JP2016090929A - Sheet processing device and image forming system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet processing device capable of determining whether or not a thermal color extinction recording agent is used; and an image forming system.SOLUTION: A pre-heating image on a sheet conveyed from an image forming apparatus is read by a pre-heating reading part 121. Then, a post-heating image on the sheet is read by a post-heating reading part 122 after the sheet is heated by a heating device 123 to a temperature or higher at which a thermal color extinction ink is decolored. Subsequently, it is determined whether or not a thermal color extinction recording agent is used on the basis of the read pre-heating image and post-heating image, and the determination result is notified to a user by, for example, displaying the result on an operation display part 163.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a sheet processing apparatus and an image forming system.

  Conventionally, a sheet processing apparatus that performs predetermined processing such as binding processing and folding processing on a sheet conveyed from an image forming apparatus is known.

  Patent Document 1 describes a ballpoint pen using a heat-erasable ink that develops color at room temperature (25 ° C.) and becomes colorless at 60 ° C. or higher. The cap part of this ballpoint pen is provided with a friction body. By rubbing the letters written on the paper several times with the friction body, the letters are erased by heating the letters with frictional heat to 60 ° C. or higher. Be able to.

  It is common sense that ink characters written using a ballpoint pen, a sign pen, etc. cannot be erased, unlike a pencil. For this reason, invoices and official documents are often required to be written with a ballpoint pen or a sign pen so as not to be tampered with, for example, erased and rewritten after approval. However, since ink characters written with a ballpoint pen using heat-erasable ink can be erased, fraud such as counterfeiting or falsification of documents using this ballpoint pen is a problem. For example, write the amount of money on the invoice using the above ballpoint pen, get the approval for the invoice, erase the amount on the invoice by decoloring by heating, restate the inflated amount, It is a problem such as billing.

  In order to solve the above-described problem, the invention according to claim 1 is a sheet processing apparatus for performing a predetermined process on a sheet attached to an image forming apparatus and conveyed from the image forming apparatus. A heating unit that heats a part, an image reading unit that reads an image on a sheet, an image before and after heating is read by the image reading unit, and a heating erase is performed based on image information before and after heating read by the image reading unit. And a judging means for judging whether or not a color recording agent is used.

  According to the present invention, it can be determined whether or not a heat-erasable recording agent is used.

1 is a diagram showing a schematic configuration mainly of an image forming apparatus of an image forming system according to an embodiment. 1 is a schematic configuration diagram of a sheet processing apparatus. FIG. 5 is a control block diagram for determining whether to use heat-erasable ink. FIG. 5 is a control flow diagram for determining whether to use heat-erasable ink. The figure which shows an example of the display of an operation display part. The figure which shows the operation display part which expanded and displayed the part in which the heat decoloring ink was used. The figure which shows the other example of a display of an operation display part. FIG. 6 is a control flow diagram for determining whether to use heat-erasable ink so that an image range can be specified. The figure which shows an example of the range setting screen displayed on an operation display part. The figure which shows an example of a sheet | seat heating when using the heating apparatus which can be partially heated. FIG. 10 is a schematic configuration diagram illustrating a sheet processing apparatus according to a first modification. FIG. 9 is a control block diagram for determining whether to use a heat-erasable ink according to Modification 1; FIG. 10 is a schematic configuration diagram illustrating a sheet processing apparatus according to a second modification. FIG. 9 is a control block diagram for determining whether to use heat-erasable ink according to a second modification. FIG. 10 is a schematic configuration diagram illustrating a sheet processing apparatus according to a third modification. FIG. 9 is a control block diagram for determining whether to use heat-erasable ink according to Modification 3. FIG. 4 is a control block diagram for determining whether to use heat-erasable ink in a sheet processing apparatus that determines whether to use heat-erasable ink on both sides of a sheet with a single reading unit. FIG. 10 is a schematic external view showing a sheet processing apparatus and an image forming apparatus according to a fourth modification. FIG. 10 is a schematic configuration diagram illustrating a sheet processing apparatus according to a fourth modification. FIG. 14 is a schematic configuration diagram illustrating another form of a sheet processing apparatus according to a fourth modification. FIG. 10 is a schematic configuration diagram showing still another form of a sheet processing apparatus according to modification example 4; FIG. 10 is a schematic configuration diagram showing still another form of a sheet processing apparatus according to modification example 4; The figure which shows an example of the heating apparatus of a heat roller system. The figure which shows an example of the heating apparatus of a heat belt system. The figure which shows an example of the heating apparatus of an induction heating system. The figure which shows the other example of the heating apparatus of an induction heating system. The figure which shows another example of the heating apparatus heated while conveying a sheet | seat. The figure which shows another example of the heating apparatus heated while conveying a sheet | seat. The figure which shows an example of the heating apparatus which can be partially heated. The figure which shows an example of the heating apparatus which heats a sheet | seat without contact. The figure which shows the other example of the heating apparatus which heats a sheet | seat non-contactingly.

An image forming system according to an embodiment of the present invention will be described with reference to FIG.
FIG. 1 is a diagram illustrating a schematic configuration diagram mainly of an image forming apparatus 1 of the image forming system according to the present embodiment. The image forming system includes an image forming apparatus 1 and a sheet processing apparatus 6 that is communicably connected to the image forming apparatus 1 and mechanically coupled thereto.

  As shown in FIG. 1, the image forming apparatus 1 includes an image forming unit 2 disposed substantially at the center of the apparatus main body 1 </ b> A of the image forming apparatus 1, and a paper feeding unit 3 disposed below the image forming unit 2. Have. In addition, a paper discharge unit 4 disposed above the image forming unit 2 and a scanner 5 disposed above the apparatus main body 1A and serving as an image reading unit that reads a document image are provided.

  On one side of the apparatus main body 1A (left side in FIG. 1), a sheet processing apparatus 6 having at least one of a punching apparatus such as a punch unit, a sorting apparatus such as a sorter, a binding apparatus, and a folding apparatus is installed. Yes.

  A relay conveyance unit as a sheet relay conveyance device is provided in an in-cylinder discharge portion 7 having a discharge space 7a formed on the lateral side of the discharge portion 4 in the apparatus main body 1A and below the scanner 5. 8 is provided. The relay conveyance unit 8 conveys the sheet P from the paper discharge unit 4 to the sheet processing apparatus 6.

  Two paper feed cassettes 9 that can be attached to and detached from the apparatus main body 1A are mounted in the paper feed unit 3, and sheets P of different paper types are accommodated in each of them.

  The sheet P is fed by a sheet feeding roller 11 from a sheet feeding cassette 9 to a conveyance path 10 extending in a substantially vertical (vertical) direction from the sheet feeding unit 3 to the sheet discharging unit 4. The sheet P is conveyed in the conveyance path 10 by the conveyance roller 12, and an image is formed and fixed by the image forming unit 2. Thereafter, the paper is discharged to the relay transport unit 8 by the paper discharge roller 13.

  The image forming unit 2 is provided with a photoconductor 15 as an image carrier that is driven to rotate counterclockwise as indicated by an arrow in the drawing, an optical writing device 16 that forms an electrostatic latent image on the photoconductor 15, and the like. ing. Further, a charging device 17 as a charging device for uniformly charging the photoconductor 15 is disposed around the photoconductor 15 in the counterclockwise direction of the photoconductor 15. There are also provided a developing device 18 for visualizing the electrostatic latent image on the photosensitive member 15 by attaching toner, and a transfer device 19 for transferring the toner image formed by the developing device 18 to the conveyed sheet P. It is installed. Further, a cleaning unit 20 for removing the toner remaining on the photoconductor 15 after transfer and cleaning the photoconductor 15 is also provided.

  Between the transfer device 19 and the paper discharge unit 4, a fixing device 21 is provided as a fixing unit that heats and pressurizes the toner image transferred to the sheet P by the transfer device 19 and fixes the toner image on the sheet P.

  The optical writing device 16 exposes the surface of the photoconductor 15 with a laser beam based on image data from the scanner 5 or image information input from a personal computer or the like, and performs optical writing to perform surface writing on the surface of the photoconductor 15. An electrostatic latent image is formed thereon.

  Sheets P are selectively fed by one of the upper and lower sheet feeding cassettes 9 and then separated one by one by a pair of separation rollers 22, and conveyed in the conveyance path 10 by the conveyance roller 12. Is done.

  Further, the conveyance of the sheet P is temporarily stopped by the registration roller pair 23 provided on the upstream side of the transfer device 19 in the sheet conveyance direction. Thereafter, the toner image is transferred to the nip portion between the transfer device 19 and the photosensitive member 15 by the registration roller pair 23 at a predetermined timing, and the toner image is transferred from the photosensitive member 15 to the sheet P at the nip portion.

  The scanner 5 includes a contact glass 25 on which a document is placed and a white pressure plate 26 that presses the document. In addition, an illumination lamp 27 for irradiating light on the document placed on the contact glass 25, a scanning mirror 28 for reflecting back and reflecting light from the surface of the document, and an optical path folding mirror pair 29a that moves at half the speed of the scanning mirror 28 29b. Furthermore, an imaging lens 30 and a CCD (charge coupled device) 31 as an image sensor are also provided.

  The relay conveyance unit 8 is provided with a paper discharge tray portion 8a on the upper surface thereof, and a roller conveyance portion 8b for conveying a sheet discharged to the sheet processing apparatus 6 therein. Further, the relay conveyance unit 8 includes a first conveyance unit 32 and a second conveyance unit 33. Further, a branching claw 34 is provided as a branching member that switches the path of the sheet P discharged from the paper discharge roller 13 to the first transport unit 32 or the second transport unit 33. The first transport unit 32 transports the sheet P discharged from the paper discharge roller 13 of the paper discharge unit 4 to the paper discharge tray unit 8a. The second transport unit 33 transports the sheet P discharged from the paper discharge roller 13 to the roller transport unit 8b.

  The first transport unit 32 is provided with a paper discharge roller 35 that is a first transport unit discharge roller that discharges the sheet P to the paper discharge tray unit 8a. The roller conveyance unit 8 b that communicates with the second conveyance unit 33 includes a relay conveyance path 36 that communicates with the sheet processing apparatus 6 in the relay conveyance unit 8. In addition, the two transport rollers 37 disposed on the relay transport path 36 and the second transport section discharge unit that is disposed on the most downstream side in the sheet transport direction of the relay transport path 36 and discharges the sheet P to the sheet processing apparatus 6. A paper discharge roller 38 which is a paper roller is also provided.

  In addition, the relay conveyance unit 8 is provided with a relay paper discharge sensor 214 for detecting a jam of a sheet being conveyed on the relay conveyance path 36. The two conveyance rollers 37 and the paper discharge roller 38 are connected to each other via a driving force transmission mechanism such as a pulley and a belt, and are rotationally driven by a single relay conveyance motor 215.

  FIG. 2 is a schematic configuration diagram of the sheet processing apparatus 6 according to the present embodiment. The sheet processing apparatus 6 performs predetermined processing on a sheet conveyed from the image forming apparatus 1 such as a copying machine or a printer.

  The sheet P discharged from the image forming apparatus 1 passes through a conveyance path indicated by a two-dot chain line in the figure, and when requested by the image forming apparatus 1, performs a designated process and then moves outside the apparatus. Discharged. The branching claw 103 is connected to a solenoid (not shown), and the conveyance path can be switched to either the upper tray 110 side or the lifting tray 111 side by rotating the branching claw 103 by the solenoid.

<When discharging the sheet P to the upper tray 110>
The conveyance path is switched to the upper tray 110 side by the branching claw 103. Then, the sheet P is conveyed toward the upper tray 110 by the entrance roller 101, the intermediate conveyance roller 104, and the paper discharge roller 105, which are rotationally driven by a motor and a driving belt (not shown).

<When sorting and discharging sheets P to the lifting tray 111>
The conveyance path is switched to the lifting tray 111 side by the branching claw 103, and the sheet P is conveyed toward the lifting tray 111 by the entrance roller 101, the shift roller 106, and the discharge roller pair.

  The pair of paper discharge rollers is configured to be opened and closed by the upper paper discharge roller 107 coming into contact with and separated from the lower paper discharge roller 113 by a motor and a drive transmission system (not shown), and is being transported in the transport path. The paper discharge roller pair is opened and closed in accordance with the position of the sheet P.

  The sheet processing apparatus 6 measures the position of the sheet P in the conveyance path based on the sheet detection by the entrance sensor 130 and the driving amount of the motor that drives the entrance roller 101 and the like. Based on the measurement result, before the leading edge of the sheet reaches the pair of discharge rollers, one discharge roller 107 is separated from the other discharge roller 113, and the discharge roller pair is opened. In this state, the sheet P being conveyed is shifted to the near side and the far side of the drawing by the shift roller 106. Before the trailing edge of the sheet passes through the shift roller 106, the sheet is sandwiched between one sheet discharge roller 107 and the other sheet discharge roller 113, and the sheet P is discharged onto the lifting tray 111 by the pair of sheet discharge rollers. Thus, the sheets P can be stacked on the lifting tray 111 in a state where the sheets P are sorted on the front side and the back side of the drawing.

  The lifting tray 111 is provided with a rear end pressing mechanism, which is not shown in FIG.

<When discharging the sheet bundle subjected to the end binding process to the lifting tray 111>
The conveyance path is switched to the lifting tray 111 side by the branching claw 103, and the sheet P is conveyed by the entrance roller 101 and the shift roller 106. At this time, one discharge roller 107 is separated from the other discharge roller 113. On the downstream side of the shift roller 106 in the sheet conveyance direction, a tapping roller 201 is provided for tapping the sheet P onto the staple tray 202.

  The hitting roller 201 is connected to a drive transmission system such as a motor and a belt (not shown), and can be lowered while rotating to a position in contact with the staple tray 202 or can be raised from a position in contact with the staple tray 202. A return roller 204 is provided on the side of the staple tray 202 close to the stapler 210. The return roller 204 is connected to a drive system (not shown), and can feed the sheets P temporarily stacked on the staple tray 202 toward the reference fence 205.

  The sheet P received from the image forming apparatus 1 is conveyed by the entrance roller 101 and the shift roller 106, and after the trailing end of the sheet has passed through the shift roller 106, the sheet P is struck down to the staple tray 202 by the tapping roller 201. Then, by rotating each of the hitting roller 201 and the return roller 204, the sheet P is fed toward the reference fence 205, the rear end of the sheet is abutted against the reference fence 205, and the sheet P is conveyed in the conveying direction (length direction). carry out. At the same time, the direction (width direction) perpendicular to the conveyance direction of the sheet P is aligned on the staple tray 202 by the jogger fence 203 swingably installed on the front side and the back side of the drawing. .

  Here, when the sheet P temporarily stacked on the staple tray 202 is long, the leading end of the sheet may come into contact with the lifting tray 111.

  After a plurality of sheets P are stacked and aligned on the staple tray 202, the stapler 210 staples the rear end portion of the sheet bundle to bind the sheets. Thereafter, one discharge roller 107 is moved to the other discharge roller 113 side, the discharge roller pair is closed, the leading end of the sheet bundle is held between the discharge roller pair, and the discharge roller pair is rotated. Then, the sheet bundle is discharged to the lifting tray 111. The position of the sheet bundle to be discharged in the conveyance path is measured based on the detection of the sheet bundle by the paper discharge sensor 131 provided in the vicinity of the paper discharge roller pair and the driving amount of the paper discharge roller pair.

  The stapler 210 is provided so as to be movable to the front side and back side of the drawing, which is the width direction of the sheet bundle, by a drive system such as a motor (not shown), and is configured to be movable to a position suitable for the sheet size and binding position. Has been. When binding the trailing end of the sheet bundle in two places, the stapler 210 is moved in the width direction of the sheet bundle after alignment, and the second staple is performed on the trailing end of the sheet bundle.

  The reference fence 205 can be retracted in the lower left direction in the figure from a conveyance path indicated by a two-dot chain line by a drive transmission system such as a motor and a cam (not shown). When the edge binding process is performed on the sheet bundle, the reference fence 205 is not retracted, and the fence surface with which the sheet rear end of the reference fence 205 is abutted is positioned so as to block the conveyance path substantially vertically. Keep it.

<When a sheet bundle subjected to saddle stitching processing is discharged to the center folding tray 112>
When the saddle stitching process is performed, the sheet bundle is stacked and aligned on the staple tray 202 as in the case of the edge stitching process. Thereafter, the conveying roller 301 is moved in a direction in contact with the staple tray 202 by a driving system such as a motor (not shown), and the sheet bundle is pressed on the roller surface of the conveying roller 301. Then, after retracting the reference fence 205 to a position that does not obstruct the conveyance path, the conveyance roller 301 is rotated to convey the sheet bundle on the staple tray 202 downward by a predetermined amount according to the sheet size. That is, when the center of the sheet bundle conveyance direction (length direction) reaches the staple position of the stapler 210, conveyance of the sheet bundle by the conveyance roller 301 is stopped. Then, the stapler 210 is moved in the width direction of the sheet bundle, and stapling is performed at two positions in the center in the sheet bundle conveyance direction (length direction).

  The stapled sheet bundle is conveyed downward by the conveyance rollers 301 and 302, and the conveyance is stopped when the stapled position of the sheet bundle reaches the position of the folding blade 304. Thereafter, the folding blade 304 is pushed out in the left direction in the drawing by a driving system such as a motor (not shown), and the sheet bundle is pushed into the nip portion of the folding roller pair 303. Then, the sheet bundle is conveyed toward the middle folding tray 112 while being pressed by the folding roller pair 303 and the discharge roller pair 305. As a result, the sheet bundle is folded in half and discharged onto the folded tray 112.

  The processing that the sheet processing apparatus 6 performs on the sheet is not limited to the sorting processing, alignment processing, stapling processing, and half-folding processing described above. For example, it includes any processing for the sheet P such as other types of folding processing such as Z-folding, bookbinding processing using glue, and hole punching processing for forming punch holes in the sheet.

  In addition, the sheet processing apparatus according to the present embodiment performs predetermined processing such as heat processing on the sheet and image reading processing for reading the images before and after heating formed on the sheet, and the sheet is heated and erased as a heat decoloring recording agent. A heating / decoloring ink determination unit 120 that determines whether or not color ink is used is provided.

  The heat decoloring ink determination unit 120 is disposed between the entrance roller 101 and the branch claw 103. The heating decoloring ink determination unit includes a heating device 123, a pre-heating reading unit 121 disposed upstream of the heating device 123 in the sheet conveying direction, and a post heating unit disposed upstream of the heating device 123 in the sheet conveying direction. A reading unit 122. Further, a lamp 161 as a determination result notifying unit for notifying the determination result of the heat decoloring ink determining unit 120 is provided on the upper surface of the casing of the apparatus. Further, it has a speaker as a determination result notifying unit for generating a warning sound and the operation display unit 163 for displaying the determination result when it is determined that the heat-erasable ink is used. In this embodiment, the sheet processing apparatus includes a display unit and a speaker. However, the user may be notified using the operation display unit and the speaker of the image forming apparatus.

FIG. 3 is a control block diagram for determining whether to use the heat decoloring ink.
As shown in FIG. 3, the sheet processing apparatus 6 is provided with a memory 140 that is a nonvolatile storage unit. In this memory 140, the pre-heating image information storage unit 141 storing the pre-heating image data read by the pre-heating reading unit 121 and the post-heating image information storing the post-heating image read by the post-heating reading unit 122 are stored. And a storage unit 142.

  When it is determined that the heat-erasable ink is not used, the pre-heating image data stored in the pre-heating image information storage unit 141 and the post-heating image data stored in the post-heating image information storage unit 142 are: Erased. When it is determined that the heat-erasable ink is used, the image data before heating and the image data after heating are stored as they are. As described above, when it is determined that the heat-erasable ink is used, the image data before heating and the image data after heating are stored in the memory 140 without being erased. These image data can be used as evidence that attempts to act illegally.

  The characters written in the heat-erasable ink disappear when heated, but when it is determined that the heat-erasable ink is used, the pre-heating image data is stored in the memory 140 without being erased. By doing so, an image disappeared by heating can be confirmed. In addition, it may be necessary to rewrite a character that has disappeared by heating with a writing instrument that uses ink other than the heat-erasable ink. In particular, when a long sentence is described using a heat-erasable ink, it is very troublesome to re-describe it with a writing instrument using an ink other than the heat-erasable ink. However, by storing the pre-heating image data in the memory 140 without erasing, the pre-heating image data can be transmitted to the image forming apparatus 1 and printed. Thereby, the trouble of rewriting again with a writing instrument using ink other than the heat decoloring ink does not occur. Further, the image printed from the image forming apparatus 1 is formed with toner and does not lose its color even when heated.

  Further, the sheet processing apparatus 6 includes a control unit 150 that controls the entire apparatus such as heating control of the heating apparatus 123 and sheet conveyance control. The control unit 150 includes a CPU and a ROM that stores a control program for controlling each device. The CPU controls each device of the sheet processing apparatus 6 based on a control program stored in the ROM. The ROM stores a heat-erasable ink determination control program, and the use of the heat-erasable ink can be determined by executing the heat-erasable ink determination control program.

  The control unit 150 includes a determination unit 151 that determines whether or not heat-erasable ink is used. The determination unit 151 compares the pre-heating image read by the pre-heating reading unit 121 with the post-heating image read by the post-heating reading unit 122, and determines whether or not the heat-erasable ink has been used. Based on the result determined by the determination unit 151, the control unit 150 controls the operation display unit 163 as a determination result notification unit to display a result as described later. Further, the lamp 161 as the determination result notification unit is turned on, or a warning sound is generated by the speaker 162.

FIG. 4 is a control flow diagram for determining whether to use the heat decoloring ink.
The user sets a sheet for determining whether to use the heat-erasable ink in the paper feed cassette 9 or the manual feed tray, and operates the operation display unit 163 to set the mode for determining the use of the heat-erasable ink. When the star key is pressed, the control unit 150 conveys the set sheet. The sheet is conveyed to the sheet processing apparatus 6 through the image forming apparatus 1 and the relay conveyance unit 8.

  Further, when the heat decoloring ink use determination mode is set, the heating unit such as the heater of the fixing device 21 of the image forming apparatus 1 is turned off, and the fixing roller of the fixing device is separated from the pressure roller. The sheet for determining whether to use the heat decoloring ink set in the paper feed cassette 9 or the manual feed tray passes through the fixing device 21. However, the heating unit of the fixing device 21 is turned off, and the fixing roller and the pressure roller are separated from each other, so that when the sheet passes through the fixing device 21, the sheet is heated and decolored by the fixing device 21. It is prevented from being heated to temperature.

  When the sheet conveyed to the sheet processing apparatus 6 passes through the pre-heating reading unit 121, the image on the sheet is read by the pre-heating reading unit 121, and the pre-heating image data is stored in the memory 140 before heating image information. Is stored in the unit 141 (S1).

  The sheet that has passed through the pre-heating reading unit 121 is conveyed to the heating device 123 and heated by the heating device 123. The heating device 123 is controlled so that the sheet can be heated at a temperature equal to or higher than the temperature (for example, 60 ° C.) at which the heat-erasable ink is erased. As a result, the image written using the heat-erasable ink on the sheet is erased by the heating of the heating device 123.

  The sheet heated by the heating device 123 is conveyed to the post-heating reading unit 122 and the post-heating image is read by the post-heating reading unit 122. The post-heating image data read by the post-heating reading unit 122 is stored in the post-heating image information storage unit 142 of the memory 140 (S2).

  When the pre-heating reading unit 121 reads the pre-heating image, the control unit 150 performs color separation on the pre-heating image data read by the determination unit 151. As a mode for decomposing, either the RGB mode or the CMYK mode may be used. Next, the color-separated image data of each color is binarized to calculate the number of pixels of black (pixel value 1). When the post-heating reading unit 122 reads the post-heating image, the post-heating image data read by the determination unit 151 is color-separated, and the image data of each color is binarized to calculate the number of black pixels. Then, the determination unit 151 calculates a difference S for each color by subtracting the number of black pixels in the image data after heating from the number of black pixels in the image data before heating for each color (S3). This difference S is the number of pixels changed from black (pixel value 1) to white (pixel value 0), and represents the number of pixels changed before and after heating.

  Next, the determination unit 151 calculates the degree of change R (%) for each color using the difference S and the number of black pixels in the image data before heating (change degree R (%) = (difference S). / Number of black pixels in the image before heating) × 100). The degree of change R is the ratio of pixels that have changed from black (pixel value 1) to white (pixel value 0) before and after heating. It is checked whether or not the calculated degree of change R of each color exceeds a set determination threshold T (S4). In this embodiment, the determination threshold T is 5%.

  The image described with the heat-erasable ink disappears by being heated by the heating device 123. Therefore, when the heat-erasable ink is used, the number of black pixels in the image data after heating is smaller than the number of black pixels in the image data before heating. Therefore, the degree of change R increases and the degree of change R exceeds the determination threshold value T. On the other hand, when the heat-erasable ink is not used, the images are the same before and after heating. Therefore, the number of black pixels in the image data after heating is substantially the same as the number of black pixels in the image data before heating. Therefore, the degree of change R is ≈0 and is equal to or less than the determination threshold T. Therefore, when at least one of the calculated degrees of change R of the colors exceeds the determination threshold T (Yes in S4), the determination unit 151 determines that the heat-erasable ink is being used. On the other hand, when all the calculated change degrees R of the respective colors are equal to or less than the determination threshold T (No in S4), the determination unit 151 determines that the heat-erasable ink is not used.

  Further, the determination threshold T may be set by the user. For example, when there are more than half of the entire image where there is a possibility that the heat-erasable ink is used, such as a report, even if the determination threshold value T is increased, accurate determination can be performed. Also, when the proportion of the entire image, such as an invoice or contract, where there is a possibility of using the heat-erasable ink is small, there is a possibility that the determination cannot be made correctly unless the determination threshold T is set small. is there. By making the determination threshold value T settable by the user, it is possible to set the optimal determination threshold value T according to the document to be determined, and to provide a more convenient device.

  In this embodiment, the image data before and after heating is color-separated and the use of the heat-erasable ink is determined for each color. However, binarization is performed and the number of black pixels is determined without performing color separation. It may be calculated. In this embodiment, the degree of change R (difference S is the ratio of the number of pixels of the image before heating) is used to determine the use of the heat-erasable ink. However, the difference S indicating the number of changed pixels is used. Based on this, use of the heat decoloring ink may be determined. In this embodiment, the number of changed pixels is grasped on the basis of the number of pixels of black (pixel value 1) in the binarized image data, but white (pixel) in the binarized image data. The number of changed pixels may be grasped based on the number of pixels of value 0). In this case, the difference S (number of pixels changed before and after heating) can be calculated by subtracting the number of white pixels before heating from the number of white pixels after heating.

  When the determination unit 151 determines that the heat-erasable ink is not used, the control unit 150 stores pre-heating image data corresponding to the determined sheet stored in each image information storage unit of the memory 140, and heating. Delete the post-image data. On the other hand, when the determination unit 151 determines that the heat-erasable ink is used, the operation display unit 163 is controlled to notify the user that the heat-erasable ink is being used. Further, the lighting of the lamp 161 is controlled or a warning sound is generated by the speaker 162 to notify the user that the heat-erasable ink is being used. Further, the pre-heating image data stored in the pre-heating image information storage unit 141 and the post-heating image data stored in the post-heating image information storage unit 142 are stored in the memory 140 as they are without being erased.

  The sheet processing apparatus can determine whether an image such as a character written on a sheet is written with heat-erasable ink. Therefore, before approving the document, the document is set in the image forming apparatus 1 and it is determined whether or not the heat-erasable ink is used. Then, by approving only the document determined that the heat-erasable ink is not used, it is possible to prevent tampering such as erasing and rewriting characters written in the heat-erasable ink after the approval.

  Whether or not the heat-erasable ink is used is determined by rubbing the written characters and applying frictional heat to the characters, so that the characters written with the heat-erasable ink disappear and the heat-erasable ink is used. Can be determined. However, it is cumbersome and troublesome for the approver to check whether or not the heat-erasable ink has been used by rubbing the written characters on each document. In particular, when approving a large amount of documents, it is a very complicated operation. However, by using the sheet processing apparatus 6, the approver simply sets the document to be approved on the image forming apparatus 1 and presses the start button of the operation display unit 163, and the heat-erasable ink is used for the document to be approved. It is possible to grasp whether or not it has been done. Therefore, it is possible to grasp whether or not the heat-erasable ink is used without taking time and effort.

  When it is determined that the heat-erasable ink is used, the pre-heating image data stored in the pre-heating image information storage unit 141 and the post-heating image data stored in the post-heating image information storage unit 142 are: , It is saved without being erased. As described above, when it is determined that the heat-erasable ink is used, the image data stored in the memory 140 is stored in the memory 140 by storing the image data before heating and the image data after heating in the memory 140. , Can be used as evidence to try fraud. In addition, using the pre-heating image data stored in the memory 140, an image disappeared by heating by the image forming apparatus 1 can be reproduced on a sheet.

FIG. 5 is a diagram illustrating an example of display on the operation display unit 163.
FIG. 5A is a diagram illustrating an example of a display when the heat decoloring ink determination mode is set, and FIG. 5B is a diagram illustrating an example of a display after the heat decoloring ink determination.
For example, when a sheet determined by the user is set in a paper feed cassette and the operation display unit 163 is operated to enter the heating / decoloring ink use determination mode, an image as shown in FIG. 5A is displayed. When the user touches the reading start button 163 a displayed on the operation display unit 163, the heating / decoloring ink determination operation is started, and the sheet set in the image forming apparatus 1 is conveyed and sent to the sheet processing apparatus 6. Then, as described above, the pre-heating image and the post-heating image are read, and the determination unit 151 determines whether or not the heat-erasable ink has been used. When the determination is performed by the determination unit 151 described above, the determination result is displayed on the operation display unit 163 as illustrated in FIG. When the heat-erasable ink is used, “decolored” is displayed, and the read pre-heating image and post-heating image are displayed. Thus, by displaying the pre-heating image and the post-heating image on the operation display unit 163, the difference between the pre-heating image and the post-heating image can be confirmed, and the heating decoloring ink is used in any part of the sheet. You can grasp what was happening. In the example shown in FIG. 5B, it can be confirmed that the heat decoloring ink was used in the description of the amount.

  Further, in the example shown in FIG. 5B, when the decolored portion enlargement button is displayed and the user touches the button, the pre-heating image and the post-heating image on the operation display unit 163 are displayed as shown in FIG. A portion where the heat-erasable ink is used is enlarged and displayed at the display location. For example, a part where the heat-erasable ink is used is a part, and the part where the heat-erasable ink is used can be grasped from the pre-heating image and the entire display of the image after heating shown in FIG. May be difficult. At this time, the user touches the decolored portion enlargement button 163b to enlarge and display the portion where the heat decolored ink is used, as shown in FIG. It can be easily grasped.

  5B is displayed on the operation display unit 163, and the lamp 161 is turned on as shown in FIG. 1 or a warning sound is emitted from the speaker 162. You may alert | report that the color ink was used. By informing through the lamp 161 or the speaker 162, it is possible to confirm that the heat-erasable ink has been used without confirming the display on the operation display unit 163.

  When the heat-erasable ink is used, the read pre-heating image data and post-heating image data are stored in the memory 140 without being erased. Then, by operating the operation display unit 163, the pre-heating image data and post-heating image data stored in the memory 140 can be displayed and the contents can be confirmed. However, a document for determining whether or not heat-erasable ink is used is a confidential document or the like, which may cause a problem when viewed by a third party. Therefore, as shown in FIG. 7, the storage setting image is displayed on the display screen when the heating / decoloring ink use determination mode is set, and the user can set whether to store the read image. Good.

  When the document to be judged is a confidential document or the like and is a document that is problematic when viewed by a third party, the user touches the “OFF” button of the save setting image 163c. As a result, even when the determination unit 151 determines that the heat-erasable ink has been used, the pre-heating image data and post-heating image data stored in each image information storage unit of the memory 140 after the determination are deleted. Thereby, it is possible to determine whether or not the heat-erasable ink is used while maintaining confidentiality of the document.

Further, a range for determining the use of the heat-erasable ink may be designated.
FIG. 8 is a control flow diagram for determining whether to use the heat decoloring ink so that the image range can be specified.

  First, the user operates the operation display unit 163 to execute the image range designation mode. When the image range designation mode is executed, the control unit 150 displays on the operation display unit 163 that the sheet for which the range is designated is set in the image forming apparatus 1 and the reading start button is pressed. When the user sets a sheet whose range is specified in the image forming apparatus 1 and presses a reading start button, the sheet is conveyed and the image on the sheet is read by the pre-heating reading unit. The read image is displayed on the operation display unit 163 or the screen of the personal computer. Further, an image on a sheet whose range is specified by the scanner 5 of the image forming apparatus 1 may be read.

FIG. 9 is an example of a range setting screen displayed on the operation display unit 163.
As shown in FIG. 9, an image for designating the read range is displayed and a designated range setting screen 163d is displayed. A designation frame 163f is also displayed on the read range designation image. The user designates a range by inputting a numerical value into “□” on the designated range setting screen 163d. “Upper” on the designated range setting screen corresponds to the position of the upper end of the designated frame 163f, and “Lower” on the designated range setting screen corresponds to the position of the lower end of the designated frame 163f. Further, “right” on the designated range setting screen corresponds to the right end position of the designated frame 163f, and “left” on the designated range setting screen corresponds to the left end position of the designated frame 163f. For example, if a numerical value larger than “98” displayed in “□” of “Up” on the designated range setting screen is input, the position of the upper end of the designated frame 163f moves upward, and the vertical direction of the designated frame 163f The range expands. In this way, while confirming the image to be specified for the range and the specification frame 163f, a numerical value is input to the specified range setting screen “□” to specify the image range to be determined (S1). When the designation of the image range to be determined is finished, the user touches the designation end button 163e. When the designation end button 163e is pressed, the control unit 150 associates the range designation image with the designation range (input up / down / left / right values) and stores them in the memory 140. Thus, the range setting operation can be omitted when the use of the heat-erasable ink is determined next time for the same document. In FIG. 9, the position is specified by the number of pixels (pixels), but the position may be specified by a length (mm) from the paper reference end. Also, the user may be able to select whether to set the pixel or the length.

  When the image range to be determined is designated in this way, the pre-heating image and the post-heating image are read in the same manner as described above (S12, S13). At this time, the range to be read is the designated image range. As a result, the image data to be read can be reduced. Next, the determination unit 151 calculates a difference S for each color (S14). In this case, the image data before and after heating is color-separated or binarized to calculate the number of black pixels. However, since the image data is small, the calculation load is small and the difference can be made quickly. S can be calculated.

  Next, based on the calculated difference S, the degree of change R is calculated, and it is checked whether the degree of change R exceeds the determination threshold T (S15). Also in this case, since the image range to be determined is designated, it is possible to increase the sensitivity of detecting the heat-use ink. As shown in FIG. 9, the designated image range is a range that is less than 10% of the entire image data. In addition, in the image shown in FIG. 9, there is a possibility that the heat-erasable ink may be used in a column for entering the amount of money next to “¥”, and the entire image data is larger than the designated image range. The share is small. As a result, depending on the contents of the document, even if heat-erasable ink is used, the degree of change R is several percent.

  On the other hand, by designating the image range to be determined, it is possible to increase the proportion of the portion where the heat-erasable ink may be used. As a result, when the heat-erasable ink is used, the degree of change R increases. Thereby, the sensitivity of detection of the heat-use ink can be increased, and an accurate determination can be performed.

  In addition, as shown in FIG. 10, when the heating device 123 is arranged in a direction perpendicular to the paper transport direction and can heat the paper partially, the plurality of heating parts 123a are arranged in the image range to be determined. Only the heating section 123a at the corresponding location may be turned on. Thereby, compared with the case where the whole sheet | seat is heated, reduction of power consumption can be aimed at.

  In this embodiment, the sheet processing apparatus includes the operation display unit 163. However, the operation display unit of the image forming apparatus may be controlled to display the above-described display on the operation display unit of the image forming apparatus. Alternatively, application software may be installed on a personal computer and the above-described display may be performed on the personal computer.

  Further, a sheet not using the heat decoloring ink is discharged to the lifting tray 111, and a sheet using the heat decoloring ink is subjected to, for example, saddle stitching processing and discharged to the middle folding tray 112, The discharge destination may be divided. In this way, by making the discharge destination different between the sheet that does not use the heat-erasable ink and the sheet that is used, after the continuous determination, the sheet that uses the heat-erasable ink itself is used. It is not necessary to sort the sheets that have not been used. Thereby, a highly convenient apparatus can be provided. In addition, since the sheet using the heat decoloring ink is subjected to the saddle stitching process, the sheet using the heat decoloring ink can be easily identified.

  Further, a sheet determined to be using heat-erasable ink may be discharged to the upper tray 110. Further, the user may be able to set the discharge destination. Specifically, the user operates the operation display unit to perform the saddle stitching process on the sheet in which the heat-erasable ink is used, and sets whether to discharge the sheet to the half-folding tray 112 or the upper tray 110. .

  Further, by changing the discharge position to the lifting tray 111 in the sheet width direction between the sheet using the heat decoloring ink and the sheet not using the heat decoloring ink, the sheet using the heat decoloring ink and the sheet not using it. May be distinguished. In this case, the shift roller 106 shifts the sheet using the heat-erasable ink and discharges it to a position different from the sheet using the heat-erasable ink in the width direction. Even if it discharges in this way, it is not necessary for the user to perform the sorting process after the continuous determination.

  Further, when the sheet processing apparatus includes a punching device, it is discharged after performing punching processing on a sheet in which the heat-erasable ink is used, and whether or not the ink is heat-erasable ink can be sorted depending on the presence or absence of the punching. It may be.

  Next, a modified example of the sheet processing apparatus 6 will be described.

[Modification 1]
FIG. 11 is a schematic configuration diagram illustrating the sheet processing apparatus according to the first modification, and FIG. 12 is a control block diagram for determining whether to use the heat decoloring ink of the sheet processing apparatus according to the first modification.
In the first modification, one reading unit 124 reads images before and after heating.
A sheet for determining whether to use the heat-erasable ink set in a manual feed tray or a paper feed cassette of the image forming apparatus is conveyed to the sheet processing apparatus and passed through the heating apparatus 123. At this time, the heating device 123 is OFF, so that the sheet is not heated by the heating device 123. When the sheet that has passed through the heating device 123 passes through the reading unit 124, the image before heating is read by the reading unit 124. The pre-heating image read by the reading unit 124 is stored in the pre-heating image information storage unit 141 of the memory 140. A rear end detection sensor 125 is disposed between the reading unit 124 and the branch claw 103. When the rear end detection sensor 125 detects the rear end of the sheet, the sheet is switched back and the sheet is heated. Reverse transport toward 123. When the sheet passes through the heating device 123, the heating device 123 heats the sheet to a temperature equal to or higher than the temperature at which the heat-erasable ink is decolored. After the sheet passes through the heating device 123, the sheet is switched back again and conveyed toward the reading unit 124. When the sheet passes through the reading unit 124, the image after heating is read by the reading unit 124, and the read image after heating is stored in the image information storage unit 142 after heating in the memory 140. The sheet that has passed through the reading unit 124 is discharged to the lift tray 111 or the upper tray 110. As described above, when the reading unit 124 reads the pre-heating image and the post-heating image, the determination unit 151 determines whether to use the heat-erasable ink in the same manner as described above.

  You may perform the timing which reads the image before a heating, when the sheet | seat is reversely conveyed toward the heating apparatus 123. FIG.

  In the first modification, the image before and after heating can be read by one reading unit 124, and the number of parts can be reduced as compared with the case where the reading unit before heating and the reading unit after heating are provided, and the cost of the apparatus is reduced. You can go down.

  In addition, when the pre-heating image and the post-heating image are read by separate reading units, when comparing the pre-heating image and the post-heating image, the comparison accuracy is reduced due to the influence of individual reading units. For this reason, in order to increase the comparison accuracy, it is necessary to determine a correction value based on individual differences and to correct the calculated difference S with the correction value. On the other hand, in the first modification, since the image before and after heating is read by one reading unit 13, there is no influence due to the individual difference of the reading unit. Therefore, correction due to individual differences in the reading unit is unnecessary, and accurate determination is possible.

  Further, the heating device 123 may be disposed downstream of the reading unit 124 in the sheet conveyance direction. In this case, first, the image before heating is read by the reading unit 124 and heated by the heating device 123. After passing through the heating device 123, the sheet is switched back and conveyed back to the reading unit 124 again, and the reading unit 124 reads the image after heating. When the image is read after heating, it is switched back and discharged to the lifting tray 111 or the upper tray 110.

[Modification 2]
FIG. 13 is a schematic configuration diagram illustrating a sheet processing apparatus according to the second modification. FIG. 14 is a control block diagram for determining whether to use the heat-erasable ink in the sheet processing apparatus according to the second modification.
In the second modification, a front surface reading unit 124a that reads an image on the front surface of the sheet and a back surface reading unit 124b that reads an image on the back surface of the sheet are provided. It is possible.

  First, a sheet for determining use of heat-erasable ink set in the image forming apparatus is conveyed, the front surface heating unit 124a reads the front surface heating image, and the back surface reading unit 124b reads the back surface heating image. read. The front surface heating image read by the front surface reading unit 124 a is stored in the pre-surface heating image information storage unit 141 a of the memory 140. The pre-back surface heating image read by the back surface reading unit 124b is stored in the pre-back surface heating image information storage unit 141b of the memory 140.

  Next, the sheet is conveyed to the heating device 123, and is heated by the heating device 123 to a temperature equal to or higher than the temperature at which the heat-erasable ink on both sides of the sheet is erased. When the trailing edge of the sheet exits the heating device 123, the sheet is switched back to reversely convey the sheet, and the image after the front surface heating is read by the front surface reading unit 124a, and the back surface heating is performed by the back surface reading unit 124b. After image is read. The front surface heated image read by the front surface reading unit 124 a is stored in the post-surface heating image information storage unit 142 a of the memory 140. The backside heated image read by the backside reading unit 142b is stored in the backside heated image information storage unit 142b of the memory 140. Thereafter, the sheet is switched back and discharged to the lifting tray 111 or the upper tray 110.

  When the image after the front surface heating and the image after the rear surface heating are read, the image before the front surface heating stored in the image information storage unit 141a before the front surface heating and the image information storage after the front surface heating are stored. The surface heated image stored in the unit 142a is read out. Then, the front surface determination unit 151a of the control unit 150 performs image processing similar to that described above, calculates the difference S, obtains the degree of change R, and determines whether or not the degree of change R exceeds the determination threshold value T. A check is made to determine whether heat decoloring ink is used on the front side of the sheet.

  Further, the back-side pre-heating image stored in the pre-back-side heating image information storage unit 141b and the back-side heating image stored in the back-side heating image information storage unit 142b are read. Then, the back side determination unit 151b of the control unit 150 performs the same image processing as described above, calculates the difference S, obtains the degree of change R, and checks whether the degree of change R exceeds the determination threshold value T. Then, it is determined whether or not the heat-erasable ink is used on the back surface of the sheet.

  If it is determined that the heat-erasable ink is used on either the front surface or the back surface of the sheet, the determination result notification unit such as the operation display unit 163, the lamp 161, the speaker 162, etc. Informing that heat-decoloring ink is used on either the front surface or the back surface.

  Thereby, it is possible to determine whether or not the heat decoloring ink is used for both the front surface and the back surface of the sheet.

[Modification 3]
FIG. 15 is a schematic configuration diagram illustrating a sheet processing apparatus according to a third modification. FIG. 16 is a control block diagram for determining the use of heat-erasable ink in the sheet processing apparatus according to the third modification.
In the third modified example, the image before and after the heating of the front surface and the image before and after the heating of the back surface can be read by one-pass conveyance in which the sheet passes only once.
As illustrated in FIG. 15, in the third modification, the front surface heating pre-reading unit 121 a that reads the pre-heating image on the front surface of the sheet and the heating of the back surface of the sheet are arranged upstream of the heating device 123 in the sheet conveyance direction. A backside pre-heating reading unit 121b that reads the previous image is arranged. Further, on the downstream side of the heating device 123 in the sheet conveyance direction, a front surface heating reading unit 122a that reads a heated image on the front surface of the sheet, and a back surface heating reading unit that reads a heated image on the back side of the sheet. 122b.

  When the sheet for determining whether to use the heat-erasable ink set in the image forming apparatus is conveyed to the sheet processing apparatus, the image before the front surface heating is read by the reading unit 121a before the front surface heating, and the reading unit before the rear surface heating is performed. The pre-back surface heating image is read by 121b. The front surface heating image read by the front surface heating reading unit 121 a is stored in the pre-surface heating image information storage unit 141 a of the memory 140. On the other hand, the pre-backside heating image read by the pre-backside heating reading unit 121b is stored in the pre-backside heating image information storage unit 141b of the memory 140.

  Next, the sheet is heated by the heating device 123 to a temperature at which the front and back surfaces are decolored by the heated decolored ink. Next, the image after the front surface heating is read by the reading unit 122a after the front surface heating, and the image after the rear surface heating is read by the reading unit 122b after the rear surface heating. The image after the surface heating read by the reading unit 122a after the surface heating is stored in the image information storage unit 142a after the surface heating in the memory 140. On the other hand, the post-backside heating image read by the post-backside heating reading unit 122 b is stored in the post-backside heating image information storage unit 142 b of the memory 140. Then, the sheet is discharged to the elevating tray 111 or the upper tray 110.

  After reading the image after the front surface heating and the image after the rear surface heating, the front surface determination unit 151a is used using the image before the front surface heating and the image after the front surface heating in the same manner as described above. Then, it is determined whether or not the heat decoloring ink is used on the front surface of the sheet. Further, using the pre-back surface heating image and the back surface post-heating image, the back surface determination unit 151b determines whether or not the heat decoloring ink is used on the back surface of the sheet. Then, if it is determined that the heat-erasable ink is used on either the front surface or the back surface of the sheet, the determination result notifying unit heats or erases either the front surface or the back surface of the sheet. Notify that colored ink is being used.

  In the third modification, it is possible to determine whether or not the heat-erasable ink has been used for both the front surface and the back surface of the sheet in one-pass conveyance that requires only one pass of the sheet. Compared to, it is possible to make a quick determination.

Further, by providing a reverse conveyance path that allows the sheet processing apparatus to reverse the sheet and convey the sheet again to the reading unit, it is possible to read the images before and after heating on both sides of the sheet with one reading unit.
FIG. 17 is a control block diagram for determining the use of heat-erasable ink in a sheet processing apparatus that determines the use of heat-erasable ink on both sides of a sheet with a single reading unit.
In this case, first, the sheet is conveyed to the reading unit 124, the image before the front surface heating is read by the reading unit 124, and the read front surface heating image information is stored in the memory 140 before the front surface heating image information. Stored in the unit 141a. Next, after the sheet is conveyed to the reverse conveyance path, the sheet is reversed, and then conveyed again to the reading unit 124. The reading unit 124 reads the image before the back surface heating, and the image information storage unit before the back surface heating of the memory 140 is read. 141b. Next, the sheet is conveyed to the heating device 123, and the heating device 123 heats both sides of the sheet at a temperature equal to or higher than the temperature at which the decoloring ink is decolored, and then conveys the sheet again to the reverse conveyance path. After reversing the sheet in the reverse conveyance path, the sheet is conveyed to the reading unit 124 three times. Then, the image after the surface heating is read by the reading unit 124, and the read image after the surface heating is stored in the image information storage unit 142 a after the surface heating of the memory 140. Next, the sheet is conveyed three times to the reverse conveyance path and is conveyed again to the reading unit 124. Then, the image after back surface heating is read by the reading unit 124, and the read back surface heated image is stored in the back surface heated image information storage unit 142 b of the memory 140.
Thereby, the image before and behind the heating of both surfaces of a sheet | seat can be read with one reading part. Thereafter, as described above, based on the read images before and after heating on both sides of the sheet, each of the determination units 151a and 151b determines whether or not the heat-erasable ink is used on the front surface and the back surface of the sheet. . When it is determined that the heat-erasable ink is used on either the front surface or the back surface, the determination result notification unit such as the lamp 161, the speaker 162, and the operation display unit 163 is controlled to notify the user. .

[Modification 4]
FIG. 18 is a schematic external view showing the sheet processing apparatus according to the fourth modification and the image forming apparatus 1. FIG. 19 is a schematic configuration diagram showing the sheet processing apparatus according to the fourth modification.
The sheet processing apparatus according to the fourth modification is set in the in-body discharge unit 7 of the image forming apparatus.
Similarly to the sheet processing apparatus set on the side surface of the image forming apparatus, the sheet processing apparatus according to the fourth modification also includes an entrance roller 101 and an entrance sensor 130 at a receiving port for receiving a sheet from the image forming apparatus. Also in the fourth modification, the shift roller 106 is provided so that the sheets can be stacked on the paper discharge tray 114 in a state where the sheets are sorted on the front side and the back side of the drawing. Yes. Specifically, one of the paper discharge rollers 107 is positioned at an open position away from the other paper discharge roller 113 in the solid line in the figure. In this state, the sheet P being conveyed is shifted to the near side and the far side of the drawing by the shift roller 106. Before the trailing edge of the sheet passes through the shift roller 106, one discharge roller 107 is moved to a closed position in contact with the other discharge roller 113 shown by the dotted line in the drawing, and the sheet P is discharged to the discharge tray 114 by the discharge roller pair. To discharge. Thus, the sheets P can be stacked on the paper discharge tray 114 in a state where the sheets P are sorted on the front side and the back side of the drawing.

  In addition, the sheet processing apparatus according to the fourth modification has an end binding processing function. In the case of applying to a sheet, the sheet P is conveyed by the entrance roller 101 and the shift roller 106 with one discharge roller 107 positioned at the open position of the solid line in the drawing. The sheet P conveyed by the tapping roller 201 provided downstream of the shift roller 106 in the sheet conveying direction is struck down to the staple tray 202. Then, by rotating each of the hitting roller 201 and the return roller 204, the sheet P is fed toward the reference fence 205, the rear end of the sheet is abutted against the reference fence 205, and the sheet P is conveyed in the conveying direction (length direction). carry out. At the same time, the direction (width direction) perpendicular to the conveyance direction of the sheet P is aligned on the staple tray 202 by the jogger fence 203 swingably installed on the front side and the back side of the drawing. .

  After a plurality of sheets P are stacked and aligned on the staple tray 202, the stapler 210 staples the rear end portion of the sheet bundle to bind the sheets. Thereafter, one discharge roller 107 is moved to the closed position indicated by the dotted line in the figure, the leading end of the sheet bundle is held between the one discharge roller 107 and the other discharge roller 113, and the discharge roller pair is rotated. Then, the sheet bundle is discharged to the discharge tray 114. The position of the sheet bundle to be discharged in the conveyance path is measured based on the detection of the sheet bundle by the paper discharge sensor 131 provided in the vicinity of the paper discharge roller pair and the driving amount of the paper discharge roller pair.

  In the fourth modification, a heat-erasable ink determination unit 120 is disposed between the entrance roller 101 and the shift roller 106. The heating / decoloring ink determination unit 120 has the same configuration as the heating / decoloring ink determination unit 120 mounted on the sheet processing apparatus shown in FIG. Specifically, a pre-heating reading unit 121, a heating device 123, and a post-heating reading unit 122 are provided. In the modified example 4, as described above, the pre-heating image is read by the pre-heating reading unit 121 on the sheet for determining whether to use the heat-erasable ink conveyed from the image forming apparatus. Thereafter, the heated decoloring ink is heated to a temperature at which the decolored ink is decolored, and then the heated image is read by the post-heating reading unit 122.

  As shown in FIG. 20, the heating / decoloring ink determination unit 120 mounted on the sheet processing apparatus according to Modification 4 may include one reading unit 124. In this case, similarly to the first modification, after the sheet is passed through the reading unit 124 and the pre-heating image is read, the sheet is passed through the heating device 123 and the sheet is heated to a temperature at which the decolorizing ink is decolored. Heat. Thereafter, when the trailing edge of the sheet is detected by the trailing edge detection sensor 125, the sheet is switched back, the sheet is conveyed backward to the reading unit 124, and the image after heating is read by the reading unit 124. After reading the image after heating, the sheet is switched back again and the sheet is conveyed toward the paper discharge tray 114.

  In addition, as shown in FIG. 21, a front surface reading unit 124a and a back surface reading unit 124b are provided, and the sheet is conveyed in the same manner as in the second modification example. Use determination may be performed. Furthermore, as shown in FIG. 22, a front surface heating pre-reading unit 121a, a back surface pre-heating reading unit 121b, a front surface heating post-reading unit 122a, and a back surface heating post-heating reading unit 122b are provided. The images before and after heating on both sides of the sheet may be read to determine whether to use the heat-erasable ink on both sides of the sheet.

  In addition, the heat decoloring ink determination unit 120 may be disposed in the relay conveyance unit 8 shown in FIG. The heat-erasable ink determination unit 120 performs predetermined processing on the sheet, such as heat-treating the sheet by the heating device 123. Therefore, the relay conveyance unit 8 including the heat-erasable ink determination unit 120 has a function as a sheet processing apparatus.

Next, the heating device 123 will be described.
As the heating device 123, a heat roller system configured by a pair of rollers as shown in FIG.
A heating device 123 shown in FIG. 23 includes a heating roller 123a, a pressure roller 123b that forms a nip between the heating roller, and a thermal heater 123c as a heating unit. In FIG. 23, a heating control unit (not shown) for controlling the thermal heater is provided, and the thermal heater 123c is controlled based on detection information from the thermistor 123d that detects the surface temperature of the heating roller 123a. An advantage of the heat roller system is that it has a paper transport function, and the configuration of the apparatus can be simplified.

Further, as a method for heating the sheet P while being conveyed, there is also a heat belt method.
FIG. 24 is a diagram illustrating an example of a heat belt type heating device 123. This system has a heating belt 223c stretched between a pressure roller 223b, a stretching roller 223a, and a belt heating roller 223d. A thermal heater 223e for heating the belt heating roller 223d is provided in the belt heating roller 223d. Further, a thermistor 223f that detects the temperature of the heating belt 223c is provided. The heating belt 223c rotates in the direction of arrow A in the drawing to transmit the heat of the belt heating roller to the sheet P conveyed to the nip that contacts the pressure roller 223b.
The advantage of this heat belt method is that a long nip is ensured and heat can be applied to the sheet even if it is operated at high speed. Further, by selecting a member having a small heat capacity for the heating belt and the belt heating roller, it is possible to shorten the waiting time until the set temperature.

  In the above description, the thermal roller is used to heat the heating roller 123a and the heating belt 223c by the heat of the thermal heater. The roller and belt may be heated by induction heating.

FIG. 25 is a diagram illustrating an example of an induction heating type heating device 123.
25 includes an induction heating unit 330 serving as a magnetic flux generation unit, a heating sleeve 322 serving as a heat generating member, a heating roller 321, a pressure roller 323, and the like.

Here, the heating sleeve 322 as a heat generating member is formed by sequentially forming an elastic layer 322b and a release layer 322c on a base material 322a made of a metal material having a thickness of 30 to 50 μm, and has an outer diameter of 40 mm. It has become. As a material for forming the base material 322a of the heating sleeve 322, a magnetic metal material such as iron, cobalt, nickel, or an alloy thereof can be used.
The elastic layer 322b of the heating sleeve 322 is made of an elastic material such as silicone rubber and has a thickness of 150 μm. Thereby, the heat capacity is not so large, and the sheet can be heated satisfactorily without heating unevenness.

  The release layer 322c of the heating sleeve 322 is obtained by coating a fluorine compound such as PFA in a tube shape, and the thickness thereof is 50 μm. The heating roller 321 is formed by forming a heat-resistant elastic layer 321b made of silicone foam on a cylindrical cored bar 321a made of a metal material such as stainless steel, and has an outer diameter of about 40 mm. The elastic layer 321b of the heating roller 321 has a thickness of 9 mm and an Asker hardness on the shaft of 30 to 50 degrees. The heating roller 321 is in contact with the inner peripheral surface of the heating sleeve 322 and holds the thin heating sleeve 322 in a roller shape.

  The pressure roller 323 is formed by sequentially forming a heat-resistant elastic layer 323b such as silicone rubber and a release layer (not shown) on a cored bar 323a made of a highly thermally conductive metal material such as aluminum or copper. And the outer diameter is 40 mm. The elastic layer 323b is formed to have a thickness of 2 mm. The release layer is coated with a PFA tube and is formed to have a thickness of 50 μm. The pressure roller 323 is in pressure contact with the heating roller 321 via the heating sleeve 322, and a nip portion is formed in the pressure contact portion. Then, the sheet P is conveyed to the nip portion.

  The induction heating unit 330 as a magnetic flux generation unit includes an exciting coil 331, a core unit 332, a demagnetizing coil unit 333, and the like. The excitation coil 331 extends in the width direction (in the direction perpendicular to the paper in FIG. 25) by winding a litz wire bundled with thin wires on a coil guide disposed so as to cover a part of the outer periphery of the heating sleeve 322. It is what. The demagnetizing coil unit 333 is disposed symmetrically with respect to the positional relationship corresponding to the sheet width direction, and is disposed so as to overlap the exciting coil 331. The core portion 332 is made of a ferromagnetic material such as ferrite (having a relative permeability of about 2500), and a center core 332b and a side core 332a are provided to form an efficient magnetic flux toward the heating sleeve 322. . The core portion 332 is installed so as to face the exciting coil 331 extending in the width direction.

The heating device 123 configured as described above operates as follows.
When the pressure roller 323 is driven to rotate counterclockwise in FIG. 25 by the drive motor, the heating sleeve 322 also rotates clockwise. At this time, the heating roller 321 holding the heating sleeve 322 is not actively driven to rotate. Then, the heating sleeve 322 as the heating member and the heating member is heated by the magnetic flux generated from the induction heating unit 330 at a position facing the induction heating unit 330.

Specifically, by supplying a high-frequency alternating current of 10 kHz to 1 MHz (preferably 20 kHz to 800 kHz) from the power supply unit to the exciting coil 331, magnetic field lines are alternately alternated in the vicinity of the heating sleeve 322 facing the exciting coil 331. It is formed to switch to By forming the alternating magnetic field in this manner, an eddy current is generated in the base material 322a (heat generation layer) of the heating sleeve 322, and the base material 322a is inductively heated by generating Joule heat due to its electric resistance.
Thus, the heating sleeve 322 is heated by induction heating of its base material 322a.

  The surface of the heating sleeve 322 heated by the induction heating unit 330 reaches the nip portion with the pressure roller 323. Then, the conveyed sheet P is heated to a temperature (60 ° C.) or higher at which the heat-erasable ink disappears. Specifically, the sheet P from which the pre-heating image has been read is fed between the heating sleeve 322 and the pressure roller 323 while being guided by the guide plate 324 (the movement in the transport direction indicated by the arrow Y1). The sheet P is fed from the nip portion while being heated by the heat received from the heating sleeve 322 and being separated from the heating sleeve 322 by the heating separation plate 325 and the pressure separation plate 326. The surface of the heating sleeve 322 that has passed through the nip portion then reaches the position facing the induction heating unit 330 again.

FIG. 26 is a diagram illustrating another example of the induction heating type heating device 123.
FIG. 26 shows an example of a heat belt system.
The induction heating unit 305 is installed so that the inner peripheral portion faces the belt heating roller. The induction heating unit 305 generates a magnetic flux by energizing a current having an arbitrary frequency characteristic from a control board (not shown), and generates an eddy current in the belt heating roller and the heating belt. In FIG. 26, a thermistor 306 is provided at the outlet in order to prevent overheating by the induction heating unit 305. In addition, an encoder 308 for confirming that the belt heating roller 304 is rotating is also provided.

  Heating by the induction heating method shown in FIGS. 25 and 26 is excellent in energy efficiency, and it is possible to shorten the waiting time until the set temperature. Another feature is that temperature unevenness in the main scanning direction due to the heating means is eliminated.

FIG. 27 is a diagram illustrating another example of the heating device 123 that heats a sheet while conveying the sheet.
The heating device shown in FIG. 27 includes a pressure roller 611, a nip forming member 612, a heating belt 613, a metal pipe 614, and the like. A heater 615, a reinforcing stay 616, and the like are provided. The pressure roller 611 is made of a metal core and silicone rubber, and the nip forming member 612 is made of a fluoro rubber or the like wound with a PTFE sheet or the like. The heating belt 613 is formed by forming a surface layer made of silicone rubber and PFA on the surface of a SUS or Ni base material. The metal pipe 614 is obtained by applying a fluorine-based sliding coating to the outer peripheral surface in contact with the heating belt 613 made of a SUS or Ni base material.

  As the heater 615 generates heat, the metal pipe 614 is heated. Thereby, the temperature of the heating belt 613 in contact with the temperature rises. When the sheet P is conveyed to the nip formed by the heating belt 613, the nip forming member 612, and the pressure roller 611 that has reached the temperature at which the heat decoloring ink disappears, the temperature at which the heat decoloring ink disappears from the sheet P Until heated. The heating belt 613 whose temperature has been lowered by the heating operation is again heated by the heater.

FIG. 28 is a diagram illustrating still another example of the heating device 123 that heats a sheet while conveying the sheet.
As shown in FIG. 28, the heating device 123 includes a heating sleeve 621 formed of a rotating endless belt, and a pressure roller 631 that contacts the outer peripheral surface of the heating sleeve 621. Further, a contact member 626 that is disposed on the inner peripheral side of the heating sleeve 621 and forms a nip portion by contacting the pressure roller via the heating sleeve 621 is provided. Furthermore, a planar heating element 622 is provided on the inner peripheral side of the heating sleeve 621 so as to be in contact with or close to the heating sleeve 621 and heat the heating sleeve 621 directly or indirectly. Further, a heating element support member 623 is provided on the inner peripheral side of the heating sleeve 621 so as to sandwich the planar heating element 622 between the heating sleeve 621 and supports the planar heating element 622 at a predetermined position. FIG. 27 shows a configuration in which the planar heating element 622 abuts on the inner peripheral surface of the heating sleeve 621 and heats directly.

  The sheet conveyed to the nip where the heating sleeve 621 is in contact with the pressure roller 631 by the contact member 626 is heated to a temperature at which the heat-erasable ink disappears by the heating sleeve 621 heated by the planar heating element 622. .

  The heating device 123 shown in FIGS. 27 and 28 can reduce the heat capacity as compared with the heat roller system, and can shorten the waiting time until the set temperature. Further, by making the pressure roller a pad made of an elastic member, the heat capacity can be further reduced, and the waiting time until the set temperature can be shortened. Further, the sheet heating element and the elastic pad that contacts the sheet heating element constitute a heating device. The sheet is conveyed to the nip portion between the sheet heating element and the elastic pad, and the sheet is heated and decolored. The ink may be heated to a temperature at which the ink is decolored. With such a configuration, the heat capacity of the heating device can be further reduced, and the waiting time until the set temperature can be shortened.

As shown in FIG. 29, a plurality of thermal heaters 403 may be arranged in the direction of the rotation axis of the heating roller 401, and the heating area may be divided in the direction of the rotation axis to be heated.
In FIG. 29, a heating roller 401, a pressure roller 402 that forms a nip with the heating roller 401, and a thermal heater 403 are configured, and a plurality of thermal heaters 403 are installed facing the heating roller 401. This thermal heater can independently heat the paper heating roller. By using this independent thermal heater, as described with reference to FIG. 16, it is possible to heat only the image range for determining the use of the heat-erasable ink, thereby reducing the power consumption and the image information. Loss risk can be reduced. Although the heat roller method is described in FIG. 24, the same configuration is possible even with the heat belt method.

Although the heating apparatus shown in FIGS. 23 to 29 is for heating the sheet while being conveyed, the sheet may be heated without contacting the sheet.
FIG. 30 is an example of a heating device that heats a sheet in a non-contact manner.
The heating device in FIG. 30 heats the sheet by applying hot air to the sheet, and includes a blower 501 and a heat source 502. By applying the air heated by the heat source 502 to the sheet P by the blower 501, the sheet is heated to a temperature at which the heat-erasable ink is decolored. Since this method applies heat to the paper surface from above, it is possible to always apply the same amount of heat to the paper surface. Further, since heat is applied to the image in a non-contact manner, the image is not lost.

FIG. 31 is another example of a heating device that heats a sheet in a non-contact manner.
In FIG. 31, the sheet P is heated by the radiant heat of the heat source 502, and includes a heat source 502 and a reflector 503 that surrounds the heat source 502. When the heat generated from the heat source 502 is applied directly or after being reflected by the reflecting plate and hitting the sheet P, the sheet P is heated to a temperature at which the heat-erasable ink is erased. As an advantage of this method, the sheet can be heated up to a temperature at which the heat-erasable ink can be erased in a short time. Further, since heat is applied to the image in a non-contact manner, the image is not lost.

  Further, as the heat source 502, a xenon flash lamp can be used in addition to a nichrome wire or the like. The sheet P is heated by the flash radiation energy from the xenon flash lamp to a temperature at which the heat-erasable ink is erased. By using the xenon flash lamp, the time for the sheet to rise to the temperature at which the heat-erasable ink is erased is 0 [s], and there is no possibility of paper burning.

  Table 1 below is a table for determining the superiority or inferiority of each heating method.

  The “heat roller” in Table 1 is the heating device of the heat roller system shown in FIG. 23, and the “heat belt” is the heating device of the heat belt system shown in FIG. In addition, “IH” is the heating device of the induction heating method shown in FIGS. 25 to 26, and “digital” is the heating device shown in FIG. Further, “warm air” is the heating device shown in FIG. 30, “radiant” is the heating device shown in FIG. 31, and “flash” is the heating device shown in FIG. The heat source is a xenon flash lamp.

  “Temperature unevenness” is defined as “◯” when the sheet P can be heated without temperature unevenness, “Δ” when the temperature unevenness slightly occurs, and “X” when the temperature unevenness is remarkable. “Partial heating” was defined as “◯” when the sheet could be partially heated, “Δ” when the sheet could be partially heated, and “x” when the sheet could not be partially heated. In addition, regarding the sheet conveyance function, “○” indicates that the sheet can be conveyed, and “X” indicates that the sheet cannot be conveyed. The “rise time” is the time required from the OFF state until the heat-erasable ink can be erased. “◎” indicates that the ink rises in a very short time, “○” indicates that it rises in a short time, and “rise”. The standard time is "△".

  “Whether heating on both sides simultaneously” indicates whether it is possible to heat both the front and back sides of the sheet at a temperature above the temperature at which the heat-erasable ink is erased. “◯”, “△” for realization, and “X” for difficult realization. Also, “difficulty in image loss” means that among images formed on a sheet, an image formed with toner is melted by the heat of the heating device. When coming into contact with the sheet, it may adhere to such a molten toner heating member and cause image defects. Therefore, the evaluation results of “heat roller”, “heat belt”, and “IH” that heat while contacting the sheet are “Δ”. The “digital” capable of partial heating has an evaluation result of “◯” because there is no possibility of image loss when it is not heated. On the other hand, “warm air”, “radiant”, and “flash” that heat the sheet in a non-contact manner do not cause image defects, and therefore the evaluation result is “◎”.

  “Temperature control” is an evaluation of whether or not the amount of heat applied to the sheet (sheet temperature) can be controlled. “○” indicates that the temperature can be controlled, and “X” indicates that the temperature cannot be controlled. . By using a heating device capable of controlling the temperature, discoloration of the colored material due to excessive heating of the sheet can be suppressed.

  In addition, the image described with the heat-erasable ink disappears when heated by the heating device 123. When the heat-erasable ink is cooled to a predetermined temperature (−10 ° C.) or less, the decolored ink is colored again. For this reason, the apparatus 1 may be provided with a cooling means for cooling the sheet so that the ink decolored by heating is colored again.

What has been described above is an example, and the present invention has a specific effect for each of the following aspects.
In the sheet processing apparatus 6 that performs predetermined processing on a sheet that is attached to the image forming apparatus and conveyed from the image forming apparatus, a heating unit such as a heating apparatus 123 that heats at least a part of the sheet, An image reading unit that reads the image of the image, and the image reading unit reads the image before and after heating, and determines whether or not the heat-erasable recording agent is used based on the image information before and after heating read by the image reading unit And a determination unit such as a determination unit 151.
According to the first aspect, an image such as a character formed using a heat-erasable recording agent such as a heat-erasable ink is erased by heating with a heating unit. Therefore, it is possible to determine whether or not the heat-erasable recording agent has been used by reading the image before heating and the image after heating with the image reading means and comparing the images before and after heating. More specifically, when the heat-erasable recording agent is not used, there is no difference between the read images before and after heating. However, when a heat-erasable recording agent is used, the image formed by the heat-erasable recording agent disappears, so that a difference occurs between the read images before and after heating. Accordingly, the image reading unit reads the image before heating and the image after heating, compares the images before and after heating, and determines whether the images before and after heating are different, thereby determining whether the images before and after heating are different. It can be determined whether an agent is being used. As a result, before the document is approved, the device is used to determine whether or not the heat-erasable recording agent is used, thereby approving the document using the heat-erasable recording agent. Can be prevented, and fraud such as falsification of a document can be prevented in advance.
In addition, a function for performing a predetermined process on a sheet conveyed from the image forming apparatus is added to a function for determining whether or not a heat recording agent is used, thereby providing a highly convenient sheet processing apparatus. it can.

(Aspect 2)
In (Aspect 1), the image forming apparatus is set on a side surface or in a cylinder.
According to this, the sheet conveyed from the image forming apparatus can be received from the side surface or the cylinder of the image forming apparatus.

(Aspect 3)
In (Aspect 1) or (Aspect 2), the image reading unit is positioned upstream of the heating unit such as the heating device 123 in the sheet conveyance direction, and includes a pre-heating reading unit 121 that reads an image before heating, and a heating unit. And a post-heating reading unit 122 that reads an image after heating, which is located downstream in the sheet conveying direction.
According to this, it is possible to read an image before heating and an image after heating on one surface of the sheet by one-pass conveyance in which the sheet passes only once.

(Aspect 4)
In (Aspect 1) or (Aspect 2), after the sheet is conveyed in the order of the image reading unit such as the reading unit 124 of the image reading unit such as the reading unit 124 and the heating unit such as the heating device 123, the image reading unit again. Transport the sheet to
According to this, as described in the first modification, first, since the sheet is conveyed to an image reading unit such as the reading unit 124, the image before heating can be read at that time. Next, since the sheet is conveyed to a heating unit as the heating device 123, the sheet can be heated to a temperature at which the heat-erasable recording agent such as heat-erasable ink is erased. Next, since the sheet is conveyed again to the image reading unit, the image after heating can be read at that time. Accordingly, the image before and after heating can be read by one reading unit, and the number of parts can be reduced and the apparatus can be made cheaper than in the case where the image reading unit includes a plurality of reading units. it can. In addition, compared with a case where an image before heating and an image after heating are read by a plurality of reading units, there is no influence due to individual differences in the reading units. Therefore, it is possible to accurately detect the difference between the image before heating and the image after heating, and it is possible to determine the use of the heat-erasable recording agent with high accuracy.

(Aspect 5)
(Aspect 1) to (Aspect 4) In any one of (Aspect 4), the image reading unit reads images before and after heating on both sides of the sheet, and the determination unit is configured to read the sheet information based on the image information before and after heating on both sides of the sheet. It is determined whether a heat-erasable recording agent is used on both sides.
According to this, as described in Modifications 2 to 3, it is possible to determine whether or not the heat decoloring ink is used on both sides of the sheet. As the method for reading the image before and after heating on both sides of the sheet by the image reading unit, as described in the second modification, the image reading unit reads the image on the front side of the sheet. And a back side reading unit that reads an image on the back side of the sheet, and sequentially conveys the sheet to each reading unit and the heating unit, and then conveys the sheet again to each reading unit, thereby reading the images on both sides of the sheet before and after heating. be able to.
In addition, as described in the third modification, the image reading unit reads the image on the front surface of the sheet before heating, the front surface heating reading unit, and the back surface heating before reading the image on the back surface of the sheet before heating. It is also possible to heat both sides of the sheet by including a reading unit, a reading unit after heating the front side of the sheet that reads the image of the heated sheet front surface, and a reading unit after the heating of the back side that reads the image of the back side of the heated sheet. The front and back images can be read.
Further, as described in the embodiment, if the image reading unit is configured to have a reversing path that reverses the sheet that has passed through the image reading unit of the image reading unit and conveys the sheet again to the image reading unit, It is also possible to read images before and after heating on both sides of the sheet with only one reading unit.

(Aspect 6)
In any one of (Aspect 1) to (Aspect 5), a sheet that is determined to be using a heat-erasable recording agent such as a heat-erasable ink by a determination unit such as the determination unit 151, and a heat-erasable recording agent The sheet is discharged separately from the sheet determined not to be used.
According to this, as described in the embodiment, after determining whether or not a heat-erasable recording agent such as a heat-erasable ink is continuously used for a plurality of sheets, the user can It is not necessary to sort the discharged multiple sheets into a sheet using a heat-erasable recording agent and a sheet not in use. Thereby, a highly convenient apparatus can be provided.

(Aspect 7)
In (Aspect 6), the discharge destination of the sheet that is determined to be using a heat-erasable recording agent such as heated color ink by a determination unit such as the determination unit 151, and that the heat-erasable recording agent is not used. The determined sheet discharge destinations are different from each other.
According to this, a sheet determined to be using a heat-erasable recording agent such as a heat-erasable ink and a sheet determined to be not using a heat-erasable recording agent are distinguished and discharged. Can do.

(Aspect 8)
In any one of (Aspect 1) to (Aspect 7), notification means (in this embodiment, the lamp 161, the speaker 162, and the operation display unit 163) that notifies the user of the determination result determined by the determination unit such as the determination unit 151 is provided. Prepared.
According to this, as described in the embodiment, it is possible to make the user aware that a heat-erasable recording agent such as a heat-erasable ink has been used.

(Aspect 9)
In (Aspect 8), the notification unit includes a display unit such as an operation display unit 163 that displays the determination result by the determination unit such as the determination unit 151 and / or the location where the heat-decoloring recording agent is used.
According to this, as described with reference to FIG. 5, it is possible to inform the user of the determination result and / or the location where the heat-erasable recording agent is used.

(Aspect 10)
In (Aspect 8) or (Aspect 9), the notification means includes sound generation means such as a speaker 162 that emits a sound when the determination means such as the determination unit 151 determines that the heat-erasable recording agent is used.
According to this, it is possible to make the user aware that there is a sheet using a heat-erasable recording agent such as heat-erasable ink without the user checking the apparatus.

(Aspect 11)
In any one of (Aspect 1) to (Aspect 10), a display unit such as an operation display unit 163 that displays image information before and after heating read by the image reading unit is provided.
According to this, as described with reference to FIG. 5, the difference between the images before and after heating is confirmed from the image before heating displayed on the display means such as the operation display unit 163 and the image after heating. Can do. Thereby, the user can grasp from the image before and after the heating displayed on the display means which part of the image the heating decoloring recording agent such as the heat decoloring ink is used.

(Aspect 12)
In (Aspect 1) to (Aspect 11), the determination unit such as the determination unit 151 grasps the number of pixels whose pixel value has changed between before and after heating based on image information before and after heating, and the pixel value When the number of pixels having changed is equal to or greater than the threshold value, it is determined that the heat-erasable recording material is used.
According to this, as described in the embodiment, since the heat-erasable recording agent such as the heat-erasable ink is decolored, the pixel value of the pixel corresponding to the heat-erasable recording agent changes before and after heating. Therefore, if the number of pixels in which the pixel value has changed is equal to or greater than the threshold value, it can be determined that the heat-erasable recording material is being used.

(Aspect 13)
In (Aspect 12), setting means such as an operation display unit 163 for setting a threshold value by a user is provided.
According to this, the user can set an optimum threshold according to the document to be determined, and it is possible to make a highly accurate determination.

(Aspect 14)
In (Aspect 1) to (Aspect 13), the determination means such as the determination unit 151 performs color separation on each of the image information before and after heating, and determines whether or not a heat-erasable recording agent is used for each color. Do.
According to this, it is possible to accurately determine the use of a heat decoloring agent such as a heat decoloring ink of various colors.

(Aspect 15)
In any one of (Aspect 1) to (Aspect 14), determination means such as the determination unit 151 determines whether or not a heat-erasable recording material is used for a predetermined range of the sheet.
According to this, as described in the embodiment, it is possible to reduce the calculation load for the image of the entire sheet as compared with the case of determining, and quickly determine whether or not the heat-erasable recording material is used. be able to.
Further, by narrowing the determination range, it is possible to increase the ratio of the portion where the heat-erasable ink may be used. As a result, when the heat-erasable ink is used, the ratio of the number of pixels that changes before and after the heating increases, and the sensitivity of detecting the heat-use ink can be increased. Thereby, a highly accurate determination can be performed.

(Aspect 16)
In (Aspect 15), the determination unit such as the determination unit 151 includes a determination range specifying unit such as an operation display unit 163 for specifying a range for determining whether or not the heat-erasable recording material is used. .
According to this, the user can specify a range in which a heat-erasable recording agent such as a heat-erasable ink on the sheet may be used, and a highly accurate determination can be made for a wide variety of documents. .

(Aspect 17)
(Aspect 1) to (Aspect 16) In any one of (Aspect 16), image information before heating of a sheet determined to be using a heat-erasable recording agent such as heat-erasable ink by a determination unit such as a determination unit 151 is stored. Image information storage means such as a pre-heating image information storage unit 141 is provided.
According to this, as described in the embodiment, the heat-erasable recording agent such as the heat-erasable ink disappears by the heating of the heating device 123. However, an image that has disappeared can be confirmed by storing the image information before heating in an image information storage unit such as the image information storage unit 141 before heating. In addition, using the image information before heating stored in the image information storage unit, an image disappeared by heating by the image forming apparatus 1 can be reproduced on a sheet.

(Aspect 18)
In an image forming system including an image forming apparatus 1 that forms an image on a sheet and a sheet processing apparatus 6 that performs predetermined processing on a sheet conveyed from the image forming apparatus, the sheet processing apparatus is configured as ( The sheet processing apparatus according to any one of 1) to (Aspect 17) was used.
According to this, in addition to the function that can perform predetermined processing such as edge binding processing on the sheet on which an image is formed by the image forming apparatus, the function to perform the use of heat-erasable recording agent such as heat-erasable ink is added. Therefore, it is possible to provide a convenient image forming system.

(Aspect 19)
In (Aspect 18), the image forming apparatus includes a fixing unit such as a fixing device 21 that heats an unfixed image formed on the sheet and fixes the unfixed image on the sheet, and is heated and decolored by a determination unit such as the determination unit 151. When determining whether or not a recording agent is used, the sheet for determining whether or not a heat-erasable recording agent is used is not heated above the temperature at which the heat-erasable recording agent is erased by the fixing unit. In addition, the sheet to be determined is conveyed in the image forming apparatus.
According to this, before the pre-heating image is read by the image reading means provided in the sheet processing apparatus, the heat-erased recording agent such as the heat-erasable ink is erased by the heat of the fixing means. It is possible to prevent heating up to the temperature to be performed.

1: Image forming apparatus 6: Sheet processing apparatus 7: In-body discharge unit 8: Relay conveyance unit 9: Paper feed cassette 21: Fixing apparatus 106: Shift roller 110: Upper tray 111: Lifting tray 112: Middle folding tray 120: Heating Decolored ink determination unit 121: pre-heating reading unit 121a: front surface heating pre-reading unit 121b: back surface pre-heating reading unit 122: post-heating reading unit 122a: front surface heating post-reading unit 122b: back surface heating post-reading Unit 123: Heating device 124: Reading unit 124a: Front surface reading unit 124b: Back surface reading unit 125: Rear end detection sensor 140: Memory 141: Image information storage unit before heating 141a: Image information storage before front surface heating Unit 141b: Image information storage unit 142 before heating back image information storage unit 142a after heating image information storage unit 142a after heating surface information storage unit 142b: Image information storage unit 1 after heating back surface 50: Control unit 151: Determination unit 151a: Front surface determination unit 151b: Back surface determination unit 161: Lamp 162: Speaker 163: Operation display unit

JP 2006-123324 A

Claims (19)

In a sheet processing apparatus for performing a predetermined process on a sheet attached to an image forming apparatus and conveyed from the image forming apparatus,
Heating means for heating at least a part of the sheet;
Image reading means for reading an image on the sheet;
A determination unit that reads an image before and after heating by the image reading unit and determines whether or not a heat-erasable recording agent is used based on image information before and after the heating read by the image reading unit; A sheet processing apparatus. The sheet processing apparatus according to claim 1,
A sheet processing apparatus, wherein the sheet processing apparatus is set on a side surface or a cylinder of the image forming apparatus. In the sheet processing apparatus according to claim 1 or 2,
The image reading unit is positioned upstream of the heating unit in the sheet conveying direction, reads a pre-heating image reading unit, and is positioned downstream of the heating unit in the sheet conveying direction, and the image after heating And a post-heating reading unit. In the sheet processing apparatus according to claim 1 or 2,
A sheet processing apparatus, wherein a sheet is conveyed to the image reading unit again after the sheet is conveyed in the order of the image reading unit of the image reading unit and the heating unit. The sheet processing apparatus according to any one of claims 1 to 4, wherein the image reading unit reads images before and after heating on both sides of the sheet,
The determination unit determines whether or not a heat-erasable recording agent is used on both sides of the sheet based on image information before and after heating both sides of the sheet read by the image reading unit. . The sheet processing apparatus according to any one of claims 1 to 5,
A sheet processing apparatus that distinguishes and discharges a sheet determined by the determination means that a heat-erasable recording agent is used and a sheet determined not to be used by a heat-erasable recording agent . The sheet processing apparatus according to claim 6,
The discharge destination of the sheet determined that the heat-erasable recording agent is used by the determination unit and the discharge destination of the sheet determined that the heat-erasable recording agent are not used are different from each other. A sheet processing apparatus. The sheet processing apparatus according to any one of claims 1 to 7,
A sheet processing apparatus comprising: a notification unit that notifies a user of the determination result determined by the determination unit. The sheet processing apparatus according to claim 8, wherein
The sheet processing apparatus, wherein the notification unit includes a display unit that displays a determination result by the determination unit and / or a location where the heat-decoloring recording agent is used. In the sheet processing apparatus according to claim 8 or 9,
The sheet processing apparatus according to claim 1, wherein the notification unit includes a sound generation unit that emits a sound when the determination unit determines that the heat-erasable recording agent is used. The sheet processing apparatus according to any one of claims 1 to 10,
A sheet processing apparatus, comprising: display means for displaying image information before and after heating read by the image reading means. The sheet processing apparatus according to any one of claims 1 to 11,
The determination means grasps the number of pixels whose pixel value has changed before and after heating based on image information before and after heating, and when the number of pixels whose pixel value has changed is equal to or greater than a threshold value, the heating decoloring recording A sheet processing apparatus that determines that an agent is being used. The sheet processing apparatus according to claim 12, wherein
A sheet processing apparatus comprising setting means for a user to set the threshold value. The sheet processing apparatus according to any one of claims 1 to 13,
The determination unit performs color separation on each of the image information before and after heating, and determines whether or not a heat-erasable recording agent is used for each color. The sheet processing apparatus according to any one of claims 1 to 14,
The sheet processing apparatus, wherein the determination unit determines whether or not a heat-erasable recording material is used for a predetermined range of the sheet. The sheet processing apparatus according to claim 15, wherein
A sheet processing apparatus, comprising: a determination range specifying unit that allows a user to specify a range in which the determination unit determines whether or not a heat-erasable recording material is used. The sheet processing apparatus according to any one of claims 1 to 16,
A sheet processing apparatus comprising image information storage means for storing image information before heating of a sheet determined to be using the heat-erasable recording agent by the determination means. An image forming apparatus for forming an image on a sheet;
In an image forming system provided with a sheet processing apparatus that performs predetermined processing on a sheet conveyed from the image forming apparatus,
An image forming system using the sheet processing apparatus according to claim 1 as the sheet processing apparatus. The image forming system according to claim 18.
The image forming apparatus includes a fixing unit that heats an unfixed image formed on a sheet and fixes the image on the sheet,
When determining whether or not the heat-erasable recording agent is used by the determination unit, a sheet for determining whether or not the heat-erasable recording agent is used is the sheet that determines whether the heat-erasable recording agent is used or not. The image forming system is conveyed in the image forming apparatus so as not to be heated more than a color temperature.

Images