JP2018116311A - Image forming apparatus - Google Patents

Abstract

A problem to be solved by an embodiment of the present invention is to prevent erasing of a sheet that an operator does not want to erase in an image forming apparatus capable of erasing a sheet on which an image is formed with erasable ink. An image forming apparatus capable of doing this is provided. The image forming apparatus includes a heating unit that heats a recording medium and a pressurizing unit. The fixing process fixes an image formed of a color erasable material on the recording medium at a fixing temperature, or erases the image at an erasing temperature. A fixing unit that executes an erasing process to be performed, a reading unit that is arranged on the upstream side of the fixing unit in the conveyance direction of the recording medium, and that reads an identifier indicating whether or not the color material of the image formed on the recording medium can be erased, and An image forming apparatus comprising: a control unit that controls execution of an erasing process of an image on a recording medium by the fixing device based on a reading result of the identifier by the reading unit. [Selection] Figure 1

Description

  Embodiments described herein relate generally to an image forming apparatus.

  As one form of an image forming apparatus, an image is printed on a sheet by printing an image on a sheet using a recording material, for example, a decolorable toner, and further applying a decoloring process to the toner that forms the image by heating. A device having a so-called decoloring device for erasing the image is known. This erasing apparatus includes a reading unit for reading an image to leave an image before erasing, a erasing unit for erasing toner forming an image, and whether erasing processing has been normally performed after erasing. In order to determine whether or not, the above-described reading unit performs image reading again. Thus, when erasing the image formed on the paper, a series of operations are performed in which the content of the paper is read and stored by the reading unit and is erased.

  In recent years, writing instruments have been widely used that make inks colorless by temperature changes caused by heat. Such writing instruments are used in a wide range of applications, from applications such as checking and memos to painting applications. Due to the expansion of applications, the area to be erased when the entry contents become unnecessary increases, and the decoloring work by the dedicated eraser takes time and effort. In order to erase the contents described with this writing instrument, there are an increasing number of cases in which the image is erased by a copying machine which can be erased by heating provided in a convenience store or the like. The ink of a writing instrument that can be colorless is colorless at around 65 degrees. On the other hand, the above-mentioned copying machine normally has a toner fixing temperature of about 180 ° C. Therefore, when blank paper is placed in the paper feed stage and copied on a blank sheet, it is heated at a fixing temperature higher than the decoloring temperature, so it is discharged. The printed paper is erased. Therefore, there has been a problem that memos, pictures or written characters on important documents that are to be retained are erased from the relationship between the above-mentioned ink decolorization temperature and toner fixing temperature.

Japanese Patent No. 5453504

    A problem to be solved by an embodiment of the present invention is to prevent erasure of a sheet that an operator does not want to erase in an image forming apparatus capable of erasing a sheet on which an image is formed with erasable ink or the like. It is an object to provide a possible image forming apparatus.

    Therefore, in order to achieve the above-described problem, the following measures are taken in the embodiment of the present invention. It consists of a heating unit that heats the recording medium and a pressurizing unit, and a fixing process that fixes an image formed of a color erasable material on the recording medium at a fixing temperature or an erasing process that erases an image at the decoloring temperature. A fixing unit to be executed, a reading unit that is arranged upstream of the fixing unit in the conveyance direction of the recording medium, and that reads an identifier indicating whether the color material of the image formed on the recording medium can be decolored, and an identifier by the reading unit And a control unit that controls execution of an erasing process of the image on the recording medium by the fixing device based on the reading result of the image forming apparatus.

1 is a cross-sectional view schematically showing an image forming apparatus in the present embodiment. 1 is a block diagram of an image forming apparatus in the present embodiment. Explanatory drawing of the paper P in this Embodiment. 6 is a flowchart illustrating a process of an erasing job of the image forming apparatus according to the present embodiment. FIG. 3 is an explanatory diagram schematically showing a relationship between a fixing device and a reading unit in the present embodiment. The example of a warning message display in this Embodiment.

    Embodiments of the present invention will be described below with reference to the drawings. In the present embodiment, an MFP (Multi-Function Peripheral) will be described as an example of the image forming apparatus.

    This embodiment will be described with reference to FIGS. FIG. 1 is a cross-sectional view schematically illustrating a configuration example of the MFP 100 according to the embodiment. As illustrated in FIG. 1, the MFP 100 includes a scanner unit 1, a printer unit 2, an operation panel 4, and a system control unit 5.

    In the paper P in the embodiment, as shown in FIG. 3, a check box C is formed at the end of the paper P by toner that is a color material that can be erased by heat. Then, the check box C is filled with a writing instrument that makes the ink colorless by temperature change due to heat. This filled check box C is the identifier M. This identifier M is formed on the paper P when it is not desired to erase the image formed on the paper P. In other words, the identifier M represents whether or not the erasing process can be performed on the image of the paper P on which the image is formed. Note that the position of this check box C is printed in advance outside the printable area of the MFP or at the end of an area that can be printed by an image processing apparatus such as a header or footer defined by document software. I shall keep it. In the embodiment, erasing is an example of erasing processing.

    Returning to FIG. 1, the scanner unit 1 is an apparatus that reads an image of a document and converts it into image data. The scanner unit 1 has a well-known configuration and is configured by, for example, a CCD line sensor that converts an image of a document on a reading surface into image data. The scanner unit 1 may scan a document placed on a platen glass (not shown), or may read an image of a document conveyed by an automatic document feeder (ADF). It may be. The scanner unit 1 is installed on the upper side of the main body of the MFP 100, for example. The scanner unit 1 is controlled by the system control unit 5.

    The printer unit 2 forms an image on a sheet P as a recording medium. In the present embodiment, the printer unit 2 is an electrophotographic image forming unit. The printer unit 2 forms an image using five types of toners (for example, yellow (Y), cyan (C), magenta (M), black (K), and decolored (D)). Yellow (Y), cyan (C), magenta (M), and black (K) toners are non-erasable toners that cannot be erased even when heat of a predetermined fixing temperature or higher is applied. The decolorable toner (D) is a toner that can be decolored by heating at a predetermined temperature exceeding the fixing temperature. The color of the decoloring toner (D) is, for example, dark blue or black. Details of a known configuration for generating an image by the printer unit 2 will be described later.

    The decolorizing toner used in this embodiment is formed by, for example, containing a color material in a binder resin. The erasable color material includes a color developing compound, a developer, and an erasing agent. Examples of the color developing compound include leuco dyes. Examples of the developer include phenols. Examples of the erasing agent include a substance that is compatible with the color developing compound when heated and does not have an affinity for the developer. Colors that can be erased develop color due to the interaction between the color developing compound and the developer, and the interaction between the color developing compound and the developer is interrupted by heating above the color erasing temperature. Is done.

    In the configuration example illustrated in FIG. 1, the printer unit 2 includes a paper feed cassette 20 (20A, 20B, 20C) as a paper feed unit. For example, each of the paper feed cassettes 20A, 20B, and 20C is provided in a detachable state at the bottom of the MFP 100 main body. These paper feed cassettes 20A, 20B, and 20C contain paper P of the type (for example, size and paper quality) set to each. It is also possible to set each size to the corresponding paper feed cassette after storing, for example, paper P of different sizes in these paper feed cassettes 20A, 20B, 20C. Each paper feed cassette 20A, 20B, 20C is provided with a paper feed sensor. The paper feed unit sensor detects the amount of paper contained in the paper feed tray 22. This paper feed unit sensor is, for example, an infrared sensor. In addition, a mechanical sensor such as a known microswitch can be used. This paper feed unit sensor transmits the detection result to the system control unit 5 described later. The printer unit 2 may include a manual feed tray (not shown) as another paper feeding unit.

    Setting information regarding the paper P stored in each of the paper feed cassettes 20A, 20B, and 20C is stored in a nonvolatile memory. The printer unit 2 selects a paper feed cassette that accommodates the paper P used for the printing process according to the setting information. The printer unit 2 prints an image on the paper P fed from the selected paper feed cassette. In the case where the printer unit 2 has a manual feed tray, the size of the paper P set in the manual feed tray input from the operation panel 4 may be stored in the nonvolatile memory described above.

    In the following description, since the paper is transported from the paper supply unit 20 to the paper discharge unit 30, the paper supply unit 20 side is the upstream side with respect to the paper transport direction, and the paper discharge unit 30 side is the paper transport. The downstream side with respect to the direction.

    The transport unit 22 illustrated in FIG. 1 transports the paper P within the printer unit 2. The transport unit 22 transports the paper P supplied from the corresponding paper feed cassette 20A, 20B, or 20C to the registration roller 24 by the pickup rollers 21A, 21B, or 21C. The registration roller 24 conveys the paper P to the transfer position at a timing at which an image is transferred from the intermediate transfer belt 27 described later to the paper P.

    A reading unit 23 is provided in the conveyance unit 22 between the paper supply unit 20 and the intermediate transfer belt 27. Specifically, the reading unit 23 is provided on the upstream side of the sheet P conveyance with respect to the registration roller 24 and on the downstream side of the junction of the reversing paths by the automatic duplex unit (ADU) 31 described later. The reading unit 23 is, for example, a CCD sensor. As shown in FIG. 5, the reading unit 23 is an optical sensor or the like including a light emitting unit 23a and a light receiving unit 23b. In the present embodiment, the reading unit 23 reads the identifier M formed at the end of the paper P.

    Details of image formation will be described below. The image forming unit 25, the exposure unit 26, the intermediate transfer belt 27, and the transfer unit 28 illustrated in FIG. 1 function as a well-known image forming unit that forms an image. The image forming unit 25 forms an image to be transferred to a sheet. In the configuration example of generating the color image shown in FIG. 1, the image forming unit 25Y forms an image corresponding to yellow with yellow toner by color-separating the original image, which will be described in detail later. Similarly, the image forming unit 25M forms an image with magenta toner. The image forming unit 25C forms an image with cyan toner. The image forming unit 25K forms an image with black toner. The image forming units 25Y, 25M, 25C, and 25K superimpose and transfer the toner images of the respective colors on the intermediate transfer belt 27. On the other hand, the image forming unit 25D is an erasable toner that is used when reusing paper and forms an erasable original image. As described above, the color of the decolorable toner is dark blue or black. Accordingly, the image formed by the image forming unit 25D is a monochrome (single color) image. Each of the image forming units 25Y, 25M, 25C, 25K, and 25D has a known configuration, for example, a photosensitive drum, a charging charger, a developing unit including toner, a charge eliminating unit, and the like (only shown in FIG. 1). Note that the image forming unit 25D is used only when reusing paper, but since the configuration and operation are the same as those of other image forming units, the following description will be made simultaneously.

    Although not shown, each of the image forming units 25Y, 25M, 25C, 25K, and 25D has a known sensor such as a potential sensor and a density sensor. The potential sensor is a sensor that detects a surface potential of a well-known photosensitive drum included in each image forming unit. In each of the image forming units 25Y, 25M, 25C, 25K, and 25D, a known charging charger charges the surface of the photosensitive drum before the photosensitive drum is exposed by an exposure unit 26 described later. The system control unit 5 can change the charging condition by the charging charger. The potential sensor detects the surface potential of the photosensitive drum whose surface is charged by the charging charger. The density sensor detects the density of a toner image transferred onto an intermediate transfer belt 27 described later. The density sensor may detect the density of the toner image formed on the photosensitive drum.

    The exposure unit 26 forms an electrostatic latent image of the original image acquired by the scanner unit 1 by laser light on the charged photosensitive drums of the image forming units 25Y, 25M, 25C, 25K, and 25D as described above. . The electrostatic latent image formed on each photosensitive drum is an image developed with toner of each color. That is, the exposure unit 26 irradiates each photosensitive drum with laser light corresponding to each image forming unit controlled according to image data through an optical system such as a polygon mirror. The exposure unit 26 controls the power of the laser beam in accordance with a control signal from the system control unit 5. The exposure unit 26 also controls the modulation amount of the pulse width for controlling the emission of the laser light according to the control signal from the system control unit 5.

    As described above, each of the image forming units 25Y, 25M, 25C, 25K, and 25D develops the electrostatic latent images formed on the respective photosensitive drums with toner of each color by the developing unit. Each of the image forming units 25Y, 25M, 25C, 25K, and 25D forms a toner image as a visible image on the photosensitive drum. The intermediate transfer belt 27 is an intermediate transfer member. When a color image is formed with the above-described non-erasable toner, each of the image forming units 25Y, 25M, 25C, and 25K transfers the toner image formed on the photosensitive drum onto the intermediate transfer belt 27 (1). Next transfer). Specifically, each of the image forming units 25Y, 25M, 25C, and 25K applies a transfer bias to the toner image at the primary transfer position. Each of the image forming units 25Y, 25M, 25C, and 25K controls the transfer bias by the transfer current. The toner image on each photoconductor drum is transferred to the intermediate transfer belt 27 by a transfer bias at each primary transfer position (for example, a portion where the photoconductor drum and the transfer belt are in contact). The system control unit 5 controls the transfer current that each image forming unit uses for the primary transfer process. On the other hand, when the paper is reused, that is, when a monochrome image is formed using a decolorable toner, a toner image as a visible image is formed on the photosensitive drum by the image forming unit 25D. This toner image is transferred to the intermediate transfer belt 27 as described above.

    The transfer unit 28 transfers the toner image on the intermediate transfer belt 27 onto the paper P at the secondary transfer position. The transfer unit 28 includes a support roller 28a and a secondary transfer roller 28b provided along the conveyance path of the paper P. The support roller 28a and the secondary transfer roller 28b are intermediately transferred at the secondary transfer position. This is a position facing the belt 27. The transfer unit 28 applies a transfer bias controlled by a transfer current to the belt 27 at the secondary transfer position. The transfer unit 28 transfers the toner image on the intermediate transfer belt 27 to the paper P by a transfer bias. The system control unit 5 controls a transfer current used for the secondary transfer process.

    The fixing device 29 disposed on the downstream side of the transfer unit 28 has a function of fixing toner onto the paper P. For example, in the embodiment, the fixing device 29 fixes the toner image on the paper P by heat and pressure applied to the paper P.

    In the configuration example shown in FIGS. 1 and 5, the fixing device 29 includes a heat roller (heating unit) 29 b having a built-in heating source 29 a and a pressure roller (pressing unit) 29 c that comes into contact with the pressure mechanism d in a pressurized state. It consists of. The heating source 29a may be a heater whose temperature can be controlled. For example, the heating source 29a may be constituted by a heater lamp such as a halogen lamp, or may be an induction heating (IH) type heater. The heating source 29a may be composed of a plurality of heaters. As shown in FIG. 5, the fixing device 29 further includes a temperature sensor 29e for measuring the temperature of the heat roller 29b. The temperature sensor 29e transmits the temperature of the heat roller 29b to the system controller 5 described later. The pressure mechanism 29d presses the pressure roller 29c to the heat roller 29b. The pressurizing mechanism 29d is configured by an elastic member or the like. When the pressure roller 29c is not pressed against the heat roller 29b by the pressure mechanism 29d, the pressure roller 29c and the heat roller 29b are separated from each other, and a gap is formed between them.

    When performing a fixing process for fixing the toner image on the paper P, the system control unit 5 controls the temperature of the fixing device 29 to be a predetermined fixing temperature. The fixing device 29 heats the sheet P on which the toner image is transferred by the transfer unit 28 at a fixing temperature while applying pressure. As a result, the fixing device 29 fixes the toner image on the paper P. A well-known branching mechanism (not shown) disposed downstream of the fixing device 29 conveys the fixed paper P to either the paper discharge unit 30 or the ADU 31 in response to a user's processing request.

    When erasing an image formed on the paper P, the system control unit 5 performs control so that the temperature of the fixing device 29 becomes a predetermined decoloring temperature. The fixing device 29 heats the paper P to be erased at a decoloring temperature while applying pressure. As a result, the fixing device 29 erases the image formed on the paper P. When the image is erased by the fixing device 29, the paper P is conveyed to the paper discharge unit 30.

    When the paper P fixed or erased by the fixing device 29 is discharged, the paper P is carried out to the paper discharge unit 30. When an image is also formed on the back surface of the paper P fixed by the fixing device 29, the paper P is once transported to the paper discharge unit 30 side, then switched back and transported to the ADU 31. In this case, the ADU 31 again supplies the paper P reversed by the switchback to the upstream side of the registration roller 24 and the reading unit 23.

    In the present embodiment, when the paper P having the identifier M formed in the check box C shown in FIG. 3 is conveyed, the pressure roller 29c is released and the pressure roller 29b is pressed. 29 c is separated, and the paper P is conveyed to the paper discharge unit 30. That is, the erasing process is not executed on the paper P having the identifier M.

    The operation panel 4 is a user interface. The operation panel 4 has various known input buttons and a display unit 4a having a touch panel 4b. The system control unit 5 controls the contents displayed on the display unit 4 a of the operation panel 4. In addition, the operation panel 4 outputs information input by the touch panel 4b or the input button of the display unit 4a to the system control unit 5. Further, at the time of printing, input of information necessary for printing such as the number of printed sheets and density is accepted. Note that the operator operates the operation panel 4 to select one of the two modes of the print mode and the erase mode. The print mode is a mode for forming an image on a sheet set in the sheet feeding unit. The erasing mode is a mode for erasing an image formed on the paper set in the paper feeding unit. That is, the erasing mode does not use the image forming unit 25, the exposure unit 26, the intermediate transfer belt 27, and the transfer unit 28 in the printer unit 2, but uses the paper feeding unit 20, the conveyance unit 22, and the fixing device 29. Erase the image formed in

    Next, the configuration of the control system of MFP 100 will be described. FIG. 2 is a block diagram of MFP 100 according to the present embodiment. Via a system bus 52, a CPU (Central Processing Unit) 51, a ROM (Read Only Memory) 53, a RAM (Random Access Memory) 54, a HDD (Hard Disk Drive) 55, an external I / F (Interface) 56, a printer unit. 2. The operation panel 4 is connected. The CPU 51, ROM 53, and RAM 54 constitute the system control unit 5.

    The ROM 53 stores a program for operating the CPU 51 and a threshold value in advance. For example, it stores a fixing temperature that enables fixing of erasable toner and non-erasable toner. Further, when erasing an image formed on the paper P, a temperature threshold value that is a set temperature (erasing temperature) of the heat roller is also stored in the temperature threshold value storage area of the ROM 53. Further, when the check box C is read by the reading unit 23, the density threshold value is stored in the density threshold value storage area as a threshold value for determining whether or not the check box is filled.

    Various memory areas such as a work area serving as a work area for data processing by a program are dynamically formed in the RAM 54. In addition, a flag area for managing whether or not the identifier M in which the check box C is filled is detected in the reading unit 23 is provided. Specifically, an identifier M management area is provided. The default value of the flag stored in the identifier M management area is “0”. If the reading unit 23 detects the identifier M, the flag “1” is stored. The flag is reset to “0” every time one image is erased. The RAM 54 is provided with a mode identification area. This mode identification area is a flag area for determining the current mode. The flag “1” is stored in the print mode, and the flag “0” is stored in the erase mode. By default, “1” is stored.

    The HDD 55 is installed with an OS (Operating System) that operates the MFP 100. Further, the HDD 55 has a temporary storage area for temporarily storing image information read from the paper P by the scanner unit 1. A warning message to be displayed on the operation panel 4 is also stored in the HDD 55.

The external I / F 56 is an interface for communicating with an external device. For example, the external I / F 56 is an external device such as a client terminal (PC),
The print data corresponding to the print request from is received. The external I / F 56 may be an interface that performs data communication with an external device. For example, the external I / F 56 may be a device (USB memory or the like) locally connected to the external device, or a network for communicating via a network. It may be an interface.

    Since the configuration of the scanner unit 1, the printer unit 2, and the operation panel 4 has been described above, the description thereof is omitted.

    In MFP 100 having the above-described configuration, when the erase mode of paper P is selected from operation panel 4, MFP 100 executes an erase job (erase process) shown in FIG. 4 based on a preset program. .

    When the MFP 100 performs an erasing job, it is assumed that the paper P intended for erasing has already been set in, for example, the paper feeding cassette 20B of the paper feeding unit. It is assumed that an identifier M is formed in advance on a part of the paper P set in the paper feed cassette 20B (paper on which an image is not desired to be erased).

    The system control unit 5 picks up the paper P from the paper feed cassette 20B of the paper feed unit by the pickup roller 21B. Then, the system control unit 5 controls the transport unit 22 to transport the paper P to the registration roller 24 (ACT 101).

    The system control unit 5 reads the check box C printed on the paper P being conveyed to the registration roller 24 by controlling the reading unit 23 (ACT 102). The system control unit 5 compares the information sent from the reading unit 23 with the value stored in the density threshold storage area of the ROM 53 (ACT 103). As shown in FIG. 5A, when the system control unit 5 determines that the check box C is filled and the identifier M is formed (No in ACT 103), the flag stored in the identifier M management area is set to 0. Change from 1 to 1. Then, the system control unit 5 reads out the warning message from the HDD 55 and displays the warning message on the operation panel 4 as shown in FIG. At the same time, the system control unit 5 controls the registration roller 24 to stop the conveyance of the paper P (ACT 104).

    After displaying the warning message, the system control unit 5 refers to the flag of the identifier M management area, and releases the press of the pressurizing mechanism 29d. As a result, the pressure applied by the pressure roller 29c to the heat roller 29b is released. Accordingly, the pressure roller 29c and the heat roller 29b are separated from each other, and a gap is formed between them (ACT 105).

    Subsequently, the system control unit 5 stops the heat generation of the heating source 29a (ACT 106). The system controller 5 compares the value transmitted from the temperature sensor 29e that detects the temperature of the heat roller 29b with the value stored in the temperature threshold storage area of the ROM 53, and the temperature of the heat roller 29b is formed on the paper P. It is determined whether the image has reached a temperature at which it cannot be erased (ACT 107). If the system control unit 5 determines that the temperature of the heat roller 29b is not a temperature at which the image on the paper P cannot be erased (No in ACT 107), the system control unit 5 returns to ACT 107 again. On the other hand, when the system control unit 5 determines that the temperature of the heat roller 29b is a temperature at which the image formed on the paper P cannot be erased (Yes in ACT 107), the registration roller 24 is driven and the paper P is added. The paper passes through the gap between the pressure roller 29 c and the heat roller 29 b and is conveyed to the paper discharge unit 30. At this time, the flag of the identifier M management area is changed from 1 to 0. (ACT108).

    Next, the system control unit 5 refers to the value of the paper feed unit sensor and determines whether or not there is paper P in the paper feed cassette 20B (ACT 114). If it is determined that there is paper P in the paper feed cassette 20B (ACT 114: No), the process returns to ACT 101 and paper P is fed from the paper feed cassette 20B. On the other hand, if it is determined that there is no paper P in the paper feed cassette 20B (ACT 114: YES), the erasing process is terminated.

    In ACT 103, as shown in FIG. 5B, when the system control unit 5 determines that the check box C is not filled and the identifier M is not formed on the paper P (Yes in ACT 103), the identifier M management is performed. The pressure mechanism 29d is pressed with reference to the area flag (ACT 109). As a result, a nip is formed between the pressure roller 29c and the heat roller 29b.

    The system control unit 5 heats the heating source 29a and raises the temperature of the heat roller 29b (ACT 110). Then, the system control unit 5 compares the value transmitted from the temperature sensor 29e with the value stored in the temperature threshold storage area of the ROM 53, and the temperature of the heat roller 29b is the temperature at which the image formed on the paper P can be erased. It is determined whether or not (ACT 111). If the system control unit 5 determines that the temperature of the heat roller 29b is not a temperature at which the image formed on the paper P can be erased (No in ACT 111), the system control unit 5 performs the determination in ACT 111 again. On the other hand, when the system control unit 5 determines that the temperature of the heat roller 29b has reached the temperature at which the image formed on the paper P can be erased (Yes in ACT 111), the system control unit 5 stops heating the heating source 29a, Processing is performed so that the temperature of the heat roller 29b maintains the decoloring temperature (ACT 112).

    Then, the system control unit 5 drives the registration roller 24, passes the paper P through the nip between the pressure roller 29c and the heat roller 29b, and erases the image formed on the paper P (ACT 113). When the paper P passes through the fixing device 29, it is conveyed to the paper discharge unit 30 (ACT 108).

    Similarly to the above, the system control unit 5 refers to the value of the paper feed unit sensor and determines whether there is paper P in the paper feed cassette 20B (ACT 114). If it is determined that there is paper P in the paper feed cassette 20B (ACT 114: No), the process returns to ACT 101 and paper P is fed from the paper feed cassette 20B. On the other hand, if it is determined that there is no paper P in the paper feed cassette 20B (ACT 114: YES), the erasing process is terminated.

    As described above, for example, in an MFP installed in a convenience store, when an operator discolors paper described with a writing instrument that discolors ink by temperature change, there is a mixture of papers that do not want to be erased by mistake. However, it is possible to avoid erasure by forming an identifier indicating whether or not erasure processing is possible in advance in the check box of the paper. In this embodiment, when it is determined that the sheet P is not to be erased, for example, the pressing of the heat roller 29b and the pressure roller 29c is released. As a result, even when the temperature of the heat roller 29b is lower than the decoloring temperature, it is possible to prevent the image formed on the paper P from being erased by the pressing force applied to the paper P.

    As mentioned above, although embodiment of this invention was described, this embodiment is shown as an example and is not intending limiting the range of invention. The novel embodiment can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. This embodiment and its modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

5 System Control Unit 23 Reading Unit 29 Fixing Unit 54 RAM
55 HDD
100 MFP

Therefore, in order to achieve the above-described problem, the following measures are taken in the embodiment of the present invention. A conveying unit that conveys the recording medium, a heating unit for executing the erasing processing for decoloring the image by heating the recording medium on which the image is formed by color erasable color material at a color erasing temperature, the heating separable therefrom a pressurizing relative parts, and the heating part detector for detecting a temperature of said determined whether to execute the decoloring processing, when it is determined not to execute the erasing processing the heat generation of the heating unit is stopped, it determines that the heating unit based on a detection result of the detecting portion is Tsu name below the decoloring temperature stops the conveyance of the recording medium by controlling the transport unit a control unit for the recording medium body that controls the transport unit to be conveyed, an image processing apparatus having a.

Claims (5)

It consists of a heating unit that heats the recording medium and a pressurizing unit, and a fixing process that fixes an image formed of a color erasable material on the recording medium at a fixing temperature or an erasing process that erases an image at the decoloring temperature. A fuser to perform,
A reading unit that is arranged upstream of the fixing device in the conveyance direction of the recording medium and reads an identifier indicating whether or not the color material of the image formed on the recording medium can be decolored;
A control unit that controls execution of an erasing process of an image on the recording medium by the fixing device, based on a reading result of the identifier by the reading unit;
An image forming apparatus. The pressure unit of the fixing unit is configured to be able to contact and separate from the heating unit of the fixing unit, and the control unit does not execute an erasing process based on the reading result of the identifier of the recording medium by the reading unit. 2. The image forming apparatus according to claim 1, wherein after the pressurizing unit is separated from the heating unit and released from being pressed, the recording medium is controlled to be conveyed between the pressurizing unit and the heating unit.   The control unit, when executing the erasing process based on the reading result of the identifier of the recording medium by the reading unit, presses the pressure unit to the heating unit and raises the heating unit to a predetermined decoloring temperature. The image forming apparatus according to claim 2, wherein the recording medium is controlled to be conveyed between the heating unit and the pressurizing unit and erase an image after the recording medium is pressed.   4. The control unit according to claim 1, wherein the controller controls to stop the heating of the heating unit when the color erasing process is not performed based on a reading result of the identifier of the recording medium by the reading unit. The image forming apparatus described in 1. A display unit;
4. The control unit according to claim 3, wherein when the erasing process is not performed based on a result of reading the identifier of the recording medium by the reading unit, the control unit performs control to stop conveyance of the recording medium and display a warning on the display unit. The image forming apparatus described.

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