JPH10153930A - Image forming device provided with image erasing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To save the handling time of a user to the utmost when a toner image formed on a sheet is erased and the sheet is used again. SOLUTION: The sheet is placed on a paper supply tray for erasing an image 21 by facing the surface thereof on which the image is formed downward. The placed sheets are successively fed out to a carrying path 69 from the upper part thereof by a paper supply roller 21a. Then, the part other than the image is simultaneously read and the size of the sheet is detected by a contact type sensor 70. The unnecessary part other than the toner image formed on the sheet is eliminated by first and second cut devices 71 and 72 and reproduced as the sheet of such size that the image can be formed. The sheet reproduced to the sheet of the necessary size is fed by an image erasing device 60 and the image forming surface thereof is coated with processing solution by a nozzle 61. Thereafter, the image is eliminated by an elimination roller 62 heated to prescribed temperature. The sheet from which the image is erased is fed and housed in a paper supply tray 17 or a paper supply tray 18 communicating with the path 69 and housing the sheets of the respective size.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus, in particular, an apparatus for forming a desired image on a sheet, by erasing an image formed on the sheet, for example, a toner image, and reusing the sheet. And an image forming apparatus provided with the image erasing device.

[0002]

2. Description of the Related Art In an image forming apparatus using an electrophotographic system, a toner image is formed on a photoreceptor as a recording medium, and the toner image is transferred onto a sheet such as plain paper. In order to hold the toner as a permanent image on the sheet, the toner is fixed by, for example, passing through a heat fixing device, and then discharged to the apparatus main body.

According to this image forming apparatus, a desired image can be formed on a sheet. However, if the image on the sheet becomes unnecessary, if the image information formed on the sheet is a document or the like that is confidential, etc., the sheet may be cut finely with a shredder or the like to maintain confidentiality. I have. However, since the sheet on which the toner image or the like is formed cannot be reused, it is not only extremely wasteful but also requires a shredder for fine cutting.

For this reason, it has been conventionally proposed to erase a toner image formed on a sheet and reuse the sheet, that is, use the sheet again for image formation. For example, Japanese Patent Application Laid-Open No. Hei 5-289576 discloses an image erasing device that feeds a sheet on which a toner image is formed as necessary into a transport path and erases the toner image in the transport path. After erasing the sheet, the sheet is discharged to the outside, and when the sheet is reused, the sheet from which the toner image has been erased is sent to the image forming apparatus to form an image on the sheet.

However, according to the image erasing apparatus described in the above publication, an image is formed using a toner whose colorant becomes colorless by irradiating light of a specific wavelength, and the light of the specific wavelength is applied to a sheet. Irradiation is performed on the entire upper surface to erase the image. Therefore, the toner image formed on the sheet cannot be erased for an image formed with a general toner without performing development using a special toner.

On the other hand, as typified by JP-A-7-68994 and JP-A-7-68995, a processing liquid for removing toner from a sheet in order to erase a toner image on the sheet. Is applied first to make the toner image easier to peel off from the sheet, and by passing it through a heating roller, for example, the toner on the sheet is absorbed by the surface of the heating roller and removed, and the toner image on the sheet is erased. It is something to do. According to such a configuration, even if the toner is not special, the toner image can be easily removed from the sheet by applying the processing liquid for removing the toner, and the toner can be reused.

Japanese Patent Application Laid-Open No. 7-9 / 1995 discloses a method for applying a processing liquid to remove a toner image from a sheet surface.
Japanese Patent Application Laid-Open No. 2863/1995 and Japanese Patent Application Laid-Open No. 7-129045 also disclose, in particular, Japanese Patent Application Laid-Open No. 7-92883, which detects whether or not a toner image is present on a sheet and removes toner and the like. There has been proposed an image processing apparatus in which the discharge position is changed between the case where the image exists and the case where the image does not exist so as to simplify the subsequent processing.

[0008]

As described above, in a toner image erasing device provided in a conventional image forming apparatus, when an image is formed with a special toner,
Although the toner image can be erased, a general toner image cannot be erased.

Further, if a processing liquid is applied in advance to erase a toner image before erasing, a toner image on a sheet can be easily erased even if the toner is not special. Therefore, in order to erase the toner image in the image forming apparatus, a processing liquid application unit may be provided, and a device for erasing the toner image on the sheet using the removing unit may be built in the image forming apparatus.

That is, in the image forming apparatus, the sheet is fed from a portion for storing the unnecessary sheet on which the toner image is formed, and the removing liquid is applied to the toner image forming surface of the fed sheet. Thereafter, the toner image can be removed when the toner image is passed through a heating roller or the like.

However, in the prior art, a sheet from which a toner image or the like has been erased is efficiently processed so that it can be easily reused in an image forming apparatus, and the processed sheet can be reused. Is not considered at all.

In the technique described in Japanese Patent Application Laid-Open No. 5-289576, a sheet after erasing is discharged out of the apparatus or a sheet size is detected and a sheet is fed to a sheet feeding section matching the size. The point that it was configured to send in is specified. However, in order to detect the size of the sheet after erasing the image and feed the sheet to a sheet feeding unit that matches the size, the sheet passes through a specially provided conveyance path, and the conveyance path becomes large, and the entire apparatus is It tends to be larger.

Further, when a sheet from which an image has been erased is fed to a sheet feeding unit corresponding to a desired size, or when the sheet feeding unit does not exist or cannot be fed any more, the processing destination of the sheet is changed. They no longer exist and sheet jams and the like may occur.

Further, even if the image is erased, the recorded matter written on the sheet by other recording means, for example, a writing instrument other than the toner is not erased, and when the image is reused, the formed image is read. Obstacles such as becoming impossible occur. Such an obstacle occurs not only in the recorded matter other than the toner but also in a case where a staple or a punch hole for a file exists. In other words, if there is a stapled portion, the image on that portion will be performed normally, and in the punched hole, not only the image will be missing, but also the toner in the portion corresponding to the punched hole will be transferred. The sheet is transferred to a transfer device, so that the transfer device is soiled and the back surface of the next sheet is also soiled.

Therefore, it is important to make the sheet reusable when it is not always possible to use the sheet as it is if the image is erased. Not only wasn't considered at all, nor was there anything to handle them.

In view of the above-mentioned problems, the present invention provides a device for erasing an image in an image forming apparatus, and enables a process for discharging a sheet after erasing, in particular, a sheet process for effectively and efficiently reusing the sheet. It is an object of the present invention to provide an image forming apparatus according to the present invention.

It is another object of the present invention to utilize the sheet conveyance path provided in the image forming apparatus in advance, and to more efficiently and effectively process the sheet after erasing the image.

Still another object of the present invention is to provide an image forming apparatus in which the sheet can be reused more effectively and efficiently by changing the size of the sheet to an appropriate size. .

In particular, an object of the present invention is to provide a device which can minimize the trouble of a user and can efficiently reuse an erased sheet or the like.

[0020]

An apparatus for achieving the above object according to the present invention is to feed a sheet stored in a sheet feed tray and feed an image to an image forming position in order to form an image on the sheet. After forming, in an image forming apparatus that outputs the sheet after the image formation to the outside of the apparatus, an image erasing feed tray that stores the sheet on which the image is formed,
A feeding means for feeding the sheets in the image erasing sheet feeding tray, and an image erasing device arranged in a passage for feeding out the sheets fed by the feeding means and erasing an image formed on the sheets; A reading sensor for reading an image forming state of a sheet conveyed in the passage, a cutting device for cutting a sheet conveyed in the passage to a predetermined size, and the image sensor based on data read by the reading sensor. Control means for recognizing an unnecessary portion which cannot be erased by the erasing device and changing to a sheet of a predetermined size using the cutting means; and And a communication path provided for feeding the sheet reproduced to the size into the paper feed tray and storing the sheet.

According to such a configuration, when forming an image by reusing a sheet from which an image has been erased, the sheet is changed to a predetermined size and accommodated in a paper feed tray. It saves the trouble of processing.
In addition, since unnecessary portions of the sheet, on which the image cannot be erased, are removed by the cutting device and the sheet of a predetermined size is reproduced, there is no problem at all when the image is formed such that the image is missing or the formed image cannot be recognized.

Therefore, in the apparatus having the above-described configuration, when the paper feed tray includes a plurality of paper feed trays that can accommodate sheets of different sizes and can selectively feed the paper, the control unit controls the cutting device. The sheet can be controlled to be fed to a sheet feed tray corresponding to the size of the cut sheet. Therefore, the sheets reproduced in the respective sizes can be accommodated for efficient reuse, so that the trouble on the user side can be eliminated. In this case, if the size is specified on the user side, not only can all sheets be changed to the same size, but also a sheet of a frequently used size can be easily reproduced.

Further, in the apparatus having the above-described configuration,
If the control unit controls the cut portion so that the sheet size is maximized when the unnecessary portion read by the reading sensor is removed by the cutting device, waste of the reproduced sheet is reduced. Disappears. That is, it is possible to minimize the cut unreproducible portion as much as possible.

Another apparatus for achieving the above-mentioned object of the present invention is to feed a sheet stored in a sheet feed tray, and feed the sheet to an image forming position to form an image on the sheet. In an image forming apparatus for outputting the sheet after the image formation to the outside of the apparatus, an image erasing sheet feeding tray accommodating a sheet on which an image is formed, and a sheet feeding sheet in the image erasing sheet feeding tray. Feeding means, an image erasing device arranged in a passage for feeding out the sheet fed by the feeding means for erasing an image formed on the sheet, and reading for reading an image forming state of the sheet conveyed through the path A sensor, a switchback conveyance path provided in the middle of the passage for branching and reversing the front and back surfaces of the sheet, and the switchback conveyance path based on data read by the reading sensor. Control means for determining whether or not the front and back surfaces of the sheet are to be reversed by using the image erasing device, and controlling the image formed on at least one side of the sheet to be erased via the image erasing device; and And a communication path provided to feed and house the sheet from which the image has been erased to the paper feed tray.

According to the apparatus having such a configuration, the images formed on both sides or one side of the sheet can be erased as necessary, and the erased sheet can be efficiently reused. I can omit it at all. In other words, instead of aligning the image forming surfaces of the sheets on the user side and storing the sheets in the image erasing feed tray, the sheets are simply stored as a sheet bundle.
After the double-sided or single-sided image is erased as necessary, the image can be sent to the sheet feeding tray.

Therefore, in the device having the above configuration,
In the above-mentioned control means, in order to erase the image formed on both sides of the sheet, the image is formed on one side of the sheet by passing through the switchback conveyance path and presenting both sides of the sheet to the image erasing device. If it is possible to appropriately select the image erasing by presenting only the determined surface to the image erasing device for erasing, not only can the image on both sides of the sheet be erased, but also after erasing the image on only one side, The sheet can be sent to a paper feed tray for reuse. In this case, the image erased side is accommodated in the paper feed tray in an aligned state, so that when the sheet is used as a back paper copy, the image is prevented from being formed on the image forming side. It is possible to eliminate troublesome processing on the user side.

In the apparatus having the above-described configuration, if a cutting means for appropriately cutting the sheet is provided in a passage through which the sheet is fed in order to perform image erasure, the sheet is read based on the data read by the reading sensor. An unnecessary portion that cannot be erased by the image erasing device is recognized, the unnecessary portion can be easily removed by using the cutting means, and the sheet can be reproduced to a predetermined size.

Further, in the apparatus having the above-described configuration, the control means can easily recognize the position of the punched hole based on the data read by the reading sensor, and switch the position of the punched hole so as to be aligned. Punch holes can be aligned in one direction by controlling whether or not sheet reversal is performed using the back conveyance path. In this case, by controlling the conveyance of the sheet to the image forming position, the image can be formed avoiding the punch portion. Also in this case, the user does not need to realign the punched holes in the same direction.

Another apparatus for achieving the object of the present invention is to feed a sheet stored in a sheet feed tray, and feed the sheet to an image forming position to form an image on the sheet. In an image forming apparatus for outputting the sheet after the image formation to the outside of the apparatus, an image erasing sheet feeding tray accommodating a sheet on which an image is formed, and a sheet feeding sheet in the image erasing sheet feeding tray. Feeding means, an image erasing device which feeds a sheet fed by the feeding means, is disposed in a passage communicating with the image forming position, and erases an image formed on the sheet, and a sheet conveyed through the passage A reading sensor for reading the image forming state of the image forming apparatus, a conveyance path for returning the sheet passing through the image forming position to the image erasing sheet feeding tray in the same posture, and a sheet passing through the image forming position. A switchback conveyance path for feeding the sheet back to the image erasing paper tray with the front and back reversed, and an image forming surface formed on a sheet based on data read by the reading sensor. Control means for selectively passing through a transport path or a switchback transport path to return to the image erasing sheet tray, and thereafter performing image erasing processing via an image erasing device. It is characterized by having.

In particular, an intermediate tray for temporarily storing a sheet on which an image has been formed for forming an image on both sides of the sheet or forming a composite image on the same side is also used as the image erasing sheet feeding tray. By doing so, it is not necessary to separately provide a paper feed tray for image erasing, and the image erasing can be performed using the existing one provided in the image forming apparatus as it is. Further, the user does not need to arrange the image forming surfaces and store the sheets on the tray. When the storing is completed, the user can realign the image forming surfaces of the sheets in one direction. Therefore, a sheet on which an image is not formed can be used as a back paper copy by using the surface of the sheet, and can be reused after the image is erased. Therefore, since the image erasing operation can be performed continuously, the processing time for erasing the image can be reduced.

A final apparatus for achieving the object of the present invention is to feed a sheet housed in a paper feed tray, feed the sheet to an image forming position to form an image on the sheet, and form an image on the sheet. In an image forming apparatus for outputting a sheet after image formation to the outside of the apparatus, an image erasing sheet feeding tray for accommodating sheets arranged such that an image formed surface is in the same direction, Feeding means for feeding the sheets in the tray, and an image erasing device for sending out the sheets fed by the feeding means and arranged in a passage communicating with the image forming position and erasing an image formed on the sheets An image-erased sheet accommodating section for accommodating a sheet erased by the image erasing apparatus; and a minute for feeding the sheet erased by the image erasing apparatus to the image-erased sheet accommodating section. The conveyance path and whether to feed the sheet stored in the image erasing sheet feeding tray to the image forming position or to feed the sheet to the image-erased sheet storing section after passing through the image erasing device as appropriate. And control means that can be selected.

With this configuration, a sheet having an image formed on one side can be reused as it is, that is, used as a back paper copy, with a very simple configuration. When the image is erased and reused, the fed sheet is erased by an image erasing apparatus, and then the sheet is sent to an image forming position to perform an image forming process.

[0033]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a first view for erasing a toner image provided in an image forming apparatus according to the present invention.
FIG. 4 is a diagram schematically illustrating processing of a sheet after image erasing, which is the image erasing apparatus according to the first embodiment. FIG. 2 is a flowchart showing a control operation by the control means of the image erasing device in FIG. FIG. 3 is a diagram showing an example of a basic configuration of an image forming apparatus provided with an image erasing device according to the present invention, and FIG. 4 is a control flowchart thereof.

First, the basic configuration of the image forming apparatus according to the present invention will be described with reference to FIG. The image forming apparatus 1 is a digital copying machine.
As shown in the figure, a photoreceptor 2 which is a recording medium having a photoconductive layer formed on a surface rotating in the direction of the arrow, a charger 3 for uniformly charging the surface along the direction of rotation, and a charged surface. An exposure unit 4 for image exposure, a developing device 5 for developing an electrostatic latent image formed by exposure, a transfer device 6 for transferring a developed toner image to a sheet, and a cleaning device 7 for removing residual toner after transfer are opposed to each other. It is arranged.

The exposure unit 4 for imagewise exposing the surface of the photoreceptor 2 is imagewise exposed to a laser beam from a laser irradiation device 8 via a fixed reflector 9. The laser irradiation device 8 drives and controls a semiconductor laser based on read data from an image reading scanner 10 disposed on the upper side of the laser irradiation device 8 so as to generate an optical image corresponding to the read data. Irradiate the surface.

The laser irradiation device 8 is driven based on not only image data for performing recording processing based on read data from a copy document read by the scanner 10 but also image data transferred from an external device. Controlled. Therefore, image data is received from an external device such as a facsimile, a personal computer, or a word processor, and the drive of the laser unit 8 is controlled in accordance with the image data.

The scanner 10 has a first scanning unit 1 which is scanned to read an image of a document which is manually placed or automatically set on a document table 11 disposed thereon.
2 and a second scanning unit 13.
Is formed on a CCD 15 serving as an image reading element via an imaging lens 14, and the optical image is converted into an electric signal to output read data. The read data is
Further, an image processing device (not shown) generates image data for driving the laser of the laser unit 8 described above.

The first scanning section 12 includes an exposure lamp 12a for irradiating the original with light, and a reflecting mirror 12b, and runs parallel to the original table 11 at a predetermined speed V, for example. . The second scanning unit 13 includes reflection mirrors 13 a and 13 b for directing the reflected light from the reflection mirror 12 b to the above-described imaging lens 14. The vehicle is driven to travel at a speed of V / 2 in parallel along 11. Thus, the image of the document on the document table 11 is scanned line by line, and is irradiated on the CCD 15.

The document table 11 is provided with a document tray for placing a document to be read, a discharge tray for receiving the document that has been read, and the like. The documents on the document tray are fed one by one. An automatic document feeder 16 is provided for automatically setting the original on the sheet and discharging the document to the discharge tray. The automatic document feeder 16 is provided so as to be openable and closable with respect to the document table 11, and when the document is placed on the document table 11 in a closed state, an original is set on a document tray to be in an automatic feed mode. Automatically feeds and discharges the originals one by one to the original platen 11. In the case of a book-shaped original or an original that cannot be automatically fed, the original automatic feeder 16 can be opened and the original can be placed on the original platen 11 manually.

On the other hand, the sheet is fed into the image forming apparatus 1 to a transfer position where a transfer unit 5 for transferring the toner image formed on the photoreceptor 2 onto the sheet is provided.
A sheet transport system for discharging sheets to the outside of the image forming apparatus is provided. This conveyance system also includes a conveyance system for forming an image again on both sides or the same side of a sheet on which an image has been formed.

In particular, a large number of sheets are accommodated in the lower part of the image forming section of the image forming apparatus main body 1 including the above-described photoreceptor 2, charger 3, exposure unit 4, developing unit 5, transfer unit 6, and the like. Automatic paper feed trays (cassettes) 17 and 18, and an intermediate tray 19 provided on the top thereof for temporarily storing sheets having a toner image formed on one side thereof and feeding the sheets again to the image forming section. , And a manual paper feed tray 2 which is arranged so as to protrude to the right in the figure and can be manually fed.
0 is provided. Further, in the present invention, an image erasing sheet feeding tray 21 for storing a sheet on which an unnecessary toner image is formed and feeding the sheet for erasing the toner image on the sheet when necessary. Is provided.

The automatic paper feed tray 17 or 18, the intermediate tray 19 or the image erasing paper feed tray 21 can be pulled out to the front in the figure, and sheets can be stored or removed from the tray as required. You can do things freely.

The automatic paper feed trays 17 and 18, the intermediate tray 19, the manual paper feed tray 20, and the image erasing paper feed tray 21 are provided with paper feed rollers 17a and 18 respectively.
a, 19a, 20a, and 21a are provided and selectively driven and controlled. Sheets fed from the automatic paper feed trays 17 and 18 and the intermediate tray 19 are conveyed via a plurality of conveyance rollers 23 arranged on a conveyance path 22, and are conveyed via the conveyance path 22 and the manual paper feed tray 20. The sheet is fed to a registration roller 24 located further downstream of a portion where the sheet to be fed and guided by a manual conveyance path are joined, and at an image forming position, that is, before the transfer unit 6.

The registration roller 24 is connected to the automatic paper feed tray 1
7 or 18, a roller for controlling the conveyance of a sheet selectively fed from one of the intermediate tray 19 and the manual paper feed tray 20 to the transfer position in synchronization with the rotation of the photosensitive member 2. It is.

After the toner image formed on the photosensitive member 2 is electrostatically transferred by the operation of the transfer device 5, the sheet fed by the registration roller 24 is peeled off from the surface of the photosensitive member 2, and air is applied from the back surface. The sheet is conveyed on a conveying belt 25 that conveys by suction, and is guided to a fixing device 26. The fixing device 26 includes a roller 26 having a heater lamp and the like inside.
and a pressing roller 26b for pressing the sheet against the heat roller 26a.

On the discharge side of the fixing device 26, when the sheet after fixing is discharged to the outside of the image forming apparatus, or when an image is formed a plurality of times on the surface opposite to the image forming surface of the sheet or on the same surface, A switching member 2 for switching between a discharge path 27 and a re-passage 28 in order to feed the intermediate tray 18
9 are provided. The re-passage 28 is provided with a conveying roller 30 for feeding the sheet to the intermediate tray 19, and the sheet sent via the conveying roller 30 is controlled by the conveying unit 31 and the switching claw 32. The discharge is controlled to the intermediate tray 19 according to the size.

On the other hand, in the discharge path 27, a discharge processing device 34 for discharging the discharged sheet is provided so as to be opposed to the discharge processing device 34.
Is provided with a sorter 33 having a number of distribution trays 35 for distributing discharged sheets. Therefore, the sheet on which the image formation is completed is sent to necessary distribution trays, and the sheets are discharged in a state where the page order and the like are aligned on each tray.

The sorter 33 is provided with a transport belt 36 for feeding sheets to the respective trays, and a branch claw 37 disposed corresponding to each tray, corresponding to each of the distribution trays 35. And a conveyance path 3 communicating with a discharge path 27 for guiding sheets to the tray.
8 are provided. Also, at the end of the transport passage 38,
Conveyor belt 3 for distributing and discharging the above-mentioned sheets
6 or a switching claw 40 which is arranged separately from the distribution tray 35 and switches the sheet to a discharge tray 39 which is a sheet discharge destination when the sorter is not used.
Is provided. Further, in the middle of the transport passage 38,
A re-conveying path 41 for feeding the sheet again to the image forming apparatus 1 and forming an image on the surface opposite to the image forming surface of the sheet is provided, and a switching claw 42 for switching to the path.
Is arranged.

The end of the re-conveying passage 41 is connected to an intermediate passage 43 for leading to the intermediate tray 19 of the image forming apparatus 1.
Has been communicated with. The intermediate passage 43 is a passage provided in advance for forming an image on both sides of the sheet. In particular, a reversing passage 44 for reversing the sheet is provided in the intermediate passage 43 to reverse the front and back surfaces of the sheet. Corresponding to the reversing passage 44, an image-erased sheet storage section 445 for temporarily storing the sheet after erasing the image formed on the sheet in the present invention is provided. Also in the case of forming an image on both sides of the sheet, the reversing passage 44 is a passage provided in the image forming apparatus 1 in advance.

The intermediate passage 43 is provided in the image forming apparatus 1 in advance to feed the sheet to the intermediate tray 19, similarly to the re-passage 28 described above. Further, the re-transport passage 41 communicating with the intermediate passage 43 via the reverse passage 44.
Also, as described above, the passage is provided in advance, and may be provided on the image forming apparatus 1 side.

The intermediate passage 43 is provided with a branch passage 46 on the way to correspond to the automatic sheet feed tray 17 or 18.
And 47 are provided, and the branch passages 46 and 47 are provided.
Are provided with switching claws 48 and 49 correspondingly. Further, when the sheet feeding direction guided to the reversing passage 44 is reversed, the switching claw 50 for guiding the sheet to the intermediate passage 43 is disposed at a branch position between the reversing passage 44 and the intermediate passage 43. ing.

On the other hand, in the reversing passage 44, a transport roller 51 which can rotate forward and reverse to transport the sheet to the sheet storage section 45 and simultaneously transport the sheet in the reverse direction is arranged. Further, a sheet feeding roller 52 for feeding a sheet stored in the sheet storage unit 45 to the reversing path 44 and a feeding roller 53 for further feeding the fed sheet are provided. Conveying roller 51 and feeding roller 5
A sheet detection sensor 54 for detecting the presence / absence of a sheet is provided in a passage between the first and second sheets.

At the position where the sheet detecting sensor 54 is disposed, a size detecting sensor for detecting the sheet size and its direction is further provided. In particular, the sheet detection sensor 54 also serves as size detection for detecting the length of the sheet in the sheet conveyance direction according to the time of sheet conveyance in the state where the sheet leading edge is detected, and furthermore, in the direction orthogonal to the sheet conveyance direction. In order to detect the length (width), a plurality of detection sensors are arranged in that direction to form a size detection sensor.

Further, in the branch passages 46 and 47,
The fed sheets are sent to the automatic paper feed trays 17 and 18.
Conveyance rollers 55 and 56 for discharging from the upper part are provided, and flappers 57 and 58 for switching a position for carrying out according to the size and direction, that is, a position for dropping into a tray, are disposed in the middle thereof. Have been.

Next, the erasing device 60 for erasing a toner image formed on a sheet according to the present invention will be described. The image erasing device 60 feeds the sheets stacked on the image erasing tray 21 for accommodating the sheets on which unnecessary images are formed as shown in FIG. 3 or more specifically, FIG. It is arranged in a paper feed path 59 in which paper is fed by a paper feed roller 21a.

The image erasing device 60 is configured to spray and apply a processing liquid for facilitating the peeling of the toner from the sheet to the toner image forming surface of the sheet through the nozzle 61 and store the processing liquid. The processing liquid is supplied to the nozzle 61 from the portion thus formed, and is sprayed and applied through the nozzle 61. This application may be performed by bringing the sheet into contact with the absorbing member impregnated with the processing liquid instead of the nozzle 61.

The image erasing device 60 heats the toner image on the sheet surface to which the processing liquid has been applied, and presses the removing roller 62, which is a heating roller for removing the toner image from the sheet surface, and the sheet against the removing roller 62 surface. And a pressure roller 63 for removing the toner. The removal roller 62 is provided with a heater lamp 64 such as a halogen lamp inside the roller, and the heater lamp 63 controls the driving of the electric power to maintain the surface temperature of the removal roller 62 at a predetermined temperature. Will be

In order to feed the sheets stored in the image erasing sheet tray 21 to the image erasing device 60, the sheet feeding roller 21a is provided opposite to the image erasing sheet tray 21 as described above. Then, the sheet is fed into a sheet feeding path 59 in which the image erasing device 60 is arranged. Then, the sheet passing through the removing roller 62 and the pressure roller 63 is fed into the sheet feeding path 59, and is fed into the erased sheet storage section 45 via the conveying roller 65 arranged in the path. In the middle of feeding the sheet, a flapper 66 that switches the position of dropping the sheet into the sheet storage unit 45 according to the sheet size is provided.

A sheet detection sensor 67 is provided between the path between the image erasing device 60 and the conveying roller 65 for detecting the size and the direction of the sheet, and the like. It is provided so as to detect a width in a direction perpendicular to the direction.

As described above, the image erasing feed tray 21
The fed sheet is sent out to the paper feed path 59 via the image erasing device 60. The feed path 59 and the intermediate path 4 provided in the image forming apparatus 1 in advance.
3 is communicated via a sheet storage section 45 for temporarily storing the image-erased sheet and a reversing passage 44.

The structure of the image erasing mechanism in the image forming apparatus 60 is not an essential component of the present invention, but a conventionally known structure can be used as it is. For example, JP-A-7-68994, JP-A-7-6994
No. 68995, etc., which has a structure shown in FIG. 10 for applying a treatment liquid that facilitates peeling of a toner image can be used. In addition, when a toner image is rendered colorless by irradiating light of a specific wavelength as a toner at the time of development, an image erasing device irradiates the entire sheet with light of a specific wavelength. Irradiation means may be provided. For the details, the apparatus described in JP-A-5-289575 may be applied as it is.

In the configuration of the image erasing device 60 described above,
Next, the image erasing operation will be described with reference to the control flowchart of FIG. Further, the image forming apparatus 60 itself can be operated by a power source different from that of the image forming apparatus. Therefore, when the user wants to operate the image erasing device 60, the power is turned on (ON).

When the power is turned on (n1), the operation starts, and the heater lamp 64 of the removing roller 62 is driven (n).
2) That is, power is supplied (ON). Then, it controls (n3) that the surface temperature of the removing roller 62 becomes a temperature (T) at which the toner can be removed, and if it is confirmed that the temperature has risen to that temperature, a predetermined time (t) is set by the timer.
Is started (n4). Then, it is confirmed that the sheet is stored in the image erasing leaving sheet feeding tray 21 (n
5) Then, the accommodated sheets are sequentially fed one by one at predetermined intervals one by one through the feed roller 21a (n6), and the toner is erased by the image erasing device 60 ( n7) is performed.

In the toner erasing operation, the processing liquid for removing the toner is applied to the toner image surface of the fed sheet through the nozzle 61 and the like, and the removing roller 62
The toner is removed from the sheet between the pressure roller 63 and the pressure roller 63 and adheres to the surface of the removal roller 62. This removal roller 62
The toner adhering to is removed by the cleaning means,
The removal roller 62 always faces the image surface of the sheet in a clean state. The sheet from which the toner image has been removed in this way is conveyed by the conveying roller 65 to the erased sheet storage unit 4.
5 and temporarily stored (n8).

On the other hand, if there are no more sheets stacked on the image erasing paper feed tray 21, the image erasing device 60 is operated after a predetermined time (t) (n9) to end the removing operation.
Is automatically turned off (n10).

The basic configuration of the image erasing device provided in the image forming apparatus according to the present invention described above has been described. Hereinafter, each embodiment including the processing of a sheet after image erasing according to the present invention will be described. In particular, in the present invention, the sheet after erasing the toner image is efficiently reused. Therefore, a reusable sheet from which an image has been removed is sent to the image forming unit. In addition, the sheet can be reused by being classified according to the sheet size. Further, the image erasing device can efficiently perform the image erasing, and at the same time, can increase the processing capacity and eliminate unnecessary erasing operation.

(First Embodiment) FIG. 1 shows an image erasing apparatus 60 according to the present invention, which includes an apparatus for processing a sheet after erasing an image and removing unnecessary portions. This will be described in detail with reference to FIG. FIG. 1 is a schematic diagram showing the basic concept of the first embodiment of the present invention.

In FIG. 1, the portions denoted by the same reference numerals described in the image forming apparatus of FIG. 3 play the same role. That is, the image erasing feed tray 21 for erasing an image is used.
, A large number of sheets are stacked, and the sheets are stacked with the image forming surface facing down, and the stacked state is detected by a sheet detecting unit (not shown).

The image erasing paper feed tray 21 is provided with a corresponding paper feed roller 21a.
The sheet is fed one by one from the uppermost sheet by a feeding means composed of the above. The fed sheet is fed one sheet via a feed roller 21b and a separation roller 21c, and sent out to a transport path 69 indicated by an arrow. A plurality of transport rollers (not shown) are arranged in a transport path (path) 69 indicated by an arrow, and a transport distance between the transport rollers is set to a width that can transport a sheet of a minimum usable size. That is, if the minimum size is B5, an interval at which a sheet of that size can be conveyed,
For example, a plurality of transport rollers are arranged at an interval of less than 180 mm.

The feed roller 21b and the separation roller 21
The close contact type sensor 70 is arranged so as to face the sheet outlet between the sensor 70 and the sheet outlet c. The contact type sensor (reading sensor) 70
Is a sensor for reading an image formed on both sides of the sheet, and can read an image similarly to the CCD sensor 15 described with reference to FIG.

A first cutting device 71 and a second cutting device 72 for cutting a sheet into a predetermined size according to the present invention are arranged in the conveying path 69 indicated by the arrow, in addition to the conveying rollers described above. Further, an image erasing device 60 for erasing an image of a sheet cut to a desired size is provided. The sheet from which the image has been erased is sent to a paper feed tray of various sizes corresponding to the size of the sheet via the transport path 69. Therefore, the transport path 69 is provided with a communication path that is fed from the paper feed tray and communicates with the transport path.

The paper feed trays are the paper feed trays 17 and 18 shown in FIG. 3. Particularly, the paper feed tray 18 is a tray for storing B5 size paper, and the paper feed tray 17 is an A4 size tray. Further, the tray 45 is used as a sheet storage unit for temporarily storing the image-formed sheets described with reference to FIG.

The first and second cutting devices 71 and 72
Is a conventionally known cutting device, in particular, the first cutting device 71 is to cut the sheet in a direction perpendicular to the conveying direction, the upper cutting blade 71a is provided to be able to move up and down, By descending, the sheet is cut at once with the fixed blade 71b. Also, the second cutting device 72
Is for cutting a sheet along a conveying direction by a cutter unit (slitter) 72a which rotates along the sheet conveying direction, and the cutter unit 72a is movable in a direction orthogonal to the sheet conveying direction. Is provided. Thus, the sheet can be cut to a predetermined width at an arbitrary position in the sheet width, that is, a direction orthogonal to the sheet conveying direction.

The control operation of the control means for controlling sheet conveyance, image erasure, and sheet cutting in the above configuration will be described with reference to the control flowchart shown in FIG.

First, when an operation for erasing an image is started, the control means checks whether or not a sheet is present in the image erasing sheet feeding tray 21 and then checks the sheet feeding roller 21a.
Then, one sheet is fed to the transport path 69 via the feed roller 21b and the separation roller 21c. In the fed sheet, the size of the fed sheet is simultaneously detected at the same time when the image formed by the close contact sensor 70 is read (n1).
1) is done. In other words, in the direction (sheet width) orthogonal to the direction in which the fed sheet is conveyed, the control means can easily confirm both ends of the sheet based on the image read data, and at the same time, easily read the read data. You can see the width. In the transport direction, the tip ends with the sensor 70.
Can be confirmed, so that the length can be confirmed by the transport speed and time. This is well known.

If the images formed on both sides of the sheet are read by the contact type sensor 70,
It is confirmed whether there is an image other than the toner image, for example, a seal image or a handwritten image (n12). For example, an image such as a seal can be easily recognized by a density difference or the like. In addition, a color sensor can easily recognize a color other than the color of the toner image.

Here, a seal or other handwritten image cannot be erased. In addition to the image, a punched hole and a missing portion of the sheet are confirmed in the above step n12. The presence of the missing portion causes image loss or the like when the sheet is reused. In this manner, it is possible to easily recognize from the data read by the contact type sensor 70 whether or not there is an unnecessary portion for reuse.

If there is a defect in the fed sheet, that is, a portion where the image cannot be erased or a portion such as breakage exists,
If the sheet is cut to a standard size in order to increase the efficiency of reuse, it is determined whether or not the above-described problem is eliminated. That is, it is confirmed whether or not the sheet can be reused after the image is erased by cutting the unnecessary portion of the sheet (n13). In this confirmation, if the unnecessary parts cannot be removed even after cutting and cannot be reproduced as a standard size sheet,
Without operating the first and second cutting devices, the sheet is directly discharged to the discharge tray 73 via the path shown by the broken line (n1
4)

At step n13, unnecessary portions are cut,
If it is confirmed that the sheet can be reused, the fed sheet is sent to the first and second cutting devices 71 and 72 and cut into a predetermined fixed size. In this case, in most cases, a seal or a missing portion exists at the end of the sheet. However, if there is an image that cannot be erased at the center of the sheet, it may not be possible to reproduce a fixed-size sheet by removing that portion. However, in the case of a sheet of a maximum size, for example, A3, on which an image can be formed by the image forming apparatus, it is possible to reproduce a sheet of a standard size of B5 by cutting unnecessary portions.

When the first cutting device 71 can reproduce a sheet of a fixed size, the cutting blade 71a is controlled to lower so as to remove an unnecessary portion of the conveyed sheet.
In other words, if there is an unnecessary portion at the leading end of the conveyed sheet, the leading end is cut in a state where the leading end has passed the position of the predetermined length cutting blade 71a in order to cut the unnecessary portion,
The length of the sheet in the conveying direction is cut to, for example, A4 or B5.

Then, as for the width of the sheet, the slitter 72a is moved in the direction of the rotation axis of the conveying roller by the second cutting device 72 so as to match the width of the standard size A4 or B5 so that one side end portion is moved. Cut it. At this time, if there is an unnecessary portion at one side end of the sheet, when the portion is cut and reused, the unnecessary portion does not exist and a clean state is obtained.

If unnecessary portions exist on both sides of the conveyed sheet, two slitters 72a for cutting both sides are provided so as to be moved separately in order to cut both sides. Can be dealt with.

When the sheet is changed to a desired standard size and cut (n15) as described above, and the sheet is reproduced for reuse, the cut sheet is transported to the image erasing device 60 by the transport roller. Sent through. At this time, the toner image is removed from the sheet as described in the image forming apparatus of FIG. 3 (n18), and it is confirmed whether or not the sheet feed tray 17 or 18 of a size that can be accommodated exists (n19). The paper is fed to the matching paper feed tray. However, if there is no tray that stores sheets of the same fixed size, the sheet is sent to the sheet storage unit 45 where the image has been deleted. For example, paper tray 1
Reference numerals 7 and 18 denote trays for storing B5 and A4 sheets in the horizontal direction (shorter length direction), and when storing the sheets by conveying the sheets in the vertical direction, the sheets have the same size as other sheets. The sheet is stored in a sheet feed tray or the like.

On the other hand, if there is no loss or a part in which the image cannot be erased on the sheet in step n12, it is confirmed whether or not the sheet is divided into two (n16). This is effective when the user frequently uses a sheet having a smaller size than a sheet having a larger size. The user instructs in advance whether or not to divide into two. This means that the maximum size A3 becomes two A4 size sheets and the B4 size sheet becomes two.
The sheet is cut into n sheets of B5 size (n17). However, if the two-split instruction is not given, the cutting operation is not performed by the cutting devices 71 and 72, and the sheet is sent to the image erasing device 60 in step n18 to erase the toner image formed on the sheet. Is performed.

If an instruction to perform two divisions is given, the first
In the cutting device 71, the sheet is cut at the timing when the sheet is fed to a half position of the cut portion (n
17). In this case, in order to generate a gap between sheets, the driving of the conveying rollers arranged before cutting is stopped for a certain period of time at the timing of sheet cutting, and then the driving of the stopped conveying rollers is restarted. The sheet can be fed to the image erasing device 60 at the sheet interval.

Each of the sheets cut in two in this manner is sent to the paper feed tray 17 or 18 of a desired size after erasing the image. Also,
If there is no sheet tray 17 or 18 of a desired size, the sheet is fed to the image-deleted sheet storage unit 45. When the user erroneously places a sheet on which an image has not been formed on the image erasing paper feed tray 21, the state is confirmed by the contact type sensor 70. Therefore, such a sheet can be fed to the corresponding paper feed tray 17 or 18 without performing the cutting and image erasing operations.

As described above, when the sheet on which an image is formed is to be used again, if there is an unnecessary portion during image formation, that portion is passed through the first and second cutting devices 71 and 72. The fixed-size sheet that has been removed and reproduced is stored in the paper feed tray 17 or 18. During the image forming operation, the paper feed tray 17 or 18
Is selected, and a sheet of a desired size can be fed from the paper feed tray to the registration roller 24 disposed in front of the transfer device 6 which is the image forming position of the image forming apparatus 1 main body. Therefore, it is possible to minimize the trouble of reusing the unnecessary sheet on which the image is formed on the user side.

Here, the first and second cutting devices 71, 7
Unnecessary portions removed at the time of cutting at 2 are collected in a collection box (not shown). In this case, a collection box is arranged corresponding to the cutting devices 71 and 72. For example, the cutting device 71
As for the collection of the unnecessary portion removed by the above, since the unnecessary portion becomes shorter than the interval between the transport rollers arranged at the interval capable of transporting the sheet of the minimum size, the unnecessary portion falls to the lower portion without being fed to the next transport roller. Therefore, if a lower guide for guiding the sheet to the downstream transport roller is provided so as to be inclined upward in the direction of the downstream transport roller, unnecessary portions are guided along the guide, and the transport force is reduced. Is released in the middle, falls in the opposite direction, and is collected in the collection box.

Further, with regard to the unnecessary portion removed by the second cutting device 72, if the lower guide for guiding between the conveying rollers is set to be equal to or smaller than the minimum sheet width, the cut unnecessary portion will be located on the downstream side. Is not guided to the transfer roller, and is collected as it is in the collection box.

According to the apparatus having the above-described configuration according to the present invention, when a stamp, a handwritten memo, or the like is present at the time of reproduction as a copy sheet, this portion is removed to make the sheet a small-sized sheet. Can be played. in this case,
By using the reproduced sheet as a sheet having a size as large as possible, unnecessary portions to be cut are not few and the efficiency of reuse is increased. Similarly, a sheet having a punched hole can be reproduced as a slightly smaller sheet by removing the portion. Further, even if the copied sheet is poorly handled and partially missing (torn), it can be reproduced as a sheet one size smaller than the sheet by removing the portion.

In such a case, according to the present invention, it is further checked whether or not the size of the removed sheet can be reproduced as a frequently used fixed-size sheet. The paper is fed to the paper feed tray 17 or 18. Therefore, the sheet that the user intends to reuse can be used more efficiently. In addition, since the toner image is erased after the unnecessary portion is cut, it is necessary to erase the unnecessary portion. Therefore, not only the processing speed is increased, but also the processing liquid for removal is reduced. Become.

When some users do not need many large-size sheets but need many small-size sheets, the user can specify small-size sheets, so that the user can easily use the sheets. It can also be cut into small size sheets for playback. For example, A3 to cut
Cutting the size of the sheet into B5 sheets would be very wasteful.
If the size is changed to a sheet or reproduced into two B5 size sheets, waste can be eliminated and resources can be effectively used.

(Second Embodiment) The first embodiment described above is an example in which a toner image is formed on one surface of a sheet and the toner image is erased. As described above, not only the toner image is formed on only one surface, but also the toner image may be formed on the front or back of the sheet, or both sides of the image erasing paper feed tray 21. When the toner image is formed in such a manner, the image may not be able to be erased by the apparatus of FIG. Therefore, this second
In the embodiment, an example is presented in which an image can be erased even when an image is formed on any sheet surface.

Therefore, on the user side, it is only necessary to store the image forming surfaces formed on the sheets in the image erasing paper feed tray 21 in a mixed state, and it is possible to save the trouble of re-aligning and storing the sheets.

FIG. 5 is a schematic diagram showing the image erasing in the second embodiment. FIG.
4 is provided on the discharge side of the image erasing device 60, and is greatly different. In this example, means for cutting a sheet to a desired size is omitted. 1 is a switching unit that can store sheets of various sizes and feeds the sheets to the sheet feeding trays 17 and 18 and the sheet storage unit 45 that can feed the sheets.

That is, in the switchback transport path 74,
A forward / reverse transport roller 75 that can switch-back transport the sheet is separately provided. By passing through the transport roller 76 after passing through the switchback transport path,
The paper is fed from the image erasing paper tray 21 by a paper feeding roller 21 a or the like, and then joins a path toward the image erasing device 60 via the contact type sensor 70.

The switching device 77 for feeding the paper to the paper feed trays 17 and 18 and the like is provided with transport means having an endless belt 77a stretched between rollers,
Switching members 78a-78 arranged corresponding to 7, 18, etc.
c. Accordingly, the switching members 78a to 78a
8c is selectively driven to position the sheet as shown in the figure when the sheet is fed into or out of the paper feed tray. Then, when the switching member is not selected, although not shown, it is positioned inside the belt 77a. Therefore, the sheet is selectively fed to the paper feed tray, or sent out from the paper feed tray to a transport path facing upward as needed. The sheet fed from the sheet feed tray is sent to a transport path in an upper direction, and is sent to a registration roller 24 of the image forming apparatus 1.

The above configuration will be described with reference to the control flowchart shown in FIG. Particularly, in the apparatus shown in FIG. 5, the upper surface is described as the front surface in a state where the sheet is placed on the paper feed tray 21. However, it does not matter whether or not an image is formed on the sheet surface.

When the image erasing operation is started, if the detecting means (not shown) detects that an image erasing sheet is stacked on the image erasing sheet feeding tray 21, the sheet feeding roller 2
1a is operated, and one sheet is sequentially fed from the uppermost sheet (n30). The fed sheet is checked whether an image is formed on its front and back surfaces, and at the same time, as described with reference to FIG. 2, the size of the sheet is set in the transport direction (length) and the width of the width orthogonal to the transport direction. Check (n3
1).

Whether or not an image is formed on both sides of the fed sheet is checked in the next step n32, and if no image is formed, the next first and second cutting devices 71 and The switching device 7 does not perform the cutting operation at 72.
7, a paper feed tray 17 or 18 of a desired size,
Further, a storage unit 45 for storing sheets of other sizes.
(N33).

If it is confirmed that an image is formed on the front and back surfaces of the sheet, it is confirmed in step n34 whether or not an instruction for only one-side processing has been given. This is instructed when the user uses a sheet on which an image is formed on one side and forms an image using a surface on which no image is formed. This means that if one side of the sheet is blank,
Since the image can be formed using the surface, the user can select the image. This is referred to below as backing paper copy.

Thus, wasteful processing when no image is formed on both sides of the sheet, that is, processing for erasing the toner image formed on the sheet is minimized, and the sheet can be reused efficiently. This makes it possible to speed up the image erasing operation.

Therefore, if the user has instructed the blank state on only one side, it is confirmed whether images are formed on both sides of the sheet (n35). In this confirmation, whether or not an image is formed on both sides of the sheet is checked in advance by the contact type sensor 70 in step n31. Therefore, when the image is not formed on both sides, the process proceeds to step n36, and it is confirmed whether or not the image is formed on the surface of the sheet. If an image is formed on the surface of the sheet, the switchback conveyance path 74
After the sheet is guided and the front and back sides of the sheet are reversed, the sheet is conveyed by the conveying roller 76 and sent to the switching device 77 side without performing the image erasing operation by the image erasing device 60, and step n39 is performed. Is performed.

If no image is formed on the surface, the image passes through the image erasing device 60 as it is.
It is sent to the switching device 77 without performing the operation by 0. Then, the sheet is sent out to the sheet feed tray 17 or 18 or the like corresponding to the sheet size detected in step n31 and is temporarily stored (n39).

On the other hand, when images are formed on both sides of the sheet, the sheet sent to the image erasing device 60 is subjected to an image erasing process to erase the image on the sheet surface (n38). Thereafter, the sheet is sent out to the sheet feed tray 17 or 18 having the same size via the switching device 77 described above.

In a state in which the sheet after the image erasure is stored in the sheet feeding tray 17 or 18 or in a state where the image is formed on one side and the image is not erased, the image is formed on all the sheets. Not side up and housed. Therefore, when the sheet is fed from the sheet feed tray 17 or 18 and sent to the registration roller 24 of the image forming apparatus 1, the sheet is sent with the surface on which the image is not formed facing upward. However, when the fed sheet is inverted and fed to the registration roller 24, the switch is set so that the sheet is fed to the feed trays 17 and 18 with the surface on which the image is not formed facing down. What is necessary is to perform the reversing operation selectively using the back conveyance path 74.

Next, when the toner images on both sides of the sheet are erased in step n34, it is confirmed whether or not an image is formed on the sheet surface (n40). When an image is formed on the sheet surface, the image erasing device 60 is used as it is.
, An image erasing process (n41) is performed. If no image is formed on the sheet surface, the image is not erased by the image erasing device 60 as it is, or after the image is erased in step n41, whether the image is formed on the back surface of the sheet. Is confirmed (n42).

If it is confirmed that an image is formed on the back surface of the sheet, the sheet passing through the image erasing device 60 is guided to the switchback conveyance path 74 in order to reverse the front and back surfaces of the sheet. , Sheet inversion processing (n4
After performing 3), the image is sent to the image erasing device 60 again,
An image erasing process (n44) for the back surface of the sheet is performed. The sheet after the image erasing process is guided to the switching device 77.

However, if no image is formed on the back surface of the sheet, the sheet is left as it is in the image erasing device 6.
Through 0, the image is guided to the switching device 77 without performing the image erasing process. The sheet guided to the switching device 77 is selectively sent to the various paper feed trays 17 and 18 according to the size detected in advance in step n31 and is stored (n45).

As described above, the control means for processing a sheet in the apparatus shown in FIG. 5 performs control according to the control flow shown in FIG. By performing the image erasing process under this control, the image erasing process can be omitted when both sides are blank. Further, when images are formed on both sides of the sheet, by selecting whether to erase the images on both sides or to erase one side, the user has a wider selection range. In this case, when the single-sided image erasing is selected, whether or not to perform the image erasing process can be determined by confirming the presence or absence of the image formed on the sheet, so that there is no need to uselessly perform the image erasing process. .

Here, a switchback transport path 74 for reversing the front and back of the sheet is provided. This switchback transport path is an essential element in the duplex copying function in the image forming apparatus. The path can also be used as a switchback transport path for duplex copying.

In the case of performing back paper copy using a sheet having an image remaining on one side, a paper feed tray dedicated to the back paper is separately provided, and the sheet with the image erased is accommodated in the paper feed tray dedicated to the back paper. By doing so, it can be used again for backing paper copying, and can be used separately from double-sided blank paper, which is very convenient. In this case, if necessary, a sheet can be fed from the back paper copy-dedicated paper feed tray to the image erasing device 60, and the image-erased sheet can be fed to the blank paper-dedicated paper feed tray 17 or 18. With such a configuration, normally, a copy process to a blank sheet and a back paper copy process can be selected, and when the image forming apparatus 1 is not used, the sheet in the back paper copy-dedicated paper feed tray is transferred to the image erasing apparatus 60. By clearing the image and feeding it back to the blank paper tray, the usage rate of newly replenished sheets on the user side can be reduced, reducing waste and reducing environmental costs. effective.

In the second embodiment, the image is read by the contact type sensor 70 and the size is detected. However, as described in the first embodiment, the image is erased in the image. Unnecessary unnecessary portions can be removed and the sheet can be regenerated to the minimum necessary size, and the sheet can be reused. This example is shown in FIG. In FIG. 7, the image erasing device 60 is connected to the switchback conveyance path 7.
4, the first and second cutting devices 71 and 72 may be provided on the transport path that is fed from the image erasing sheet feeding tray 21 by the sheet feeding roller 21a or the like. Thus, after the unnecessary portion is removed, an image erasing process is performed, and the image can be stored in the sheet feed tray 17 or 18 or the like that matches the size after the removal of the unnecessary portion.

(Third Embodiment) In each of the embodiments described above, after erasing an image (toner), the image is sent to a sheet tray of a desired size, and a sheet is formed again from the sheet tray. Is carried out to the image forming position.

Further, in the second embodiment, the image is efficiently erased particularly when images are formed on both surfaces. When the sheet having the holes is reused, the formed image is lost. The user does not always place the punched holes on the image erasing tray 21 with the forming positions in the same direction. As a result, the punches are not aligned, and a missing portion of the image occurs as described above.

Therefore, if the directions of the punch holes are aligned, it is possible to shift the formed image to eliminate missing images. In this embodiment,
The inconvenience caused by such punch holes is eliminated, and the sheet from which the image has been erased can be reused more efficiently.

In this embodiment, the control operation of the control means will be described with reference to a control flowchart shown in FIG. 8, taking the apparatus shown in FIG. 5 as an example.

In order to perform image erasing, sheets are sequentially fed one by one from the image erasing feed tray 21. At the same time as the contact type sensor 70 reads an image in accordance with the feeding, the size is checked (n52). And
Based on the read data, a portion other than the image, that is, an opening of the sheet, particularly a punched hole portion is checked (n53). In this case, it is assumed that a punch hole exists at the leading end or the trailing end of the sheet.

Then, it is checked whether or not an image has been formed on the front and back surfaces of the sheet (n54). If an image exists, it is next checked whether or not an image has been formed on both sides of the sheet (n54).
55). When images are formed on both sides of the sheet, the image on the surface of the sheet is first subjected to an erasing process (n56) through the image erasing device 60, and then the sheet is guided to the switchback conveyance path 74 to be turned over. (N57), the sheet is guided to the image erasing device 60 in order to erase the image on the back surface of the sheet again. The image on the back surface of the sheet is erased by the image erasing device 60 (n58).

If no image is formed on both sides, that is, if an image is formed only on one side, it is checked whether an image is formed on the surface of the sheet (n59). If an image is formed on the sheet surface, the image on the sheet surface is subjected to image erasing processing (n60) by the image erasing device 60. If an image is formed on the sheet back surface, the process proceeds to step n57. Image erasing device 6
At 0, the front and back surfaces of the sheet are reversed via the switchback transport path 74 without performing the image erasing process, and the image erasing process on the back surface of the sheet is executed at step n58.

After erasing the image formed on both sides of the image formed on the sheet as described above, or the image formed on the front surface or the back surface of the sheet, the existence state of the punch holes of the conveyed sheet is confirmed ( n61) is performed. This confirmation
In step n53, the presence of a punched hole is checked based on the read image data, and the presence or absence of the hole is confirmed. If there is no punch hole, the sheet is fed to a sheet feed tray having no punch hole, for example, the sheet feed tray 17.

If it is confirmed that a punched hole exists, it is checked (n63) whether or not the leading edge of the sheet to which the punched hole is conveyed is determined. , A paper tray with punch holes
For example, it is sent to the paper feed tray 18 (n64). Also,
If the punched hole is not at the front end but at the rear end, the sheet is guided to the switchback conveyance path 74 for reversing the front and back surfaces of the sheet, and after the reversing process (n65), the sheet is fed to the above-described sheet feeding tray 18. (N64).

As a result, the sheet tray 17 accommodates reusable sheets from which images have been deleted and which have no punch holes. Then, the sheet from which the image with the punched hole has been erased is accommodated in the sheet feeding tray 18, and the punched hole coincides in a state where the sheet is accommodated. Therefore, sheet conveyance control can be performed so that an image is not formed in the punched hole portion.

In the processing control of the sheet shown in FIG. 8, the case where the punched hole exists at the leading end or the trailing end has been described. In order to align the punch holes, the direction of forming the punch holes can be aligned by rotating the sheet in the conveying direction by 90 ° and performing a reversing process as necessary.

(Another Development According to the Embodiment of the Present Invention) FIG.
Is an image forming apparatus 1 according to the present invention.
FIG. 3 is a cross-sectional view illustrating the image forming apparatus in a state where the image forming apparatus is prepared for the first embodiment.
In particular, it is important to efficiently perform the image erasing process when the image forming surfaces are not stacked on the image erasing paper feed tray 21 in the same direction. That is, the image erasing process is much slower than the speed at which the sheet is simply conveyed.
Therefore, when the image forming surfaces do not match, the time for the processing becomes extremely long, and the power consumption is wasted.

That is, to erase an image, the removal roller 62 of the image erasing device 60 is controlled to be heated to a predetermined temperature. In this state, when the image is not erased, the power consumption is wasted. Therefore, in this embodiment, the image erasing process can be continuously performed at once.

For this purpose, in FIG. 9, an intermediate tray 19 for forming images on both sides of a sheet is used as a sheet feeding tray 21 for erasing images. The intermediate tray 19 sequentially feeds sheets from below. The fed sheet is fed to a conveyance path 22 for performing image formation, is guided to a re-passage 28 via a registration roller 24, a transfer position, and a fixing roller 26, and is not turned upside down. The sheet is sent to the intermediate tray 19 via a transfer path 79 for feeding the intermediate tray 19 or a switchback transfer path 74 for reversing the front and back surfaces which performs the same function as the switchback transfer path described with reference to FIG.

At the position where the sheet is fed from the intermediate tray 19,
A contact sensor 70 is provided, and an image erasing device 60 according to the present invention is provided downstream of the contact sensor 70.

In order to erase the image, the intermediate tray 19 is pulled out, the sheet on which the toner image is formed is stored in the intermediate tray 19, and is mounted on the image forming apparatus 1 body.
Thereby, the state where the sheet is placed on the intermediate tray 19 is detected. Therefore, when the image forming apparatus is set to the image erasing mode, one sheet placed on the intermediate tray 19 is sequentially fed from the bottom. In the fed sheet, first, the contact type sensor 70 detects any of the surfaces on which an image is formed.

As a result of the detection, if the image forming surface is on the upper side, that is, if the image forming surface is the upper side, the sheet is transferred through the image erasing device 60 to the transport path 22, the transfer position, and the fixing device 26.
And is carried out to the top of the intermediate tray 19 in the same posture. If it is detected by the contact type sensor 70 that the image forming surface is formed on the lower side, that is, on the back surface of the sheet, the sheet passes through the fixing device 26, passes through the switchback conveyance path 74, and is transferred to the intermediate tray 19. It is carried out from the paper feed side. Therefore, the intermediate tray 19 is sequentially carried out and stored from the uppermost portion with all the image forming surfaces facing upward.

The above-described operation is repeated, and all the sheets stored in the intermediate tray 19 are sent out in advance, and the circulation sensor is detected in a state where all the circulating conveyance returning to the intermediate tray 19 is performed again. A well-known sensor is used as the one-round sensor.

If the one cycle sensor detects that all the sheets have been circulated and returned to the intermediate tray 19, the image erasing operation is started at this point. In this case, all the sheets placed on the intermediate tray 19 make one circulation,
Since the image forming surfaces are all aligned on the upper side, the image erasing device 60 can continuously perform the image erasing operation.

The sheet from which the image has been erased passes through the transfer position and is discharged as it is to the discharge tray 80 after passing through the fixing device. Can be selectively discharged.

For this purpose, a sheet conveying means 85 is provided corresponding to the sheet storage sections 81 to 84, and the switching members 86a to 86d are opposed to the sheet storage sections 81 to 84 of the conveyance means 85. It is arranged. Further, a switching claw 87 for switching a path through which the sheet having passed through the fixing device 26 is sent to the discharge tray 80 is provided, and the sheet is selectively switched to the discharge tray 80 side or the conveying means 85 side.

Accordingly, the sheet from which the image has been erased is discharged to the sheet storage units 81 to 84 corresponding to the size of the sheet, so that the user does not need to classify the sheet. Further, the sheets from which the images have been erased are stored in the sheet storage units 81 to 81.
If the size does not match the size of 84, the sheet is discharged to the discharge tray 80 or sent back to the intermediate tray 19.
In particular, regarding the size of the sheet to be fed back, it is convenient to make the sheets the same size. That is, the sheet returned to the intermediate tray can be reused as it is as a sheet for image formation.

If the sheet after the image erasure is in the intermediate tray 1
In the case where it is not accommodated in the intermediate tray 9, the intermediate tray can be used as it is for the double-sided image or image synthesis.

Here, among the sheets on which images are formed on the front and back surfaces of the sheets using the intermediate tray 19, all the placed sheets are circulated and conveyed in order to align the image forming surfaces of the sheets. The sheet is selectively inverted. At this time, if the user desires to use the sheet as a back paper copy,
In No. 9, the sheet is accommodated in a state where the image surface is aligned upward, so that the sheet can be used as it is as a back paper copy. Therefore, it is possible to save the user the trouble of realigning the image surfaces, and at the same time, the image forming surfaces can be aligned and accommodated without being mistaken.

When the intermediate tray 19 is used as a paper feeding tray for backing paper copy, if there is no sheet for the backing paper, a sheet of the same size as this is fed from the normal paper feeding tray 17 or 18. Paper can be fed continuously. Conversely, if there are no more white sheets (sheets with no image on both sides) fed from the feed tray 17 or 18, a sheet for back paper copy of the same size is placed in the intermediate tray 1.
9, it is necessary to prohibit the paper from being fed. This is for the case where the user wants to form an image on a white sheet. If the user switches to a sheet for back paper copying in the middle, it is possible to save the trouble of deleting the unnecessary copy sheet again.

In FIG. 9, the sheet is returned to the intermediate tray 19 via the image forming section and the fixing device 26 in order to erase the image. At this time, in the image forming unit, only the photoconductor 2 is rotated so that the image is not formed, and other devices related to the image formation, for example, the developing device 5 and the transfer device 6 may be inoperative. However, the fixing device 2
In No. 6, heating is controlled to such a temperature that the toner melts and is fixed on the sheet in order to start the image forming operation. When performing the image erasing operation in this state, if the operation of the fixing device 26 is stopped, that is, if the heating source is stopped, the temperature gradually decreases. When the toner on the sheet is melted during the lowering, the sheet may be wound around the heat roller 26a or the pressing roller 26b due to the viscosity of the melted toner.

Therefore, in the fixing device 26, if the heating is controlled to a temperature higher than the temperature at which the fixing can be performed, the viscosity at that time is reduced even if the sheet is melted into the toner, so that the sheet can be prevented from winding. Also, if the temperature is lowered to a temperature at which the toner on the sheet does not melt, the sheet can be prevented from being wound. In particular, when erasing an image, it is preferable to operate the fixing device 26 in a state where the temperature of the fixing device 26 is lowered in order to reduce waste of power consumption. Therefore, by using a blower or the like for exhausting the fixing device 26 to make a cooling effect, particularly by allowing a large amount of air to flow through the fixing device 26, the temperature can be immediately lowered to a predetermined temperature or lower after the operation of the fixing device 26 is stopped.

Further, as the image erasing device 60, in the embodiment of the present invention, an example has been described in which the image is erased by removing the toner image on the sheet. However, instead of such an erasing device 60, there is an image forming apparatus that forms an image with toner itself using light erasing toner and erases an unnecessary image on a sheet by irradiating light of a specific wavelength. . For example, a toner described in JP-A-5-289576 is used to erase a toner image on a sheet formed with the toner.

Here, the problem is that even if the toner image is erased, the toner image is not removed, so that only the toner remains and becomes colorless, and the toner resin remains attached to the sheet. Therefore, if the white image is viewed closely, it can be recognized artificially.

For this reason, in order to make it impossible to recognize the colorless image remaining on the sheet, it is not necessary to first perform the image erasing operation, but to attach the erasable toner to the entire sheet with a specific light, and to fix the image after fixing. If the toner image formed on the entire surface of the sheet is irradiated with specific light to perform the erasing process, the image cannot be recognized if the image is guided to an image erasing device. If an image is formed in this state, the previous image becomes unrecognizable, and security can be maintained even if this sheet is taken out.

If the image on the sheet is a character, the character can not be recognized even if a slightly large dot-shaped toner image is adhered to the character portion without adhering the toner to the entire surface of the sheet. . In this way, a large amount of toner consumption can be saved. Moreover, even if a random pattern toner image is formed on the entire sheet, the original image cannot be recognized.

As described above, when a random pattern or a dot-shaped toner image is formed, it can be easily performed in a digital copying machine or the like. That is, some random patterns are stored in advance, and they can be selected and easily formed on a sheet.

On the other hand, in FIG. 10, the user can select whether to use a sheet on which an image is formed on only one side of the sheet as a back sheet copy or to use the sheet as a white sheet after erasing the image. It was made.

In FIG. 10, the same parts as those in FIGS. 9 and 3 are denoted by the same reference numerals, and the operation and function are the same. As shown in the figure, a sheet on which an image is formed only on one side is stacked on the image erasing sheet feeding tray 21 with the image forming side facing up on the user side. As described above, the sheet feeding tray 21 can be pulled out to the front in the drawing, and sheets can be easily placed on the tray in the pulled-out state. The sheet placed on the image erasing sheet tray 21 is fed one sheet from the lowermost portion by a sheet feeding roller 21a or the like, and then passes through the image erasing device 60 to the registration roller 24 in front of the image forming unit. It is provided so that it can be sent to.

[0148] Above the image erasing tray 21, there is provided an accommodating section 45 for accommodating a sheet after the image erasing. The image-deleted sheet storage unit 45 is configured to sequentially feed sheets from the bottom of the stored sheets via a sheet feed roller 45a, and to feed the sheet to the registration rollers 24 before the image forming unit. The sheet fed from the image erasing paper tray 21 is branched after passing through the image erasing device 60, and can be fed via a branch conveyance path 88 that communicates so as to be carried out from the upper portion of the sheet storage unit 45. It has become.

In the configuration shown in FIG. 10, when a user places a sheet having an image formed on the sheet surface on the image erasing paper feed tray 21, image formation (back paper copy) is performed using the sheet. Select whether to perform. When making a back paper copy, the sheets are sequentially fed from the paper feed tray 21 and sent to the image forming position, that is, the transfer position via the registration rollers 24. In this case, the sheet is placed on the sheet feed tray 21 with the surface on which the image is not formed being aligned downward.

If it is desired to form an image on a blank sheet after erasing the image, the sheet fed from the image erasing paper feed tray 21 passes through the image erasing device 60 and after the image is erased, the transport path is changed. The sheet is switched to the sheet storage unit 45 via the branch conveyance path 88. This sheet storage portion 45
Is supplied via a paper feed roller 45a according to a user's instruction, and an image is formed via a registration roller 24.

As described above, even on a sheet on which an image has been formed, if one surface is in a white state, it is possible to select to form an image on the sheet, and the use range on the user side is large. spread. In addition, since the portion on which the sheet is placed can be sent to the image forming position as it is, the existing path is used as it is,
By arranging the image erasing device 60 in the passage, the image can be selectively erased.

[0152]

As described above, according to the apparatus of the present invention, after erasing a toner image formed on a sheet, the sheet can be efficiently reused for image formation without labor on the user side. can do.

Even if there is an unnecessary portion other than the toner image on the sheet, the sheet can be reproduced into a sheet of a required size, and the reproduced sheet can be efficiently reused.

If one surface on which an image is formed is aligned, image formation can be performed using the sheet, and at the same time, the aligned image formation surface can be erased at a time. . Therefore, while the erasing processing time can be reduced, the sheets can be efficiently reused.

[Brief description of the drawings]

FIG. 1 is a schematic diagram schematically illustrating a sheet conveyance path including an image erasing device according to a first embodiment of the present invention.

FIG. 2 is a control flowchart for explaining image erasure processing control by a control unit in FIG. 1;

FIG. 3 is a cross-sectional view for explaining a basic configuration of an image forming apparatus including the image erasing device of the present invention.

FIG. 4 is a control flowchart for performing an image erasing process in FIG. 3;

FIG. 5 is a schematic diagram schematically illustrating a sheet conveyance path including an image erasing device according to a second embodiment of the present invention.

FIG. 6 is a control flowchart for explaining image erasure processing control by a control unit in FIG. 5;

7 is a schematic diagram schematically illustrating a sheet conveyance path in another mode by the image erasing device illustrated in FIG. 5;

FIG. 8 is a control flowchart for explaining control of an image erasing process by an image erasing apparatus according to a third embodiment of the present invention.

FIG. 9 is a cross-sectional view showing another development in the embodiment of the present invention and showing the entire image forming apparatus provided with the image erasing device.

FIG. 10 shows another development in the embodiment of the present invention, and is a cross-sectional view of the entire image forming apparatus showing another example including the image erasing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image forming part 2 Photoreceptor 3 Charging device 4 Exposure part 5 Developing device 6 Transfer device 7 Cleaning device 8 Laser irradiation device 10 Optical system (scanner) 17 Paper feed tray 18 Paper feed tray 19 Intermediate tray 21 Image erasing tray 22 Transport Path 23 Conveying roller 24 Registration roller 26 Fixing device 45 Image-erased sheet storage unit 60 Image erasing device 61 Processing liquid application nozzle for toner removal 62 Removal roller 69 Transport path (path) 70 Contact sensor 71 First cutting device 72 First 2 cutting device 74 switchback transport path 77 transport means 78 switching member 79 transport path 88 branch transport path

Claims (10)

[Claims] 1. An image which feeds a sheet stored in a sheet feeding tray, sends the sheet to an image forming position to form an image on the sheet, forms an image, and outputs the sheet after the image formation to the outside of the apparatus. In the forming apparatus, an image erasing sheet feeding tray accommodating a sheet on which an image is formed, feeding means for feeding a sheet in the image erasing sheet feeding tray, and a sheet fed by the feeding means. An image erasing device arranged in a passage for feeding a sheet and erasing an image formed on the sheet; a reading sensor for reading an image forming state of the sheet conveyed in the passage; and a sheet sized for conveying the sheet conveyed in the passage. A cutting device that cuts the image into a plurality of pieces, and recognizes an unnecessary portion that cannot be erased by the image erasing device based on the data read by the reading sensor. Control means for reproducing the sheet, a communication path provided for feeding and accommodating the sheet, which has been image-erased by the image erasing device and changed to a predetermined size by the cutting device, into the paper feed tray, and An image forming apparatus provided with an image erasing device, comprising: 2. The paper feed tray according to claim 1, wherein said paper feed tray comprises a plurality of paper feed trays for storing sheets of different sizes and selectively feeding the sheets. An image forming apparatus comprising the image erasing device according to claim 1, wherein the image forming device is sent to a paper tray. 3. The apparatus according to claim 1, wherein the control unit controls the cut portion so that the sheet size is maximized when an unnecessary portion read by the reading sensor is removed by the cutting device. 3. An image forming apparatus comprising the image erasing device according to 2. 4. An image which feeds a sheet stored in a sheet feeding tray, sends the sheet to an image forming position to form an image on the sheet, forms an image, and outputs the sheet after the image formation to the outside of the apparatus. In the forming apparatus, an image erasing sheet feeding tray accommodating a sheet on which an image is formed, feeding means for feeding a sheet in the image erasing sheet feeding tray, and a sheet fed by the feeding means. An image erasing device arranged in a passage for feeding a sheet and erasing an image formed on the sheet; a reading sensor for reading an image forming state of the sheet conveyed in the passage; A switchback transport path for reversing the front and back surfaces of the sheet, and determining whether to reverse the front and back surfaces of the sheet using the switchback transport path based on the data read by the reading sensor. Control means for controlling the image formed on at least one side of the sheet to erase the image via the image erasing device, and transferring the sheet erased by the image erasing device to the sheet feeding tray. An image forming apparatus provided with an image erasing device, comprising: a communication path provided for feeding and accommodating. 5. The control unit according to claim 1, wherein the control unit causes the image erasing device to present both sides of the sheet to an image erasing apparatus via a switchback conveyance path in order to delete an image formed on both sides of the sheet. 5. An image forming apparatus provided with an image erasing device according to claim 4, wherein an image erasing device can be appropriately selected by presenting only a determined surface for erasing the erased image to the image erasing device. 6. An image forming apparatus comprising the image erasing device according to claim 4 or 5, further comprising cutting means for appropriately cutting a sheet conveyed through the passage, wherein the control means reads data read by a reading sensor. Recognize unnecessary parts that cannot be erased by the image erasing device based on
An image forming apparatus provided with an image erasing device, wherein a sheet is reproduced to a predetermined size by removing unnecessary portions using the cutting means. 7. The control means recognizes a punch hole forming position based on data read by a reading sensor, and performs sheet reversal using a switchback conveyance path so that the punch holes are aligned. An image forming apparatus comprising the image erasing device according to claim 4, wherein whether to perform the operation is controlled. 8. An image which feeds a sheet stored in a sheet feeding tray, sends the sheet to an image forming position to form an image on the sheet, forms an image, and outputs the sheet after the image formation to the outside of the apparatus. In the forming apparatus, an image erasing sheet feeding tray accommodating a sheet on which an image is formed, feeding means for feeding a sheet in the image erasing sheet feeding tray, and a sheet fed by the feeding means. An image erasing device that is arranged in a passage communicating with the image forming position to feed out the sheet and erases an image formed on the sheet; a reading sensor that reads an image forming state of the sheet conveyed through the passage; and the image forming position The conveyance path for feeding the sheet passing through the image erasing tray to the image erasing tray in the same posture, and the image erasing sheet feeding with the sheet passing through the image forming position reversed. A switchback transport path for returning to the tray, and selectively passing through the transport path or the switchback transport path to align an image forming surface formed on a sheet based on data read by the reading sensor. Control means for controlling to return to the image erasing paper feed tray and thereafter to perform an image erasing process via the image erasing apparatus, and an image erasing apparatus provided with the image erasing apparatus. apparatus. 9. The image erasing sheet feeding tray includes an intermediate tray for temporarily storing a sheet on which an image has been formed once for forming an image on both sides of the sheet or forming a composite image on the same side. 9. An image forming apparatus comprising the image erasing device according to claim 8, wherein the image forming device is also used. 10. An image which feeds a sheet stored in a sheet feed tray, sends the sheet to an image forming position to form an image on the sheet, forms an image, and outputs the sheet after the image formation to the outside of the apparatus. In the forming apparatus, an image erasing sheet feeding tray accommodating sheets arranged so that the surfaces on which images are formed are aligned in the same direction; and a feeding unit for feeding the sheet in the image erasing sheet feeding tray. An image erasing device that sends out a sheet fed by the feeding means and is disposed in a passage communicating with the image forming position to delete an image formed on the sheet; and a sheet erased by the image erasing device. An image-erased sheet accommodating section for accommodating the image-erased sheet, a branch conveyance path for feeding the sheet, the image of which has been erased by the image erasing apparatus, to the image-erased sheet accommodating section, Control means for enabling the user to appropriately select whether to feed the sheet stored in (a) to the image forming position or to feed the sheet to the image-erased sheet storage unit after passing through the image erasing device. An image erasing device comprising the image erasing device.