JP2010133998A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of making paint, which becomes colorless when heated, on an original including a part drawn in such paint colorless with small power consumption. <P>SOLUTION: After finishing a printing job, the original including the part drawn in the paint, which becomes colorless, is fed and conveyed from a manual feeding tray 24 and made to pass through a fixing device 22, thereby the paint becomes colorless by remaining heat of the fixing device 22. While raising temperature of the fixing device 22 in preparation to start the printing job, the original is fed and conveyed and made to pass through the fixing device 22, so as to make the paint colorless. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image forming apparatus that heats and fixes a toner image formed on a recording sheet by a fixing device.

  2. Description of the Related Art Conventionally, from the viewpoint of effective use / reuse of paper resources, there is a writing instrument using ink that becomes colorless when heated to a high temperature such as 60 ° C. or higher. In addition, there is an ink jet printer that includes a recording unit that uses ink that becomes colorless when heated, and a heating unit that is disposed in front of the recording unit and that decolorizes ink (see, for example, Patent Document 1).

JP 2001-302954 A

  When the personal information entered on the questionnaire form is read and digitized by a scanner and stored and managed in a database, etc., the electronic form is properly disposed of to prevent leakage of personal information, etc. Is required. In such a case, if the writing is performed using the above-described writing tool that uses the ink that becomes colorless by heating, it is possible to prevent the leakage of personal information by erasing the written portion by heating the paper after reading and digitizing. . Furthermore, if only the entered part is erased, it can be reused as an unfilled questionnaire.

  However, in a configuration in which a dedicated device for erasing is provided, or the ink is made colorless by heating a dedicated heating unit as in the ink jet printer disclosed in Patent Document 1, power consumption for the colorlessness increases. There is a problem.

  The present invention is intended to solve the above-described problem, and performs a colorless process for colorlessizing a paint including a portion drawn with a paint that becomes colorless when heated with less power consumption. An object of the present invention is to provide an image forming apparatus capable of performing the above.

  The gist of the present invention for achieving the object lies in the inventions of the following items.

[1] An image forming unit that forms a toner image on recording paper;
A fixing device that heats and fixes the toner image formed on the recording paper by the image forming unit to the recording paper;
A first transport unit that transports the recording paper stored in the first paper storage unit to a predetermined paper discharge destination via the image forming unit and the fixing device;
A second transport unit configured to transport a document including a portion drawn with a paint that becomes colorless when heated stored in the second paper storage unit to a predetermined discharge destination via the fixing unit;
Controls execution of a print job in which the recording paper stored in the first paper storage unit is transported to the first transport unit, and a toner image is formed on the recording paper by the image forming unit and fixed by the fixing device. At the same time, after the print job is finished, the document stored in the second sheet storage unit is transported to the second transport unit, and the paint drawn on the document is made colorless by the residual heat of the fixing device. A control unit for performing an erasing process, and
An image forming apparatus comprising:

  In the above-described invention, the erasing process for colorlessizing the paint including the portion drawn with the paint that becomes colorless when heated is performed using the residual heat of the fixing device after the print job is completed.

[2] A temperature sensor for detecting the temperature of the fixing device is provided,
The image forming apparatus according to [1], wherein the control unit terminates the erasing process when the temperature detected by the temperature sensor becomes lower than a predetermined temperature after the print job is completed.

  In the above invention, the erasing process performed after the end of the print job is ended when the temperature of the fixing device detected by the temperature sensor becomes lower than the predetermined temperature. Since the end of the erasing process is determined by the temperature sensor, the end can be determined more accurately, and the number of erasable sheets can be made as close as possible by using residual heat.

[3] The image forming apparatus according to [1], wherein the control unit ends the erasing process when a predetermined time has elapsed after the print job is completed.

  In the above invention, the end of the erasing process is determined based on the elapsed time after the end of the print job. Compared with the case of determining the end based on the temperature of the fixing device, the end can be easily determined, and the control and the apparatus configuration are simplified.

[4] The image forming apparatus according to [1], wherein after the print job is finished, the control unit finishes the erasing process when a predetermined number of sheets are applied.

  In the above invention, the end of the erasure process is determined based on the number of sheets that have been erased after the end of the print job. Compared with the case of determining the end based on the temperature of the fixing device, the end can be easily determined, and the control and the apparatus configuration are simplified.

[5] The control unit stops the erasure process when the next print job is input during execution of the erasure process after the print job is completed. [1] to [4] ] The image forming apparatus according to any one of the above.

  In the above invention, when the next print job is input during the erasing process after the end of the print job, the subsequent erasing process is stopped. As a result, heat consumption due to the erasing process is eliminated, and the temperature of the fixing device for the next print job can be quickly increased.

[6] The control unit starts execution of the next print job without performing the erasure process if the next print job has already been submitted at the end of the print job. [1] The image forming apparatus according to any one of [5] to [5].

  In the above invention, when there is a next print job at the end of the print job, control is performed so that the erasure process is not performed between the print jobs.

[7] The control unit is further housed in the second paper storage unit in the second transport unit while the temperature of the fixing device is raised to a predetermined fixing possible temperature in preparation for starting a print job. Any one of [1] to [6], wherein the document is transported and an erasing process is performed in which the paint drawn on the document is colorless by heat of the fixing device. Image forming apparatus.

  In the above invention, the erasing process is also performed while the temperature of the fixing device is raised in preparation for starting the print job.

[8] When the number of documents stored in the second sheet storage unit is equal to or less than a predetermined number when the temperature of the fixing unit reaches the fixable temperature, the control unit starts the print job. The image forming apparatus according to [7], wherein the erasing process is continued until the document stored in the second sheet storage unit is exhausted.

  In the above invention, when the erasing process is performed while the temperature of the fixing device is raised, and the remaining number of documents to be erased is equal to or less than the predetermined number upon completion of the temperature raising, the start of the print job is delayed and the erasing process is performed. Will continue.

[9] A plurality of paper discharge trays used for switching between the paper discharge destination of the first transport unit and the paper discharge destination of the second transport unit,
The control unit causes the erasing process at the time of the temperature increase to be performed by selecting a paper discharge tray that is not designated as a paper discharge destination of a waiting print job as a paper discharge destination [7] to [8] The image forming apparatus according to any one of [8].

  In the above-described invention, a paper discharge tray that is not designated as a paper discharge destination in a print job executed after completion of the temperature rise is selected as the paper discharge destination related to the erasing process at the time of temperature rise. The erased document is ejected to a paper output destination that is different from the paper output destination for the print job that is executed after the temperature rise is completed, and the printed matter related to the print job is placed on the erased document and is not noticed. It is possible to prevent erroneous collection such that the user takes away the erased document together with the printed matter.

[10] The control unit does not perform the erasing process at the time of the temperature rise if there is no discharge tray not designated as a discharge destination of the waiting print job [9] ] The image forming apparatus described in the above.

  In the above invention, there is no paper discharge tray that is not designated as a paper discharge destination in a print job that is executed after the temperature rise is completed (all paper discharge trays are designated as paper discharge destinations for one of the waiting print jobs) ), The erasing process at the time of temperature rise is prohibited. This is to prevent erroneous collection.

  According to the image forming apparatus of the present invention, the erasing process of erasing the paint including the portion drawn with the paint that becomes colorless when heated is performed using the residual heat of the fixing device after the end of the print job. Thus, power consumption required for the erasing process can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a cross-sectional configuration of an image forming apparatus 10 according to an embodiment of the present invention. The image forming apparatus 10 optically reads a document to acquire image data, stores the image data or transmits the image data to an external terminal, reads the document, and based on the image data obtained by the reading A copy function that prints a copy of a document on recording paper and outputs it, and a printer function that prints an image corresponding to image data obtained by rasterizing print data received from an external terminal and outputs it Further, it is configured as a so-called multifunction machine.

  Further, the image forming apparatus 10 erases the portion drawn with the paint by heating the document including the portion drawn with the paint that becomes colorless when heated (hereinafter referred to as the colorless paint). The process is configured to be executable.

  The image forming apparatus 10 includes a reading unit 11 that reads a document image, an automatic document conveying device 12 that feeds documents placed on a document tray 12a one by one to a document reading position of the reading unit 11, and forms an image on a sheet. The printer unit 20 for outputting and the operation display unit 14 are provided.

  The reading unit 11 includes a light source that irradiates light on a document, a line image sensor 11a that reads the document for one line in a direction perpendicular to the transport direction (sub-scanning direction) of the automatic document transport device 12, and reflected light from the document. The optical path includes a lens or a mirror that is guided to the line image sensor 11a to form an image. In the image forming apparatus 10, as a document reading method, a document stationary on the platen glass is read two-dimensionally by optically moving the reading position of the reading unit 11, and conveyed by the automatic document conveying device 12. There is provided a so-called flow reading format in which a document is repeatedly read line by line at a fixed reading position to obtain a two-dimensional image. The analog image signal output from the line image sensor 11 a is converted into digital image data and output from the reading unit 11.

  The printer unit 20 includes an image forming unit 21 that forms a toner image on a sheet, a fixing unit 22 that heats and fixes the toner image formed on the sheet by the image forming unit 21, and a plurality of sheets. Can be stored in the paper feed tray 23, the manual feed tray 24, the first paper discharge tray 25, the second paper discharge tray 26, the paper stored in the paper feed tray 23 or the manual feed tray 24. ) Is provided with a conveyance unit 27 that conveys the sheet to the first paper discharge tray 25 or the second paper discharge tray 26 via the image forming unit 21 and the fixing device 22.

  The manual feed tray 24 is provided with a sensor (not shown) that detects whether or not paper is set in the manual feed tray 24.

  The fixing device 22 is provided with a temperature sensor 28 for detecting the temperature. Specifically, the temperature sensor 28 detects the surface temperature of the fixing roller that presses and contacts the paper to be conveyed.

  When the paper is fed from the paper feed tray 23, the transport unit 27 transports the paper stored in the paper feed tray 23 to the paper discharge destination via the image forming unit 21 and the fixing device 22. When the paper is fed from the manual feed tray 24, it functions as a second transport unit that transports the paper stored in the manual feed tray 24 to the paper discharge destination via the fixing device 22. Here, the recording paper used for image formation is stored in the paper feed tray 23, and a document including a portion drawn with a paint that becomes colorless when heated (hereinafter referred to as “recycled paper”) is the manual feed tray 24. It shall be stored in. It should be noted that any one of a plurality of paper feed trays 23 can be set to be used for storing reclaimed paper.

  The image forming unit 21 includes a photoreceptor 31, a charging device 32, a laser unit 33, a developing device 34, a transfer device 35, a separating device 36, a cleaning device 37, and the like. Form on top.

  Specifically, the photoconductor 31 has a cylindrical shape and is rotated in a certain direction (the direction of arrow A in the drawing) by a driving unit (not shown). During rotation, the photoreceptor 31 is uniformly charged by corona discharge by the charging device 32, and then receives a scanning of laser light which is turned on / off according to image data from the laser unit 33, and an electrostatic latent image is formed on the surface thereof. Is formed. The developing device 34 visualizes the electrostatic latent image formed on the surface of the photoreceptor 31 as a toner image.

  The transport unit 27 feeds the paper from the paper feed tray 23 and transports the paper between the photoconductor 31 and the transfer device 35 at an appropriate timing. The transfer device 35 electrostatically transfers the toner image formed on the surface of the photoconductor 31 onto the paper conveyed by the conveyance unit 27, and the separation device 36 removes the paper from the photoconductor 31 by static elimination. To separate. The cleaning device 37 removes the toner remaining on the photoreceptor 31 after the transfer by rubbing with a blade or the like. The sheet on which the toner image has been transferred is further transported and pressurized and heated when passing through the fixing device 22 to fix the toner image on the sheet, and then the first discharge tray 25 or the second discharge tray 26. Is discharged.

  Which of the first discharge tray 25 and the second discharge tray 26 is discharged is switched depending on the direction of the switching claw of the switching unit 29. The switching claw of the switching unit 29 is normally urged by a spring (not shown) to a first position (a position indicated by a broken line in FIG. 1) for guiding paper to the first paper discharge tray 25, and is energized by a solenoid. Sometimes, it is displaced against the spring to a second position (a position indicated by a solid line in FIG. 1) for guiding the sheet to the second sheet discharge tray 26.

  FIG. 2 shows an electrical schematic configuration of the image forming apparatus 10. The image forming apparatus 10 includes a reading unit 11, an automatic document feeder 12, a communication unit 42, an image storage unit 43, a nonvolatile memory 44, and a control unit 41 that performs overall control of the operation of the image forming apparatus 10. The operation display unit 14 and the printer unit 20 are connected.

  The control unit 41 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like that are not shown in the figure. Various programs are stored in the ROM, and the functions of the image forming apparatus 10 are realized by the CPU executing processes according to these programs. The RAM is used as a work memory that temporarily stores various data when the CPU executes a program. The nonvolatile memory 44 stores user information and various setting information that should be saved even when the power is turned off.

  The communication unit 42 functions to communicate with various devices on the network by connecting to a network such as a LAN (Local Area Network) or the Internet. For example, it is used when image data obtained by reading by the reading unit 11 is transmitted to an external terminal or when print data to be printed is received from the external terminal.

  The image storage unit 43 is a nonvolatile mass storage device used for storing image data obtained by rasterizing print data, image data obtained by reading by the reading unit 11, and the like. Here, the image storage unit 43 includes a hard disk device and its controller.

  The operation display unit 14 functions to display various operation screens, setting screens, selection screens, guidance screens, and the like and to receive various operations from the user. Here, it is composed of a liquid crystal display (LCD ...) that assumes the display function, a touch panel that is formed on the surface of the liquid crystal display and detects the pressed coordinate position, a numeric keypad, a start button, and various operation switches. The

  Next, a printing-related operation performed by the image forming apparatus 10 (a printing operation related to a print job and an operation for performing a erasing process of the recycle paper required in association therewith) will be described.

  FIG. 3 shows a temperature change of the fixing device 22 when the image forming apparatus 10 performs a print job. As preparation for starting a print job, first, the controller 41 controls the temperature of the fixing device 22 to a predetermined fixable temperature F (temperature increase period: T0 to T2). For example, the fixable temperature F is set to 120 ° C. During execution of a print job (during printing), heating of the fixing device 22 (energization to the fixing device 22) is controlled so as to maintain the temperature of the fixing device 22 at a fixing possible temperature F (or F + several degrees Celsius) ( T2-T3). When the print job ends, heating (energization) of the fixing device 22 is stopped (T3), and the temperature of the fixing device 22 gradually decreases (cooling period: T3 to T5).

  The colorless temperature G, which is the temperature of the fixing device 22 capable of removing the colorless coating material of the recycled paper that passes through the fixing device 22, is lower than the fixing temperature F, and is 60 ° C. here. Therefore, if the temperature of the fixing device 22 is equal to or higher than the colorless temperature G and a period when the print job is not being executed (during printing) and the recycled paper is transported and passed through the fixing device 22, the heat of the fixing device 22 is increased. The recycled paper can be made colorless by using it. For example, in FIG. 3, the period from T1 to T2 in the temperature rising period and the period from T3 to T4 in the cooling period are erasable periods in which the paper that needs to be recycled can be colorless.

  First, a description will be given of a case where the paper to be recycled is made colorless (erasing process) using the erasable period in the cooling period. The end of the erasing process performed using the erasable period of the cooling period is determined based on one of the elapsed time after the job ends, the number of processed sheets in the erasing process after the job ends, and the temperature of the fixing device 22.

  The colorless temperature G is set according to the type of the colorless paint and is stored in the nonvolatile memory 44.

  FIG. 4 is a flow of printing-related operations when the image forming apparatus 10 performs the erasing process using the erasable period in the cooling period, and determines the end of the erasing process based on the elapsed time after the end of the job. Shows the behavior of the case.

  Prior to the start of the print job, the control unit 41 of the image forming apparatus 10 raises the temperature of the fixing device 22 to the fixable temperature F (step S101), and when the temperature rise is completed, executes the printing operation related to the print job ( Step S102). Specifically, in the printing operation, paper is fed from the paper feed tray 23, and the paper is transported by the transport unit 27 to the first paper discharge tray 25 via the image forming unit 21 and the fixing device 22. During the conveyance, the image forming unit 21 forms a toner image on the paper, and the fixing device 22 fixes the toner image on the paper. When printing a plurality of sheets in the print job, the above printing operation is continuously repeated.

  When the execution of the print job is completed, the control unit 41 stops energizing the fixing device 22. As a result, the fixing device 22 enters the cooling period of FIG. The control unit 41 checks whether or not there is a sheet that needs to be recycled (set) in the manual feed tray 24 (step S103). If there is no sheet that needs to be recycled (step S103; No), the process ends.

  If there is a sheet that needs to be recycled in the manual feed tray 24 (step S103; Yes), it is checked whether or not a predetermined time has elapsed from the end of the print job (step S104). An erasing process for one sheet of reclaimed paper is performed (step S105).

  The predetermined time in step S104 is obtained in advance from the temperature change characteristics of FIG. For example, in the case of FIG. 3, the predetermined time is set to (T4-T3-room time). The allowance time is set in anticipation that the temperature drop is accelerated by performing the erasing process. Note that the predetermined time may be set by actually measuring the temperature decrease characteristic in the cooling period when the erasing process is executed. In this case, the margin time may be zero. Alternatively, the predetermined time may be corrected (for example, multiplied by a coefficient corresponding to the outside air temperature) according to the outside air temperature.

  In the erasing process of step S105, the requisite paper is fed from the manual feed tray 24, and the reclaimed paper is conveyed by the conveyance unit 27 to the second discharge tray 26 via the image forming unit 21 and the fixing device 22. The discharge operation is performed. During the conveyance, the image forming unit 21 does not form a toner image. The reclaimed paper is heated when passing through the fixing device 22, and the colorless paint portion is colorless (erased).

  After executing the erasing process for one sheet of requisite paper, the control unit 41 checks whether there is a next requisite paper in the manual feed tray 24 (step S103; No), and ends this process. Even when there is a next sheet to be recycled, if a predetermined time has elapsed after the end of the job (step S104; Yes), the process is terminated.

  As described above, since the erasing process is performed using the residual heat of the fixing device 22 after the print job is completed, it is possible to reduce the power consumption necessary for making the paper to be recycled colorless. Further, since the end of the erasure process is determined based on the elapsed time, the processing load related to the determination is small.

  FIG. 5 is a printing-related operation in the case where the image forming apparatus 10 performs the erasing process using the erasable period in the cooling period, and determines the end of the erasing process based on the number of processed sheets after the job ends. The flow of operation is shown.

  The same processes as those in FIG. 4 are denoted by the same step numbers. Prior to the start of the print job, the control unit 41 of the image forming apparatus 10 raises the temperature of the fixing device 22 to the fixable temperature F (step S101), and when the temperature rise is completed, executes the printing operation related to the print job ( Step S102). When the execution of the print job is completed, the control unit 41 stops energizing the fixing device 22. As a result, the fixing device 22 enters the cooling period of FIG. The control unit 41 checks whether or not there is a sheet requiring regeneration on the manual feed tray 24 (step S103). If there is no sheet requiring regeneration (step S103; No), the process is terminated.

  If there is a sheet that needs to be recycled in the manual feed tray 24 (step S103; Yes), it is checked whether or not the number of sheets that require erasing after the end of the print job has reached a predetermined number (step S114). If the number is less than the number of sheets (step S114; No), the erasing process for one sheet of requisite paper is performed (step S105), and the process proceeds to step S103. When the number of sheets of reclaimed paper that have been erased since the end of the print job has reached a predetermined number (step S114; Yes), the process ends.

  The predetermined number of sheets in step S114 is obtained in advance based on the number of erased sheets at the time when the temperature drop characteristic of the fixing device 22 in the cooling period when the erasing process is being performed and the temperature drops to the colorless temperature G. (For example, a number that is less than the number of erasures by one or two margins) and the number is stored in the nonvolatile memory 44. In addition, a predetermined number of sheets may be corrected (for example, multiplied by a coefficient corresponding to the outside air temperature or the size of the reclaimed paper) according to the outside air temperature or the size of the reclaimed paper.

  FIG. 6 is a printing-related operation when the image forming apparatus 10 performs an erasing process using the erasable period in the cooling period, and an operation when the end of the erasing process is determined based on the temperature of the fixing device 22. Shows the flow.

  The same processes as those in FIG. 4 are denoted by the same step numbers. Prior to the start of the print job, the control unit 41 of the image forming apparatus 10 raises the temperature of the fixing device 22 to the fixable temperature F (step S101), and when the temperature rise is completed, executes the printing operation related to the print job ( Step S102). When the execution of the print job is completed, the control unit 41 stops energizing the fixing device 22. As a result, the fixing device 22 enters the cooling period of FIG. The control unit 41 checks whether or not there is a sheet requiring regeneration on the manual feed tray 24 (step S103). If there is no sheet requiring regeneration (step S103; No), the process is terminated.

  If there is a sheet that needs to be recycled on the manual feed tray 24 (step S103; Yes), it is checked whether or not the temperature of the fixing device 22 detected by the temperature sensor 28 is equal to or higher than the colorless temperature G (step S124). If it is above (step S124; Yes), the erasing process for one sheet of requisite paper is performed (step S105), and the process proceeds to step S103. If the temperature of the fixing device 22 detected by the temperature sensor 28 is lower than the colorless temperature G (step S124; No), the process is terminated.

  The temperature (colorless temperature G) that serves as the determination criterion in step S124 is obtained in advance and stored in the nonvolatile memory 44. A temperature obtained by adding a predetermined margin temperature (for example, 5 ° C.) to the colorless temperature G may be used as the colorless temperature used for the comparison in step S124.

  As described above, since the erasing process is performed using the residual heat of the fixing device 22 after the print job is completed, it is possible to reduce the power consumption necessary for making the paper to be recycled colorless. Further, since the end of the erasing process is determined based on the temperature of the fixing device 22 detected by the temperature sensor 28, the erasing process can be performed as compared with the case where the elapsed time after the end of the job or the number of erasing processes is used as a reference. The end stage can be determined more accurately, and the erasing process can be performed on a closer number of sheets of recycled paper required.

  Next, a case where the erasing process is performed using an erasable period (such as T1 to T2 in FIG. 3) in the temperature rising period will be described.

  FIG. 7 shows the flow of the temperature raising process performed by the image forming apparatus 10 when the erasing process is performed using the erasable period in the temperature raising period. This process is performed in place of step S101 in FIG. 4, FIG. 5, and FIG. The control unit 41 turns on the energization to the fixing device 22 and starts temperature increase (step S201). Next, the temperature of the fixing device 22 (detected value of the temperature sensor 28) is acquired (step S202). If the temperature of the fixing device 22 is lower than the fixable temperature F (step S203; No), the temperature of the fixing device 22 is obtained. It is checked whether or not the temperature is equal to or higher than the colorless temperature G (step S204).

  If the temperature of the fixing device 22 is lower than the colorless temperature G (step S204; No), the process returns to step S202 to continue the process (continuous temperature increase). If the temperature is equal to or higher than the decolorization temperature G (step S204; Yes), it is checked whether or not there is a sheet that needs to be recycled in the manual feed tray 24. Continue (continuous temperature rise).

  If there is a sheet that needs to be recycled (step S205; Yes), an erasure process is performed for one sheet that needs to be recycled (step S206). In step S206, the same erasure process as step S105 shown in FIG. In other words, the reclaimed paper is fed from the manual feed tray 24, and the reclaimed paper is transported by the transport unit 27 to the second paper discharge tray 26 via the image forming unit 21 and the fixing device 22. During the conveyance, the toner image is not formed by the image forming unit 21, and the regenerated paper is heated when passing through the fixing device 22, and the colorless paint portion is colorless (erased).

  When the temperature of the fixing device 22 reaches the fixable temperature F (step S203; Yes), this process ends.

  As described above, since the temperature of the fixing device 22 is raised during the preparation for starting the print job, the erasing process is performed on the recycled paper using a period in which the temperature is higher than the colorless temperature G and lower than the fixable temperature F. It is possible to reduce the power consumption required to make the paper colorless.

  In the operations described so far, it is preset that the paper after image formation is discharged to the first paper discharge tray 25, and the paper after the erasure process is discharged to the second paper discharge tray 26. 2 The paper discharge tray 26 is a dedicated paper discharge destination for the paper after the erasing process.

  On the other hand, it is possible to specify a paper discharge destination for each print job. In this case, it is preferable to automatically select a paper discharge destination different from the paper discharge destination specified in the print job as the paper discharge destination for the erasing process.

  In particular, when an erasing process is performed while the temperature is rising, a print job is executed after the erasured recycled paper is discharged to the paper discharge tray. For this reason, when the printed material related to the print job is discharged to the same paper discharge tray as the paper discharge tray from which the erased reclaimed paper is discharged, the printed material is placed on the erased reclaimed paper. Therefore, there is a possibility that the user who has collected the printed material may take home the erased recycled paper together with the printed material without noticing the presence of the erased recycled paper hidden under the printed material. In view of this, in the image forming apparatus 10, it is possible to execute control to select a paper discharge destination in the erasing process during the temperature rise so as not to overlap with a paper discharge destination related to a print job to be performed thereafter. .

  FIG. 8 shows the flow of the temperature raising process in a case where control is performed so that the paper discharge destination of the erasing process during the temperature rise does not overlap with the paper discharge destination related to the print job to be performed thereafter. This process is performed in place of step S101 in FIGS. 4, 5, and 6, or the temperature raising process in FIG.

  The control unit 41 turns on the energization to the fixing device 22 and starts the temperature increase (step S221). Next, the temperature of the fixing device 22 (detected value of the temperature sensor 28) is acquired (step S222). If the temperature of the fixing device 22 is lower than the fixable temperature F (step S223; No), all waiting jobs are acquired. The output destination (the paper discharge tray designated as the output destination in the waiting job) is confirmed (step S224). The waiting job is a print job that has been submitted and has not yet been executed, and refers to a print job that has caused the current temperature increase and a print job that is scheduled to be executed subsequently.

  The control unit 41 checks whether there is a paper discharge tray not designated as an output destination in any of the waiting jobs (step S225), and if there is a paper discharge tray not designated as an output destination (step S225). ; Yes), the non-designated paper discharge tray (if any) is set as the paper discharge destination for the erasing process (step S226). If the temperature of the fixing device 22 becomes equal to or higher than the colorless temperature G (step S227; Yes) and there is a recycle paper that is required on the manual feed tray 24 (step S228; Yes), an erasure process of one recycle paper is performed ( Step S229) The process returns to step S222. In the erasing process performed in step S229, the erasure-required paper that has been erased is discharged to the paper discharge tray set as the paper discharge destination in step S226.

  For example, when there are the first paper discharge tray 25 and the second paper discharge tray 26 and the output destinations of all the waiting jobs are the first paper discharge tray 25, the second paper discharge tray 26 is used as the output destination of the erasing process. Is selected.

  When there is no paper discharge tray not specified as the output destination of the waiting job (step S225; No), or the temperature of the fixing device 22 is lower than the colorless temperature G (step S227; No) or the manual feed tray 24 needs to be recycled. If there is no error (step S228; No), the process returns to step S222 without performing the erasing process, and waits for the fixing device 22 to reach the fixable temperature F. Then, when the fixing possible temperature F is reached (step S223; Yes), this processing is terminated.

  For example, when there are the first discharge tray 25 and the second discharge tray 26, the output destination of the first standby job is the first discharge tray 25, and the output destination of the second standby job is the first. In the case of the two paper discharge trays 26, since there is no other paper discharge tray, the erasing process is stopped.

After completion of the temperature raising process, the print jobs that have been waiting are sequentially executed.

  As described above, when a discharge destination that is different from the discharge destination of the printed matter related to the print job performed after the completion of the temperature increase is selected as the discharge destination in the erasing process during the temperature increase, and a different discharge destination cannot be selected. Is controlled so as not to perform the erasing process during the temperature rise, so that the printed matter of the print job to be executed thereafter is placed on the recycled paper that has been erased by the erasing process during the temperature rise. Is prevented. Accordingly, it is possible to prevent an erroneous collection in which a user who has come to collect printed materials takes away erased recycled paper hidden under the printed materials together with the printed materials.

  Next, a case where the next print job is input while the erasing process is performed during the erasable period of the cooling period will be described.

  FIG. 9 shows an example of the temperature change of the fixing device 22 when the next print job is input during the erasable period of the cooling period. When a print job currently being executed is completed without a print job waiting (T3), heating (energization) of the fixing device 22 is stopped, a cooling period starts, and the temperature of the fixing device 22 gradually decreases (T3). ~ T7). When the next print job is input before the temperature of the fixing device 22 decreases to the colorless temperature G (T7), the temperature of the fixing device 22 starts to be raised toward the fixing possible temperature F, and the fixing possible temperature F is reached. When the temperature rises to (T8), execution of the print job is started.

  FIG. 10 shows a flow of printing-related operations corresponding to a case where the next print job is input during execution of the erasing process in the cooling period. In the process of FIG. 10, when the next print job is input during execution of the erasing process in the cooling period, the erasing process is stopped at that point.

  Prior to the start of the print job, the control unit 41 of the image forming apparatus 10 raises the temperature of the fixing device 22 to the fixable temperature F (step S301), and executes a print operation related to the print job (step S302). If the next print job has already been input at the end of the print job (step S303; Yes), the next print job is continuously executed (step S302).

  If there is no next print job (step S303; No), the control unit 41 stops energization of the fixing device 22. As a result, the fixing device 22 enters a cooling period. After that, the control unit 41 checks whether or not there is a sheet that needs to be recycled in the manual feed tray 24 (step S304). If there is no sheet that needs to be recycled (step S304; No), the process ends.

  If there is a sheet that needs to be recycled on the manual feed tray 24 (step S304; Yes), it is checked whether or not the temperature of the fixing device 22 detected by the temperature sensor 28 is equal to or higher than the colorless temperature G (step S305). If it is above (step S305; Yes), the erasing process for one sheet of recycle paper that is required is performed (step S306). Note that the determination in step S305 may be based on whether a predetermined time has elapsed from the end of the print job as in step S104 of FIG. 4, or the erasure after the end of the print job as in step S114 of FIG. The determination may be based on the number of processed sheets.

  If the temperature of the fixing device 22 detected by the temperature sensor 28 is not equal to or higher than the colorless temperature G (Step S305; No), the process is terminated. If the temperature of the fixing device 22 is equal to or higher than the colorless temperature G (step S305; Yes), after performing the erasure process for one sheet of paper to be recycled (step S306), it is determined whether or not the next print job has been input. It investigates (step S307). If the next print job has not been input (step S307; No), the process proceeds to step S304 and the process is continued. That is, as long as the conditions of steps S304 and S305 are satisfied, the erasing process for the next reclaimed paper is continued.

  When the next print job is input (step S307; Yes), the subsequent erasing process on the paper to be recycled is stopped and the process returns to step S301, and the fixing device 22 is heated to the fixing possible temperature F.

  As described above, when the next print job is input during the erasing process in the cooling period, the erasing process for the paper to be recycled after that is stopped and the temperature of the fixing device 22 is raised. Is no longer consumed, and accordingly, the temperature rise time to the fixing possible temperature F can be shortened.

  FIG. 11 is another example of the printing-related operation corresponding to the case where the next print job is input during execution of the erasing process in the cooling period, and the erasing process is continued even after the next print job is input. Shows the operation. Parts having the same operations as those in FIG. 10 are denoted by the same step numbers, and description of the same parts is omitted. FIG. 11 is different from the operation of FIG. 10 in the operation after “Yes” in step S307.

  When the next print job is input during execution of the erasing process in the cooling period (step S307; Yes), the control unit 41 starts increasing the temperature of the fixing device 22 (step S308). Subsequently, the temperature of the fixing device 22 (detected value of the temperature sensor 28) is acquired (step S309). If the temperature has not reached the fixable temperature F (step S310; No), the manual feed tray 24 needs to be recycled. If there is no sheet to be recycled (step S311; No), the process returns to step S309 and the process is continued. In this case, it is guaranteed that the temperature of the fixing device 22 is equal to or higher than the colorless temperature G (temperature increase is started before the temperature decreases below the colorless temperature G). Determination of whether or not the temperature is equal to or higher than the colorless temperature G is omitted.

  If there is a sheet that needs to be recycled (step S311; Yes), a process for erasing one sheet that needs to be recycled is performed (step S312), and the process proceeds to step S309.

  When the fixing device 22 reaches the fixable temperature F (step S310; Yes), the control unit 41 checks the number of sheets of reclaimed paper remaining on the manual feed tray 24 at this time, and the remaining number of sheets of reclaimed paper is the predetermined number M. Is exceeded (step S313; No), the process proceeds to step S302, and the next print job is executed. The predetermined number M is preset and stored in the nonvolatile memory 44. The value of M is set to 2 sheets, for example. The user inputs the number of sheets to be recycled on the manual feed tray 24 or the like from the operation display unit 14, and subtracts the input number every time the erasing process is executed. The control unit 41 recognizes the remaining number. The input number and the remaining number are stored in the nonvolatile memory 44.

  When the remaining number of sheets requiring recycling at the time when the fixing possible temperature F is reached is M or less (step S313; Yes), the control unit 41 erases all the sheets requiring recycling that are present in the manual feed tray 24. The process is continued (steps S314; Yes, S315). When the erasure process for all the sheets requiring regeneration is completed (step S314; No), the process proceeds to step S302, and the next print job is executed.

  As described above, when the number of sheets of reclaimed paper remaining in an unerased state when the temperature of the fixing device 22 reaches the fixable temperature F is equal to or less than the predetermined number M, the start of the next print job is delayed. Since the erasing process for the remaining reclaimed paper is executed first, the erasing process can be completed in advance without waiting for the completion of the next print job (and other waiting jobs).

  The embodiment of the present invention has been described with reference to the drawings. However, the specific configuration is not limited to that shown in the embodiment, and there are changes and additions within the scope of the present invention. Are also included in the present invention.

  In the embodiment, the case where the end of the erasable period after the end of the print job is determined based on the elapsed time after the end of the job, the number of processed sheets in the erasing process after the end of the job, and the temperature of the fixing device 22 is exemplified. Which of these determination criteria is adopted may be configured to be switched by setting, or only one of the determination criteria may be configured.

  In the embodiment, the case where the reclaimed paper is transported from the manual feed tray 24 to the paper discharge destination via the image forming unit 21 and the fixing device 22 is shown. However, a paper feed tray and a transport path dedicated to the reclaimed paper are provided. May be. For example, a conveyance path may be provided in which paper is discharged from a paper feed tray dedicated for recycled paper through the fixing device 22 without going through the image forming unit 21.

  Further, in the embodiment, the case where the first paper discharge tray 25 and the second paper discharge tray 26 are provided is illustrated, but a configuration including more paper discharge destinations may be used. Further, it may be configured to have a discharge destination dedicated to erased recycled paper that is required.

  Further, FIG. 8 illustrates the case where the paper discharge destination is selected in the erasing process in the heating period, but the paper discharge destination is selected so that it does not overlap with the paper discharge destination related to the print job in the erasing process in the cooling period. It may be configured to. For example, a sensor for detecting the presence or absence of paper may be provided in each paper discharge tray, and control may be performed so that a paper discharge tray in which no paper is detected is selected as a paper discharge destination in the erasing process. Further, when there is no empty discharge tray, the erasing process in the cooling period may be stopped.

  In the erasing process in the cooling period, when the condition for determining the end of the erasing process is satisfied (when the temperature of the fixing device 22 decreases to the colorless temperature G, when a predetermined time after the job ends, or after the job ends) If the remaining number of reclaimed paper remaining on the manual feed tray 24 is equal to or less than N (for example, two) when the number of erased sheets reaches a predetermined number), the fixing unit 22 maintains the colorless temperature G. The erasing process for the remaining recycled paper may be continuously executed as it is. Also, if unerasable reclaimed paper remains when the conditions for determining the end of the erasure process are satisfied, the user is inquired whether or not to continue the erasure process, and the continuation instruction is received Alternatively, the erasing process may be continued by energizing the fixing device 22 so as to maintain the colorless temperature G.

  In the embodiment, the image forming apparatus 10 including the reading unit 11 is illustrated. However, the present invention may be any apparatus including the printer unit 20 having a fixing device, and an image reading function and the like are not essential.

1 is a cross-sectional view illustrating a configuration of an image forming apparatus according to an embodiment of the present invention. 1 is a block diagram showing an electrical configuration of an image forming apparatus according to an embodiment of the present invention. FIG. 6 is a characteristic diagram illustrating a temperature change of the fixing device when the image forming apparatus according to the embodiment of the present invention performs a print job. The printing-related operation in the case where the image forming apparatus according to the embodiment of the present invention performs an erasing process using an erasable period in the cooling period, and determines the end of the erasing process based on the elapsed time after the end of the job It is a flowchart which shows operation | movement in the case of doing. The printing-related operation in the case where the image forming apparatus according to the embodiment of the present invention performs an erasing process using the erasable period in the cooling period, and determines the end of the erasing process based on the number of processed sheets after the end of the job It is a flowchart which shows operation | movement in the case of doing. A printing-related operation in which the image forming apparatus according to the embodiment of the present invention performs an erasing process using an erasable period in the cooling period, and determines the end of the erasing process based on the temperature of the fixing device It is a flowchart which shows the operation | movement of. 5 is a flowchart showing a temperature raising process performed by the image forming apparatus according to the embodiment of the present invention. 10 is a flowchart showing a temperature raising process in a case where control is performed so that the paper discharge destination in the erasing process during the temperature rise does not overlap with the paper discharge destination of the printed matter related to the print job performed thereafter. FIG. 6 is a characteristic diagram illustrating an example of a temperature change of a fixing device when a next print job is input during an erasable period of a cooling period. 10 is a flowchart showing a print-related operation corresponding to a case where a next print job is input during execution of an erasing process in a cooling period. This is another example of the printing-related operation corresponding to the case where the next print job is submitted during the erasure processing in the cooling period, and shows the operation when the erasure processing is continued even after the next print job is submitted. It is a flowchart.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Image forming apparatus 11 ... Reading part 11a ... Line image sensor 12 ... Automatic document conveying apparatus 12a ... Document tray 14 ... Operation display part 20 ... Printer part 21 ... Image forming part 22 ... Fixing device 23 ... Paper feed tray 24 ... Manual feed Tray 25 ... first discharge tray 26 ... second discharge tray 27 ... conveying unit 28 ... temperature sensor 29 ... switching unit 31 ... photosensitive member 32 ... charging device 33 ... laser unit 34 ... developing device 35 ... transfer device 36 ... separation Device 37 ... Cleaning device 41 ... Control unit 42 ... Communication unit 43 ... Image storage unit 44 ... Non-volatile memory F ... Fixable temperature G ... Colorless temperature

Claims (10)

An image forming unit for forming a toner image on recording paper;
A fixing device that heats and fixes the toner image formed on the recording paper by the image forming unit to the recording paper;
A first transport unit that transports the recording paper stored in the first paper storage unit to a predetermined paper discharge destination via the image forming unit and the fixing device;
A second transport unit configured to transport a document including a portion drawn with a paint that becomes colorless when heated stored in the second paper storage unit to a predetermined discharge destination via the fixing unit;
Controls execution of a print job in which the recording paper stored in the first paper storage unit is transported to the first transport unit, and a toner image is formed on the recording paper by the image forming unit and fixed by the fixing device. At the same time, after the print job is finished, the document stored in the second sheet storage unit is transported to the second transport unit, and the paint drawn on the document is made colorless by the residual heat of the fixing device. A control unit for performing an erasing process, and
An image forming apparatus comprising: A temperature sensor for detecting the temperature of the fixing device is provided,
The image forming apparatus according to claim 1, wherein after the print job ends, the erasing process is ended when the temperature detected by the temperature sensor becomes lower than a predetermined temperature. The image forming apparatus according to claim 1, wherein the control unit ends the erasing process when a predetermined time elapses after the print job ends. The image forming apparatus according to claim 1, wherein after the print job is completed, the control unit terminates the erasing process when a predetermined number of sheets are applied. 5. The control unit according to claim 1, wherein when the next print job is input during execution of the erasure process after the print job is finished, the control unit stops the erasure process. 6. The image forming apparatus described in 1. 6. The control unit according to claim 1, wherein if the next print job has already been input at the end of the print job, the control unit starts execution of the next print job without performing the erasing process. The image forming apparatus according to any one of the above. The control unit further supplies the document stored in the second sheet storage unit to the second transport unit while raising the temperature of the fixing unit to a predetermined fixing possible temperature in preparation for starting a print job. The image forming apparatus according to claim 1, wherein an erasing process is performed in which the paint drawn on the document is colorless by heat of the fixing unit. The control unit delays the start of the print job when the number of documents stored in the second sheet storage unit is equal to or less than a predetermined number when the temperature of the fixing unit reaches the fixable temperature. The image forming apparatus according to claim 7, wherein the erasing process is continued until there is no document stored in the second sheet storage unit. A plurality of paper discharge trays used for switching between a paper discharge destination of the first transport unit and a paper discharge destination of the second transport unit;
8. The control unit according to claim 7, wherein the erasing process at the time of the temperature rise is performed by selecting a paper discharge tray that is not designated as a paper discharge destination of a waiting print job as a paper discharge destination. The image forming apparatus according to any one of 8. 10. The control unit according to claim 9, wherein the controller does not perform the erasing process at the time of the temperature rise if there is no discharge tray not designated as a discharge destination of a waiting print job. Image forming apparatus.

Images