JP2003204418A - Sheet processing apparatus and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent sheets from being fed in a stacked manner without measuring a thickness of the sheet. <P>SOLUTION: The sheet processing apparatus comprises a sheet stacking means for stacking a plurality of sheets, a sheet separating means for separating the plurality of the sheets on the stacking means one by one, and an image reading means for reading the image information of the sheet sent by the separating means. The apparatus sequentially stores the image information read by the reading means, and compares the image information with image information of the sheet to be newly read to sense the sending of the sheets in the stacked manner. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding apparatus for feeding sheets and an image forming apparatus having the sheet feeding apparatus.

[0002]

2. Description of the Related Art Conventionally, an image forming apparatus such as a copying machine is provided with modes such as a cover mode and an interleaving mode. In these modes, the image forming apparatus is provided on the first page, the last page or the intermediate page of a sheet. It is controlled so that a sheet provided from a cassette provided in the tray or a tray for feeding can be inserted. Therefore, it is possible to insert not only sheets from a single feeding stage but also bundles from other feeding stages, such as "cover", "interleaving paper", and "back cover". The same insertion process can be performed by feeding the "insertion sheet" from a special tray on which the "insertion sheet" is placed.

At this time, since the processing of the sheets to be inserted is a mere sheet conveying operation, both the number of inserted sheets (place) and the number of inserted sheets for each bundle are
It can be set arbitrarily. Then, with respect to the bundle in which this insertion sheet is inserted, processing as a bundle, that is, post-processing such as bundle discharge processing, binding processing, folding processing, bookbinding processing, in a finisher or the like attached to the image forming apparatus main body Can be applied.

Hereinafter, the operation modes for inserting sheets from the insertion sheet stage into the "cover", "interleaving paper", and "back cover" are collectively called "interleaving mode". In the method of supplying the insertion sheet from the cassette, at the timing of inserting the insertion sheet, the insertion sheet is fed from the cassette to the same conveyance path as the sheet on which the image is formed, and the fed insertion sheet is It is discharged through the transport path. here,
A fixing unit is arranged in the middle of the conveying path, and the inserted sheet passes through the fixing unit similarly to the sheet.

When a color image printed original is used as the insertion sheet, the quality of the printed image may be impaired due to the heat and pressure when the insertion sheet passes through the fixing section. Further, in recent years, with the spread of personal computers, color images have increased, and in many cases color copy paper / color print paper has been used as the insert sheet. When this color copy paper is supplied from a cassette, the color copy paper surface is The adhered oil or the like may lower the conveyance of the feeding mechanism and may significantly reduce the reliability of the sheet conveyance.

In addition, an insert sheet feeder for supplying an insert sheet is provided in a finisher, and the insert sheet is supplied from the finisher. Examples of this type of device include those described in JP-A-60-180894, JP-A-60-191932, and JP-A-60-204564. In the apparatuses described in these, specifically, the insertion sheet is supplied from the insertion sheet feeder to the finisher at a desired timing, conveyed and stored in the intermediate tray in the finisher, and loaded. The sheet discharged from the main body of the image forming apparatus is guided into the finisher, conveyed and stored in the intermediate tray, and stacked.

In order to carry out such an operation, it is necessary to preliminarily match the page order according to the image contents in the accommodating portion of the insertion sheet feeder and stack the same for the number of copies.
When the interleaf sheet mode is used by using the insert sheet feeder, each sheet fed from the insert sheet feeder must be reliably fed into the finisher.

Here, in the case of the insertion sheet, since there are various kinds of sheets / images, there is a difference from the color copy paper in stability when performing the operation of automatically separating / conveying. For example, one sheet may be fed by the insertion sheet feeder, but two sheets may be fed at the same time, so-called "double feeding" may occur. In that case, the order of the sheet bundles created thereafter may be out of order. There is a problem that ends up.

Therefore, an apparatus for automatically determining whether or not the sheets fed from the insertion sheet feeder are double-fed based on information such as the thickness of the fed sheets (Japanese Patent Laid-Open No. 11-116).
No. 101) has been developed. Examples of this type of device include a device that detects the thickness of a conveyed sheet and determines from the information whether or not multiple feeding has been performed, or a code is written on a part of the conveyed sheet, and the information is used to determine the weight. A device for judging whether or not it has been sent (Japanese Patent Laid-Open No. 5-344271) has been generally used.

[0010]

However, as described above, in the method of measuring the sheet thickness by arranging the double feed detection means, when the thickness of the fed sheet varies, the double feed is performed. It is difficult to determine whether or not there is a sheet, and when the sheets are being fed in a misaligned manner in the conveyance direction, it is necessary to measure the thickness of the sheet at a long distance with respect to the conveyance direction. . To solve this problem, there is also a method to detect double feed by writing a code on a part of the sheet and checking the code, but because unnecessary information is written on a part of the sheet. , Had the problem of degrading quality.

Therefore, an object of the present invention is to prevent double feeding of sheets without measuring the thickness of the sheets.

[0012]

To achieve the above object, a typical structure of the present invention is a sheet stacking means for stacking a plurality of sheets, and a plurality of sheets on the sheet stacking means one by one. A sheet separating unit that separates the image information into a sheet and an image reading unit that reads the image information of the sheet sent by the sheet separating unit. The image information read by the image reading unit is sequentially stored, and the stored image information and the new image information are newly stored. It is characterized in that double feeding of the sheet is detected by comparing the image information of the sheet to be read.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (Embodiment) The present invention will be described in detail below with reference to the drawings. (Overall Structure) FIG. 1 is a vertical cross-sectional view showing the structure of a main part of an image forming apparatus of the present invention. As shown in FIG. 1, the image forming apparatus includes an image forming apparatus main body 10, a folding device 400, and a finisher 500, and the image forming apparatus main body 10 includes an image reader 200 and a printer 300 that read a document image.

The image reader 200 includes a document feeder 100.
Is installed. The document feeder 100 feeds the documents set upward on the document tray one by one to the left from the first page, and feeds them one by one to the platen glass via a curved path.
The paper is fed from the left on the top 102, conveyed through the reading position to the right, and then discharged toward the external discharge tray 112.

When the original passes through the flow reading position on the platen glass 102 from left to right, the image of the original is read by the scanner unit 104 held at the position corresponding to the flow reading position. This reading method is generally called the original flow reading. Specifically, when the document passes through the flow reading position, the reading surface of the document is illuminated with the light of the lamp 103 of the scanner unit 104, and the reflected light from the document is reflected by the mirrors 105, 106, 107.
Through the lens 108. The light that has passed through the lens 108 forms an image on the imaging surface of the image sensor 109.

By transporting the document so as to pass from the left side to the right side of the flow reading position in this manner, the document orthogonal to the document transport direction is the main scanning direction, and the transport direction is the sub-scanning direction. A read scan is performed. That is, when the document passes through the flow reading position, the document image is read line by line in the main scanning direction by the image sensor 109 while the document is conveyed in the sub-scanning direction to read the entire document image. The image that has been intentionally read is converted into image data by the image sensor 109 and output. The image data output from the image sensor 109 is input as a video signal to the exposure control unit 110 of the printer 300 after being subjected to predetermined processing in an image signal control unit 202 described later.

It is also possible to read the original by feeding the original onto the platen glass 102 by the original feeding device 100, stopping the original at a predetermined position, and scanning the scanner unit 104 from left to right in this state. . This reading method is a so-called fixed original reading method.

When reading a document without using the document feeder 100, first, the user lifts the document feeder 100 to place the document on the platen glass 102 and scan the scanner unit 104 from left to right. Read the original. That is, when a document is read without using the document feeder 100, the document fixed reading is performed.

The exposure control section 110 of the printer 300 modulates and outputs laser light based on the input video signal, and the laser light is irradiated onto the photosensitive drum 111 while being scanned by the polygon mirror 110a. An electrostatic latent image corresponding to the scanned laser beam is formed on the photoconductor drum 111. Here, as will be described later, the exposure control unit 110 outputs laser light so that a correct image (an image that is not a mirror image) is formed during fixed document reading.

The electrostatic latent image on the photosensitive drum 111 is visualized as a developer image by the developer supplied from the developing device 113. A sheet is fed from each of the cassettes 114 and 115, the manual feeding unit 125, or the double-sided transport path 124 at the timing synchronized with the start of laser light irradiation, and the sheet is fed between the photoconductor drum 111 and the transfer unit 116. Transported in between.
The developer image formed on the photosensitive drum 111 is transferred onto the sheet fed by the transfer unit 116.

The sheet on which the developer image is transferred is the fixing unit 117.
Then, the fixing unit 117 fixes the developer image on the sheet by hot pressing the sheet. The sheet passing through the fixing unit 117 is discharged from the printer 300 to the outside (folding device 400) via the flapper 121 and the discharge roller 118.

Here, when the sheet is discharged with its image forming surface facing downward (face down), the sheet having passed through the fixing section 117 is once guided into the reversing path 122 by the switching operation of the flapper 121, and the sheet is conveyed. After the trailing edge has passed the flapper 121, the sheet is switched back and discharged from the printer 300 by the discharge roller 118.

Hereinafter, this discharge form is referred to as reverse discharge. This reverse discharge is performed when forming an image read by using the document feeder 100 or when forming an image sequentially from the first page such as when forming an image output from a computer. The subsequent sheet order will be the correct page order.

When a hard sheet such as an OHP sheet is fed from the manual feeding section 125 and an image is formed on this sheet, the image forming surface is directed upward without guiding the sheet to the reversing path 122. The sheet is discharged (face up) by the discharge roller 118.

Further, when double-sided recording for forming images on both sides of the sheet is set, the sheet is guided to the reverse path 122 by the switching operation of the flapper 121 and then conveyed to the double-sided conveyance path 124. Control is performed to re-feed the sheet guided to 124 between the photoconductor drum 111 and the transfer unit 116 at the timing described above.

The sheet discharged from the printer 300 is sent to the folding device 400. The folding device 400 performs a process of folding a sheet into a Z shape. For example, when an A3 size sheet or a B4 size sheet and folding processing is designated, the folding device 400 performs folding processing, and in other cases,
The sheet discharged from the printer 300 passes through the folding device 400 and is sent to the finisher 500. This finisher 500
Has a cover for insertion into the image-formed sheet,
An inserter 900 for feeding special sheets such as slip sheets is provided. The finisher 500 performs various processing such as bookbinding processing, binding processing and punching.

(System Block Diagram) Next, the configuration of the controller that controls the entire image forming apparatus is shown in FIG.
Will be described with reference to. FIG. 2 is a block diagram showing a configuration of a controller that controls the entire image forming apparatus shown in FIG.

The controller, as shown in FIG.
The CPU circuit unit 150 has a U circuit unit 150, and a CPU (not shown), a ROM 151, and a RAM 152 are built in each block 10 by a control program stored in the ROM 151.
1, 153, 201, 202, 209, 301, 401, 501 are collectively controlled. The RAM 152 temporarily holds control data and is used as a work area for arithmetic processing associated with control.

The document feeder control unit 101 includes a document feeder 1
00 is drive-controlled based on an instruction from the CPU circuit unit 150. The image reader control unit 201 performs drive control on the scanner unit 104, the image sensor 109, and the like described above, and transfers the analog image signal output from the image sensor 109 to the image signal control unit 202.

The image signal controller 202 includes an image sensor 109.
After converting the analog image signal from the above into a digital signal, each processing is performed, and this digital signal is converted into a video signal and output to the printer control unit 301. Also computer 2
The digital image signal input from 10 through the external I / F 209 is subjected to various processes, the digital image signal is converted into a video signal and output to the printer control unit 301. The processing operation by the image signal control unit 202 is controlled by the CPU circuit unit 150. The printer control unit 301 drives the above-mentioned exposure control unit 110 based on the input video signal.

The operation unit 153 has a plurality of keys for setting various functions related to image formation, a display unit for displaying information indicating the setting state, and the like, and outputs a key signal corresponding to the operation of each key to the CPU circuit unit. The information is output to 150 and corresponding information is displayed on the display unit based on the signal from the CPU circuit unit 150.

The folding device control unit 401 is mounted on the folding device 400, and controls the drive of the entire folding device by exchanging information with the CPU circuit unit 150.

The finisher control unit 501 includes the finisher 500.
The drive control of the entire finisher is performed by exchanging information with the CPU circuit unit 150. The details of this control will be described later.

(Folding Section) Next, the configurations of the folding device 400 and the finisher 500 will be described with reference to FIG. FIG. 3 is a diagram showing the configurations of the folding device 400 and the finisher 500 of FIG.

As shown in FIG. 3, the folding device 400 introduces the sheet discharged from the printer 300, and the finisher 5
It has a folding conveyance horizontal path 402 for leading to the 00 side. A conveyance roller pair 403 and a conveyance roller pair 404 are provided on the folding conveyance horizontal path 402.

A folding path selection flapper 410 is provided at the exit of the folding conveyance horizontal path 402 (on the finisher 500 side). The folding path selection flapper 410 performs a switching operation for guiding the sheet on the folding conveyance horizontal path 402 to the folding path 420 or the finisher 500 side.

Here, when the folding process is performed, the folding path selection flapper 410 is turned on and the sheet is guided to the folding path 420. The sheet guided to the folding path 420 is conveyed to the folding roller 421 and is folded into a Z shape. On the other hand, when the folding process is not performed, the folding path selection flapper 410 is turned off, and the sheet is directly sent from the printer 300 to the finisher 500 via the folding conveyance horizontal path 402.

(Main part of finisher) Finisher 50
0 is a process of sequentially taking in the sheets discharged through the folding device 400, aligning the plurality of the taken-in sheets into a bundle, stapling the stapled rear end of the bundled sheet bundle, and taking in the sheets. Post-processing of each sheet such as punching for making holes near the trailing edge, sorting, non-sorting, and bookbinding is performed.

The finisher 500, as shown in FIG.
It has a pair of entrance rollers 502 for guiding the sheet discharged from the printer 300 through the folding device 400 to the inside. A sheet of finisher path 5
52, or a switching flapper 5 for guiding to the first binding path 553
51 is provided.

The sheet guided to the finisher path 552 is sent toward the buffer roller 505 via the pair of conveying rollers 503. The transport roller pair 503 and the buffer roller 505 are
It is configured to be able to rotate forward and backward.

An entrance sensor 531 is provided between the entrance roller pair 502 and the conveyance roller pair 503. In the vicinity of the upstream side of the entrance sensor 531 in the sheet conveying direction, the second bookbinding path 554 is branched from the finisher path 552. Hereinafter, this branch point is referred to as a branch A. This branch A forms a branch from the pair of inlet rollers 502 to the transport path for transporting the sheet to the pair of transport rollers 503, but the pair of transport rollers 503 reverses to move the sheet from the pair of transport rollers 503 to the side of the inlet sensor 531. When it is conveyed to, the branch has a one-way mechanism that is conveyed only to the second bookbinding path 554 side.

A punch unit 550 is provided between the conveying roller pair 503 and the buffer roller 505, and the punch unit 550 operates as necessary to punch near the rear end of the conveyed sheet.

The buffer roller 505 is a roller on which a predetermined number of sheets sent to the outer periphery of the buffer roller 505 can be laminated and wound, and each pressing roller 51 is provided on the outer periphery of the roller as necessary.
Wrapped by 2, 513, 514. Buffalo 505
The sheet wound around is conveyed in the rotation direction of the buffer roller 505.

A switching flapper 510 is provided between the pressing rollers 513 and 514.
Is arranged, and a switching flapper 511 is arranged downstream of the pressing roller 514. The switching flapper 510 is a flapper for separating the sheet wound around the buffer roller 505 from the buffer roller 505 and guiding it to the non-sort path 521 or the sorting path 522, and the switching flapper 511 buffers the sheet wound around the buffer roller 505. LA 5
A flapper for separating the sheet from 05 and to the sort path 522, or to guide the sheet wound around the buffer roller 505 to the buffer path 523 in a wound state.

Non-sort path 521 by switching flapper 510
The sheet guided to is discharged onto the sample tray 701 via the discharge roller pair 509. A discharge sensor 533 for jam detection or the like is provided in the middle of the non-sort path 521.

The sheets guided to the sort path 522 by the switching flapper 510 are stacked on an intermediate tray (hereinafter referred to as a processing tray) 630 via a pair of conveying rollers 506 and 507.
The sheets stacked in a bundle on the processing tray 630 are subjected to alignment processing, stapling processing, etc., as necessary,
The sheet is discharged onto the stack tray 700 by the discharge rollers 680a and 680b.

A stapler 601 is used for the staple processing for binding the sheets stacked in a bundle on the processing tray 630. The operation of this stapler 601 will be described later. The stack tray 700 is configured to be able to move vertically.

(Binding Section) Sheets from the first binding path 553 and the second binding path 554 are stored in the storage guide 820 by the pair of transport rollers 813, and further transported until the leading edge of the sheet contacts the movable sheet positioning member 823. To be done. A bookbinding entrance sensor 817 is arranged on the upstream side of the transport roller pair 813. Further, two pairs of staplers 818 are provided at an intermediate position of the storage guide 820, and the staplers 818 are configured to bind the center of the sheet bundle in cooperation with the anvil 819 facing them.

A folding roller pair 826 is provided at a position downstream of the stapler 818. A projecting member 825 is provided at a position facing the folding roller pair 826. By projecting the projecting member 825 toward the sheet bundle stored in the storage guide 820, the sheet bundle is pushed out by the folding roller pair 826, folded by the folding roller pair 826, and then folded sheet discharge roller 827. And is discharged to the saddle discharge tray 832. A booklet discharge sensor 830 is arranged on the downstream side of the folded sheet discharge roller 827.

When folding the sheet bundle bound by the stapler 818, the positioning member 823 is lowered by a predetermined distance so that the staple position of the sheet bundle is at the center position of the folding roller pair 826 after the stapling process is completed. .

(Insert section) The inserter 900 is provided on the top of the finisher 500, and sequentially separates the cover sheet and the sheet bundle forming the interleaf sheet stacked on the tray 901 and conveys them to the finisher path 552 or the bookbinding path 553. . Here, a special sheet is stacked on the tray 901 of the inserter 900 in a normal view seen from the operator. That is, the special sheets are stacked on the tray 901 with the surface thereof facing upward.

The special sheet on the tray 901 is conveyed by the feeding roller 902 to a separating section composed of the conveying roller 903 and the separating belt 904, and is sequentially separated one by one from the uppermost sheet and conveyed.

A pair of pulling rollers 90 is provided on the downstream side of the separating section.
5 is arranged, and the special sheet separated by the pull-out roller pair 905 is stably guided to the transport path 908. A feed sensor 907 is provided on the downstream side of the pull-out roller pair 905, and between the feed sensor 907 and the inlet roller pair 502,
A conveyance roller 906 for guiding the special sheet on the conveyance path 908 to the entrance roller pair 502 is provided.

(Finisher Block Diagram) Next, the structure of the finisher control unit 501 for driving and controlling the finisher 500 will be described with reference to FIG. FIG. 4 is a block diagram showing the configuration of the finisher controller 501 shown in FIG.

As shown in FIG. 4, the finisher control section 501 has a CPU circuit section 560 composed of a CPU 561, a ROM 562, a RAM 563 and the like. The CPU circuit unit 560 is a C provided on the image forming apparatus main body side via the communication IC 564.
Data is exchanged by communicating with the PU circuit unit 150, and various programs stored in the ROM 562 are executed based on an instruction from the CPU circuit unit 150 to control the drive of the finisher 500.

When performing this drive control, the CPU circuit section
The detection signals from various sensors are captured in 150. These various sensors include an inlet sensor 531 and a bookbinding inlet sensor 8
17, a booklet ejection sensor 830, a feeding sensor 907, and a sheet set sensor 910. The sheet set sensor 910 is a sensor for detecting whether or not a special sheet is set on the tray 901 of the inserter 900. CPU circuit section
A driver 520 is connected to the 560, and the driver 520 is a CPU
The motor and the solenoid are driven based on the signal from the circuit unit 560. The CPU circuit unit 150 also drives the clutch.

Here, as the motor, a pair of inlet rollers 50
2, a conveyance roller pair 503, an inlet motor M1 that is a drive source of the conveyance roller 906, a buffer motor M2 that is a drive source of a buffer roller 505, a conveyance roller pair 506, a discharge roller pair 507,
A discharge motor M3 that is the drive source of the discharge roller pair 509, a bundle discharge motor M4 that drives the discharge rollers 680a and 680b, a transport motor M10 that is the drive source of the transport roller pair 813, and a positioning that is the drive source of the sheet positioning member 823. Motor M1
1, a projecting member 825, a folding roller pair 826, a folding motor M12 that is a drive source of the folded sheet discharge roller pair 827, a feeding roller 902 of the inserter 900, a transport roller 903, and a separation belt 9
04, the feeding motor M that is the drive source of the pull-out roller pair 905
There are 20.

The inlet motor M1, the buffer motor M2, and the discharge motor M3 are stepping motors, and by controlling the excitation pulse rate, the roller pair driven by each motor is rotated at a constant speed or at its own speed. can do. Further, the inlet motor M1 and the buffer motor M2 can be driven by the driver 520 in the forward and reverse directions of rotation.

Conveyor motor M10, positioning motor M11
Is a stepping motor, and the folding motor M12 is D
It consists of a C motor. The transport motor M10 is configured to be able to transport the sheet in synchronization with the speed of the entrance motor M1. The feeding motor M20 is composed of a stepping motor, and is configured to be able to convey a sheet in synchronization with the speed of the entrance motor M1.

As the solenoids, a solenoid SL1 for switching the switching flapper 510, a solenoid SL2 for switching the switching flapper 511, a solenoid SL10 for switching the switching flapper 551, and a feeding shutter of the inserter 900 (not shown in FIG. 3). Solenoid SL20 for driving
There is a solenoid SL21 that drives the feeding roller 902 of the inserter 900 up and down.

As the clutch, a clutch CL1 for transmitting the drive of the folding motor M12 to the projecting member 825,
There is a clutch CL10 for transmitting the drive of the feeding motor M20 to the feeding roller 902.

(Operation Unit) Next, an example of selecting the post-processing mode using the operation unit 153 will be described with reference to FIG. FIG. 5 is a diagram showing an example of a screen regarding post-processing mode selection of the operation unit in the image forming apparatus of FIG.

The image forming apparatus has various processing modes such as non-sort, sort, staple sort (binding mode), and bookbinding mode as post-processing modes. Further, the insertion sheet is used as a slip sheet mode, and the cover sheet, the final sheet, or the middle sheet. It is set so that it can be inserted into a sheet. Setting of such a processing mode is performed by an input operation from the operation unit 153. For example, when setting the post-processing mode, the menu selection screen shown in FIG. 5A is displayed on the operation unit 153, and the processing mode is set using this menu selection screen.

Further, for example, when setting the interleaf sheet mode,
The screen shown in FIG. 5B is displayed on the insert setting operation unit 153, and the inserter 90 is used to insert the special sheet.
It is set whether to perform from 0 or the manual feeding unit 125, and FIG.
On the screen shown in (c), it is possible to set the number of sheets to be inserted. It is possible to select and set only “1” when the special sheet is fed only to the front cover, and to select and set the desired number when there are a plurality of sheets to be inserted.

(Outline of Finisher Operation) Next, regarding sheet conveyance from the inserter 900 and the printer 300 to the processing tray 630 in the finisher 500 in the sort mode, FIG.
It will be described with reference to FIGS. 6 to 11 are views for explaining the flow of sheets from the inserter and the printer to the processing tray in the finisher in the sort mode in the image forming apparatus of FIG.

When the sheet C is inserted as a cover sheet into the sheet after the image formation, the sheet is set on the tray 901 of the inserter 900 as shown in FIG. 6B. At this time, as shown in FIG. 6A, the sheet C is set so that the image surface is facing upward and the binding position is left when viewed from the operator, and is fed in the direction of the arrow in the figure. The set state of the sheet C is the same as the set state of the original in the original feeding apparatus 100, and the operability in setting the sheet C can be improved.

When the sheet C is set on the tray 901,
As shown in FIG. 7, feeding of the uppermost sheet C1 is started, and the switching flapper 551 is switched to the finisher path 552 side. The sheet C1 is guided from the conveying path 908 through the pair of entrance rollers 502 into the finisher path 552, and when the leading edge of the sheet C1 is detected by the entrance sensor 531,
Feeding of the sheet (sheet P1 shown in FIG. 8) after the image formation from the printer 300 is started.

Then, as shown in FIG.
The sheet P1 fed from the sheet is guided into the finisher 500, and the sheet C1 is guided to the sort path 522 via the buffer roller 505. At this time, the switching flapper 5
Both 10 and 511 are switched to the sort path 522 side.

Sheet C1 led to this sort path 522
Are stored on the processing tray 630 as shown in FIG. At this time, the sheet P1 from the printer 300 is guided into the finisher path 552. This sheet P1
As shown in FIG. 10, the sheet is guided to the sort path 522 via the buffer roller 505 and is conveyed toward the processing tray 630, like the sheet C1. A sheet P2 following the sheet P1 is guided into the finisher path 552.

Then, as shown in FIG. 11, the sheet P1
Are stacked and stored on the sheet C1 already stored in the processing tray 630, and the subsequent sheet P2 is stacked and stored on the sheet P1.

Here, each sheet P from the printer 300
1 and P2 have mirror-image-processed images formed thereon, and the respective sheets P1 and P2 are discharged by reversal discharge, so that the sheets P1 and P2 face the image surface downward like the sheet C1. Stapler 60
Stored in the processing tray 630 toward the 1 side. Also, this figure 1
Although not shown in FIG. 1, when there is a special sheet for the next bundle, the special sheet is fed to the transport path 908 and made to stand by while the sheets P1 and P2 forming the current bundle are being fed. Has been done. With this configuration, productivity in the sort mode processing can be improved.

(Outline of bookbinding operation) Next, image formation in the bookbinding mode will be described with reference to FIG. Figure 1
FIG. 2 is a diagram for explaining image formation in the bookbinding mode in the image forming apparatus of FIG.

When the bookbinding mode is designated, the document feeding device
The manuscript set to 100 is sequentially read from the first page, the images of the read manuscripts are sequentially stored in the hard disk, and the number of simultaneously read manuscripts is counted. When the reading of the document is completed, the read document images are classified by the following equation (1), and the image forming order and the image forming position are determined.

M = n × 4-k (1) M: Number of originals n: An integer of 1 or more, the number of sheets k: any value of 0, 1, 2, 3

Detailed description of the image forming order and image forming position control will be omitted. The image formation in the bookbinding mode will be described by taking the case where the number of read originals is eight as an example. As shown in FIG. 12A, eight pages of original image data (R1 to R8) can be read on the hard disk. They are stored in the order

The image forming order and the image forming position of each image data (R1 to R8) are determined. As a result, as shown in FIG. 12B, after the above-described mirror image processing is performed, on the first surface (front surface) of the sheet P1 of the first page, the R4 image is on the left half and the R5 image is on the right half. An image is formed, and the sheet P1 is guided to the double-sided conveyance path 124. Then, the sheet P1 is fed again to the transfer portion 116, and the second
An R6 image is formed on the left half of the surface (rear surface) and an R3 image is formed on the right half. Then, the sheet P1 on which images are formed on both sides in this way is reversed by the reverse discharge and discharged, and then sent to the bookbinding path 553 of the finisher 500.
As for the sheet P1 by this reverse ejection, as shown in FIG.
As shown in (c), the second surface on which the R6 image and the R3 image are formed is conveyed upward and the R6 image is conveyed in the direction of the arrow in the figure.

Next, the R2 image is formed on the left half and the R7 image is formed on the right half of the first surface (front surface) of the sheet P2 of the second page, and this sheet P2 is guided to the double-sided conveyance path 124. The sheet P2 is fed again to the transfer unit 116,
R8 image on the left half of the second surface (rear surface) and R1 on the right half
An image is formed. The sheet P2 is reversed and discharged, and then the first bookbinding path 553 of the finisher 500.
Sent to. As a result of this reverse ejection, as for the sheet P2, as shown in FIG. 12C, the sheet P2 is conveyed in the direction of the arrow in the drawing with the second surface on which the R8 image and the R1 image are formed facing upward and the R8 image at the top. To be done.

Each of the sheets P1 and P2 has a finisher 500.
It is guided and stored in the storage guide 820 through the bookbinding path 553. In this storage guide 820, FIG.
As shown in (d), the sheet P1 is stored on the protruding member 825 side, and the sheet P2 is stored on the folding roller pair 826 side. Also, the sheets P1 and P2
The first surface of is oriented toward the protruding member 825 and is housed.
The positioning of the sheets P1 and P2 within the storage guide 820 is performed by a positioning member 823.

(Outline of operation of bookbinding + inserter) Regarding sheet conveyance from the inserter 900 and the printer 300 in this bookbinding mode to the storage guide 820 in the finisher, FIG.
It will be described with reference to FIGS. 13 to 19
FIG. 20 is a diagram for explaining the flow of sheets from the inserter and the printer to the storage guide in the finisher in the bookbinding mode in the image forming apparatus in FIG. 1, and FIG. 20 is the bookbinding by the folding process and the binding process in the finisher in FIG. It is a figure which shows the example which does.

When the sheet C1 is inserted as a cover sheet into a sheet after image formation for bookbinding, the sheet C1 is set on the tray 901 of the inserter 900 as shown in FIG. 13B. At this time, as shown in FIG. 13A, the sheet C1 is set on the tray 901 with the image surface on which the images R and F are formed facing upward, and is fed with the image F at the top. That is, the sheet C1 is set in an emmetropic state as seen from the operator, and the set state of the sheet C1 is the same as the set state of the document in the document feeder 100. Therefore, operability when setting the sheet C1 can be improved.

When the sheet C1 is set on the tray 901, as shown in FIG. 14, the feeding of the uppermost sheet C1 is started and the switching flapper 551 causes the finisher path 552.
Switched to the side. The sheet C1 is guided from the conveying path 908 through the pair of entrance rollers 502 into the finisher path 552,
When the leading edge of the sheet C1 is detected by the entrance sensor 531, the image-formed sheet from the printer 300 (see FIG.
The feeding of the sheet P) shown in is started.

Then, as shown in FIG.
The sheet P fed from 0 is guided into the finisher 500, and the sheet C1 is guided to the non-sort path 521 side via the buffer roller 505. At this time, the switching flapper 510 is switched to the non-sort path 521 side.

Further, when the sheet C1 is guided to the non-sort path 521 side and conveyed until the rear end passes through the entrance sensor 531, the sheet C1 is temporarily stopped as shown in FIG. At this time, the sheet P from the printer 300 is
Guided into the finisher 500. Then, with the sheet C1 stopped, as shown in FIG. 16, the sheet P is guided by the switching flapper 551 to the first bookbinding path 553 and stored in the storage guide 820, and the sheet P following this sheet is the same. Then, the user is led to the first binding path 553. At this time, sheet C
The sheet C2 following 1 is separated and conveyed to a position before the conveyance roller 906, and waits until a predetermined number of sheets are stored in the storage guide 820.

When a predetermined number of sheets P are stored in the storage guide 820, as shown in FIG. 17, the sheet C1 is reversed and fed into the storage guide 820 via the branch A and the second bookbinding path 554. Be guided. At this time, the sheet C1 is
As shown in FIG. 8, the sheet is conveyed with the image R side as the leading end, and is stacked and stored on the bundle of sheets P already stored in the storage guide 820. When the sheet C1 is stored in the storage guide 820, the feeding of the sheet C2 following the sheet C1 is started. Here, for example, when the sheet C2 is an inappropriate sheet having a size different from the predetermined size, as shown in FIG. 19, the sheet C2 is discharged to the sample tray 701 without being temporarily stopped in the state shown in FIG. It

After the sheets C1 are stacked on the bundle of sheets P and stored in the storage guide 820, the sheets C1 are
The projecting member 825 is projected with respect to the stack of sheets P, and this stack is pushed toward the folding roller pair 826. The bundle is folded by the folding roller pair 826 at the central portion (image boundary portion of the image surface) of the bundle and discharged to the saddle discharge tray 832.

In the state of being folded in this way,
As shown in FIG. 20B, the image F of the sheet C1 is arranged on the cover page, the image R is arranged on the last page, and the images of the respective sheets P are arranged in the page order, and the sheet C1 and the sheet P are arranged. The orientations of the images are matched.

In this way, by the feeding control of the sheet C1 from the inserter 900 and the conveyance control of the sheet P from the printer 300, the image R of the sheet C1 is the cover page and the image R is the last page in the bookbinding state. Since the images of the respective sheets P are arranged in the page order and the orientations of the images are matched, it is possible to form the sheets P without losing the printing quality of the special sheet from the inserter 900 and the sheet conveyance durability of the printer 300. It can be combined with a special sheet for bookbinding. Also, in this sort mode, the finisher 50
Insert the special sheet with 0 to finisher pass 55
2 is made to stand by, then the sheet is guided into the storage guide 820 and stored, and after the storage of this sheet, the finisher path 552
Since the special sheet waiting inside is guided into the storage guide 820 and is stored therein, it is possible to improve the productivity when the sheet and the special sheet are combined into a book.

If necessary, in the state where the sheets C1 are stacked and stored in the stacking guide 820 on the stack of sheets P, the stacker 818 can bind the stack at the central portion.

An embodiment of the double feed detection method in the interposer process in the slip sheet mode of the present invention will be described.
FIG. 21 is a sectional view of the interposer 240a of the present invention. On the upstream side of the interposer 240a, a sheet bundle 250 serving as a cover sheet or a slip sheet is stacked in the order in which it is used in the manual feeding unit 125. When the interleaf sheet is fed from the sheet bundle 250, the pickup roller 252 waiting above the sheet bundle 250 is lowered to a position 252 ′ by a solenoid (not shown) to feed the top interleaf sheet. Will be

The fed interleaving paper is separated one by one by the conveying roller 253 and the separating roller 254 located downstream thereof, and is conveyed to the conveying roller pair located further downstream, and then further downstream. Not transported to the finisher and subjected to processing such as stapling. Here, the fed interleaf paper is irradiated with the light of the light source 256 while passing through the conveyance path, the reflected light is condensed by the lens 257, and the image is read by an image reading device such as a charge coupled device 258 (CCD). The front side image is read. The image thus read is stored as image data in a memory (not shown).

Besides, an example of an embodiment in which image information is read by a contact sensor will be described with reference to FIG. Figure 2
2 is a sectional view of an interposer 240b of the present invention using a contact sensor. A sheet bundle 250 serving as a cover sheet or a slip sheet is stacked in the order in which it is used in the manual feed unit 125.

Sheet bundle 250 in interposer 240b
When the interleaf sheet is fed from the above, the topmost interleaf sheet is fed by the pickup roller 252 waiting above the sheet bundle 250 being lowered to the position of 252 ′ by the solenoid (not shown). Become. The fed interleaving paper is separated one by one by a conveying roller 253 and a separating roller 254 located downstream thereof, and is conveyed to a conveying roller pair located further downstream, and then to a finisher (not shown) further downstream. It will be conveyed and subjected to processing such as stapling.

Here, the fed interleaving paper is urged by the contact sensor 260 by the pressure roller 259 while passing through the conveying path, so that the image information on the surface can be read. The image thus read is stored as image data in a memory (not shown).

In this embodiment, the method of reading the image information by the charge coupled device (CCD) and the contact sensor has been described. However, the image reading device is not limited to these, and the image information can be read. Any device capable of performing the above can be used as the double feed detecting means of the present invention.

FIG. 23 shows a model diagram of a sheet bundle fed as a slip sheet. In this model, the cover for one bundle,
Or four sheets of interleaving paper are used. As described above, the image information is set to P1 every time the first slip sheet is fed.
It will be read in the order of ~ P4. Next, when the second set of sheets is fed in the order of P1 to P4, the first set of P
The image information of 1 and the image information of P1 of the second copy are compared to determine whether or not the sheets are double-fed.

If no double feed occurs, P2 of the first copy
Image information of P2 of the second copy, image information of P3 of the first copy, and image information of P3 of the second copy are sequentially compared, that is, double feed detection is performed. become.
In the model diagram of FIG. 23, since the image information of P2 is read in the portion P1 of the fifth copy, double feeding is detected and the subsequent job is stopped.

In the present embodiment, the double feed detection method based on the image information on one side has been described. However, in order to improve the precision of the double feed detection based on the image information, it is possible to read not only the lower surface of the paper but also the image on the upper surface. It is also possible to have a different configuration. Further, in the above-mentioned embodiment, only the image information of the sheet is read, but the image information is not the only information to be read. For example, when a sheet such as a tab sheet is used as the interleaf sheet, the outline of the sheet is read. By making it possible to obtain information, that is, tab position information, it can be used as a means for detecting double feed.

FIG. 24 shows an example of image information read to detect double feeding. In the upper left of this figure, a diagram is shown in which the mesh to be read is cut for each pixel. As for the image information of pixels used for reading or double feed detection, there is no problem even if all the pixel information is used, but if the number of interleaf sheets used for one bundle is large, the image information is stored. It requires a huge amount of memory to store the data, which increases costs. Therefore, as shown in FIG. 24, there is no problem even if a method is adopted in which image information is read for each certain fixed pixel (pixels used for image determination in the drawing) and double feeding is compared.

By performing such processing, it is possible to shorten the double feed detection time based on the image information at the same time. Pixel information used for double-feed detection for each sheet (referred to as effective pixels here) does not need to be fixed to a certain number in particular, for example, when the number of interleaf sheets in one bundle is small. A memory for storing image information by changing the setting of the effective pixel number so that the effective pixel number can be set small when the number of interleaving sheets in one bundle is large. Can be used effectively.

As described above, according to the present invention, by detecting the image information of the fed sheets and comparing this with the image information of the sheets fed in the past, the double feeding can be surely detected. You can do it. It is not necessary to write a mark such as a code on the sheet to detect double feeding, and the quality of the output sheet is not impaired.

Further, it is possible to detect double feeding without being affected by variations in sheets such as sheet size and thickness. In addition, even if there is a problem with the image information transferred to the sheet, it is possible to reduce the time, power, man-hours, etc. without generating a defective output paper by determining the double feeding.

(Other Embodiments) In the above-described embodiment, the interposer 240 (240a, 240a) is provided in the manual feeding unit 125.
Although the sheet processing apparatus has been described by exemplifying the case of arranging b), the invention is not limited to this.
You may arrange in other parts, such as 900.

[0103]

As described above, in the present invention, sheet stacking means for stacking a plurality of sheets, sheet separating means for separating the plurality of sheets on the sheet stacking means one by one, and the sheet separating means. An image reading unit that reads the image information of the sheet sent by the unit, sequentially stores the image information read by the image reading unit, and compares the stored image information with the image information of the sheet to be newly read. Thus, since the double feeding of the sheet is detected, the double feeding of the sheet can be prevented without measuring the thickness of the sheet.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing the main configuration of an image forming apparatus of the present invention.

FIG. 2 is a block diagram illustrating a configuration of a controller that controls the entire image forming apparatus.

FIG. 3 is a diagram showing configurations of a folding device 400 and a finisher 500.

FIG. 4 is a block diagram showing a configuration of a finisher controller 501.

FIG. 5 is a diagram showing an example of a screen regarding post-processing mode selection of an operation unit in the image forming apparatus.

FIG. 6 is a diagram illustrating a flow of sheets from an inserter and a printer to a processing tray in a finisher in a sort mode in the image forming apparatus.

FIG. 7 is a diagram illustrating a flow of sheets from an inserter and a printer to a processing tray in a finisher in a sort mode in the image forming apparatus.

FIG. 8 is a diagram for explaining the flow of sheets from the inserter and the printer to the processing tray in the finisher in the sort mode in the image forming apparatus.

FIG. 9 is a diagram for explaining the flow of sheets from the inserter and the printer to the processing tray in the finisher in the sort mode in the image forming apparatus.

FIG. 10 is a diagram for explaining the flow of sheets from the inserter and the printer to the processing tray in the finisher in the sort mode in the image forming apparatus.

FIG. 11 is a diagram for explaining the flow of sheets from the inserter and the printer to the processing tray in the finisher in the sort mode in the image forming apparatus.

FIG. 12 is a diagram for explaining image formation in the bookbinding mode in the image forming apparatus.

FIG. 13 is a diagram for explaining the flow of sheets from the inserter and the printer to the storage guide in the finisher in the bookbinding mode in the image forming apparatus.

FIG. 14 is a diagram illustrating a flow of sheets from an inserter and a printer to a storage guide in a finisher in a bookbinding mode in the image forming apparatus.

FIG. 15 is a diagram for explaining the flow of sheets from the inserter and printer to the storage guide in the finisher in the bookbinding mode in the image forming apparatus.

FIG. 16 is a diagram for explaining the flow of sheets from the inserter and the printer to the storage guide in the finisher in the bookbinding mode in the image forming apparatus.

FIG. 17 is a diagram illustrating a flow of sheets from the inserter and the printer to the storage guide in the finisher in the bookbinding mode in the image forming apparatus.

FIG. 18 is a diagram illustrating a flow of sheets from the inserter and the printer to the storage guide in the finisher in the bookbinding mode in the image forming apparatus.

FIG. 19 is a diagram illustrating a flow of sheets from the inserter and the printer to the storage guide in the finisher in the bookbinding mode in the image forming apparatus.

FIG. 20 is a diagram showing an example of bookbinding by folding processing and binding processing in the finisher.

FIG. 21 is a sectional view of an interposer.

FIG. 22 is a sectional view of an interposer of the present invention using a contact sensor.

FIG. 23 is a model diagram of a sheet bundle fed as a slip sheet.

FIG. 24 is a diagram showing an example of image information read to detect double feeding.

[Explanation of symbols]

A ... Branch C1 ... Sheet C2 ... Sheet CL1 ... Clutch CL10 ... Clutch M1 ... Inlet motor M10 ... Conveyor motor M11 ... Positioning motor M12 ... Motor M2 ... Buffer motor M20 ... Feed motor M3 ... Discharge motor M4 ... Bundle discharge motor P1 ... Sheet P2 ... Sheet SL1 ... Solenoid SL10 ... Solenoid SL2 ... Solenoid SL20 ... Solenoid SL21 ... Solenoid 10… Image forming device body 100… Document feeder 101 ... Document feeder control unit 102… Platen glass 104… Scanner unit 108… Lens 109… Image sensor 110… Exposure controller 110a ... Polygon mirror 111… Photosensitive drum 112… Ejection tray 113 ... Developer 114… Cassette 115… Cassette 116… Transfer unit 117… Fixing unit 118… Ejection roller 121 ... flapper 122… Inversion path 124… Double-sided transport path 125… Manual feed unit 150 ... CPU circuit 151 ROM 152… RAM 153… Operation part 200… Image reader 201… Image reader controller 202… Image signal controller 209… External I / F 210… Computer 240a ... Interposer 240b ... Interposer 252 ... Pickup roller 253… Conveyor rollers 254… Separation roller 255… Conveyor roller pair 256… Light source 257… Lens 258… Charge coupled device 259 ... Pressure roller 260… Contact sensor 300… Printer 301… Printer controller 400… Folding device 401 ... Device control unit 402… Folding transport horizontal path 403… Conveyor roller pair 404 ... Conveying roller pair 410… Flap path selection flapper 420… fold path 421 Folding roller 500 ... Finisher 501… Finisher controller 502… Inlet roller pair 503 ... Conveyor roller pair 505 ... Buffalo 506… Conveyor roller pair 507 ... Ejection roller pair 509… Ejection roller pair 510… Switching flapper 511 ... Switching flapper 512 ... Pressing roller 513 ... Pressed roller 514 ... Pressed roller 520 ... driver 521… Non-sorted path 522… Sort path 523… Buffer pass 531… Inlet sensor 533… Emission sensor 550 ... Punch unit 551 ... Switching flapper 552 ... Finisher pass 553… First binding pass 554… Second binding pass 560 ... CPU circuit section 561 ... CPU 562 ... ROM 563 ... RAM 564 ... Communication IC 601 ... Stapler 630… Processing tray 680a ... Ejection roller 680b ... Ejection roller 700… Stack tray 701… Sample tray 813… Conveyor roller pair 817… Booklet entrance sensor 818… Stapler 819… Anvil 820… Storage guide 823… Positioning member 825… Projection member 826… Folding roller pair 827 Folded sheet discharge roller pair 830… Booklet ejection sensor 832… Saddle discharge tray 900 ... Inserter 901 ... Tray 902 ... Feeding roller 903… Conveyor roller 904… Separation belt 905… Pull-out roller pair 906… Conveyor roller 907… Feed sensor 908 ... Transport path 910… Sheet set sensor

Claims (5)

[Claims] 1. A sheet stacking unit for stacking a plurality of sheets, a sheet separating unit for separating the plurality of sheets on the sheet stacking unit one by one, and image information of the sheets sent by the sheet separating unit. An image reading unit for reading is provided, the image information read by the image reading unit is sequentially stored, and the double feeding of the sheets is detected by comparing the stored image information with the image information of the sheet to be newly read. A sheet processing apparatus characterized by the above. 2. The sheet processing apparatus according to claim 1, wherein when the stored image information is compared with the image information of a sheet to be newly read, the image information is compared by using a part of the stored image information. A sheet processing apparatus characterized by performing. 3. The sheet processing apparatus according to claim 1, wherein the image reading unit has a charge coupled device (CCD) for reading image information. 4. The sheet processing apparatus according to claim 1, wherein the image reading unit has a contact sensor that reads image information. 5. An image forming unit for forming an image on an image carrier, a sheet processing apparatus for feeding and processing a sheet,
An image forming apparatus having the sheet processing apparatus according to claim 1, wherein the sheet processing apparatus is the sheet processing apparatus according to claim 1.