge of the sheet S. The effect of this can be obtained.
On the other hand, when the leading edge of the sheet S is arranged so as to be in contact (contact) with the conveyor belt 82 held by the pulley 83 and the pulley 84, the conveyor belt 82 contacts the pulley 83 and the pulley 84. The conveyance belt 82 portion that is held is generally harder than the belly portion of the conveyance belt 82 and is less elastically displaced and deformed. Therefore, when the leading edge of the paper S comes into contact with the portion, the repulsion occurs. 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 means 8 is arranged such that the leading edge of the paper S conveyed by the first conveying means 6 enters with an acute rush angle θ with respect to the belt conveying surface 82a. That is also important. By disposing the belt conveying means 8 in this way, the leading edge of the sheet S stably contacts the above-described antinode portion of the conveying belt 82, so that the leading edge of the sheet S reliably contacts the belt conveying surface 82a. This state is maintained, and the following effects can be obtained.
When the leading edge of the sheet S is arranged so as to enter the belt conveying surface 82a with a substantially perpendicular or right angle of incidence θ, the contact state of the leading end portion of the sheet S with the belt conveying surface 82a is unstable. For example, it is not preferable from the viewpoint of bending in the direction opposite to the traveling direction of the conveyor belt 82 or causing repulsion (the same applies hereinafter).

The paper feed trays 51 of each stage in the paper feed device 3 are formed in a substantially flat box shape with 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 in 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 the base end portion of the rising arm 52 can rotate within a predetermined angular range within the concave portion, that is, can swing, 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 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 of the bottom plate 50 in the drawing. Even when the sheets S are fed one by one and the number of stacked sheets decreases, the uppermost surface is maintained at a predetermined height.
As described above, the paper feed tray 51 is configured to be attachable / detachable / removable with respect to the main body of the paper feeder 3. That is, the paper feed tray 51 is inserted into the main body of the paper feeding device 3 as shown in FIG. It is configured to be able to selectively occupy the separation position where the paper S can be replenished or the size of the paper S can be exchanged by being pulled out / removed to the front side.
Further, at least the first transport unit 6, the second transport unit 7, and the paper transport path (transport path) disposed between the first transport unit 6 and the second transport unit 7 are when the paper feed tray 51 is pulled out. Left in the body. Therefore, in this example, it is an in-body discharge type image forming apparatus, but by providing the movement guide means, the above-mentioned conveyance path can be conveyed with the same curvature as the conventional one or less. Without increasing the size, the advantage of the in-body discharge type can be prevented from being reduced.

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

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

More specifically, the sheet feed separation mechanism using the FRR sheet feed method as the sheet separation mechanism is in contact with a feed roller 61 that is rotationally driven in a forward direction that advances in the sheet conveyance direction, and a lower side of the feed roller 61. , A reverse roller 62 that is 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, or the same support method as that of the pickup roller 60 can be used. Sometimes. In the outer peripheral portion including the outer peripheral surface of the feed roller 61, a rubber having a high coefficient of friction with respect to the paper S so that it can be easily sent out in the paper transport direction when it contacts the paper S, like the pickup roller 60. Such a soft high friction material is used. 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 metal core (not shown), and is rotatably supported by the housing 80 together with the reverse roller drive shaft 62a via the torque limiter.

In the FRR sheet feeding method, a weak torque in the reverse rotation direction with respect to the feed roller 61 is applied to the reverse roller 62 via a torque limiter (not shown). Accordingly, when the reverse roller 62 is in contact with the feed roller 61 or when one sheet S enters between the rollers 61 and 62, the reverse roller 62 rotates with the feed roller 61. That is, by the action of the torque limiter, for example, the reverse roller 62 slips with respect to the reverse roller drive shaft, and similarly to the feed roller 61, the reverse roller 62 rotates in the forward direction that advances in the paper feeding direction. On the other hand, when the feed roller 61 is separated or when two or more sheets S enter between the rollers 61 and 62, the reverse roller 62 rotates in the reverse direction. For this reason, when the multi-feed paper S enters, other paper S in contact with the reverse roller 62 other than one paper S in contact with the feed roller 61 which is the uppermost paper S is upstream in the paper transport direction. Thus, the double feeding of the paper S is prevented.
Accordingly, the conveyance force supplied from the reverse roller 62 to the sheet S in contact with the reverse roller 62 is sufficient to ensure the conveyance force in the reverse direction sufficient to return the sheet 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 rotary conveyance member of the second rotation conveyance member pair in the second conveyance means 7 is disposed obliquely above the feed roller 61 via a rotation drive shaft 81 a formed integrally with the grip roller 81. The housing 80 is rotatably supported. 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 and holds the conveyance belt 82 so as to run and rotate.

The arrangement of the belt conveying means 8 is not limited to the arrangement state described above, and may be as follows. That is, in FIG. 3, reference numeral 79 shown with parentheses indicates an open / close guide configured to be openable and closable with respect to the housing 80 as a part of the main body of the sheet conveying device 5. The opening / closing guide 79 is integrated (unitized) with an outer shell guide member 72 and a belt conveying means 8 which will be described later, and is configured as an opening / closing unit, such as a first conveying path A and a vertical conveying path extending substantially vertically upward. In order to make it easier for the user to handle paper jams, jams, etc., the conveyor belt 82 can be brought into and out of contact with the grip roller 81 around a hinge fulcrum shaft (not shown) below the housing 80. It is configured to be openable and closable.
When such an opening / closing guide 79 is provided, the pulley 83 and the pulley 84 are rotatably supported on the opening / closing guide 79 side together with the pulley shafts 83a and 84a. The opening / closing guide 79 shown in FIG. 3 and the like is shown in FIGS. 12 and 13 in an example to be described later, and the opening / closing guide 79 is provided with a belt conveying means 8A including a divided conveying belt 82. Compared to the belt conveying means 8A, a conveying belt 82 extending or divided along the sheet width direction so as to be in contact with at least the entire area or both side edges of the sheet S in the sheet width direction is used instead of the belt conveying means 8A. The main difference is that the belt conveying means 8 having the above is arranged.

Although the conveyance belt 82 is partially described above, it is an endless belt and is stretched between the pulleys 83 and 84. The distance between the shafts of the pulleys 83 and 84 is set in advance. The linear belt running surface (belt 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. More specifically, an urging means (not shown) (for example, see a compression spring 91 shown in FIG. 25 and the like described later) supports a bearing member (not shown) (see a spring receiving portion 90 shown in the later-described FIG. 25 and the like) that supports the pulley shaft 83a. By being mounted, the conveying belt 82 is urged in a direction in which it is pressed against the grip roller 81.
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 drive source such as an electric motor provided exclusively for rotational driving of the grip roller 81 is connected to a rotational driving shaft 81a of the grip roller 81 via a driving force transmission means (not shown) such as a gear or a belt. They are connected (for example, see FIGS. 10 and 11 showing examples described later). The grip roller 81 is rotationally driven by transmitting a rotational driving force at a predetermined rotational speed from the rotational driving source via the driving force transmitting means. Thus, the grip roller 81 is a drive roller, while the conveyor belt 82 in contact with the grip roller 81 and the pulley 83 that supports the contact portion of the conveyor belt 82 from the inside of the belt are grips as a drive roller. A driven belt driven by a belt is driven by the rotation of the roller 81, and a driven roller is driven to rotate through the driven belt. Of course, the pulley 84 is also a driven roller that is rotationally driven via the driven belt.
If it is not necessary to have the same effect as the example described later with reference to FIGS. 10 and 11, for example, the drive system for driving the grip roller 81 is removed from the drive mechanism 22 to remove the grip roller 81. May be driven, and the conveyance belt 82 side may be driven by a drive mechanism (not shown).

In FIGS. 2 and 3, reference numeral 70 denotes an inner portion arranged in the inner direction of the first conveying path A as a first sheet conveying path formed between the first conveying means 6 and the second conveying means 7. It is an inner guide member as a guide device. The inner guide member 70 is fixed to the housing 80. The inner guide member 70 is provided with a curved inner guide surface 70a that bulges substantially diagonally downward to the left in both figures and comes into contact with the paper S.
71 is disposed in the outer direction of the first conveying path A between the first conveying means 6 and the belt conveying means 8, and the sheet S conveyed from the first conveying means 6 facing the inner guide member 70. The first outer guide means and the outer guide member as the first outer guide member are provided with the outer guide surface 71a as the first outer guide surface for guiding the belt to the belt conveying surface 82a. The outer guide member 71 is fixed to the housing 80. The outer guide member 71 has an outer guide surface 71a as a first outer guide surface whose outer guide surface 71a is curved and fixed in a concave shape corresponding to the inner guide surface 70a of the inner guide member 70, and The inner shell guide member 70 is opposed to the inner shell guide surface 70a with a predetermined gap (opening interval). As described above, the inner guide surface 70a of the inner guide member 70, the outer guide surface 71a of the outer guide member 71 facing the inner guide surface 70a, and the belt transport surface 82a, the first transport means 6 and the A first transport path A is formed between the two transport means 7. The inner guide member 70 and the outer guide member 71 have a function of guiding the paper S to the downstream conveyance path including the belt conveyance surface 82a via the first conveyance path A.

  2 and 3, 72 is arranged on the outer side of the vertical conveying path approximately vertically upward from the second conveying means 7, and faces the inner guiding surface 70 a with a predetermined gap (opening interval). An outer guide member that includes the opposed vertical conveyance guide surface 72a and guides the sheet S conveyed from the conveyance belt 82 to the conveyance path substantially vertically above. Thus, the vertical conveyance path that communicates with the conveyance path R1 is formed by the vertical conveyance guide surface 72a of the outer guide member 72 and the inner guide surface 70a of the inner guide member 70. Reference numeral 73 denotes a conveyance guide member that forms a sheet conveyance path from the sheet feed tray 51 to the nip portion between the feed roller 61 and the reverse roller 62, and that forms an introduction port for guiding and entering the sheet S in the nip portion. is there. Further, the inner guide member 70 is curved to bulge substantially downward (on the outer guide member 71 side provided on the outer shell) across the line connecting the nip portions of the first transport device 6 and the second transport device 7. A surface (the inner guide surface 70a) is provided, and the degree of bulge is set such that the sheet S is gently curved so that the leading edge of the sheet S always reaches the belt conveyance surface 82a. .

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

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

More specifically, the leading edge of the sheet S that is nipped between the feed roller 61 and the reverse roller 62 and fed out from the nip portion first reaches the belt conveyance surface of the conveyance belt 82 as shown in FIG. And touch. Then, as shown in FIG. 3, the conveyance surface 82a is gradually curved from the leading end side of the sheet S along with the movement of the conveyance surface 82a in the sheet conveyance direction due to the traveling of the conveyance belt 82 in the direction of arrow a, and this curve progresses. Accordingly, the contact area between the belt conveyance surface 82a and the sheet 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 82a 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. This is given to the paper S to be sufficiently compensated. Accordingly, it is possible to prevent at least the occurrence of defective conveyance of the sheet S between the first and second conveying units 6 and 7 and prevent the sheet S from occurring at the nip portion of the second conveying unit 7. Can be reached.
On the other hand, since the belt conveying surface 82a extends continuously to the nip portion of the second conveying means 7 as it is, the leading end portion of the sheet S in contact with the belt conveying surface reaches the clamping portion reliably and smoothly and stably. It will be. In other words, even with a highly rigid paper S, the paper S is first conveyed by the first conveying means 6 while being gently curved to such an extent that the leading edge always comes into contact with the belt conveying surface 82a, and the leading edge of the paper S is conveyed by the belt. The leading edge of the sheet S is moved after obtaining a second conveying propulsion force that advances in the sheet conveying direction from the conveying surface 82a to the sheet S by active conveying guide action by the conveying surface 82a in contact with the surface 82a. The sheet S is bent more deeply so as to reach the holding portion of the second 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 82a, the conveyance driving force is replenished from the conveyance surface 82a to the sheet surface again, and the degree of curvature of the sheet S is gradually reduced, so that the sheet conveyance is continued. Can do. As a result, as the paper transport device 5, the paper S received by the first transport means 6 is reliably and stably transferred from the second transport means 7 to the downstream paper transport path regardless of the rigidity of the paper S. Can be sent out.

As described above, the belt conveying unit 8 is arranged in the outer direction of the first conveying path A formed between the first conveying unit 6 and the second conveying unit 7, and the belt conveying surface 82 a is the leading edge of the paper S. It has a function as a movement guide unit that moves and guides the sheet S toward the second conveyance unit 7 while maintaining the contact state.
In this example, the belt conveyance unit 8 as the movement guide unit also has a function of moving and guiding the conveyance direction of the sheet S in the direction toward the nip portion of the second conveyance unit 7 by the conveyance belt 82.

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

In the belt system, details of the belt conveying means 8 used in the comparative test and the main members around it (including the conventional system) are as follows.
Material of conveyor belt 82: Ethylene / propylene rubber (EPDM)
Conveyance belt 82 hardness: JIS K6253 A type 40 degrees Friction coefficient of conveyance belt 82 to paper: 2.6
Conveying belt 82 wall thickness: 1.5 mm
Pulley 83 diameter: 13 mm
Pulley 84 diameter: 7 mm
Spacing between pulleys 83 and 84: 13 mm (distance between pulley shafts 83a and 84a)
Expansion rate of the conveyor belt 82: 7%
Diameter of each roller 60, 61, 62, 81: All 20mm

  As a basic test condition, the weight of the paper (metric basis weight) is used as a substitute value for the strength of the paper (stiffness: stiffness). At a relative humidity of 50%, the sheets were fed from the same tray in the copying machine. Then, with the test conditions described below with reference to FIG. 4, a test for examining the variation (variation) in the conveyance time of each paper type was performed. FIG. 5 shows a test result of the variation in the conveyance time, and Table 1 shows a summary of the sheet passing state based on the test result of FIG.

  In FIG. 4, 88 is a paper feed sensor that detects the leading edge of the paper S picked up by the pickup roller 60, and 89 is a second conveying means 7 (belt system) or a grip roller 81 and a roller-like pulley 83. A vertical conveyance sensor for detecting the leading edge of a sheet conveyed by a pair (conventional method) is shown. The paper feed sensor 88 and the vertical conveyance sensor 89 are each composed of a reflective photosensor.

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

  In both the conventional method and the belt method, the pick-up pressure (feed pressure) by the pick-up roller 60 is changed to two types of 1.1N and 2.2N, and the driving-side feed roller 61 and the driving-side grip are changed. Both the linear speeds of the rollers 81 are the same 154 mm / s, and the arrival time of the leading edge of the paper transported through the transport path length 57 mm from the paper feed sensor 88 to the vertical transport sensor 89 is changed to five paper types, respectively. The graph of FIG. 5 shows the variation result of the paper type conveyance time measured by the oscilloscope.

From the test results shown in FIG. 5, when the metric basis weight is 256 g / m ² or more as the paper type, the conventional method has a large variation in the conveyance time (long conveyance time) and a large paper slip. In the belt system, it was found that the variation in the conveyance time is small (the conveyance time is not so long) and the slip of the paper is small. Further, it was found that the conveyance force decreases when the pickup pressure is reduced, but in the case of the belt system of the present invention, even if the pickup pressure is reduced, the conveyance time is not significantly affected. Therefore, when the belt system of the present invention is adopted, the pickup pressure can be reduced, so that the power of the drive motor can be reduced. As a result, the apparatus can be reduced in size.

Next, Table 1 that summarizes the sheet passing state based on the test results of FIG. 5 will be described.
Here, “metric basis weight” corresponds to the weight of one sheet of paper per square meter in grams when displaying the weight of paper or paperboard (paper). In general, a paper having a small basis weight is “light paper” or “thin paper”, and a paper having a large basis weight is “heavy paper” or “thick paper”.
In the test results in Table 1, “good paper passing” indicated by a circle means 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”, which is indicated by an X mark, indicates that the conveyance is good and the vertical conveyance sensor 89 is reached within a predetermined time after the paper feed sensor 88 is turned on and the leading edge of the paper is detected. This indicates that there was no conveyance, that is, a conveyance failure.

From the test results in Table 1, when the metric basis weight is 256 g / m ² or more as the paper type, the conventional method could not pass the paper, whereas the belt method according to the present invention shown in FIGS. All the papers passed. Thereby, the remarkable effect of the belt system according to the present invention was recognized.
According to the comparative observation of the sheet passing / conveying state, when the metric basis weight is 256 g / m ² or more in the conventional method, the sheet becomes stiff and difficult to bend along the curved sheet conveying path. 1 to 4, it was found that the leading edge of the sheet hits a roller-like pulley 83 that is in contact with the grip roller 81.
In addition, as a paper type, a paper having a metric basis weight of 256 g / m ² or more was subjected to a comparative observation of a sheet passing / conveying state using a paper whose surface portion was coated and a paper which was not coated. However, significant differences other than the test results in Table 1 were not recognized.

From the observation results of the paper conveyance process in Example 1 described above, the following was found. That is, when the highly rigid paper S having a metric basis weight of 256 g / m ² or more is conveyed from the first conveying means 6 to the belt conveying surface 82a of the belt conveying means 8 via the first conveying path A, the rigidity is increased. Therefore, the various guide members constituting the first transport path A are changed to simple shapes so as to reduce the transport load resistance, or various guide members are not required at all. It turns out that it is also possible.
Therefore, in the case of a sheet conveying apparatus that conveys using only the sheet S having relatively high rigidity, the essential components are the first conveying means 6, the second conveying means 7, the first and The second transport unit is disposed in the outer direction of the first transport path A (in this case, no guide member is formed) formed between the second transport units 6 and 7 and maintains a state in contact with the leading edge of the sheet S. Belt conveying means 8 (movement guiding means) for moving and guiding the paper S toward the paper 7.
From the above, the various guide members forming the first transport path A have relatively low rigidity, for example, when the paper S such as plain paper or PPC is transported, the straightness of the paper S with low rigidity is weak. It can be said that it is necessary to compensate for the straightness (which is straight ahead when compared to a sheet S having a relatively high rigidity such as a thick sheet) and to guide and guide it to the belt conveyance surface 82a. In other words, the first transport path A is formed in order to make the leading edge of the paper S abut against the belly portion of the belt transport surface 82a to compensate for the decrease in straightness as the rigidity of the paper S decreases. It can be said that there is a need to set the shape of the guide surfaces of the various guide members.
In other words, as the sheet S having higher rigidity (the sheet S having a larger metric basis weight) is used, the various guides used when configuring the sheet conveyance path of the curvature portion having the relatively small curvature radius described above. It becomes possible to give a degree of freedom to the design of the shape and arrangement of the members.
The material of the conveyor belt 82 is not limited to that used in the comparative test, and may be, for example, chloroprene rubber, urethane rubber, or silicon rubber. The rubber hardness of the conveyor belt 82 may be JIS K6253 A type 40 to 80 degrees.

  As described above, according to the paper conveyance device 5 and the copying machine 1 having the same shown in FIGS. 1 to 4, the paper type compatibility is achieved with a simple and low-cost device configuration while being compact and space-saving. A sheet conveying device and an image forming apparatus excellent in the above can be provided. In other words, basically, the conveyor belt is wound around the existing roller that constitutes the second conveying means, and the belt conveying means 8 is newly provided and added, and a dedicated drive source for the belt conveying means 8 is also provided. The sheet conveying device and the image forming apparatus can be realized at a low cost because of the extremely simple configuration.

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

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

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

  The paper transport device 5 shown in FIGS. 6 to 8 is a first transport device 5 formed between the first transport device 6 and the second transport device 7 as compared with the paper transport device 5 shown in FIGS. In addition to the conveyance path A, the second conveyance path B is formed from the upstream of the second conveyance means 7 to the second conveyance means 7, and serves as another independent second sheet conveyance path different from the first conveyance path A. The point which has, the 1st conveyance path A and the 2nd conveyance path B have the confluence conveyance path | route (henceforth a "merging conveyance path" or a "merging part") which merges in the upstream of the 2nd conveyance means 7, The main difference is that one belt conveyance means 8 of the second rotation conveyance member pair is arranged so as to be dislocated in the outer direction of the merge conveyance path of the first and second conveyance paths A and B. The paper transport device 5 shown in FIGS. 6 to 8 is the same as the paper transport device 5 shown in FIGS. 1 to 4 except for the differences.

That is, 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 freely separated from the pulley 83 by a predetermined distance so as to be 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. Accordingly, the leading edge of the sheet S conveyed on the first conveying path A by the first conveying means 6 always comes into contact with the belt conveying surface 82a and is conveyed on the second conveying path B by an unillustrated conveying means. The incoming paper S is not prevented from reaching the second transport means 7.
The outer guide member 71 is different from that of the first example shown in FIGS. 1 to 4 only in that a vertical conveyance guide surface 71c is formed on the right side surface in the drawing. The outer guide member 72 is arranged in the outer direction of the second transport path B extending downward from the vertical transport path described above, compared with that of the first example shown in FIGS. The only difference is that it functions as a second outline guide member having a longitudinal conveyance guide surface 72a as a second outline guide surface for guiding the sheet S conveyed from the upstream side of B to the belt conveyance surface 82a. As described above, the second conveyance path B is formed by the vertical conveyance guide surface 71c of the outer guide member 71 and the vertical conveyance guide surface 72a of the outer guide member 72 that is disposed opposite the guide surface 71c and has a predetermined opening interval. Has been.

Next, the conveying operation of the sheet conveying device 5 shown in FIGS. 6 to 8 will be described. Since the paper S is fed out and transported from the state of being horizontally stacked in the paper feed tray 51, the paper transport direction in the paper feed separation mechanism of the first transport means 6 is substantially horizontal, but thereafter it is positioned upward. In order to convey the image forming apparatus main body 2 to the image forming unit 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. 7, after separation of the sheets S one by one by the sheet feeding / separating mechanism, one sheet S is conveyed with a gentle bend so that the conveyance resistance is small, and the leading end thereof is the conveyance belt. 82 abuts.
Since the conveyor belt 82 is traveling so as to travel in a substantially vertical upward (substantially above) direction indicated by an arrow a in FIG. 7, the leading edge of the sheet S that contacts the conveyor belt 82 is illustrated in FIG. As shown in FIG. 8, the sheet is conveyed to the nip portion between the grip roller 81 and the conveyance belt 82, and is nipped and conveyed to the downstream side in the substantially vertical direction by the pair of the grip roller 81 and the conveyance belt 82. At this time, as described above, the sheet S is subjected to the conveyance propulsion force that is transmitted from the conveyance belt 82 in the conveyance direction and acts toward the nip portion between the grip roller 81 and the conveyance belt 82 by the conveyance belt 82. Therefore, even the highly rigid paper S can be stably conveyed without causing a conveyance failure.

  As described above, according to the paper conveyance device 5 shown in FIGS. 6 to 8, the paper conveyance device having the merging conveyance path is the same as the paper conveyance device 5 described with reference to FIGS. 1 to 4. Effects, that is, high-stiffness paper such as cardboard can be stably conveyed, has excellent paper type compatibility, and has at least two or more conveyance paths such as first and second conveyance paths A and B. The paper conveying apparatus can be applied in correspondence with the developed paper conveying apparatus, and the application range can be expanded, that is, the paper conveying apparatus excellent in model compatibility can be obtained.

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

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

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

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

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

As described above, according to the sheet conveying apparatus 5 of the third example, the rear end Se of the conveyed sheet S contacts the belt 82 at a position different from the position where the trailing edge Se contacts the belt conveying surface 82a. Since the tension roller 85 as a supporting contact member is disposed, when the sheet S is conveyed with a predetermined curvature, the trailing edge Se of the sheet S is located at the nip portion of the first conveying unit 6. When any of the guide members 71 comes off and collides with the conveyance surface 82a, the collision belt 82 can be sufficiently elastically bent to absorb the impact, Sudden sound (honeycomb) generated by a collision can be suppressed. That is, when the trailing edge Se of the sheet S is in contact with the belt conveyance surface 82a, the contact member does not hinder the deformation of the conveyance belt 82 where the trailing edge Se of the sheet S is in contact with the trailing edge Se of the sheet S. The conveyance belt 82 can be sufficiently bent in the contact direction.
In particular, when a highly rigid sheet S such as a thick sheet is conveyed, even if the rear 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, eliminating the user's uncomfortable feeling and avoiding misperception that a failure has occurred, improving the usability of the device. Can be made.

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

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

In the third example, the above-mentioned predetermined position is secured, and a tension roller is provided for securing tension by pressing and urging outward from 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 6 to 9 is configured as a nipping and conveying means for nipping and conveying the paper S. That is, the second transport means 7 is a second rotational transport composed of two rotationally transported members disposed opposite to each other, the grip roller 81, a roller-shaped pulley 83, and a transport belt 82 stretched between the roller-shaped pulleys 84. Although it has been described as a member pair configuration, the grip roller 81 side is the driving side, and the conveying belt 82 side is described as the driven side driven in contact with the grip roller 81, the drive / driven side is not necessarily clarified However, the technical contents include that the conveyance belt 82 side may be driven.
On the other hand, in the fourth example described below, the grip roller 81 side is defined as the driving side, and the conveying belt 82 side is defined as the driven side that is driven in contact with the grip roller 81 by the following contents. In the first embodiment, the grip roller 81 side is the driving side, and the conveyance belt 82 side is the driven side that is in contact with the grip roller 81 and is driven.

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

(Fourth example)
A fourth example will be described with reference to FIGS. FIGS. 10 and 11 simply show a drive mechanism 22 as a feed drive means (paper feed drive system) of the first transport means 6 and the second transport means 7 in the paper transport apparatus 5A of the fourth example. Yes. FIGS. 11 and 12 show the periphery of the belt conveying means 8A of the second conveying means 7 in the paper conveying apparatus 5A of the fourth example.
A sheet conveying apparatus 5A of the fourth example shown in FIGS. 10 to 12 is compared with the sheet conveying apparatus 5 shown in FIGS. 1 to 4 and FIGS. 7 and the belt conveying means 8A instead of the belt conveying means 8, and the conveyance belt 82 and the like are in contact with a part of the paper S in the paper width direction Y. The point which is comprised intermittently in the width direction Y is mainly different. The sheet conveying apparatus 5A of this example is the same as the sheet conveying apparatus 5 shown in FIGS. 1 to 4 and FIGS. 6 to 9 except for the differences described above.

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

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

  A plurality of grip rollers 81 are intermittently fixed and arranged on a rotational drive shaft 81a in the paper width direction Y in a skewered dumpling shape. On the other hand, the conveying belt 82 and the pulleys 83 and 84 of the belt conveying means 8A are disposed and arranged corresponding to at least one of the plurality of grip rollers 81 (that is, at least one of the opposed pairs). . Specifically, in the sheet conveying apparatus 5A shown in FIG. 12, three grip rollers 81 are arranged on the rotation drive shaft 81a, and further, one conveying belt corresponding to and facing the three grip rollers 81. 82 is disposed and arranged with a width substantially equal to that of the center grip roller 81. In FIG. 10, in order to clearly show the drive mechanism 22, the arrangement interval of the grip rollers 81 is intentionally shifted in the direction of the rotation drive shaft 81 a, but is shown to be uneven, but in reality, it faces the conveyance belt 82 and the pulley 83. Of course, they are arranged at equal intervals.

As shown in FIGS. 10 and 11, the drive mechanism 22 includes a paper feed motor 23 composed of a stepping motor as a single drive source and drive means, and a motor gear 24 fixed to the output shaft of the paper feed motor 23. The idler gear 25 meshed with the motor gear 24, the feed roller drive gear 61B meshed with the idler gear 25 and fixed to one end of the shaft 61a of the feed roller 61, the idler gear 26 meshed with the feed roller drive gear 61B, and the idler gear 26, and a feed roller gear 61A fixed to the other end of the shaft 61a near the feed roller 61, a feed roller gear 61A fixed to one end of the rotational drive shaft 81a of the grip roller 81, and the feed roller gear 61A. The above-described idler gear 65 that meshes with the roller gear 61A, and this Meshes with Idoragiya 65, is mainly composed of a pickup roller gear 60A which is fixed to the other end of the shaft 60a of the pickup roller 60 closer. The paper feed motor 23 is fixed to the housing 80. The idler gears 25, 26, and 65 are rotatably supported by the housing 80, respectively.
As described above, in this example, the paper conveyance device 5A is compact and space-saving, that is, as illustrated in the first embodiment, the first conveyance path A is configured with a curvature portion having a relatively small curvature radius. For this reason, the sheet feeding motor 23 is single and serves as the driving means for the first conveying means 6 and the second conveying means 7 and contributes to the compactness of the apparatus.
The reverse roller 62 is driven by a separate system that includes, for example, a solenoid that releases pressure on the feed roller 61 and the like. In FIG. 10, 62b represents what was demonstrated as the torque limiter which is not shown in the example shown in FIGS.

In the example shown in FIGS. 1 to 4, the rotational drive relationship between the pickup roller 60 and the feed roller 61 has been described in a simplified manner. 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. Here, however, the grip roller 81 is a rotary conveyance drive member. In order to clarify that this is the case, an example is shown in both figures.

(Fifth example)
A fifth example will be described with reference to FIG. In the fifth example, compared to the sheet conveying apparatus 5A shown in FIGS. 10 to 12, a configuration in which the conveying belts 82 are disposed in all the opposed pairs in the nipping and conveying means of the second conveying means 7, that is, The only difference is that a sheet conveying device 5B is used, in which three conveying belts 82 are disposed and arranged to face the three grip rollers 81 and have substantially the same width as the respective grip rollers 81. In other words, the conveying belt 82 of the three belt conveying means 8A faces the three grip rollers 81 and travels with the same relation to the pulleys 83 and 84 fixed to the same pulley shafts 83a and 84a. It is held and arranged freely. The sheet conveying apparatus 5B of the fifth example is the same as the sheet conveying apparatus 5A shown in FIGS. 10 to 12 except for the differences.

  Therefore, according to the fourth and fifth examples, it is possible to select one of the sheet conveying devices 5, 5A, and 5B by comparing the performance and the cost according to the user's request. As a matter of course, the cost of the sheet conveying apparatus 5A, which is partially constituted by one, is the lowest with respect to the full width of the conveying belt 82 in the sheet conveying apparatus 5, and then is partially constituted by three. The sheet transport device 5B is inexpensive. As described above, according to the fourth and fifth examples, when the full width configuration of the conveyance belt 82 in the sheet conveyance device 5 is the maximum performance, the performance and the cost can be compared and selected according to the performance required by the user. It becomes possible.

  In addition, the conveyance belt 82 of the belt conveyance means 8A in the fourth and fifth examples is pressed against the grip roller 81 where the pulley 83 is driven by a biasing force of a spring (not shown), and is driven to rotate by the drive mechanism 22. Since the gripper roller 81 is driven to rotate by being brought into direct contact with the grip roller 81, the linear velocity of the transport belt 82 is more varied when the grip roller 81 side is driven than when the transport belt 82 side is driven. Can be small. 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. Therefore, driving the grip roller 81 side rather than driving the conveyance belt 82 side can reduce variations in the linear velocity of the conveyance belt 82.

(Sixth example)
14 and 15 show a sixth example that is a modification of the fifth example. In the sixth example, as compared with the sheet conveying apparatus 5B in the fifth example shown in FIG. 13, instead of the sheet conveying apparatus 5B, as shown in FIGS. The contacting conveyance surface 82a is disposed so as to protrude a predetermined amount outward from the vertical conveyance guide surface 72a of the outer guide member 72, in other words, a paper conveyance path (continuous vertically upward to the second conveyance path B). The main difference is that a sheet conveying device 5C is used which clearly states that it is arranged and configured so as to protrude a predetermined amount toward the center of the sheet conveying path extending to the center of the sheet. The sheet conveying apparatus 5C of the sixth example is the same as the sheet conveying apparatus 5B except for the above-described points.

  As shown in FIG. 14, a conveyance guide rib 72b that also serves to reinforce and maintain the shape of the outline guide member 72 is provided on the longitudinal conveyance guide surface 72a other than the arrangement portion of the conveyance belt 82 in the paper width direction Y of the outline guide member 72. Projected from the longitudinal conveyance guide surface 72a to the outside of the sheet conveyance path (which is a sheet conveyance path extending in a substantially vertical direction continuously to the second conveyance path B) and extending in the substantially vertical and vertical directions. Has been. The belt conveying surface 82a grips the leading end of the thick paper by elastically deforming particularly thick paper (relatively high-stiffness paper) conveyed from the first conveying means 6 shown in FIG.・ Slightly with respect to the conveyance guide rib 72b over the upper and lower portions that are wound around the pulleys 83 and 83 so as to be held and conveyed to the nip portion of the second conveyance means 7 and form a substantially vertical surface. In order to be convex, it protrudes and is formed outward from the vertical conveyance guide surface 72a by a predetermined protrusion amount (also a step and dimension) d. Further, the conveyance guide ribs 72b are formed at a predetermined interval in the paper width direction Y so as to exhibit the advantages and effects described below. In FIG. 13, reference numeral 72c denotes an opening formed in the outer guide member 72 so as to expose the conveying belt 82 of the belt conveying means 8A to the center side of the sheet conveying path.

  In the sheet conveying apparatus 5 shown in FIGS. 1 to 4 and FIGS. 6 to 9, the conveying belt 82 contacts and corresponds to the entire width of the sheet, whereas the sheet conveying in the fourth and fifth examples. The partial contact as in the devices 5A and 5B is disadvantageous in terms of conveying force. However, as in the case of the sheet conveying apparatus 5C of the sixth example, a step with a protrusion amount d is provided between the conveying guide rib 72b formed at a predetermined interval in the sheet width direction Y and the belt conveying surface 82a, and the conveying is performed. By reducing the conveyance resistance caused by sliding between the guide rib 72b and the paper S as much as possible, it is possible to ensure a conveyance force substantially equal to that of the paper conveyance device 5.

  Therefore, according to the sixth example, the conveyance surface 82a that contacts the sheet S of the conveyance belt 82 protrudes from the vertical conveyance guide surface 72a of the outer guide member 72 by the protrusion amount d toward the outside of the sheet conveyance path. The sheet conveying performance equivalent to that of the wide belt can be achieved though the narrow conveying belt 82 is low in cost compared to the wide conveying belt 82 of the sheet conveying device 5. 5C can be realized and provided.

  Although the description will be omitted, as shown in FIGS. 16A and 16B, the configuration of the main body side of the paper feeding device 3 is the second transport path B as shown in FIG. 6 to 9 and so on, the hinge fulcrum shaft 76 provided at the lower part of the apparatus main body 78 is used as a swing fulcrum for the apparatus main body 78 provided with the housing 80 and the like. A configuration is adopted in which the open / close guide 79 is openable and closable in the directions of arrows C and D in FIG. With such an open / close configuration, the jammed paper (jam paper) is removed.

Next, with reference to FIG. 17A and FIG. 18A, a problem (problem) to be further improved according to the above-described prior application invention will be described using a sixth example. Hereinafter, in order to simplify the drawings and the description in the later-described embodiments and modified examples, or in the drawings to be described later, the conveyance guide rib 72b is not shown except in the case where the conveyance guide rib 72b is clearly shown, and replaced with this. The vertical conveyance guide surface (second outline guide surface) 72a of the outline guide member (second outline guide member) 72 will be described.
As shown in both figures, the leading end or leading end portion of the sheet S (sheet) conveyed by the first conveying means abuts on the belt conveying surface 82a while being appropriately guided by the outer guiding surface 71a of the outer guiding member 71. By elastically deforming the transport surface 82a in the paper entry direction (right side in the figure), the second transport means can grip and hold a relatively stiff paper (typically thick paper) S such as a thick paper in particular. It can be conveyed to the nip portion.

However, since the belt conveyance surface 82a is elastically deformed in the direction in which the paper S enters, the belt conveyance surface 82a has to protrude from the vertical conveyance guide surface 72a of the outer guide member 72 to the outside (center side of the second conveyance path B) by a predetermined amount d. The leading edge or leading edge of the cardboard S conveyed from the first conveying means collides with the vertical conveying guide surface 72a and cannot be gripped / held, or the gripping force is reduced.
On the other hand, when the belt conveyance surface 82a is protruded from the vertical conveyance guide surface 72a, the above problem is solved. However, the sheet S conveyed from the lower sheet feeder (see the lowermost sheet conveyance device 5 'in FIG. 19). The leading edge of the paper collides with the surface portion of the conveyor belt 82 held by the pulley 84, and this may become a so-called convex load, causing the leading edge of the paper S to buckle and deform and jam. At this time, if the linear velocity of the conveying belt 82 is extremely high, the convex load is reduced by making the linear velocity of the paper S conveyed from the lower sheet feeding unit equal to that of the conveying belt 82. However, it is not easy to carry out such transport control. The convex load means, for example, a phenomenon in which the sheet S conveyed from the lower sheet feeding unit slips in a direction returning to the upstream side, thereby causing a buckling / deformed jam or the like.

Therefore, the problems and problems to be solved by the present invention are as described above, and the second sheet conveyance path passes through the second sheet conveyance path from the lower sheet feed stage, regardless of the rigidity of the sheet from thick paper to thin paper. The sheet conveyed in this way is prevented from colliding with the belt and buckling / jamming, and the sheet conveyed from the first conveying means via the first sheet conveying path is transferred to the conveying surface of the belt. A sheet conveying apparatus (sheet conveying apparatus) that can realize and provide a sheet conveying apparatus that can be securely gripped and held, an image reading apparatus including the sheet conveying apparatus, a sheet conveying apparatus (sheet conveying apparatus), and / or an image reading apparatus. The main object is to realize and provide an image forming apparatus including the apparatus.
Hereinafter, embodiments and modifications for solving the above-described problems and problems and achieving the above-described object will be described in detail.

(First embodiment)
A first embodiment of the present invention will be described with reference to FIGS. The first embodiment shown in FIGS. 17 (b), 18 (b), 19 and 20 is the sixth example shown in FIGS. 14, 15, 17 (a) and 18 (a). The main difference is that a sheet conveying apparatus 5D is used instead of the sheet conveying apparatus 5C.
Further, the first embodiment will be described with reference to FIG. 1. Compared with the copying machine 1 provided with the paper conveyance device 5C of the sixth example provided in place of the paper conveyance device 5 shown in FIG. Then, as shown in FIG. 19, the sheet conveying apparatus 5D according to the first embodiment is provided in the middle stage of the sheet feeding apparatus 3, and the lower stage is provided with the conventional sheet conveying apparatus 5 ′ similar to the upper stage, and the middle stage The sheet transport device 5D and the lower sheet transport device 5 'are also different from each other in that the copier 1 includes the paper feed device 3 communicated with the second transport path B (vertical transport path).

  The sheet conveying apparatus 5D according to the first embodiment is different from the sheet conveying apparatus 5C of the sixth example shown in FIGS. 14, 15, 17A, and 18A in FIG. b), as shown in FIG. 18B, FIG. 19 and FIG. 20, the outer peripheral surface of the pulley 84 is connected to the second transport path B from the center of the reverse roller drive shaft 62a provided on the outer periphery of the first transport means 6. Is disposed within a range of a distance L2 from the downstream side (upward in the drawing) to the upstream side (downward in the drawing) of the second conveyance path B from the downstream end 71b of the outer guide surface 71a, and the belt conveyance means 8A. Is arranged such that the belt conveyance surface 82a protrudes outward (center side of the second conveyance path B) from the vertical conveyance guide surface 72a, and the protruding amount of the belt conveyance surface 82a from the vertical conveyance guide surface 72a d is the downstream end 7 of the outer guide surface 71a. The point that b is a boundary and the conveying surface 82a located on the downstream side of the second conveying path B is arranged to be larger than the conveying surface 82a located on the upstream side of the second conveying path B, The pulley 84 and the pulley 84 are different from each other in that the outer circumferential surface thereof is disposed on the inner side of the vertical conveyance guide surface 72a so as not to protrude outward from the vertical conveyance guide surface 72a (see FIG. 20) (first difference). ).

Further, the sheet conveying apparatus 5D according to the first embodiment is compared with the sheet conveying apparatus 5C of the sixth example, as shown in FIGS. 17B, 18B, 19, and 20. The belt conveying means 8A is arranged and clarified such that the belt conveying surface 82a is positioned outside the longitudinal conveying guide surface 72a at least downstream of the downstream end 71b of the outer guide surface 71a on the downstream side of the second conveying path B. The points are different (second difference).
Further, the sheet conveying apparatus 5D according to the first embodiment is compared with the sheet conveying apparatus 5C of the sixth example as shown in FIGS. 17B, 18B, 19 and 20. The belt conveying means 8A is different in that it is arranged and clarified so that the leading edge of the sheet S passing through the second conveying path B enters and contacts the belt conveying surface 82a with an acute entry angle θ. (Third difference).
17 and 18, the opening interval of the second conveyance path B and the thickness of the paper S are exaggerated and enlarged. In both figures, L1 indicates the distance and range from the downstream end 71b of the outer guide surface 71a to the center of the nip portion of the pulley 83 facing the grip roller 81 via the conveyor belt 82.

  According to the first embodiment, due to the first difference in which the belt conveying means 8A is arranged as described above, as shown in FIG. 18B, especially the thick paper conveyed from the first conveying means 6 or the like. When the leading edge of the relatively rigid sheet S bites into the belt conveying surface 82a and is elastically deformed, the belt conveying surface 82a is projected by a predetermined amount d so that the leading edge of the sheet S does not collide with the longitudinal conveying guide surface 72a. Is projected outward from the vertical conveyance guide surface 72a and the material of the conveyance belt 82 is selected, so that the paper S can be conveyed stably, and the leading edge of the paper S collides with the vertical conveyance guide surface 82a. The abnormal noise which generate | occur | produces can be prevented. Further, as shown in FIG. 17B, the leading edge of the sheet S conveyed from the upstream side of the second conveying path B (see the sheet conveying apparatus 5 ′ in FIG. 19) is held by a pulley 84 and is vertically It is also possible to prevent collision with the belt conveyance surface 82a protruding from the conveyance guide surface 82a.

Due to the second difference in which the belt conveying means 8A is arranged and clarified as described above, the leading edge of the sheet S having a relatively high rigidity such as thick paper conveyed from the first conveying means 6 bites into the belt conveying surface 82a. When elastically deformed, the leading edge of the paper S can be reliably prevented from colliding with the vertical conveyance guide surface 72a.
Further, due to the second difference in which the belt conveying means 8A is arranged and defined as described above, the leading edge of the sheet S conveyed from the upstream side of the second conveying path B (see the sheet conveying device 5 ′ in FIG. 19). Can be reliably guided to the nip portion of the second conveying means 7.
Furthermore, according to the first embodiment, it is needless to say that by providing the belt conveying means 8A and the like, the effects specific to the respective examples according to the above-mentioned prior application invention can be obtained.

  The belt conveying means 8 shown in parentheses together with the belt conveying means 8A of FIGS. 17 to 20 is shown in FIGS. 6 to 9 having both the first conveying path A, the second conveying path B, and the merging conveying path. In the second example, the belt conveying means 8 of the third example shown in FIG. 9, the present invention can be applied by arranging the arrangement in the same manner as described in the first embodiment. It is shown that. Also, in the belt conveying means 8A of the fourth example shown in FIGS. 10 to 12 and the fifth example shown in FIG. 13, the arrangement state is arranged in the same manner as described in the first embodiment. Therefore, it is needless to say that the present invention can be applied. The same applies to the embodiments and modified examples described later.

(Second Embodiment)
In the paper conveyance device 5D of the first embodiment shown in FIGS. 17B, 18B, 19 and 20, the protrusion amount of the upper pulley 83 from the vertical conveyance guide surface 72a is set to be lower. By taking a larger amount than the protruding amount of the pulley 84 on the side, buckling due to collision is prevented when the leading edge of the sheet S conveyed from the upstream side of the second conveying path B contacts the belt conveying surface 82a. It was possible to achieve. In addition, since the elastic deformation of the conveyance belt 82 is reduced when it collides with the surface of the surrounding conveyance belt 82 held by the pulley 84, more preferably, the pulley 84 is moved from the vertical conveyance guide surface 72a of the outer guide member 72. By disposing the inner side, the leading edge of the sheet S can be brought into contact with and collided with the conveyance surface 82a other than the surface of the conveyance belt 82 wound around the pulley 84, and buckling can be avoided.
In this case, as shown in FIGS. 17B and 18B, when the leading edge of the paper S guided and conveyed via the outer guide member 71 collides with the belt conveying surface 82a, the belt is conveyed. Since the surface 82a is elastically deformed toward the outer guide member 72, the distance 82 between the downstream end 71b of the outer guide surface 71a and the nip portion of the pulley 83 is more predetermined than the longitudinal conveyance guide surface 72a of the outer guide member 72. The amount of protrusion d is such that it protrudes by the amount d (to the extent that the leading edge of the paper S does not collide with the vertical conveyance guide surface 72a).

When the belt conveying means 8A is arranged as shown in FIGS. 17B and 18B, if the inclination of the conveying belt 82 with respect to the vertical conveying guide surface 72a is tight, the vicinity of the downstream end 71b of the outer guide surface 71a The protrusion amount d of the belt conveyance surface 82a with respect to the vertical conveyance guide surface 72a becomes small, and the rush angle θ2 with respect to the belt conveyance surface 82a of the leading edge of the sheet S conveyed from the first conveyance means 6 is shown in FIG. There is a possibility that the rush angle θ1 of the sixth example shown in a) is a right angle or an obtuse angle (θ2> θ1). As a result, although there is no problem with thick paper (paper having a metric basis weight of 256 g / m ² or more), the state shown in FIG. 18B is used for plain paper and paper with relatively low rigidity such as thin paper. If the leading edge of the sheet S hits the belt conveying surface 82a, the leading edge of the sheet may be bent, or the rush load may increase and slip in the conveying path, resulting in a stagnant jam. Transportability will be deteriorated. Further, in order to tighten the inclination of the conveying belt 82, the protrusion amount d of the belt conveying surface 82a from the vertical conveying guide surface 72a can be set unless the opening interval between the outer guide surface 71c and the vertical conveying guide surface 72a is widened. It becomes difficult to ensure, and the apparatus becomes large.
Therefore, the second embodiment shown in FIG. 21 has been created in order to solve the above-described problems.

  As shown in FIG. 21, the paper transport device 5E of the second embodiment is mainly different from the paper transport device 5D of the first embodiment in having the following configuration. That is, each of the belt conveying means 8C is provided with a conveying belt 82 that conveys the sheet toward the nip portion of the second conveying means, and three or more (three in this embodiment) are intermittently arranged in the sheet width direction Y. , 8C, 8D, and the conveyor belt 82 of the belt conveyor means 8D disposed at the center in the paper width direction Y among the three belt conveyor means 8C, 8C, 8D includes other belt conveyor means 8C, 8C is formed in the second conveyance path B direction with respect to the conveyance belt 82, and the protrusion amount of the outer peripheral surface of the pulley 84 from the vertical conveyance guide surface 82a in the other belt conveyance means 8C, 8C and the other belt conveyance means 8C. , 8C and the protruding amount of the belt conveying surface 82a from the vertical conveying guide surface 82a in the central belt conveying means 8D arranged corresponding to the protruding position of the outer peripheral surface of the pulley 84 from the vertical conveying guide surface 82a. Three belt conveying unit 8C to be approximately the same, 8C, points of arranging the 8D differs mainly.

In the second embodiment, in order to solve the above-described problem, for example, in the conventional sixth example, the distance between the axes of the pulleys 83 and 84 in the three belt conveying means 8D is increased, and the conveying belt 82 is moved. It has been noted that the inclination of the belt conveyance surface 82a with respect to the vertical conveyance guide surface 72a can be reduced by the arrangement. This prevents buckling of the leading edge of the sheet S from the second conveying path B, and allows the leading edge or leading edge of the sheet S guided and conveyed from the second conveying path A via the outer guide surface 71a to be conventional. As in the first to sixth examples, it is possible to securely grip and hold.
However, if the distance between all the axes of the conveyor belt 82 provided intermittently in the paper width direction Y is too long, it is conceivable that the running / rotation of the conveyor belt 82 is not stable. Therefore, among the conveyor belts 82 that are intermittently provided in the paper width direction Y, the distance between the axes of the pulleys 83 and 84 is increased only for the conveyor belt 82 of the belt conveyor means 8D provided in the center. The conveyor belt 82 of the belt conveyor means 8C disposed at both ends is the same as the conventional first to sixth examples with the same inter-axis distance. At this time, the conveyance belt 82 of the belt conveyance means 8C at both ends has the same configuration as the conventional first to sixth examples (the amount of protrusion of the belt conveyance surface 82a with respect to the vertical conveyance guide surface 72a), and from the first conveyance path A. The sheet that is guided and conveyed via the outer guide surface 71a is securely gripped to reduce the rush load. The transport belt 82 of the central belt transport means 8D has a long inter-axis distance between the pulleys 83 and 84 as shown in the figure, and the pulley 84 is disposed so as to be inside the vertical transport guide surface 72a.

  Since the pulleys 84 of the belt conveying means 8C at both ends protrude from the vertical conveying guide surface 72a, the protruding amount of the central conveying belt 82 corresponding to the pulley 84 of the conveying belt 82 at both ends with respect to the vertical conveying guide surface 72a is It is preferable to use a belt conveyance surface 82a ′ indicated by a two-dot chain line so as to be the same as the protruding amount from the vertical conveyance guide surface 72a of the pulley 84 of the belt conveying means 8C at both ends or to protrude more than that. With this configuration, the leading edge of the sheet guided and conveyed from the first conveying path A via the outer guide surface 71a collides with the surface of the conveying belt 82 held by the pulleys 84 of the belt conveying means 8C at both ends. Instead, it collides with a so-called antinode (effective conveying surface) portion of the conveying belt 82 in the central belt conveying means 8D and is absorbed by its elastic deformation, so that it is possible to prevent buckling and jamming at the time of sheet collision. it can.

The pulley 84 of the belt conveying means 8C at both ends and the pulley 84 of the central belt conveying means 8D have the same diameter including the pulley shaft 84a. As a result, the pulley 84 of the central belt conveying means 8D can share parts with those of the belt conveying means 8C at both ends. In this case, the central position of the pulley 84 of the central belt conveyance means 8D does not protrude toward the central side of the second conveyance path B with respect to the vertical conveyance guide surface 72a than the central position of the pulley 84 of the belt conveyance means 8C at both ends. It will be placed inside.
The inclination of the conveying belt 82 of the central belt conveying means 8D is the same as the inclination of the conveying belt 82 of the belt conveying means 8C at both ends, and the central belt conveying means on the inclined extension line of the conveying belt 82 of the belt conveying means 8C at both ends. The 8D conveying belt 82 is arranged so that the outer peripheral surface of the pulley 84 is positioned.
The conveying belt 82 of the belt conveying means 8C at both ends and the conveying belt 82 of the central belt conveying means 8D support the pulley shafts 83a by urging means (not shown) (see, for example, a compression spring 91 shown in FIG. 25, etc.). The outer guide member 72 is biased in a direction in which it is pressed against the grip roller 81 (not shown in FIG. 21) via a bearing member (not shown) (see, for example, a spring receiving portion 90 shown in FIG. 25 and the like). In contrast, the position shown in FIG. 21 is held.
Needless to say, in the second embodiment, the belt conveying means 8C, 8D and the like provide the specific effects of the examples according to the prior invention.

(Third embodiment)
A third embodiment of the present invention will be described with reference to FIGS.
The third embodiment shown in FIGS. 22 to 27 is different from the paper conveying device 5D of the first embodiment shown in FIGS. 17B, 18B, 19 and 20 in the paper. The only difference is that a sheet conveying device 5F is used instead of the conveying device 5D. The configuration of the third embodiment other than the differences is the same as that of the copier 1 shown in FIG. 19 of the first embodiment.

  The sheet conveying device 5F according to the third embodiment is different from the sheet conveying device 5D according to the first embodiment shown in FIGS. 17B, 18B, 19 and 20 in FIGS. As shown in FIG. 24, the rush angle variable for displacing the belt transport means 8A in a direction to change the rush angle of the leading edge of the paper S with respect to the belt transport surface 82a of the leading edge of the paper S transported by the first transport means 6. The point which has the means 99 and the point which has the control means 43 which controls the rush angle variable means 99 differ mainly.

The rush angle varying means 99 includes a link member 95 having a substantially L shape for connecting the pulley shafts 83a and 84a of the belt conveying means 8A, and one end portion thereof loosely connected to one end portion of the link member 95 via a pin 96. The connecting member 97 and a solenoid 98 as a driving means loosely connected to the other end of the connecting member 97 via a pin 96 are mainly configured.
Here, the initial position (hereinafter also referred to as “home position”) is the belt described in detail with reference to FIGS. 17B, 18B, 19 and 20 in the first embodiment. It means the arrangement state of the conveying means 8A (position state of the pulley 84, the conveying belt 82, etc.), that is, the position shown in the figure. As shown in FIG. 22, in the case where the belt conveying means 8A occupies the home position, the leading end portion of the paper S conveyed by the first conveying means 6 (indicated by a two-dot chain line in the figure) is virtually The entry angle at this time is defined as θ1.

The link member 95 has a bearing portion that rotatably supports the pulley shafts 83a and 84a at a predetermined distance shown in the drawing. A support member (not shown) having a bearing portion that rotatably supports the pulley shafts 83a and 84a at a predetermined distance shown in the drawing is also provided on the back side of the paper surface, whereby the pulley shafts 83a and 84a are illustrated. It is supported so as to be rotatable with a predetermined distance between axes. The link member 95 and the connecting member 97 constitute a link device. The pulley shaft 83a is supported by a stationary member of the opening / closing guide 79 so as to be rotatable within a range of a predetermined angle, that is, rotatably within the swing range of the belt conveying means 8A, but the pulley shaft 84a side swings. Therefore, the opening / closing guide 79 is free.
If it is desired to further reduce the rotational load when the conveying belt 82 is driven to rotate by the grip roller 81, instead of the pulley shafts 83a and 84a, the pulley shafts that rotatably support the pulleys 83 and 84 are provided. A configuration may be used (see belt conveying means 8B shown in FIG. 28 and the like described later).

As shown in FIG. 25 and the like, similarly to the first and second embodiments, a compression spring 91 is mounted between the spring receiving portion 90 that supports the pulley shaft 83a and the stationary member on the opening / closing guide 79 main body side. The outer peripheral surface of the conveying belt 82 (belt conveying surface 82a) is in contact with the outer peripheral surface of the grip roller 81 with a predetermined pressure by the urging force of the compression spring 91, thereby forming a nip portion.
When the belt conveying means 8A occupies the home position, it may be held at that position by its own weight. However, since it is assumed that the belt conveying means 8A moves due to external vibration or the like, for example, a magnet It is preferable to hold at the home position by a catcher or urging means (not shown). As an urging means (not shown), for example, a compression spring mounted on the outer peripheral portion of the plunger 98a which is reciprocally movable by the solenoid 98 can be cited. In this case, the biasing force of the compression spring urges the plunger 98a to extend, that is, the belt conveying means 8A is always urged through the link device in the direction occupying the home position shown in FIG. The biasing means is not limited to a compression spring, and is, for example, stretched between a lower end side in the drawing of the link member 95 and a pin (not shown) planted on the stationary member of the opening / closing guide 79, and the belt conveying means 8A is connected to the home A tension spring or the like that biases in the direction that occupies the position may be used. This is the same in modified examples 2, 3, 4 and the like described later. In the following description, it is assumed that a compression spring (not shown) is attached.

The solenoid 98 is formed of, for example, a pull-type DC solenoid, and is fixed to a stationary member of the open / close guide 79. When power is supplied to the solenoid 98 and the solenoid 98 is turned on, as shown in FIGS. 22 to 23, the belt conveying means 8A that has occupied the home position against the biasing force of a compression spring (not shown) , And oscillates and displaces clockwise about the pulley shaft 83a to a predetermined position (hereinafter referred to as “oscillation position”) so as to occupy an entry angle θ2 smaller than the entry angle θ1 of the home position. A stopper member that restricts the swing range of the belt transport unit 8A may be provided so that the belt transport unit 8A does not swing further clockwise than the swing position.
As described above, the belt conveyance unit 8A allows conveyance of the sheet from the second conveyance path B and swings at a home position shown in FIG. 22 and a rush angle θ2 smaller than the rush angle θ1 at the home position. It is configured to be displaceable between positions (θ1> θ2).

The configuration related to the control around the sheet conveying device 5F of the present embodiment will be briefly described with reference to FIG. A sheet detection sensor 39 as a sheet detection unit that detects the leading edge of the sheet is disposed below the inner guide member 70 in a state that does not interfere with sheet conveyance. The paper detection sensor 39 is composed of a reflective photosensor. The uppermost sheet S is fed out by the point that the sheet conveyance distance from the contact position of the outer peripheral surface of the pickup roller 60 with the uppermost sheet S to the arrangement position of the sheet detection sensor 39 is constant and the rotation of the pickup roller 60 starts. The linear velocity (linear velocity) of the paper is calculated by the CPU 44 using a timer provided in the control means 43 from the time taken to reach the paper detection sensor 39 via the rotational drive of the first conveying means 6. By calculating, it is possible to know the time for the leading edge of the paper S to reach the nip portion of the second conveying means 7 and the like. Note that. A reflection type photo sensor or a transmission type photo sensor for detecting that the leading edge of the sheet S starts to be nipped by the nip portion of the second conveying means 7 can be provided in the vicinity of the nip portion without being calculated by the CPU 44. I do not care. Further, the sheet linear velocity detecting means for detecting the linear velocity of the sheet is not limited to the sheet detecting sensor 39, and the sheet detecting sensor 39 and a sheet detecting means for detecting the leading edge of the sheet S shown in FIG. A paper sensor 88 may be used in combination.
As shown in FIGS. 22 and 23, the stationary member of the open / close guide 79 is provided with a home position sensor 40 including a limit switch for detecting the home position of the belt conveying means 8A. The home position sensor 40 is not limited to a limit switch, and may be, for example, a light shielding plate protruding from a link member, a transmission type photo sensor that is selectively engaged with the light shielding plate at the home position of the belt conveying means 8A, or the like.

  In FIG. 24, the control means 43 is for mainly performing on / off control of the solenoid 98 of the rush angle varying means 99 of the paper transport device 5F, control of the number of driving pulses supplied to the paper feed motor, and the like. Hereinafter, for the sake of simplicity, main control means (main control device) (not shown) is assumed to control the overall operation of the copying machine 1 except for the control of the paper transport device 5F of the paper feeding device 3 shown in FIG. The main control device and the control means (control device) 43 will be described as transmitting and receiving a command signal, an on / off signal, a data signal, and the like. The main control unit and the control unit 43 are provided, for example, on a control board (not shown) on the image forming apparatus main body 2 side shown in FIG. When the paper feeding device 3 is a unit of movement as a product form, the control unit 43 may be provided on the main body side of the paper feeding device 3.

The control means 43 includes a CPU (central processing unit) 44, an I / O (input / output) port (not shown), a ROM (read only storage device) 45, a RAM (read / write storage device) 46, a timer (not shown), and the like. And a microcomputer having a configuration in which they are connected by a signal bus.
The CPU 44 receives the start switch and various keys (not shown) of the operation panel 48 as an operation unit having the operation screen unit of the touch panel system, the sheet detection sensor 39, and the like via the input port and each sensor input circuit. The home position sensor 40 is electrically connected.

  On the operation panel 48, as various keys, a numeric keypad (not shown) for setting and setting the number of sheets S to be fed and the like, and a paper feed stage (for storing relatively high rigidity paper such as cardboard) A high-rigidity paper (high-rigidity sheet) selection key or its paper feed stage selection key for generating a signal for selecting and setting the paper feed tray 51 and the paper conveyance device 5F) and feeding and conveying the paper S, and a thick paper A signal for selecting and setting a paper feed stage (paper feed tray 51 and paper transport device) in which paper with relatively low rigidity such as plain paper and thin paper other than the paper is stored and driving the paper S to be fed and transported A plain paper selection key, a thin paper selection key, or a paper feed stage selection key thereof are provided.

The CPU 44 has a calculation function for obtaining the sheet linear velocity by calculation based on an output signal (data signal) from the sheet detection sensor 39. Further, the CPU 44 sets the time when the leading edge of the sheet S starts to be nipped and conveyed by the nip portion of the second conveying means 7 from the position where the leading edge of the sheet starts to rotate the pickup roller 60 (starts rotation driving of the sheet feeding motor 23). 2 It also has a calculation function for calculating from a predetermined transport distance of the preset paper S reaching the nip portion of the transport means 7 and the calculated linear speed of the paper.
The CPU 44 is electrically connected to the paper feed motor 23 via the output port and a stepping motor drive circuit (not shown), and to a solenoid 98 via a solenoid drive circuit (not shown), and a command signal for driving and controlling them. Are transmitted to the motor drive circuit and the solenoid drive circuit, respectively.

  The RAM 46 inputs / outputs these signals by temporarily storing the calculation results of the CPU 44 or storing the output signals from the high-rigidity paper selection key of the operation panel 48 and the paper detection sensor 39 as needed. The ROM 45 stores in advance an “operation program”, “relationship data on the number of pulses supplied to the paper feed motor 23 via a motor drive circuit (not shown)” and the like for the CPU 44 to perform a control function described later. . The timer has a function as time measuring means for measuring time.

When the sheet is conveyed from the second conveyance path B, the CPU 44 detects, for example, that the sheet is conveyed from the lowermost sheet conveying apparatus 5 ′ in FIG. Based on an output signal from a paper detection sensor (not shown) and an output signal from the home position sensor 40 disposed in the belt, the displacement of the belt conveying means 8A is prohibited, and the belt conveying means 8A occupies the home position. It has a first function of controlling the solenoid 98 of the entry angle varying means 99 to be turned off.
Based on output signals from the timer, the paper detection sensor 39 and the home position sensor 40 (not shown), the CPU 44 has at least the leading edge of the paper conveyed from the first conveying means 6 via the first conveying path A. Before contacting the belt conveyance surface 82a, that is, at the same time when the sheet feeding motor 23 starts to rotate, the belt conveyance means 8A is displaced in a direction in which the entry angle becomes smaller, and the entry is made to occupy the swing position. It has a second function of performing on-drive control of the solenoid 98 of the angle varying means 99.

Based on output signals from the timer, the paper detection sensor 39 and the home position sensor 40 (not shown), the CPU 44 determines that the leading edge of the paper conveyed from the first conveying means 6 via the first conveying path A is the first. Immediately after being pinched by the nip portion of the second conveying means 7, it has a third function of controlling the solenoid 98 of the rush angle varying means 99 to turn off so that the belt conveying means 8A returns to the home position.
Based on output signals from the timer (not shown), the paper detection sensor 39 and the home position sensor 40, the CPU 44 has at least the trailing edge of the paper conveyed from the first conveying means 6 via the first conveying path A. Before passing through the downstream end 71b of the outer guide member 71 as a guiding means other than the conveying belt 82, the belt conveying means 8A is displaced in a direction in which the rushing angle becomes smaller, and enters the swing position. It has a fourth function for controlling the solenoid 98 of the angle varying means 99 to be turned on.

Based on the above configuration, the operation of the main part will be described.
First, for example, a description will be given of a transport operation when the middle paper feed tray 51 and the paper transport device 5F are selected as predetermined paper feed stages in the paper feed device 3 shown in FIG. Start after the middle sheet feed tray 51 and the sheet transport device 5F are selected by the operation of the sheet feed stage selection key (not shown) or the high rigidity sheet selection key (not shown) on the operation panel 48 and the copy conditions are selected and set by various key operations. When the switch is turned on, the paper feeding operation is started. When the solenoid 98 is turned on simultaneously with the start of the sheet feeding operation, the plunger 98a and the connecting member 97 are pulled down in the direction of the arrow in FIG. 22, and the link member 95 swings in the direction of the arrow (clockwise) in FIG. Due to the dynamic displacement, the belt conveying means 8A held at the home position shown in FIG. 22 is oscillated and displaced in the direction of the arrow (clockwise) in FIG. 22, and then the entry angle θ2 smaller than the entry angle θ1 of the home position. It occupies the swing position shown in FIG.

  Next, the feeding operation is started. That is, after separation of the sheets S one by one by the same sheet feeding and separating mechanism as in the first and second examples described above, one sheet S is further conveyed downstream of the first conveyance path A, When the leading edge or leading edge of the sheet S abuts against the belt conveying surface 82a with a small rushing angle θ2, the rush load on the belt conveying surface 82a of the leading edge or leading edge of the sheet S is the first and second examples described above. It will be more reduced than. Further, since the conveyance belt 82 travels so that the sheet S advances in the diagonally upper right direction indicated by the arrow a in FIGS. 23 and 25, the sheet S after contacting the belt conveyance surface 82a. As shown in FIG. 25, the sheet S is conveyed in a state where the contact area of the sheet S with respect to the belt conveyance surface 82a is increased as compared with the first and second examples described above, and the sheet S is also conveyed in the first conveyance. In a state where the conveyance resistance received from the outer guide surface 71a of the outer guide member 71 constituting the path A and the inner guide surface 70a of the inner guide member 70 is reduced as compared with the first and second examples described above, the grip The pair of rollers 81 and the conveyor belt 82 is nipped and conveyed downstream in the substantially vertical upward direction. At this time, as described above, the sheet S is subjected to the conveyance propulsion force that is transmitted from the conveyance belt 82 in the conveyance direction, and is directed toward the nip portion between the grip roller 81 and the conveyance belt 82 by the conveyance belt 82. Therefore, even with a highly rigid paper S, feeding and transport operations can be performed in a more stable state without causing a transport failure.

  When the leading edge of the sheet S begins to be clamped at the nip portion between the grip roller 81 and the conveying belt 82, the solenoid 98 is turned off, so that the belt conveying means 8A is driven by its own weight and the urging force of a compression spring (not shown). The home position shown in FIG. This is because a sufficient conveyance force acts on the paper S from the grip roller 81 and the conveyance belt 82, so that the high-rigidity paper S can be smoothly conveyed, so that the energization time to the solenoid 98 can be shortened. And energy saving of the device can be achieved.

  As shown in FIG. 26, the sheet S is nipped and conveyed at the nip portion between the grip roller 81 and the conveying belt 82 and further conveyed downstream, but the rear end of the sheet S is the outer guide surface of the outer guide member 71. After being transported along 71a, the solenoid 98 is turned on again at least immediately before the downstream end 71b of the outer guide surface 71a is released, and is held at the home position shown in FIG. 26 by the same detailed operation as described above. The belt conveying means 8A which has been moved is oscillated and displaced in the direction of the arrow (clockwise) in the figure, and again occupies the oscillating position shown in FIG.

  In the case of a stiff sheet such as thick paper, the outer guide surface 71a is separated and the rear end of the sheet S is other than the transport belt 82 such as the belt transport surface 82a and the vertical transport guide surface 72a of the outer guide member 72. The trailing edge noise at the time of contact with the configured guide means becomes a problem, but the rear end of the paper S contacts the paper S before the outer guide surface 71a of the outer guide member 71 is detached. By doing so, the impact when the trailing edge of the paper S comes into contact with the transport belt 82 is alleviated, the contact force is reduced, and the contact of the outer guide member 72 with the vertical transport guide surface 72a is also reduced. It becomes.

  Next, for example, in the paper feeding device 3 shown in FIG. 19, a transport operation when the lowermost paper feed tray 51 and the paper transport device 5 'are selected as the predetermined paper feed stages will be described. The lowermost paper feed tray 51 and the paper transport device 5 'are selected by operation of a paper feed stage selection key or plain paper selection key or thin paper selection key (not shown) on the operation panel 48, and copy conditions are selected and set by various key operations. Thereafter, when the start switch is turned on, the sheet feeding operation from the lowermost sheet feeding tray 51 and the sheet conveying device 5 ′ is performed as in the conventional case. At this time, the solenoid 98 is kept off simultaneously with the start of the sheet feeding operation from the sheet conveying device 5 ', and the belt conveying means 8A remains held at the home position shown in FIG.

Therefore, according to the third embodiment, the leading edge of the sheet with respect to the conveyance surface 82a of the conveyance belt 82 is obtained from the fact that the belt conveyance means 8A has the characteristic effects of the examples according to the invention of the prior application described above. Since the rushing angle θ of the belt can be changed, specifically, the piercing angle variable means 99 for displacing the belt conveying means 8A in the direction of changing the rushing angle θ is provided. Since the belt conveying means 8A is displaced at least before the leading edge of the sheet conveyed via the conveying path A comes into contact with the belt conveying surface 82a, the rush angle is decreased. The conveyance resistance received from the outer guide surface 71a and the inner guide surface 70a constituting the conveyance path A can be reduced as compared with the first and second examples described above, and the sheet S By further reducing the rush load on the belt conveyance surface 82a at the leading edge or the leading edge of the belt, the conveyance / rush load resistance can be further reduced as compared with the first and second examples described above, and a more stable feeding operation can be achieved. Is possible.
Further, the trailing edge of the sheet S nipped and conveyed at the nip portion of the second conveying means 7 passes through the first conveying means 6 and is disposed downstream of the first conveying means 6 and upstream of the second conveying means 7. Immediately before the outer guide surface 71a of the outer guide member 71 which is a guide means other than the belt conveying means 8A is released, the solenoid 98 which is the driving means and driving source of the rush angle varying means 99 is turned on to drive the conveying belt 82. By contacting the paper S, the impact when the trailing edge of the paper S contacts the transport belt 82 is reduced, the contact force is reduced, and the outer guide member 72 is brought into contact with the vertical transport guide surface 72a. As a result, the trailing edge splash sound of the paper S can be reduced.

(Modification 1 of 3rd Embodiment)
With reference to FIGS. 28-30, the modification 1 of 3rd Embodiment is demonstrated.
The modified example 1 shown in FIG. 28 to FIG. 30 uses only a paper transport device 5G instead of the paper transport device 5F, as compared with the paper transport device 5F of the third embodiment shown in FIGS. Is different. The configuration of the modification 1 other than the differences is the same as that of the copier 1 shown in FIG. 19 of the first to third embodiments.

  The sheet conveying apparatus 5G of the first modification is replaced with the belt conveying means 8A as shown in FIGS. 28 to 30 as compared with the sheet conveying apparatus 5F of the third embodiment shown in FIGS. Instead of using the belt conveying means 8B and the rush angle varying means 99, the direction in which the rush angle of the leading edge of the sheet S with respect to the belt conveying surface 82a of the leading edge of the sheet S conveyed by the first conveying means 6 is changed. The difference is mainly that the rush angle varying means 109 for displacing the belt conveying means 8B is used, and that the control means 43A for controlling the rush angle varying means 109 is used in place of the control means 43.

  Compared to the belt conveying means 8A, the belt conveying means 8B has, for example, a point that three pulleys 83 are rotatably supported around a pulley shaft 83b made of steel, for example, around a pulley shaft 84b made of steel. The point that the three pulleys 84 are rotatably supported and the connecting member 110 that integrally connects the pulley shaft 83b and the pulley shaft 84b is provided on the front side and the back side of the paper surface in FIG. Mainly different. The conveyor belt 82 is wound around pulleys 83 and 84 that are rotatably supported by the pulley shafts 83b and 84b so as to be able to run and rotate. In order to reduce the rotational resistance load of the pulleys 83 and 84 with respect to the pulley shafts 83b and 83b, the pulleys 83 and 84 are preferably made of, for example, polyacetal resin that is lightweight and has good durability and lubrication performance. The contact surfaces of the pulleys 83 and 84 with the conveyor belt 82 are appropriately subjected to surface treatment so as to have an appropriate coefficient of friction with respect to the rubber conveyor belt 82.

The rush angle changing means 109 includes a connecting member 110 that connects and fixes the pulley shafts 83b and 84b of the belt conveying means 8B, a timing belt pulley 112 that is fixed to the connecting member 110 around the pulley shaft 83b, and an output shaft. The timing belt pulley 111 is fixed and mainly includes a stepping motor 114 as a driving unit and a timing belt 113 stretched between the timing belt pulley 111 and the timing belt pulley 112.
The pulley shaft 83b is supported by the stationary member of the opening / closing guide 79 so as to be rotatable within a predetermined angle range, that is, rotatably within the swing range of the belt conveying means 8B, but the pulley shaft 84b side swings. Therefore, the opening / closing guide 79 is free. The pulley shaft 83b, the connecting member 110, the timing belt pulley 112, and the pulley shaft 84b are all integrated and fixed to the connecting member 110 as described above.
The initial position (home position) of the belt conveyance unit 8B in the first modification is the same arrangement state (position state of the pulley 84 and the conveyance belt 82) as the initial position of the belt conveyance unit 8A in the third embodiment, that is, This means the position shown in FIG. As shown in FIG. 28, in the case where the belt conveying means 8B occupies the home position, the leading end portion of the paper S conveyed by the first conveying means 6 (indicated by a two-dot chain line in the figure) is virtually The entry angle at this time is defined as θ1.

The connecting member 110 fixes the pulley shafts 83b and 84b with a predetermined inter-axis distance shown in the drawing, and is also provided on the back side of the paper surface. As shown in FIG. 25 and the like, a compression spring (not shown) is mounted between a spring receiving portion (not shown) that supports the pulley shaft 83b and a stationary member on the open / close guide 79 main body side. The outer peripheral surface of the conveying belt 82 (belt conveying surface 82a) is brought into contact with the outer peripheral surface of the grip roller 81 with a predetermined pressure by the urging force of the compression spring, thereby forming a nip portion.
In the state where the belt conveying means 8B occupies the home position, it may be held at that position by its own weight and the load of the stepping motor 114, but it is assumed that the belt conveying means 8B moves due to external vibration or the like. Therefore, it is preferable to hold it at the home position by, for example, a magnet catcher or urging means (not shown). As an urging means (not shown), for example, it is stretched between a lower end in the drawing of the connecting member 110 and a pin (not shown) planted on the stationary member of the open / close guide 79, and the belt conveying means 8B occupies the home position. It may be a tension spring that urges the spring. In the following description, it is assumed that a tension spring (not shown) is attached.

The stepping motor 114 is an example of a drive motor that is rotationally driven by pulse input, and is fixed to a stationary member on the housing 80 side. When a predetermined number of pulses are supplied to the stepping motor 114 and the stepping motor 114 is turned on, the timing belt pulley 111 moves in the direction of the arrow in FIG. 28 against the urging force of a tension spring (not shown) as shown in FIGS. It is rotated by a predetermined number of steps corresponding to a predetermined number of pulses in the (clockwise direction), and then the timing belt 113 and the timing belt pulley 112 are respectively rotated in the direction of the arrow (clockwise direction) in FIG. The rotational driving force is transmitted to the pulley shaft 83b and the connecting member 110, and the belt conveying means 8B occupying the home position has a predetermined position (occupying a rush angle θ2 smaller than the rush angle θ1 of the home position). (Hereinafter referred to as the “oscillation position”), the actuator is oscillated clockwise around the pulley shaft 83b. Displace.
As described above, the belt conveyance unit 8B allows conveyance of the sheet from the second conveyance path B and swings at the home position shown in FIG. 28 and the rush angle θ2 smaller than the rush angle θ1 at the home position. It is configured to be displaceable between positions (θ1> θ2).

With reference to FIG. 30 as well, the configuration related to the control around the sheet conveying device 5G of the present embodiment will be described focusing on the differences from the third embodiment. As in the third embodiment, the paper detection sensor 39 and the home position sensor 40 are respectively disposed at predetermined positions. Similar to the third embodiment, the leading edge of the sheet S is transported in the second direction by calculating the linear velocity of the sheet by the calculation of the CPU 44A using the timer provided in the sheet detection sensor 39 and the control unit 43A. The time to reach the nip portion of the means 7 can be known.
In FIG. 30, the control means 43A mainly controls the number of drive pulses supplied to the stepping motor 114 of the rush angle varying means 109 of the paper transport device 5G, and controls the number of drive pulses supplied to the paper feed motor. belongs to. Hereinafter, for the sake of simplicity, main control means (main control device) (not shown) is assumed to control the entire operation of the copying machine 1 except for control of the paper transport device 5G and the like of the paper feeding device 3 shown in FIG. The main control device and the control means (control device) 43A will be described as transmitting and receiving a command signal, an on / off signal, a data signal, and the like. The main control means and the control means 43A are provided, for example, on a control board (not shown) on the image forming apparatus main body 2 side shown in FIG.

  The control means 43A includes a CPU (central processing unit) 44A, an I / O (input / output) port (not shown), a ROM (read only storage device) 45A, a RAM (read / write storage device) 46, a timer (not shown), and the like. And a microcomputer having a configuration in which they are connected by a signal bus.

The CPU 44A is electrically connected to the start switch and various keys (not shown) of the operation panel 48, the paper detection sensor 39, and the home position sensor 40 through the input port and sensor input circuits.
Similar to the CPU 44 of the third embodiment, the CPU 44A calculates the calculation function for obtaining the sheet linear velocity and the time when the leading edge of the sheet S starts to be nipped and conveyed by the nip portion of the second conveying means 7. It also has a calculation function to calculate from the linear velocity. The CPU 44A is electrically connected to the paper feed motor 23 via the output port and a stepping motor drive circuit (not shown), and is electrically connected to the stepping motor 114 via a stepping motor drive circuit (not shown), and drives and controls them. A command signal is transmitted to each of the motor drive circuits.

  The RAM 46 inputs / outputs these signals by temporarily storing the calculation results of the CPU 44A, or storing the output signals from the high-rigidity paper selection key of the operation panel 48 and the paper detection sensor 39 as needed. The ROM 45A contains an “operation program”, “relationship data on the number of pulses supplied to the paper feeding motor 23 and the stepping motor 110 via a stepping motor drive circuit (not shown)” for the CPU 44A to perform a control function described later, and the like. Stored in advance. The timer has a function as time measuring means for measuring time.

When the sheet is conveyed from the second conveyance path B, the CPU 44A detects, for example, that the sheet is conveyed from the lowermost sheet conveying apparatus 5 ′ in FIG. 19, for example, the lowermost sheet conveying apparatus 5 ′. Based on an output signal from a paper detection sensor (not shown) and an output signal from the home position sensor 40 disposed in the belt, the displacement of the belt conveying means 8B is prohibited, and the belt conveying means 8B occupies the home position. The stepping motor 114 of the rush angle varying means 109 has a first function of performing off drive control (pulse supply is not performed).
Based on the output signals from the timer (not shown), the paper detection sensor 39 and the home position sensor 40, the CPU 44A has at least the leading edge of the paper conveyed from the first conveyance means 6 via the first conveyance path A. Before contacting the belt conveying surface 82a, that is, at the same time when the paper feeding motor 23 starts to rotate, the belt conveying means 8B is displaced in a direction in which the rushing angle becomes smaller, so that it occupies the swing position. The stepping motor 114 of the angle varying means 109 has a second function of performing on drive control (supplying a predetermined number of pulses for normal rotation).

Based on output signals from the timer, the sheet detection sensor 39 and the home position sensor 40 (not shown), the CPU 44A determines that the leading edge of the sheet conveyed from the first conveying means 6 via the first conveying path A is the first. (2) Immediately after being sandwiched between the nip portions of the transport means 7, the stepping motor 114 of the rush angle varying means 109 is turned on so that the belt transport means 8B returns to the home position (a predetermined number of pulses to be reversed is supplied). Has a third function.
Based on the output signals from the timer (not shown), the paper detection sensor 39 and the home position sensor 40, the CPU 44A has at least the trailing edge of the paper conveyed from the first conveying means 6 via the first conveying path A. Before passing through the downstream end 71b of the outer guide member 71 as the guiding means constituted by other than the conveying belt 82, the belt conveying means 8B is displaced in a direction in which the rushing angle becomes smaller, and enters the swing position. The stepping motor 114 of the angle varying means 109 has a fourth function of performing on-drive control (supplying a predetermined number of pulses for normal rotation).

Based on the above configuration, the operation of the main part will be described.
First, for example, a description will be given of a transport operation when the middle paper feed tray 51 and the paper transport device 5G are selected as predetermined paper feed stages in the paper feed device 3 shown in FIG. Starts when the middle paper feed tray 51 and the paper transport device 5G are selected by the operation of the paper feed stage selection key (not shown) or the high rigidity paper selection key (not shown) on the operation panel 48 and the copy conditions are selected and set by various key operations. When the switch is turned on, the paper feeding operation is started. When the predetermined number of pulses for forward rotation is supplied to the stepping motor 114 at the same time as the paper feeding operation is started and is turned on, the forward driving force of the stepping motor 114 is transmitted in the order described above, and the connecting member 110 is shown in FIG. 28, the belt conveying means 8B held at the home position shown in FIG. 28 is oscillated and displaced in the direction of the arrow (clockwise) in FIG. 28, and then the home position. The oscillating position shown in FIG. 29, where the rush angle θ2 is smaller than the rush angle θ1, is stopped and held.

  Next, a feeding operation similar to that in the third embodiment is started. That is, after separation of the sheets S one by one by the paper feed separation mechanism, one sheet S is further conveyed to the downstream side of the first conveyance path A, and the leading edge or leading edge of the sheet S is the belt conveying surface 82a. , The rush load on the belt conveyance surface 82a at the leading edge or the leading edge of the sheet S is further reduced than in the first and second examples described above. Furthermore, since the conveyance belt 82 travels so that the sheet S advances in the diagonally upward right direction indicated by the arrow a in FIG. 29, the sheet S after contacting the belt conveyance surface 82a includes a belt. The sheet S is conveyed in a state where the contact area of the sheet S with the conveyance surface 82a is increased as compared with the first and second examples described above, and the outer guide member 71 constituting the first conveyance path A is also conveyed. The pair of grip roller 81 and conveyor belt 82 is substantially used in a state where the conveyance resistance received from the outer guide surface 71a of the inner guide member 70 and the inner guide surface 70a of the inner guide member 70 is reduced as compared with the first and second examples. It is nipped and conveyed downstream in the vertically upward direction. At this time, as described above, the sheet S is subjected to the conveyance propulsion force that is transmitted from the conveyance belt 82 in the conveyance direction, and is directed toward the nip portion between the grip roller 81 and the conveyance belt 82 by the conveyance belt 82. Therefore, even with a highly rigid paper S, feeding and transport operations can be performed in a more stable state without causing a transport failure.

  When the leading edge of the sheet S begins to be clamped at the nip portion between the grip roller 81 and the conveyor belt 82, a predetermined number of pulses for reverse rotation is supplied to the stepping motor 114 and is turned on again. The belt conveying means 8B is returned to the home position shown in FIG. 28 by performing an operation opposite to the operation described above. This is because, as in the third embodiment, a sufficient conveyance force acts on the paper S from the grip roller 81 and the conveyance belt 82, so that the high-rigidity paper S can be smoothly conveyed.

  Also, in the first modification, as with reference to FIG. 26 of the third embodiment, the sheet S is nipped and conveyed at the nip portion between the grip roller 81 and the conveying belt 82 and further conveyed downstream, After the rear end of S is conveyed along the outer guide surface 71a of the outer guide member 71, the stepping motor 114 again performs a predetermined number of pulses for normal rotation at least immediately before leaving the downstream end 71b of the outer guide surface 71a. Is supplied and turned on, the belt conveying means 8B held at the home position shown in FIG. 28 is oscillated and displaced in the arrow (clockwise) direction in FIG. 28 by the same detailed operation as described above. It occupies the swing position shown in FIG. The reason and advantage are the same as the contents described in the third embodiment.

  Next, for example, in the paper feeding device 3 shown in FIG. 19, a transport operation when the lowermost paper feed tray 51 and the paper transport device 5 'are selected as the predetermined paper feed stages will be described. The lowermost paper feed tray 51 and the paper transport device 5 'are selected by operation of a paper feed stage selection key or plain paper selection key or thin paper selection key (not shown) on the operation panel 48, and copy conditions are selected and set by various key operations. Thereafter, when the start switch is turned on, the sheet feeding operation from the lowermost sheet feeding tray 51 and the sheet conveying device 5 ′ is performed in the same manner as in the conventional case. At this time, the stepping motor 114 remains off (no pulse is supplied) simultaneously with the start of the sheet feeding operation from the sheet conveying device 5 ′, and the belt conveying means 8B is held at the home position shown in FIG. It becomes.

Therefore, according to the first modification, the belt conveying means 8B has the characteristic effect of each example according to the above-mentioned prior application, and the leading edge of the sheet with respect to the conveying surface 82a of the conveying belt 82 can be obtained. By configuring the rush angle θ to be changeable, more specifically, by having the rush angle varying means 109 for displacing the belt transport means 8B in the direction of changing the rush angle θ, the first transport path is more than the first transport path 6. Since the belt conveying means 8B is displaced at least before the leading edge of the sheet conveyed via A contacts the belt conveying surface 82a, the first conveying path is displaced in a direction in which the entry angle is reduced. The conveyance resistance received from the outer guide surface 71a and the inner guide surface 70a constituting A can be reduced as compared with the first and second examples described above, and the leading edge of the paper S Since the rush load on the belt conveyance surface 82a at the end or the tip is further reduced than in the first and second examples described above, the conveyance / rush load resistance can be further reduced, and a more stable feeding operation can be performed. It becomes possible.
Further, the trailing edge of the sheet S nipped and conveyed at the nip portion of the second conveying means 7 passes through the first conveying means 6 and is disposed downstream of the first conveying means 6 and upstream of the second conveying means 7. Immediately before the outer guide surface 71a of the outer guide member 71, which is a guide means other than the belt conveying means 8B, is disengaged, the stepping motor 114, which is the driving means / drive source of the rush angle varying means 109, is turned on, and the conveying belt 82 is driven. Is brought into contact with the paper S, the impact when the trailing edge of the paper S comes into contact with the transport belt 82 is reduced, the contact force is reduced, and the outer guide member 72 is brought into contact with the vertical transport guide surface 72a. As a result, the trailing edge splash sound of the paper S can be reduced.

Further, since the stepping motor 114 is used as the driving means (driving source) of the belt angle varying means 119, the response time is faster than the solenoid 98 used in the third embodiment, and the motor rotation speed can be easily changed. In the paper-passing mode and image forming apparatus with a short paper interval time, it is possible to quickly change and change the rush angle of the belt conveyance means, so it is possible to cope with even devices with a short paper interval and paper-passing mode. It becomes. Further, with respect to the trailing edge noise countermeasure of the paper S described in the third embodiment, by reducing the rotation speed of the stepping motor 114, the change speed / switching speed in the direction in which the entry angle is reduced is slowed. Further, it is possible to alleviate the impact when the paper and the belt conveyance surface 82a come into contact with each other, further reduce the contact force / rush load (convex load), and improve the effect of the squeaking noise countermeasure.
Furthermore, by using the stepping motor 114, it is possible to perform feeding control by setting the change in the direction in which the entry angle is reduced in multiple stages according to the paper type.

(Modification 2 of 3rd Embodiment)
With reference to FIG. 31, the modification 2 of 3rd Embodiment is demonstrated.
Modification 2 shown in FIG. 31 is different from the paper conveyance device 5G of Modification 1 shown in FIGS. 28 to 30 only in that a paper conveyance device 5H instead of the paper conveyance device 5G is used. The configuration of the second modification other than the differences is the same as that of the copying machine 1 shown in FIG. 19 of the first to third embodiments.

  As shown in FIG. 31, the paper transport device 5H according to the second modification is replaced with the first transport as shown in FIG. 31 in comparison with the paper transport device 5G according to the first modification shown in FIGS. 28 to 30. FIG. 30 shows the use of a rush angle varying means 129 for displacing the belt conveying means 8B in a direction to change the rush angle of the leading edge of the sheet S with respect to the belt conveying surface 82a of the leading edge of the sheet S conveyed by the means 6. The main difference is that the control means 43A, the paper detection sensor 39, the home position sensor 40, and the stepping motor 110 are removed.

  The rush angle varying means 129 includes a coupling member 110 that couples and fixes the pulley shafts 83b and 84b of the belt conveyance means 8B, a timing belt pulley 112 that is fixed to the coupling member 110 around the pulley shaft 83b, and a first conveyance. The feed gear 120 fixed to the shaft 61 a of the feed roller 61 in the means 6, the feed idler gear 121 rotatably supported by the housing 80 in the vicinity of the feed gear 120, and the shaft of the feed idler gear 121. It is mainly composed of a timing belt pulley 122 connected on the same axis via a torque limiter (not shown) and a timing belt 113 stretched between the timing belt pulley 112 and the timing belt pulley 122. A torque limiter (not shown) is interposed between the shaft of the feed idler gear 121 and the timing belt pulley 122. The set torque of the torque limiter is set to such an extent that the belt conveying means 8B can be swung and is not damaged.

The initial position (home position) of the belt conveyance unit 8B in the second modification is the same as the initial position of the belt conveyance unit 8B in the first modification. Since the configuration around the belt conveying unit 8B, the connecting member 110, and the timing belt pulley 112 is the same as that of the first modification, the description thereof is omitted.
In a state where the belt conveying means 8B occupies the home position, the belt conveying means 8B may be held at its position by its own weight. It is preferable to hold at the home position by a catcher or urging means (not shown). As an urging means (not shown), for example, it is stretched between a lower end in the drawing of the connecting member 110 and a pin (not shown) planted on the stationary member of the open / close guide 79, and the belt conveying means 8B occupies the home position. It may be a tension spring that urges the spring. In the following description, it is assumed that a tension spring (not shown) is attached.

Based on the above-described configuration, the operation of the main part will be described focusing on the differences from the first modification.
The operation by the user until the paper feeding operation is started is performed in the same manner as in the first modification. When the sheet feeding operation is started, first, the sheet feeding motor 23 of the drive mechanism 22 shown in FIG. 10 is driven to rotate, so that the feed roller 61, its shaft 61a, and the feed gear 120 fixed to the shaft 61a are moved. Starts rotation in the direction of arrow A1. Subsequently, the feed idler gear 121 meshing with the feed gear 120 rotates in the direction of the arrow B1. Further, the timing belt pulley 122 connected to the feed idler gear 121 via a torque limiter (not shown) rotates in the direction of arrow B1, and accordingly, the timing belt 113 travels and rotates in the direction of arrow C1, and finally The belt conveying means 8B is oscillated and displaced in the direction of arrow D1 with the pulley shaft 83b as the oscillating fulcrum. The belt conveying means 8B occupies a swing position having a rush angle smaller than the rush angle of the home position, and stops at the swing position when torque within a predetermined range is transmitted from a torque limiter (not shown).・ Retained.
At this time, a stopper member (not shown) is disposed on the housing 80 side so that the belt conveying means 8B does not swing more than a predetermined angle (a swing displacement angle that occupies the swing position), and the feed roller 61 is rotated. During this time, a predetermined driving force / torque is transmitted so that it can be held at the swing position. The subsequent operation unique to this modification is that the belt conveying means 8B occupies the swinging position while the feed roller 61 is rotated, so that it returns to the home position as in the third embodiment. 3rd execution except that the operation | movement which carries out rocking displacement from a home position to a rocking | fluctuation position is not performed just before the trailing edge of the paper S at least just leaves | separates the downstream edge 71b of the outline guide surface 71a. The configuration is the same as that of the embodiment, and the description thereof is omitted to achieve the same effect.
When the rotation of the feed roller 61 is stopped, the belt conveying means 8B is returned to and held at the home position by its own weight and the urging force of the tension spring by the idling action of the torque limiter (not shown).

  Next, for example, in the paper feeding device 3 shown in FIG. 19, a transport operation when the lowermost paper feed tray 51 and the paper transport device 5 'are selected as the predetermined paper feed stages will be described. The lowermost paper feed tray 51 and the paper transport device 5 'are selected by operation of a paper feed stage selection key or plain paper selection key or thin paper selection key (not shown) on the operation panel 48, and copy conditions are selected and set by various key operations. Thereafter, when the start switch is turned on, the sheet feeding operation from the lowermost sheet feeding tray 51 and the sheet conveying device 5 ′ is performed as in the conventional case. At this time, since the feed roller 61 of the sheet conveying device 5H is naturally not rotated and stopped, the belt conveying means 8B remains held at the home position shown in FIG.

Therefore, according to the second modification, the belt conveying means 8B has the characteristic effects of the respective examples according to the invention of the prior application described above, and the leading edge of the sheet with respect to the conveying surface 82a of the conveying belt 82 can be obtained. By configuring the rush angle θ to be changeable, specifically, by having the rush angle varying means 129 for displacing the belt transport means 8B in the direction to change the rush angle θ, the first transport path is more than the first transport means 6. Since the belt conveying means 8B is displaced at least before the leading edge of the sheet conveyed via A contacts the belt conveying surface 82a, the first conveying path is displaced in a direction in which the entry angle is reduced. The conveyance resistance received from the outer guide surface 71a and the inner guide surface 70a constituting A can be reduced as compared with the first and second examples described above, and the leading edge of the paper S Since the rush load on the belt conveyance surface 82a at the end or the tip is further reduced than in the first and second examples described above, the conveyance / rush load resistance can be further reduced, and a more stable feeding operation can be performed. It becomes possible.
Further, the single paper feed motor 23 is used as a drive source for the feed roller 61, and the driving force of this drive source can drive the rush angle varying means 129 of the belt conveying means 8B, so that a solenoid or a stepping motor can be driven. Since it is not necessary to use a single drive source and electrical mechanical parts, it is possible to realize cost reduction and energy saving of the apparatus.

(Modification 3 of the third embodiment)
With reference to FIG. 32, Modification 3 of the third embodiment will be described.
Modification 3 shown in FIG. 32 is different from the paper conveyance apparatus 5H of Modification 2 shown in FIG. 31 only in that a paper conveyance device 5J instead of the paper conveyance device 5H is used. The configuration of the third modification other than the differences is the same as that of the copying machine 1 shown in FIG. 19 of the first to third embodiments.

  As compared with the sheet conveying device 5H according to the modified example 2 shown in FIG. 31, the sheet conveying device 5J according to the modified example 3 is replaced with the first conveying unit 6 instead of the rush angle varying unit 129 as shown in FIG. The main difference is that the rush angle varying means 129A for displacing the belt conveying means 8B in the direction of changing the rush angle of the leading edge of the sheet S with respect to the belt conveying surface 82a at the leading edge of the conveyed paper S is mainly different.

The rush angle varying means 129A includes a coupling member 110 that couples and fixes the pulley shafts 83b and 84b of the belt conveyance means 8B, a timing belt pulley 112 that is fixed to the coupling member 110 around the pulley shaft 83b, and a first conveyance. The reverse gear 123 fixed to the reverse roller driving shaft 62 a of the reverse roller 62 in the means 6, the reverse idler gear 124 that is rotatably supported by the housing 80 near the reverse gear 123 and meshes with the reverse gear 123, and the reverse idler gear 124 The timing belt pulley 125 is coaxially connected to the shaft of the shaft via a torque limiter (not shown), and the timing belt 113 is stretched between the timing belt pulley 112 and the timing belt pulley 125. . A torque limiter (not shown) is interposed between the shaft of the reverse idler gear 124 and the timing belt pulley 125.
The method of setting torque of the torque limiter is the same as in the second modification. The home position of the belt conveyance unit 8B in the third modification is the same as that of the belt conveyance unit 8B in the second modification. Since the configuration around the belt conveying unit 8B, the connecting member 110, and the timing belt pulley 112 is the same as that of the second modification, the description thereof is omitted. In the state where the belt conveying means 8B occupies the home position, it is assumed that a tension spring (not shown) is attached as in the second modification.

Based on the above-described configuration, the operation of the main part will be described focusing on differences from the second modification.
As in the second modification, when the paper feeding operation is started, first, the paper feeding motor 23 of the drive mechanism 22 shown in FIG. 10 is rotationally driven, so that the reverse roller 62, its reverse roller driving shaft 62a and The reverse gear 123 fixed to the reverse roller drive shaft 62a starts to rotate in the direction of arrow E1. Subsequently, the reverse idler gear 124 meshed with the reverse gear 123 rotates in the arrow F1 direction. Further, the timing belt pulley 125 connected to the reverse idler gear 124 via a torque limiter (not shown) rotates in the direction of arrow F1, and accordingly, the timing belt 113 travels and rotates in the direction of arrow G1, and finally The belt conveying means 8B is rocked and displaced in the direction of arrow D1 with the pulley shaft 83b as a rocking fulcrum. The belt conveying means 8B occupies a swing position having a rush angle smaller than the rush angle of the home position, and stops at the swing position when torque within a predetermined range is transmitted from a torque limiter (not shown).・ Retained.
At this time, a stopper member (not shown) is disposed on the housing 80 side so that the belt conveying means 8B does not swing more than a predetermined angle (a swing displacement angle occupying the swing position), and the reverse roller 62 is rotated. During this time, a predetermined driving force / torque is transmitted so that it can be held at the swing position. The subsequent operation unique to this modification is that the belt conveying means 8B occupies the swinging position while the reverse roller 62 is rotated, and thus returns to the home position as in the third embodiment. 3rd execution except that the operation | movement which carries out rocking displacement from a home position to a rocking | fluctuation position is not performed just before the trailing edge of the paper S at least just leaves | separates the downstream edge 71b of the outline guide surface 71a. It is the same as that of the form and the modification 2, and since the same effect is produced, the description is abbreviate | omitted.
When the rotation of the reverse roller 62 is stopped, the belt conveying means 8B is returned to and held at the home position by its own weight and the urging force of the tension spring by the idling action of the torque limiter (not shown).
Next, in the paper feeding device 3 shown in FIG. 19 as in the second modification, when the lowermost paper feeding tray 51 and the paper transportation device 5 ′ are selected, the reverse roller 62 of the paper transportation device 5J is naturally rotated. Therefore, the belt conveying means 8B remains held at the home position shown in FIG.

Therefore, according to the third modification, in addition to the same basic effects as in the second modification, the single sheet feeding motor 23 is used as a drive source for the reverse roller 62, and the belt conveying means is driven by the driving force of this drive source. Since the 8B rush angle varying means 129A can be driven, it is not necessary to use a single drive source such as a solenoid or a stepping motor and electric mechanical parts, so that it is possible to realize cost reduction and energy saving of the apparatus. it can.
As described above, in Modifications 2 and 3, any one of the feed roller 61 shaft 61a and the reverse roller drive shaft 62a as the rotation shaft and the rush angle varying means 129 or 129A are connected via at least one torque limiter. It was a configuration example characterized by being connected.

From the contents described above, those skilled in the art can immediately understand and implement the following technical contents. That is, the third embodiment and the first to third modifications shown in FIGS. 22 to 32 are not limited to being applied to the belt conveying means 8A and 8B arranged in the outline direction of the combined flow path. It is clear that the present invention can be applied to the belt conveying means 8 arranged in the outer direction of the first conveying path A as in the first example shown in FIGS. May be.
In addition, as described in the section of the problem to be solved by the invention, the same problem as the prior application, i.e., a sheet having a relatively high rigidity such as cardboard or an envelope is provided on a conveyance path having a curvature portion with a small curvature radius. In addition to or independently of the problem that a stable feeding operation cannot be performed due to a jam or a conveyance failure when feeding, it is necessary to solve the problem with a simple and low-cost configuration. The purpose of this technology configuration is to solve the following problems.

That is, in the first, second, and twelfth technical configurations, in the first example related to the sheet conveying apparatus of the prior invention, a sheet (especially a cardboard or an envelope having a relatively high rigidity) on the conveying surface of the belt. The rush angle of the leading edge of the sheet (same below) can be changed, that is, by having rush angle variable means for displacing the belt conveying means in the direction of changing the rush angle, the rush load of the sheet on the belt conveying surface It is another object of the present invention to further reduce the conveyance resistance that the sheet receives from the first sheet conveyance path by further reducing and to perform a more stable feeding / conveying operation.
In the first technical configuration, a first conveying unit that conveys a sheet, and a sheet that is disposed on the downstream side of the first conveying unit in the sheet conveying direction and that is conveyed by the first conveying unit is the first conveying unit. A first conveying unit formed between a first conveying unit and a second conveying unit; a second conveying unit that forms a nipping unit that nipped and conveys the sheet in a sheet conveying direction different from the sheet conveying direction of the conveying unit; A sheet conveying path; and a belt conveying unit that is disposed in an outer direction of the first sheet conveying path and includes a belt that conveys the sheet toward the clamping unit, and a leading end portion of the sheet with respect to the conveying surface of the belt The sheet conveying apparatus is configured to be capable of changing the entry angle.
The second technical configuration is characterized in that in the sheet conveying apparatus described in the first technical configuration, there is a rush angle varying means for displacing the belt conveying means in a direction to change the rush angle.
According to a twelfth technical configuration, in the sheet conveying apparatus according to any one of the first to eleventh technical configurations (other than the first and second technical configurations will be described later), the sheet is a relatively high rigidity sheet. It is characterized by being.

  According to the first, second, and twelfth technical configurations, when the sheet conveyed by the first conveying unit is conveyed to the holding unit of the second conveying unit, the rush angle is displaced to a position where it becomes smaller. For example, a first outer guide member or an outer guide that constitutes the first sheet transport path is achieved by assisting the transport of the sheet while further reducing the entry load of the sheet onto the transport surface of the belt. The conveyance resistance received from the member can be further reduced, and a more stable feeding / conveying operation can be performed.

In the following third and twelfth technical configurations, after the leading edge of the sheet conveyed from the first sheet conveyance path is nipped by the nipping portion, the rush angle varying means is used to bring the belt conveying means to the initial position. The purpose is to save energy of the drive means (drive source) of the rush angle varying means by returning it.
According to a third technical configuration, in the sheet conveying apparatus described in the second technical configuration, the belt conveying unit is configured to be freely displaceable between an initial position and a position where the entry angle is smaller than the initial position. The leading end of the sheet conveyed from the first sheet conveyance path is nipped by the nipping unit, and then the rush angle varying unit is used to return the belt conveying unit to the initial position. And
According to the third and twelfth technical configurations, energy saving of the drive means (drive source) of the rush angle varying means can be achieved.

  In the same manner as described above, those skilled in the art can immediately understand and implement the contents of the following technical configuration based on the contents described above. That is, in the following fourth, fifth, seventh and twelfth technical configurations, in the second to sixth examples related to the sheet conveying device of the prior invention, the leading end of the sheet with respect to the conveying surface of the belt The rushing angle of the sheet can be changed, that is, by having the rushing angle varying means for displacing the belt conveying means in the direction of changing the rushing angle, the sheet can be further reduced in the rushing load on the belt conveying surface. An object of the present invention is to further reduce the conveyance resistance received from the first sheet conveyance path and perform a more stable feeding / conveying operation.

According to a fourth technical configuration, in the sheet conveying apparatus described in the first technical configuration, a second sheet conveying formed from the upstream of the second conveying unit to the second conveying unit and different from the first sheet conveying path. A path, a first sheet transport path, and a second sheet transport path join together on the upstream side of the second transport unit, and the belt transport unit includes an outline of the join transport path. It is arranged in a direction.
According to a fifth technical configuration, in the sheet conveying apparatus described in the fourth technical configuration, a direction in which a rush angle of the leading end of the sheet with respect to the conveying surface of the belt at the leading end of the sheet conveyed by the first conveying unit is changed. The belt conveying means displaces the belt conveying means, and the belt conveying means allows the conveyance of the sheet from the second sheet conveying path and is in the initial state in the arrangement state, and from the initial position. Also, it is configured to be freely displaceable from a position where the entry angle becomes small. When a sheet is conveyed from the second sheet conveyance path, the entry angle variable means is used to change the displacement of the belt conveyance means. The belt conveying means is prohibited and held at the initial position.
According to a seventh technical configuration, in the sheet conveying apparatus according to any one of the second to sixth technical configurations, the leading end portion of the sheet conveyed from the first sheet conveying path is at least a conveying surface of the belt. Before the contact, it is characterized in that the entry angle varying means is displaced in a direction in which the entry angle is reduced.

  According to the fourth, fifth, seventh, and twelfth technical configurations, the position where the rush angle is reduced when the sheet conveyed by the first conveying unit is conveyed to the holding unit of the second conveying unit. For example, a first outer guide member that constitutes a first sheet conveyance path by assisting sheet conveyance while further reducing the rush load of the sheet on the conveyance surface of the belt by the displaced belt. In addition, it is possible to further reduce the conveyance resistance received from the outer guide member and to perform a more stable feeding / conveying operation.

In the following sixth and twelfth technical configurations, after the leading edge of the sheet conveyed from the first sheet conveyance path is nipped by the nipping portion, the rush angle varying means is used to bring the belt conveying means to the initial position. The purpose is to save energy of the drive means (drive source) of the rush angle varying means by returning it.
According to a sixth technical configuration, in the sheet conveying apparatus according to the fifth technical configuration, after the leading end of the sheet conveyed from the first sheet conveying path is nipped by the nipping portion, the rush angle varying means is used. Then, the belt conveying means is returned to the initial position.
According to the sixth and twelfth technical configurations, after the leading edge of the sheet conveyed from the first sheet conveying path is nipped by the nipping portion, the rush angle varying means is used to bring the belt conveying means to the initial position. By returning, a sufficient conveying force is applied to the sheet by the conveyance by the clamping unit, so that the sheet can be smoothly conveyed. Therefore, the driving means (driving source) of the entry angle varying means Can save energy.

In the following eighth and twelfth technical configurations, the trailing edge of the sheet conveyed from the first sheet conveying path, that is, the leading edge of the sheet conveyed from the first sheet conveying path is the second conveying means. The rear end of the sheet nipped and conveyed by the clamping unit is arranged at least at the guide means (other than the belt, arranged downstream of the first conveying means and upstream of the second conveying means). The sheet is conveyed along the outer guide member other than the belt conveying means) and immediately before the outer guide is removed, the rush angle changing means is used to displace the belt conveying means in the direction in which the rush angle is reduced, thereby The object is to reduce the impact noise when the end or the rear end of the sheet comes into contact with the belt, and to reduce the splash sound at the rear end of the sheet.
According to an eighth technical configuration, in the sheet conveying apparatus according to any one of the second to seventh technical configurations, a rear end of the sheet conveyed from the first sheet conveying path is configured at least other than the belt. Before the exit of the guide means, the rush angle varying means is used to displace the belt conveying means in a direction in which the rush angle is reduced.
According to the eighth and twelfth technical configurations, it is possible to alleviate the impact when the rear end or the rear end of the sheet comes into contact with the belt, and to reduce the splash sound at the rear end of the sheet.

In the following ninth and twelfth technical configurations, an object is to reduce the cost of the apparatus by using an inexpensive and easy-to-control solenoid as the driving means for the rush angle varying means.
A ninth technical configuration is characterized in that, in the sheet conveying apparatus according to any one of the second to eighth technical configurations, a solenoid is used as a driving unit of the rush angle varying unit.
According to the ninth and twelfth technical configurations, it is possible to reduce the cost of the apparatus by using an inexpensive and easy-to-control solenoid as the driving means for the rush angle varying means.

In the following tenth and twelfth technical configurations, a drive motor (for example, a stepping motor) that is rotationally driven by pulse input is used as the drive means for the rush angle varying means, so that the rush angle can be changed at high speed, and the sheet interval It is possible to cope with even in the case of the device / sheet passing mode in which the time of the sheet is small, and at the time of contact, by slowing down the changing speed of the rush angle when the trailing edge or trailing edge of the sheet comes into contact with the belt conveyance surface The purpose is to alleviate the impact.
According to a tenth technical configuration, in the sheet conveying apparatus according to any one of the second to eighth technical configurations, a driving motor that is rotationally driven by a pulse input is used as a driving unit of the rush angle varying unit. Features.
According to the tenth and twelfth technical configurations, the rush angle can be changed (or switched) by using a drive motor (for example, a stepping motor) that is driven to rotate by pulse input as the drive means for the rush angle variable means. This is possible at high speed, and can be handled even in the apparatus / sheet passing mode in which the sheet interval time is small. Also, since the speed (or switching speed) for changing the rush angle is easy, when the rear end or the rear end of the sheet comes into contact with the conveyance surface of the belt, the speed of changing the rush angle (or switching speed) is set. By slowing down, it is possible to further reduce the impact at the time of contact.

In the following eleventh and twelfth technical configurations, rotation is achieved by connecting any one of a pair of rotating shafts constituting the first transport means and the rush angle varying means via at least one torque limiter. By configuring so that the displacement of the rush angle variable means can be performed in synchronization with the rotation of one of the shafts, it is not necessary to use electromechanical parts such as solenoids or stepping motors, reducing the cost of the equipment and saving energy. It aims to plan.
The eleventh technical configuration is the sheet conveying apparatus according to the second or fifth technical configuration, wherein the first conveying means includes a pair of rotating members each having a rotation shaft for nipping and conveying the sheet, One of the pair of rotating shafts and the entry angle varying means are connected via at least one torque limiter.
According to the eleventh and twelfth technical configurations, rotation is achieved by connecting any one of the pair of rotating shafts constituting the first conveying means and the rush angle varying means via at least one torque limiter. Since the displacement operation of the rush angle varying means is performed in synchronization with the rotation of one of the shafts (for example, the feed roller shaft or the reverse roller shaft), there is no need to use an electromechanical component such as a solenoid or a stepping motor. It is possible to realize cost reduction and energy saving of the device.

A thirteenth technical configuration is an image reading apparatus including the sheet conveying device according to any one of the first to twelfth technical configurations.
According to the thirteenth and twelfth technical configurations, it is possible to stably convey a relatively stiff original sheet such as a stiff recording paper such as thick paper and a special paper such as an envelope or a coated paper with a simple configuration and a low level. In addition to being able to realize and provide a costly image reading apparatus, it is possible to realize and provide an image reading apparatus that exhibits the effects of the above-described technical configurations.

A fourteenth technical configuration is an image forming apparatus including the sheet conveying device according to any one of the first to twelfth technical configurations and / or the image reading device according to the thirteenth technical configuration. .
According to the fourteenth technical configuration, it is possible to realize and provide a low-cost image forming apparatus that can stably transport stiff recording paper such as thick paper and special paper such as envelope and coated paper with a simple configuration. Accordingly, as an image forming apparatus having the image reading apparatus described in the thirteenth technical configuration, an image forming apparatus having the effects of the above technical configurations can be realized and provided.

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

  In the first to fourth examples and examples described above, the above-described embodiments, modifications, etc., as shown in FIG. 1, the lower paper feed stage is the belt conveying means, and the upper paper feed stage is conventional. Although it is an apparatus constituted by means, according to the necessity of feeding and transporting relatively rigid paper such as cardboard, the belt transport means according to the present invention is applied to the upper paper feed stage, Of course, the above-described embodiments of the present invention may be applied as appropriate.

In the first to sixth examples described above, as shown in FIG. 1, the present invention is conveyed from the sheet storage means (paper feed tray 51) in the image forming apparatus which is a copying machine to the image forming means main body. However, the present invention is not limited to this, and the image forming apparatus is not limited to this example, and the front end of the image forming apparatus is directed upward from the upper part of the fixing device 11 in the apparatus main body. A sheet conveying device (for example, see FIG. 33B) 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. Paper transport configured to be transported to the transport path It may be applied to the location.
That is, in the above first to sixth examples, 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. However, the present invention is not limited to this, and it is changed from a substantially horizontal direction to a downward downward direction (substantially vertical downward), or from a vertical downward direction or an upward direction to a substantially horizontal direction (for example, FIG. 33 (a)), or both may be in an oblique direction or the like.

  In the first to sixth examples and the like described above, both the first conveying means and the second conveying means are nipping and conveying means. However, depending on the conveying direction of each conveying means, the lower surface of the object to be conveyed. If it is only necessary to support and convey the sheet, it is not necessary to use a nipping / conveying means in which a nipping part is formed by the opposing member.

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

  In the first to sixth examples described above, the FRR paper feed method is adopted as the paper feed separation mechanism. However, the present invention is not limited to this. 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. It may be used, or a friction pad system having a configuration in which a friction pad as a fixing member is pressed into contact may be adopted. 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 sheet 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 related 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 is not limited to an in-body discharge type image forming apparatus that discharges paper between an image forming unit and a scanner, for example, and an image in which paper is discharged to a paper discharge tray provided on a side portion of the image forming apparatus main body. The present invention may also be applied to a forming apparatus. In addition, a paper path fed from the paper feeding device 3 is formed in a substantially vertical direction (substantially vertically upward) toward the upper portion of the image forming apparatus main body 2. The present invention is also applicable to an image forming apparatus in which the conveyance path until the sheet is discharged to the sheet discharge tray is not in a substantially vertical direction (substantially vertical direction).
The present invention relates to a sheet conveying apparatus for conveying a sheet (paper) from a sheet storage means (paper feed tray) or a sheet stacking means (paper feed table) to a printing unit main body in a printing apparatus including a stencil printing machine. May also be applied.

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

The present invention is not limited to a sheet conveying device arranged in a plurality of paper feeding stages. For example, in the paper feeding device 3 shown in FIG. 19, the upper paper feeding tray 51 and the paper conveying device 5 ′ are removed, The present invention can also be applied to a sheet conveying apparatus including only a single sheet feeding tray 51 and a sheet conveying apparatus 5.
That is, the present invention may be an image reading apparatus including the sheet conveying device according to any one of claims 1 to 13 described in the section for solving the above-described problems. In addition, the image forming apparatus may include the sheet conveying device according to any one of claims 1 to 13 and / or the image reading device. In the present invention, the image forming apparatus may be any one of a copying machine, a facsimile machine, a printer, a printing machine, and an ink jet recording apparatus, or a combined machine in which at least two of them are combined.

  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. It may be configured by appropriately combining them. (For example, the above-described embodiments and modifications of the present invention may be combined as appropriate, or the above-described embodiments of the present invention may be related to the prior invention.) It is possible for those skilled in the art to configure various embodiments, modifications, and examples within the scope of the present invention within the scope of the present invention, depending on the necessity and application. If so, it is clear.

1 is a schematic front view showing an overall configuration of an image forming apparatus having a paper transport device to which the present invention is applied. FIG. 2 is an enlarged cross-sectional view of a main part showing an operation state in which the leading edge of the paper reaches a belt conveying unit, showing the paper conveying device of FIG. FIG. 4 is an enlarged cross-sectional view of a main part showing an operation state immediately before the leading edge of the paper reaches the nip portion of the second transport means in the paper transport device of FIG. 2. FIG. 3 is an enlarged cross-sectional view of a main part of 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. 3 is a cross-sectional view of a main part showing a paper transport device different from FIG. 2 to which the present invention is applied and a paper feed tray stage around the paper transport device. FIG. 7 is an enlarged cross-sectional view of a main part showing an operation state in which the leading edge of the paper reaches the belt conveying means in the paper conveying device of FIG. 6. FIG. 7 is an enlarged cross-sectional view of a main part showing an operation state immediately before the leading edge of the paper reaches the nip portion of the second transport means in the paper transport device of FIG. 6. It is a schematic expanded sectional view which mainly shows another paper conveyance apparatus to which this invention is applied. FIG. 10 is a simplified perspective view showing a drive mechanism in a paper conveying apparatus of a fourth example. It is a schematic front view of the principal part of FIG. FIG. 10 is a perspective view of a main part when a periphery of a belt conveying unit in a paper conveying apparatus of a fourth example is viewed from a grip roller side. FIG. 10 is a perspective view of a main part when a periphery of a belt conveying unit in a paper conveying apparatus of a fifth example is viewed from a grip roller side. It is the perspective view which looked around the belt conveyance means in the paper conveyance apparatus of the 6th example from the grip roller side. It is a perspective view around the 1st and 2nd conveyance means and belt conveyance means in the paper conveyance device of the 6th example. (A) is a schematic perspective view showing a specific opening / closing configuration on the sheet feeding apparatus main body side in the sixth example, and (b) is an opening / closing guide opened when removing jammed paper (jam paper). It is a simplified sectional view of the important section showing the state. (A) is sectional drawing of the principal part which shows the trouble in the 6th example which concerns on prior invention, and the arrangement | positioning state of a belt conveyance means, (b) is the arrangement | positioning state of the belt conveyance means in 1st Embodiment. It is sectional drawing of the principal part shown. (A) is sectional drawing of the principal part which shows the problem in the 6th example which concerns on prior invention, and the arrangement | positioning / feeding operation state of a belt conveyance means, (b) is the belt conveyance means in 1st Embodiment. It is sectional drawing of the principal part which shows the arrangement | positioning and feeding operation state of this. 1 is a schematic front view illustrating an overall configuration of an image forming apparatus having a sheet conveying device according to a first embodiment of the present invention. FIG. 3 is a front view of a main part illustrating a paper transport device and a paper transport operation according to the first embodiment. (A) is a perspective view around the belt conveying means and the outer guide member in the second embodiment according to the present invention, and (b) is an enlarged cross-sectional view of the main part of (a). It is a front view of the principal part of the paper conveying apparatus which shows the 3rd Embodiment of this invention. FIG. 10 is a front view of a main part for explaining the operation of a sheet conveying apparatus in a third embodiment. It is a block diagram which shows the control structure of the principal part in 3rd Embodiment. FIG. 10 is a front view of a main part for explaining the operation of a sheet conveying apparatus in a third embodiment. FIG. 10 is a front view of a main part for explaining the operation of a sheet conveying apparatus in a third embodiment. FIG. 10 is a front view of a main part for explaining the operation of a sheet conveying apparatus in a third embodiment. It is a front view of the principal part explaining the paper conveying apparatus which shows the modification 1 of 3rd Embodiment, and its operation | movement. FIG. 10 is a front view of a main part for explaining the operation of the sheet conveying device according to Modification 1. It is a block diagram which shows the control structure of the principal part in the modification 1. FIG. It is a front view of the principal part of the paper conveying apparatus which shows the modification 2 of 3rd Embodiment. It is a front view of the principal part of the paper conveying apparatus which shows the modification 3 of 3rd 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, 5A to 5H, 5J Paper transport device (sheet transport device)
6 First conveying means (first conveying means)
7 Second transport means (second transport means)
8, 8A, 8B, 8C, 8D Belt conveying means (movement guide means)
9 Discharge tray 10 Photoconductor unit 10A Photoconductor 11 Fixing device 12 Developing device 13 Transfer device 22 Drive mechanism 23 Paper feed motor 43, 43A Control means 50 Bottom plate (sheet stacking means)
51 Paper feed tray (sheet storage means)
60 Pickup roller 61 Feed roller (one of the opposing pair of first conveying means, rotating member)
62 Reverse roller (the other of the opposing pair of the first conveying means, the rotating member)
61a Feed roller shaft (rotating shaft)
62a Reverse roller drive shaft (rotary shaft)
67 Manual feed tray 70 Inner guide member (inner guide member)
71 Outer guide member (first outer guide member, guide means)
71a Outer guide surface (first outer guide surface)
72 outline guide member (second outline guide member, outline guide member)
72a Longitudinal conveyance guide surface (second outline guide surface, outline guide surface)
79 Opening / Closing Guide (Sheet Conveyor Body)
80 Housing (sheet transport device main unit)
81 Grip roller (one of the opposite pair of the second conveying means, the rotation conveying driving means, the rotation conveying driving member, the rotating conveying member)
82 Conveying belt (belt as the other of the opposing pair of second conveying means)
82a Belt conveying surface (conveying surface of conveying belt)
83 pulley (constituting member of belt conveying means, first belt holding rotating member)
84 Pulley (constituting member of belt conveying means, second belt holding rotating member)
98 Solenoid (Driving angle variable means driving means)
114 stepping motor (driving angle variable means driving means, driving motor driven to rotate by pulse input)
99, 119, 129, 129A Entry angle varying means A First transport path (first sheet transport path)
B Second transport path (second sheet transport path)
R1 transport path R2 manual feed path R3 reverse transport path S paper (sheet / sheet-like recording medium, image forming medium)
Y Paper width direction (sheet width direction)
θ, θ1, θ2 Entry angle

Claims (15)

First conveying means for conveying a sheet;
Nipping that is arranged downstream of the sheet conveying direction of the first conveying unit 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. A second conveying means for forming a section;
A first sheet conveying path formed between the first conveying means and the second conveying means;
A second sheet conveying path that is formed from upstream of the second conveying means to the second conveying means, and is different from the first sheet conveying path;
A merged conveyance path where the first sheet conveyance path and the second sheet conveyance path merge on the upstream side of the second conveyance means;
Belt conveying means provided with a belt that is arranged in the outer direction of the merging conveyance path and conveys the sheet toward the clamping unit;
A first sheet is disposed in the outer direction of the first sheet conveying path between the first conveying unit and the belt conveying unit, and guides the sheet conveyed from the first conveying unit to the conveying surface of the belt. A first outer guide member having an outer guide surface;
A second outline provided with a second outline guide surface that is arranged in the outline direction of the second sheet conveyance path and guides the sheet conveyed from the upstream side of the second sheet conveyance path to the conveyance surface of the belt. A guide member,
The belt conveying means includes the belt, a first belt holding and rotating member disposed to face the holding portion for holding the belt so that the belt can run, and a second sheet conveying path facing the first belt holding rotating member. A second belt holding and rotating member disposed on the upstream side of
The first transport means comprises a pair of rotating members that sandwich and transport the sheet,
The second belt holding and rotating member is downstream of the second sheet conveying path from the axial center of the rotating member provided on the outline of the first conveying means and from the downstream end of the first outer guide surface. Is arranged upstream of the second sheet conveying path, and the belt conveying means is arranged so that the conveying surface of the belt protrudes outward from the second outer guide surface, and The amount of protrusion of the belt conveyance surface from the second outer guide surface is greater than that of the conveyance surface located upstream of the second sheet conveyance path with the downstream end of the first outer guide surface as a boundary. 2. A sheet conveying apparatus, wherein the sheet conveying apparatus is disposed so as to increase the number of the conveying surfaces positioned on the downstream side of the second sheet conveying path.   The sheet conveying apparatus according to claim 1, wherein the second belt holding and rotating member has an outer peripheral surface disposed on an inner side than the second outer guide surface.   The belt conveying means is disposed so that a conveying surface of the belt is positioned outside the second outer guide surface at least downstream of the first outer guide surface and downstream of the second sheet conveying path. The sheet conveying apparatus according to claim 1, wherein the sheet conveying apparatus is provided.   The belt conveying means is arranged so that a leading end portion of a sheet passing through a second sheet conveying path enters and contacts with an acute angle of incidence with respect to the conveying surface of the belt. Item 4. The sheet conveying apparatus according to any one of Items 1 to 3. First conveying means for conveying a sheet;
Nipping that is arranged downstream of the sheet conveying direction of the first conveying unit 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. A second conveying means for forming a section;
A first sheet conveying path formed between the first conveying means and the second conveying means;
A second sheet conveying path that is formed from upstream of the second conveying means to the second conveying means, and is different from the first sheet conveying path;
A merged conveyance path where the first sheet conveyance path and the second sheet conveyance path merge on the upstream side of the second conveyance means;
Belt conveying means disposed in the outer contour direction of the merging conveyance path, each including a belt that conveys the sheet toward the clamping unit, and three or more intermittently arranged in the sheet width direction;
An outer guide member provided with an outer guide surface that is arranged in the outer direction of the second sheet conveying path and guides the sheet conveyed from the upstream side of the second sheet conveying path to the conveying surfaces of the three or more belts. And
Each belt conveying means includes the belt, a first belt holding rotating member arranged to face the holding portion for holding the belt so that the belt can run, and a second sheet conveying to face the first belt holding rotating member. Comprising a second belt holding and rotating member disposed upstream of the path;
Of the three or more belt conveying means, the belt of the belt conveying means disposed at the center in the sheet width direction is longer in the second sheet conveying path direction than the belt of the other belt conveying means. And the amount of protrusion of the outer peripheral surface of the second belt holding and rotating member in the other belt conveying means from the outer guide surface and the outer peripheral surface of the second belt holding and rotating member in the other belt conveying means. The three or more of the three or more such that the amount of protrusion of the belt conveyance surface from the outline guide surface in the central belt conveyance means arranged corresponding to the position of protrusion from the outline guide surface is substantially the same. A sheet conveying apparatus comprising a belt conveying unit. A rush angle varying means for displacing the belt conveying means in a direction to change the rush angle of the leading edge of the sheet with respect to the conveying surface of the belt at the leading edge of the sheet conveyed by the first conveying means;
The belt conveyance unit is configured to allow conveyance of a sheet from a second sheet conveyance path and be freely displaceable between an initial position in the arrangement state and a position where the entry angle is smaller than the initial position. When the sheet is conveyed from the second sheet conveying path, the rush angle varying means is used to prohibit the displacement of the belt conveying means, and the belt conveying means is held at the initial position. The sheet conveying apparatus according to claim 1, wherein the sheet conveying apparatus is a sheet conveying apparatus.   The belt conveying means in a direction in which the rushing angle is reduced by the rushing angle varying means at least before the leading edge of the sheet conveyed from the first sheet conveying path comes into contact with the conveying surface of the belt. The sheet conveying apparatus according to claim 6, wherein the sheet conveying device is displaced.   The leading end of the sheet conveyed from the first sheet conveying path is nipped by the nipping unit, and then the rush angle varying unit is used to return the belt conveying unit to the initial position. Item 8. The sheet conveying apparatus according to Item 6 or 7.   Before the trailing end of the sheet conveyed from the first sheet conveyance path passes through at least the guide means constituted by other than the belt, the entry angle varying means is used to adjust the entry angle of the belt conveyance means. The sheet conveying apparatus according to claim 6, wherein the sheet conveying apparatus is displaced in a decreasing direction.   The sheet conveying apparatus according to any one of claims 6 to 9, wherein a solenoid is used as a driving unit of the rush angle varying unit.   10. The sheet conveying apparatus according to claim 6, wherein a driving motor that is rotationally driven by a pulse input is used as the driving means of the rush angle varying means. The first conveying means is composed of a pair of rotating members each having a rotation shaft for nipping and conveying the sheet,
8. The sheet conveying apparatus according to claim 6, wherein any one of the pair of rotating shafts and the entry angle varying means are connected via at least one torque limiter.   The sheet conveying apparatus according to claim 1, wherein the sheet is a sheet having relatively high rigidity.   An image reading apparatus comprising the sheet conveying apparatus according to claim 1.   An image forming apparatus comprising the sheet conveying device according to claim 1 and / or the image reading device according to claim 14.

Images