Sheet processing device and image forming device

Abstract

To secure an appropriate engagement distance between a drive gear and a rack part of a rack gear, by preventing over-constraint with respect to a shift unit.SOLUTION: A sheet processing device 100 comprises: a rack gear 307 which moves a registration shift unit 300 in a width direction by receiving drive force through a rack part 307a by a drive gear 402; a guide rail 400 which guides movement of the registration shift unit 300 in the width direction; and a backup bearing 404 which holds the rack gear 307 between the bearing and the drive gear 402 to support the rack gear 307. The rack gear 307 is rotatable relative to the registration shift unit 300 on a plane parallel to a conveyance direction and the width direction.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a sheet processing apparatus and an image forming apparatus equipped with the sheet processing apparatus. [Background technology]

[0002] In recent years, there has been a growing demand for higher quality output from image forming apparatuses that form images on sheets, such as printers. For this reason, many of the recent image forming apparatuses perform post-processing such as processing or binding on printed sheets.

[0003] In image forming apparatuses that perform such post-processing, mechanisms have been put into practical use that group sheets to simplify the post-processing, and shift the sheets in the width direction to different positions for each group to sort them into stacking trays. In recent years, there has been a demand for image forming apparatuses that increase the amount of shift in the width direction of sheets when shifting the sheets in the width direction to different positions for each group and discharging them, in order to meet market demands for compatibility with various media.

[0004] Patent Document 1 discloses a sheet processing device equipped with a sorting mechanism that shifts the widthwise position of a sheet by moving the sheet in a state where the sheet is sandwiched between a pair of conveying rollers arranged on a sheet conveying path. In the sheet processing device of Patent Document 1, the position of the shift unit is regulated by moving the shift unit, which supports the pair of conveying rollers, along a slide rail provided in the device body. In addition, in the sheet processing device of Patent Document 1, the position of the shift unit is regulated to ensure meshing of gears of a drive train connection part for transmitting drive from the device body to the shift unit.

[0005] However, in Patent Document 1, the positional restrictions at the above two points result in excessive constraints on the shift unit due to variations in dimensional tolerances of parts. Such excessive constraints on the shift unit are absorbed by distortion of parts or by loosening of gaps in the fitting portions between parts, which causes an inability to maintain appropriate backlash between gears.

[0006] As a result, the gears of the drive connection part become too close to each other, causing the tooth surfaces to hit the tooth bottom, increasing the load when driving the shift unit, or the gears become too far apart, causing backlash to increase and causing the amount of movement in the width direction of the sheet to deviate from the target amount of movement.

[0007] Therefore, in the sheet processing device of Patent Document 1, it is necessary to take measures such as adjusting the distance between the gears at the time of assembly so that the distance between the gears is appropriate. In this case, in the sheet processing device of Patent Document 1, it is necessary to adjust the distance between the gears so that the distance between the gears is appropriate over the entire width direction in which the shift unit moves. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Patent No. 4785474 Summary of the Invention [Problem to be solved by the invention]

[0009] However, in conventional sheet processing devices, when the amount of movement of the shift unit is increased and the component tolerances of the gears are taken into account, it becomes difficult to adjust the distance between the gears at the drive connection part between the shift unit and the device main body to be appropriate.

[0010] An object of the present invention is to provide a sheet processing apparatus and an image forming apparatus that can maintain an appropriate meshing distance between a drive gear and a rack portion of a rack gear by preventing excessive constraint on the shift unit. [Means for solving the problem]

[0011] The sheet processing device of the present invention is characterized in that it comprises a shift unit having a first pair of conveying rollers that clamp and convey a sheet, a drive gear to which a driving force is transmitted from a drive motor, and a rack portion that meshes with the drive gear, and moves the shift unit, which has a sheet clamped by the first pair of conveying rollers, in a width direction perpendicular to the conveying direction of the sheet by receiving the driving force from the drive gear via the rack portion, a guide member that guides the movement of the shift unit in the width direction, and a support member that clamps the rack gear between the drive gear and supports the rack gear, and the rack gear is rotatable relative to the shift unit on a plane parallel to the conveying direction and the width direction. Effect of the Invention

[0012] According to the present invention, excessive constraint on the shift unit can be prevented, so that the meshing distance between the drive gear and the rack portion of the rack gear can be set to an appropriate distance. [Brief description of the drawings]

[0013] [Figure 1] 1 is a schematic diagram of an image forming apparatus according to an embodiment of the present invention; [Diagram 2] 1 is a block diagram showing a configuration of an image forming apparatus according to an embodiment of the present invention; [Diagram 3] 1 is a schematic diagram of a sheet processing apparatus according to an embodiment of the present invention; [Figure 4] 2 is a perspective view of a registration shift unit of the sheet processing apparatus according to the embodiment of the present invention; FIG. [Diagram 5]1 is a perspective view of a state in which the sheet processing apparatus is supported by a guide rail according to an embodiment of the present invention; [Figure 6] 1 is a cross-sectional view of a sheet processing apparatus according to an embodiment of the present invention. [Figure 7] 1 is an enlarged cross-sectional view of a portion of a sheet processing apparatus according to an embodiment of the present invention. [Figure 8] 5 is a flowchart showing an operation of the sheet processing apparatus according to the embodiment of the present invention. [Figure 9] 5A to 5C are schematic diagrams illustrating an operation of the sheet processing apparatus according to the embodiment of the present invention. [Figure 10] 7A to 7C are schematic diagrams illustrating another operation of the sheet processing apparatus according to the embodiment of the present invention. [Figure 11] 5A to 5C are schematic diagrams illustrating the operation of a sheet processing apparatus to be compared with the sheet processing apparatus according to the embodiment of the present invention. [Figure 12] 11 is a schematic diagram of a modified example of the sheet processing apparatus according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, the embodiments will be described in detail with reference to the drawings.

[0015] <Configuration of Image Forming Apparatus> The configuration of an image forming apparatus 1 according to an embodiment of the present invention will be described in detail with reference to FIG.

[0016] Here, an intermediate transfer tandem type color image forming apparatus using an electrophotographic system is exemplified as the image forming apparatus 1. The intermediate transfer tandem type has a configuration in which four color image forming units are arranged side by side on an intermediate transfer belt, and has the advantage of being adaptable to a wide variety of sheets P and excellent in print productivity, and has become mainstream in recent years.

[0017] Specifically, the image forming apparatus 1 includes an image forming apparatus main body 2 and a sheet processing apparatus 100.

[0018] The image forming apparatus main body 2 is equipped with a mechanism for forming an image on a sheet P and discharging the sheet P on which the image has been formed to the sheet processing apparatus 100. The image forming apparatus main body 2 is equipped with an image forming section for forming an image on the sheet P. There are four sets of image forming sections, each having four colors: yellow (Y), magenta (M), cyan (C), and black (Bk). The image forming sections are not limited to the four sets of four colors, and may be a set of any color, such as a single color of black (Bk). The order of the colors yellow (Y), magenta (M), cyan (C), and black (Bk) is not limited to the order shown in FIG. 1, and may be any order. The configuration of the image forming apparatus main body 2 will be described in detail later.

[0019] The sheet processing apparatus 100 is a stacker that discharges and stacks the sheets P conveyed by the image forming apparatus main body 2. The sheet processing apparatus 100 shifts the position of the sheets P discharged from the image forming apparatus main body 2 in a width direction (hereinafter simply referred to as "width direction") perpendicular to the conveying direction of the sheets P, and sorts and stacks the sheets P. The configuration of the sheet processing apparatus 100 will be described in detail later.

[0020] <Configuration of Image Forming Apparatus Body> The configuration of the image forming apparatus main body 2 of the image forming apparatus 1 according to the embodiment of the present invention will be described in detail with reference to FIGS.

[0021] The image forming apparatus main body 2 includes a fixing device 5, photoconductors 11Y, 11M, 11C, and 11K, charging devices 12Y, 12M, 12C, and 12K, exposure devices 13Y, 13M, 13C, and 13K, and developing devices 14Y, 14M, 14C, and 14K. The image forming apparatus main body 2 also includes photoconductor cleaners 15Y, 15M, 15C, and 15K, an intermediate transfer belt 31, a secondary transfer inner roller 32, a drive roller 33, a tension roller 34, and primary transfer devices 35Y, 35M, 35C, and 35K.

[0022] The image forming apparatus main body 2 also includes a secondary transfer outer roller 41 and an adsorption conveying section 42. The image forming apparatus main body 2 also includes a transfer paper storage 61, a paper feed section 61a, a transfer paper storage 62, a paper feed section 62a, a transfer paper storage 63, a paper feed section 63a, a transfer paper storage 64, a paper feed section 64a, and a pair of registration rollers 76. The image forming apparatus main body 2 also includes a paper discharge section 77, a switching member 81, a reversing roller 86, a reversing roller 87, and a control section 200.

[0023] Photoconductors 11Y, 11M, 11C, and 11K, charging devices 12Y, 12M, 12C, and 12K, exposure devices 13Y, 13M, 13C, and 13K, and developing devices 14Y, 14M, 14C, and 14K execute an image forming process under the control of control unit 200. Furthermore, primary transfer devices 35Y, 35M, 35C, and 35K, and photoconductor cleaners 15Y, 15M, 15C, and 15K execute an image forming process under the control of control unit 200.

[0024] The image forming process is performed in parallel by the image forming units of Y, M, C, and Bk. The image forming process is performed at a timing when the toner image of the downstream color is superimposed on the toner image of the upstream color when the toner image is primarily transferred from the photoconductors 11Y, 11M, 11C, and 11K to the intermediate transfer belt 31 in each image forming unit.

[0025] The paper feed units 61a, 62a, 63a, 64a, and the pair of registration rollers 76 execute a conveying process of the sheet P under the control of the control unit 200. The fixing device 5, the secondary transfer outer roller 41, the suction conveying unit 42, and the paper discharge unit 77 constitute a conveying means that conveys the sheet P, on which an image has been formed by the image forming unit, to the sheet processing device 100.

[0026] The fixing device 5 applies a predetermined pressure to the sheet P conveyed by the suction conveying section 42 using a pair of opposing rollers or belts (both of which are omitted from the drawings), and also heats the sheet P using a heat source such as a heater (not shown). The fixing device 5 applies pressure to the sheet P and heats it, thereby melting and fixing the toner image secondarily transferred onto the sheet P, thereby forming a fixed image on the sheet P. The fixing device 5 conveys the sheet P on which the fixed image has been formed to the paper discharge section 77.

[0027] The photoconductors 11Y, 11M, 11C, and 11K are rotated by a driving force transmitted from a driving source (not shown).

[0028] The charging devices 12Y, 12M, 12C, and 12K uniformly charge the surfaces of the photoconductors 11Y, 11M, 11C, and 11K.

[0029] Under the control of the control unit 200, the exposure devices 13Y, 13M, 13C, and 13K form electrostatic latent images on the photoconductors 11Y, 11M, 11C, and 11K that have been uniformly charged by the charging devices 12Y, 12M, 12C, and 12K.

[0030] The developing devices 14Y, 14M, 14C, and 14K develop the electrostatic latent images formed on the photoconductors 11Y, 11M, 11C, and 11K by the exposure devices 13Y, 13M, 13C, and 13K with toner. The developing devices 14Y, 14M, 14C, and 14K develop the electrostatic latent images formed on the photoconductors 11Y, 11M, 11C, and 11K with toner to form toner images on the photoconductors 11Y, 11M, 11C, and 11K, thereby making the electrostatic latent images visible.

[0031] The photoconductor cleaners 15Y, 15M, 15C, and 15K collect the small amount of residual toner remaining on the photoconductors 11Y, 11M, 11C, and 11K, and prepare the photoconductors 11Y, 11M, 11C, and 11K for the next image formation.

[0032] The intermediate transfer belt 31 is stretched by a secondary transfer inner roller 32, a drive roller 33, and a tension roller 34, and is driven to be transported in a clockwise direction in FIG. 1. A full-color toner image is primarily transferred onto the intermediate transfer belt 31 from the photoconductors 11Y, 11M, 11C, and 11K by primary transfer devices 35Y, 35M, 35C, and 35K. The intermediate transfer belt 31 transports the primarily transferred full-color toner image to a toner image transfer nip portion formed by the secondary transfer inner roller 32 and the secondary transfer outer roller 41.

[0033] The inner secondary transfer roller 32 faces the outer secondary transfer roller 41 and forms a toner image transfer nip portion together with the outer secondary transfer roller 41 to transfer a toner image onto the sheet P. The inner secondary transfer roller 32 applies a predetermined pressure together with the outer secondary transfer roller 41 to the intermediate transfer belt 31 and the sheet P conveyed by the registration roller pair 76 in the toner image transfer nip portion.

[0034] The driving roller 33 is provided on the inner side of the intermediate transfer belt 31, and drives the intermediate transfer belt 31 to rotate when a driving force is transmitted from a driving source (not shown).

[0035] The tension roller 34 is provided on the inner side of the intermediate transfer belt 31 and applies tension to the intermediate transfer belt 31 .

[0036] The primary transfer devices 35Y, 35M, 35C, and 35K are given an electrostatic load bias and apply a predetermined pressure to the photoconductors 11Y, 11M, 11C, and 11K and the intermediate transfer belt 31. The primary transfer devices 35Y, 35M, 35C, and 35K are given an electrostatic load bias and apply a predetermined pressure, thereby primarily transferring the toner images formed on the photoconductors 11Y, 11M, 11C, and 11K onto the intermediate transfer belt 31.

[0037] The secondary transfer outer roller 41 applies an electrostatic load bias to the sheet P and intermediate transfer belt 31 transported by the registration roller pair 76 in a toner image transfer nip formed together with the secondary transfer inner roller 32. The secondary transfer inner roller 32 and the secondary transfer outer roller 41 secondarily transfer the toner image, which has been primarily transferred onto the intermediate transfer belt 31, onto the sheet P in the toner image transfer nip. The secondary transfer outer roller 41, together with the secondary transfer inner roller 32, transports the sheet P, onto which the toner image has been secondarily transferred, to the attraction transport section 42.

[0038] The suction conveying section 42 conveys the sheet P conveyed by the inner secondary transfer roller 32 and the outer secondary transfer roller 41 to the fixing device 5 by suctioning the sheet P with air using a fan or the like.

[0039] In the transfer paper storage 61, sheets P are stacked and stored.

[0040] The paper feed section 61a feeds the sheet P stored in the transfer paper storage 61 to the pair of registration rollers 76 in accordance with the image formation timing.

[0041] In the transfer paper storage 62, sheets P are stacked and stored.

[0042] The paper feed section 62a feeds the sheet P stored in the transfer paper storage 62 to the pair of registration rollers 76 in accordance with the image formation timing.

[0043] In the transfer paper storage 63, sheets P are stacked and stored.

[0044] The paper feed section 63a feeds the sheet P stored in the transfer paper storage 63 to the pair of registration rollers 76 in accordance with the image formation timing.

[0045] In the transfer paper storage 64, sheets P are stacked and stored.

[0046] The paper feed section 64a feeds the sheet P stored in the transfer paper storage 64 to the pair of registration rollers 76 in accordance with the image formation timing.

[0047] The pair of registration rollers 76 abuts the sheet P fed by the paper feed unit 61a, the paper feed unit 62a, the paper feed unit 63a, or the paper feed unit 64a, or the sheet P conveyed by the duplex conveying path 85, to form a loop in the sheet P. The pair of registration rollers 76 follows the leading edge of the looped sheet P to correct the skew. After correcting the skew of the sheet P, the pair of registration rollers 76 conveys the sheet P to the toner image transfer nip portion at a predetermined timing. Here, the predetermined timing is the timing of image formation on the sheet P, and specifically, the timing of aligning the position where the toner image on the sheet P is transferred to the position of the toner image carried on the rotating photoconductors 11Y, 11M, 11C, and 11K.

[0048] The sheet discharge section 77 conveys the sheet P conveyed by the fixing device 5 to the sheet processing device 100.

[0049] The switching member 81 swings between a position where the sheet P transported by the fixing device 5 is transported to the paper discharge transport path 82 and a position where the sheet P is transported to the reverse path 83 and the switchback path 84, by the action of a solenoid (not shown) controlled by the control unit 200. The switching member 81 swings to select a path for the sheet P. When the switching member 81 is in a position where the sheet P is transported to the paper discharge transport path 82, the switching member 81 enables the sheet P to be transported to the sheet processing device 100. When the switching member 81 is in a position where the sheet P is transported to the reverse path 83 and the switchback path 84, the switching member 81 enables the sheet P to be transported to the reverse path 83.

[0050] When images need to be formed on both sides of the sheet P, the reversing rollers 86 perform a switchback operation of rotating forward and backward to switch between the leading end and the trailing end in the conveying direction of the sheet P. The reversing rollers 86 rotate forward to draw the sheet P into the switchback path 84, and rotate reversely to convey the sheet P drawn into the switchback path 84 to the double-sided conveying path 85.

[0051] When images need to be formed on both sides of the sheet P, the reversing rollers 87 perform a switchback operation of rotating forward and backward to switch the leading end and trailing end in the conveying direction of the sheet P. The reversing rollers 87 rotate forward to draw the sheet P into the switchback path 84, and rotate reversely to convey the sheet P drawn into the switchback path 84 to the double-sided conveying path 85.

[0052] The control unit 200 controls the overall operation of the image forming apparatus 1 .

[0053] <Control Unit Configuration> The configuration of the control unit 200 of the image forming apparatus 1 according to the embodiment of the present invention will be described in detail with reference to FIG.

[0054] The control unit 200 includes an external I / F 201 , an image signal control unit 204 , a printer control unit 205 , a CPU circuit unit 206 , and a user operation unit 209 .

[0055] The external I / F 201 is an interface between the image forming apparatus 1 and an external computer 211. The external I / F 201 expands print data input from the computer 211 into a bitmap image and outputs it to the image signal control unit 204 as a digital image signal.

[0056] The image signal control unit 204 performs various processes on the digital image signal input from the external I / F 201 under the control of a CPU 203 (described later) of a CPU circuit unit 206 , and converts the digital image signal into a video signal to output to a printer control unit 205 .

[0057] Based on the video signal input from the image signal control unit 204, the printer control unit 205 drives the exposure devices 13Y, 13M, 13C, and 13K via an exposure control unit (not shown).

[0058] The CPU circuit unit 206 controls the overall operation of the image forming apparatus 1. Specifically, the CPU circuit unit 206 includes a CPU 203, a ROM 207, and a RAM 208.

[0059] A CPU 203 as a calculation means reads out and executes a control program stored in a ROM 207 to control the operation of the image forming apparatus 1, including the operation of a user operation unit 209. The CPU 203 collectively controls an image signal control unit 204, a printer control unit 205, and a sheet processing apparatus control unit 210, based on a key signal input from the user operation unit 209, while using a RAM 208.

[0060] The ROM 207 prestores a control program.

[0061] The RAM 208 temporarily holds control data input from the CPU 203 and is used as a working area for the calculation processing associated with the control in the CPU 203.

[0062] The user operation unit 209 includes a plurality of keys for setting sheet information such as the basis weight, size, and type of the sheet P, various functions related to image formation, and a display unit for displaying information indicating the setting state. The user operation unit 209 displays the corresponding plurality of keys or the above information on the display unit based on a signal from the CPU circuit unit 206. The user operation unit 209 outputs a key signal corresponding to the operation of each key displayed on the display unit to the CPU circuit unit 206.

[0063] <Configuration of the sheet processing device> The configuration of the sheet processing apparatus 100 according to the embodiment of the present invention will be described in detail with reference to FIGS.

[0064] The sheet processing apparatus 100 includes an entrance roller pair 101, a separation roller pair 102, an exit roller pair 103, a paper discharge roller pair 104, a lower stacking tray 105, an upper stacking tray 106, a post-registration roller pair 108, and an entrance sensor 109. The sheet processing apparatus 100 also includes a first switching member 120, a second switching member 121, a sheet processing apparatus control unit 210, a registration shift unit 300, a skew detection sensor 301, and a lateral registration detection sensor 302. The sheet processing apparatus 100 also includes a rack gear 307, a guide rail 400, a lateral registration shift motor 401, a drive gear 402, a motor gear 403, and a backup bearing 404.

[0065] The pair of inlet rollers 101 conveys the sheet P conveyed by the sheet discharge unit 77 of the image forming apparatus main body 2 to the pair of separation rollers 102 .

[0066] The separating roller pair 102 as the second conveying roller pair can be driven under the control of the sheet processing apparatus control unit 210 to be in a pressed state in which the sheet P is sandwiched and conveyed, or in a separated state in which the rollers are separated from each other. In the pressed state, the separating roller pair 102 conveys the sheet P conveyed by the inlet roller pair 101 to the registration shift unit 300, and is in the separated state when the sheet P reaches the registration shift unit 300.

[0067] The exit roller pair 103 discharges the sheet P conveyed by the post-registration roller pair 108 via the conveying path 107 to the outside. At this time, when another sheet processing device (not shown) is provided downstream of the sheet processing device 100, the exit roller pair 103 conveys the sheet P conveyed by the post-registration roller pair 108 via the conveying path 107 to the other downstream sheet processing device.

[0068] The pair of discharge rollers 104 discharges the sheet P conveyed by the pair of post-registration rollers 108 onto a lower stack tray 105 .

[0069] The lower stack tray 105 stacks sheets P discharged by the pair of paper discharge rollers 104. When the stacked sheets are to be removed after a job is completed or during a job, the lower stack tray 105 descends to a position where the sheets can be removed.

[0070] On the upper stacking tray 106, sheets P discharged by a post-registration roller pair 108 are stacked.

[0071] The post-registration roller pair 108 discharges the sheet P conveyed by the registration shift unit 300 onto the upper stacking tray 106 , or conveys the sheet P to the exit roller pair 103 or the paper discharge roller pair 104 .

[0072] The inlet sensor 109 detects the sheet P conveyed from the inlet roller pair 101 to the separation roller pair 102, and outputs an electric signal indicating the timing of delivery as the detection result to the sheet processing apparatus control unit 210.

[0073] The first switching member 120 switches, under the control of the sheet processing apparatus control unit 210, between a conveying path for discharging the sheet P conveyed by the post-registration roller pair 108 onto the upper stacking tray 106 and a conveying path for conveying the sheet P to the exit roller pair 103 or the discharge roller pair 104.

[0074] The second switching member 121 switches the conveying path 107 for conveying the sheet P conveyed by the post-registration roller pair 108 to the exit roller pair 103 and the conveying path for conveying the sheet P to the discharge roller pair 104 under the control of the sheet processing apparatus control unit 210.

[0075] The sheet processing apparatus control unit 210 is provided in the sheet processing apparatus 100, and controls the operation of the entire sheet processing apparatus 100 by exchanging information with the CPU circuit unit 206 of the control unit 200. The sheet processing apparatus control unit 210 controls the driving of the separation roller pair 102 based on an electrical signal input from the entrance sensor 109. The sheet processing apparatus control unit 210 controls the driving of the registration roller driving motor L310a and the registration roller driving motor R310b based on an electrical signal input from the skew detection sensor 301, thereby correcting the skew of the sheet P.

[0076] The sheet processing apparatus control unit 210 controls the driving of the lateral registration shift motor 401 to move the registration shift unit 300 in the width direction based on an electric signal input from the lateral registration detection sensor 302. Note that the sheet processing apparatus control unit 210 is not limited to a configuration in which it is provided in the sheet processing apparatus 100, and may be configured to be integrated into the CPU circuit unit 206 and control the sheet processing apparatus 100 from the image forming apparatus main body 2.

[0077] The registration shift unit 300 moves in the width direction under the control of the sheet processing apparatus control unit 210. The registration shift unit 300 conveys the sheet P conveyed by the separation roller pair 102 to the post-registration roller pair 108. The configuration of the registration shift unit 300 will be described in detail later.

[0078] The skew detection sensor 301 is provided at both ends in the width direction in a pair. The skew detection sensor 301 detects the sheet P conveyed from the registration shift unit 300 to the post-registration roller pair 108, and outputs an electric signal according to the detection result to the sheet processing apparatus control unit 210.

[0079] A lateral registration detection sensor 302 as a sheet position detection means detects the position of the edge of the sheet P in the width direction in the registration shift unit 300, and outputs an electric signal to the sheet processing apparatus control unit 210 according to the detection result.

[0080] The rack gear 307 includes a rack portion 307a having teeth that mesh with the drive gear 402. The rack gear 307 includes a rotation center portion 308 that is supported by the registration shift unit 300 so as to be rotatable relative to the sheet processing apparatus main body of the sheet processing apparatus 100 and the registration shift unit 300. The rack gear 307 is supported rotatably about the rotation center portion 308 relative to the registration shift unit 300. The rotation center portion 308 is located at a connection portion between the rack gear 307 and the registration shift unit 300 on an extension line of the reference pitch line H of the rack portion 307a.

[0081] The rack gear 307 is provided on the support base 306 so that the reference pitch line H is approximately parallel to the moving direction of the registration shift unit 300 and the guide direction of the two guide rails 400. When the drive gear 402 is driven to rotate, the rack gear 307 receives a driving force transmitted from the drive gear 402 via a rack portion 307a, thereby moving the registration shift unit 300 in the width direction.

[0082] The guide rail 400 as a guide member supports the registration shift unit 300 so as to be movable in the width direction, and guides the movement of the registration shift unit 300 in the width direction.

[0083] A lateral registration shift motor 401 serving as a drive motor is fixed without rotating relative to the sheet processing apparatus main body of the sheet processing apparatus 100. A motor shaft of the lateral registration shift motor 401 is connected to a motor gear 403. The lateral registration shift motor 401 is driven under the control of the sheet processing apparatus control unit 210 to rotate the motor gear 403, thereby transmitting a driving force to the motor gear 403.

[0084] The drive gear 402 is fixed and does not rotate with respect to the sheet processing apparatus main body of the sheet processing apparatus 100. The drive gear 402 meshes with the motor gear 403, and thereby rotates when the motor gear 403 rotates, and transmits the driving force of the motor gear 403 to the rack gear 307 of the registration shift unit 300.

[0085] The motor gear 403 is fixed and does not rotate with respect to the sheet processing apparatus main body of the sheet processing apparatus 100. The motor gear 403 is inserted into and connected to a motor shaft of the lateral registration shift motor 401. The motor gear 403 is rotated when the lateral registration shift motor 401 is driven.

[0086] The backup bearing 404 as a support member is fixed without rotating relative to the sheet processing apparatus main body of the sheet processing apparatus 100. The backup bearing 404 supports the rack gear 307 by sandwiching the rack gear 307 together with the drive gear 402. The backup bearing 404 supports the rack gear 307 by making point contact with the rack gear 307. The backup bearing 404 supports the rack gear 307 while rotating on the rack gear 307 when the rack gear 307 moves or rotates.

[0087] <Configuration of the register shift unit> The configuration of the registration shift unit 300 of the sheet processing apparatus 100 according to the embodiment of the present invention will be described in detail with reference to FIGS.

[0088] The registration shift unit 300 includes a registration guide 303a, a registration guide 303b, a registration driven roller 304, a slide bearing 305, a support base 306, a registration roller L309a, and a registration roller R309b. The registration shift unit 300 also includes a registration roller drive motor L310a, a registration roller drive motor R310b, and a roller holding member 311. The registration driven roller 304 and the registration roller L309a, and the registration driven roller 304 and the registration roller R309b form a first conveying roller pair.

[0089] The register guide 303a is fixed to the register guide 303b and is integrated with the register guide 303b.

[0090] The register guide 303 b is fixed to a support base 306 and is integrated therewith.

[0091] The registration driven roller 304 is rotatably supported by a roller holding member 311. The registration driven roller 304 is biased by a spring (not shown) in a direction in which the registration driven roller 304 abuts against the registration roller L309a and the registration roller R309b, thereby generating a roller abutment pressure for conveying the sheet P together with the registration roller L309a and the registration roller R309b.

[0092] Six slide bearings 305 are provided, and are in contact with the guide rail 400 in a rotatable and movably manner.

[0093] A register guide 303b is fixed to the support base 306. A rotation center portion 308 of a rack gear 307 is rotatably connected to the support base 306.

[0094] The registration roller L309a is rotated by being driven by a registration roller drive motor L310a. The registration roller L309a is rotated to correct skew of the sheet P conveyed by the separation roller pair 102, and conveys the sheet P conveyed by the separation roller pair 102 to the post-registration roller pair 108 together with the registration driven roller 304.

[0095] The registration roller R309b is rotated by being driven by a registration roller drive motor R310b. The registration roller R309b is rotated to correct skew of the sheet P conveyed by the separation roller pair 102, and conveys the sheet P conveyed by the separation roller pair 102 to the post-registration roller pair 108 together with the registration driven roller 304.

[0096] The registration roller driving motor L310a is fixed to the support base 306. The registration roller L309a is press-fitted onto the motor shaft of the registration roller driving motor L310a. The registration roller driving motor L310a is driven under the control of the sheet processing apparatus control unit 210 to rotate the registration roller L309a. The registration roller driving motor L310a can change the rotation speed of the registration roller L309a independently of the rotation speed of the registration roller R309b.

[0097] The registration roller driving motor R310b is fixed to the support base 306. The registration roller R309b is press-fitted onto the motor shaft of the registration roller driving motor R310b. The registration roller driving motor R310b is driven under the control of the sheet processing apparatus control unit 210 to rotate the registration roller R309b. The registration roller driving motor R310b can change the rotation speed of the registration roller R309b independently of the rotation speed of the registration roller L309a.

[0098] The roller holding member 311 is provided on the registration guide 303a.

[0099] <Overall operation of sheet processing device> The overall operation of the sheet processing apparatus 100 according to the embodiment of the present invention will be described in detail with reference to FIG.

[0100] The sheet processing apparatus 100 starts operating when the main power supply of the image forming apparatus 1 is turned on.

[0101] First, the sheet processing apparatus control unit 210 determines that the sheet P has reached the registration rollers L309a and R309b based on an electrical signal input from the entrance sensor 109 (S11). Specifically, the sheet processing apparatus control unit 210 determines that the sheet P has reached the registration rollers L309a and R309b after a predetermined time has elapsed since the sheet P was detected by the electrical signal input from the entrance sensor 109. Here, the predetermined time can be calculated by, for example, adding a value that takes into consideration the conveying speed and the variation in part tolerance to a value obtained by dividing the distance between the entrance sensor 109 and the registration rollers L309a and R309b by the conveying speed of the sheet P.

[0102] Next, the sheet processing apparatus control section 210 performs control to separate the pair of separation rollers 102 from each other (S12).

[0103] Next, the sheet processing apparatus control unit 210 detects the amount of skew of the sheet P based on the electrical signal input from the skew detection sensor 301 (S13). Specifically, the sheet processing apparatus control unit 210 detects the amount of skew of the sheet P from the time difference between the time when the sheet P passes the skew detection sensor 301 provided on one end side in the width direction and the time when the sheet P passes the skew detection sensor 301 provided on the other end side in the width direction.

[0104] Next, the sheet processing apparatus control section 210 calculates the rotation speed and the rotation time of the registration roller driving motor L310a and the registration roller driving motor R310b required to correct the skew of the sheet P based on the detected amount of skew of the sheet P (S14).

[0105] Next, the sheet processing apparatus control unit 210 executes skew correction of the sheet P by rotating the registration roller L309a and the registration roller R309b to the calculated rotation speed for the calculated rotation time (S15). At this time, the sheet processing apparatus control unit 210 corrects the skew of the sheet P by providing a rotation speed difference between the registration roller L309a and the registration roller R309b.

[0106] Next, the sheet processing apparatus control section 210 detects the position of the edge in the width direction of the sheet P based on an electrical signal input from the lateral registration detection sensor 302 (S16).

[0107] Next, the sheet processing apparatus control unit 210 calculates the rotation speed and rotation time of the lateral registration shift motor 401 as parameters for moving the sheet P to a target position in the width direction based on the detection result of the position of the width direction end of the sheet P (S17).

[0108] Next, the sheet processing apparatus control section 210 performs a lateral registration shift operation by controlling the driving of the lateral registration shift motor 401 so that the calculated rotation speed is reached in the calculated rotation time (S18). Here, the lateral registration shift operation is an operation for moving the sheet P, which is sandwiched between the registration roller L 309a, the registration roller R 309b and the registration driven roller 304, to a target position in the width direction. This allows the sorting shift of the sheet P and correction of the end position in the width direction. The lateral registration shift operation will be described in detail later.

[0109] Next, the sheet processing apparatus control unit 210 switches the path using the first switching member 120 and the second switching member 121 in accordance with a selection instruction indicated by an electrical signal input from the user operation unit 209 to the CPU circuit unit 206, and transports and discharges the sheet P (S19).

[0110] Specifically, when the user designates the upper stacking tray 106 as the loading position of the sheet P, the sheet processing apparatus control unit 210 switches the first switching member 120 to transport the sheet P toward the upper stacking tray 106. When the user designates transport to another sheet processing apparatus (not shown) at a subsequent stage, the sheet processing apparatus control unit 210 switches the first switching member 120 and the second switching member 121 to transport the sheet P toward the pair of exit rollers 103 via the transport path 107. When the user designates the lower stacking tray 105 as the loading position of the sheet P, the sheet processing apparatus control unit 210 switches the first switching member 120 and the second switching member 121 to transport the sheet P toward the pair of paper discharge rollers 104.

[0111] When the stacked sheets P are to be removed after the job is finished or during the job, the sheet processing apparatus control section 210 lowers the lower stack tray 105 to a position where the sheets can be removed.

[0112] In the above operation, for example, the conveying speed of the sheet P is 1000 mm / sec, and the time required for the minimum size sheet P, which has a length of 203 mm in the conveying direction, to pass through the registration rollers L309a and R309b is 203 msec. The time required to move the sheet P in the width direction is 75 msec, and the maximum movement amount of the sheet P in the width direction is 26 mm.

[0113] <Horizontal registration shift operation> The lateral registration shift operation performed by the sheet processing apparatus 100 according to the embodiment of the present invention will be described in detail with reference to FIGS.

[0114] In Figure 9, Figure 9(a) shows a state in which the amount of movement of the registration shift unit 300 in the width direction is greater than that in Figure 9(b), and Figure 9(b) shows a state in which the amount of movement of the registration shift unit 300 in the width direction is smaller than that in Figure 9(a).

[0115] 10, FIG. 10(a) shows a state in which the amount of rotation of the rack gear 307 is greater than that in FIG. 10(b), and FIG. 10(b) shows a state in which the amount of rotation of the rack gear 307 is smaller than that in FIG. 10(a).

[0116] 11 shows, for comparison with this embodiment, a configuration in which rotation center 308 of rack gear 307 is shifted in a direction perpendicular to reference pitch line H (the vertical direction in FIG. 11).

[0117] As shown in FIG. 9, when the reference pitch line H of the rack gear 307 is substantially parallel to the two guide rails 400, the registration shift unit 300 moves in the y direction, which is the width direction, along the guide rails 400 by forward and reverse rotation of the lateral registration shift motor 401.

[0118] At this time, since the rotation center 308 is on an extension of the reference pitch line H, a rotation moment about the rotation center 308 is less likely to be generated in the rack gear 307 compared to the case in which the rotation center 308 is shifted in a direction perpendicular to the reference pitch line H as shown in Fig. 11. This allows the sheet processing apparatus 100 to efficiently convert the driving force transmitted from the lateral registration shift motor 401 to the rack gear 307 via the motor gear 403 and the driving gear 402 into a force that moves the registration shift unit 300 in the y direction.

[0119] 10, the rack gear 307 rotates relative to the sheet processing apparatus main body of the sheet processing apparatus 100 and the registration shift unit 300 on a plane parallel to the transport direction and the width direction (a plane parallel to the paper surface of FIG. 10). In this state, when the registration shift unit 300 moves in the y direction, only the rack gear 307 rotates relative to the registration shift unit 300, and the abutment point G and the position of the teeth where the rack portion 307a meshes with the drive gear 402 move.

[0120] This makes it possible to prevent excessive constraint on the registration shift unit 300. Also, by preventing excessive constraint on the registration shift unit 300, it is possible to make the meshing distance between the drive gear 402 and the rack portion 307a of the rack gear 307 an appropriate distance. Furthermore, it is possible to keep the distance L between the shaft center of the drive gear 402 and the reference pitch line H constant, and it is possible to properly regulate the meshing distance of the gears.

[0121] Furthermore, the backup bearing 404 comes into contact with an abutment portion G on the opposite side to the rack portion 307a of the rack gear 307 to restrict the movement of the rack gear 307, and also rotatably supports the rack gear 307 at the abutment portion G. At this time, since the backup bearing 404 and the rack gear 307 are in point contact with each other at the abutment portion G, it is possible to minimize the contact resistance between the rack gear 307 and the backup bearing 404 when the rack gear 307 moves or rotates in the y direction.

[0122] In this embodiment, there is a rack gear 307 that receives a driving force from the driving gear 402 via a rack portion 307a to move the registration shift unit 300 holding the sheet P in the width direction. The rack gear 307 is rotatable relative to the registration shift unit 300 on a plane parallel to the conveying direction and the width direction. This prevents excessive restraint of the registration shift unit 300, and allows the meshing distance between the driving gear 402 and the rack portion 307a of the rack gear 307 to be an appropriate distance.

[0123] The present invention is not limited to the above-described embodiment, and it goes without saying that various modifications are possible without departing from the spirit and scope of the present invention.

[0124] Specifically, in the above embodiment, the movement of the register shift unit 300 is guided using the slide bearing 305, but this is not limiting, and the movement of the register shift unit 300 may be guided by movably engaging the support base 306 with the guide rail 400. For example, as shown in Fig. 12, the movement of the register shift unit 1300 may be guided by movably engaging the guide rail 400 with a round hole 1306a and an elongated round hole 1306b provided in the support base 1306. Note that in Fig. 12, the configuration of the register shift unit 1300 other than the support base 1306 is the same as the configuration of the register shift unit 300, and therefore description and illustration thereof will be omitted.

[0125] In the above embodiment, the separating roller pair 102 is provided on the upstream side of the registration shift unit 300 in the transport direction, but this is not limited to the above, and the separating roller pair 102 may be provided on the downstream side of the transport direction of the registration shift unit 300. Alternatively, the separating roller pair 102 is not limited to being provided on either the upstream side or the downstream side of the transport direction of the registration shift unit 300, and the separating roller pair 102 may be provided on both the upstream side and the downstream side of the transport direction of the registration shift unit 300.

[0126] In the above embodiment, the rotation center 308 of the rack gear 307 is rotatably connected to the support base 306. However, the present invention is not limited to this, and the rotation center 308 may be rotatably connected to a housing of the register guide 303a or the register guide 303b, etc., other than the support base 306 of the register shift unit 300. [Explanation of symbols]

[0127] L309a Register Roller L310a Registration roller drive motor R309b Registration roller L309b Registration roller drive motor 1. Image forming device 2. Image forming device main body 100 Sheet processing device 101 Inlet roller pair 102 Separation roller pair 103 Exit roller pair 104 Paper ejection roller pair 105 Loading tray 106 Stacking Tray 109 Inlet Sensor 120 Switching member 121 Switching member 200 Control section 203 CPU 206 CPU circuit section 209 User Operation Section 210 Sheet processing device control section 300 Reji Shift Unit 302 Side edge detection sensor 303a Cashier Guide 303b Cashier Guide 304 Register driven roller 305 Slide bearing 306 Support stand 307 Rack Gear 307a Rack section 308 Rotation center 309a Register Roller L 309b Register Roller R 310a Registration roller drive motor L 310b Registration roller drive motor R 400 Guide Rail 401 Lateral registration shift motor 402 Drive Gear 403 Motor Gear 404 Backup bearing

Claims

1. a shift unit including a first conveying roller pair for nipping and conveying a sheet; A drive gear to which a driving force is transmitted from a drive motor; a rack gear including a rack portion that meshes with the drive gear, the rack gear receiving the driving force from the drive gear via the rack portion to move the shift unit, with the sheet sandwiched between the first conveying roller pair, in a width direction perpendicular to the sheet conveying direction; a guide member that guides movement of the shift unit in the width direction; a support member for supporting the rack gear by sandwiching the rack gear between the support member and the drive gear; having The rack gear is The shift unit is rotatable on a plane parallel to the conveying direction and the width direction. A sheet processing apparatus comprising:

2. The rotation center of the rack gear is Located at a connection portion between the rack gear and the shift unit on an extension line of a reference pitch line of the rack portion, 2. The sheet processing apparatus according to claim 1,

3. The support member is Supporting the rack gear by making point contact with the rack gear; 3. The sheet processing apparatus according to claim 1, wherein the sheet is conveyed to the sheet conveying device.

4. The support member is When the shift unit is moved in the width direction by the rack gear, the rack gear is supported while rotating on the rack gear.

3. The sheet processing apparatus according to claim 1, wherein the sheet is conveyed to the sheet conveying device.

5. a sheet position detection means for detecting a position of the sheet in the width direction; a calculation means for calculating a parameter for moving the shift unit to a target position in the width direction based on a detection result by the sheet position detection means; having The shift unit includes: moving in the width direction in accordance with the parameter calculated by the calculation means; 3. The sheet processing apparatus according to claim 1, wherein the sheet is conveyed to the sheet conveying device.

6. a second conveying roller pair that is provided at least one of the upstream side and the downstream side in the conveying direction of the first conveying roller pair and that can be in a pressure contact state in which the second conveying roller pair sandwiches and conveys the sheet or in a separated state in which the second conveying roller pair is separated from the first conveying roller pair, The second conveying roller pair includes: The shift unit is in the separated state before moving in the width direction.

3. The sheet processing apparatus according to claim 1, wherein the sheet is conveyed in a direction parallel to the sheet conveying direction.

7. The sheet processing apparatus according to claim 1 or 2, an image forming unit that forms an image on a sheet; a conveying unit that conveys a sheet on which an image is formed by the image forming unit to the sheet processing device; An image forming apparatus comprising:

Images