JP2008280130A - Paper sheet conveying device and image forming device with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a conveying device capable of conveying paper sheets, while eliminating overlap of the paper sheets even if the paper sheets are overlapped in conveyance. <P>SOLUTION: In an image forming device 100, a paper sheet feeding section 400 comprises a paper sheet feeding mechanism 413 such as a paper sheet feeding cassette 402, a paper sheet sensor 415, a conveying section 430, a double-feed detecting section 91 and a drive control section 92. The paper sheet sensor 415 detects a paper sheet P passing through between the paper sheet supply mechanism 413 and the conveying section 430. The double-feed detecting section 91 determines whether the plural number of paper sheets P are delivered with a predetermined interval or not based on detection timing for detection of a tip of the paper sheet P by the paper sheet sensor 415. The drive control section 92, in the case wherein the double-feed detecting section 91 determines that the paper sheet P is not delivered with a predetermined interval between a preceding paper sheet P, controls the paper sheet supply mechanism so as to deliver a paper sheet P for a predetermined conveying time from the detection timing, and stops delivery of the paper sheet P for a time longer than a predetermined stop time, and thereafter, starts delivery again. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a sheet conveying apparatus including a sheet feeding cassette and an image forming apparatus including the sheet conveying apparatus.

  In recent years, in image forming apparatuses, the speed of image processing has progressed, and the number of sheets processed per unit time has increased, and it has become necessary to transport sheets at high speed. For this reason, when dealing with paper, dealing with so-called double feeding, in which a plurality of papers are carried in an overlapping manner, is also a problem.

As a sheet conveying apparatus mounted on such an image forming apparatus, there is a sheet conveying apparatus that discharges sheets without performing image processing when a plurality of sheets are conveyed in an overlapping manner (see, for example, Patent Document 1). ).
JP 2002-333797 A

  However, in the image forming apparatus disclosed in Patent Document 1, a large pressure is applied to the electrostatic latent image carrier (photosensitive member) when the overlapped sheets pass through the image processing unit, leading to deterioration of the photosensitive member. There was a problem.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a conveyance device that can eliminate the overlap of sheets even when the sheets are conveyed in a superimposed manner, and an image forming apparatus including the same.

  The paper transport device of the present invention includes a paper feed cassette, a paper feed mechanism, a transport unit, a sensor unit, a double feed detection unit, and a drive control unit. The paper feed cassette stacks and stores paper. The paper feed mechanism feeds paper from the paper feed cassette. The transport unit transports the paper fed out by the paper feed mechanism along a predetermined path. The sensor unit detects passage of a sheet between the sheet feeding mechanism and the transport unit. The double feed detection unit determines whether or not a plurality of sheets are fed out with a predetermined interval between them based on the detection timing at which the sensor unit detects the leading edge of the sheet. The drive control unit drives the paper feed mechanism at predetermined stop times so that a predetermined interval is formed between the respective sheets when a plurality of sheets are continuously conveyed. When it is determined by the double feed detection unit that the sheet is not fed out with a predetermined interval from the previous sheet, the drive control unit detects the sheet from the detection timing to the sheet for a predetermined conveyance time. , The paper feeding is stopped longer than a predetermined stop time, and the paper feeding is resumed. Here, the predetermined transport time includes a time set based on a time required for the paper to pass through the paper feed mechanism after the leading edge of the paper is detected by the sensor unit.

  In this configuration, the drive control unit detects that the sensor unit detects the leading edge of the sheet when it is determined by the double feed detection unit that the sheet has not been fed with a predetermined interval from the previous sheet. The paper is fed out by the paper feeding mechanism for a predetermined conveyance time from the timing. Then, the drive control unit stops the paper feeding longer than a predetermined stop time, and then restarts the paper feeding. Here, when the feeding of the sheet by the sheet feeding mechanism is stopped after a predetermined conveyance time has elapsed, among the sheets conveyed in a superimposed manner, the sheet positioned downstream in the conveying path has already passed through the sheet feeding mechanism. Therefore, it is transported along a predetermined path by the transport unit. On the other hand, the sheet positioned on the upstream side of the conveyance path stops because it has not passed through the sheet feeding mechanism. Further, by stopping the feeding of the sheet longer than a predetermined stop time and restarting the feeding of the sheet by the sheet feeding mechanism, it is possible to carry the sheet while ensuring the interval between the sheets.

  In this configuration, the double feed detection unit may determine that the sheet is not fed out with a predetermined interval when the rear end of the sheet is not detected by the sensor unit within a predetermined time from the detection timing. Here, the predetermined time includes a time normally required for the sensor unit to detect the trailing edge of the sheet from the detection timing. Accordingly, it is possible to determine whether or not the sheet is being fed out with a predetermined interval on the basis of the time normally required until the trailing edge of the sheet is detected by the sensor unit from the detection timing.

  Further, the paper feed mechanism may have a pressure roller that feeds out the paper. As a result, the pressure roller can be brought out in pressure contact with the paper stacked in the paper feed cassette.

  An image forming apparatus according to the present invention includes the sheet conveying device according to the invention described above, a conveyance adjusting unit, and an image processing unit. The conveyance adjusting unit adjusts the conveyance timing of the sheet conveyed from the sheet conveying apparatus and conveys the sheet. The image processing unit performs image processing on the sheet conveyed from the conveyance adjusting unit. The conveyance speed V1 for conveying the sheet from the paper feed mechanism to the conveyance adjustment unit and the conveyance speed V2 for conveying the sheet from the conveyance adjustment unit to the image processing unit satisfy the relationship of the expression (1). Here, the constant A is 1.5 ≦ A ≦ 2.0.

V1 ≒ A x V2 (1)
In this configuration, the transport speed V1 is about 1.5 to 2.0 times the transport speed V2. As a result, the conveyance speed of the sheet from the paper feed mechanism to the conveyance adjustment section becomes faster than the image processing speed in the image processing section. Therefore, even when the conveyance adjustment unit adjusts the conveyance timing for conveying the sheet to the image processing unit, the sheet can be conveyed one after another from the conveyance adjustment unit to the image processing unit.

  According to the present invention, even when sheets are transported in an overlapping manner, the overlap of the sheets can be eliminated and the sheets can be transported.

  Hereinafter, an image forming apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings.

<Configuration of Entire Image Forming Apparatus 100>
FIG. 1 is a schematic front sectional view of an image forming apparatus according to an embodiment of the present invention. An image forming apparatus 100 according to the present invention includes a scanner unit 200, an image forming unit 300, and a paper feeding unit (paper transport device) 400.

  The scanner unit 200 includes an automatic document feeder (ADF) 201, a first document table 202, a second document table 203, a first mirror base 204, a second mirror base 205, a lens 206, and a solid-state imaging device (CCD). : Charge Coupled Device) 207.

  The image forming unit 300 includes a photosensitive drum 31, a charger 32, an exposure device 33, a developing device 34, a transfer belt 35, a cleaner 36, and a fixing device 37 that constitute a process unit (image processing unit) 30. The photosensitive drum 31 has a photosensitive layer formed on the surface thereof, and rotates in the direction of the arrow.

  The charger 32 uniformly charges the surface of the photosensitive drum 31 to a predetermined potential. The charger 32 may use either a non-contact method using a charger or a contact method using a roller or a brush.

  The exposure device 33 irradiates the surface of the photosensitive drum 31 with light based on the image data. As a result, an electrostatic latent image is formed on the surface of the photosensitive drum 31 by the photoconductive action in the photosensitive layer. The exposure device 33 scans the laser beam modulated based on the image data in the axial direction of the photosensitive drum 31 through a polygon mirror. Alternatively, an exposure apparatus in which light emitting elements such as EL and LEDs are arranged in an array can be used.

  The developing device 34 supplies toner to the surface of the photosensitive drum 31 and visualizes the electrostatic latent image into a toner image.

  The transfer belt 35 is looped between a plurality of rollers below the photosensitive drum 31. Inside the loop-shaped movement path of the transfer belt 35, there is provided a transfer roller 35A that presses against the photosensitive drum 31 with the transfer belt interposed therebetween. The toner image carried by the photosensitive drum 31 is transferred to the paper P passing between the transfer belt 35 and the photosensitive drum 31.

  The paper feed unit 400 includes a control unit 90, paper feed cassettes 401, 402, 403, 404, a manual feed tray 405, a paper feed mechanism 413, a paper feed sensor 415 (see FIG. 2), and a transport unit 430. A plurality of sheets of the same size are stored in the sheet cassettes 401, 402, 403, and 404. On the manual feed tray 405, paper of a size or quality that is not frequently used is placed. The paper P stacked in each paper feed cassette is pulled out by a paper feed mechanism 413 (described in detail later) arranged corresponding to each paper feed tray, and each predetermined sheet is passed through the transport unit 430. Is transferred to the downstream process unit 30 along the transfer path.

  The paper feed mechanism 413 is disposed in each of the paper feed cassettes 401, 402, 403, and 404, and conveys the paper one sheet at a time to the downstream side.

  Here, the paper feed mechanism 413 arranged corresponding to the paper feed cassette 402 will be described as an example. FIG. 2 schematically shows the configuration of the conveyance path from the paper feed cassette 404 to the registration roller pair (conveyance adjustment unit) 411, that is, the configuration around the conveyance path A shown in FIG.

  As shown in FIG. 2, the paper feed mechanism 413 includes a paper feed roller 413A, a separating roller 413B, a transmission belt 413C, and a pickup roller (pressure roller) 413D.

  The paper feed roller 413A and the separating roller 413B sandwich the paper P conveyed from the upstream side of the conveyance path and convey it along the conveyance path A (see FIG. 1) to the downstream side of the conveyance path.

  The pickup roller 413D is driven by the paper feed roller 413A via the transmission belt 413C. When the paper P stacked on the paper cassette 404 is drawn out, that is, when the paper P is fed out, the paper P is moved downward from the retracted position above each paper cassette and stacked on each paper cassette. Press contact with the paper P. Further, when the pickup roller 413D is rotationally driven by the paper feed roller 413A, the stacked sheets P are conveyed to the downstream side along the conveyance path A one by one.

  The paper feed sensors 415 are arranged immediately downstream of the paper feed mechanisms 413 arranged corresponding to the paper feed cassettes 401, 402, 403, 404 and detect the passage of the paper P. More specifically, the operation of the paper feed sensor 415 will be described. When the paper P is not transported, the leading end of the paper feed sensor 415 is positioned so as to shield each transport path of the paper P, and is turned off. It is in a state. When the paper P is transported from the upstream side, the leading end of the paper feed sensor 415 is pushed down by the downstream leading end of the paper P and is turned on, and the passage of the paper P is detected.

  The transport unit 430 has a pre-registration roller pair 412. The pre-registration roller pair 412 transfers the paper P drawn from the paper feed mechanism 413 arranged corresponding to the paper feed cassettes 401, 402, 403, and 404 to the downstream registration roller pair (conveyance adjustment unit) 411. Transport.

  A plurality of roller pairs are arranged along the respective conveying paths that continue from the sheet feeding cassettes 401, 402, 403, and 404 to the pre-registration roller pair 412 to convey the sheet P to the downstream side.

  The pre-registration roller pair 412 is disposed at a position where each of the above-described conveyance paths merges into one conveyance path. Then, the paper P is conveyed to the registration roller pair 411 located on the downstream side.

  The registration roller pair 411 conveys the paper P to the process unit 30 located on the downstream side, and adjusts the conveyance timing and conveyance position of the paper P (so-called registration adjustment). In this embodiment, the registration roller pair 411 holds the leading end of the downstream side of the paper P, and the registration roller pair 411 adjusts the position of the paper P. At this time, the upstream end of the paper P is held by the pre-registration roller pair 412. Then, the registration roller pair 411 is conveyed toward the downstream side photosensitive drum 31 at a predetermined conveyance timing. When the sheet P is transported obliquely with a deviation from the normal transport position, that is, when the sheet P is transported in an inclined state with respect to the transport direction, correction of oblique transport is also performed.

  As shown in FIG. 2, the control unit 90 is disposed in the vicinity of the conveyance path A, and controls the driving of the registration roller pair 411, the paper feed mechanism 413, the conveyance unit 430, and the like. The control unit 90 includes a double feed detection unit 91 and a drive control unit 92 as functional blocks. Each functional block is formed by a control program stored in a storage device (not shown) being executed by a CPU (not shown) or the like.

  When the feed sensor 415 does not detect the upstream trailing edge of the paper P within a predetermined time after the paper feeding sensor 415 detects the downstream leading edge of the paper P, the double feed detection unit 91 detects It is determined that a plurality of sheets of paper P are transported in an overlapping manner. Here, the predetermined time refers to the passage of the upstream end of the sheet P by the sheet feed sensor 415 from the detection timing when the sheet P detects the passage of the leading end of the downstream side of the sheet P by the sheet feed sensor 415. This is the time that it normally takes to be detected.

  The drive controller 92 drives the paper feed roller 413A at predetermined stop times so that the paper P is pulled out one by one with a predetermined interval. If the multi-feed detection unit 91 determines that the paper P is being transported in an overlapping manner, the paper feed mechanism 415 feeds the paper P for a predetermined transport time after the paper feed sensor 415 detects the passage of the paper P. 413 is withdrawn. Further, the drive control unit 92 stops the drawing of the paper P longer than a predetermined stop time, and then restarts the drawing of the paper P.

  Here, the predetermined interval is an interval between the sheet P positioned on the downstream side and the sheet P positioned on the upstream side required for registration adjustment performed by the registration roller pair 411 (for example, about 30 to 50 mm). That is. The predetermined transport time is the time required for the paper P to pass through the paper feed mechanism 413 after the paper feed sensor 415 detects the leading edge on the downstream side of the paper P. In addition, the predetermined stop time is a time sufficient to ensure an interval (for example, about 30 to 50 mm) between the sheet P positioned on the downstream side and the sheet P positioned on the upstream side.

  As a result, when the conveyance by the paper feed mechanism 413 is stopped after a predetermined conveyance time has elapsed, the paper located on the downstream side passes through the paper feed mechanism 413 and is nipped and conveyed downstream. Therefore, it is possible to stop only the conveyance of the paper located on the upstream side. Further, by stopping the paper extraction from the paper supply mechanism 413 for a longer time than the predetermined stop time and then restarting the paper extraction, the papers on the upstream side also overlap on the downstream side. Can be transported without any problem. Here, the time longer than the predetermined stop time for stopping the drawing of the paper is, for example, by eliminating the overlap of the plurality of papers P in consideration of the transport speed of the papers P in each transport path. The interval may be a time that can secure about 30 to 50 mm. In addition, the interval for each sheet P may be further shortened if the registration adjustment time can be sufficiently secured. In this case, the above time can be further shortened.

  Here, the conveyance of the paper P conveyed along the conveyance path A will be described more specifically with reference to FIGS. 3 and 4.

  Normally, the sheets P1 are pulled out from the sheet feeding mechanism 413 one by one as shown in FIG. Then, as shown in FIGS. 3B and 3C, the sheet is conveyed to the pre-registration roller pair 412 and the registration roller pair 411 on the downstream side. The registration roller pair 411 finely adjusts the conveyance posture, conveyance timing, and the like of the paper P, and is further conveyed to the downstream process unit 30. Further, as shown in FIG. 3D, when the rear end on the upstream side of the paper P1 is separated from the paper feed sensor 415, the paper feed sensor 415 is turned off to detect the passage of the paper P1. When there is another image processing request, the pickup roller 413D is driven by the drive control unit 92, and the paper P2 is conveyed downstream.

  On the other hand, the case where the sheets P1 and P2 are transported in an overlapped state (that is, in a double feed state) will be described as follows.

  As shown in FIG. 4A, when the paper P1 and P2 pulled out from the paper feed cassette 402 by the paper feed mechanism 413 are conveyed to the downstream side in a so-called double feed state, The sheets P1 and P2 are conveyed to the immediately upstream side. At this time, when the two overlapped sheets P1 and P2 are caught by the separating roller 413B, a torque limiter (not shown) is actuated to rotate the separating roller 413B in the direction opposite to the conveying direction. As a result, the lower sheet P2 is returned to the upstream side. For this reason, as shown in FIG. 4B, the paper P2 stays immediately upstream of the separating roller 413B until the paper P1 passes through the paper feed mechanism 413. However, as shown in FIG. 4C, when the paper P2 passes through the paper feed mechanism 413 and is conveyed to the pre-registration roller pair 412 and the registration roller pair 411, the conveyance position and the like are adjusted. The rear end of the paper P2 may turn on the paper feed sensor 415, that is, keep it operating. In such a case, the paper feed sensor 415 is not turned off. Therefore, the passage of the trailing edge of the paper P1 cannot be detected, and the paper feed mechanism 413 continues to drive. As a result, as shown in FIG. 4C, the paper P2 is conveyed downstream by the paper feed mechanism 413. Then, as shown in FIG. 4D, a state occurs in which the rear end on the upstream side of the paper P1 and the front end on the downstream side of the paper P2 overlap in the region B.

  In such a case, the control unit 90 eliminates the overlap of the sheets P1 and P2 by the conveyance control described in detail later. In this embodiment, the paper roller P413 stays immediately upstream of the paper roller 413B until the paper paper P1 passes as shown in FIG. 4B due to the action of a torque limiter or the like (not shown). Explained with an example. In addition to the above, for example, from the state shown in FIG. 4B, the paper P2 is narrowed by the paper feed roller 413A and the paper feed roller 413B until the paper P1 completely passes between the paper feed roller 413B and the paper feed roller 413A. The present invention can also be applied to the case where the sheet is held and pulled out downstream, and is pulled out in a state where it partially overlaps the sheet P1. Note that the double feed state includes, for example, a state in which a plurality of sheets are pulled out with a part thereof being stacked, or a state in which the paper is conveyed.

  In the image forming apparatus 100, the conveyance speed V 1 for conveying the paper P from the paper feeding mechanism 413 to the registration roller pair 411 is about 2 of the conveyance speed V 2 for conveying the paper P from the registration roller pair 411 to the process unit 30. It is controlled by the control unit 90 so as to be doubled. Thereby, while image processing of the paper P1 is performed in the process unit 30, the paper P2 can be conveyed to the registration roller pair 411 and registration of the paper P2 can be adjusted. For this reason, it is suppressed that the waiting time for registration adjustment occurs and the supply of the paper P to the process unit 30 is delayed. As a result, the paper P can be continuously supplied to the process unit 30, thereby suppressing a decrease in image processing capability per unit time of the image forming apparatus 100 due to registration adjustment.

  In the image forming apparatus 100, the example in which the conveyance speed V1 is twice the conveyance speed V2 has been described. However, the present invention is not limited to this. For example, the transport speed V1 may be changed from 1.5 times to about twice the transport speed V2 in consideration of the length of the transport path and the time required for registration adjustment.

  Here, the conveyance control of the paper P in the paper supply unit 400 will be described with reference to the flowchart showing the flow of the conveyance control in the control unit 90 shown in FIG.

  When the image processing request is received in step S1, the control unit 90 automatically switches from the standby state to the image processing mode, and selects one of the paper feeding cassettes 401, 402, 403, 404 according to the image processing request. Select one. Then, the drive control unit 92 drives the paper feed mechanism 413 corresponding to the selected paper feed cassette. Here, a case where the paper feed cassette 402 is selected will be described.

  In step S <b> 2, the double feed detection unit 91 detects the passage of the downstream end of the paper P by the paper feed sensor 415. More specifically, the paper feed sensor 415 changes from an OFF state to an ON state to detect passage of the downstream end of the paper P.

  In step S3, the double feed detection unit 91 determines whether or not the sheets P are overlapped and conveyed downstream. More specifically, for example, the double feed detection unit 91 measures the time after the passage of the leading edge on the downstream side of the paper P is detected in step S2. When the passage of the upstream end of the sheet P is not detected within a predetermined time after the passage of the downstream end of the sheet P is detected, that is, when the paper feed sensor 415 is kept on. Determines that the paper P is overlapped and conveyed downstream. Then, the process proceeds to step S4.

  In step S <b> 4, the double feed detection unit 91 drives the paper feed mechanism 413 for a predetermined conveyance time to convey the paper P to the pre-registration roller pair 412. When a predetermined conveyance time has elapsed, the driving of the paper feed mechanism 413 is stopped in step S5. At this time, the pre-registration roller pair 412 is driven by the drive control unit 92. Here, when the paper feed mechanism 413 is driven for a predetermined transport time, the paper P positioned on the downstream side among the paper P being transported in an overlapping state passes through the paper feed mechanism 413. Then, the paper P positioned on the downstream side is conveyed to the registration roller pair 411 by the pre-registration roller pair 412. On the other hand, the paper P positioned on the upstream side stops in a state of being pinched by the paper feeding mechanism 413 and is not conveyed downstream. As a result, the state in which the sheets P are conveyed while being overlapped is eliminated.

  In step S <b> 6, the drive control unit 92 determines whether or not the set stop time of the paper feed mechanism 413 has elapsed. Here, the set time is a time longer than the predetermined stop time, and is a time for sufficiently securing an interval with the paper P positioned on the downstream side. When the set stop time has elapsed, in step S7, the drive control unit 92 resumes driving of the paper feed mechanism 413. As a result, the upstream sheet P is conveyed to the registration roller pair 411 while ensuring a predetermined interval between the downstream end of the downstream sheet P.

  In the image forming apparatus 100 according to the above-described embodiment, when the paper P is transported by the paper feeding unit 400, it is possible to prevent the paper P from being overlapped and transported to stop the image forming apparatus 100. There is also an effect that the processing efficiency can be improved.

  Further, since the overlapped sheets P do not pass through the process unit 30, it is possible to obtain an effect of suppressing deterioration of the photosensitive drum 31 and the like.

  In the above embodiment, an example in which the sheet conveying device is mounted on the image forming apparatus has been described. However, the present invention is not limited to this. For example, the sheet conveying apparatus according to the present invention can also be applied to an apparatus having a paper feed cassette other than the image forming apparatus. Also in this case, the same effect as that of the sheet conveying apparatus according to the above embodiment can be obtained.

  In addition, it should be thought that description of the above-mentioned embodiment is an illustration in all the points, Comprising: It is not restrictive. The scope of the present invention is shown not by the above embodiments but by the claims. Furthermore, the scope of the present invention is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

1 is a diagram illustrating an overall configuration of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a schematic diagram illustrating a configuration and functional blocks of a sheet feeding unit provided in the image forming apparatus illustrated in FIG. 1. FIG. 3 is a schematic diagram illustrating a normal sheet conveyance state in the sheet feeding unit illustrated in FIG. 2. FIG. 3 is a diagram illustrating a sheet conveyance state when a plurality of sheets are conveyed while being overlapped in the sheet feeding unit illustrated in FIG. 2. 3 is a flowchart illustrating a flow of conveyance control in the paper feeding unit illustrated in FIG. 1.

Explanation of symbols

30 Process part (image processing part)
DESCRIPTION OF SYMBOLS 90 Control part 91 Double feed detection part 92 Drive control part 100 Image forming apparatus 300 Image forming part 400 Paper feed part (paper conveyance apparatus)
401, 402, 403, 404 Paper feed cassette 411 Registration roller pair (conveyance adjustment unit)
412 Pre-registration roller pair 413 Paper feed mechanism 413D Pickup roller (pressing roller)
413A Paper feed roller 430 Transport section P, P1, P2 Paper S Step

Claims (4)

A paper cassette that stacks and stores paper,
A paper feed mechanism for feeding paper from the paper cassette;
A transport unit that transports the paper fed by the paper feed mechanism along a predetermined path;
A sensor unit for detecting passage of paper between the paper feeding mechanism and the transport unit;
Based on the detection timing at which the sensor unit detects the leading edge of the paper, a multi-feed detection unit that determines whether or not a plurality of papers are fed out with a predetermined interval therebetween,
A drive control unit that drives the paper feed mechanism at predetermined stop times so that the gap is formed between the papers when a plurality of papers are continuously conveyed;
With
When it is determined by the multi-feed detection unit that the sheet is not fed out with the interval between the drive control unit and the previous sheet, the drive control unit performs a predetermined conveyance from the detection timing to the sheet feeding mechanism. The paper is fed out for a period of time, the paper feeding is stopped longer than the stop time, and the paper feeding is resumed.
Paper transport device. The multi-feed detection unit determines that the sheet is not fed out with the interval when the rear end of the sheet is not detected by the sensor unit within a predetermined time from the detection timing;
The sheet conveying apparatus according to claim 1. The paper feeding mechanism has a pressure roller for feeding out the paper,
The sheet conveying apparatus according to claim 1 or 2. A paper conveying device according to any one of claims 1 to 3,
A conveyance adjusting unit that adjusts and conveys the conveyance timing of the sheet conveyed from the sheet conveying apparatus;
An image processing unit that performs image processing on paper conveyed from the conveyance adjustment unit;
With
The transport speed V1 for transporting paper from the paper feed mechanism to the transport adjustment unit, and the transport speed V2 for transporting paper from the transport adjustment unit to the image processing unit are constants A 1.5 ≦ A ≦ 2. Satisfies the relationship of equation (1) as 0,
V1≈A × V2 (1)
Image forming apparatus.

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