JP2010094960A - Recording paper recycling apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recording paper recycling apparatus which can appropriately heat recording paper sheets according to a selected conveyance path. <P>SOLUTION: The recording paper recycling apparatus is composed of: a reading path selecting part which selects either a first conveyance path on which the recording paper sheets pass through an image erasing part and a reading part in this order or a second conveyance path on which the recording paper sheets pass through the reading part, the image erasing part, and the reading part in this order; an erasure determination part which determines whether the images are erased from the recording paper sheets on the basis of the read result by the reading part when the first conveyance path is selected, and which determines whether the images are erased from the recording paper sheets on the basis of the read result of the second time by the reading part when the second conveyance path is selected; a region distinguishing part which distinguishes a recording region on the basis of the first read result by the reading part when the second conveyance path is selected; and a heating control part which controls the image erasing part on the basis of the distinction result by the region distinguishing part. The image erasing part is arranged on a conveyance path common to the first and second conveyance paths. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a recording paper reproducing apparatus, and more particularly to a recording paper reproducing apparatus on which an image is recorded using a decoloring ink that is colorless by heating.

  2. Description of the Related Art In recent years, a printing apparatus that prints an image on recording paper using ink that becomes colorless by heating, and erases the image from the recording paper by heating the recording paper on which the image is printed using such ink. Has been proposed (for example, Patent Document 1). The ink that becomes colorless by heating is called a decoloring ink, and comprises a color former such as a leuco dye, a developer, and a decolorant. At normal temperature, the color former and developer are chemically bonded to form color, but when heated above a certain temperature, the chemical bond is inhibited by the action of the decolorizer and the color developer and developer are dissociated. To make it colorless. Since the image formed on the recording paper using such decoloring ink can be erased by heating the recording paper, the recording paper on which the image is recorded can be easily reused.

Therefore, it is conceivable to regenerate the recording paper by heating the recording paper on the conveyance path and erasing the image formed using the decoloring ink from the recording paper. Furthermore, it is conceivable that the recording paper after the heat treatment is read by a scanner to confirm the erasure of the image (for example, Patent Document 2). However, in Patent Documents 1 and 2 described above, a conveyance path for reading only one surface of a recording sheet by passing the reading unit that optically reads the recording sheet only once and a passage through the same reading unit are performed twice. There is no description about the case where the conveyance path for reading both surfaces can be selected.
JP 2001-302954 A JP 05-289575 A

  The present invention has been made in view of the above circumstances, and includes a first conveyance path that allows the reading unit to pass only once and reads only one side of the recording paper, and the same reading unit to pass twice. It is an object of the present invention to provide a recording paper recycling apparatus capable of appropriately performing a heating process on a recording paper in accordance with a second transport path for reading both sides of the recording paper. In particular, when the first transport path is selected, only erasure confirmation of an image recorded using decoloring ink or the like is performed, and when the second transport path is selected, a recording area in which an image is formed. An object of the present invention is to provide a recording paper recycling apparatus that can be heat-treated according to the above.

  According to a first aspect of the present invention, there is provided a recording paper reproducing apparatus comprising: a storage unit that stores a recording paper on which an image is recorded; a transport unit that transports the recording paper on a transport path from the storage unit to the discharge unit; A recording paper reproducing apparatus comprising: an image erasing unit that erases the image by heating on the conveyance path; and a reading unit that optically reads the recording paper on the conveyance path, wherein the recording paper is removed from the image erasing unit. And a first transport path that passes in the order of the reading unit, and a reading path selection unit that selects one of the second transport path that passes in the order of the reading unit, the image erasing unit, and the reading unit, and a first transport When the path is selected, it is determined whether or not the image is erased from the recording paper based on the reading result by the reading unit. When the second transport path is selected, the reading unit performs the second reading. Recording paper based on the results And when the second conveyance path is selected, a recording area in which the image is formed is determined based on a first reading result by the reading unit. And a heating control unit that controls the image erasing unit based on the determination result by the region determining unit, and the image erasing unit is transported in common to the first transport path and the second transport path. It is configured to be placed on the road.

  In this recording paper reproducing apparatus, one of a first conveyance path through which the recording paper passes in the order of the image erasing unit and the reading unit and a second conveyance path through which the recording paper passes in the order of the reading unit, the image erasing unit, and the reading unit are selected. When the first transport path is selected, image erasure confirmation based on the reading result by the reading unit is performed. On the other hand, when the second transport path is selected, image erasure confirmation is performed based on the second reading result by the reading unit, and an image is formed based on the first reading result by the reading unit. The recording area is determined, and the heat treatment is performed based on the determination result. According to such a configuration, when the first transport path is selected, only the erasure confirmation of the image recorded using the decoloring ink is performed, and when the second transport path is selected, the recording area Depending on the condition, heat treatment can be performed. Accordingly, a first conveyance path that allows the reading unit to pass only once and reads only one side of the recording paper, and a second conveyance path that allows the same reading unit to pass twice and read both sides of the recording paper. Accordingly, the recording paper can be appropriately heated.

  In addition to the above configuration, the recording paper recycling apparatus according to the second aspect of the present invention is configured such that the second conveyance path passes through the reading unit in the direction opposite to the first conveyance path, and then the first upstream of the image erasing unit. It is configured to be a conveyance path that merges with the conveyance path, passes through the image erasing unit, and then passes the reading unit again in the same direction as the first conveyance path.

  In addition to the above configuration, the recording paper recycling apparatus according to the third aspect of the present invention reverses the transport direction after the second transport path has passed the image erasing section and the reading section along the first transport path, and the recording paper is reversed. Is conveyed to the upstream side of the first conveying path from the image erasing unit, and is configured to be a conveying path through which the image erasing unit passes and then the reading unit again.

  According to the recording paper reproducing apparatus of the present invention, when the first transport path is selected, only the erasure confirmation of the image recorded using the decoloring ink is performed, and when the second transport path is selected. The recording area can be discriminated and heat treatment can be performed. Accordingly, a first conveyance path that allows the reading unit to pass only once and reads only one side of the recording paper, and a second conveyance path that allows the same reading unit to pass twice and read both sides of the recording paper. Accordingly, the recording paper can be appropriately heated.

Embodiment 1 FIG.
FIG. 1 is a diagram showing an example of a schematic configuration of a recording paper reproducing apparatus according to Embodiment 1 of the present invention, and shows a conveyance path of recording paper A1 on which an image is recorded. When the recording paper A1 on which the image is formed is heated on the transport path 4 to erase the color-erasable ink and erase the image, the recording paper recycling apparatus 1 confirms the erasure by optical reading of the recording paper A1. It is the reader which performs.

  The decolorizing ink is an ink that becomes colorless by heating, and a color former such as a leuco dye, a color developer that develops color by chemically bonding with the color former, and a color eraser for adjusting the color change temperature. Is dissolved or dispersed in a solvent. A color former such as a leuco dye is composed of an electron donating color developing compound, whereas a color developer is composed of an electron accepting compound. As this electron-accepting compound, for example, phosphoric acid ester of polyoxyethylene alkyl ether is used.

  Here, it is assumed that an image is recorded on the recording paper A1 using a decoloring ink that develops color in a temperature range of −20 ° C. or more and 80 ° C. or less and becomes colorless when heated to 80 ° C. or more.

  The recording paper recycling apparatus 1 includes an ADF (auto document feeder) unit 2 including a paper feed tray 3, separation rollers 11 to 13, a conveyance roller 5, a selector 21, a thermal head 22, and a light source unit 23, a light source unit 24, and an image. It is constituted by a flat bed unit 6 including a reading unit 25.

  In the recording paper recycling apparatus 1, the recording paper A 1 is taken out from the paper feed tray 3, separated one by one and sent to the transport path 4, and transported in the transport path 4 by the transport roller 5. Then, an image is read from the recording paper A1 by the image reading unit 25, and the read recording paper A1 is discharged to a discharge unit such as a discharge tray (not shown).

  The paper feed tray 3 is a storage unit that stores the recording paper A1 on which an image is recorded. The separation rollers 11 to 13 are rollers for separating the recording sheets A1 in the sheet feeding tray 3 one by one and sending them to the conveyance path 4.

  The separation roller 11 is a pickup roller that takes out the recording paper A1 in the paper feed tray 3 one by one by urging the recording paper A1 in the feeding direction, and sends the recording paper A1 from the paper feed tray 3 to the separation roller 12 side. Here, it is assumed that a large number of recording sheets A1 are stacked in the sheet feeding tray 3, and the uppermost recording sheet A1 is always in contact with the separation roller 11 regardless of the stacking amount of the recording sheets A1. .

  The separation roller 12 and the separation roller 13 are separation devices for separating the recording paper A1 sent by the separation roller 11 one by one and sending it to the conveyance path 4. The separation roller 12 is a separate roller for conveying the recording paper A1 in the feeding direction.

  The separation roller 13 is a retard roller for urging the recording paper A1 in the return direction, and is disposed opposite to the separation roller 12 so as to sandwich the recording paper A1 being conveyed. That is, the separation roller 12 is disposed on the upper side of the conveyance path 4, whereas the separation roller 13 is disposed on the lower side of the conveyance path 4. The separation roller 13 serves as a separation member that prevents the recording paper on the separation roller 13 side from being fed out of a plurality of overlapping recording sheets.

  In general, the separation performance when separating multiple recording sheets into one sheet depends on the magnitude relationship between the frictional force between the recording sheets and the frictional force between the recording sheets and the retard roller. Therefore, when the frictional force between the recording paper and the retard roller is large, the blocking force for preventing the recording paper from being fed increases, and the separation performance increases. That is, it can be separated one by one reliably. On the other hand, when the frictional force between the recording paper and the retard roller is small, the blocking force for preventing the recording paper from being fed is small and the separation performance is low. That is, it is easy to send out in a state where two or more sheets overlap.

  The separation roller 13 is provided with a torque limiter so as to be driven to rotate when a torque exceeding a certain level is applied.

  The transport roller 5 is a transport unit that transports the recording paper A1 in the transport path 4 in the feeding direction, and includes a pair of rollers arranged to face each other so as to sandwich the recording paper A1 being transported. The transport roller 5 is configured such that one roller is driven in the feeding direction by the drive unit and the other roller is driven to rotate.

  The thermal head 22 is an image erasing unit that decolorizes the decoloring ink by heating the recording paper A1 on the conveyance path 4 and erases an image recorded using the decoloring ink. Arranged on the side. The thermal head 22 is a heating head used when printing an image on recording paper, and is configured by, for example, arranging a plurality of heating elements on a straight line. The thermal head 22 can print an image by controlling each heating element and selectively heating the heating element. If such a thermal head 22 is used, heat can be selectively applied to one surface of the recording paper A1 on the conveyance path 4.

  The light source unit 23 is an illuminating device that irradiates the recording paper A1 on the conveyance path 4 with detection light during the reproduction process of the recording paper A1. The light source unit 24 is an illuminating device that irradiates the recording paper A1 on the conveyance path 4 with detection light when reading a document and when reproducing the recording paper A1.

  The image reading unit 25 is an optical reading device that optically reads the recording paper A1 on the transport path 4 and includes a light receiving sensor such as a CCD image sensor that receives detection light from the light source units 23 and 24. The image reading unit 25 is disposed on the opposite side of the light source unit 23 with the conveyance path 4 interposed therebetween. During the reproduction process of the recording paper A1, the detection light from the light source unit 23 that has passed through the recording paper A1 and Detection light from the light source unit 24 reflected by the recording paper A1 is received by the CCD image sensor.

  On the other hand, the light source unit 24 is arranged on the same side as the image reading unit 25 with respect to the recording paper A1 on the conveyance path 4, and the detection light reflected by the recording paper A1 is received by the CCD image sensor when reading the document. Is done. Here, the document reading is an operation mode in which image data read from the recording paper A1 by the CCD image sensor is output as document data. The light source unit 23 and the light source unit 24 are arranged on opposite sides of the conveyance path 4.

  In this recording paper recycling apparatus 1, as a conveyance path 4 from the paper feed tray 3 to the paper discharge tray, a first conveyance path where only reading for erasure confirmation is performed and a second conveyance where reading for heating control is also performed. Any of the paths can be selected.

  The first conveyance path is a conveyance path through which the recording paper A1 taken out from the paper feed tray 3 passes once in the order of the thermal head 22 and the image reading unit 25, and one side of the recording paper A1 when reading the document. It is a single-sided reading path that allows only one to be read.

  The second conveyance path is a conveyance path through which the recording paper A1 passes in the order of the image reading unit 25, the thermal head 22, and the image reading unit 25, and is a double-sided reading path for reading both sides of the recording paper A1 at the time of document reading. ing.

  After passing through the image reading unit 25, the second transport path merges with the first transport path on the upstream side of the thermal head 22, and is opposite to the first pass after passing through the thermal head 22. The transport path 4 passes through the image reading unit 25 again. That is, the second transport path passes through the image reading unit 25 in the opposite direction to the first transport path, and then merges with the first transport path on the upstream side of the thermal head 22 to allow the thermal head 22 to pass. After that, the conveyance path 4 through which the image reading unit 25 passes again in the same direction as the first conveyance path.

  Switching between the first conveyance path and the second conveyance path is performed by a selector 21 disposed on the downstream side of the separation rollers 12 and 13.

  The thermal head 22 is disposed on the transport path 4 common to the first transport path and the second transport path. Furthermore, the thermal head 22 is on the side opposite to the image reading unit 25 when passing the first time along the second transport path with respect to the recording paper A1 on the transport path 4, and when passing the second time. It is disposed at the same side as the image reading unit 25. Further, the light source unit 23 is disposed on the downstream side of the first transport path from the thermal head 22.

  FIG. 2 is a perspective view showing a configuration example of a main part of the recording paper recycling apparatus 1 of FIG. 1, and shows a state of the separation pressure adjusting mechanism 31 for the recording paper A1. The separation pressure adjusting mechanism 31 is a device that adjusts the pressing force of the separation roller 13 against the recording paper A1 in order to switch the operation mode when the recording paper A1 in the paper feed tray 3 is sent to the transport path 4.

  As such an operation mode, it is possible to select either a single-leaf mode in which the recording sheets A1 are sent one by one or a multi-leaf mode in which a plurality of recording sheets A1 are overlapped. By sending out a plurality of recording sheets A1 one by one, these recording sheets A1 can be erased collectively.

  The single-leaf mode here is basically an operation mode in which recording sheets are sent one by one. However, two or more recording sheets may be sent simultaneously due to erroneous conveyance, and are always sent one by one. Not necessarily. On the other hand, even in the multi-leaf mode, there is a case where only one recording sheet is sent out due to erroneous conveyance, and two or more recording sheets are not always sent out at the same time.

  The separation pressure adjusting mechanism 31 includes a roller holding portion 32 that supports the rotation shaft of the separation roller 13, a leg portion 33 that holds the roller holding portion 32 so as to be movable up and down, and a roller lifting portion 34 that raises and lowers the separation roller 13. Composed.

  The roller holding unit 32 holds the separation roller 13 horizontally. The leg 33 is fixed to the casing of the recording paper recycling apparatus 1 and holds the end of the roller holding part 32 opposite to the separation roller 13 side.

  The roller elevating unit 34 is a separation control unit that controls the frictional force between the separation roller 13 and the recording paper A1 based on the selected operation mode, and adjusts the frictional force by moving the separation roller 13 up and down. It is carried out. Specifically, the roller holding portion 32 is supported from the lower side by a movable portion whose height can be adjusted, and the separation roller 13 is moved up and down by adjusting the height of the movable portion. That is, the frictional force between the separation roller 13 and the recording paper A1 is increased by lifting the separation roller 13, and the frictional force is decreased by lowering the separation roller 13.

  In the double leaf mode, control is performed to lower the friction force between the separation roller 13 and the recording paper A1 by lowering the separation roller 13 and lowering the pressing force on the recording paper A1 than in the single leaf mode.

  FIG. 3 is a block diagram illustrating a configuration example of a main part of the recording paper reproduction apparatus 1 in FIG. 1, and illustrates an example of a functional configuration in the recording paper reproduction apparatus 1. In addition to the transport roller 5, the selector 21, the thermal head 22, the image reading unit 25, and the roller lifting / lowering unit 34, the recording paper recycling apparatus 1 includes an erasure determination unit 41, a notification unit 42, a transport control unit 43, and an area determination unit 46. And a head control unit 47, a paper feed mode selection unit 51, and a reading path selection unit 52.

  The erasure determination unit 41 performs an operation of determining whether or not an image has been erased from the recording paper A1 based on the output of the CCD image sensor of the image reading unit 25. Specifically, the received light amount of the detection light is compared with a predetermined threshold value, and it is determined whether or not the image is erased from the recording paper A1 based on the comparison result.

  The notification unit 42 performs an operation of notifying an erasure error based on the determination result by the erasure determination unit 41. For example, when the image has not been sufficiently erased from the recording paper A1, a message indicating that the erasure is insufficient is displayed on a display unit (not shown). Accordingly, since an erasure error is notified based on the determination result of whether or not the image has been erased from the recording paper A1, the user can easily identify the recording paper A1 in which the image has not been sufficiently erased. .

  The conveyance control unit 43 controls the conveyance roller 5 and performs an operation of selecting whether or not the recording paper A1 is conveyed again to the image erasing unit 26 based on the determination result by the erasure determination unit 41. For example, when the image is not sufficiently erased, an operation of switching back at the position of the discharge roller and transporting the recording paper A1 to the image erasing unit 26 again is performed.

  Here, the notification unit 42 may be configured to notify an erasure error when the heating process for the same recording paper A1 exceeds a certain number of times. As a result, when the image is not sufficiently erased even after a certain number of heat treatments, an erasure error is notified, so that the image can be surely erased and is recorded by a recording material that does not disappear even if the image is heated. In this case, the user can be made aware of that.

  The head control unit 47 is a heating control unit that controls the thermal head 22 based on the output of the CCD image sensor of the image reading unit 25. In the head controller 47, the thermal head 22 is controlled based on the determination result by the erasure determination unit 41, and the operation of decolorizing the decolored ink by heating the re-conveyed recording paper A1 is performed. That is, the re-conveyed recording paper A1 is heated again by the thermal head 22, and after the heating process, it is read by the image reading unit 25, and erasure confirmation is performed again based on the reading result.

  As a result, whether or not the recording paper A1 is conveyed again to the thermal head 22 is selected based on the determination result of whether or not the image has been erased from the recording paper A1, and therefore the recording paper on which the image has not been sufficiently erased. The second heat treatment for A1 can be automatically performed.

  The area determination unit 46 performs an operation of determining a recording area in which an image is formed based on the output of the CCD image sensor of the image reading unit 25. Specifically, based on the image data read from the recording paper A1 by the CCD image sensor, an operation for discriminating an area on the paper surface on which characters or the like are formed as the recording area is performed. That is, this recording area is determined based on the light reception result of the detection light transmitted through the recording paper.

  In this area discriminating unit 46, by comparing the received light amount of the detection light with a plurality of threshold values, images are formed on both sides of the recording paper A1, or images are formed only on one side, or Then, an operation for determining whether an image is formed on any surface is performed.

  Here, when the image forming surface is determined based on the detection light transmitted through the recording paper A1, if an image is formed on the image reading unit 25 side of the recording paper A1, the image is formed on the opposite surface. It is conceivable that it cannot be detected whether or not it is formed. In such a case, an image is formed at least on the surface of the recording paper A1 on the image reading unit 25 side, an image is formed only on the surface opposite to the image reading unit 25, or It may be possible to determine whether an image is also formed on the surface.

  The head control unit 47 performs an operation of controlling the thermal head 22 so that the recording area determined by the area determination unit 46 becomes a heating area on the recording paper A1. For example, when an image is formed only on a part of the recording paper A1, an operation of heating the image forming part is performed by controlling the thermal head 22 spatially or temporally.

  Specifically, when an image is formed only in either the upstream region or the downstream region of the recording paper A1, the heating timing is adjusted so that the image forming portion is heated.

  Alternatively, when an image is formed only on either the right side region or the left side region of the recording paper A1, the heating element of the thermal head 22 is selectively heated so that the image forming portion is appropriately heated. Control is performed. That is, by using the thermal head 22 as the image erasing unit, the heating area can be controlled at a minute level, that is, on a heating element basis. Therefore, for example, by generating a copy image based on the read image read by the image reading unit 25 and controlling the thermal head 22 based on the copy image, only the image forming portion can be heated. Power consumption related to the heat treatment can be minimized.

  Thus, since the heating area is adjusted according to the recording area during the heating process of the recording paper A1, the power consumption related to the heating process is suppressed as compared with the case where the entire recording paper A1 is always the heating area. be able to.

  Further, the head controller 47 performs control to vary the amount of heat applied to the recording paper A1 according to the image forming surface determined by the region determining unit 46. Specifically, when an image is formed only on the surface of the recording paper A1 on the thermal head 22 side, that is, the surface opposite to the image reading unit 25, an image is formed on both surfaces. The operation of reducing the amount of heat applied to the recording paper A1 by reducing the amount of heat per unit area of the thermal head 22 is performed. That is, when the thermal head 22 is disposed on the opposite side of the image reading unit 25 across the conveyance path 4, an image is formed only on the surface of the recording paper A1 opposite to the image reading unit 25. In this case, the operation of reducing the amount of heat per unit area of the thermal head 22 is performed more than when an image is formed on at least the surface of the recording paper A1 on the image reading unit 25 side.

  Differentiating the amount of heat applied to the recording paper A1 controls, for example, the duty ratio and line cycle between the time when the thermal head 22 is on and the time when it is off within the conveyance time for one line. Can be realized. For example, in order to reduce the amount of heat per unit area of the thermal head 22, the time during which the thermal head 22 is on may be relatively shortened.

  Thereby, when an image is formed only on the surface of the recording paper A1 on the thermal head 22 side, an image is formed on both surfaces, or an image is formed only on the surface opposite to the thermal head 22. Since the head temperature is lower than in any case where the head is formed, the head temperature is fixed in accordance with at least the case where the image is formed on the surface opposite to the thermal head 22. Power consumption related to the heat treatment can be suppressed.

  The paper feed mode selection unit 51 operates as a mode for sending the recording paper A1 in the paper feed tray 3 to the transport path 4, and a single-leaf mode for sending the recording paper A1 one by one and a multi-leaf mode for sending a plurality of sheets. The operation to select one of is performed.

  The roller elevating unit 34 performs an operation for elevating the separation roller 13 based on the operation mode selected by the paper feed mode selection unit 51. By raising and lowering the separation roller 13, the pressing force of the separation roller 13 on the recording paper A1 can be adjusted.

  In the head controller 47, when the multi-leaf mode is selected, an operation is performed to increase the amount of heat per unit area given to the recording paper A1 as compared with the single-leaf mode. Specifically, when the multi-leaf mode is selected, an operation is performed in which the amount of heat applied to the recording paper A1 is increased by increasing the amount of heat per unit area of the thermal head 22 compared to the case of the single-leaf mode. In order to increase the amount of heat per unit area of the thermal head 22, for example, the time during which the thermal head 22 is on may be relatively increased. If necessary, the line cycle may be lengthened.

  The reading path selection unit 52 performs an operation of controlling the selector 21 and selecting one of the first conveyance path and the second conveyance path.

  When the first conveyance path is selected, the erasure determination unit 41 determines whether or not the image has been erased from the recording paper A1 based on the reading result by the image reading unit 25, and the second conveyance path is selected. In this case, an operation is performed to determine whether or not the image is erased from the recording paper A1 based on the second reading result by the image reading unit 25.

  On the other hand, the area determination unit 46 performs an operation of determining the recording area based on the first reading result by the image reading unit 25 when the second conveyance path is selected.

  In the recording paper reproducing apparatus 1, any one of the high speed erasing mode, the normal erasing mode, and the low power erasing mode can be selected. As the normal erasure mode, the first conveyance path (single-sided reading path) and the single-leaf mode are selected, and only the erasure confirmation of the image is performed.

  In the high-speed erasing mode, the first conveyance path (single-sided reading path) and the multi-leaf mode are selected, and only the erasure confirmation of the image is performed. Since the high-speed erasing mode is an operation mode in which a plurality of recording papers A1 are collectively erased and confirmed to be erased collectively, the time required for the reproduction processing of the recording paper A1 can be shortened compared to the normal erasing mode. .

  In the low power erasing mode, the second conveyance path (double-sided reading path) and the single-leaf mode are selected, and heating control based on the determination result of the recording area and image erasure confirmation are performed. In this low power erasing mode, the heating area is adjusted according to the recording area, so that the power consumption related to the heat treatment can be suppressed as compared with the high speed erasing mode and the normal erasing mode.

  FIGS. 4A to 4C are explanatory views schematically showing an example of the operation of the recording paper reproducing apparatus 1 of FIG. 1, in which the image reading unit 25 has the horizontal axis as the amount of received light and the vertical axis as the frequency. Shows the density distribution of the read image read from the recording paper A1. FIG. 4A shows a density distribution of a read image obtained by receiving detection light from the light source unit 24 reflected by the recording paper A1 when images are formed on both sides of the recording paper A1. Has been. FIG. 4B shows a density distribution of a read image obtained by receiving detection light from the light source unit 23 that has passed through the recording paper A1. FIG. 4C shows the density distribution of the read image obtained when the light sources 23 and 24 are turned on simultaneously.

  In the case of a read image obtained by receiving detection light emitted from the light source unit 24 and reflected by the recording paper A1, that is, in the case of FIG. 4A, the surface (front surface) of the recording paper A1 on the image reading unit 25 side. ) Light is strongly absorbed by the decoloring ink. For this reason, the density distribution of the read image is a distribution having a maximum point of frequency on the side where the received light amount is smaller than a certain level, that is, on the side where the density is higher (darker) and on the side where the received light amount is larger than the certain level. Become.

  Assuming that the frequency threshold for determining whether or not an image is recorded on the sheet is Th1, the maximum on the side where the amount of received light is smaller than the predetermined density threshold Th2 among the maximum points where the frequency exceeds Th1. The peak position of the point is the received light amount P1.

  On the other hand, as maximum points on the side with a large amount of received light, a maximum point (light reception amount P2) corresponding to the background color (ground color) portion and a maximum point (light reception amount P3) corresponding to show-through are formed. (P3 <P2). The show-through refers to the back surface of the recording paper A1 that has been read by the light transmitted through the recording paper A1 after passing through the recording paper A1 and reflected by the ADF unit 2 out of the detection light emitted from the light source unit 24. It is the image of.

  In general, the transmittance when the detection light passes through the recording paper A1 is different depending on whether the decoloring ink is present on the front surface or the back surface of the recording paper A1. For this reason, the maximum point of the show-through is located on the higher density side than the maximum point of the background color portion, but the difference in density is the maximum point of the surface image (the amount of received light P1) and the maximum point of the background color portion. Smaller than the difference in density.

  Furthermore, since the density difference changes depending on the paper thickness, it is difficult to determine whether or not an image is formed on the back surface of the recording paper A1 in a read image obtained by receiving reflected light. That is, as the thickness of the recording paper A1 increases, the show-through maximum point approaches the maximum point of the background color portion, so that it is difficult to determine whether there is show-through.

  On the other hand, the difference in density between the maximum point of the surface image and the maximum point of the background color portion is sufficiently large, so whether or not the maximum point exceeding the frequency threshold Th1 exists on the side smaller than the density threshold Th2. It is possible to identify whether or not an image is formed on the surface of the recording paper A1.

  In the case of a read image obtained by receiving detection light emitted from the light source unit 23 and transmitted through the recording paper A1, that is, in the case of FIG. 4B, the decoloring ink exists only on the surface of the recording paper A1. The difference in transmittance between the case where it exists, the case where it exists only on the back surface, and the case where it exists on both sides is small. For this reason, the maximum points corresponding to the image on the front surface and the image on the back surface overlap each other on the side where the amount of received light is smaller than a certain level.

  The maximum point at which the frequency exceeds Th1 corresponds to the maximum point (light reception amount P4) whose received light amount is smaller than the density threshold Th2 and the background color portion, and the maximum point (light reception) where the received light amount is larger than the density threshold Th2. Amount P5).

  Next, in the case of a read image obtained by simultaneously turning on the light sources 23 and 24 and receiving the detection light reflected by the recording paper A1 and the detection light transmitted through the recording paper A1, that is, FIG. In this case, the maximum point (the amount of received light P6) of the background color portion has moved to the side with the larger amount of received light compared to FIG.

  For this reason, the difference in density between the show-through maximum point and the background color portion becomes large, and it is easy to determine whether or not there is show-through. That is, whether or not an image is formed on the back surface of the recording paper A1 is determined by determining whether or not a maximum point exceeding the frequency threshold Th1 exists between the density threshold Th2 and the predetermined density threshold Th3. can do. Therefore, by analyzing the density distribution of such a read image, whether the image is formed at least on the front surface of the recording paper A1, only on the back surface, or formed on any surface. Can be correctly identified.

  As can be seen from FIGS. 4A to 4C, both the reflected light and the transmitted light are simultaneously received, and the brightness of each light source unit 23, 24 is controlled, whereby the position of each peak in the density distribution. Can be controlled. Therefore, highly accurate detection can be performed by controlling the brightness of the light source units 23 and 24 when receiving both the reflected light and the transmitted light at the same time.

  In the present embodiment, regarding the temperature control of the thermal head 22, the thermal head 22 is arranged on the side opposite to the image reading unit 25 with respect to the recording paper A <b> 1 being conveyed, thereby depending on the density of the image read by the image reading unit 25. Thus, the temperature of the thermal head 22 can be adjusted appropriately. Specifically, when the density of the read image is higher than a certain level, that is, when the amount of received light is smaller than the certain level, an image is formed on the image reading unit 25 side, that is, the surface opposite to the thermal head 22. Therefore, the control to increase the heating temperature of the recording paper A1 is performed.

  On the other hand, when the density of the read image is lower than a certain level, that is, when the amount of received light is larger than the certain level, an image is formed on the surface opposite to the image reading unit 25, that is, the surface on the thermal head 22 side. Therefore, control is performed to lower the heating temperature of the recording paper A1.

  Regarding the adjustment of the heating area by the thermal head 22, the heating area on the recording paper A1 is appropriately adjusted by discriminating the image recording area and the margin part based on the density of the image read by the image reading unit 25. be able to. Specifically, control for adjusting the heating timing by the thermal head 22 is performed so that the recording area on the recording paper A1 is appropriately heated, or control for selectively generating heat from the heating elements of the thermal head 22. Is done.

  According to the present embodiment, the intensity of light transmitted through the recording paper A1 is different at least when an image is formed on one side of the recording paper A1 and when no image is formed on any side. This is used to confirm image erasure. For this reason, even in the case of the recording paper A1 on which images are formed on both sides, it is possible to confirm the erasure of the image by one reading. Therefore, the recording paper A1 after the erasing process can be performed without complicating the configuration of the apparatus and without increasing the time required for the reproduction process of the recording paper A1 as compared with the apparatus that receives the reflected light from the recording paper. It is possible to confirm deletion of an image.

  Further, heating control of the recording paper A1 is performed based on the output of the light receiving sensor that receives the detection light transmitted through the recording paper A1. According to such a configuration, the heating control can be appropriately performed according to the density of the read image read by the light receiving sensor. At that time, utilizing the fact that the intensity of the light transmitted through the recording paper A1 is different at least when an image is formed on one side of the recording paper and when no image is formed on any side, By determining the density of the read image, it is appropriate without complicating the configuration of the apparatus and increasing the time required for the recording paper reproduction process, compared with the case of receiving reflected light from the recording paper. Can be heat-treated.

Embodiment 2. FIG.
In the first embodiment, the second transport path passes through the image reading unit 25 in the direction opposite to the first transport path, and then merges with the first transport path on the upstream side of the thermal head 22. An example has been described in which the image reading unit 25 is again passed in the same direction as the first conveyance path after passing through 22. On the other hand, in the present embodiment, the second transport path passes the thermal head 22 and the image reading unit 25 along the first transport path, and then reverses the transport direction to transfer the recording paper A1 to the thermal head 22. A case where the transport path is transported to the upstream side of the first transport path will be described.

  FIG. 5 is a diagram showing a configuration example of the recording paper reproducing apparatus 60 according to the second embodiment of the present invention, and shows a conveyance path of the recording paper A1 on which an image is recorded. In the recording paper recycling apparatus 60, the second transport path passes the thermal head 22 and the image reading unit 25 along the first transport path, and then reverses the transport direction so that the recording paper A1 is more than the thermal head 22. The transport path is transported upstream of the first transport path, passes through the thermal head 22, and then passes through the image reading section 25 again.

  In the second transport path, after passing through the image reading unit 25, the transport direction of the recording paper A1 is reversed, merges with the first transport path on the upstream side of the thermal head 22, and passes through the thermal head 22. The transport path 4 passes through the image reading unit 25 again in the same direction as the first pass.

  The thermal head 22 is disposed on the transport path 4 common to the first transport path and the second transport path. Furthermore, the thermal head 22 is on the side opposite to the image reading unit 25 when passing the first time along the second transport path with respect to the recording paper A1 on the transport path 4, and when passing the second time. It is disposed at the same side as the image reading unit 25. Further, the light source units 23 and 24 are disposed on the downstream side of the first transport path from the thermal head 22.

  When the second transport path is selected, the recording paper A1 is transported in the order of the thermal head 22, the image reading unit 25, the thermal head 22, and the image reading unit 25. In such a configuration, when passing through the thermal head 22 for the first time, the entire paper surface of the recording paper A1 is heated as a heating area, and based on the first read image, the erasure determination and the recording area of the image are recorded. Make a distinction. Then, when passing the thermal head 2 for the second time, the heating area of the recording paper A1 is adjusted based on the determination result of the recording area, and the erasure determination is performed again based on the second read image. Conceivable. In this way, the heat treatment can be performed most efficiently.

  In the first and second embodiments, when the second transport path is selected, the same image reading unit 25 is passed twice so that the reading result of the recording paper A1 can be determined as the recording area and the image erasure confirmation. Although an example in the case of being used for the above has been described, the present invention is not limited to this. For example, two image reading units 25 may be arranged on the conveyance path 4, and the reading results by these image reading units 25 may be used for recording area discrimination and image erasure confirmation, respectively.

  FIG. 6 is a diagram showing a configuration example of a recording paper reproducing apparatus 70 according to another embodiment of the present invention, and shows a conveyance path of the recording paper A1 on which an image is recorded. In the recording paper recycling apparatus 70, the conveyance path 4 is a conveyance path through which the recording paper A1 passes in the order of the first image reading unit 25, the thermal head 22, and the second image reading unit 25.

  The thermal head 22 is disposed on the side opposite to the first image reading unit 25 with respect to the recording paper A1 on the transport path 4.

  In the recording paper reproducing apparatus 70, the recording area is determined based on the reading result by the first image reading unit 25, and the erasure confirmation of the image is performed based on the reading result by the second image reading unit 25.

  In the first and second embodiments, the example in which the thermal head 22 for heating one surface of the recording paper A1 is disposed only on one side of the transport path 4 has been described. However, the present invention is not limited to this. It is not something that can be done. The present invention can also be applied to those in which the thermal head 22 is disposed on both sides of the transport path 4. When the thermal head 22 is provided on both sides with respect to the recording paper A1 on the conveyance path 4, the heating temperature can be lowered as compared with the case where it is provided only on one side.

  In the first and second embodiments, an example in which the thermal head 22 is used as the image erasing unit has been described. However, instead of the thermal head 22, a halogen heater that heats the recording paper A1 by radiant heat, or conduction heat is used. A heat roller that heats the recording paper A1 may be used.

  In the first and second embodiments, an image is formed only on the surface of the recording paper A1 on the thermal head 22 side, and an image is formed on at least the surface opposite to the thermal head 22. In the above description, an example in which the amount of heat per unit area of the thermal head 22 is varied has been described, but the present invention is not limited to this. The amount of heat applied to the recording paper A1 is different between the case where an image is formed only on the surface of the recording paper A1 on the thermal head 22 side and the case where an image is formed on at least the surface opposite to the thermal head 22. Other configurations are possible as long as they are possible. For example, when the image is formed only on the surface of the recording paper A1 on the thermal head 22 side and when the image is formed on at least the surface opposite to the thermal head 22, the conveyance speed of the recording paper A1 is increased. The amount of heat applied to the recording paper A1 by the thermal head 22 may be varied by changing the temperature.

  Moreover, although Embodiment 1 and 2 demonstrated the example in case the separation roller 13 was used as a separation member, this invention is not limited to this. For example, a member that prevents the recording paper A1 from being fed by pressing a plate-like separation pad against the recording paper A1 may be used as the separation member.

  In the first and second embodiments, the example in which the frictional force between the separation roller 13 and the recording paper A1 is adjusted by changing the pressing force of the separation roller 13 on the recording paper A1 has been described. It is not limited to this. For example, separation members having different surface materials may be selectively switched according to the operation mode. Alternatively, a separation member that can change the contact area with the recording paper A1 may be used, and the contact area may be changed according to the operation mode.

  In Embodiments 1 and 2, if it is determined that the image is formed only on the back surface of the recording paper A1, that is, the surface on the thermal head 22 side, the image is formed on the front surface of the recording paper A1. Although an example in which heat treatment is performed with less heat applied to the recording paper A1 than in the case has been described, the present invention is not limited to this. For example, in the case where an image with a low density is formed on the front surface of the recording paper A1, there is a possibility that it is erroneously determined that the image is formed only on the back surface of the recording paper A1. In such a case, it is conceivable that the image is not sufficiently erased by reducing the amount of heat applied to the recording paper A1 during the heat treatment.

  Therefore, when it is determined that the image is not erased in the erasure confirmation after the heating processing for the recording paper A1 in which it is determined that the image is formed only on the back surface of the recording paper A1, in the subsequent reheating processing, For example, even if it is determined in the pre-check that the image is formed only on the back side, it is conceivable that the amount of heat applied to the recording paper A1 is made larger than that in the first heat treatment. That is, in the first heat treatment, if it is determined by the preliminary check based on the read image that the image is formed only on the back surface, the amount of heat applied to the recording paper A1 is larger than that in the case where the image is formed on the front surface. However, if it is determined that the image has not been sufficiently erased in the subsequent erasure confirmation, control is performed to increase the amount of heat applied to the recording paper A1 in the second and subsequent heating processes. For example, during the second and subsequent heat treatments, the amount of heat applied to the recording paper A1 is controlled to be the same level as when an image is formed on the surface.

  According to this configuration, it is possible to prevent the erasure error from being repeatedly generated in the case where an image with a low density is formed on the surface of the recording paper A1, and thus the power consumption can be suppressed.

1 is a diagram illustrating an example of a schematic configuration of a recording paper reproduction apparatus according to Embodiment 1 of the present invention, and illustrates a conveyance path of a recording paper A1 on which an image is recorded. FIG. 2 is a perspective view illustrating a configuration example of a main part of the recording paper recycling apparatus 1 in FIG. 1 and illustrates a state of a separation pressure adjusting mechanism 31 for the recording paper A1. FIG. 2 is a block diagram illustrating a configuration example of a main part of the recording paper playback apparatus 1 in FIG. FIG. 2 is an explanatory diagram schematically showing an example of the operation of the recording paper reproducing apparatus 1 of FIG. 1, and shows the density distribution of a read image read from the recording paper A1 by the image reading unit 25. FIG. 6 is a diagram illustrating a configuration example of a recording paper reproducing apparatus 60 according to a second embodiment of the present invention, and illustrates a conveyance path of a recording paper A1 on which an image is recorded. FIG. 10 is a diagram illustrating a configuration example of a recording paper reproducing apparatus according to another embodiment of the present invention, and illustrates a conveyance path of a recording paper A1 on which an image is recorded.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Recording paper reproduction | regeneration apparatus 2 ADF part 3 Paper feed tray 4 Conveyance path 5 Conveyance roller 6 Flat bed parts 11-13 Separation roller 21 Selector 22 Thermal head 23, 24 Light source part 25 Image reading part 31 Separation pressure adjustment mechanism 32 Roller holding part 33 Leg 34 Roller Lifting Unit 41 Deletion Discrimination Unit 42 Notification Unit 43 Transport Control Unit 46 Area Discrimination Unit 47 Head Control Unit 51 Paper Feed Mode Selection Unit 52 Reading Path Selection Unit A1 Recording Paper

Claims (3)

A storage unit that stores recording paper on which an image is recorded, a transport unit that transports the recording paper on the transport path from the storage unit to the discharge unit, and erasing the image by heating the recording paper on the transport path In a recording paper reproducing apparatus having an image erasing unit that performs and a reading unit that optically reads the recording paper on the conveyance path,
Reading that selects one of a first conveyance path through which the recording paper passes in the order of the image erasing unit and the reading unit, and a second conveyance path through which the reading unit, the image erasing unit, and the reading unit are sequentially passed. A path selector;
When the first transport path is selected, it is determined whether or not an image has been erased from the recording paper based on the reading result by the reading unit. When the second transport path is selected, 2 by the reading unit. An erasure discrimination unit for discriminating whether or not the image has been erased from the recording paper based on the result of the second reading;
An area discriminating unit for discriminating a recording area in which the image is formed based on a first reading result by the reading unit when the second transport path is selected;
A heating control unit for controlling the image erasing unit based on a determination result by the region determining unit;
The recording paper reproducing apparatus, wherein the image erasing unit is disposed on a conveyance path common to the first conveyance path and the second conveyance path.   After the second conveyance path passes through the reading unit in the direction opposite to the first conveyance path, the first conveyance path merges with the first conveyance path on the upstream side of the image erasing unit, passes through the image erasing unit, and then passes through the first erasing unit. The recording paper reproducing apparatus according to claim 1, wherein the recording paper reproduction apparatus is a conveyance path through which the reading unit passes again in the same direction as the conveyance path.   The second transport path passes the image erasing unit and the reading unit along the first transport path, and then reverses the transport direction to transport the recording paper to the upstream side of the first transport path from the image erasing unit, The recording paper reproducing apparatus according to claim 1, wherein the recording paper reproducing apparatus is a conveyance path through which the image erasing unit passes and then the reading unit again.

Images