JP2016090517A - Thermal color extinction recording agent use determination device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily determine whether or not a thermal color extinction recording agent is used.SOLUTION: A sheet set in a sheet feed tray 2 is conveyed and a pre-heating image is read by a pre-heating reading part 11. Then, the sheet is conveyed to a heating device 20 and heated by the heating device 20 to a temperature or higher at which a thermal color extinction ink is decolored. Then, the sheet is conveyed to a post-heating reading part 12 and the pre-heating image is read by the pre-heating reading part 11. 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 when the thermal color extinction recording agent is determined to be used, notification to a user is performed by lighting a lamp 15 or giving a warning beep with a speaker 16.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a heating / decoloring recording agent use determination apparatus that determines whether or not a heating / decoloring recording agent that is decolored by heating is used.

  2. Description of the Related Art Conventionally, writing tools such as a ballpoint pen using a heat-erasable ink that is a heat-erasable recording agent that shifts from a colored state to a decolored state by heating are known.

  For example, 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 heated by frictional heat to 60 ° C. or more to erase the letters. 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 of claim 1 is a heating unit that heats at least a part of a sheet, an image reading unit that reads an image on a sheet before and after heating by the heating unit, and the image reading unit. And a determination unit for determining whether or not a heat-erasable recording material is used based on the image information before and after heating read in step (2).

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

1 is a schematic configuration diagram of a heat-decoloring recording agent use determination device of the present embodiment. 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 schematic block diagram of the heat-decoloring recording agent use determination apparatus of the modification 1. FIG. The schematic block diagram of the heat-decoloring recording agent use determination apparatus of the modification 2. FIG. 11 is a control block diagram for determining whether to use heat-erasable ink in Modification 2. The schematic block diagram of the heat-decoloring recording agent use determination apparatus of the modification 3. The schematic block diagram of the heat-decoloring recording agent use determination apparatus of the modification 4. Heat erasing recording provided with a first paper discharge tray that discharges sheets that do not use heat-erasable ink and a second paper output tray that discharges sheets that use heat-erasable ink The schematic block diagram of an agent use determination apparatus. 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. 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. The figure which shows an example of the heat-erasable recording agent use determination apparatus which can detect whether the heat-erasable ink was used about both the front surface and the back surface of the sheet | seat at once. FIG. 3 is a control block diagram for determining the use of a heat-erasable ink in the heat-erasable recording agent use determination device. The figure which shows the other example of the heating-erasing recording agent use determination apparatus which can detect whether the heating-erasing ink was used about both the front surface and the back surface of the sheet | seat at once. FIG. 3 is a control block diagram for determining the use of a heat-erasable ink in the heat-erasable recording agent use determination device. The figure which shows another example of the heating-erasing recording agent use determination apparatus which can detect whether the heating-erasing ink was used about both the front surface and the back surface of the sheet | seat at once. FIG. 3 is a control block diagram for determining the use of a heat-erasable ink in the heat-erasable recording agent use determination device.

FIG. 1 is a schematic configuration diagram of a heat-erasable recording agent use determination apparatus 1 according to the present embodiment.
As shown in FIG. 1, a heat-erasable recording agent use determination apparatus 1 according to the present embodiment includes a paper feed tray 2 for setting a sheet for checking whether or not heat-erasable ink as a heat-erasable recording agent is used. A sheet discharge tray 3 for discharging the sheet after the determination and a heating device 20 for heating the sheet are provided. In addition, a pre-heating reading unit 11 that reads an image written on a sheet before heating is provided between the paper feeding tray 2 and the heating device 20, and between the heating device 20 and the paper discharge tray 3. Is provided with a post-heating reading unit 12 that reads an image written on the heated sheet. In addition, on the upper surface of the casing of the apparatus, a lamp 15 serving as a notification unit and an operation display unit 50 serving as a display unit and serving as a notification unit are provided. The apparatus is also provided with a speaker 16 which is a sound generation means.

FIG. 2 is a control block diagram for determining whether to use the heat decoloring ink.
As shown in FIG. 2, the heat-erased recording agent use determination device is provided with a memory 5 which is a nonvolatile storage means. In this memory 5, the pre-heating image information storage unit 5 a that stores the pre-heating image data read by the pre-heating reading unit 11 and the post-heating image information that stores the post-heating image read by the post-heating reading unit 12. And a storage unit 5b.

  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 5a and the post-heating image data stored in the post-heating image information storage unit 5b are: Erased. On the other hand, 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 5 without being erased. These image data can be used as evidence that attempts to act illegally.

  In addition, characters written in the heat-erasable ink disappear when heated, but when it is determined that the heat-erasable ink is used, the image data before heating is stored in the memory 5 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 image data before heating in the memory 5 without erasing, the image data before heating can be transmitted to a printer or the like for printing. Thereby, the trouble of rewriting again with a writing instrument using ink other than the heat decoloring ink does not occur. Further, the image formed by the printer is not erased by heating.

  The heating / decoloring recording agent use determination apparatus has a control unit 6 that controls the entire apparatus such as heating control of the heating apparatus 20 and sheet conveyance control. The control unit 6 includes a determination unit 6a that compares the image after heating with the image before heating and determines whether or not the heat-erasable ink has been used. Based on the result determined by the determination unit 6a, the control unit 6 controls the operation display unit 50 as a determination result notification unit to display a result as described later. In addition, the lamp 15 as the determination result notification unit is turned on, or a warning sound is generated by the speaker 16 which is a sound generation unit.

FIG. 3 is a control flow diagram for determining whether to use the heat decoloring ink.
When the user sets a sheet P to be used to determine whether to use the heat-erasable ink in the sheet feeding tray 2 and presses the start button, the control unit 6 rotates the sheet feeding roller 4 to rotate the sheet P on the sheet feeding tray. Is conveyed toward the reading unit 11 before heating. When the sheet passes through the pre-heating reading unit 11, the image on the sheet is read by the pre-heating reading unit 11, and the pre-heating image data is stored in the pre-heating image information storage unit 5a of the memory 5 (S1). .

  The sheet P that has passed through the pre-heating reading unit 11 is conveyed to the heating device 20 and heated by the heating device 20. The heating device 20 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 on the sheet P using the heat decoloring ink is decolored by the heating of the heating device 20.

  The sheet P heated by the heating device 20 is conveyed toward the pre-heating reading unit 11, and an image on the sheet is read by the post-heating reading unit 12 when the sheet passes the post-heating reading unit 12. The post-heating image data read by the post-heating reading unit 12 is stored in the post-heating image information storage unit 5b of the memory 5 (S2).

  When the pre-heating reading unit 11 reads the pre-heating image, the control unit 6 performs color separation on the pre-heating image data read by the determination unit 6a. 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 12 reads the post-heating image, the post-heating image data read by the determination unit 6a is color-separated, and the image data of each color is binarized to calculate the number of black pixels. Then, the determination unit 6a calculates the 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. 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 6a 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 20. 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 6a 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 6a 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 6a determines that the heat-erasable ink is not used, the control unit 6 pre-heat image data corresponding to the determined sheet stored in each image information storage unit of the memory 5, and the heating Delete the post-image data. On the other hand, when the determination unit 6a determines that the heat-erasable ink is being used, the operation display unit 50 is controlled to notify the user that the heat-erasable ink is being used. Further, the lighting of the lamp 15 is controlled or a warning sound is generated by the speaker 16 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 5a and the post-heating image data stored in the post-heating image information storage unit 5b are stored in the memory 5 as they are without being erased.

  In this way, the sheet P for which it is determined whether or not the heat-erasable ink is used is discharged to the paper discharge tray 3 by the paper discharge roller 10.

  In the present embodiment, it is possible to determine whether or not an image such as characters written on the sheet is written with heat-erasable ink. The approver sets the document in the apparatus 1 before approving the document, and determines whether the heat-erasable ink has been 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 apparatus 1, the approver sets the document to be approved in the apparatus 1, and simply presses the start button of the apparatus 1, and whether or not the heat decoloring ink is used for the document to be approved. Can be grasped. 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 5a and the post-heating image data stored in the post-heating image information storage unit 5b 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 5 is stored in the memory 5 by storing the image data before heating and the image data after heating in the memory 5. , Can be used as evidence to try fraud. Further, by using the pre-heating image data stored in the memory 5, an image disappeared by heating by the image forming apparatus can be reproduced on a sheet.

[Modification 1]
FIG. 4 is a schematic configuration diagram of the heat-decoloring recording agent use determination apparatus 1a according to the first modification.
In the heat-erased recording agent use determination apparatus 1a according to the first modification, the sheet conveyance path is linear. Thus, by making the sheet conveyance path a simple straight line, the sheet can be conveyed stably, and the occurrence of problems such as jams can be suppressed.

[Modification 2]
FIG. 5 is a schematic configuration diagram of the heat-decoloring recording agent use determination device 1b according to the second modification.
This modification 2 heating / decoloring recording agent use determination apparatus 1b is provided with a loop-shaped loop conveyance path 7, and reads a pre-heating image and a post-heating image by one reading unit 13. In addition, the heating / decoloring recording agent usage determination device 1b of Modification 2 is provided with a switching claw 14 that selectively transports the sheet P to either the loop transport path 7 or the paper discharge tray 3. The heating device 20 is provided in the loop conveyance path 7.

FIG. 6 is a control block diagram of the heat-decoloring ink use determination in the second modification.
The sheet P that is set on the sheet feeding tray 2 and used for determining whether to use the heat-erasable ink is conveyed to the image reading unit 13 by the conveying roller pair 8, and the image reading unit 13 reads the image before heating described on the sheet P. The read pre-heating image is stored in the pre-heating image information storage unit 5a of the memory 5, as shown in FIG. At this time, the switching claw 14 is located at the position of the dotted line in FIG. 5, and the sheet P that has passed through the image reading unit 13 is conveyed to the loop conveyance path 7. The sheet P sent to the loop conveyance path 7 is conveyed to the heating device 20 without being guided by the conveyance guide 7a. Then, in the process of passing through the heating device 20, the heating device 20 is heated at a temperature (60 ° C.) or more at which the heat-erasable ink is decolored. The sheet P heated by the heating device 20 is conveyed toward the conveyance roller pair 8 while being guided by the conveyance guide plate 7 b in order to read the image after heating by the image reading unit 13.

  Since the rotation of the pair of transport rollers 8 is stopped after the trailing edge of the sheet set on the paper feed tray 2 is removed, the leading edge of the heated sheet that has been transported through the loop transport path 7 is transported. It hits roller pair 8. Then, the conveyance of the sheet is temporarily stopped at the timing when the leading edge of the sheet hits the conveyance roller pair 8. Further, the switching claw 14 is swung from the position indicated by the dotted line in FIG. 5 to the position indicated by the solid line in the drawing at a predetermined timing after the leading end of the sheet is directed to the loop conveyance path 7. The reason why the leading edge of the heated sheet abuts against the conveying roller pair 8 is temporarily stopped is that the leading edge of the heated sheet passes through the reading unit 13 and the reading unit 13 reads the heated image on the sheet. This is to match the timing to start the operation.

  When the heated sheet is temporarily stopped, the conveying roller pair is rotationally driven again to convey the heated sheet to the reading unit 13, and the reading unit 13 reads an image after heating. The read after-heating image is stored in the after-heating image information storage unit 5b of the memory 5, as shown in FIG. The heated sheet from which the image after heating is read by the image reading unit 13 is conveyed to the paper discharge tray 3.

  When the image before heating and the image after heating are read by the reading unit 13, the determination unit 6a determines whether or not the heat-erasable ink is used in the same manner as described above. When the heat-erasable ink is used, the operation display unit 50 is controlled to notify the user that the heat-erasable ink is being used. Further, the lighting of the lamp 15 is controlled or a warning sound is generated by the speaker 16 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 5a and the post-heating image data stored in the post-heating image information storage unit 5b are stored in the memory 5 as they are without being erased.

  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 decreases 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 Modification 2, 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.

[Modification 3]
FIG. 7 is a schematic configuration diagram of a heat-decoloring recording agent use determination device 1c according to Modification 3.
In the third modification, switchback conveyance is performed, and the image before and after heating is read by one reading unit 13. In the third modification, a trailing edge detection sensor 9 that detects the trailing edge of the sheet is provided between the heating device 20 and the paper discharge roller pair 10.

  In Modification 3, the image before heating is read by the reading unit 13 and heated by the heating device 20. Thereafter, when the trailing edge of the sheet passes through the heating device 20 and the trailing edge detection sensor 9 detects that the trailing edge of the sheet has passed, the sheet is switched back and conveyed toward the reading unit 13 in the reverse direction. The When moving in the reverse direction, the sheet passes through the heating device 20 again. At this time, it is preferable not to heat the sheet by turning off the heating device 20 or providing another route so as not to pass through the heating device 20. Then, after the image after heating is read by the reading unit 13, it is determined whether or not the heat-erasable ink is used using the read pre-heating image data and post-heating image data. The sheet on which the image after heating is read by the reading unit 13 is discharged to the paper feed tray 2.

  Further, a trailing edge detection sensor is also provided between the reading unit 13 and the paper feed roller 4, and when the trailing edge of the sheet that has been reversely conveyed by the trailing edge detection sensor is detected, the sheet is switched back again. It may be discharged to the back part 17. In addition, the image after heating may be read by the reading unit 13 when the switchback is performed again and transported toward the switchback unit 17. When reading an image after heating during reverse conveyance, the image data after heating read by the reading unit 13 is image data with the trailing edge of the sheet as the head. Accordingly, when comparing the pre-heating image and the post-heating image, it is necessary to perform image processing such as rotating the post-heating image by 180 °. On the other hand, when the image is switched back again and conveyed toward the switchback unit 17, image processing such as rotating the image after heating by 180 ° is not required by reading the image after heating by the reading unit 13. There is a merit that it becomes.

  In the third modification, the heated sheet P is conveyed again to the reading unit 13 by switchback conveyance, so that the heated sheet P is conveyed to the reading unit 13 again in a loop shape. Thus, there is an advantage that the apparatus can be miniaturized.

[Modification 4]
FIG. 8 is a schematic configuration diagram of a heat-decoloring recording agent usage determination device 1c according to Modification 4.
In the fourth modification, the sheet is conveyed in the vertical direction.
In this modified example 4, the paper discharge tray 3 is disposed above the paper feed tray 2, and the sheet set in the paper feed tray 2 is conveyed vertically upward, and the pre-heating image is read by the pre-heating reading unit 11. It is read and heated by the heating device 20. Thereafter, the heated image is read by the after-heating reading unit 12 and then conveyed to the paper discharge tray 3. In addition, the determination unit 6a compares the pre-heating image data read by the pre-heating reading unit 11 with the post-heating image data read by the post-heating reading unit 12, and determines whether or not the heat-erasable ink is used. To do.

  In the above embodiment and Modifications 1 to 4, when a plurality of sheets are set in the sheet feeding tray 2 and it is determined whether or not the heat-erasable ink is used for the plurality of sheets, the determination unit Based on the determination result in 6a, the next sheet is conveyed. That is, when the determination result for the sheet discharged to the discharge tray 3 is a determination result that the heat-erasable ink is not used, the conveyance of the next sheet is started. On the other hand, if it is determined that the heat-erasable ink is used, the lamp 15 is turned on, a warning sound is emitted from the speaker 16 to notify the user, and the next sheet is not conveyed. When the user notices the notification from the lamp 15 or the speaker 16 and performs a predetermined process such as taking out the sheet on which the heat-erasable ink is written from the sheet discharge tray, and pressing the start button again, The conveyance is resumed, and the determination of whether or not the heat-erasable ink is used is resumed.

In addition, as shown in FIG. 9, a first discharge tray 3a that discharges a sheet that does not use heat-erasable ink, and a second discharge tray that discharges a sheet that uses heat-erasable ink. A paper tray 3b may be provided to divide the discharge destination.
In the configuration shown in FIG. 9, the distance from the post-heating reading unit 12 to the pre-branch conveyance roller pair 41 is longer than the length in the conveyance direction of the sheet to be determined. In FIG. 9, after the trailing edge of the sheet has passed through the post-heating reading unit 12, the leading edge of the sheet abuts against the pre-branch conveyance roller pair 41 and the conveyance is temporarily stopped. When the determination unit 6a determines that the heat-erasable ink is not used, the paper discharge switching claw 40 rotates in the clockwise direction in the drawing by a predetermined range so that the tip is positioned below. When the rotation of the paper discharge switching claw 40 is stopped, the drive of the pre-branch conveyance roller pair 41 is started, and the conveyance of the sheet is resumed. At this time, the sheet is guided to the first paper discharge tray 3a by the paper discharge switching claw 40 and discharged to the first paper discharge tray 3a.

  On the other hand, when the determination unit 6a determines that the heat-erasable ink is not used, the paper discharge switching claw 40 rotates in a predetermined range counterclockwise in the drawing so that the tip is positioned upward. When the rotation of the paper discharge switching claw 40 is stopped, the drive of the pre-branch conveyance roller pair 41 is started, and the conveyance of the sheet is resumed. At this time, the sheet is guided to the second sheet discharge tray 3b by the sheet discharge switching claw 40 and is discharged to the second sheet discharge tray 3b.

  As a result, a sheet that does not use heat-erasable ink and a sheet that uses heat-erasable ink are discharged to different paper discharge destinations. Therefore, when determining whether or not the heat-erasable ink is used for a plurality of sheets, if there is a sheet that uses the heat-erasable ink, it is not necessary for the user to perform the sorting process himself. Thereby, a highly convenient apparatus can be provided.

  In addition, by changing the discharge position to the discharge tray 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 the heat decoloring ink May be distinguished. In this case, for example, the discharge tray is configured to be movable in the sheet width direction. When the determination unit 6a determines that the heat-erasable ink is used, the discharge tray is moved from the specified position in the sheet width direction. Then, the sheet is conveyed to the paper discharge tray. On the other hand, when the determination unit 6a determines that the heat-erasable ink is not used, the discharge tray is positioned at a specified position. Thereby, the discharge position to the discharge tray can be made different in the sheet width direction between the sheet using the heat-erasable ink and the sheet not using it. In addition, the sheet discharge roller pair is configured to be movable in the sheet width direction, and the sheet discharge roller pair is moved in the sheet width direction during sheet conveyance using the heat-erasable ink. Thereby, the sheet discharge position of the sheet using the heat-erasable ink can be different from the sheet discharge position of the sheet using the heat-erasable ink in the sheet width direction.

FIG. 10 is a diagram illustrating an example of a display on the operation display unit 50.
FIG. 10A is a diagram illustrating an example of a display before the start of the heat decoloring ink determination, and FIG. 10B is a diagram illustrating an example of a display after the heat decoloring ink determination.
For example, when the user sets a sheet on the sheet feeding tray 2, an image as shown in FIG. 10A is displayed on the operation display unit 50. When the user touches the reading start button 50a displayed on the operation display unit 50, the heating / decoloring ink determination operation is started, and the sheet set on the sheet feeding tray 2 is conveyed. Then, as described above, the pre-heating image and the post-heating image are read, and it is determined whether or not the heating decoloring ink is used by the determination unit 6a described above. When the determination is performed by the determination unit 6a described above, the determination result is displayed on the operation display unit 50 as shown in FIG. When the decolorizing ink is used, “with decoloring” is displayed, and the read image before heating and the image after heating are displayed. Thus, by displaying the pre-heating image and the post-heating image on the operation display unit 50, 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. 10B, it can be confirmed that the heat decoloring ink was used in the description of the amount.

  Further, in the example shown in FIG. 10B, 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 50 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 50b to enlarge and display the portion where the heated decolored ink is used, as shown in FIG. It can be easily grasped.

  When the heat-erasable ink is used, the read pre-heat image data and post-heat image data are not erased from the memory 5 but are stored as they are. Then, by operating the operation display unit 50, the pre-heating image data and the post-heating image data stored in the memory 5 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. 12, a save setting image may be displayed on the operation display unit 50, and it may be set whether or not the read image is saved in the memory 5.

  When the document to be determined 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 50c. Thereby, even when it is determined by the determination unit 6a that the heat-erasable ink is used, the image data before heating and the image data after heating stored in each image information storage unit of the memory 5 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. 13 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 50 to execute the image range designation mode. When the apparatus 1 is used connected to a personal computer, an image range designation mode is executed from application software installed on the personal computer.

  When the image range specification mode is executed, the control unit 6 displays on the operation display unit 50 or the screen of the personal computer that a sheet for specifying the range is set in the paper feed tray 2 and the reading start button is pressed. When the user sets a sheet whose range is specified in the paper feed tray 2 and presses the reading start button, the sheet is conveyed and the image on the sheet is read into the reading unit 13. At this time, the heating device 20 is OFF. Then, the read image is displayed on the operation display unit 50 or the screen of the personal computer.

FIG. 14 is an example of a range setting screen displayed on the operation display unit 50.
As shown in FIG. 14, an image for designating the read range is displayed and a designated range setting screen 50d is displayed. A designation frame 50f 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 50d. “Upper” on the designated range setting screen corresponds to the position of the upper end of the designated frame 50f, and “Lower” on the designated range setting screen corresponds to the position of the lower end of the designated frame 50f. Further, “right” in the designated range setting screen corresponds to the right end position of the designated frame 50f, and “left” in the designated range setting screen corresponds to the left end position in the designated frame 50f. 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 50f moves upward, and the vertical direction of the designated frame 50f. The range expands. In this way, while confirming the image for which the range is designated and the designation frame 50f, a numerical value is input to the designated range setting screen “□” to designate 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 50e. When the designation end button 50e is pressed, the control unit 6 associates the image for which the range is designated with the designated range (the input up / down / left / right values) and stores them in the nonvolatile memory. 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. 14, the position is designated by the number of pixels (pixels), but the position may be designated 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.

  Thus, when the image range to be determined is designated, the pre-heating image and the post-heating image are read in the same manner as described above (S12, S13). At this time, the read range is the designated image range. Thereby, the data of the read image can be reduced. Next, the difference S for each color is calculated by the determination unit 6a (S14). In this case, the image data before and after heating is color-separated or binarized to calculate the number of pixels. However, since the image data is small, the calculation load is small and the difference S can be quickly calculated. 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 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. 14, 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. 14, 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 may be 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.

  As shown in FIG. 15, when the heating device 20 is arranged with a plurality of heating units 20 a arranged in a direction orthogonal to the paper transport direction and can partially heat the paper, the image range to be determined Only the heating section 20a 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.

FIG. 25 is a diagram showing an example of a heat-erasable recording agent use determination device that can detect whether or not heat-erasable ink has been used for both the front surface and the back surface of the sheet at once. FIG. 5 is a control block diagram for determining whether to use heat-erasable ink in this apparatus.
As shown in FIG. 25, a front surface heating pre-reading unit 11a and a back surface pre-heating pre-reading unit 11b are arranged between the heating device 20 and the paper feed roller 4. Further, between the heating device 20 and the sheet discharge roller 10, a post-surface heating reading unit 12a and a back-side heating post-reading unit 12b are arranged.

  In this apparatus, when the sheet is conveyed, the image before the front surface heating is read by the reading unit 11a before the surface heating, and the image before the back surface heating is read by the reading unit 11b before the back surface heating. The image before the front surface heating read by the reading unit 11a before the front surface heating is stored in the image information storage unit 500a before the surface heating in the memory 5 and read by the reading unit 11b before the rear surface heating. The pre-backside heating image is stored in the pre-backside heating image information storage unit 500 c of the memory 5.

  Next, after the sheet P is heated by the heating device 20 to a temperature at which the heat-erasable ink is decolored, the image after the front surface heating is read by the reading unit 12a after the front surface heating and the rear surface heating is performed. The post-heating image is read by the post-reading unit 12b. The image after the front surface heating read by the reading unit 12a after the front surface heating is stored in the image information storage unit 500b after the front surface heating in the memory 5, and is read by the reading unit 12b after the rear surface heating. The backside heated image is stored in the backside heated image information storage unit 500d of the memory 5.

  Next, the front surface heating image stored in the front surface heating image information storage unit 500a, and the front surface heating image stored in the front surface heating image information storage unit 500b, Is read. Then, the front surface determination unit 600a of the control unit 6 performs image processing similar to that described above, calculates the difference S, obtains the degree of change R, and determines whether the degree of change R exceeds the determination threshold T. A check is made to determine whether heat decoloring ink is used on the front side of the sheet.

  Further, the image before the backside heating stored in the image information storage unit 500c before the backside heating and the image after the backside heating stored in the image information storage unit 500d after the backside heating are read out. Then, the back side determination unit 600b of the control unit 6 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 lamp 15 may be used on either the front surface or the back surface of the sheet. Informs that heat-decoloring ink is being used.

  FIG. 27 is a diagram showing another example of a heat-erasable recording agent use determination device that can detect whether or not heat-erasable ink has been used for both the front surface and the back surface of a sheet at a time. 28 is a control block diagram of the heat decoloring ink use determination of another example.

  In another example shown in FIG. 27, the front surface reading unit 13a reads the images before and after heating the front surface of the sheet, and the back surface reading unit 13b reads the images before and after the heating of the front surface of the sheet. It is.

  In this apparatus, when the sheet is conveyed, the front surface heating image is read by the front surface reading unit 13a, and the pre-back surface heating image is read by the back surface reading unit 13b. The image before the front surface heating read by the front surface reading unit 13a is stored in the image information storage unit 500a before the surface heating in the memory 5, and the image before the back surface heating read by the back surface reading unit 13b. Is stored in the pre-backside heating image information storage unit 500 c of the memory 5.

  Next, after the sheet is conveyed to the loop conveyance path 7 and heated by the heating device 20 to a temperature at which the heat-erasable ink is decolored, the front surface reading unit 13a and the back surface reading unit 13b are again connected. It is transported to the place where it is placed. Then, the front surface heated image is read by the front surface reading unit 13a, and the rear surface heated image is read by the back surface reading unit 13b. The image after the front surface heating read by the front surface reading unit 13a is stored in the image information storage unit 500b after the front surface heating in the memory 5, and the back heated image read by the back surface reading unit 13b. Is stored in the post-heating back image information storage unit 500d of the memory 5.

  Thereafter, in the same manner as described above, the heat decoloring ink is used on the front surface of the sheet by the front surface determination unit 600a using the image before the front surface heating and the image after the front surface heating. It is determined whether or not. Further, using the pre-back surface heating image and the back surface post-heating image, the back surface determination unit 600b determines whether the heat decoloring 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 notifying unit such as the lamp 15 determines whether either the front surface or the back surface of the sheet is used. Informs that the heat-decoloring ink is used.

FIG. 29 is a diagram showing still another example of the heat-erasable recording agent use determination device that can detect whether or not the heat-erasable ink is used for both the front surface and the back surface of the sheet at once. FIG. 30 is a control block diagram of the heat-decoloring ink use determination of this another example.
In another example of the apparatus, one reading unit 13 reads an image before and after heating the front surface and an image before and after heating the back surface. In another example of the apparatus, a switchback unit 17 for switching back the seat is provided.

  In this apparatus, first, the image before surface heating is read by the reading unit 13 and stored in the image information storage unit 500 a before surface heating of the memory 5. Next, the sheet P is conveyed to the switchback unit 17, switched back by the switchback unit, and then conveyed to the loop conveyance path 7. At this time, the heating device 20 provided on the loop conveyance path 7 is OFF. Therefore, the sheet passes through the heating device 20 without being heated by the heating device 20 and is conveyed again to the reading unit 13. At this time, the sheet is reversed by the loop conveyance path, and conveyed to the reading unit 13 with the back surface facing up. Then, the image before the back surface heating is read by the reading unit 13 and stored in the image information storage unit 500 c before the back surface heating in the memory 5.

  Next, the sheet is conveyed again to the switchback unit 17 and then conveyed to the loop conveyance path 7. When the image before the back surface heating is read by the reading unit 13, the heating device 20 is turned on, and when the sheet transported to the loop transport path 7 again passes through the heating device 20, the heat decoloring ink is decolored. Heated to temperature. Thereafter, the sheet is reversed and conveyed to the reading unit 13 again with the front surface of the sheet facing upward. Then, the image after surface heating is read by the reading unit 13 and stored in the image information storage unit 500b after surface heating in the memory 5.

  Next, the sheet is conveyed again to the switchback unit 17 and then conveyed to the loop conveyance path 7. The sheet conveyed again to the loop conveyance path 7 passes through the heating device 20. When the heating device 20 can be heated to a temperature at which the heat-erasable ink is decolored up to the back surface of the sheet by one heating, the heating device 20 is turned off when the sheet passes. Thereby, the power consumption of the apparatus can be suppressed. On the other hand, in the case of a heating device that cannot be heated to the temperature at which the heat-erasable ink is decolored up to the back surface of the sheet with one heating, the heating device 20 is turned on to heat the sheet even when the sheet passes Is heated to a temperature at which the decolorizing ink is decolored. After reversing the sheet through the loop conveyance path, the sheet is conveyed to the reading unit 13 with the back surface facing up. The back heated image is read by the reading unit 13 and stored in the back heated image information storage unit 500 d of the memory 5, and the sheet on which the back heated image is read is discharged to the paper discharge tray 3.

  Thereafter, the processing is the same as described above. That is, using the image before the surface heating and the image after the surface heating, the front surface determination unit 600a determines whether 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 600b determines whether the heat decoloring 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 notifying unit such as the lamp 15 determines whether either the front surface or the back surface of the sheet is used. The fact that the heat-discoloring ink is used is reported.

Next, the heating device 20 will be described.
As the heating device 20, as shown in FIG. 16, a heat roller system configured by a pair of rollers and heating while conveying the sheet P can be used.
A heating device 20 shown in FIG. 16 includes a heating roller 101, a pressure roller 102 that forms a nip between the heating roller, and a thermal heater 103 as a heating unit. In FIG. 16, a heating control unit (not shown) for controlling the thermal heater is provided, and the thermal heater 103 is controlled based on detection information from the thermistor 104 that detects the surface temperature of the heating roller 101. 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. 17 is a diagram illustrating an example of a heating device 20 of a heat belt type. In this system, a heating belt 203 stretched between a pressure roller 202, a stretching roller 201, and a belt heating roller 204 is provided. A thermal heater 205 for heating the belt heating roller 204 is provided in the belt heating roller 204. Further, a thermistor 206 that detects the temperature of the heating belt 203 is provided. The heating belt 203 is rotated in the direction of arrow A in the figure to transmit the heat of the belt heating roller to the sheet P conveyed to the nip that contacts the pressure roller 202.
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 heating roller 101 and the heating belt 203 are heated by the heat of the thermal heater using a thermal heater. The roller and belt may be heated by induction heating.

FIG. 18 is a diagram illustrating an example of an induction heating type heating apparatus 20.
18 includes an induction heating unit 30 as a magnetic flux generation unit, a heating sleeve 22 as a heat generating member, a heating roller 21, a pressure roller 23, and the like.

Here, the heating sleeve 22 as a heat generating member is formed by sequentially forming an elastic layer 22b and a release layer 22c on a base material 22a 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 22a of the heating sleeve 22, a magnetic metal material such as iron, cobalt, nickel, or an alloy thereof can be used.
The elastic layer 22b of the heating sleeve 22 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 22c of the heating sleeve 22 is formed by coating a fluorine compound such as PFA in a tube shape, and its thickness is 50 μm. The heating roller 21 is formed by forming a heat-resistant elastic layer 21b made of a silicone foam on a cylindrical cored bar 21a made of a metal material such as stainless steel, and has an outer diameter of about 40 mm. The elastic layer 21b of the heating roller 21 is 9 mm thick and has an Asker hardness of 30 to 50 degrees on the shaft. The heating roller 21 is in contact with the inner peripheral surface of the heating sleeve 22 and holds the thin heating sleeve 22 in a roller shape.

  The pressure roller 23 is formed by sequentially forming a heat-resistant elastic layer 23b such as silicone rubber and a release layer (not shown) on a cored bar 23a made of a highly heat conductive metal material such as aluminum or copper. And the outer diameter is 40 mm. The elastic layer 23b 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 23 is in pressure contact with the heating roller 21 via the heating sleeve 22 and forms a nip portion at the pressure contact portion. Then, the sheet P is conveyed to the nip portion.

  The induction heating unit 30 as a magnetic flux generation unit includes an exciting coil 31, a core unit 32, a demagnetizing coil unit 33, and the like. The exciting coil 31 extends in the width direction (in the direction perpendicular to the paper in FIG. 18) 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 22. It is a thing. The demagnetizing coil unit 33 is disposed symmetrically with respect to the positional relationship corresponding to the sheet width direction, and is disposed so as to overlap the excitation coil 31. The core portion 32 is made of a ferromagnetic material such as ferrite (having a relative permeability of about 2500), and is provided with a center core 32b and a side core 32a in order to form an efficient magnetic flux toward the heating sleeve 22. . The core part 32 is installed so as to face the excitation coil 31 extending in the width direction.

The heating device 20 configured as described above operates as follows.
When the pressure roller 23 is driven to rotate counterclockwise in FIG. 18 by the drive motor, the heating sleeve 22 also rotates clockwise. At this time, the heating roller 21 holding the heating sleeve 22 is not actively driven to rotate. The heating sleeve 22 serving as the heat generating member and the heating member is heated by the magnetic flux generated from the induction heating unit 30 at a position facing the induction heating unit 30.

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 31, magnetic field lines alternate in both directions near the heating sleeve 22 facing the exciting coil 31. It is formed to switch to By forming an alternating magnetic field in this manner, an eddy current is generated in the base material 22a (heat generation layer) of the heating sleeve 22, and Joule heat is generated by the electrical resistance of the base material 22a and induction heating is performed.
Thus, the heating sleeve 22 is heated by induction heating of its own base material 22a.

  The surface of the heating sleeve 22 heated by the induction heating unit 30 reaches the nip portion with the pressure roller 23. 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 image before heating described above has been read is fed between the heating sleeve 22 and the pressure roller 23 while being guided by the guide plate 24 (by movement in the transport direction of the arrow Y1). is there). Then, the sheet P is fed from the nip portion while being heated by the heat received from the heating sleeve 22 and being separated from the heating sleeve 22 by the heating separation plate 25 and the pressure separation plate 26. The surface of the heating sleeve 22 that has passed through the nip portion then reaches the position facing the induction heating unit 30 again.

FIG. 19 is a diagram illustrating another example of the induction heating type heating apparatus 20.
FIG. 19 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. 19, a thermistor 306 is provided at the outlet 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. 18 and 19 is excellent in energy efficiency, and the waiting time until the set temperature can be shortened. Another feature is that temperature unevenness in the main scanning direction due to the heating means is eliminated.

FIG. 20 is a diagram illustrating another example of the heating device 20 that heats a sheet while conveying the sheet.
20 includes a pressure roller 611, a nip forming member 612, a heating belt 613, a metal pipe 615, 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. 21 is a diagram illustrating still another example of the heating device 20 that heats a sheet while conveying the sheet.
As shown in FIG. 21, the heating device 20 includes a heating sleeve 621 composed of a rotating endless belt, and a pressure roller 631 in contact with 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. Note that FIG. 21 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 621 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 shown in FIGS. 20 and 21 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.

Further, as shown in FIG. 22, a plurality of thermal heaters 403 may be arranged in the direction of the rotation axis of the heating roller 401, and the heating region may be divided and heated in the direction of the rotation axis.
In FIG. 22, 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. 15 above, 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. 22, the same configuration is possible even with the heat belt method.

  The heating device shown in FIGS. 21 and 22 can reduce the heat capacity as compared with the heat roller method, 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.

Although the heating device shown in FIGS. 16 to 22 is for heating the sheet while being conveyed, the sheet may be heated without contacting the sheet.
FIG. 23 is an example of a heating device that heats a sheet in a non-contact manner.
The heating device in FIG. 23 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. 24 is another example of a heating device that heats a sheet in a non-contact manner.
In FIG. 24, the sheet P is heated by the radiant heat of the heat source 502, and includes a heat source 502 and a reflector 503 surrounding 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 heat roller type heating device shown in FIG. 16, and the “heat belt” is the heat belt type heating device shown in FIG. “IH” is the heating device of the induction heating method shown in FIGS. 18 to 19, and “digital” is the heating device shown in FIG. Further, “warm air” is the heating device shown in FIG. 23, “radiant” is the heating device shown in FIG. 24, 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.

  Further, the image described with the heat-erasable ink disappears when heated by the heating device 20. 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.
(Aspect 1)
Heating means such as a heating device 20 for heating at least a part of the sheet, and image reading means for reading images on the sheet before and after heating by the heating means (in the present embodiment, constituted by one or a plurality of reading units); A heating / decoloring recording agent use determination apparatus comprising: a determination unit 6a determining unit that determines whether or not a heating decoloring recording agent is used based on image information before and after heating read by the image reading unit.
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.

(Aspect 2)
In (Aspect 1), an image information storage unit such as a pre-heating image information storage unit that stores image information before heating read by the image reading unit is provided.
According to this, as described in the embodiment, the heat-erasable recording agent such as the heat-erasable ink disappears due to the heating of the heating means such as the heating device 20. However, an image that has disappeared can be confirmed by storing the image information before heating in the image information storage means such as the image information storage unit 5a before heating. In addition, using the image information before heating stored in the image information storage unit, an image erased by heating by an image forming apparatus such as a printer can be reproduced on a sheet.

(Aspect 3)
In (Aspect 1) or (Aspect 2), a sheet conveyance unit that conveys a sheet and passes a heating unit such as the heating device 20 is provided, and the image reading unit is located upstream of the heating unit in the sheet conveyance direction, A pre-heating reading unit 11 that reads an image described on a sheet before heating, and a post-heating reading unit 12 that is positioned downstream of the heating unit in the sheet conveyance direction and reads an image described on the heated sheet. .
According to this, image information before heating and image information after heating can be read by one-pass conveyance that requires only one sheet passing, and the sheet conveyance path can be simplified, such as paper jam. Can be suppressed.

(Aspect 4)
In (Aspect 1) or (Aspect 2), after conveying the sheet in the order of the image reading unit such as the reading unit 13 of the image reading unit and the heating unit such as the heating device 20, the sheet is conveyed again to the image reading unit. Means.
According to this, as described in the second and third modifications, the image reading unit has one reading unit, and thus can read the image before heating and the image after heating. Thereby, compared with the case where the image before a heating and the image after a heating are read with a some reading part, the influence by the solid difference of a reading part does not come out. 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)
In (Aspect 4), the sheet conveying unit sequentially conveys the sheet to the image reading unit after the sheet sequentially passes through the image reading unit such as the reading unit 13 and the heating unit such as the heating device 20. Have a route.
According to this, as described in the second modification, unlike the case where the image is switched back and conveyed to the reading unit 13 again, when the image after heating is read, it can be read from the leading edge of the sheet. This eliminates the need for image processing such as rotating the read image information after heating by 180 ° to match the read image information before heating, and can easily compare images before and after heating.

(Aspect 6)
In (Aspect 4), after the sheet sequentially passes through the image reading unit such as the reading unit 13 and the heating unit such as the heating device 20, the sheet conveying unit is switched back to convey the sheet to the image reading unit. .
According to this, as described in the third modification, compared with the case where the sheet is conveyed in a loop shape and is conveyed again to the image reading unit such as the image reading unit 13, the image is taken without taking up the sheet conveyance space. It can be conveyed again to the reading unit, and the size of the apparatus can be reduced.

(Aspect 7)
In any one of (Aspect 1) to (Aspect 6), 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 a determination unit 6a, and a heat-erasable recording agent The sheet is discharged separately from the sheet determined not to be used.
According to this, as described with reference to FIG. 9, after determining whether or not a heat-erasable recording agent such as a heat-erasable ink is continuously used for a plurality of sheets, There is no need to sort a plurality of sheets discharged to the discharge destination into a sheet using a heat-erasable recording agent and a sheet not used. Thereby, a highly convenient apparatus can be provided.

(Aspect 8)
In (Aspect 7), the discharge destination of the sheet determined that the heat-erasable recording agent such as the heat-erasable ink is used by the determination unit such as the determination unit 6a, and the heat-erasable recording agent are not used. The sheet discharge destinations determined to be 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 9)
In any one of (Aspect 1) to (Aspect 8), a notification means such as a lamp 15 that notifies the user of the determination result determined by the determination means such as the determination unit 6a is provided.
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 10)
In (Aspect 9), the notification unit includes a display unit such as an operation display unit 50 that displays the determination result by the determination unit such as the determination unit 6a and / or the location where the heat-decoloring recording agent is used.
According to this, as described with reference to FIG. 10, it is possible to notify the user of the determination result and / or the location where the heat-erasable recording agent is used.

(Aspect 11)
In (Aspect 9) or (Aspect 10), the notification means includes sound generation means such as a speaker 16 that emits a sound when the determination means such as the determination unit 6a 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 checking the apparatus.

(Aspect 12)
In any one of (Aspect 1) to (Aspect 11), a display unit such as an operation display unit 50 for displaying image information before and after heating read by the image reading unit is provided.
According to this, as described with reference to FIG. 10, the difference between the images before and after heating can be confirmed from the image before heating displayed on the display means and the image after heating. 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 13)
In any one of (Aspect 1) to (Aspect 12), a determination unit such as the determination unit 6a grasps the number of pixels changed between before and after heating based on the images before and after heating read by the image reading unit. When the number of changed pixels is equal to or greater than the threshold value, it is determined that a heat-erasable recording agent such as heat-erasable ink 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 14)
In (Aspect 13), setting means such as an operation display unit 50 for setting a threshold value by the 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 15)
In (Aspect 1) to (Aspect 14), the determination unit such as the determination unit 6a performs color separation on each of the image information before and after heating read by the image reading unit, and a heat-erasable recording agent is used for each color. It is determined whether or not there is.
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 16)
In any one of (Aspect 1) to (Aspect 15), whether the determination unit such as the determination unit 6a uses a heat-erasable recording agent such as a heat-erasable ink for an image described in a predetermined range of the sheet. Judgment is made.
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 17)
In (Aspect 16), the determination unit such as the determination unit 6a includes a determination range specifying unit such as the operation display unit 50 that allows the user to specify a range in which it is determined whether or not the heat-erasable recording agent 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 18)
In any one of (Aspect 1) to (Aspect 17), 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 with reference to FIGS. 25 to 30, it is possible to determine whether or not the heat-erasable 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 with reference to FIG. 27, the image reading unit reads the image on the front side of the sheet. Unit 13a and a back side reading unit 13b that reads an image on the back side of the sheet. After the sheet is sequentially conveyed to each reading unit and the heating unit, the sheet is conveyed again to each reading unit, so that before and after the heating of both sides of the sheet The image can be read.
Further, as described with reference to FIG. 25, the image reading unit reads the image on the front surface of the sheet before heating, the front surface heating reading unit 11a, and the back surface that reads the image on the back surface of the sheet before heating. It is also possible to include a pre-heating reading unit 11b, a front surface heating reading unit 12a that reads an image on the heated sheet front surface, and a back surface heating reading unit 12b that reads an image on the back side of the heated sheet. Images before and after heating on both sides of the sheet can be read.
Furthermore, as described with reference to FIG. 29, the image reading unit is provided with 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. Can read the images before and after heating on both sides of the sheet with only one reading unit.

1: Heat-erasable recording agent use determination device 2: Paper feed tray 3: Paper discharge tray 3a: First paper discharge tray 3b: Second paper discharge tray 5: Memory 5a: Image information storage unit 5b before heating: Image after heating Information storage unit 6: control unit 6a: determination unit 7: loop transport path 11: pre-heating reading unit 11a: front surface heating pre-reading unit 11b: back surface pre-heating reading unit 12: post-heating reading unit 12a: front Reading unit after surface heating 12b: Reading unit after heating back surface 13: Reading unit 13a: Front surface reading unit 13b: Back surface reading unit 15: Lamp 16: Speaker 17: Switchback unit 20: Heating device 50: Operation display unit 500a : Image information storage unit 500b before the front surface heating: Image information storage unit 500c after the front surface heating: Image information storage unit 500d before the back surface heating: Image information storage unit 600a after the back surface heating: Front surface determination unit 600b : Back side judgment part

JP 2006-123324 A

Claims (18)

Heating means for heating at least a part of the sheet;
Image reading means for reading images on the sheet before and after heating by the heating means;
A heating / decoloring recording agent use determination apparatus comprising: a determination unit that determines whether or not a heating / decoloring recording agent is used based on image information before and after heating read by the image reading unit. . In the heat-decoloring recording agent use determination apparatus according to claim 1,
An apparatus for determining use of a heat-erased recording agent, comprising image information storage means for storing image information before heating read by the image reading means. In the heat-decoloring recording agent use determination apparatus according to claim 1 or 2,
A sheet conveying means for conveying the sheet and passing the heating means;
The image reading unit is positioned upstream of the heating unit in the sheet conveyance direction, and is a pre-heating reading unit that reads an image on the sheet before heating, and is positioned downstream of the heating unit in the sheet conveyance direction and is heated. A heating / decoloring recording agent use determination apparatus, comprising: a post-heating reading unit that reads an image on a subsequent sheet. In the heat-decoloring recording agent use determination apparatus according to claim 1 or 2,
An apparatus for determining use of a heat-erased recording material, comprising: a sheet conveying unit that conveys the sheet to the image reading unit again after conveying the sheet in the order of the image reading unit of the image reading unit and the heating unit. In the heat-decoloring recording agent use determination apparatus according to claim 4,
The heating / decoloring recording agent use determination apparatus, wherein the sheet conveying unit has a loop-shaped conveyance path that conveys the sheet that has passed through the image reading unit and the heating unit in this order to the image reading unit again. . In the heat-decoloring recording agent use determination apparatus according to claim 4,
The heating / decoloring recording agent use determination apparatus according to claim 1, wherein the sheet conveying unit performs switchback conveyance of the sheet that has passed through the image reading unit and the heating unit in this order, and conveys the sheet again to the image reading unit. In the heat-decoloring recording agent use determination apparatus according to any one of claims 1 to 6,
Heat decoloring characterized in that the sheet determined to be using the heat decoloring recording agent by the determining means and a sheet determined not to be using the heat decoloring recording agent are distinguished and discharged. Recording agent use determination device. In the heat-decoloring recording agent use determination apparatus according to claim 7,
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. Heat decoloring recording agent use determination device. In the heat-decoloring recording agent use determination apparatus according to any one of claims 1 to 8,
A heating / decoloring recording agent use determination apparatus, comprising: notification means for notifying a user of the determination result determined by the determination means. In the heat-decoloring recording agent use determination apparatus according to claim 9,
The heating / decoloring recording agent use determination apparatus, wherein the notification unit includes a display unit that displays a determination result by the determination unit and / or a heating / decoloring recording agent use location. In the heat-decoloring recording agent use determination apparatus according to claim 9 or 10,
The heating and decoloring recording agent use determination device, wherein the notification unit includes a sound generation unit that emits a sound when the determination unit determines that the heating and decoloring recording agent is used. In the heat-decoloring recording agent use determination apparatus according to any one of claims 1 to 11,
A heating / decoloring recording agent use determination apparatus comprising display means for displaying image information before and after heating read by the image reading means. In the heat-decoloring recording agent use determination apparatus according to any one of claims 1 to 12,
The determination means grasps the number of pixels whose pixel value has changed before and after heating based on the image information before and after heating read by the image reading means, and the number of pixels whose pixel value has changed is equal to or greater than a threshold value At this time, it is determined that a heat-erasable recording material is used, and the heat-erasable recording material use determination device. In the heat-decoloring recording agent use determination apparatus according to claim 13,
A heating / decoloring recording agent use determination apparatus, comprising: setting means for a user to set the threshold value. In the heat-decoloring recording agent use determination apparatus according to any one of claims 1 to 14,
The determination means performs color separation on each of the image information before and after heating read by the image reading means, and determines whether or not a heat-erasable recording agent is used for each color. Color recording agent use determination device. In the heat-decoloring recording agent use determination apparatus according to any one of claims 1 to 15,
The heat erasing recording agent use determination apparatus according to claim 1, wherein the determination means determines whether or not a heat erasing recording material is used for a predetermined range of the sheet. In the heat-decoloring recording agent use determination apparatus according to claim 16,
An apparatus for determining use of a heat-erasable recording agent, characterized in that the determination means comprises determination range specifying means for a user to specify a range in which it is determined whether or not a heat-erasable recording agent is used. In the heating / decoloring recording agent use determination apparatus according to any one of claims 1 to 17, the image reading unit reads images before and after heating on both sides of the sheet,
The determination means 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 means. Recording agent use determination device.

Images