Decoloring system and control method of decoloring system

A decoloring system has a scanner that reads an image on a paper sheet and generates image data; a first roller that applies heat on the paper sheet to decolor the image on the paper sheet; a heater that heats the roller; a first transporting mechanism that transports the paper sheet having the image to the scanner; a second transporting mechanism that transports the paper sheet via the first transporting mechanism to the heater; an operation panel that receives a read condition of the image as input by a user; and a controller that determines an operating condition of the heater, and a transporting speed of the paper sheet by the first transporting mechanism and the second transporting mechanism on the basis of the image read condition input by the user through the operation panel.

FIELD

Embodiments described herein relate generally to a decoloring system for erasing a color of an image formed on each paper sheet and a control method of a decoloring system.

BACKGROUND

There have been developed recording or printing materials in which an image formed by the material may be erased by applying heat over a prescribed temperature to an image formed of the recording material. When such recording material is used to print on a sheet of paper, by applying heat on the image printed on the paper sheet, the paper sheet can be reused. However, in order to reuse the paper sheet, the color of the image should be erased to a state over a prescribed level of thoroughness, i.e., to a level at which the erased image is not readily apparent to the naked eye, and the paper sheet should not be damaged. In recent years, there has been developed a decoloring system with the function of erasing the color (including black and when on a colored paper sheet, white) formed on the paper sheet and the function of determination of whether the paper sheet can be reused.

DETAILED DESCRIPTION

Hereinafter, further embodiments will be described with reference to the drawings. In the drawings, the same reference numerals denote the same or similar portions respectively.

In the following, a first embodiment will be explained with reference toFIGS. 1 to 11.FIG. 1is a diagram illustrating a configuration of a decoloring system1of the first embodiment. Here, the decoloring system1uses a decolorable toner or decolorable ink or other “decolorable coloring material” to carry out “decoloring process” for a paper sheet (recording media) having an image formed on its surface. Here, the decoloring process is defined as a process for erasing the color of the image by the decolorable coloring material. The decolorable coloring material refers to a coloring agent, developing agent, or decoloring agent. An example of the coloring agent is a leuco dye. An example of the developing agent is one or more phenol. The decoloring agent is a substance that has mutual dissolving ability with the developing agent and has affinity to the coloring agent when heated. The decolorable coloring material is colored due to the interaction between the coloring agent and the developing agent. When heated to over the decoloring temperature, the interaction between the coloring agent and the developing agent deactivates, so that discoloration, or erasing, takes place. In the following, the decolorable coloring material will be referred to as recording material.

The decoloring system1contains a paper feeding tray2, paper discharge trays3,4, scanners5,6, a decoloring unit7, a printer8, a paper transporting mechanism, and an operation panel9. The paper transporting mechanism contains plural rollers, sensors and transporting passages. The transporting passage from a roller11to a merging point50is defined as a first transporting passage; the transporting passage from the merging point50to a gate51is defined as a second transporting passage; the transporting passage from the gate51, via the decoloring unit7, and returning to the merging point50is defined as a third transporting passage; the transporting passage from the gate51via a gate53to the paper discharge tray3is defined as a fourth transporting passage; and the transporting passage from the gate53to the paper discharge tray4is defined as a fifth transporting passage.

According to the first embodiment, pairs of rollers are provided on the transporting passages. Although not a necessity, one roller of a pair is a driving roller connected to a motor either directly or indirectly, while the other roller of a pair is a slave roller that is rotated following/by the diving roller or by the action of a sheet passing therethrough being driven by a driving roller. In the drawing, the diving roller is indicated by a double circle, i.e., a circle within a circle.

The paper feeding tray2accommodates the paper sheets to be processed for reuse. Here, the process for reuse is defined as a series of processing steps including the following functions: the function of acquisition of the image data of the paper sheet before the decoloring process, the function of decoloring the sheet, and the function of checking the state of, or completeness of, decoloration of the paper sheet. The paper feeding tray2has a sensor30, a pickup roller10, and a roller unit11(a pair of a driving and driven roller). The sensor30detects the presence/absence of a paper sheet in the paper feeding tray2. The pickup roller10transports the paper sheet to the roller unit11. The upper roller of the roller unit11is rotated in the direction for transporting the paper sheet toward the interior of the system, and the lower roller of the roller unit11is rotated in the direction opposite to that of the upper roller. Consequently, the roller unit11can transport the paper sheets one at a time.

In the first transporting passage, a paper sensor31, a roller12and a paper sensor32are arranged in order from the upstream side in the paper transporting direction. The paper sensor detects whether there is a paper sheet at a detecting position of the sensor. The paper sensor is not limited to an optical sensor. It may also be a mechanical sensor, a sonic wave-type sensor, or the like.

In the second transporting passage, a roller13, a paper sensor33, the scanners5and6, a paper sensor34, a roller14, the printer8, and the gate51are arranged in order from the upstream side in the paper transporting direction. Here, the scanners5,6each have an image sensor. The image sensor is, but is not limited to, a one-dimensional CCD line sensor. It may also be a two-dimensional CCD sensor. The image sensor receives the light emitted from a light source (not shown in the drawing) and reflected from the surface of the paper sheet. The image sensor detects the presence and location of an image on the sheet, as well as, wrinkles, holes, damage, etc. on the paper sheet and converts the detected information into an image data. The scanner5is arranged on the side opposite to the scanner6, with the second transporting passage sandwiched between them. The scanner5generates the image data from side of the paper sheet at a reading position55. The scanner6generates the image data from the other side of the paper sheet at a reading position56. The decoloring system1can generate the image data from both sides of each paper sheet in a single pass of the paper sheet through the second transporting passage.

The printer8has the function for printing on one side of the paper sheet being transported. This printer8is, but is not limited to, an inkjet-type printer. It may also be of electrophotographic type or thermal type or the like. The ink is made of the recording material. The gate51, located downstream in the paper transporting path from the printer, can switch the transported direction of the paper sheet to either the third transporting passage or the fourth transporting passage.

In the third transporting passage, a paper sensor35, a roller15, a roller16, paper sensors36,37, a roller17, the decoloring unit7, a paper sensor38, rollers18,19, a paper sensor39, a roller20, and a paper sensor40are arranged in order.

In the fourth transporting passage, a roller21, the gate53, a paper sensor41, a roller22, and a paper sensor42are arranged in order from the upstream side in the paper transporting direction. In the fifth transporting passage, a roller23, a paper sensor43, a roller24, and a paper sensor44are arranged in order from the upstream side in the paper transporting direction.

The paper discharge trays3and4receive the paper sheets after the end of the decoloring process. For example, the paper sheets that can be reused are accommodated in the paper discharge tray3, while the paper sheets that cannot be reused are accommodated in the paper discharge tray4.

The operation panel9has a touch panel display84, a tag reader85, and a camera93. Here, the touch panel display84is a graphical user interface (GUI), and it receives the user's instruction from the buttons, keyboard, etc. arranged in the GUI. The tag reader85reads the information from a non-contact IC tag. The user information can be read from an IC card held by the user. The tag reader85may contain a system for reading a magnetic stripe card. The camera93has a two-dimensional CCD image sensor, and it can recognize the one-dimensional or two-dimensional barcode or the like.

FIG. 2is a diagram illustrating the configuration of the decoloring unit. Here, the decoloring unit7has heating rollers60,62, pressing rollers61,63, a first heater64, a second heater65, a third heater66, temperature sensors67,68, and thermostats69,70. The paper sheet enters through an inlet71into the decoloring unit7, and it is discharged through an outlet72. The arrow indicates the transporting direction of the paper sheet through the decoloring unit7.

The heating rollers60and62are made of metal tubes. The heating roller60contains the first heater64inside it. The heating roller62contains the second heater65and the third heater66inside it. The first heater64is a halogen lamp heater with a nominal output power of 600 W. The second heater65and the third heater66each are a halogen lamp heater with nominal output power of 300 W. The heaters are not limited to the halogen lamp heaters. They may also be ceramic heaters or inductive heaters.

Pressing rollers are rollers made of a compliant material, for example, silicone rubber. The pressing roller61is arranged at the position in contact with the heating roller60. The pressing roller63is arranged at the position in contact with the heating roller62. As the heating roller and the pressing roller are rotated, the paper sheet is transported. The heating roller62is arranged on the downstream side in the paper transporting direction. The heating roller60heats on one side of the paper sheet, and the heating roller62heats on the other side of the paper sheet. That is, the heating roller60is arranged on the side opposite to the heating roller62with respect to the third transporting passage.

In contact with the surface of the heating roller64, the temperature sensor67and the thermostat69are arranged. In contact with the surface of the heating roller66, the temperature sensor69and the thermostat70are arranged. The temperature sensors67and68detect the surface temperature of the heating rollers64,66, respectively. The thermostats69and70cut off the power supply to any of the heaters64to66when the heating roller is heated to above a prescribed temperature level.

FIG. 3is a graph illustrating the function of the decoloring system. Here, a controller80of the decoloring system1has a CPU (central processing unit) or other processor81and a memory82. The memory82contains ROM (read-only memory) and RAM (random access memory), etc. Here, the ROM is for storing the programs for controlling the controller80. The RAM is for temporarily storing the programs and data files that can be used by the processor81. The controller80is connected via a bus100to an HDD (hard disk device)83, the operation panel9, a heater controller86, a transporting controller87, the scanner5, the scanner6, an image processing section91, the printer8, and a communication interface92, and it can carry out mutual communication with the devices.

The HDD83stores the image data generated by the scanner5and the scanner6. One may also adopt a flash memory or other nonvolatile memory in place of the HDD. The operation panel9has the touch panel display84, the tag reader85, and the camera93. The controller of the operation panel9controls the various devices according to the instructions from the controller80.

The heater controller86is connected to the first heater64, the second heater65, the third heater66, the temperature sensors67,68, and the thermostats69,70. Corresponding to the instructions from the controller80and the outputs of the various temperature sensors, the heater controller86controls the first heater64, the second heater65, and the third heater66.

The transporting controller87controls the motors M1to M5, an electromagnetic clutch88, a gate switching section89, and a paper feeding detecting section90. The motors M1to M5provide driving forces to the plurality of rollers. The electromagnetic clutch88controls transmission of the driving force from the motor to the roller. The gate switching section89switches the stop positions of the gates51and53. The paper feeding detecting section90receives the output from the paper sensors30to44, and detects the position of the paper sheet in the decoloring system1.

The image processing section91converts the image data generated by the scanner5and the scanner6to the image file in JPEG (Joint Photographic Expert Group), one of the image file formats, and stores them in the HDD83. The image processing section91checks the state of the paper sheet from the image data, and determines whether the paper sheet can be reused. The image processing section91is Application Specific Integrated Circuit (ASIC). However, this is not exclusive. The programs for execution in the controller80are contained.

The communication interface92is connected to the decoloring system1and a server95via a Local Area Network (LAN), a Wide Area Network (WAN), or the like. The server95contains the controller96and an HDD97. The server95receives the image data stored in the HDD83and has them stored in the HDD97. Also, the server95receives from decoloring system1the read ID from the tag reader85and the camera93, and, on the basis of the read ID, it sends the data to the decoloring system1.

FIG. 4is a diagram schematically illustrating the configuration of the interconnection between the motors and the rollers. The motor M1is connected to the rollers13and14. The motor M2is connected to the rollers15and16. The motor M3is connected to the roller17, the heating rollers60and62, the roller18, and the electromagnetic clutch88. The electromagnetic clutch88is connected to the roller19and the one-way clutch99. The one-way clutch99is connected to the roller20. When the motor M3is driven to rotate, the transporting controller87controls the electromagnetic clutch88, so that the rollers19and20can be stopped. The one-way clutch99idles when the rotation speed of the roller20is over a prescribed level. The motor M4is connected to the rollers11and12. The motor M5is connected to the rollers21to24.

FIG. 5is a reference table illustrating the relationship between the resolution of imaging of a sheet passing through the scanners5,6and the paper sheet transporting speed therethrough. For each value of a desired first scanning resolution, a speed reference table110defines a second resolution, a first read speed, an erasing speed, and a second read speed. The first resolution is the resolution set for the scanners5and6for storing the image data on the paper sheet. The user may use the operation panel9to select a first resolution. “NON” indicates that storage of the image is not carried out.

The second resolution is the resolution set for the scanners5and6for acquiring the image data of the paper sheet which was subject to decoloring process. The second resolution is a resolution for determining whether the paper sheet can be reused. According to the first embodiment, it is possible to select from two resolutions, that is, 150 dpi and 200 dpi. Corresponding to the precision of the determination on whether the paper sheet can be reused by the image processing section91, the second resolution is set. As can be appreciated from the table, the first resolution may be greater than, or less than, the second resolution.

The first reading velocity V1is the speed of a sheet provided by passing through the rollers associated with the motors M1and M3during scanning of the sheet when the scanners5and6generated the image data of the paper sheet at the first resolution. The erasing speed VE is the speed of the sheet provided by passing through the rollers associated with the motor M3when the paper sheet is transported in the third transporting passage containing the decoloring unit7. The second read speed V2is the speed of a sheet provided by passing through the rollers associated with the motor M1when the image data of the paper sheet are generated by the scanners5and6at the second resolution. As the first resolution is set to a higher value, the first read speed V1and the erasing speed VE become lower. The erasing speed VE is lower than the first read speed V1at all of values of the first resolution. At all of the values of the first resolution, the second read speed is set at a prescribed speed matching the second resolution.

FIG. 6is a reference table illustrating the relationship between the resolution and then control temperature of the heating roller when the decoloring process is carried out for both sides of the paper sheet. A temperature reference table111is taken as reference by the controller80and the heater controller86when there is an instruction on execution of the decoloring process on both sides of the paper sheet. For each value of the first resolution, the temperature reference table111sets the ON/OFF information of first, second and third heaters, a control temperature T1of the heating roller60, and a control temperature T2of the heating roller62. At all of values of the first resolution, the control temperature T1of the heating roller60is higher than the control temperature T2of the heating roller62. As the first resolution setting is increased, the control temperatures T1, T2trend lower. This is for setting a lower erasing speed VE to match the first resolution. When the control temperatures T1and T2are high and the erasing speed VE is low, a heat quantity more than what required by the paper sheet is applied. As this heat warms the scanners5and6, the scanners5and6become instable under the heat influence. According to this application example, the control temperature and the paper sheet transporting speed are selected to ensure that the decoloring process is carried out reliably without influence on the operation of the scanners5and6.

The ON/OFF information of the heater is the information for setting whether the corresponding heater is on/off when the decoloring process is carried out. The heater controller86determines whether power is supplied to the first, the second and the third heaters in the decoloring process.

FIG. 7is a table illustrating the relationship between the resolution and the control temperature of the heating roller when the decoloring process is carried out for one side of the paper sheet. A temperature reference table112is taken as reference by the controller80and the heater controller86when the user instructs execution of the decoloring process for one side of the paper sheet. For each value of the first resolution selected, the temperature reference table112sets the ON/OFF information of the first, second and third heaters, the control temperature T1of the heating roller60, and the control temperature T2of the heating roller62. When the first resolution is 150, 200, and 300 dpi, the second and third heaters are not turned on, and, as a result, the control temperature T2is not set.

FIGS. 8A to 8Dinclude diagrams illustrating transporting of the paper sheet shown in time series. As shown inFIG. 8A, a paper sheet P1fed at the feeder (not shown) has passed through the first transporting passage and the second transporting passage, and was guided by the gate51to the third transporting passage and is positioned for entry into the decoloring unit. The motors M1and M2drive the rollers13-16to move the paper sheet at a first reading velocity V1. The motor M3drives the rollers17,18,60and62to move a paper sheet at the erasing speed VE. As the paper sheet P1is transported, the scanners5and6acquire the images on the two sides of the paper sheet P1at the first resolution. As the front end of the paper sheet Plabout to enter the decoloring unit is detected by the sensor37, the motor M2drives the rollers to move the paper sheet at the erasing speed VE. The rollers15and16transport the paper sheet P1to the decoloring unit7. A second sheet P2is shown positioned before the merging point50. At the time when the trailing end of the paper sheet P1passes the paper sensor34, the paper sheet P2is transported from the first transporting passage to the second transporting passage.

As shown inFIG. 8B, the paper sheet P1has passed the decoloring unit7, and it is transported in the third transporting passage at the erasing speed VE until the front end thereof is detected by the paper sensor40. After reading of the image data by the scanners6and7and until the front end of the paper sheet P2is detected by the sensor37, the paper sheet P2is transported at the first read speed V1. At the time point when the front end of the paper sheet P1is detected by the paper sensor40, the transporting controller87checks whether the paper sheet P2is not detected by the sensors33and34. When the paper sheet P2is detected by the sensors33and34, the transporting controller87turned off the electromagnetic clutch88, so that movement of the rollers19and20is stopped. When the paper sheet P2is not detected by the sensors33and34, the motor M1has the speed changed so that the transporting speed of the sheet driven by the rollers13and14becomes the second read speed V2. The paper sheet P3is held before the merging point50.

As shown inFIG. 8C, when the sensors33and34do not detect the paper sheet P2, the transporting controller87turns on the electromagnetic clutch88, and the paper sheet P1is transported at the erasing speed VE to the second transporting passage. As the front end of the paper sheet P1enters the roller13, the paper sheet P1is transported at the second read speed V2. Because the second read speed V2is higher than the erasing speed VE, the roller20is rotated at a speed higher than the erasing speed VE. The power from the motor M3to the roller20is cut off by the one-way clutch99, so that the roller rotates while idling, i.e., while not being actively driven by the motor M3. The scanners5and6generate the image data of the paper sheet P1at the second resolution. The paper sheet P2is transported at the erasing speed VE to the decoloring unit7. The paper sheet P3stands by before the merging point50. The gate51is set at the position for guiding the paper sheet P1to the fourth transporting passage.

As shown inFIG. 8D, when the rear end of the paper sheet P1is detected by the paper sensor34, the transporting controller87controls so that the transporting speed of the rollers13and14becomes the first read speed V1. As the front end of the paper sheet P1is detected by the paper sensor41or the paper sensor43, the gate51is set at the position for guiding the paper sheet to the third transporting passage, and the paper sheet P3is transported to the second transporting passage. At this time, the paper sheet P3is sequentially detected by the sensors33and34. When the front end of the paper sheet P2is detected by the paper sensor40, the transporting controller87turns off the electromagnetic clutch88, so that the rollers19and20are stopped. When the first guided portion34does not detect the paper sheet P3, the transporting controller87turns on the electromagnetic clutch88, so that the paper sheet P2is transported into the second transporting passage. Then, until the reuse process ends for all of the paper sheets, the sequence of operation is continued.

FIG. 9is a diagram illustrating a configuration of a setup screen image adopted by the user. A setup screen image120is generated by the controller80, and it is displayed on the touch panel display84. Several buttons on the setup screen image120can be selected by the user. The controller80receives the result of the selection by the user, and carries out the reuse process. The user uses the touch panel display84, the tag reader85or the camera93to log in the decoloring system1. When the user is a prescribed user, the user name is displayed on the setup screen image120.

The setup screen image120contains a region121, a region122, and a region123. The region121is provided for storage of the data, and it has YES button and NO button indicating the presence of the instruction of storage of the image data. When the user selects the YES button, it indicates that it is possible to select several resolutions and the storage format of the image data. As the initial value, the setup screen image120for which the YES button is selected is displayed on the touch panel display84. This initial value executes the decoloring process for the paper sheet so that it works efficiently when the user fails to check up the setup.

The region122is provided for selecting one side or both sides of the paper sheet. Corresponding to the button selected by the user, the heater controller86selects either of the reference table111or112. The region123is a region for assigning an address and file name for storage of the image data generated by the scanners5and6. The user can directly input the address of the HDD83, the HDD97in the decoloring system1, and the HDD in the other network. The user can use the select button to assign the address easily.

The start button is a button for initiating the reuse process. The cancel button has the function for resetting the content selected by the user to the initial value.

FIG. 10is a flowchart illustrating an operation of the decoloring system1. As the user ID is input from the operation panel9, the controller80starts the operation of the decoloring system1(Act1). The controller80has the setup screen image120displayed on the touch panel display84. The user can use the operation panel9to select the button on the setup screen image120. As the user presses the start button on the setup screen image120, and the controller80acquires the setup information selected by the user (Act12).

The controller80checks whether the user instructs storage of the image data (Act13). When storage of the image data is instructed by the user by the operation panel9, the controller80acquires the first resolution set at the same time, and it sets the first resolution for the scanners5,6(Act14). When the user does not instruct storage of the image data, the controller80sets the first resolution as “NON”. The controller80reads the reference table110, and it acquires the data of the V1, VE, V2on the basis of the set first resolution (Act15). The transporting controller87sets V1for the motors M1and M2, and sets VE for the motor M3(Act16).

On the basis of the setup information of one side or both sides that has been set, the controller80selects the reference table111or the reference table112. On the basis of the set first resolution, the controller80acquires the control temperature data from the selected temperature reference table (Act17). The controller80then checks whether the control temperature T2is set (Act18). When the control temperature T2is set, the heater controller86starts turning on of the first, second and third heaters (Act19).

The heater controller86keeps the first heater ON until the temperature T1′ detected by the temperature sensor67exceeds the control temperature T1. The heater controller86keeps the second and third heaters ON until the temperature T2′ detected by the temperature sensor68becomes over the control temperature T2.

In Act18, when the control temperature T2is not set, the heater controller86starts turning on the first heater (Act21). The first heater is kept ON until the temperature T1′ detected by the temperature sensor67exceeds the control temperature T1(Act22). When T1′ and T2′ become over a prescribed temperature, the controller80reads the ON/OFF information of the first to third heaters from the temperature reference table. The heater controller86determines which heater should be turned on during the decoloring process on the basis of the ON/OFF information (Act23). When all of the information has been set, and the warming-up of the decoloring system1ends, and the controller80carries out the reuse process (Act24). After end of all of the reuse processing, the image data generated by the scanners5and6are stored at the assigned address in the network (Act25).

FIGS. 11 and 12are flow charts illustrating a reuse process. The reuse process is carried out for one paper sheet at a time. In practice, however, the controller80may carry out the same or similar processing in parallel for the various paper sheets under process.

Referring toFIG. 11andFIG. 1, after the start of Act24, the rollers10,11, and12(FIG. 1) rotate to pick up the paper sheet in the paper feeding tray2, and transport it into the first transporting passage (Act30). The transporting controller87(FIG. 2) checks whether the sensors33and34in the second transporting passage detect the paper sheet (Act31). When the sensors33and34do not detect the paper sheet, the transporting controller87has the motor M4turned on, and has the paper sheet in the first transporting passage transported to the second transporting passage (Act32). The controller80checks whether storage of data is assigned by the setup screen image120(Act33). When the user assigns storage of the image data, the scanners5and6generate the image data from both sides of the paper sheet (Act34).

The transporting controller87controls so that the motor M2is at the first read speed V1until the front end of the paper sheet is detected by the sensor36(Act35). When the sensor36detects the front end of the paper sheet, the transporting controller87controls the motor M2so that the paper sheet transporting speed is changed to the erasing speed VE (Act36). As the motor M2changes the paper sheet transporting speed to the erasing speed VE, the paper sheet is transported to the decoloring unit7, and the decoloring process is carried out (Act37). While the sensor36detects the paper sheet, the motor M2has the paper sheet transporting speed kept at VE (Act38).

When it becomes the state in which the sensor36does not detect the paper sheet, the transporting controller87changes the motor M2so that the speed becomes the first read speed V1(Act39). The transporting controller87waits for the paper sensor40to detect the front end of the paper sheet that has passed the decoloring unit7(Act40). When the paper sensor40detects the front end of the paper sheet, the transporting controller87checks whether the sensors33and34detect another paper sheet (Act41). When the sensors33and34detect another paper sheet, the transporting controller87turns off the electromagnetic clutch, so that the paper sheet in the third transporting passage is stopped (Act42).

When the sensors33and34do not detect another paper sheet, the transporting controller87controls so that the motor M2achieves the second read speed V2for the sheet (Act43). The electromagnetic clutch is changed so that it is turned on, and the paper sheet in the third transporting passage is transported to the second transporting passage. The scanners5and6generate the image data from both sides of the paper sheet at the second resolution (Act45). The image processing section91analyzes this image data, and determines whether the paper sheet can be reused (Act46).

When the paper sheet can be reused, the paper sheet is transported to the paper discharging tray3(Act47). When the paper sheet cannot be reused, the paper sheet is transported to the paper discharging tray4(Act48). When there is a paper sheet in the paper feeding tray3, the controller80returns to Act30. When there is no paper sheet in the paper feeding tray3, the controller80sends the image generated by the scanners5and6to the assigned address on the network, and the entire process comes to an end.

The decoloring system1in the first embodiment can control to have the optimum paper sheet transporting speed and the temperature of the heating rollers on the basis of the presence of the image data and the resolution set by the user. As the paper sheet is not excessively heated, it is possible to cut the power consumption. Also, it is possible to alleviate the adverse influence of the heat of the paper sheet on the scanners.

According to the first embodiment, the controller80, the heater controller86, and the transporting controller87in the decoloring system1work together to control the decoloring system1. The various functions of these controllers can be also carried out under control of one controller. Also, one may also adopt a configuration wherein the various functions are executed by the plurality of controllers including the server95and other controllers in the network and the controllers in the decoloring system1.

The various functions may also be carried out by ASIC or other hardware circuit, and they may also be carried out by the program executed by the CPU in the controller.