CN106200323A - Image forming device and decolorization processing method thereof - Google Patents

Abstract

The invention provides an image forming apparatus and an erasing method thereof, which can erase a handwritten image with a low erasing temperature with a small energy consumption while maintaining an original image. The image forming apparatus includes: a printing function of performing image formation by heating and fixing an unfixed toner image transferred to a sheet at a fixing temperature by a heating section; and a decoloring function of heating, by the heating unit, an image formed on a decoloring target sheet with a decoloring coloring material to decolor the image, the image forming apparatus including: a temperature sensor that detects a temperature of the heating portion; and a control section having a normal decoloring mode in which, in order to execute the decoloring function, the control section controls a temperature of the heating section to be lower than a first temperature higher than the fixing temperature and to be equal to or higher than a second temperature lower than the fixing temperature, based on temperature detection information of the temperature sensor.

Description

Image forming device and decolorization processing method thereof

technical field

The present invention relates to a technique for decolorizing a second image recorded on the same sheet by handwriting or the like using a decolorizable color material without decolorizing a first image printed on a sheet with a decolorizable color material.

Background technique

In the prior art, as a method of decolorizing an image printed with a decolorizable color material on a sheet, there is generally the following method: for example, in the case of using a decolorizable toner, heating the decolorizable toner image Decolorization is carried out at a temperature above the decolorization temperature of the toner.

The erasable toner has an erasing temperature higher than a fixing temperature at which the erasable toner is fixed. Therefore, the decolorization temperature in the decolorization process is also set according to the decolorization temperature of the toner.

There has been proposed an image forming apparatus that forms an image on the same sheet using a plurality of decolorable color materials having different decolorization start temperatures.

For example, when an image is recorded by a pen filled with erasable ink or the like used by a user, the erasing temperature of the ink is lower than that of an erasable toner used in an electrophotographic image forming apparatus.

In addition, in the case of performing decolorization treatment using a decolorization device corresponding to the decolorization temperature of the decolorization toner, the image printed with the decolorization toner and the image printed with the decolorization pen after that are decolorized at a high temperature decolorization temperature of the decolorization toner. Added images are heated together. Therefore, it is not possible to decolorize only the pen-written image while leaving the image printed with the decolorizing toner as the original image.

On the other hand, in the case of decolorizing an original on which a handwritten image has been added with a decolorizing pen on a sheet on which an original image has been formed with a non-decolorizing toner by a decolorizing device, the decolorizing toner is decolorized. Colored high-temperature heat heats the image recorded with the eraser pen. Therefore, even though the color can be fully decolorized by heating at a low-temperature decolorization temperature, high-temperature heating is still performed, resulting in unnecessary waste of energy.

Contents of the invention

The technical problem to be solved by the invention

An object of the present invention is to provide a technique for decolorizing a handwritten image with a low decolorization temperature with less energy consumption while maintaining the original image.

Solutions for technical problems

An image forming apparatus according to an aspect of the present invention includes: a printing function for performing image formation by heating and fixing an unfixed toner image transferred to a sheet at a fixing temperature by a heating unit; and a decolorizing function for performing image formation by using the heating unit. The image formed on the sheet to be decolorized using a decolorizable coloring material is heated to decolorize the image, and the image forming apparatus includes: a temperature sensor for detecting the temperature of the heating unit; and a control unit having In the normal decolorization mode, in order to perform the decolorization function, the control part controls the temperature of the heating part to be lower than the temperature of the heating part based on the temperature detection information of the temperature sensor Between a first temperature higher than the fixing temperature and a second temperature lower than the fixing temperature or more.

An image forming apparatus according to another aspect of the present invention includes: a printing function for performing image formation by heating and fixing an unfixed toner image transferred to a sheet at a fixing temperature by a heating unit; and a decolorizing function for using the heating unit to form an image. The image formed on the sheet to be decolorized using a decolorizable coloring material is heated to decolorize the image, and the image forming apparatus includes: a control unit having a residual heat decolorization mode for decolorizing the image by the residual heat In the mode, in order to execute the decolorizing function, the control unit passes the sheet to be decolorized through the heating unit during a standby mode of the printing function.

An image forming apparatus according to still another aspect of the present invention includes: a printing function for performing image formation by heating and fixing an unfixed toner image transferred to a sheet at a fixing temperature by a heating unit; and a decolorizing function for using the heating unit to form an image. The image formed on the sheet to be decolorized is heated with a decolorizable coloring material to decolorize the image, and the image forming apparatus includes: a temperature sensor for detecting the temperature of the heating unit; and a control unit, It has a normal decolorization mode and a residual heat decolorization mode. In the normal decolorization mode, in order to perform the decolorization function, the control part controls the temperature of the heating part based on the temperature detection information of the temperature sensor. Between below a first temperature higher than the fixing temperature and above a second temperature lower than the fixing temperature, in the residual heat erasing mode, in order to perform the erasing function, the control unit In the standby mode of the printing function, the sheet to be decolorized is passed through the heating unit.

A decolorization processing method of an image forming apparatus according to still another aspect of the present invention includes: detecting the standby mode of the printing function, detecting the start of the decolorization processing function, setting the number of processing target sheets of the decolorization processing target sheets, and making the decolorization process The sheet to be processed passes through the heating unit, the number of the sheets to be decolorized which pass through the heating unit is counted, and the sheet to be decolorized is passed through the heating unit until the counted number reaches a set value. Describe the number of sheets to be processed.

Description of drawings

FIG. 1 is a schematic diagram of an image forming apparatus according to an embodiment.

FIG. 2 is a control block diagram of the image forming apparatus of FIG. 1 .

FIG. 3 is a diagram illustrating an image on a sheet subjected to decolorization processing.

FIG. 4 is a flowchart showing a decolorization process flow of decolorizing only the second image in the normal decolorization mode.

FIG. 5 is a flowchart showing the flow of decolorization processing in the residual heat constant decolorization mode.

detailed description

Hereinafter, an image forming apparatus according to an embodiment will be described based on the drawings.

1 is a schematic diagram of an image forming apparatus according to an embodiment, FIG. 2 is a control block diagram of the image forming apparatus of FIG. 1 , and FIG. 3 is an explanatory diagram of an image on a sheet subjected to decolorization processing.

The image forming apparatus 10 of this embodiment is an electrophotographic image forming apparatus that forms an image using toner, and has a first image that can be printed with a decolorizable color material and a second image that can be handwritten with a decolorizable ink or the like. Decolorization mode for image decolorization. In addition, the toner used for image formation may be decolorizable toner or non-decolorizable toner. In addition, although the example of monochrome printing was given, full-color printing is also possible.

Here, the erasable color material (erasable color material), such as erasable toner and erasable ink, includes a color-forming compound, a color developer, and a color erasing agent. The color-forming compound may, for example, be a leuco dye. The color developer may, for example, be phenols. Examples of the decolorizer include those that are compatible with the color-forming compound when heated and have no affinity with the color-developing agent. The decolorizable color material develops color due to the interaction between the color-forming compound and the color-developing agent. With heating above the color-extinction temperature, the interaction between the color-forming compound and the color-developing agent is terminated, thereby decolorizing. The thermally erasable color material used in this embodiment is composed of at least a color-forming compound, a color developer, and a color decolorizer. In addition, the decolorization temperature differs depending on the material and the like of the decolorizable (permanent) coloring material.

As shown in FIG. 3 , on the sheet S are displayed a first image 100 printed with a first decolorizable color material in an image forming apparatus, and a handwritten image 100 recorded with a pen filled with ink of a second decolorizable color material. The second image 200 . The decolorization temperature T1 of the first achromatic color material of the first image 100 is higher than the decolorization temperature T2 of the second achromatic color material of the second image 200 . The second decolorization temperature T2 is set to 60° C. or higher. The sheet S shown in FIG. 3 is, for example, a questionnaire paper, so the survey items (Q1., Q2....) and the answer items (A1. whether...) are the first image 100, enclosing yes and no handwritten images and comments The handwritten item of the column is the second image 200 .

Such questionnaire paper can be used multiple times by using the first image 100 such as survey items as the original image, and only the second image is decolorized after collecting the questionnaire paper. In addition, the sheet S can be reused by also decolorizing the first image 100 which is the original image. It should be noted that the image shown in FIG. 3 is only an example for simplifying the description, and it is needless to say that erasing a normal printed original image with a pen filled with erasing ink is also included in the present invention.

In FIG. 1 , an image forming apparatus 10 includes a developer 12 , a laser exposure unit 14 , a cleaning unit 15 , a transfer unit 16 and the like arranged around a photosensitive drum 11 serving as an image carrier. For example, an electrostatic latent image is formed on the photosensitive drum 11 by image light from the laser exposure unit 14 based on document information from a computer (not shown), and the electrostatic latent image is developed with toner in the developing device 12 to form a toner. Adjust the image. The control unit 30 controls the entire image forming apparatus 10 , and displays, for example, various modes on the display unit 25 through the operation of the operation unit 24 . When a selection section such as various modes displayed on the display section 25 is selected, the control section 30 acquires a signal of the selected item.

In addition, the image forming apparatus 10 has an upper paper feeding cassette 17 and a lower paper feeding cassette 18 . White paper sheets are stored in a loaded state in the upper sheet feeding cassette 17 , and sheets S to be decolorized, for example, as shown in FIG. 3 are stored in the lower sheet feeding cassette 18 . The sheet S to be decolorized as shown in FIG. 3 can also be placed on the manual tray 27 .

In the printing mode, the white paper sheets of the upper paper feed cassette 17 are conveyed one by one to the conveyance unit 19 by a paper feed unit (not shown) such as a paper feed roller, and are temporarily stopped by the registration roller 20 at a predetermined position. It is transported to the transfer position 21 at regular intervals. At the transfer position 21 , the toner image on the photosensitive drum 11 is transferred onto a white paper sheet by the transfer unit 16 . Furthermore, the white paper sheet is conveyed to the heating unit 22 at a fixing temperature, and the unfixed toner image is fixed on the white paper sheet by heating and pressing, and is discharged to the paper discharge unit 13 by the discharge roller 23 . The temperature of the heating unit 22 is detected by a temperature sensor 26 . In addition, the heat storage body 29 may be arrange|positioned in the vicinity of the heating part 22, for example, a heating roller, and the heat which the heating part 22 generate|occur|produces may be accumulated.

On the other hand, in the decolorization mode, the sheets S to be decolorized in the lower paper feed cassette 18 or the manual tray 27 are conveyed one by one to the conveyance unit 19 by a paper feed unit (not shown) such as a paper feed roller. Furthermore, it is sent to the heating part 22 whose temperature is controlled at the decolorization temperature. It is to be noted that the formation of toner images is not performed in the erasing mode.

The heating unit 22 is controlled by the control unit 30 at a fixing temperature T3 for heating to fix an unfixed toner image of decolorable or non-decolorable toner, and a heating temperature for decolorizing the decolorizable toner (No. a decolorization temperature) T1, and a heating temperature (second decolorization temperature) T2 for decolorizing the image of the decolorization ink. Here, the first decolorization temperature T1 is the highest, the next is the fixing temperature T3, and the lowest is the second decolorization temperature T2. That is, these temperatures have a relationship of T2<T3<T1.

In the image forming apparatus 10, the control section 30 maintains the heating section 22 at the standby temperature in the standby mode in which the image forming process is not performed. That is, the standby temperature is equal to or lower than T3.

In addition, in the standby mode, regarding the energization of the heater (not shown) of the heating unit 22 , when the standby mode time exceeds a predetermined time, the energization of the heating unit is stopped. The standby temperature in the standby mode is lower than the fixing temperature T3, but is a temperature at which the control unit 30 can immediately raise the temperature to the fixing temperature T3 when the print signal is received, and is higher than the second decolorizing temperature T2. In addition, even if the power supply to the heating unit 22 is stopped in the standby temperature state, the temperature of the heating unit 22 after a certain period of time has elapsed since the power supply is stopped is lower than the decolorization temperature of the second image 200 handwritten with a decolorizing pen (for example, about 60°C) is high enough. In addition, in the image forming apparatus 10 , the high temperature of the heating unit 22 is thermally transmitted to the casing of the heating unit 22 , surrounding frame members, and the like. Furthermore, there are heat sources such as a driving motor of the image forming apparatus 10 , a power supply unit, and the like.

Therefore, due to the heat from such a heat source, the temperature of the heating unit 22 can be maintained at or above the decolorization temperature of the second image 200 for a long period of time even in a state where energization is stopped.

Therefore, in such a temperature state, even if the sheet S to be decolorized passes through the heating unit in a state where energization is stopped, decolorization of the second image 200 of the sheet S can be performed on a certain number of sheets. It should be noted that by accumulating the residual heat of the heating unit 22 in the thermal accumulator 29 and transferring the heat of the thermal accumulator 29 to the heating unit 22 in a state where the energization is stopped, the second image of the sheet S can be further realized. Decolorization treatment (hereinafter referred to as residual heat decolorization mode).

FIG. 2 shows a control block diagram of the image forming apparatus of FIG. 1 . In addition, the mode which performs decolorization process by controlling the temperature of the heating part 22 is called normal decolorization mode.

In the image forming apparatus 10, the control unit 30, the temperature sensor 26, the display unit 25, the operation unit 24, the paper feeding units of the paper feeding cassettes 17 and 18, the heating unit 22, the manual tray 27, the sheet conveying number counter 28, etc. are connected to the bus. 50 connections.

A printing/color erasing switching display section 250 for switching between the printing mode and the erasing mode is displayed on the display section 25 . As the display unit 250 is pressed, the processor 31 of the control unit 30 alternately receives selection signals for the print mode and the decolorization mode. A normal/waste heat mode switching display portion 251 is displayed on the display portion 25 . As the display portion 251 is pressed, the processor 31 of the control portion 30 alternately receives selection signals of the normal decolorization mode and the residual heat decolorization mode.

The display unit 25 displays a number setting display unit 252 for setting the number (X) of decolorization-processing sheets S to be decolorized. In this embodiment, the number of decolorizing sheets (X) is displayed as a predetermined number N or more (or less), and as the display unit 252 is pressed, the processor 31 of the control unit 30 alternately receives N or more and Selection signal for N sheets or less.

In the residual heat decolorization mode, the number of sheets that can be decolorized by residual heat is limited to a certain extent, and the number of sheets that can be decolorized by residual heat is set as a threshold value N (predetermined number of sheets). Therefore, in the residual heat decolorization mode, differential processing is performed according to whether or not the set number of decolorization processing sheets (X) exceeds the threshold N.

When the control unit 30 receives the selection signal for N or more sheets, it executes the processing in the processing sheet number setting mode to perform decolorization processing for N or more sheets. At this time, if the temperature (T) of the heating unit 22 falls below the second processing temperature (T2) (T<T2), the second image 200 cannot be decolorized. Although the decolorization process can be stopped in the middle of the residual heat decolorization mode, it is necessary to perform the decolorization process on the remaining sheets S to be decolorized. Therefore, in the standby mode, a restart mode may be provided in which the decolorization process is restarted when the temperature T of the heating unit 22 becomes the condition of the second process temperature T2 or higher (T≧T2). In addition, it is also possible to set a normal decolorization mode restoration mode in which subsequent decolorization processing is performed in the normal decolorization mode. It should be noted that if the decolorization process is not urgently needed, the decolorization process in the above restart mode can be performed.

It should be noted that, when performing the decolorization process on the decolorization target sheet S stored in the sheet feeding cassette in the residual heat decolorization mode, the number of sheets to be processed (X) may not be set, and sheets not shown in the figure may be used. The detection sensor detects whether or not the sheet S to be decolorized is stored in the sheet feeding cassette. Therefore, the decolorization process may be performed when the sheet S to be decolorized is stored in the sheet feeding cassette, and the decolorization process may not be performed when no sheet S to be decolorized is stored.

On the other hand, when the sheet S to be decolorized is placed on the manual tray 27, it is desirable to immediately execute the decolorized process. In this case, it is also possible to implement the waste heat decolorization mode, and when the temperature (T) of the heating part 22 drops below the second processing temperature (T2) (T<T2), the normal decolorization mode recovery mode is restored to In the normal decolorization mode, the decolorization process is performed on the remaining sheets S to be decolorized.

In addition, in the case of N sheets or less, the decolorization process is performed until the heating unit 22 changes from the standby temperature to less than the second decolorization temperature T2. It should be noted that when the temperature of the heating unit 22 is changed from the standby temperature to less than the second decolorization temperature T2, the decolorization process ends when all the processed sheets are decolorized.

Temperature setting display portions 253 and 254 for setting the first decolorization temperature T1 and the second decolorization temperature T2 are displayed on the display portion 25 . When the temperature setting display portion 253 of the first decolorizing temperature T1 is pressed, the types of the decolorizing toner etc. are displayed, and if a suitable decolorizing toner etc. is selected among the displayed items (if there is no matching In the case of the toner, when the first decolorization temperature T1) is manually set by the operation unit 24, the processor 31 of the control unit 30 receives the first decolorization temperature information. In addition, when the temperature setting display part 254 of the second decolorization temperature T2 is pressed, the name of the pen filled with the decolorization ink, etc. are displayed. In the case of a pen, when the second decolorization temperature T2) is manually set by using the operation part 24, the processor 31 of the control part 30 receives the second decolorization temperature information.

The control unit (controller) 30 has a processor 31 constituted by a CPU (Central Processing Unit: Central Processing Unit) or an MPU (Micro Processing Unit: Microprocessor), and a memory 32 .

The memory 32 is, for example, a semiconductor memory, and includes a ROM (Read Only Memory) 33 storing various control programs, and a RAM (Random Access Memory) 34 providing a temporary operation area for the processor 31 .

The control unit 30 performs a printing operation upon receiving a printing mode selection signal. The control unit 30 executes the operation of the decolorization mode when receiving the selection signal of the decolorization mode. At this time, a selection signal of the normal decolorization mode or the residual heat decolorization mode is received.

The control unit 30 controls the energization of the heater of the heating unit 22 based on the detected temperature information of the temperature sensor 26 of the heating unit 2 , and the like. It should be noted that what is displayed on the display unit 25 in the decolorization mode is a display example when only the second image 200 is decolorized.

Next, the flow of decolorizing only the second image 200 in the normal decolorizing mode will be described based on the flowchart shown in FIG. 4 . It should be noted that the case where the sheet S to be decolorized is placed on the manual tray 27 is taken as an example.

In Act1, it is determined whether it is the normal decolorization mode, if it is the normal decolorization mode (Yes), then proceed to Act2, if it is the residual heat decolorization mode (No), then proceed to the residual heat decolorization mode in FIG. 5 .

In Act2, the first decolorization temperature T1 and the second decolorization temperature T2 are set, and the process proceeds to Act3.

In Act3, it waits for the start button of the decolorization process to be pressed to receive the start of the decolorization process, and proceeds to Act4.

In Act4, it is determined whether the detected temperature T of the temperature sensor 26 is lower than the second decolorization temperature T (T<T2). That is, if it is above the second temperature T2 at which the second image 200 can be decolorized, the process proceeds to Act6, and if the second temperature T2 at which the second image 200 can be decolorized is not reached, the process proceeds to Act5.

In Act5, the heater of the heating unit 22 is energized (heater ON), and the process proceeds to Act6.

In Act6, it is determined whether the temperature T detected by the temperature sensor 26 is equal to or higher than the first decolorization temperature T1 (Yes) or is lower than the first decolorization temperature (No). That is, if the temperature of the heating unit 22 exceeds the first decolorization temperature T1 for decolorizing the first image 100 , in Act8 , the energization of the heater of the heating unit 22 is stopped (the heater is turned off), and the process returns to Act4 . In addition, if the temperature of the heating unit 22 has not reached the first decolorization temperature T1 for decolorizing the first image 100 , the process proceeds to Act 7 .

In Act7, conveyance of the sheet S to be decolorized is started on the manual tray 27, and the process proceeds to Act9.

In Act9, it is determined whether the temperature T detected by the temperature sensor 26 is equal to or higher than the second decolorization temperature T2. That is, if the temperature of the heating part 22 reaches the second decolorization temperature T2 that can decolorize the second image 200, then proceed to Act10, if the temperature of the heating part 22 does not reach the second temperature that can decolorize the second image 200 T2, proceed to Act11.

In Act10, if the temperature T of the heating part 22 is equal to or higher than the first decolorization temperature, the process proceeds to Act12, and if the temperature T of the heating part 22 is lower than the first decolorization temperature T1, the process proceeds to Act13.

In Act11, the heater of the heating unit 22 is energized (heater ON), the temperature of the heating unit 22 is raised to a temperature at which the second image 200 can be decolorized, and the process proceeds to Act10.

In Act12, the energization to the heater of the heating part 22 is stopped (heater OFF), and it progresses to Act13.

Act4～Act12 carry out temperature control to the heater of heating part 22, make the temperature T of heating part 22 maintain at the first decolorization temperature T1 that can decolorize the first image 100, but can decolorize the second image 200. The decolorization process of the sheet S to be decolorized is performed at the second decolorization temperature T2 or higher, that is, the relationship of T2≦T<T1 is maintained.

In Act 13, when the decolorization processing of the decolorization target sheet S is completed, the decolorization-processed sheet is ejected, and the process proceeds to Act 14.

In Act14, it is judged whether there is a next decolorization processing target sheet S, and if not, this processing ends, and if yes, returns to Act3, and waits for the start of decolorization processing.

In the normal decolorization mode of this embodiment, temperature control of the heating unit 22 is performed to maintain the second decolorization temperature T2 lower than the fixing temperature. Therefore, only the second image 200 recorded with a pen filled with erasing ink or the like can be decolorized with low power consumption, and only the first image used as the original image can be restored. Furthermore, such a function can be easily incorporated into an image forming apparatus such as a general MFP.

According to the present embodiment, when erasing the portion that is erased by the user with erasable ink or the like, the temperature of the heating portion is set to be equal to or less than the fixing temperature of the toner and equal to the second erasable temperature T2 of the erasable color. In this method, the sheet S to be decolorized is heated, and the portion of the sheet S to be erased by the user with erasable ink or the like is passed through the heating unit 22 in the same manner as a normal printing operation.

At this time, since it is not necessary to print on the sheet S to be decolorized, it is only necessary to perform heating of the heating unit 22 and conveyance of the sheet S as minimum operations. Regarding the second decolorization temperature T2 set to the heating part 22, the user can set multiple temperature ranges according to the characteristics of the decolorization temperature of the decolorization ink used, etc. The setting that matches the color ink, so that the writing of the specific decolorizable ink that needs to be decolorized can be decolorized.

In addition, by using the existing heating part (fixing part) of the toner and changing the temperature setting of the fixing part during decolorization, it is relatively easy to use only the user's later erasable ink and the like with less power consumption. The image data can be decolorized and can be restored to the original original before deletion.

Next, based on the flowchart shown in FIG. 5 , the flow of the decolorization process performed on only the second image 200 in the residual heat decolorization mode will be described. It should be noted that the case where the sheet S to be decolorized is set in the sheet feeding cassette 18 is taken as an example. The number of sheets S that can be stored in the sheet feeding cassette 18 is greater than the number of sheets S that can be loaded on the manual tray 27 . Therefore, in the case of the processing sheet number setting mode in which the number of sheets to be decolorized (X) is set in the residual heat decolorization mode, a plurality of sheets can be set. In addition, for example, when specifying the paper feeding cassette 18 to set the color erasing mode, the processing sheet number setting mode may be automatically selected. In this case, it is possible to effectively use unconsumed thermal energy in the standby mode in which no printing operation is performed.

In Act21, it is judged whether it is the residual heat erasing mode, and if it is the residual heat erasing mode (Yes), proceed to Act22, and if it is the normal erasing mode (No), proceed to the normal erasing mode in FIG. 4 .

In Act22, the second decolorization temperature T2 is set, and the process proceeds to Act23.

In Act23, the wait is shifted to the standby mode, and the process proceeds to Act24.

In Act24, it waits for the acquisition of a signal notifying the start of the decolorization process, and proceeds to Act25.

In Act25, if the number of sheets to be processed (X) is selected to be more than the set number of sheets (N) in the number of sheets setting display part 252 and the signal of the number of sheets to be processed is received, proceed to Act26 , when the number of sheets to be processed (X) is less than the set number of sheets (N), proceed to Act27.

In Act26, the number of sheets to be processed (X) is set, and decolorization processing is performed, and the process proceeds to Act28.

In Act27, the decolorization process is performed in the standby mode, and the decolorization process is performed until the temperature T of the heating part 22 becomes less than the second decolorization temperature T2. When the temperature T of the heating part 22 becomes less than the second decolorization temperature T2 , proceed to Act30.

In Act28, based on the temperature detection information of the temperature sensor 26, before reaching the number of sheets to be processed (X), when the temperature T of the heating part 22 drops below the second decolorization temperature T2, proceed to Act30, and the temperature T of the heating part 22 If it is equal to or higher than the second decolorization temperature T2, proceed to Act29.

In Act29, it waits until the counted number (n) of the number of conveyed sheets counter 28 reaches the number of processed sheets, and this process ends.

In Act30, in the standby mode, the process waits for the temperature T of the heating unit 22 to become equal to or higher than the second decolorization temperature T2, and proceeds to Act29 to perform decolorization processing on the remaining sheets S to be decolorized.

In the residual heat decolorization mode shown in FIG. 5 , the heater of the heating unit 22 is not energized for decolorizing the second image, so that power can be saved and residual heat of the image forming apparatus can be effectively used.

It should be noted that the image forming apparatus of the present invention may have any one of the normal decolorization mode and the residual heat decolorization mode, or both of the normal decolorization mode and the residual heat decolorization mode.

This embodiment can be implemented in other various forms in the range which does not deviate from the spirit or main characteristic. Therefore, all points of the above-mentioned embodiment are merely illustrations and should not be construed as limited. The scope of the present invention is indicated by the claims and is not limited in any way by the text of the description. In addition, all modifications, various improvements, substitutions, and rearrangements belonging to the equivalent scope of the claims are included in the scope of the present invention.

Explanation of reference signs

10 image forming device; 17, 18 paper feeding cassette; 22 heating part; 26 temperature sensor;

27 manual pallets; 30 control units.

Claims (10)

1. An image forming device, characterized in that: a printing function for performing image formation by heat-fixing an unfixed toner image transferred to a sheet at a fixing temperature by a heating portion; and a decolorization function for decolorizing an image formed on a decolorization processing target sheet using a decolorization coloring material by the heating unit, The image forming apparatus has: a temperature sensor that detects the temperature of the heating portion; and The control part has a normal decolorization mode. In the normal decolorization mode, in order to perform the decolorization function, the control part controls the temperature of the heating part to a low temperature based on the temperature detection information of the temperature sensor. Between a first temperature higher than the fusing temperature and a second temperature lower than the fusing temperature or more. 2. An image forming device, characterized in that: a printing function for performing image formation by heat-fixing an unfixed toner image transferred to a sheet at a fixing temperature by a heating portion; and a decolorization function for decolorizing an image formed on a decolorization processing target sheet using a decolorization coloring material by the heating unit, The image forming apparatus has: The control unit has a residual heat decolorization mode, in which the control unit passes the decolorization target sheet through the the heating section. 3. The image forming apparatus according to claim 2, wherein: The image forming apparatus further includes a heat accumulator for accumulating waste heat of the heating unit. 4. The image forming apparatus according to claim 2, wherein: In the residual heat erasing mode, residual heat in the image forming apparatus is supplied to the heating unit. 5. The image forming apparatus according to claim 4, wherein: The heat source of the waste heat includes a driving motor and a power supply unit in the image forming apparatus. 6. The image forming apparatus according to claim 2, wherein: In the residual heat decolorization mode, the number of sheets to be decolorized is set, and the set number of sheets to be decolorized passes through the heating unit. 7. An image forming device, comprising: a printing function for performing image formation by heat-fixing an unfixed toner image transferred to a sheet at a fixing temperature by a heating portion; and a decolorization function for decolorizing an image formed on a decolorization processing target sheet using a decolorization coloring material by the heating unit, The image forming apparatus has: a temperature sensor that detects the temperature of the heating portion; and The control unit has a normal decolorization mode and a waste heat decolorization mode. In the normal decolorization mode, in order to perform the decolorization function, the control unit turns the heating unit to The temperature is controlled between a first temperature lower than the fixing temperature and a second temperature lower than the fixing temperature, and in the residual heat erasing mode, in order to perform the erasing function, the The control unit passes the sheet to be decolorized through the heating unit during a standby mode of the printing function. 8. The image forming apparatus according to claim 7, wherein: It is possible to switch from the residual heat decolorization mode to the normal decolorization mode. 9. The image forming apparatus according to any one of claims 1 to 8, wherein: A decolorable coloring material that is decolorized by heating at a temperature higher than the first decolorization temperature higher than the fixing temperature is printed on the decolorization-processing target sheet that is subjected to the decolorization function. An image, and a second image is recorded on a decolorable color material that is decolorized by heating at a temperature higher than the second decolorization temperature lower than the fixing temperature. 10. A decolorization processing method for an image forming device, comprising: detect the standby mode of the printing function, detects the start of the decolorization processing function, Set the number of processing target sheets of decolorization processing target sheets, passing the sheet to be decolorized through a heating section, counting the number of sheets to be decolorized that have passed through the heating unit, The sheet to be decolorized is passed through the heating unit until the number of counted sheets reaches the set number of sheets to be processed.