JP4855148B2 - Sheet conveying apparatus, sheet processing apparatus, and image forming apparatus - Google Patents

Description

  The present invention includes a sheet conveying apparatus that conveys a sheet member (sheet-like recording medium—hereinafter referred to as a sheet) that has been carried in, and the sheet conveying apparatus, and performs predetermined processing, such as sorting, stacking, and binding, on the sheet. The present invention relates to a sheet processing apparatus that performs saddle stitching and discharges paper, and an image forming apparatus such as a copying machine, a printer, a printing machine, and a digital multi-function peripheral that are provided with the sheet processing apparatus integrally or separately.

In a paper processing apparatus such as a finisher, a plurality of sheets are transported at the same time after the sheets are temporarily retained for the purpose of increasing the time required for processing such as a stapling operation so as not to reduce the productivity of the entire apparatus. Some of them perform so-called pre-stack processing that earns substantial time. For example, the invention described in Patent Document 1 is known as such a pre-stack process. According to the present invention, a sheet output from a copier can be output without delaying or interrupting printing in the copier even when the paper discharged from the copier is organized and bound in the compiler. A turning chute branched from this output path is provided upstream of the output feed roller, and a turning gate is provided at the entrance of this chute. While the job set is organized and bound by the compiler tray, the subsequent first sheet is attached. Stopped by the output feed roller, reversed and sent upstream, temporarily stored in the chute through the gate, and when the second sheet passes through the gate, the feed roller returns the first sheet from the chute to the output path, The first sheet and the second sheet overlap each other and are discharged to the compiler tray.
JP-A-7-002417

  On the other hand, in recent years, pre-stack processing with large-size paper has also been performed. In this case, in addition to a normal size (hereinafter referred to as a first pre-stack sheet feeder), a large-size dedicated pre-stack sheet feeder (hereinafter referred to as a pre-stack sheet feeder) The second pre-stack sheet feeder is provided), and the two pairs of pre-stack sheet feeders are driven by the same motor for cost reduction.

  In this configuration, when the prestack process is performed at a normal conveyance linear speed, the first sheet of the next portion is moved before the rear end of the sheet bundle at the time of discharging and conveying the prestack sheet bundle passes through the second prestack sheet feeder. It will enter the first prestack sheet feeder and the line speed will not match, causing a problem. Also, if the sheet is transported at the same linear velocity, the next sheet is switched back after waiting for the trailing end of the preceding sheet bundle to exit the second prestack sheet feeder. Evacuation is not in time.

  Therefore, the problem to be solved by the present invention is to retain sheets with a simple configuration at a lower cost and to enable sheet processing with high productivity.

In order to solve the above problem, the first means includes a first conveyance path for guiding the sheet member to the processing tray, and a second branch that branches from the first conveyance path and temporarily retains the sheet member. A conveyance path, a first conveyance unit that conveys the sheet member in a direction opposite to the processing tray side and the processing tray side, and the sheet when the sheet member is reversed by the first conveyance unit Switching means for guiding the member to the second conveyance path, and the preceding sheet member temporarily retained in the second conveyance path and the following sheet member are overlapped to overlap the sheet member bundle In the sheet conveying apparatus having a function of conveying as the first conveying unit, the sheet conveying device is driven by the same drive source as the first conveying unit, and is provided closer to the processing tray than the first conveying unit, and the sheet member is disposed on the processing tray. And a second transport means for transporting in a direction opposite to the processing tray side, wherein the first transport means and the second transport means have a transport speed until the sheet member reaches a predetermined number of staying sheets. Assuming that the second speed is the first speed and the second speed is the transport speed when the sheet member is retained in the second transport path and then transported as a bundle of sheet members, the second speed is faster than the first speed. Then, the conveying speed until the sheet member enters the first conveying means until the sheet member reaches the predetermined number of stays is a third speed, and the next portion 1 conveyed immediately after the sheet member bundle Assuming that the transport speed until the first sheet member enters the first transport means is the fourth speed, the fourth speed is made faster than the third speed , and the second speed and the fourth speed are set. Are characterized by equal speeds .
In this case, before Ki搬 feed rate varies from sheet size group.
The second means is characterized by a sheet processing apparatus including the sheet conveying apparatus according to the first means.
The third means is characterized by an image forming apparatus including the sheet conveying apparatus according to the first means.

In the embodiment described later, the processing tray is denoted by reference numeral 13, the sheet member is denoted by sheets 1, 1a, 1b, the first conveying path is denoted by reference numeral A, the second conveying path is denoted by reference numeral B, and the first conveying path is denoted by reference numeral A. the transport means in the transport roller 6, the switching means switching claw 9, the second is the conveying means conveying roller 7, respectively corresponding, conveyor speed that are controlled by the C PU 32.

According to the present invention, it is possible to solve the problem that the line speed does not match and the problem that the retreat is not in time, so that it is possible to perform sheet processing while maintaining high productivity and causing no conveyance trouble .

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a diagram illustrating a schematic configuration of an image forming system (an image forming apparatus including a sheet processing apparatus) including a sheet processing apparatus (sheet processing apparatus) and an image forming apparatus according to an embodiment of the present invention. The image forming system according to the present embodiment includes an image forming apparatus 500 that forms an image on a sheet that is a sheet-like recording medium, and various post-processing such as alignment and binding with respect to the sheet discharged from the image forming apparatus 500 Is basically composed of a sheet post-processing apparatus 2 as a sheet processing apparatus for performing the above. The image forming apparatus 500 includes any one of a copying machine, a printer, a facsimile machine, or a multifunction machine in which these functions are combined, having a function of forming an image on a sheet. Since the image forming apparatus having these functions is a known one, and the function of this image forming apparatus is not the gist of the present invention, description thereof is omitted here. In addition to the alignment and binding functions, the sheet post-processing apparatus 2 has functions such as punching and folding. These are known configurations, and the specifications of the sheet post-processing apparatus 2 are as follows. It is set accordingly.

  The sheet post-processing apparatus 2 basically includes a receiving port 2a, a lower conveyance path 2b, an upper conveyance path (not shown), a sheet retention path (pre-stack path) B, a sheet processing unit 100, a discharge roller 18, and a discharge tray 3. It is configured. The receiving port 2a is an opening for receiving the paper 1 from the paper discharge port 500a of the image forming apparatus 500, and an inlet sensor S1 and an inlet roller pair 4 are provided in the paper conveyance path following the receiving port 2a.

  The sheet conveyance path on the downstream side of the entrance roller pair 4 is a lower conveyance path 2b that guides the sheet 1 to the sheet processing unit 100 side, and an upper conveyance path that leads the sheet 1 to the sheet discharge roller 18 side (details are omitted in the figure). The branch claw 2e is arranged at the branch point. This branching claw 2e is driven by a stepping motor (not shown) to switch the paper conveyance path.

  The lower transport path 2b is provided with a sensor S2 for detecting the paper 1 on the lower transport path 2b and the first transport roller 5 from the upstream side in the paper transport direction, and the paper staying path B is opposite to the paper transport direction at the lower end. It is provided so as to function as a guide when the switching claw 9 branches back at an angle at which the sheet to be received can be received. The first conveyance path A is a conveyance path from the position at which the switching claw 9 is disposed at the branch point to the sheet processing tray 13 of the sheet processing unit 100, and second and third conveyance roller pairs 6 and 7 are arranged. In addition, 8 pairs of tray paper discharge rollers are provided on the most downstream side. In the following description, a pair of roller pairs is omitted.

  The sheet processing unit 100 aligns the sheet transport direction, the processing tray 13 on which the sheet 1 is discharged and stacked, the alignment fence 10 that aligns the direction perpendicular to the sheet transport direction of the sheet 1 stacked on the process tray 13, and the sheet transport direction. The trailing edge fence 11, the tapping roller 14 that brings the paper 1 discharged onto the processing tray 13 toward the trailing edge fence 11, the stapler 12 that binds the bundle of sheets aligned on the processing tray 13, and the binding on the processing tray 13. The discharge mechanism includes a discharge belt 17 that discharges a bundle of sheets and a pair of discharge claws 15.

  The discharge belt 17 is stretched between the discharge roller 16 a and the driven roller 16 b, and discharges the sheet bundle from the discharge roller 18 onto the discharge tray 3 by one of the discharge claws 15. Reference numeral 1z indicates a sheet bundle.

FIG. 2 is a block diagram showing a control configuration of the image forming system according to the present embodiment.
In the figure, a control device 31 is composed of a microcomputer having a CPU 32, an I / O interface 33, etc., and includes switches on the control panel of the main body of the image forming apparatus 500, an inlet sensor S1, a sensor S2, and other sensors. Is input to the CPU 32 via the I / O interface 33. The CPU 32 controls various motors and solenoids based on the input signals. Further, the stapler 12 also controls a stapler drive motor and a stapler moving motor (not shown) to drive a staple needle at a predetermined position of the sheet according to an instruction from the CPU 32 and execute a binding operation of the sheet bundle.

  The sheet post-processing device 2 is controlled by the CPU 32 executing a program written in a ROM (not shown) while using a RAM (not shown) as a work area. In addition to the RAM, data necessary for control and processing is stored, for example, in an EPROM (not shown).

  In the image forming system configured as described above, the sheet 1 output from the image forming apparatus 500 enters the sheet post-processing apparatus 2 from the receiving port 2 a, detects the sheet 1 by the entrance sensor SN 1, and is transported by the transport roller 4. It is conveyed and guided to the lower conveyance path 2b by rotating the branching claw 2e counterclockwise in the figure. The paper 1 guided to the lower transport path 2b is further transported by the transport roller 5, and the switching claw 9 loaded with the spring pressure in the transport path direction is rotated counterclockwise by the moving force of the paper 1. Then, it passes through the first transport path A secured thereby, and is transported to the processing tray 13 by the transport rollers 6, 7 and 8. The switching claw 9 returns to the illustrated position by the tension of a spring (not shown) after the paper 1 has passed. The sheet 1 conveyed to the processing tray 13 falls by its own weight in the direction of arrow C, and is knocked down by the tapping roller 14, and the rear end of the conveying direction is aligned by the rear end fence 11. Then, the rear end of the sheet 1 is detected in advance by the sensor SN2, and the width direction is aligned by the alignment fence 10 after a time during which the sheet conveyance direction can be aligned. This operation is repeated to form the aligned sheet bundle 1z in the processing tray 13.

  The aligned sheet bundle 1z is stapled by the staple 12 and then moved in the direction of arrow D by the discharge claw 15 provided in parallel with the sheet conveying direction at the center of the processing tray 13. The discharge claw 15 is operated by a drive system (not shown) via a discharge belt 17 that is wound between the rollers 16a and 16b. The sheet bundle 1z moves in the direction of arrow E while being pushed by the discharge claw 15 at the rear end, is discharged by the paper discharge roller 18, and is stacked on the paper discharge tray 3.

  When prestack processing is performed as described above, prestack processing may be performed on a large size sheet in addition to the normal size. Therefore, in addition to the normal size, it is necessary to provide a pre-stack conveying roller dedicated to a large size. In order to reduce the cost, if these two pairs of pre-stack conveying rollers are driven by the same motor, the pre-stacking process at the normal conveying linear speed will result in the post-stacking of the pre-stacked sheet bundle when the pre-stacked sheet bundle is discharged and conveyed. Before the end passes through the large-size pre-stack conveyance roller, the first sheet of the next part enters the normal-size pre-stack conveyance roller, and the line speed does not match, causing a problem. Also, if the sheet is transported at the same linear speed, the first sheet is switched when the next sheet is switched back after waiting for the trailing end of the preceding sheet bundle to pass through the large-size pre-stack conveying roller. Evacuation is not in time. The present embodiment corresponds to such an operation.

  In FIG. 3, after the rear end of the first sheet 1a passes through the switching claw 9 (FIG. 3A), the transport rollers 6 and 7 rotate in reverse (the transport rollers 6 and 7 are the same drive source). 2) (FIG. 2 (b)). When the leading edge of the sheet P1 passes through the conveying roller 6 or bites into the nip of the conveying roller 6, the conveying roller 6 stops and the sheet P1 is conveyed. Stays in the paper staying path B (FIG. 2C). Next, the next sheet 1b is conveyed in the same manner as the sheet 1a and is conveyed so as to abut against the conveying roller 6 that has stopped after passing through the switching claw 9 (FIG. 2D). The transport roller 6 is driven to rotate forward at the timing when the sheet 1b hits, and the sheets 1a and 1b are joined and transported (FIG. 2 (e)). The timing at which the transport roller 6 starts to rotate forward is the time from when the paper detection sensor S2 disposed upstream of the staying path detects the leading edge of the paper 1b until the leading edge of the paper 1a reaches the transporting roller 6 in advance. It is set at the timing calculated from the conveyance line speed. Here, when the number of staying sheets is equal to or less than the predetermined number of staying sheets, the joined sheet bundle is transported to the sheet staying path B similar to the sheet 1a, and the operation of retaining the sheet bundle is performed. When the number of staying sheets reaches the predetermined number of staying sheets, the merged sheet bundle is conveyed as it is (FIGS. 2 (f), (g), (h)) and processed by the tray discharge roller 8 (FIG. 1). It is discharged to the tray 13.

  Here, the conveyance timing of the above operation will be described. The sheet for which the staying process is performed is transported to the sheet storage unit at a transporting linear speed as shown in FIG. 4, and this process is transported to a predetermined number of staying sheets at a normal transporting line speed. The first sheet conveying means in the claims corresponds to the conveying roller 6, and the second sheet conveying means corresponds to the conveying roller 7.

  FIG. 4 is a velocity diagram illustrating an example when two sheets are retained in the sheet retention path B and are conveyed while being overlapped with the next sheet. When the sheet reaches the predetermined number of staying sheets, the sheet bundle is conveyed at the timing when it merges with the sheet 1b, and discharged and conveyed to the processing tray 13. Subsequently, the next first sheet is transported to the first transport path A. Here, when the next first sheet 1a immediately after the pre-stacked sheet bundle is conveyed at a normal conveyance speed, the next sheet is fed before the trailing edge of the sheet bundle at the time of releasing and conveying the staying sheet bundle passes through the conveying roller 7. The eye paper 1a enters the transport roller 6, and the linear speed does not match, causing a problem. In addition, if the sheet is transported at the same linear speed, the first sheet cannot be retracted in time if the next first sheet is switched back after waiting for the trailing end of the preceding sheet bundle to pass through the transport roller 6. .

  In order to solve this problem, the next first sheet 1a immediately after the staying sheet bundle (in the figure, the state when the three sheets are being conveyed is shown, and the next first sheet corresponds to the P1 'sheet). Only the line speed is different from the normal line speed. In this embodiment, as shown in FIG. 4, the sheet is conveyed at a speed higher than the normal linear speed. Then, when the staying paper bundles merge, the next first sheet 1a stops to perform punch punching (a punch unit is not shown), for example. At the stage where the staying paper bundle is discharged and conveyed, the next first sheet 1 a passes through the conveyance roller 5 and enters the conveyance roller 6. As described above, the transport rollers 6 and 7 are the same drive source. Therefore, the speed of the next first sheet 1a is increased to the same speed as the discharge conveyance linear speed of the staying sheet bundle before entering the conveyance roller 6. The transport rollers 6 and 7 are at a constant speed, the transport roller 7 transports the staying paper bundle, and the transport roller 6 transports the next first sheet 1a. At the stage where the trailing edge of the staying paper bundle has passed the transporting roller 7 and the trailing edge of the first sheet of the next section has passed the switching claw 9, the transporting roller 6 stops and rotates backward to switch back to the paper staying path 2d. It is transported and stored as the next portion staying paper.

  In order to maintain productivity, it is necessary to perform different linear velocity control for each paper size group.

As described above, according to this embodiment,
1) Even if the driving sources of the conveyance rollers 6 and 7 are the same, the processing can be performed without causing a conveyance failure between sheets.
2) Productivity for each size can be maintained by performing different conveyance linear velocity control for each paper size group.
3) When processing a sheet bundle using the sheet staying path B, the first sheet immediately after the transporting process of the stored sheet bundle is transported to the sheet staying path B. The paper conveyance speed conveyed by the conveyance roller 6 can be conveyed at a speed higher than the normal conveyance speed, so that productivity can be improved.
There are effects such as.

  Note that this embodiment is the best embodiment of the present invention, and those skilled in the art can realize various alternatives, modifications, variations, and improvements from the content disclosed in this specification. It goes without saying that these are substantially included in the scope defined by the claims.

1 is a diagram illustrating a schematic configuration of an image forming system including a sheet processing apparatus and an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a block diagram illustrating a control configuration of the image forming system in FIG. 1. FIG. 7 is an operation explanatory diagram of the sheet post-processing apparatus in the embodiment. FIG. 6 is a velocity diagram illustrating an example when two sheets are retained in a sheet retention path and are conveyed while being overlapped with the next sheet.

Explanation of symbols

1, 1a, 1b Paper 2 Paper post-processing device (paper processing device)
2b Lower conveying path 2e Branching claw 4 Entrance rollers 5, 6, 7 Conveying roller 9 Switching claw 13 Processing tray 31 Control device 32 CPU
DESCRIPTION OF SYMBOLS 100 Paper processing part 500 Image forming apparatus A 1st conveyance path B Paper retention path (pre-stack path)

Claims (4)

A first conveyance path for guiding the sheet member to the processing tray;
A second conveyance path that branches from the first conveyance path and temporarily retains the sheet member;
A first member that conveys the sheet member in a direction opposite to the processing tray side and the processing tray side;
Conveying means,
Switching means for guiding the sheet member to the second conveying path when the sheet member is reversed by the first conveying means;
A sheet conveying apparatus having a function of superimposing a preceding sheet member that has been temporarily retained in the second conveying path and a subsequent sheet member and conveying the sheet member bundle as a bundle,
Driven by the same drive source as the first conveying means, provided closer to the processing tray than the first conveying means, and the sheet member in a direction opposite to the processing tray side and the processing tray side Having second conveying means for conveying;
The first conveying unit and the second conveying unit set the conveying speed until the sheet member reaches a predetermined number of staying sheets as the first speed, and after the sheet member is retained in the second conveying path, When the transport speed when transporting as a member bundle is the second speed, the second speed is made faster than the first speed,
The conveyance speed until the sheet member enters the first conveyance means until the sheet member reaches the predetermined number of stays is a third speed, and the next section 1 conveyed immediately after the sheet member bundle.
If the transport speed until the sheet member enters the first transport means is the fourth speed, the fourth speed is made faster than the third speed , and the second speed and the first speed 4. A sheet conveying apparatus , wherein the speeds of 4 are equal . The sheet conveying apparatus according to claim 1, wherein the conveying speed is different for each sheet size group . Features and to Resid over preparative processing apparatus that includes a sheet conveying device according to claim 1 or 2. An image forming apparatus characterized by comprising a sheet conveying apparatus according to claim 1 or 2.

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