JPH0940277A - Sheet storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the growth of curls of sheets so as to make sheet stitching treatment desirable by controlling the spacing of trays prior to stitching treatment to sheets on the trays. SOLUTION: Sheets discharged from an image forming device are conveyed and stored in a plurality of trays. The positions of a plurality of trays are moved to store the sheets, and a space between the tray in storing action and an adjacent tray is enlarged. Further before stitching treatment, it is so controlled as to enlarge the spacing of the trays without sheets stored while narrowing the spacing of the trays with sheets stored to press the sheets on the tray and then to enlarge the spacing of the trays with the sheets stored.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet storage device having a plurality of trays for storing sheets.

[0002]

2. Description of the Related Art Conventionally, as a sheet storage device for storing sheets discharged from an image forming apparatus, an image is stored in a bin moving type sorter having a plurality of movable bins, or in a plurality of fixed bins. There is a bottle-fixed sorter that sorts the sheets after they are formed. There is also a sorter with a built-in stapler for stapling the sheets in the bottle.

[0003]

However, when the image forming apparatus equipped with the sorter as described above is a color copying machine, for example, there are the following problems.

That is, generally, an image such as a photograph is often used as an original to be copied by a color copying machine, and the surface of the sheet after passing through the fixing device after the image is transferred,
The toner is fixed on the entire surface of the sheet.
The thermally expanded toner immediately after the fixing is cooled with the passage of time, the toner is stored on the sheet, and the sheet is greatly curled. As the sheet cools, the amount of curl increases. When stapling is performed on the curled sheet in this way, the stapler may not be able to bite the sheet well, and the stapling may fail.

[0005]

In order to solve the above-mentioned problems, the present invention provides a conveying means for conveying a sheet discharged from an image forming apparatus, and a plurality of trays for accommodating the sheet conveyed by the conveying means. And tray moving means for moving the positions of the plurality of trays with respect to the conveying means and for increasing the distance between the tray to be stored and an adjacent tray so as to store a sheet in each of the plurality of trays, and the tray. Before the binding process is performed on the upper sheet and the binding process is performed by the binding process means, the gap between the trays in which the sheets are not stored is widened and the trays in which the sheets are stored are narrowed. ,
A sheet storage device comprising: a control unit configured to press a sheet on a tray and then control the tray moving unit so as to widen a space between the trays storing the sheets.

[0006]

FIG. 1 is a schematic sectional view of a color image forming apparatus as an embodiment of the present invention.

In this example, a digital color image reader unit 201 (hereinafter abbreviated as "reader unit") is provided in an upper portion, a digital color image printer unit 202 (hereinafter abbreviated as "printer unit") in a lower portion, a reader unit 201 and a printer. An image processing unit 203 is provided between the units 202.

In the reader unit 201, the original 30 is placed on the original table glass 31 and is exposed and scanned by the exposure lamp 32.
3, the light is condensed on the full-color sensor 34 integrally formed with the RGB three-color separation filter, and a color-separated image analog signal is obtained. The color-separated image analog signal is digitized through an amplifier circuit (not shown), processed by the image processing unit 203, and then sent to the printer unit 202.

In the printer unit 202, the photosensitive drum 1 as an image bearing member is rotatably supported in the direction of the arrow, and a pre-exposure lamp 11, a corona charger 2 and a laser exposure optical system 3 are provided around the photosensitive drum 1. The potential sensor 12, the developing device 4 (developing devices 4y, 4c, 4m, 4Bk), the on-drum light amount detection sensor 13, the transfer device 5, and the cleaning device 6 are arranged.

In the laser exposure optical system 3, the reader unit 2
The image signal from 01 is converted into an optical signal by a laser output section (not shown), the converted laser light is reflected by the polygon mirror 3a, passes through the lens 3b and the mirror 3c,
The image is projected on the surface of the photosensitive drum 1.

During image formation by the printer unit 202,
Rotate the photosensitive drum 1 in the direction of the arrow to move the pre-exposure lamp 11
The photosensitive drum 1 after the charge is removed in step 1 is uniformly charged by the charger 2, and then a light image E is emitted for each separated color to form a latent image.

Next, a predetermined developing device is operated to develop the latent image on the photosensitive drum 1, and a toner image based on resin is formed on the photosensitive drum 1. The developing device is an eccentric cam 2
By the operations of 4y, 24c, 24m, and 24Bk, the photosensitive drum 1 is selectively approached in accordance with each separated color.

The developed toner image on the photosensitive drum 1 is recorded on the recording material cassettes 7a, 7b, 7c and the intermediate tray 22.
Alternatively, the image is transferred from the recording material tray 7m to the recording material supplied to the position facing the photosensitive drum 1 via the transport system and the transfer device 5. The transfer device 5 of this example includes a transfer roller 5a serving as a recording material holding unit, a transfer charging device 5b, and a suction roller 5 facing a suction charging device 5c for electrostatically sucking a recording material.
g, an inner charging device 5d, and an outer charging device 5e, and a recording material carrying sheet 5f made of a dielectric material is cylindrically integrated in the peripheral opening area of the transfer drum 5a that is rotatably supported. It has been stretched. A dielectric sheet such as a polycarbonate film is used as the recording material carrying sheet 5f (hereinafter referred to as "transfer sheet 5f").

In this embodiment, since electrostatic attraction is used as the recording material carrying means, 1/2 of the entire circumference of the transfer sheet 5f is used.
In the case of the following recording materials (250 mm), images can be formed on two recording materials at the same time. The case of simultaneously forming images on these two recording sheets is referred to as "two-sheet attachment control", and the case of performing image formation by electrostatically attracting one recording material to the transfer sheet 5f is referred to as "one-sheet attachment control". ".

As the drum-shaped transfer device, that is, the transfer drum 5a is rotated, the toner image on the photosensitive drum 1 is transferred onto the recording material carried on the transfer sheet 5f by the transfer charger 5b. In this way, the transfer sheet 5
A desired number of color images are transferred to the recording material that is adsorbed and conveyed to f, and a full-color image is formed. In the case of forming a full-color image, the recording material on which the four color toner images have been transferred in this way is separated from the transfer sheet 5f from the transfer drum 5a by the action of the separation claw 8a, the separation push-up roller 8b and the separation charger 5h. After being subjected to curl correction control by a paper ejection curl correction unit 500, which will be described later, via the heat roller fixing device 9, the paper is sent to a paper ejection post-processing unit (sorter) 400 and subjected to desired post-processing such as collation and stapling. It

On the other hand, after the transfer, the photosensitive drum 1 is subjected to the image forming step again after the residual toner on the surface is cleaned by the cleaning device 6.

When images are formed on both sides of the recording material,
After the recording material having an image formed on one surface is discharged from the fixing device 9, the transport path switching guide 19 is immediately driven to guide the recording material through the transport vertical path 20 and then to the reversing path 21a. By the reverse rotation of the reversing roller 21b, the rear end of the fed-in roller is ejected in the direction opposite to the fed-in direction, and the trailing end is stored in the intermediate tray 22. Thereafter, an image is formed on the other surface again by the above-described image forming step. When images are formed on both the front and back sides of the recording material in this way, the first side of the recording material on which the image is first formed is the “first side of both sides”, and the second surface on which the image is formed is the “second side”. Both sides are second side. "

Further, in order to prevent scattering and adhesion of powder on the recording material carrying sheet 5f of the transfer drum 5a and adhesion of oil described later on the recording material, a fur brush facing the recording material carrying sheet 5f. 14 and a fur backup brush 15, an oil cleaning roller 16 and an oil cleaning backup brush 17 which face each other via the recording material carrying sheet 5f, and a polishing roller 18 and a polishing roller backup brush 19 which face each other via the recording material carrying sheet 5f. Use to clean. Such cleaning is performed before or after image formation, and at any time when a jam (paper jam) occurs.

Further, in this example, the eccentric cam 25 is operated at a desired timing and the cam follower 5i integrated with the transfer drum 5a is operated, so that the gap between the recording material carrying sheet 5f and the photosensitive drum 1 is reduced. It has a configuration that can be set arbitrarily. For example, during standby or when the power is off, the interval between the transfer drum 5a and the photosensitive drum 1 is increased.

Next, the toner density control in the developing device 4 will be described. Since each toner in the magenta developing device 4m, the cyan developing device 4c, and the yellow developing device 4y reflects near-infrared light having a wavelength of about 960 nm, its characteristics are used to develop the inside of each developing device. The reflected light is detected by the developer concentration detecting unit 780 (see FIG. 2) arranged in the printer, converted into a toner concentration signal by the A / D converter 752 (see FIG. 2), and the toner corresponding to the toner concentration signal is not shown. Replenish the developer from the hopper.

On the other hand, the black toner has a wavelength of about 96.
Since the near-infrared light of 0 nm is absorbed, the toner density is not detected in the black developing device 4Bk, and the photosensitive drum 1 is not detected.
Wavelength of about 960 for black toner image developed on
The developed black toner density is detected from the ratio of the reflection component on the surface of the photosensitive drum 1 and the absorption component by the black toner by irradiating the near infrared light of nm, and the toner density in the developing device is calculated from this.

The on-drum light amount detection sensor 13 is arranged between the black developing device 4Bk and the transfer charging device 5b, and has a structure capable of detecting the black toner image developed by the black developing device 4Bk before the transfer. It can be detected in a state where there is no toner density fluctuation due to the operation.

Next, the heat roller fixing device 9 will be described in detail. The heat roller fixing device 9 has an upper fixing roller 9a, a lower fixing roller 9b, a fixing web 9c, and a fixing oil coating 9d.

The heat roller fixing device 9 includes the fixing rollers 9a and 9a.
The toner on the recording material is melted by the heat energy of b,
The toner melted by the pressure between the fixing rollers 9a and 9b is fixed to the recording material. The surfaces of the upper fixing roller 9a and the lower fixing roller 9b are the upper fixing heater 9e and the lower fixing heater 9f which are built into the substantially central portions thereof, and the upper fixing thermistor 781 and the lower fixing thermistor which detect the respective roller surface temperatures. And 782 independently control the surface temperature.

The fixing web 9c contacts the upper fixing roller 9a when necessary to remove dirt on the upper fixing roller 9a or offset toner. At this time, the take-up device incorporated in the fixing web 9c can bring the new surface of the fixing web 9c into contact with the upper fixing roller 9a to improve the cleaning performance. Further, a fixing oil application roller 9 for supplying silicone oil to the surface of the cleaned upper fixing roller 9a.
d is prepared, and silicone oil is applied to the upper fixing roller 9a when necessary so that the toner on the recording material does not adhere to the upper fixing roller 9a.

Further, the heat roller fixing device 9 drives the fixing rollers 9a and 9b and the recording material conveying portion 9g by a fixing drive motor (not shown in FIG. 1). The fixing drive motor is driven by a fixing drive motor driver 761 (see FIG. 2). In this embodiment, in order to eliminate the difference in fixing property depending on the type of recording material, the fixing speed corresponding to four types of recording materials can be realized.

Assuming that the specific peripheral speed of the photosensitive drum 1 during image formation is VP (hereinafter referred to as "process speed"), the plain paper fixing speed VFN = VP, and the fixing speed VFD for the second side of the both surfaces is VFN. It is smaller, the fixing speed VFT for thick paper is smaller than VFD, and the fixing speed VFO for OHP is smaller than VFT. Therefore, VP
= VFN>VFD>VFT> VFO, and the fixing drive motor driver 761 (see FIG. 2) is configured to realize these four types of fixing speeds. The conveying speed of the recording material conveying portion 9g is set to the fixing roller 9
The peripheral speeds of a and 9b are set to be the same. Further, the fixing speed VFD for two-sided and two-sided is used for the two-sided and two-sided fixing of the toner of two or more colors, and is not used in the single-color mode in which only the one-colored toner is fixed even for the two-sided second side. The fixing operation is performed at the fixing speed VFN.

Next, the curl correction unit 500 will be described. It is known that the paper curls when the toner image formed by the electrophotographic method is fixed on the paper. It is also well known that this curl adversely affects the alignment quality when performing post-ejection processing. Therefore, in the present embodiment, the curl correction unit 500 corrects the curl, and the paper discharge post-processing unit 40
The paper is post-processed so that 0 is not adversely affected.

FIG. 22 is a curl correction unit 50 shown in FIG.
0 shows the main part. In FIG. 22, a curl portion 501 is a soft large-diameter upper roller 502 and a metallic small-diameter lower roller 50 made of an elastic material such as silicon sponge.
3.

The metal lower roller 503 is replaced by the elastic upper roller 502.
By pressing against, a convex nip is formed along the outer diameter of the metal lower roller 503, and the positive curl (convex downward) of the paper P passing through the nip is corrected.

The curl correction ability can be adjusted by changing the intrusion amount x of the metal lower roller 503 with respect to the elastic upper roller 502, and the change of the intrusion amount x can be changed by the metal lower roller 5.
The pressing arm 504 supporting 03 is pivoted about the support shaft 505 by the rotation of the eccentric cam 506. To rotate the eccentric cam 506, an eccentric cam motor 507 including a stepping motor or the like is driven.

B. RDF (recycling automatic document feeder)
(600) As shown in detail in FIG. 25, the RDF 600 includes a stacking tray 6 as a first document tray on which a document stack S is set.
Equipped with 10. The stacking tray 610 is equipped with a feeding unit 300 that constitutes one part of the document feeding unit. This feeding means includes a half-moon roller 631, a separation conveyance roller 632, a separation motor SPRMTR (not shown), a registration roller 635, and a whole belt 636.
A belt motor BELTMTR (not shown), a large conveyance roller 637, a conveyance motor FEEDMTR (not shown), a paper discharge roller 640, a flapper 641, a recycle lever 642, a paper feed sensor ENTS, and a reverse sensor TRNS. , A discharge sensor EJTS (not shown) and the like.

Here, the half-moon roller 631 and the separation / conveyance roller 632 are rotated by the separation motor SPRMTR to separate the originals one by one from the lowermost portion of the sheet S on the stack tray 610.

The registration roller 635 and the entire surface belt 636 rotate the original separated by the belt motor BELTMTR to the exposure position (sheet path c) on the original table glass 101 via the sheet paths a and b. Transport. The conveyance large roller 637 is rotated by the conveyance motor FEEDMTR to move the document on the platen glass 31 to the sheet path c.
To the sheet path e. The document conveyed to the sheet path e is returned onto the document stack S of the stacking tray 610 by the discharge roller 640.

The recycle lever 642 detects one circulation of the original document. When the original document feeding is started, the recycle lever 642 is placed on the upper part of the original document stack S, and the original documents are sequentially fed.
When the trailing edge of the final document falls through the recycle lever 642, it falls due to its own weight to detect the circulation of the document.

In the above-mentioned feeding means 630, when a double-sided original is used,
The original is once guided from the sheet paths a, b to c, then the conveyance large roller 637 is rotated, the flapper 641 is switched to guide the leading edge of the original to the sheet path d, and then the registration roller 635 passes the sheet path b. The original is inverted by being conveyed by the rear entire surface belt 636 onto the original table glass 31 and stopped. That is, the original is reversed on the sheet paths c to d and b.

The originals of the original bundle S are passed through the sheet paths a to b to c to d one by one, and the recycle lever 64 is used.
By transporting the document until it is detected that one cycle has been performed by 2, the number of documents can be counted.

C. Sheet processing device (sorter) (40
0) Next, the sorter unit will be described with reference to FIGS. In both figures, the sorter unit 400 is composed of a machine body 402 and a bin unit 403. The machine body 402 is provided with a carry-in roller pair 405 near the carry-in entrance 404. A flapper 409 for switching the sheet conveyance direction to the conveyance path 406 or 407 is disposed downstream of the carry-in roller pair 405. One of the transport paths 406 extends in a substantially horizontal direction, and the transport roller pair 408 is disposed downstream thereof, while the other transport path 406 extends in the downward direction and the transport roller pair 411 is disposed downstream thereof. Has been set up,
Further, a stapler 412 is provided at a position near the roller pair 411.
(A, 412b) are provided.

A pair of carry-in rollers 405 and a pair of carry rollers 40
8, 411 are driven by a conveyance motor 413 (not shown). The transport path 406 has a non-sort path sensor S401 for detecting the passage of a sheet, and the transport path 407 has a sort path sensor S402. Further, a bin unit 403 having a large number of bins B is arranged on the downstream side of the pair of transport rollers 408 and 411. One end of the bin unit 403 is engaged with a hook of the bin unit 403 and the other end is attached to the machine body 402. By holding the weight with a fixed spring, the bin unit 403 is supported so as to be able to move up and down.

Guide rollers 417 and 419 are rotatably supported on the upper and lower portions of the base side of the bin unit 403, and the guide rollers 417 and 419 are the above-mentioned machine body 4
02 is provided with a guide groove 402 extending vertically.
It is configured to roll inside and guide the bin unit 403. Further, the shift motor 4
21 are provided. A lead cam 423 is fixed to a rotary shaft 422 pivotally supported by the machine body 402. A chain 426 is stretched around the output shaft of the shift motor 421, whereby the rotation of the motor 421 is transmitted to the rotary shaft 422 via the chain 426.

Further, the bottle unit 403 is supported by a bottom frame 427 composed of an inclined portion and a vertical portion, and a pair of frames 429 and 429 vertically provided on the front side and the rear side of the bottom frame 427. Unit body 43 constituted by the covered cover 430
One. On the front side of the unit main body 431, a reference plate capable of abutting against the sheet S and aligning it is provided.

Although not shown, a lower arm that is rotated by a matching motor a is rotatably supported on the inner side of the base end of the bottom frame 427. Further cover 43
The upper arm a is fixed to a shaft rotatably supported by the cover 430 at a position facing the lower arm a of 0, and the rotation center of the upper arm a and the rotation of the lower arm a. A shaft a is installed at the center. A matching rod 439a is installed between the tip of the lower arm a and the tip of the upper arm a, and the aligning rod 439a is configured to be rotated by an aligning motor. Is adapted to match the front side.

Similarly, although not shown, a lower arm b which is rotated by an alignment motor b is rotatably supported on the front side of the bottom frame 427 at the base end. Further, the upper arm b is placed at a position facing the lower arm b of the cover 430.
Is fixed to a shaft b rotatably supported by the cover 430. The tip of the lower arm b and the upper arm b
An alignment rod 439b is installed on the tip of the alignment rod 439b. The alignment rod 439b is configured to rotate by an alignment motor, and aligns the sheet S on the bin B to the back side. .

The alignment motors a and b are stepping motors, and the positions of the alignment rods 439a and 439b can be accurately controlled by the number of pulses given to the stepping motor.
Further, reference numerals S403a and S403b (not shown)
A matching rod home sensor for detecting the positions of the matching rods 439a and 439b. The positions of the matching rods 439a and 439b can be controlled by the number of pulses given to the matching rod home sensor and the matching motors a and b.

The bin B has engagement plates formed on the front side and the back side thereof, respectively.
By engaging with a support plate provided on the inner side of 9, the bottle B is supported at the tip side. Further, in the bin B, a long hole 443a which is longer than the rotation distance of the alignment rod 439a at a predetermined distance from the axis a and is sufficiently wider than the width of the alignment rod 439a, and the rotation of the alignment rod 439b at a predetermined distance from the axis b. A long hole 443b that is longer than the distance and is sufficiently wider than the alignment rod 439b is provided. The base end portion Ba of the bottle stands upright with respect to the sheet storage surface Bb. The bin B is inclined at a predetermined angle upward with respect to the body 402, and the sheet S slides on the sheet storage surface Bb and abuts on the rear end with the base end Ba to be aligned in the front-rear direction. It has become so.

The bin B is provided with a notch at the portion where the stapler 412 enters so that it does not interfere with the stapler 412. The alignment rod 439a is inserted into the long holes 443a of the bins B1, B2 ... And the alignment rod 439a rotates in the long holes 443a.
The sheet S on the bin B is configured to be aligned on the front side. Similarly, the alignment rod 439b is fitted in the long holes 443b of the bins B1, B2 ...
9b rotates in the long hole 443b to move the sheet S on the bin B.
Is configured to be aligned on the back side.

The lead cam 423 engages with a part of the bin, and the rotation of the lead cam 423 causes the bin unit to move up and down along the groove 423a. It should be noted that one rotation of the lead cam 423 results in the lead cam 42
3 is detected by a lead cam sensor S404 arranged near the position 3. The position of the bin unit 403 is detected by the bin home position sensor S405.

The presence of the sheet S on the sort bin B can be detected by a sort tray sheet presence / absence detecting sensor (sheet post-processing position selecting means) S407.

An electric stapler 4 for binding the sheets S stored in the bin B is provided near the lower paper discharge roller pair 411.
12 is disposed so as to be able to move forward and backward by a drive means at a position orthogonal to the sheet S carrying-in direction, and is normally retracted to the position B so as not to interfere with the vertical movement of the bin B.
When binding the bundle of sheets S on the upper side, the stack of sheets S is moved to the position B to bind the bundle of sheets S. After completion of the binding, the electric stapler returns to the position A by a driving unit (not shown).

The electric stapler 412 performs a stapling operation by the rotation of a motor (not shown), and when binding the sheets S of a plurality of bins B ... After the stapling operation of the sheets S of one bin B is completed, the bin unit 403 is operated. The sheet S stored in the bin B is moved to a predetermined bin position to be bound.

It should be noted that S406 is a manual stapling key, which is a manual stapling key S after completion of sorting.
When 406 is pressed, a stapling operation is performed.

In addition, a matching rod 439 on the back side of the sorter 400.
The position of the sheet bundle on the bin can be pushed out by the rotation operation of a.

FIG. 2 is a block diagram of a control system in the color image forming apparatus of one embodiment of the present invention. The color image forming apparatus is roughly divided into two blocks for control purposes. One is mainly the reader unit 201 and the image processing unit 2.
03 is a reader controller 700, and the other one is a printer controller 701 that controls the printer unit 202.

Reference numeral 702 denotes the scanning mirrors 32a, 32b, 3
2c, an optical motor driver for driving an optical motor (not shown) for moving the exposure lamp 32, 703, an RDF controller for controlling an automatic document feeder RDF600 for automatically exchanging documents, and 900 for a color image An operation unit for setting the operation mode of the forming apparatus, 705 is an R storing the control program of the reader controller 700.
OM and 706 are RAs for storing data such as control values
M and 707 are I / Os for driving loads such as the exposure lamp 32. The RAM 706 is backed up by a battery so that the data can be retained even when the power is turned off.

Next, the peripheral control section of the printer controller 701 will be described. Reference numeral 750 is a ROM that stores a control program for the printer controller 701, 751 is a RAM that stores data such as control values, and 752 is a digital signal that converts analog signals from the potential sensor 12, the drum light amount detection sensor 13, and the like. An A / D converter, 753 is a D / A converter that outputs an analog set value to the high voltage controller 770 and the like, and 754 is an I / O that drives a load such as a motor and a clutch.

G. RDF Control Unit (900) FIG. 28 is a block diagram showing the circuit configuration of the RDF control unit 900. This device is a central processing unit (CPU)
901, read only memory (ROM) 902, random access memory (RAM) 903, output port 90
4, a control device 900 including an input port 905 and the like is provided, and a control program is stored in the ROM 902,
Input data and work data are stored in the RAM 903. Further, the output port 904 is connected to various motors such as the above-described separation motor and solenoid driving means, and the input port 905 is connected to a paper feed sensor or the like.
1 controls each unit connected via a bus according to a control program stored in the ROM 902. Also, CPU
901 has a serial interface function,
Serial communication is performed with the CPU of the reader control unit 700, and control data is exchanged with the reader control unit. R
The data transmitted from the DF control unit 900 to the reader control unit 700 is a paper feed completion signal or the like indicating the completion of feeding the original onto the platen glass.

H. Sorter Control Unit (1000) FIG. 29 is a block diagram showing the circuit configuration of the sorter control unit 1000. This device is a central processing unit (CP
U) 1001, read-only memory (ROM) 100
2, a control device 1000 including a random access memory (RAM) 1003, an output port 1004, an input port 1005 and the like is provided, a ROM 1002 stores a control program, and a RAM 1003 stores input data and work data. There is. Also, the output port 100
4 is connected to various motors such as the shift motor 416 described above, the input port 1005 is connected to each sensor and switch from S401 to S406 such as the non-sorted path sensor S401, and the CPU 1001 is in the ROM1.
The respective units connected via the bus are controlled according to the control program stored in 002. Further, the CPU 1001 has a serial interface function, performs serial communication with the CPU of the printer control unit 701, and controls each unit by a signal from the printer control unit 701.

Next, the sorter controller 10 in this embodiment.
The control flow of 00 will be described with reference to the flowcharts of FIGS. 30 to 46 and FIGS. 47 and 48.

(1) Mode Processing First, referring to FIG. 30, the mode processing, which is the overall processing of this embodiment, will be described. In step 101, it is determined whether or not there is a "sort start signal" indicating that the sheet discharge from the copying machine main body is started.
Go to 103. If there is no "sort start signal" at step 101, the on / off of the manual staple key is checked at step 125, and if it is on, the curl of the sheets stacked in the bin is determined by the retract sequence (step 2050: described later) (Fig. 43). After being suppressed, the original bin is restored by the restoration sequence (step 2100: described later) (FIG. 44), and the manual stapling process (step
p800: described later) (FIG. 38) is performed, and curl of the sheets stacked in the bin is suppressed again by the retracting sequence (step 2050: described later). If the manual staple key is not turned on, step 900 (Fig. 39)
The stacking state monitoring process (described below) is performed, and thereafter, it is determined that there is no paper through all the bins (step 131), and if there is no paper, the process returns to step 101. If there is paper, the bin position is initialized (step 133), and then step
The process is returned to 101.

At steps 103 to 107, the mode relating to the storage of the sheets discharged from the copying machine is discriminated, and the process proceeds to each process described later. That is, in the non-sort mode, a non-sort process (step 1) described later is performed.
03, step 200), sort processing (step 105, step 300) described later in the case of sort mode, and group processing (step) described later in the case of group mode.
107, step 400), and in cases other than the above, the process proceeds to stack processing (step 500) described later. After each of the above processing, curl of the sheets stacked in the bin is suppressed by a retreat sequence (described later), and if the staple mode is then set (step 117), the sheet is returned to the original bin position by a return sequence (described later). Then, a stapling process (step 600) described later is performed, and after curl of the sheet in the bin is suppressed by a retracting sequence (described later), the process is returned to step 101.

(2) Non-sorting process Next, the operation of the above-mentioned non-sorting mode will be described with reference to FIG. First, in order to store the sheets in the uppermost bin, the bin unit is lowered to the non-sort home position for initialization of the bin (step 201). Then, the conveyance path 4 is used as a sheet conveyance path inside the sorter.
The flapper 409 is switched to select 06 (s
(Step 203). The flapper 409 has a drive solenoid (not shown) for switching it, and when it is normally off, it is at a position where the transport path 407 is selected, and when it is on, the transport path 406 is selected. . After step 203, in step 205, the conveyance motor for conveying the sheet is turned on, the pass sensor is turned on,
Check off (step 207), step1
The process proceeds to the stored number counting process of 050 (FIG. 40) (described later). In other words, this is to count the number of sheets that will be stored in the bin after passing through the transport path. After that, after performing the overload monitoring process (step 1100: described later) (FIG. 41), the presence or absence of the “sorter start signal” is checked (s
Perform step 209). If the "sorter start signal" is on, the process returns to step 207, and if it is off, the transport motor is stopped at step 211, and then step 2
At 13, the flapper is turned off and the non-sorting process ends.

(3) Sorting Process Next, the operation of the sort mode described above will be described with reference to FIG. First, it is determined whether the bin position to start the operation is designated (step 327), and if it is designated, the bin is moved to that position (step 329). If not specified, check whether there is a "bin initial signal" for storing sheets from the top bin (step).
301), if there is no "bin initial signal", ste
p305, and if there is, go to step 303. step
In 303, the bin unit is lowered to the non-sort home position as the bin initialization. step305
Then, the carry motor is turned on, and then the pass sensor is checked to be turned on (step 307). If the pass sensor is not turned on in step 307, the process proceeds to step 323, and if it is turned on, in step 309, the aligning rod is retracted to perform the aligning operation on the discharged sheet later. After that, when it is detected that the pass sensor is off, an alignment operation with respect to the stored sheets is performed (step 313), a number of sheets is counted (step 1050) (FIG. 40), and an overload monitoring process (step 1100) (FIG. 41) is performed. Then, in step 315, the matching rods are saved according to the presence or absence of the shift direction inversion signal (step 317), 1-bin shift (step 319) and inversion processing (step 32).
Perform 1). In the inversion process, the subsequent process for inverting the bin shift direction is performed, and the bin shift operation is not performed. Then, if the "sorter start signal" is turned on in step 323, the process is returned to step 307, and if the "sorter start signal" is turned off, the carry motor is stopped in step 325 to end the sorter process.

(4) Group Processing Next, the operation of the above-mentioned group mode will be described with reference to FIG. First, it is determined whether the bin position for starting the operation is designated (step 427), and if it is designated, the bin is moved to that position (step 429). If not specified, check whether there is a "bin initial signal" for storing sheets from the top bin (step
p401), if there is no "bin initial signal", st
ep405, and if there is, go to step403. ste
In p403, the bin unit is lowered to the non-sort home position for bin initialization. step40
In 5, the conveyance motor is turned on, and then the pass sensor is checked to be turned on (step 407). If the pass sensor is not turned on in step 407, the process proceeds to step 423, and if it is turned on, in step 409, the aligning rod is retracted to perform the aligning operation on the discharged sheet later. After that, when it is detected that the pass sensor is off, a sheet aligning operation is performed (step 413), a number of sheets is counted (step 1050) (FIG. 40), and an overload monitoring process (step 1100) (FIG. 41) is performed. Then, if there is a bin shift signal in step 415, if there is a bin shift signal, the matching rod is retracted (step 417) and shifted by 1 bin (step 419).
Go to 3. If the "sorter start signal" is turned on in step 423, the process is returned to step 407, and if the "sorter start signal" is turned off, st
At ep425, the carry motor is stopped and the sorting process is ended.

(5) Stack Processing Next, the operation of the above-mentioned stack mode will be described with reference to FIG. First, it is determined whether a bin position to start the operation is designated (step 527), and if it is designated, the bin is moved to that position (step 529). If there is no designation, first check whether there is a "bin initial signal" for storing sheets from the top bin (s
Step 501), if there is no "bin initial signal", go to step 505, and if there is, go to step 503. s
At step 503, the bin unit is lowered to the non-sort home position for bin initialization. step
In 505, the carry motor is turned on, and then the pass sensor is checked to be turned on (step 507). step507
If the pass sensor is not turned on at step 523, the process proceeds to step 523, and if it is turned on, at step 509, the aligning rod is retracted because the aligning operation is performed later on the discharged sheet. After that, when it is detected that the pass sensor is off (step 511), the alignment operation to the sheet is performed (st
ep513), number counting process (step 1050)
(FIG. 40), overload monitoring process (step 1100)
(FIG. 41) is performed. Then, in step 515, if the number of stored bins that have been stored does not reach the upper limit, step
p523, if it has reached, retreat the matching rod (step5
17) and 1-bin shift (step 519). Then, if the "sorter start signal" is turned on in step 523, the process is returned to step 507, and if the "sorter start signal" is turned off, the carry motor is stopped in step 525 to end the stack process.

(6) Stapling Process Next, the stapling process will be described with reference to FIG. FIG. 36 is a flowchart showing the stapling process flow. First, in step 601, the bin position is initialized for a series of stapling processes. The bin position initialized is the position of the uppermost or lowermost bin in use. When the movement is completed, the shift direction is set downward when the position is at the upper side, and the shift direction is set upward when the position is at the lower side.
Then, the process proceeds to step 700 to perform the stapling operation process. Details of the staple operation processing step 700 will be described later. When the stapling process is completed, the program
In step 609, it is determined whether or not the stapled bundle is the final bundle in a series of stapling processes. If it is the final bundle, the stapling process is ended, but if it is not the final bundle, it is shifted by 1 bin and then the process returns to step 700 to continue the process.

Details of the stapling operation process will be described with reference to the flowchart of FIG. First, in step 901, it is determined whether or not the stapler has staples for stapling. If there is a needle, the program proceeds to step 903, and the bundle is held by the aligning rod so that the bundle does not shift. Next, the process proceeds to step 905, stapling is performed, and st
At ep907, the aligning rod is retracted, and the stapling process at one place is completed. When it is determined that there is no needle in step 901, the process proceeds to step 913, the needleless alarm is output to the main body, and the process ends.

(7) Manual Stapling Process Next, the manual stapling operation will be described with reference to FIG. Manual staple is a stack of paper on the bin,
Alternatively, it is a mode in which the user staples a sheet bundle inserted in the bin, and staples only one bin.
First, at step 801, the stapler is moved to the staple position. When the movement is completed, the stapler paper sensor a near the stapler determines whether or not there is paper in the stapler portion (step 803). If there is paper, the program proceeds to step 805 and staples with stapler a. If it is determined in step 803 that there is no paper in the stapler a portion, or after stapling with the stapler a is completed in step 805, the program is
Proceed to step 811. Then, the stapler is moved to the retracted position, and the process ends.

(8) Loading State Monitoring Process Next, the loading state monitoring process will be described with reference to FIG. First, the counter on the program: i is cleared (step 901). Then, in step 903, the counter is incremented by 1, the sheet detection sensor in the i-th bin from the highest bin is checked (step 905), and if there is no paper, the process proceeds to step 909. Set load counter: Ni 0
To clear (step 907). After that, the same processing is performed for all the bins (step 903 to step 903).
909), after the end of the final bin (step 909), the processing is completed.

Next, the stored number counting process will be described with reference to FIG. In step 1001, the counter on the program: i is set to the bin number from which sheets are to be discharged, and in step 1003, the stacking sheet counter corresponding to the i is incremented by 1, and the process ends.

Next, the overload monitoring process will be described with reference to FIG. In step 1103, it is determined whether or not the number of sheets currently stored in the bin is larger than the preset maximum number of sheets to be stacked. If the number of stacked sheets is not more than the upper limit number, the process is terminated, and if the number of stacked sheets is more than the upper limit sheet, an overload alarm is output to the printer body (step 1105).
This overload alarm is communication data that informs the printer that more than the set number of sheets have been stored in the sorter. When the printer receives this data, the sheet for image formation is promptly sent. To stop the sheet feeding to the sorter (to continue the operation after releasing the alarm).

Next, the storage process will be described with reference to FIG. First, it is determined whether the output is a copy output (step 1201). If the determination is affirmative, step 120
3, the process proceeds to step 1221 if the determination is negative. s
At step 1203, the bin counter k is initialized to 0.
In step 1205, the counter k is incremented by 1, and it is determined whether or not a sheet is stored in the kth bin (st
ep1207). At this time, if stored, step1
Returning to 205, if not stored, store in the kth bin (step 1209). If the stored sheet is the final sheet, the process is terminated. If not, it is determined whether there is a storage bin change request (step 1213). If there is no request, the process returns to step 1209, and if there is a request, the bin counter k Is incremented by 1 (step121
5) Return to step 1209.

In step 1221, the bin counter k is initialized to N + 1. In step 1223, the counter k is decremented by 1 and it is determined whether or not the paper is stored in the kth bin (step 1225). At this time, if it is stored, the process returns to step 1223, and if it is not stored, it is stored in the kth bin (step 1227). Then, if the stored paper is the final paper, the processing is terminated, and if not, it is determined whether or not there is a storage bin change request (s
If there is no request, the process returns to step 1227. If there is a request, the bin counter k is decremented by 1 (step 1233), and the process returns to step 1227.

Next, the save sequence processing will be described with reference to FIG. In step 2051, a target evacuation position is calculated, and if the result (step 2053) is the same as the current bin, evacuation of evacuation is not necessary, so an evacuation alarm is set (step 2061) and the processing ends, and a different value is set. In case of current bin position (BIN_
POS) is stored in the return position (RET_BIN) (s
(Step 2055), the moving operation is performed to the retracted position (ESC_BIN) (step 2057). Then, after the moving operation is completed, the evacuation alarm is cleared and the evacuation state flag is set (step 2059).

Next, the return sequence processing will be described with reference to FIG. At step 2101, it is checked whether the evacuation state is set, and if it is not the evacuation state, it is not necessary to recover. Therefore, an evacuation alarm is set (step 2
109) to end the processing, and if it is in the retracted state, move to the return position (RET_BIN) (step).
2103, step 2105). Then, the evacuation alarm is cleared and the evacuation status flag is set (step 2
107).

Next, the movement operation will be described with reference to FIG. First, the current bin position (BIN_POS) and the movement destination (MOV_BIN) are compared (step 2201),
If they are the same, the process is terminated, and if they are different, step2
The processing is moved to 203. In step 2203, the magnitude relationship between the current bin position (BIN_POS) and the movement target position is determined, and if the movement target bin is smaller, it is shifted down by 1 bin (step 2205) and the current position counter is decremented by 1 (step 2207). To do. If the moving target bin is larger, the bin is shifted up by 1 bin (step 2209) and the current position counter is incremented by 1 (step 2211).

Next, the calculation of the retracted position will be described with reference to FIG. First, the bin position counter (BIN_C
N (20) (the number representing the position of the bottom bin in this configuration) is set in N) (step 2301).

Then, the bin position counter (BIN_C
Check the number of stacked sheets (VOL (BIN_CN)) loaded in the bin indicated by N), and the number is “0”.
If so, the process moves to step 2309, and the bin position counter (BIN_CN) at that time is moved to the save position (ESC_CN).
BIN). If the number of stacked sheets is other than "0", it is confirmed whether the bin position counter is "1" (step 2305). If it is not "1", the bin position counter (BIN_CN) is decremented by 1 and the processing is performed. st
Return processing to ep2303 is continued, and if “1”, st
The processing is moved to ep2309, and the calculation processing is ended.

Next, the evacuation sequence will be schematically described with reference to FIGS. 47 and 48. In this embodiment, the original 3
The following shows the sort mode with the number of sheets and the numeral number 3. FIG. 47 shows the bin state and the stacking state of the sheets at the time when the sort mode processing is finished, and the bin II-III is the bin between the bin in which the paper III- is finally ejected and the bin above it. Wider than between bins. Therefore, the above-mentioned paper III- does not receive the clamping force from the bins II and III. For this reason, the paper curls in the process of cooling the heated toner on the paper.

On the other hand, FIG. 48 shows the bin state and the sheet stacking state at the time when the retracting sequence is performed, in which the bins of each bin are constant and the sheets are sandwiched. As a result, since the paper is pressed while the toner on the paper cools, the occurrence of curling can be reduced.

The curl motor driver 763 is a curl motor driver, and drives the curl motor which is the drive source of the curl correction unit 500 (not shown) and the eccentric cam motor 507 shown in FIG.

Next, the curl correction unit 500 in this embodiment.
The detailed control method for the sorter 400 will be described.
First, an outline of curl correction control in the curl correction unit 500 will be described, and details will be described using a flowchart.

As shown in FIG. 22, the single-sided output paper is often discharged from the heat roller fixing device 9 in a normal curl state (convex downward). It is known that the positive curl of the sheet is caused by the toner heated and melted by the heat roller fixing device 9 and contracted by air cooling after discharging.
The curl amount changes depending on the image density (toner amount), the type of paper (material, rigidity, thickness, size, grain direction, etc.) and the surrounding temperature and humidity environment. We also know that there is a correlation.

In the present invention, in addition to the above factors, the sorter 40
By providing the optimum curl correction control by comprehensively judging the 0 operation mode, the presence / absence of stapling, and the partial image density (toner amount), the quality of the output paper in the final form can be improved. To achieve.

First, a method of calculating the partial image density (toner amount) in the first embodiment will be described. To simplify the description, the partial image density (toner amount) will be described as an example in which the partial image density is divided into two in the paper transport direction, and the intrusion amount x in FIG. 22 that determines the curl correction amount can be switched to three levels. To do.

The following will be described with reference to the flowchart of FIG. 23 and FIG. FIG. 23 is a flowchart of the curl correction control unit, and the control is started when the image formation of the final color is completed (S6000).

The image density (toner amount) is obtained by sampling the potential at the time of image formation by the potential sensor 12 and averaging it.
Then, the toner amount is converted from the relationship between the potential amount and the toner amount obtained from the experiment. The toner amount here indicates the same numerical value even if the paper size is changed, as long as the toner amount per unit area is a uniform density. Color image (4
When forming (color), the toner amount is expressed by the sum of the magenta toner amount, the cyan toner amount, the yellow toner amount, and the black toner amount.

This toner amount calculation operation is performed after the image formation of the final color black is completed, and the first half average toner amount TNRtop, the second half average toner amount TNRbottom,
Three toner amounts of the total average toner amount TNRtotal are calculated (S6001).

Next, the calculated toner amount is selectively used depending on the stacking mode for the sorter 400. In the non-sort mode (S6002), since there is no matching operation, the load amount is more important than the load quality. Therefore, the total average toner amount TN is used as the toner amount for determining the intrusion amount.
Rtotal is used (S6004).

Next, in the sort mode and the staple sort mode in which stapling is performed at the end of the job (S600
3) Since the portion to be stapled is the latter half of the sheet, the latter half average toner amount TNRbottom is used as the toner amount for determining the intrusion amount (S6005).

Next, when neither the non-sort mode nor the staple sort mode is set, that is, when the sort mode or the group mode is set, the first half average toner amount TNRtop and the second half average toner amount TN are used to improve stacking quality.
The one having the larger Rbottom is used as the toner amount for determining the intrusion amount (S6006). In this case, the curl correction quality particularly when the toner amount is deviated is significantly improved as compared with the case where the total average toner amount TNRtotal is used.

With this, the toner amount for determining the intrusion amount that determines the curl correction performance is determined. A method of determining the toner amount and the intrusion amount X will be described with reference to FIG. In the present embodiment, the intrusion amount x can be switched among three levels, which will be expressed as small intrusion amount, medium intrusion amount, and large intrusion amount. Since the curl amount is proportional to the toner amount as described above, when the total toner amount is taken on the horizontal axis, the switching point data 1 for small intrusion amount and medium intrusion amount and the switching point data for medium intrusion amount and large intrusion amount There are two. Further, since the curl amount depends on the paper size and the grain size, the data 1 and the data 2 are determined according to each paper size. Table 28 shows this. Further, since the curl amount also depends on the type of paper, the thickness, etc., data corresponding to the table of FIG. 24 is prepared depending on the type of paper on which images can be formed, the type of OHP paper, and the thick paper.

From this table 28, the penetration amount switching data for each paper size is determined, and the penetration amount is determined from the above-mentioned penetration amount determining toner amount (S6006).

FIG. 3 shows the image processing unit 20 in this embodiment.
3 is a block diagram illustrating a configuration example of FIG. 10 in FIG.
Reference numeral 1 denotes a CCD reading unit, which is an amplifier for amplifying each analog RGB signal input from the above-mentioned full-color sensor 34 (see FIG. 1), and an A / A for converting the analog RGB signal into, for example, an 8-bit digital signal. D
It is composed of a converter, a known shading correction circuit for performing shading correction, and the like, and outputs a digital RGB image signal of an original image.

Reference numeral 102 denotes a shift memory, which responds to a shift amount control signal from the reader controller 700,
The RGB image signals input from the D reading unit 101, for example, are corrected for deviations between colors and pixels. Reference numeral 103 denotes a complementary color conversion circuit, which is an RGB input from the shift memory 102.
The image signal is converted into an MCY image signal. A black extraction circuit 104 extracts a black region of the image from the MCY (magenta, cyan, yellow) image signal input from the complementary color conversion circuit 103 according to the black extraction signal input from the reader controller 700, and extracts the black region. B for the black area
Outputs a k (black) image signal.

Reference numeral 105 denotes a UCR circuit, which is a black extraction circuit 1
Undercolor removal (UCR) processing is performed on the MCY image signal input from the complementary color conversion circuit 103 according to the Bk image signal input from 04 and the UCR amount control signal input from the reader controller 700. That is, the black extraction circuit 10
4 and the UCR circuit 105 set the extracted black area to MCY3.
It is intended to improve color reproducibility by forming an image by replacing Bk toner instead of overlapping color toners.

The Bk image signal output from the black extraction circuit 104 is determined by the following equation (1).

BK = A · min (C2, Y2, M2) (1) In the equation (1), A is a black extraction coefficient, C2, Y
2 and M2 are MCY image signals output from the complementary color conversion circuit 103. The black extraction coefficient A is determined by the reader controller 7
00 to determine the black extraction amount control signal.

Further, the M output from the UCR circuit 105
The CY image signal is determined by the following equation (2). M1 = B1. (M2-D1.Bk) C1 = B2. (C2-D2.Bk) (2) Y1 = B3. (Y2-D3.Bk) M2, C2 and Y2 in the equation (2) MCY image signals output from the complementary color conversion circuit 103, M1, C1,
Y1 is the MCY image signal output from the UCR circuit 105, and the coefficients B1, B2, B3, D1, D2, D3 are determined by the reader controller 700 according to the UCR amount control signal.

Next, a masking circuit 106 is provided for the reader controller 700 to remove the turbid component of the toner used and to correct the RGB filter characteristics of the CCD.
In response to the masking coefficient control signal input from
Masking processing is performed on the MCY image signal input from the R circuit 105. M output from the masking circuit 106
The CY image signal is expressed by the following equation (3).

[0100]

[Outside 1]

In the equation (3), a11 to a33 are masking coefficients, and M1, C1 and Y1 are UCR circuits 105.
M0, C0, Y0 are MCY image signals output from the masking circuit 106, and the masking coefficients a11 to a33 are determined by a masking coefficient control signal designated by the reader controller 700.

Reference numeral 107 denotes a selector, which selects the M, C, Y, and Bk image signals input from the masking circuit 106 and the black extraction circuit 104 according to the color selection signal input from the reader controller 700 to the selection terminal S. The image signal of one color is selected from the inside and the image signal V1 is output.

Reference numeral 108 denotes a reader gradation correction circuit, which performs gradation correction as shown in FIG. 4 on the image signal V1 input from the selector 107 and outputs an image signal V2. For example, the reader gradation correction circuit 108 performs density correction on the image signal according to any of the conversion characteristics a to e of FIG. 4 selected based on the gradation correction selection signal designated by the reader controller 700. The setting in the reader gradation correction circuit 108 is determined by the image density setting of the operation unit described later.

Reference numeral 109 denotes a printer gradation correction circuit. An example is shown in FIG. 5 in accordance with a printer color selection signal input from the printer controller 701 in order to make the output characteristic of the printer unit 202 linear for each color. Any one of the gamma conversion characteristics m, c, y, bk is selected to correct the image signal.

Reference numeral 110 denotes a laser driver, which is included in the laser exposure optical system 3 (see FIG. 1) described above. The laser driver 110 forms a latent image on the photosensitive drum 1 by modulating and driving the semiconductor laser based on the image signal V3 input from the printer gradation correction circuit 109.

FIG. 6 shows the operating section of the color image forming apparatus of the present invention. In FIG. 6, reference numeral 351 is a ten-key pad, which is used for setting the number of image formations and inputting numerical values for mode setting. A clear / stop key 352 is used to stop the set number of image formations and the set image formation operation. Reference numeral 353 denotes a reset key for returning the set number of images to be formed, the operation mode, the selected paper feed stage, and the like to the specified values. Reference numeral 354 denotes a start key. Pressing the start key 354 starts the image forming operation.

Reference numeral 369 denotes a display panel made of liquid crystal or the like, and the display contents change depending on the setting mode in order to facilitate detailed mode setting. In this embodiment, the cursor keys 366 to 368 move the cursor on the display panel 369, and the OK key 364 determines the setting. Such a setting method can also be configured with a touch panel.

A paper type setting key 371 is set when an image is formed on a recording material thicker than the standard. When the thick paper mode is set by the paper type setting key 371, the LED 3
70 is controlled to light up. In this embodiment, only the thick paper mode can be set, but if necessary, the OHP
The functions can be extended to allow setting of modes for special paper and other types of paper.

A double-sided mode setting key 375 includes, for example, a "single-sided mode" for single-sided output from a single-sided original, a "single-sided mode" for double-sided output from a single-sided original, and a double-sided output for a double-sided original. Both-both mode ", 2 from two-sided original
It is possible to set four types of two-sided mode, that is, a "two-sided mode" for outputting one side of a sheet. The LEDs 372 to 374 are turned on according to the set double-sided mode, and "single-sided mode".
Then, all the LEDs 372 to 374 are turned off, and in the "single-both mode", only the LED 372 is turned on, "both-both mode"
Only LED 373 lights up in L, and L in "double-sided mode"
Only the ED 374 is controlled to light up.

(Specific Example of Image Formation) In the following, as a specific example, a "single-sided image processing" which does not use the automatic document feeder RDF600
The four-color image forming operation for plain paper for which the thick paper mode is not set in the "single mode" will be described.

In this case, since the recording material on which the image is formed is plain paper, the speed setting for the fixing drive motor driver 761 is set to the same VFN as the image forming speed (process speed) VP of the photosensitive drum 1. Set.

After the operator sets the number of images to be formed with the ten keys 351 and selects the paper feed stage with the paper selection key 303 and instructs the operation start with the start key 354, the printer controller 701 displays the drive motor required for image formation. For example, it instructs each driver of the photosensitive drum drive motor, the fixing drive motor, the paper feed drive motor, and the main drive motor to drive. Next, after the driving states of these drive motors are stabilized, the feeding operation of the recording material P is started from the designated paper feeding stage (recording material cassettes 7a, 7b, etc.). At this time, at substantially the same time, the reader unit 201 generates the image signal for magenta, which is the first developing color in the four-color mode, so that the above-described shift amount, black extraction amount, and UC
The R amount, the leader color selection signal, and the like are set in each block of the image processing unit 203. In addition, the reader gradation correction circuit 10
8 selects any of the conversion characteristics a to e shown in FIG. 4 corresponding to the contents designated by the density keys 304 and 306 of the operation unit 704. Further, the printer gradation correction circuit 109 is shown in FIG.
The conversion characteristic of m shown in is selected.

The recording material P fed from the designated paper feed stage is sent by the registration roller 50 at the same timing as the optical scanning operation of the reader section 201, and the attraction charger 5c and the attraction roller which is a counter electrode. 5 g is adsorbed on the transfer sheet 5 f.

Further, the document information read by the reader unit 201 is processed by the image processing unit 203, and the charger 2
The photosensitive drum 1 that has been uniformly charged by is irradiated with laser light to form a latent image, and is first developed by the magenta developing device 4m. The developed image information is transferred by the transfer charger 5b onto the previously adsorbed recording material P. In this image forming operation such as M (magenta) document reading, latent image formation, development, and transfer, the photosensitive drum 1 and the transfer drum 5a perform 1
This is executed during rotation, and similarly for the remaining three colors of C (cyan), Y (yellow), and Bk (black). Further, at this time, the setting for the image processing unit 203 is performed every time image formation is performed.

The recording material P on which the four color images have been transferred in this manner is separated from the transfer sheet 5f. At that time, the separation charger 5h weakens the attraction force between the transfer sheet 5f and the recording material P, the separation push-up roller 8b deforms the transfer sheet 5f to perform curvature separation, and the separation claw 8a performs the transfer sheet 5 transfer.
The recording material P is separated from f.

The recording material P separated in this way is conveyed to the heat roller fixing device 9 by the recording material conveying section 9g which conveys at the same speed (VP) as the transfer drum 5a, and the fixing speed VFN = VP. After being fixed by, the curl correction is performed by the paper output curl correction unit 500, and then the sorter 400
Is discharged.

Next, the control for the oil cleaning member will be described in detail. Since the control method of the oil cleaning control differs depending on the fixing speed, the oil cleaning control on plain paper will be described first.

First, the control when the oil cleaning member is not operating in the plain paper mode (control when oil cleaning is not performed) will be described, and then the control when the oil cleaning member is operating in the plain paper mode (oil cleaning). Control at the time of implementation) will be described.

(Control for not performing oil cleaning in plain paper mode) FIG. 7 shows the transfer operation of the final color from the start of the transfer operation of the final color to the final paper (the last of a plurality of sheets on which the image of the same original is formed). It is a flowchart showing the control until the image forming operation is stopped, and such control is usually “post-rotation control”.
It is said that. By this post-rotation control, "normal cleaning control" of the transfer drum 5a which is the recording material gripping means is executed.
The normal cleaning control is performed by the fur brush 14 as described later.
And the normal cleaning control using the fur buffer brush 15.

FIG. 8 is a flowchart of the flowchart of FIG.
When the transfer drum 5a is of a size capable of controlling two sheets of sticking, a timing chart when "single sheet of sticking control is performed by fixing (N) rotation control", which will be described later, and FIG. 9 is a flow chart of FIG. 6 is a timing chart when the one-sheet pasting control or the two-sheet pasting control is performed by "(N + 1) rotation control".

In the flowchart of the post-rotation control in FIG. 7, when the transfer of the final color of the image forming color determined by the color mode is started (step S1000), first, it is determined whether it is the final sheet for the same original, that is, the final sheet. It is determined whether or not (step S1001). Thus, it is determined whether or not the post-rotation control is performed after the transfer is completed. If the image is not formed on the final sheet (hereinafter referred to as "final image formation"), the image forming operation is continued (step S100).
2) This control ends (step S1003).

In the case of the final image formation, the size of the recording material in the conveying direction is compared with the distance LTCLN from the transfer position to the transfer sheet cleaning position (step S100).
4). This is because when the recording material is applied to both the transfer position and the transfer sheet cleaning position (in this embodiment, the distance LTCN from the transfer position to the transfer sheet cleaning position is 250 mm), the transfer drum 5a moves during the transfer to the recording material. This is to prevent the image from being disturbed when the cleaning operation or the recording material separation operation is performed. When the recording material is applied to both the transfer position and the transfer sheet cleaning position, the transfer drum should be ended to end the transfer operation. After idling the 5a by one rotation (step S1005), the separating operation (step S1006) and the cleaning operation (step S1008) are performed.

In the normal cleaning control in step S1007, the fur brush 14 is rotated by a motor (not shown), the fur backup brush 15 facing the fur brush 14 is enabled, and the fur brush 14 is applied to the transfer sheet 5f. Just touch them. At this time, the transfer sheet 5f for one round of the transfer drum 5a is cleaned regardless of whether the one-sheet attachment control or the two-sheet attachment control is performed.
The cleaning operation of is finished (step S1009). After that, the load and the high voltage of the operating motor are stopped (step S1009), and the image forming operation is ended (step S1).
010).

(Control during execution of oil cleaning in plain paper mode) When forming a single-color image on both surfaces of plain paper, at the time of image formation on the second surface of both surfaces (hereinafter referred to as "plain paper single color on both surfaces").
(Also referred to as), the oil cleaning operation of the transfer sheet 5f is executed as follows.

The recording material, which is fed from any of the cassettes and on which the image is formed on the first side, is once stored in the intermediate tray 22 and then re-fed. The number of re-fed recording materials is 2
It is carried on the transfer drum 5a for image formation on the first side.
At this time, the surface of the transfer sheet 5f of the recording material is 1
The oil which is in contact with the image forming surface of the first surface and adheres in the fixing device 9 at the time of forming the image of the first surface is the transfer sheet 5f.
Will be reattached to the surface of. It is necessary to avoid this oil from adhering to the photosensitive drum 1. To this end, when the transfer sheet 5f during image formation on both sides of the second surface passes the transfer position, the transfer sheet 5f that passes the transfer position. Must be cleaned in advance with oil or controlled so that the recording material is present between the transfer sheet 5f and the photosensitive drum 1. When the fixing speed is the same as the process speed on both sides of plain paper single color both sides, the recording material is always placed between the transfer sheet 5f and the photosensitive drum 1 at the transfer position when images are continuously formed on a plurality of recording materials. Since it exists, it suffices to perform oil cleaning only during the above-described post-rotation control.

By the way, it is considered that the recording material for image formation on the second surface of both sides is fed from the intermediate tray 22 and is fed from the recording material tray 7m. The recording material tray 7m may be reset by the user in order to output a double-sided image on the recording material that has been subjected to image formation. In this case, in the same manner as the paper feeding from the intermediate tray 22, the first surface is printed. Control is performed assuming that there is a recording material for the second side of both sides on which an image is formed.

Next, the oil cleaning control will be concretely described with reference to the flowchart of FIG. This FIG. 10 shows both sides 2
An example will be shown in which the oil cleaning and the normal cleaning are performed on the surface, and only the normal cleaning is performed at other times.

Cleaning of the transfer drum is started (step S150
0) If the paper feed position is the intermediate tray 22 or the recording material tray 7m, it is determined in step S1501 that image formation is for the second side of both surfaces, and the oil cleaning backup brush 17 is used to perform the oil cleaning operation. It is validated (step S1502), the oil cleaning roller 16 is driven and brought into contact with the transfer sheet 5f (step S15).
03). Since the oil cleaning roller 16 is made of a material that absorbs oil, the oil cleaning roller 16 comes into contact with the transfer sheet 5f to remove the oil adhering to the transfer sheet 5f. Next, in order to perform normal cleaning, the fur backup brush 15 is enabled (step S1504), the fur brush 14 is driven to abut against the transfer sheet 5f (step S1505), and the cleaning operation is completed (step S1505). Step S1506). In step S1501, the paper feeding position is the intermediate tray 22 or the recording material tray 7.
If it is not m, oil cleaning is not necessary and only the fur brush 14 is driven for normal cleaning control (steps S1504 and S1505).

By the way, Steps S1500 to S1500 in FIG.
S1506 is the transfer drum cleaning control in FIG. 7 (step S
When it is executed in 1007), oil cleaning can be performed as necessary in the post-rotation control.
When steps S 1500 to 1506 in FIG. 10 are executed between steps S 1001 and S 1002 in FIG. 7, oil cleaning or normal cleaning is performed whenever necessary when the recording material is separated from the transfer drum 5 a. Can be carried out. Further, when steps S1500 to S1503 in FIG. 10 are executed between steps S1001 and S1002 in FIG. 7, only oil cleaning is performed as necessary each time the recording material is separated from the transfer drum 5a. It can be carried out.

(Peculiarity of fixing speed in thick paper mode)
Since more energy is required to fix toner on thick paper compared to plain paper, the fixing speed is slower than plain paper and the energy per unit area / hour is increased to increase the thickness of thick paper. It secures the fixability of.
In that case, conventionally, the separation claw 8a to the vertical fixing roller 9
By making the distance to the abutting positions of a and 9b larger than the maximum image-forming size of thick paper, the recording material conveying section can be maintained while keeping the peripheral speed of the transfer drum 5a, which is the image forming speed (process speed) VP, constant. At 9g, the recording material is decelerated to a fixing speed VF different from the speed of the transfer drum 5a, and the recording material conveying portion 9g is used as a speed conversion area. For this purpose, it is necessary to secure the recording material conveying section 9g having a size corresponding to the maximum size of thick paper on which an image can be formed, and there is a drawback that the apparatus becomes large.

Therefore, in this embodiment, the speed of the transfer drum 5a can be varied similarly to the fixing speed.
When the fixing speed VF has to be slower than the image forming speed VP, the speed of the transfer drum 5a is reduced to the fixing speed after the transfer of the final color is completed.
This eliminates the need to secure a size as a speed conversion area in the recording material conveying unit 9g, and avoids an increase in size of the apparatus.

By the way, when the size of the recording material in the conveyance direction is larger than the distance LTC from the transfer position in FIG. 1 to the tip position of the recording material conveyance section 9g, the deceleration to the fixing speed of the transfer drum 5a is the next recording. It is not in time for the material separation operation. In such a case, the transfer drum 5a is rotated one extra rotation, and the recording material separation operation is performed at the timing of the subsequent separation operation. In this manner, after the transfer of the final color in the thick paper mode is completed, the transfer drum 5a is rotated once more, the separating operation is performed, and the fixing operation is further performed. This control is hereinafter referred to as "fixed thick paper (N + 1) rotation control". Further, when the distance LTC from the transfer position to the leading end position of the recording material conveying unit 9g or the recording material conveying unit 9g can be used as a speed conversion area, that is, the transfer drum 5a is set to 1 extra.
The control when there is no need to rotate is referred to as "fixed thick paper (N) rotation control" below.

Here, in order to make the explanation easy to understand,
Assuming that the distance LTC from the transfer position in FIG. 1 to the leading end position of the recording material conveying unit 9g is 250 mm, the control is performed as follows in the thick paper mode with a typical recording material size.

A4 horizontal feed size (feeding direction 210 mm) 1 sheet stuck: fixing thick paper (N) rotation control A4 vertical feeding size (feeding direction 297 mm) 1 sheet sticking: fixing thick paper (N + 1) rotation control A3 vertical feeding size (feeding direction) 420mm) 1 sheet sticking: fixing thick paper (N + 1) rotation control A4 horizontal feed size (feeding direction 210mm) 2 sheets sticking: fixing thick paper (N + 1) rotation control

(Peculiarities of Oil Cleaning in Thick Paper Mode) Next, the oil cleaning control in the thick paper mode in which the fixing speed needs to be slowed will be described.

As described above, in the case of the oil cleaning control of the plain paper, since the speed of the transfer drum 5a is not changed after the image formation of the transfer drum 5a is completed, the image forming operation can be continuously executed and the oil cleaning can be performed. The control need only be performed at the end of the image forming operation for the final sheet of the document.

On the other hand, in the thick paper mode, the speeds of the transfer drum 5a and the photosensitive drum 1 are set to be the same as the fixing speed VFT for fixing control. The photosensitive drum 1 must be returned to the original speed VP again, and if the recording material is different, continuous image forming operation cannot be performed. Therefore, when an image is formed on the second side of thick paper, the oil adhered on the transfer sheet 5f adheres to the photosensitive drum 1 at the transfer position, and the transfer operation of the final color to each recording material ends. Oil cleaning control is required for each. Therefore, at the time of forming an image in the thick paper mode, the oil cleaning control is performed every time when the transfer operation of the final color onto each recording material is completed, as described below.

(Image Formation Control in Thick Paper Mode) The color image formation control in the thick paper mode will be described below with reference to the flowchart of FIG. The flowchart of FIG. 11 corresponds to all recording materials in the thick paper mode, the plain paper mode, and the OHP mode. So Figure 1
In 1, the control corresponding to the fixing thick paper (N + 1) rotation control and the fixing thick paper (N) rotation control is expressed as the fixing (N + 1) rotation control and the fixing (N) rotation control as common to all recording materials. ing.

As described above, sheet feeding, latent image including suction,
The development and transfer operations (step S2000) are repeated until the final color is transferred (step S2001). After the transfer of the final color, the fixing speed VF is compared with the image forming speed VP (step S2002). Here, in the thick paper mode, the fixing speed VF is a slow fixing speed VFT for thick paper, and since the fixing speed VF is different from the image forming speed VP, the process proceeds from step S2002 to step S2003.

In step S2003, the transfer sheet 5f
It is determined whether or not the mode is for holding a plurality of recording materials. In this embodiment, since electrostatic attraction is used as the recording material carrying means, in the case of a recording material of 1/2 or less of the entire circumference of the transfer sheet 5f, image formation can be performed on two recording materials at the same time. It is possible. In this example, when images are formed on two recording materials at the same time (two sheets are attached), the two recording materials are
Since it is handled as one sheet of recording material that includes the paper distances,
The distance LTC from the transfer position to the leading end position of the recording material conveying section 9g becomes smaller than the size of the recording material conveying direction treated as one sheet of recording material, and the recording material conveying section 9g from the transfer position.
It is assumed that the distance LTC to the tip position of g cannot be used as the speed conversion area. So, in this case,
Perform "fixing (N + 1) rotation control" (step S200)
6).

Next, when only one recording material is carried on the transfer sheet 5f and an image forming operation is carried out (one sheet is stuck), the distance LTC from the transfer position to the leading end position of the recording material conveying portion 9g is LTC.
And the size PX of the recording material in the recording material conveyance direction are compared (step S2004). When the size PX is larger than the distance LTC, the distance from the transfer position to the leading end position of the recording material conveying unit 9g cannot be used as a conversion area of the fixing speed, so that “fixing (N + 1) rotation control” is performed. (Step S2006). On the contrary, when the size PX is smaller than the distance LTC (step S2004),
Perform "fixing (N) rotation control" (step S200)
5).

In this example, the distance LTC and the size of the recording material in the conveying direction are compared. However, when it takes time to change the speed due to the performance of the drum motor, the time required for the speed change should be taken into consideration. Judgment step (step S20
03, step S2004) can be improved. In the fixing (N) rotation control, when the transfer sheet 5f is cleaned at substantially the same time as the recording material separating operation,
Since the cleaning operation of the transfer sheet 5f may adversely affect the recording material being transferred, it is necessary to change the control depending on the size in the recording material conveyance direction and the distance from the transfer position to the transfer sheet cleaning position. In this embodiment, the distance LTC
And the distance LTC from the transfer position to the transfer sheet cleaning position
The LNs are set to 250 mm and are equal to each other.

(Fixing (N) Rotation Control in Thick Paper Mode) The fixing (N) rotation control in the thick paper mode will be described below with reference to the timing chart of FIG. In FIG. 12, C corresponds to the image of cyan, Y corresponds to the image of yellow, and K corresponds to the image of black, and the reference signal of the transfer drum is the transfer drum 5a.
The photosensitive drum speed changes similarly to the transfer drum speed.

Fixing (N) rotation control (step S200
In 5), the operation is started after the start of the final color transfer (step S2001). The separating operation is the same as in the plain paper mode that is not the thick paper mode. That is, until the separation operation start timing t1 is reached, when the separation start timing t1 is reached, the separation claw 8a and the separation push-up roller 8b are operated to start the separation operation.

Next, the process waits until the transfer end timing t2, which is determined from the size PX of the recording material in the conveying direction. When the transfer end timing t2 is reached, the output of the transfer charger is set to OFF, and the photosensitive drum motor driver 760 is set.
On the other hand, the peripheral speed of the transfer drum 5a is set to be the same as the fixing speed VFT for thick paper. After that, it waits until the separation operation end timing t3, and the separation claw 8a is turned off to end the separation operation.

By the way, when such transfer is performed on the second surface of both sides in the thick paper mode, as described above, the fixing oil on the first surface of the recording material adheres to the surface of the transfer sheet 5f after separation. Therefore, step S200 in FIG.
8, it is determined that oil cleaning is necessary, and oil cleaning control is performed before the area of the transfer sheet 5f to which the fixing oil adheres reaches the transfer position again (step S200).
9). The oil cleaning is performed in step S of FIG. 10 described above.
Similar to 1502 and S1503, the oil cleaning backup brush 17 is enabled and the oil cleaning roller 16 is driven to contact the transfer sheet 5f. After all,
When the second side is the second side in the thick paper mode, the oil cleaning control is performed every time the recording material is separated.

Before the leading edge of the recording material reaches the recording material conveying portion 9g driven at the fixing speed VFT for thick paper, the peripheral speed of the transfer drum 5a becomes the same as the fixing speed VFT, and the recording material becomes Are normally separated and conveyed, and are fixed at the fixing speed VFT for thick paper. Then, after waiting until the discharge of the recording material is completed (step S2010), the speed of the transfer drum 5a, which is determined by the speed of the drum motor, is set to the speed VP for image formation in order to form an image on the next recording material. Set (Step S201
1).

After performing such a set number of operations (step S2012), the image forming operation is terminated.

(Fixing (N + 1) Rotation Control in Thick Paper Mode) The fixing (N + 1) rotation control in the thick paper mode will be described below with reference to the timing chart of FIG. FIG.
3 is an example when two sheets are pasted. In the figure, K1 is 1
Corresponding to the black image on the second recording material, Y2 and K2 correspond to the yellow and black images on the second recording material.

In this fixing (N + 1) rotation control, as described above, the size of the recording material in the conveying direction is larger than the distance LTC (= 250 mm) from the transfer position to the leading end of the recording material conveying section, and the distance between them is the fixing speed. When it cannot be used as a speed conversion area, after the transfer operation is completed, the transfer drum 5a is rotated once and then the separation operation is performed.

Therefore, the process waits until the transfer end time t11 of the final color of the second sheet of the recording material stuck to two sheets is reached, and when the transfer end timing t11 is reached, the high voltage of the transfer charger is turned off to perform the transfer operation. To finish. Next, the transfer drum 5
The peripheral speed of a is set to be the same as the fixing speed VFT for thick paper, and the fixing speed VFT is kept as it is until the separation start timing t12 in the next rotation. The separation operation is performed at the separation start timing t12,
After the separation operation is completed, the separation claw 8a is turned off and the operation is completed.

By the way, when such transfer is performed on the second surface of both surfaces in the thick paper mode, as described above, the fixing oil on the first surface of the recording material adheres to the surface of the transfer sheet 5f after separation. Therefore, step S200 in FIG.
8, it is determined that the oil cleaning is necessary, and the oil cleaning control is performed before the area of the transfer sheet 5f to which the fixing oil adheres reaches the transfer position again (step S20).
09). After all, when the fixing (N + 1) rotation control in the thick paper mode is the second surface of both sides, the oil cleaning control is performed every time the recording material is separated.

In this way, the transfer drum 5a makes one extra rotation to form a speed conversion region, and the fixing operation in the thick paper mode for the recording material up to the maximum image forming size in the normal operation is performed. Is possible. Also, 2
It is possible to realize the thick paper mode even in the operation of sticking sheets.

After waiting until the recording material is discharged (step S2010), the speed of the transfer drum 5a is set to the image forming speed VP for forming an image on the next recording material (step S2011).

After performing such an operation for the set number of sheets (step S2012), the image forming operation is ended.

(Fixing Normal Rotation Control in Plain Paper Mode) In the plain paper mode as compared with the thick paper mode described above, the image forming speed VP and the fixing speed are equal, and therefore, FIG.
1 from step S2002 to step S2007, and "fixing normal rotation control" is performed (step S200
7). In this fixing normal rotation control, the fixing speed is equal to the image forming speed VP, so images are continuously formed on the transfer sheet 5f, and the oil cleaning control is performed for the set number of sheets even in the image formation of the second surface of both sides. Is executed after the image formation is completed (steps S2013 to S2015).

FIG. 14 shows such control in comparison with FIGS. 12 and 13 in the case of the thick paper mode described above.
16 is a timing chart of FIG. 15. 14 is the same as the case of the thick paper mode shown in FIG.
FIG. 14 is a timing chart when two sheets are stuck, similar to the case of the thick paper mode of FIG. 13 described above.

For plain paper, when it is determined that oil cleaning is necessary in step S2014 after forming a set number of images, oil cleaning control (step S2015).
And then control ends. It is judged that the oil cleaning is necessary when the second side of the sheet is fed from the intermediate tray 22 or the recording material tray 7m as described above.

By the way, in the recording mode (OHP mode) for an OHP sheet having a fixing speed different from that of the thick paper mode, if the fixing speed is set to VFO, it can be applied to the OHP paper as in the case of the thick paper. .
When the second surface of the both surfaces is not in the single color mode, the fixing speed VFD is different from the process speed VP, and therefore the same oil cleaning control as that of the second surface of the thick paper mode may be performed.

Further, in consideration of the influence of the toner or the like attached to the first surface of the recording material on the fixing of the second surface, the fixing speed may be controlled to be slower on the second surface of both sides than on the first surface of both sides. This kind of control can be done in plain paper mode,
It can be executed regardless of the thick paper mode or the OHP mode.

(Recovery Control) Next, recovery control after paper jam detection (hereinafter, abbreviated as “jam detection”) in the image forming apparatus thus realized will be described with reference to the flowchart of FIG. As is well known, when a jam has occurred (step S3000), the conveyance of the recording material is stopped, and the occurrence of the jam is displayed on the operation unit (step S3000).
3001).

Thereafter, if the door that is opened to remove the jammed recording material is opened or closed (step S300)
2, S3003), it is confirmed by a sheet conveyance sensor (not shown) whether or not the recording material is removed from the sheet conveyance path or the transfer drum (step S3004). When the removed recording material includes the second-sided sheet of paper, the fixing oil on the image formed on the first side of the recording material adheres to the surface of the transfer sheet 5f when stopped. Therefore, in this case, steps S3005 to S3006
Then, the process proceeds to step 5 to perform the oil cleaning control and the transfer sheet 5f cleaning operation. On the other hand, when the second-sided sheet is not included, the oil cleaning control is not performed, and the transfer sheet 5 is formed only by the fur brush 14 and the fur backup brush 15.
After cleaning f (step S3007), the recovery operation is controlled (step S3008,
Steps S3009 and S3010).

The determination in step S3005 may be a determination as to whether or not oil cleaning control is necessary. If a paper jam that requires an oil cleaning control is detected, the oil cleaning control is performed before the recovery control. It is possible to prevent the fixing oil from adhering to the photosensitive drum 1 during the recovery control. In the present embodiment, since the presence or absence of oil cleaning control is determined according to the fixing speed and the paper feeding place, by expanding these judgment conditions, it is possible to perform oil cleaning control before recovery control in all cases. Become.

(Control of Polishing Roller 18) Next, the control of the polishing roller 18 will be described with reference to the flowchart of FIG.

The polishing roller 18 operates together with the polishing roller backup brush 19 which faces the polishing roller 18. Polishing roller 18
Is used to scrape off toner and adhering substances from the paper that cannot be removed even by cleaning with the fur brush 14. Therefore, a member having the same effect as sandpaper is wound around the outer periphery of the polishing roller 18, and by this member, it becomes possible to scrape off the adhered matter that cannot be cleaned by the fur brush 14. The operation of the polishing roller 18 is the transfer sheet 5a.
Therefore, for example, the polishing control is performed every 2000 image forming operations.

The polishing control in this embodiment is realized by driving the polishing roller 18 and the polishing roller backup brush 19 and rotating the transfer drum 5a by 20 rotations. Therefore, it takes about several minutes to execute the image forming operation during that time. Therefore, in order not to increase the image forming operation inhibition time for restraining the user, the polishing control is performed when the fixing roller is cold immediately after the power is turned on (step S4000). As a result, the polishing control is performed while the temperature of the fixing roller reaches the temperature required for image formation, and the image formation operation inhibition time is shortened.

Specifically, when both of the temperatures detected by the fixing upper thermistor 781 and the lower fixing thermistor 782 of the respective fixing rollers (9a, 9b) are 100 degrees or less, the above-described polishing control is performed (step S4001,
S4002). The determination as to whether or not to execute the polishing control when the power is turned on is not limited to this.
Whether or not the polishing control is performed may be determined based on the detection temperature of the fixing roller and the number of sheets after the polishing is performed.

When the fixing roller is heated so that the image forming operation can be performed, the desired mode is set by the operation unit, and the start key 354 is pressed (step S40).
03), the above-mentioned image forming operation is started (step S4).
004). At the end of the image forming operation for each sheet, the polishing control counter is decremented (step S
4005). This operation is repeated for the set number of sheets (step S4006). When the automatic document feeder RDF is used, the image forming operation for the set number of sheets for the final original document is repeated (steps S4007, S400).
8). At this point in time, all the image forming operations have been completed, so the polishing control counter decremented according to the image forming operation is checked (step S400).
6). When this counter is 0, it means that a predetermined number of images have been formed since the last polishing operation, and the polishing operation is necessary. Therefore, when the counter is 0, the polishing control for performing the polishing operation is performed (steps S4009 and S401).
0). Since an image forming operation cannot be performed during polishing control, a message to that effect is displayed on the operation unit. By doing so, polishing control can be provided to the user as a series of image forming operations.

Next, the content of the polishing control in step S4010 will be described with reference to the flowchart of FIG. If the polishing control is broken (step S410)
0), the fur brush 14 alone cleans the transfer drum 5a for one rotation to clean the toner on the transfer sheet 5f (step S4101). After that, the polishing roller 18 and the polishing backup brush 19 are driven (step S410).
2) The polishing operation is performed every time the transfer sheet 5f rotates by a predetermined rotation (20 rotations in this example) (step S41).
03). After the completion of the polishing operation for each predetermined number of rotations, the driving of the polishing brush 18 and the polishing backup brush 19 is stopped (step S4104), and the transfer drum 5 is restarted.
Cleaning is performed only by the fur brush 14 for one rotation of a (step S4105), and cleaning is performed to remove shavings or dust generated by the polishing operation. After that, the initial value (2000 in this example) is set to the polishing control counter for managing the number of sheets (step S4106), and the polishing control is ended (step S4107).

By the way, in this example, the number of recording materials is controlled from the time of the polishing control from the previous time, but in the case of the fur brush cleaning and the oil cleaning described above, the counter for such number management is independently set. With the provision, it is possible to prevent adverse effects on the apparatus due to a user's setting error when setting the type of paper and an operation error such as oil adhesion due to addition of output paper to the cassette.

(Cleaning Operation for Transfer Drum) Next, the execution of the cleaning operation for the transfer drum from the operation section will be described. In this embodiment, an environment that can be executed only by a service person, not by the user is provided, but it may be executed by the user as necessary.

By operating the operation unit 704 in a predetermined manner, the input screen of the service mode used only by the service person is displayed on the display panel 369. FIG. 19 shows a state in which the service mode related to the cleaning operation for the transfer drum is displayed. In this state, press the cursor keys (365, 3
66, 367, 368) and the OK key 364 to select and execute the cleaning mode. Since the oil removal mode is selected in FIG. 19, when the OK key 364 is pressed in this state, the oil removal mode is executed.

Hereinafter, the cleaning-related service mode for the transfer drum will be described with reference to the flowchart of FIG. First is the service mode, which is shown in FIG.
It is checked whether or not the transfer drum cleaning related service mode shown in 9 is set (step S5000). When it is affirmed, the input of the OK key 364 is monitored (step S5001), and the cleaning mode is confirmed at the time of the input. Then, the type of the selected cleaning mode is determined (steps S5002 and S5003), and if cleaning is selected, the process proceeds from step S50.
Proceeding to 06, transfer cleaning without oil removal is executed. This is step S30 in FIG. 16 described above.
The control is the same as 07, and the transfer sheet 5f is cleaned only by the fur brush 14 and the fur backup brush 15. On the other hand, when oil removal is selected, the process proceeds from step S5003 to step S5005, and transfer cleaning with oil removal is executed. This is the same control as step S3006 in FIG.
In addition to the fur brush 14 and the fur backup brush 15, the oil cleaning backup brush 17 and the oil cleaning roller 16 are driven to clean the transfer sheet 5f.

If a cleaning mode other than the above two is selected, the polishing control is executed (step S500).
4). This is to execute the oil removal control itself shown in FIG.

As described above, by selectively executing the cleaning operation for the transfer drum in the service mode, it is possible to shorten the service work, improve the efficiency, and form a high-quality image.

[0176]

As described above, according to the present invention, before the binding processing for the sheets on the tray is performed, the interval between the trays in which the sheets are not accommodated is widened and the interval between the trays in which the sheets are accommodated is increased. Since the sheet on the tray is pressed down by pressing the sheet, and the space between the trays in which the sheets are stored is controlled so as to be widened, curl growth of the sheet can be suppressed and the sheet binding process can be favorably performed.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a color image forming apparatus as an embodiment of the present invention.

FIG. 2 is a block diagram of a control system of the color image forming apparatus of FIG.

FIG. 3 is a block diagram of a control system of the image forming processing unit shown in FIG.

4 is a gradation correction characteristic diagram showing an example of input / output signals in the reader gradation correction circuit of FIG.

5 is a gradation correction characteristic diagram showing an example of input / output signals in the printer gradation correction circuit of FIG.

FIG. 6 is a schematic plan view of the operation unit shown in FIG.

7 is a flow chart for explaining the operation from the start of the final color transfer operation of the final paper to the stop of the image forming operation in the color image forming apparatus shown in FIG.

FIG. 8 is a timing chart when one-sheet sticking control is performed by fixing (N) rotation control in the flowchart of FIG.

FIG. 9 is the fixing (N + 1) in the flowchart of FIG.
It is a control timing chart at the time of performing one-sheet sticking control or two-sheet sticking control by rotation control.

FIG. 10 is a flowchart for explaining a transfer drum cleaning operation applicable in the flowchart of FIG.

11 is a flow chart for explaining fixing control in the color image forming apparatus of FIG.

FIG. 12 is a timing chart for explaining the fixing (N) rotation operation in the thick paper mode in the flowchart of FIG.

13 is a timing chart for explaining the fixing (N + 1) rotation operation in the thick paper mode in the flowchart of FIG.

14 is a timing chart for explaining a fixing (N) rotation operation in a plain paper mode in the flowchart of FIG.

FIG. 15 is a timing chart for explaining the fixing (N + 1) rotation operation in the plain paper mode in the flowchart of FIG.

16 is a flowchart for explaining a jam process in the color image forming apparatus of FIG.

17 is a flowchart showing a polishing control process in the color image forming apparatus of FIG.

FIG. 18 is a flowchart for explaining polishing control in the color image forming apparatus of FIG.

19 is a schematic plan view for explaining a display example of the display panel in the service mode in the color image forming apparatus of FIG.

20 is a flow chart for explaining a process of a transfer drum cleaning mode in the color image forming apparatus of FIG.

21 is a plan view of an OHP sheet usable in the color image forming apparatus of FIG.

FIG. 22 is a diagram showing a curl correction unit.

FIG. 23 is a flowchart of curl correction.

FIG. 24 is a diagram illustrating control of curl correction.

FIG. 25 is a sectional view showing a configuration of an automatic document feeder.

FIG. 26 is a configuration diagram of a sorter unit.

FIG. 27 is a configuration diagram of a sorter unit.

FIG. 28 is a block diagram showing an RDF control unit.

FIG. 29 is a block diagram showing a sorter control unit.

FIG. 30 is a control flowchart.

FIG. 31 is a control flowchart.

FIG. 32 is a control flowchart.

FIG. 33 is a control flowchart.

FIG. 34 is a control flowchart.

FIG. 35 is a control flowchart.

FIG. 36 is a control flowchart.

FIG. 37 is a control flowchart.

FIG. 38 is a control flowchart.

FIG. 39 is a control flowchart.

FIG. 40 is a control flowchart.

FIG. 41 is a control flowchart.

FIG. 42 is a control flowchart.

FIG. 43 is a control flowchart.

FIG. 44 is a control flowchart.

FIG. 45 is a control flowchart.

FIG. 46 is a control flowchart.

FIG. 47 is a diagram illustrating control.

FIG. 48 is a diagram illustrating control.

[Explanation of symbols]

 202 Printer 400 Sorter B Bin

Claims (3)

[Claims] 1. A transport unit configured to transport a sheet discharged from an image forming apparatus, a plurality of trays configured to store the sheet transported by the transport unit, and a plurality of trays configured to store the sheet in each of the plurality of trays.
Tray moving means for moving the positions of the plurality of trays with respect to the conveying means and for increasing the distance between the tray in which the trays are stored and the adjacent tray; and binding processing means for binding the sheets on the trays. Before performing binding processing by the binding processing means, widen the intervals of the trays that do not contain sheets, narrow the intervals of the trays that contain sheets, press the sheets on the trays, and then store the sheets. 2. A sheet storage device, comprising: a control unit that controls the tray moving unit so as to widen the interval between the existing trays. 2. The control means moves the tray so that after the binding processing means performs the binding processing, the spacing between the trays in which the sheets are not stored is widened and the spacing between the trays in which the sheets are stored is narrowed. The sheet storage device according to claim 1, wherein the means controls the means. 3. The sheet storage device according to claim 1, wherein the image forming apparatus forms an image by an electrophotographic process.