JP2008310083A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem in that for a multi-color image forming apparatus, predetermined warming up processing is required, and much time is taken and idle rotation of a photoreceptor is made each time this process is performed, resulting in a decrease in the life time of the apparatus. <P>SOLUTION: The image forming apparatus having a door opening/closing sensor for detecting the opening/closing of a door is provided with a detecting means for monitoring the draw or insertion of a consumable article in a state of opening the door through which the consumable article can be drawn or inserted. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine or a printer using electrophotographic technology, and particularly to an image forming apparatus provided with consumables.

  An image forming apparatus that can be applied to a color printer, a color copying machine, a color facsimile, and the like will be described. The image forming apparatus has a plurality of developing units containing toners of different colors, and the plurality of developing units are sequentially arranged so that the toner adheres to the surface of the photosensitive belt. After the surface of the photosensitive belt is uniformly charged by a charger, the photosensitive belt is irradiated with laser light from an exposure device, and an electrostatic latent image corresponding to an image signal is formed. The electrostatic latent image formed on the surface of the photoreceptor belt is visualized as a toner image by the developing device and transferred to the intermediate transfer belt. The toner image transferred to the intermediate transfer belt is transferred to a sheet, and the toner image transferred to the sheet is fixed on the sheet by a fixing device, so that a multicolor image is printed.

JP 2000-330426 A

  In the above-described image forming apparatus, in order to control the standby state before printing, it is necessary to perform a predetermined warm-up process when the power is turned on, when the power saving mode is restored, when the door is opened / closed, or after the jam process. Since the photosensitive belt is idled at each processing, the photosensitive belt is worn due to friction with the cleaning blade and the developing device roller due to the idle rotation, and there is a problem that the life of the photosensitive belt is shortened. In addition, there is a toner density check process in the warm-up process, which wastes toner.

  FIG. 11 is a flowchart for explaining a conventional warm-up process.

  When the power is turned on, when the power saving mode is restored, when the door is opened and closed, and after jamming, first, the main motor, which is the power source of the photosensitive belt and transfer belt, is started, each actuator is operated, and the actuator is checked. Perform (step 901).

  In step 902, the developing motor is activated to check whether or not the developing device is mounted, and it is checked whether or not the developing device is mounted. At the same time, the key attached to the developing device is checked to determine whether the attached developing device is an illegal developing device.

  In step 903, the remaining amount of developer in the developing device is checked by the developing device detection mechanism. There is a hole through which the sensor light can pass near the developing roller of the developing device, and the remaining amount of the developing device is detected based on whether the sensor light passes or is blocked.

  In step 904, the speed of the main motor, which is a driving source for the photosensitive belt and the transfer belt, is adjusted. Further, toner is attached to the transfer belt, and the attached toner is read by a density sensor. The current toner density state is discriminated based on the read sensor level, and the toner density is adjusted by changing the latent image process and the voltage applied to each unit.

  Finally, the transfer belt cleaner is brought into contact with the transfer belt to clean the toner adhering to the transfer belt when adjusting the toner density, and the warm-up process is completed (step 905).

Therefore, in the past,
(1) When the door is opened as described above, all the power is turned off. Therefore, even if the consumables are not replaced, the initialization sequence is performed from the beginning after the door is closed, which takes time. .
(2) The door is opened for a certain period of time and the consumable replacement is considered due to the change in the sensor output, the initialization sequence is started, the door is closed within a certain period of time, and the consumable replacement is not determined. The initialization sequence was not performed. The time monitoring is used for grasping the temperature state of the fixing device, but the time monitoring is ambiguous for grasping the state such as a temperature change due to the use environment of the apparatus. For example, when the apparatus is used in a high temperature and high humidity environment and when it is used in a low temperature and low humidity environment, the temperature change of the fixing device cannot be grasped only by time.

  An object of the present invention is to solve the above-mentioned problems, and it reduces the idling time of the photosensitive belt and realizes a longer life of the photosensitive belt. It is another object of the present invention to provide an image forming apparatus that can reduce waste of toner associated with warm-up processing.

  The present invention that achieves the above object provides an image forming apparatus having a door opening / closing sensor for detecting a door opening / closing state, and detecting means for monitoring the state of the consumable supply / removal while the door is openable. It is characterized by having.

  According to the present invention, the developing device check, the toner presence check, the toner density check, the speed adjustment of the main motor that is a driving source of the photosensitive belt and the transfer belt, etc. are not performed every time the door is opened / closed so that consumables can be inserted and removed. The idling time of the belt can be reduced and the life of the photosensitive belt can be extended. Furthermore, toner waste can be reduced and warm-up time can be shortened.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of the entire image forming apparatus according to the embodiment, and FIG. 2 is a block diagram of a control device used in the image forming apparatus.

  As shown in FIG. 1, a photosensitive belt 1 is uniformly charged by a charger 3 while being rotated around a driving roller 2 at a constant speed, and laser light emitted from an exposure device 4 according to an image signal of each color. The electrostatic latent images of the colors corresponding to the respective colors are sequentially formed by selecting the developing devices using the corresponding color developers of the four developing devices 5, 6, 7, and 8. The latent images are sequentially developed to form each color toner image.

  The respective color toner images on the surface of the photosensitive belt 1 are transferred onto the surface of the intermediate transfer unit 9 that rotates synchronously while being in contact with the surface of the photosensitive belt 1, and the color toner images and Become.

  The paper 11 that is a recording medium accumulated in the paper feed cassette 10 is extracted and conveyed by the paper feed roller 12 and sent to the registration roller 13, and the color toner image on the surface of the paper 11 and the intermediate transfer unit 9 is registered with the registration roller 13. Then, the sheet is fed toward the transfer roller 14 after being controlled so as to be aligned.

  A voltage is applied to the leading end of the paper 11 sent to the transfer roller 14 to detect the current value flowing through the paper 11. The type of the paper 11 is discriminated based on the detected current value, and the speed of the motor, which is a drive source for the paper 11 conveyance, is varied before the paper 11 is conveyed to the fixing device 15. Further, when the conveyance speed of the paper 11 is changed, the second transfer voltage to be applied is changed when the toner latent image on the transfer belt 16 is transferred to the paper 11.

  Thereafter, the paper 11 is pulled up so as not to act in the process of forming the toner images of the respective colors on the photosensitive belt 1 on the surface of the intermediate transfer unit 9. The paper 11 on which the color toner image has been transferred is sent out toward the fixing roller 17. The fixing roller 17 constitutes a part of the fixing device 15, and when the fed paper 11 passes through the fixing roller 17, the color toner image is thermally fixed on the surface of the paper 11. The sheet 11 on which the color toner image is thermally fixed is discharged onto a discharge tray 19 via a discharge roller 18.

  The transfer belt cleaner 20 cleans toner remaining on the surface of the transfer belt 16. The transfer belt cleaner 20 is pulled up so that the cleaning operation does not work in the process of repeatedly transferring the single color toner image to the surface of the intermediate transfer unit 9 to form the color toner image, and the completed color toner image is transferred to the paper 11. After that, it is pressed so as to act on the surface of the intermediate transfer unit 9.

<(Developer) When developing unit sensor is monitored>
An embodiment of the present invention will be described in detail with reference to FIG.

  The control device 100 controls each constituent unit described above according to an input signal from the operation panel 101 and an input signal from the information processing device 106 described later.

  In FIG. 2, the control device 100 is mainly composed of a central processing unit (hereinafter abbreviated as CPU) 102, a ROM 103 storing a control program for the CPU 102, and a work memory RAM 104 necessary for the CPU 102 to execute the control program. Configured.

  An input / output interface (I / F) 105 mediates that the CPU 102 communicates with the information processing device 106 such as the operation panel 101 or a personal computer. Print data generated by the information processing device 106 is sent to the exposure control unit 107. introduce. The exposure control unit 107 controls the exposure apparatus 4 to generate laser light.

  The mechanism control unit 109 is a control unit group for controlling a group of mechanisms in the image forming process, and is controlled by the CPU 102 to control the motor unit 110, the developing unit 111, the cleaner unit 112, the charging unit 113, the transfer unit 114, and the fixing unit. Input / output of signals for controlling the unit 115 and the like.

  The motor control unit 116 is connected to control the motor 117 that drives the photosensitive belt 1, the paper feed roller 12, the registration roller 13, the fixing device 15, and the like, and a motor drive instruction signal S <b> 1 given from the motor unit 110. The drive signal S2 is output in accordance with the control signal S2 and the detection signal S3 for detecting the amount of angular displacement generated from the encoder 118 directly connected to the rotating shaft of the motor 117 is input. Further, the motor control unit 116 transmits the detection signal S3 from the encoder 118 to the CPU 102 via the interrupt control unit 119 as the rotation angle signal S4 of the photosensitive belt 1.

  Developer state detection processing in the image forming apparatus having the above-described configuration will be described with reference to the flowchart of FIG.

  The image forming apparatus performs a warm-up process when the power is turned on or after the door is opened / closed, after the jam process, until the printer is ready for printing. In the present invention, a series of warm-up processing operations in opening and closing the door will be described.

  First, after a door that allows the developer to be inserted and removed is opened, it is checked whether the developer has been removed or inserted (step 201). The door is, for example, behind the developing device opposite to the photosensitive belt 1 side. In step 201, it is detected from the detection signals of the developing device presence / absence sensors 21a to 21d that check the presence / absence of the developing device, whether the developing device has been inserted or removed. When a signal capable of determining that the developing device has been inserted / removed is detected, information on the removed developing device is stored. When a signal that can be determined that the developing device is not inserted / removed is detected, only the speed adjustment of the main motor that is a driving source of the photosensitive belt 1 and the transfer belt 16 is performed after the door that can be inserted / removed is closed. To complete the warm-up process.

  Next, after a door capable of inserting and removing the developing device is closed, a warm-up processing operation is performed (step 202). In the warm-up operation, first, a main motor that is a power source for the photosensitive belt 1 and the transfer belt 16 is activated to operate each actuator.

  In step 203, a developing motor is activated to check whether the developing device is attached, and it is checked whether the developing device is attached. At the same time, the key attached to the developing device is checked to determine whether the attached developing device is an illegal developing device.

  In step 204, the developing device detection mechanism checks the remaining amount of developer in the developing device. There is a hole through which the sensor light can pass in the vicinity of the developing roller of the developing device, and the remaining amount of the developer is detected based on whether the sensor light passes or is blocked.

  In step 205, the speed of the main motor, which is a drive source for the photosensitive belt 1 and the transfer belt 16, is adjusted. In addition, a latent image of toner is formed on the transfer belt 16, and the latent image is read by a density sensor. The current toner density state is discriminated based on the read sensor level, and the toner density is adjusted by changing the latent image process and the voltage applied to each unit.

  Based on the information obtained in step 201, steps 203, 204, and 205 are executed only for the developed color developer.

  Finally, the transfer belt cleaner 20 is brought into contact with the transfer belt 16 to clean the toner image formed on the transfer belt 16 when adjusting the toner density, and the warm-up process is completed (step 206).

  As described above, when the door to which the developing device can be inserted / removed is opened, a change in the state of the developing device presence / absence sensors 21a to 21d is grasped, and when the state changes, it is determined that the developing device has been removed and warming up is performed. During processing, a developer presence / absence check, toner presence / absence check, and toner density check are executed. Conversely, when the states of the developer presence / absence sensors 21a to 21d do not change, it is determined that the developer has not been removed, and the developer presence / absence check, toner presence / absence check, and toner density check are not performed during the warm-up process.

  By this control, the developer unit check, the toner presence check and the toner concentration check are not executed every time the door is opened and closed where the developer can be inserted and removed, so that the idling time of the photosensitive belt 1 is reduced and the life of the photosensitive belt 1 is shortened. Can be extended. Further, toner waste can be reduced and warm-up time can be shortened.

<(Developer) When toner presence sensor is monitored>
An embodiment of the present invention will be described in detail with reference to FIG.

  The control device 100 controls each constituent unit described above according to an input signal from the operation panel 101 and an input signal from an information processing device described later.

  In FIG. 2, the control device 100 is mainly composed of a central processing unit (hereinafter abbreviated as CPU) 102, a ROM 103 storing a control program for the CPU 102, and a work memory RAM 104 necessary for the CPU 102 to execute the control program. Configured.

  An input / output interface (I / F) 105 mediates communication of the CPU with the information processing device 106 such as the operation panel 101 or a personal computer, and print data generated by the information processing device 106 is sent to the exposure control unit 107. introduce. The exposure control unit 107 controls the exposure apparatus 4 to generate laser light.

  The mechanism control unit 109 is a control unit group for controlling a group of mechanisms in the image forming process, and is controlled by the CPU 102 to control the motor unit 110, the developing unit 111, the cleaner unit 112, the charging unit 113, the transfer unit 114, and the fixing unit. Input / output of signals for controlling the unit 115 and the like.

  The motor control unit 116 is connected to control the motor 117 that drives the photosensitive belt 1, the paper feed roller 12, the registration roller 13, the fixing device 15, and the like, and a motor drive instruction signal S <b> 1 given from the motor unit 110. The drive signal S2 is output in accordance with the control signal S2 and the detection signal S3 for detecting the amount of angular displacement generated from the encoder 118 directly connected to the rotating shaft of the motor 117 is input. Further, the motor control unit 116 transmits the detection signal S3 from the encoder 118 to the CPU 102 via the interrupt control unit 119 as the rotation angle signal S4 of the photosensitive belt 1.

  Developer state detection processing in the image forming apparatus having the above-described configuration will be described with reference to the flowchart of FIG.

  The image forming apparatus performs a warm-up process when the power is turned on or after the door is opened / closed, after the jam process, until the printer is ready for printing. In the present invention, a series of warm-up processing operations in opening and closing the door will be described.

  First, after a door that allows the developer to be inserted and removed is opened, it is checked whether the developer has been removed or inserted (step 211). In step 211, it is detected whether the developing unit has been inserted or removed from the detection signal of the toner presence / absence sensor that checks the state of the remaining amount of toner. When a signal capable of determining that the developing device has been inserted / removed is detected, information on the removed developing device is stored. When a signal that can be determined that the developing device is not inserted / removed is detected, the speed of the main motor that is a driving source of the photosensitive belt 1 and the transfer belt 16 is closed after the door that allows the developing device to be inserted / removed is closed. Only the adjustment is performed, and the warm-up process is terminated.

  Next, after a door capable of inserting and removing the developing device is closed, a warm-up processing operation is performed (step 212). In the warm-up operation, first, a main motor that is a power source for the photosensitive belt 1 and the transfer belt 16 is activated to operate each actuator.

  In step 213, the developing motor is activated to check whether or not the developing device is mounted, and it is checked whether or not the developing device is mounted. At the same time, the key attached to the developing device is checked to determine whether the attached developing device is an illegal developing device.

  In step 214, the developing device detection mechanism checks the remaining amount of developer in the developing device. There is a hole through which the sensor light can pass in the vicinity of the developing roller of the developing device, and the remaining amount of the developer is detected based on whether the sensor light passes or is blocked.

  In step 215, the speed of the main motor, which is a driving source for the photosensitive belt 1 and the transfer belt 16, is adjusted. In addition, a latent image of toner is formed on the transfer belt 16, and the latent image is read by a density sensor. The current toner density state is discriminated based on the read sensor level, and the toner density is adjusted by changing the latent image process and the voltage applied to each unit.

  Based on the information obtained in step 211, steps 213, 214 and 215 are executed only for the developed color developer.

  Finally, the transfer belt cleaner is brought into contact with the transfer belt to clean the toner image formed on the transfer belt when adjusting the toner density, and the warm-up process is completed (step 216).

  Here, an example of sensing by the toner presence / absence sensor is shown in FIG.

  Conventionally, it is used as a developer remaining amount check when the door is closed. The developer remaining amount check is made based on whether the output of the door open / close sensor is closed and the output signal of the toner presence / absence sensor. The output signal is provided with a toner empty detection range, and if the output signal is within the range, it is determined that there is toner. If the output signal is not within the range, it is determined that there is no toner.

  At the time of checking the insertion / extraction of the developing device, it is determined that the output of the door open / close sensor is the door open and the output signals of the toner presence / absence sensors 22a to 22d. When the output signals from the toner presence / absence sensors 22a to 22d are sensed and an output signal that can determine that there is no developing device is detected, it is determined that the developing device has been replaced. As the level of the output signal, a level different from the developer remaining amount check is used. Since an existing sensor is used, it can be used by changing only the control means without adding parts.

  As described above, when the door where the developing device can be inserted and removed is opened, a change in the state of the toner presence / absence sensors 22a to 22d is grasped, and when the state changes, it is determined that the developing device has been removed, and the warm-up process is performed. Sometimes the developer presence / absence check, toner presence / absence check and toner density check are executed. Conversely, when the state of the toner presence / absence sensors 22a to 22d does not change, it is determined that the developing unit has not been removed, and the developing unit presence / absence check, toner presence / absence check, and toner density check are not executed during the warm-up process.

  By this control, the developing device check, the toner presence check, and the toner density check are not executed every time the door is opened and closed where the developing device can be inserted and removed, so that the idle time of the photosensitive belt is reduced and the life of the photosensitive belt 1 is extended. be able to. Further, toner waste can be reduced and warm-up time can be shortened.

<(Waste toner bottle) When waste toner sensor is monitored>
An embodiment of the present invention will be described in detail with reference to FIG.

  The control device 100 controls each constituent unit described above according to an input signal from the operation panel 101 and an input signal from an information processing device described later.

  In FIG. 2, the control device 100 is mainly composed of a central processing unit (hereinafter abbreviated as CPU) 102, a ROM 103 storing a control program for the CPU 102, and a work memory RAM 104 necessary for the CPU 102 to execute the control program. Configured.

  An input / output interface (I / F) 105 mediates communication of the CPU with the information processing device 106 such as the operation panel 101 or a personal computer, and print data generated by the information processing device 106 is sent to the exposure control unit 107. introduce. The exposure control unit 107 controls the exposure apparatus 108 to generate laser light.

  The mechanism control unit 109 is a control unit group for controlling a group of mechanisms in the image forming process, and is controlled by the CPU 102 to control the motor unit 110, the developing unit 111, the cleaner unit 112, the charging unit 113, the transfer unit 114, and the fixing unit. Input / output of signals for controlling the unit 115 and the like.

  The motor control unit 116 is connected to control the motor 117 that drives the photosensitive belt 1, the paper feed roller 12, the registration roller 13, the fixing device 15, and the like, and a motor drive instruction signal S <b> 1 given from the motor unit 110. The drive signal S2 is output in accordance with the control signal S2 and the detection signal S3 for detecting the amount of angular displacement generated from the encoder 118 directly connected to the rotating shaft of the motor 117 is input. Further, the motor control unit 116 transmits the detection signal S3 from the encoder 118 to the CPU 102 via the interrupt control unit 119 as the rotation angle signal S4 of the photosensitive belt 1.

  The waste toner bottle state detection process in the image forming apparatus having the above-described configuration will be described with reference to the flowchart of FIG.

  The image forming apparatus performs a warm-up process when the power is turned on or after the door is opened / closed, after the jam process, until the printer is ready for printing. In the present invention, a series of warm-up processing operations in opening and closing the door will be described.

  First, after a door that allows the waste toner bottle 29 to be inserted and removed is opened, it is checked whether the waste toner bottle 29 has been removed or inserted (step 301). In step 301, it is detected whether the waste toner bottle 29 has been inserted or removed from the detection signal of the waste toner sensor 23 that checks the presence / absence of the waste toner bottle 29. When a signal capable of determining that the waste toner bottle 29 has been removed / inserted is detected, information on the removed / removed waste toner bottle is stored. When a signal that can be determined that the waste toner bottle 29 is not inserted / removed is detected, a main motor that is a drive source for the photosensitive belt and the transfer belt after the door that allows the waste toner bottle 29 to be inserted / removed is closed. Only the speed adjustment is performed, and the warm-up process is terminated.

  Next, after the door capable of inserting and removing the waste toner bottle 29 is closed, a warm-up processing operation is performed (step 302). In the warm-up operation, first, a main motor that is a power source for the photosensitive belt 1 and the transfer belt 16 is activated to operate each actuator.

  In step 303, it is checked whether the waste toner bottle 29 is attached. Also, the amount of waste toner in the waste toner bottle 9 is checked by the waste toner sensor 23.

  Finally, the speed of the main motor, which is a drive source for the photosensitive belt 1 and the transfer belt 16, is adjusted, and the warm-up process is finished (step 304).

  An example of sensing by the waste toner sensor 23 is shown in FIG.

  Conventionally, when the door is closed, it is used as a waste toner bottle full check. The waste toner bottle full check is performed based on whether the output of the door opening / closing sensor is closed and the output signal of the waste toner sensor. The output signal is provided with a detection range where there is a waste toner bottle, and if the output signal is within that range, it is determined that the waste toner bottle 29 is present and the waste toner bottle 29 is not full. If the output signal is not within the range, it is determined by the output signal that the waste toner bottle is full or there is no waste toner bottle.

  At the time of checking the removal / insertion of the waste toner bottle, it is determined that the output of the door open / close sensor is the door open and the output signal of the waste toner sensor. When the output signal of the waste toner bottle sensor is sensed and an output signal that can be determined to be no waste toner bottle 29 is detected, it is determined that the waste toner bottle 29 has been replaced. The level of the output signal is different from that used when the waste toner bottle is full. Since an existing sensor is used, it can be used by changing only the control means without adding parts.

  In this way, when the door where the waste toner bottle 29 can be inserted and removed is opened, the change in the state of the waste toner sensor is grasped, and when the state changes, it is determined that the waste toner bottle has been removed, and during the warm-up process A waste toner bottle mounting check and a waste toner amount check are executed. Conversely, when the state of the waste toner sensor does not change, it is determined that the waste toner bottle 29 has not been removed, and the waste toner bottle attachment check and the waste toner amount check are not performed during the warm-up process.

  By this control, the developer unit check, toner presence check and toner density check are not executed every time the door is opened and closed so that the waste toner bottle 29 can be inserted / removed, thereby reducing the idling time of the photosensitive belt and extending the life of the photosensitive belt. Can be extended. Further, toner waste can be reduced and warm-up time can be shortened.

  The door through which the waste toner bottle 29 can be inserted and removed can be provided in any vicinity of the waste toner bottle 29.

<(Photosensitive belt) When the photosensitive belt marker sensor is monitored>
An embodiment of the present invention will be described in detail with reference to FIG.

  The control device 100 controls each constituent unit described above according to an input signal from the operation panel 101 and an input signal from an information processing device described later.

  In FIG. 2, the control device 100 is mainly composed of a central processing unit (hereinafter abbreviated as CPU) 102, a ROM 103 storing a control program for the CPU 102, and a work memory RAM 104 necessary for the CPU 102 to execute the control program. Configured.

  An input / output interface (I / F) 105 mediates communication of the CPU with the information processing device 106 such as the operation panel 101 or a personal computer, and print data generated by the information processing device 106 is sent to the exposure control unit 107. introduce. The exposure control unit 107 controls the exposure apparatus 108 to generate laser light.

  The mechanism control unit 109 is a control unit group for controlling a group of mechanisms in the image forming process, and is controlled by the CPU 102 to control the motor unit 110, the developing unit 111, the cleaner unit 112, the charging unit 113, the transfer unit 114, and the fixing unit. Input / output of signals for controlling the unit 115 and the like.

  The motor control unit 116 is connected to control the motor 117 that drives the photosensitive belt 1, the paper feed roller 12, the registration roller 13, the fixing device 15, and the like, and a motor drive instruction signal S <b> 1 given from the motor unit 110. The drive signal S2 is output in accordance with the control signal S2 and the detection signal S3 for detecting the amount of angular displacement generated from the encoder 118 directly connected to the rotating shaft of the motor 117 is input. Further, the motor control unit 116 transmits the detection signal S3 from the encoder 118 to the CPU 102 via the interrupt control unit 119 as the rotation angle signal S4 of the photosensitive belt 1.

  Photoconductor belt state detection processing in the image forming apparatus having the above-described configuration will be described with reference to the flowchart of FIG.

  The image forming apparatus performs a warm-up process when the power is turned on or after the door is opened / closed, after the jam process, until the printer is ready for printing. In the present invention, a series of warm-up processing operations in opening and closing the door will be described.

  First, after a door that allows the photosensitive belt to be inserted and removed is opened, it is checked whether the photosensitive belt has been inserted and removed (step 401). In step 401, it is detected whether the photosensitive belt 1 has been inserted or removed from the detection signal of the photosensitive belt marker sensor 24 for checking the marker of the photosensitive belt 1. When a signal capable of determining that the photosensitive belt 1 has been inserted / removed is detected, information on the inserted / removed photosensitive belt 1 is stored. If a signal that can be determined that the photosensitive belt 1 is not inserted / removed is detected, the warm-up process ends after the door that allows the photosensitive belt 1 to be inserted / removed is closed. The photoreceptor belt 1 can also be inserted and removed from the door above the apparatus.

  Next, after the door on which the photosensitive belt 1 can be inserted and removed is closed, a warm-up processing operation is performed (step 402). In the warm-up operation, first, a main motor that is a power source of the photosensitive belt and the transfer belt is activated, and each actuator is operated.

  In step 403, the developing motor is activated to check whether the photosensitive belt is attached, and it is checked whether the photosensitive belt 1 is attached.

  In step 404, the speed of the main motor that is the driving source of the photosensitive belt 1 and the transfer belt 16 is adjusted. In addition, a latent image of toner is formed on the transfer belt 16, and the latent image is read by a density sensor. The current toner density state is discriminated based on the read sensor level, and the toner density is adjusted by changing the latent image process and the voltage applied to each unit.

  Finally, a transfer belt cleaner is brought into contact with the transfer belt 16 to clean the toner imaged on the transfer belt at the time of toner density adjustment, and the warm-up process is completed (step 405).

  In this way, when the door where the photosensitive belt can be inserted and removed is opened, the change in the state of the photosensitive belt marker sensor 24 is grasped, and when the state changes, it is determined that the photosensitive belt has been removed, During the warm-up process, a photoreceptor belt mounting check, main motor speed adjustment, and toner density check are executed. Conversely, when the state of the photosensitive belt marker sensor 24 does not change, it is determined that the photosensitive belt 1 has not been pulled out, and the photosensitive belt mounting check, main motor speed adjustment, and toner density check are not performed during the warm-up process.

  By this control, the developing device check, the toner presence check and the toner density check are not executed every time the door is opened and closed where the photoreceptor belt 1 can be inserted and removed, thereby reducing the idling time of the photoreceptor belt and the life of the photoreceptor belt 1. Can be extended. Further, toner waste can be reduced and warm-up time can be shortened.

<When the (transfer belt cleaner) cleaner sensor is monitored>
An embodiment of the present invention will be described in detail with reference to FIG.

  The control device 100 controls each constituent unit described above according to an input signal from the operation panel 101 and an input signal from an information processing device described later.

  In FIG. 2, the control device 100 is mainly composed of a central processing unit (hereinafter abbreviated as CPU) 102, a ROM 103 storing a control program for the CPU 102, and a work memory RAM 104 necessary for the CPU 102 to execute the control program. Configured.

  An input / output interface (I / F) 105 mediates communication of the CPU with the information processing device 106 such as the operation panel 101 or a personal computer, and print data generated by the information processing device 106 is sent to the exposure control unit 107. introduce. The exposure control unit 107 controls the exposure apparatus 108 to generate laser light.

  The mechanism control unit 109 is a control unit group for controlling a group of mechanisms in the image forming process, and is controlled by the CPU 102 to control the motor unit 110, the developing unit 111, the cleaner unit 112, the charging unit 113, the transfer unit 114, and the fixing unit. Input / output of signals for controlling the unit 115 and the like.

  The motor control unit 116 is connected to control the motor 117 that drives the photosensitive belt 1, the paper feed roller 12, the registration roller 13, the fixing device 15, and the like, and a motor drive instruction signal S <b> 1 given from the motor unit 110. The drive signal S2 is output in accordance with the control signal S2, and the detection signal S3 for detecting the angular displacement amount generated from the encoder 118 directly connected to the rotating shaft of the motor 117 is input. Further, the motor control unit 116 transmits the detection signal S3 from the encoder 118 to the CPU 102 via the interrupt control unit 119 as the rotation angle signal S4 of the photosensitive belt 1.

  The transfer belt cleaner state detection process in the image forming apparatus having the above-described configuration will be described with reference to the flowchart of FIG.

  The image forming apparatus performs a warm-up process when the power is turned on or after the door is opened / closed, after the jam process, until the printer is ready for printing. In the present invention, a series of warm-up processing operations in opening and closing the door will be described.

  First, after a door that allows the transfer belt cleaner 20 to be inserted and removed is opened, it is checked whether the transfer belt cleaner 20 has been inserted or removed (step 501). In step 501, it is detected whether the transfer belt cleaner 20 has been inserted or removed from a detection signal of a cleaner sensor that checks for the presence or absence of the transfer belt cleaner. When a signal capable of determining that the transfer belt cleaner 20 has been inserted / removed is detected, information on the transferred belt cleaner 20 that has been removed / inserted is stored. If a signal that can be determined that the transfer belt cleaner 20 is not inserted / removed is detected, the warm-up process ends after the door that allows the transfer belt cleaner 20 to be inserted / removed is closed.

  Next, after the door on which the transfer belt cleaner 20 can be inserted and removed is closed, a warm-up processing operation is performed (step 502). In the warm-up operation, first, a main motor that is a power source for the photosensitive belt 1 and the transfer belt 16 is activated to operate each actuator.

  In step 503, it is checked whether the transfer belt cleaner 20 is attached.

  In step 504, the speed of the main motor, which is a drive source for the photosensitive belt and the transfer belt, is adjusted. In addition, a latent image of toner is formed on the transfer belt 16, and the latent image is read by a density sensor. The current toner density state is discriminated based on the read sensor level, and the toner density is adjusted by changing the latent image process and the voltage applied to each unit.

  Finally, the transfer belt cleaner 20 is brought into contact with the transfer belt 16 to clean the toner formed on the transfer belt 16 at the time of toner density adjustment, and the warm-up process is completed (step 505).

  As described above, when the door where the transfer belt cleaner 20 can be inserted and removed is opened, the change in the state of the transfer belt cleaner sensor 25 is grasped, and when the state changes, it is determined that the transfer belt cleaner is removed, During the warm-up process, a transfer belt cleaner installation check, main motor speed adjustment and toner density check are executed. Conversely, when the state of the transfer belt cleaner sensor 25 does not change, it is determined that the transfer belt cleaner 20 has not been removed, and the transfer belt cleaner mounting check, main motor speed adjustment, and toner density check are not performed during the warm-up process. The transfer belt cleaner 20 can also be inserted and removed from the door above the apparatus.

  By this control, the developer belt check, the toner presence check and the toner density check are not executed every time the door is opened and closed where the transfer belt cleaner 20 can be inserted and removed, so that the idling time of the photosensitive belt 1 is reduced and the photosensitive belt 1 Life can be extended. Further, toner waste can be reduced and warm-up time can be shortened.

<(Transfer belt) When the transfer belt marker sensor is monitored>
An embodiment of the present invention will be described in detail with reference to FIG.

  The control device 100 controls each constituent unit described above according to an input signal from the operation panel 101 and an input signal from an information processing device described later.

  In FIG. 2, the control device 100 is mainly composed of a central processing unit (hereinafter abbreviated as CPU) 102, a ROM 103 storing a control program for the CPU 102, and a work memory RAM 104 necessary for the CPU 102 to execute the control program. Configured.

  An input / output interface (I / F) 105 mediates communication of the CPU with the information processing device 106 such as the operation panel 101 or a personal computer, and print data generated by the information processing device 106 is sent to the exposure control unit 107. introduce. The exposure control unit 107 controls the exposure apparatus 108 to generate laser light.

  The mechanism control unit 109 is a control unit group for controlling a group of mechanisms in the image forming process, and is controlled by the CPU 102 to control the motor unit 110, the developing unit 111, the cleaner unit 112, the charging unit 113, the transfer unit 114, and the fixing unit. Input / output of signals for controlling the unit 115 and the like.

  The motor control unit 116 is connected to control the motor 117 that drives the photosensitive belt 1, the paper feed roller 12, the registration roller 13, the fixing device 15, and the like, and a motor drive instruction signal S <b> 1 given from the motor unit 110. The drive signal S2 is output in accordance with the control signal S2 and the detection signal S3 for detecting the amount of angular displacement generated from the encoder 118 directly connected to the rotating shaft of the motor 117 is input. Further, the motor control unit 116 transmits the detection signal S3 from the encoder 118 to the CPU 102 via the interrupt control unit 119 as the rotation angle signal S4 of the photosensitive belt 1.

  The transfer belt marker state detection process in the image forming apparatus having the above-described configuration will be described with reference to the flowchart of FIG.

  The image forming apparatus performs a warm-up process when the power is turned on or after the door is opened / closed, after the jam process, until the printer is ready for printing. In the present invention, a series of warm-up processing operations in opening and closing the door will be described.

  First, after a door that allows the transfer belt 16 to be inserted and removed is opened, it is checked whether the transfer belt has been inserted or removed (step 601). In step 601, it is detected from the detection signal of the transfer belt marker sensor 26 that checks the rotational speed of the transfer belt 16 whether the transfer belt has been inserted or removed. When a signal capable of determining that the transfer belt has been inserted / removed is detected, information on the removed / inserted transfer belt is stored. If a signal that can be determined that the transfer belt is not inserted / removed is detected, the warm-up process ends after the door that allows the transfer belt to be inserted / removed is closed.

  Next, after the door on which the transfer belt 16 can be inserted and removed is closed, a warm-up processing operation is performed (step 602). In the warm-up operation, first, a main motor that is a power source of the photosensitive belt and the transfer belt is activated, and each actuator is operated.

  In step 603, the developing motor is activated to check whether or not the transfer belt 16 is mounted, and it is checked whether or not the transfer belt 16 is mounted.

  In step 604, the speed of the main motor, which is a driving source for the photosensitive belt 1 and the transfer belt 16, is adjusted. In addition, a latent image of toner is formed on the transfer belt 16, and the latent image is read by a density sensor. The current toner density state is discriminated based on the read sensor level, and the toner density is adjusted by changing the latent image process and the voltage applied to each unit.

  Finally, the transfer belt cleaner 20 is brought into contact with the transfer belt 16 to clean the toner image formed on the transfer belt when adjusting the toner density, and the warm-up process is completed (step 605).

  As described above, when the door where the transfer belt 16 can be inserted and removed is opened, the change in the state of the transfer belt marker sensor 26 is grasped, and when the state changes, it is determined that the transfer belt has been removed, and the warm-up process is performed. Occasionally, a transfer belt mounting check, main motor speed adjustment, and toner density check are performed. Conversely, when the state of the transfer belt marker sensor does not change, it is determined that the transfer belt has not been removed, and the transfer belt mounting check, main motor speed adjustment, and toner density check are not performed during the warm-up process.

  With this control, the developer belt check, toner presence check, and toner density check are not executed every time the door is opened or closed when the transfer belt can be inserted and removed, thereby reducing the idling time of the photosensitive belt and extending the life of the photosensitive belt. Can do. Further, toner waste can be reduced and warm-up time can be shortened.

<(Transfer roller) When the transfer roller sensor is monitored>
An embodiment of the present invention will be described in detail with reference to FIG.

  The control device 100 controls each constituent unit described above according to an input signal from the operation panel 101 and an input signal from an information processing device described later.

  In FIG. 2, the control device 100 is mainly composed of a central processing unit (hereinafter abbreviated as CPU) 102, a ROM 103 storing a control program for the CPU 102, and a work memory RAM 104 necessary for the CPU 102 to execute the control program. Configured.

  An input / output interface (I / F) 105 mediates communication of the CPU with the information processing device 106 such as the operation panel 101 or a personal computer, and print data generated by the information processing device 106 is sent to the exposure control unit 107. introduce. The exposure control unit 107 controls the exposure apparatus 108 to generate laser light.

  The mechanism control unit 109 is a control unit group for controlling a group of mechanisms in the image forming process, and is controlled by the CPU 102 to control the motor unit 110, the developing unit 111, the cleaner unit 112, the charging unit 113, the transfer unit 114, and the fixing unit. Input / output of signals for controlling the unit 115 and the like.

  The motor control unit 116 is connected to control the motor 117 that drives the photosensitive belt 1, the paper feed roller 12, the registration roller 13, the fixing device 15, and the like, and a motor drive instruction signal S <b> 1 given from the motor unit 110. The drive signal S2 is output in accordance with the control signal S2, and the detection signal S3 for detecting the angular displacement amount generated from the encoder 118 directly connected to the rotating shaft of the motor 117 is input. Further, the motor control unit 116 transmits the detection signal S3 from the encoder 118 to the CPU 102 via the interrupt control unit 119 as the rotation angle signal S4 of the photosensitive belt 1.

  The transfer roller state detection process in the image forming apparatus having the above-described configuration will be described with reference to the flowchart of FIG.

  The image forming apparatus performs a warm-up process when the power is turned on or after the door is opened / closed, after the jam process, until the printer is ready for printing. In the present invention, a series of warm-up processing operations in opening and closing the door will be described.

  First, after a door that allows the transfer roller 14 to be inserted and removed is opened, it is checked whether the transfer roller has been inserted or removed (step 701). In step 701, it is detected whether the transfer roller 14 has been inserted or removed from the detection signal of the transfer roller sensor 27 that checks the presence or absence of the transfer roller 14. When a signal capable of determining that the transfer roller has been inserted / removed is detected, information on the transferred transfer roller is stored. When a signal that can be determined that the transfer roller is not inserted / removed is detected, the warm-up process ends after the door that allows the transfer roller to be inserted / removed is closed.

  Next, after the door on which the transfer roller 14 can be inserted and removed is closed, a warm-up processing operation is performed (step 702). In the warm-up operation, first, a main motor that is a power source of the photosensitive belt and the transfer belt is activated, and each actuator is operated.

  In step 703, it is checked whether the transfer roller 14 is mounted.

  In step 704, the speed of the main motor, which is a drive source for the photosensitive belt and transfer belt, is adjusted. In addition, a latent image of toner is formed on the transfer belt, and the latent image is read by a density sensor. The current toner density state is discriminated based on the read sensor level, and the toner density is adjusted by changing the latent image process and the voltage applied to each unit.

  Finally, the transfer belt cleaner 20 is brought into contact with the transfer belt 16 to clean the toner image formed on the transfer belt at the time of toner density adjustment, and the warm-up process is completed (step 705).

  As described above, when the door on which the transfer roller 14 can be inserted and removed is opened, the change in the state of the transfer roller sensor is grasped, and when the state changes, it is determined that the transfer roller has been removed, and the transfer is performed during the warm-up process. Perform roller mounting check, main motor speed adjustment and toner density check. Conversely, when the state of the transfer roller sensor does not change, it is determined that the transfer roller has not been removed, and the transfer roller mounting check, main motor speed adjustment, and toner density check are not performed during the warm-up process. The door through which the transfer roller 14 can be inserted and removed is provided around the transfer roller 14, for example, on the side opposite to the transfer belt (left side in FIG. 1).

  This control does not perform a developer check, toner presence check, or toner density check every time the door is opened or closed when the transfer roller can be inserted and removed, thus reducing the idling time of the photoconductor belt and extending the life of the photoconductor belt. Can do. Further, toner waste can be reduced and warm-up time can be shortened.

<(Fixing unit) When the fixing unit presence / absence sensor is monitored>
An embodiment of the present invention will be described in detail with reference to FIG.

  The control device 100 controls each constituent unit described above according to an input signal from the operation panel 101 and an input signal from an information processing device described later.

  In FIG. 2, the control device 100 is mainly composed of a central processing unit (hereinafter abbreviated as CPU) 102, a ROM 103 storing a control program for the CPU 102, and a work memory RAM 104 necessary for the CPU 102 to execute the control program. Configured.

  An input / output interface (I / F) 105 mediates communication of the CPU with the information processing device 106 such as the operation panel 101 or a personal computer, and print data generated by the information processing device 106 is sent to the exposure control unit 107. introduce. The exposure control unit 107 controls the exposure apparatus 108 to generate laser light.

  The mechanism control unit 109 is a control unit group for controlling a group of mechanisms in the image forming process, and is controlled by the CPU 102 to control the motor unit 110, the developing unit 111, the cleaner unit 112, the charging unit 113, the transfer unit 114, and the fixing unit. Input / output of signals for controlling the unit 115 and the like.

  The motor control unit 116 is connected to control the motor 117 that drives the photosensitive belt 1, the paper feed roller 12, the registration roller 13, the fixing device 15, and the like, and a motor drive instruction signal S <b> 1 given from the motor unit 110. The drive signal S2 is output in accordance with the control signal S2, and the detection signal S3 for detecting the angular displacement amount generated from the encoder 118 directly connected to the rotating shaft of the motor 117 is input. Further, the motor control unit 116 transmits the detection signal S3 from the encoder 118 to the CPU 102 via the interrupt control unit 119 as the rotation angle signal S4 of the photosensitive belt 1.

  The fixing device state detection process in the image forming apparatus having the above-described configuration will be described with reference to the flowchart of FIG.

  The image forming apparatus performs a warm-up process when the power is turned on or after the door is opened / closed, after the jam process, until the printer is ready for printing. In the present invention, a series of warm-up processing operations in opening and closing the door will be described.

  First, after a door that allows the fixing device 15 to be inserted / removed is opened, it is checked whether the fixing device 15 has been inserted / removed (step 801). In step 801, it is detected whether or not the fixing device has been removed from the fixing device presence / absence sensor 28 for checking the presence or absence of the fixing device. When a signal capable of determining that the fixing device has been inserted / removed is detected, information on the removed fixing device 15 is stored. In addition, when a signal that can be determined that the fixing device 15 is not inserted / removed is detected, a predetermined fixing device warm-up process is performed based on temperature information from the thermistor after the door capable of inserting / removing the fixing device is closed. ,finish.

  Next, after the door capable of inserting and removing the fixing device is closed, a warm-up processing operation is performed (step 802). In the warm-up operation, first, a main motor that is a power source of the photosensitive belt and the transfer belt is activated, and each actuator is operated.

  In step 803, it is checked whether the fixing device 15 is installed.

  Finally, the speed of the main motor, which is a drive source for the photosensitive belt and the transfer belt, is adjusted, and a predetermined fixing unit warm-up process is performed. Thereafter, the warm-up process is terminated (step 804).

  In this way, when the door where the fixing device can be inserted and removed is opened, the change in the state of the fixing device presence / absence detection signal is grasped, and when the state changes, it is determined that the fixing device has been removed, and during the warm-up process Adjusts the speed of the main motor and warms up the fuser. Conversely, when the state of the fixing device presence / absence signal does not change, it is determined that the fixing device has not been removed, and the transfer belt attachment check, main motor speed adjustment, and toner density check are not performed during the warm-up process.

  By this control, the developer unit check, toner presence check and toner density check are not executed every time the door is opened and closed when the fixing unit can be inserted / removed, thereby reducing the idling time of the photosensitive belt and extending the life of the photosensitive belt. Can do. Further, toner waste can be reduced and warm-up time can be shortened.

  The feature of the present invention is that it grasps the change in the state of the sensor that detects the presence or absence of a consumable when the consumable pluggable door is open, and determines that the consumable has been removed when the state changes, warming up Initial processing required by removing and inserting consumables during processing is executed. Conversely, if the state of the sensor that detects the presence or absence of consumables does not change, it is determined that the consumables have not been removed, and the warm-up process requires initial warm-up processing and the initial processing required by inserting and removing consumables. Do not execute.

  In addition, if the embodiment of the present invention is used, the developer belt check, the toner presence check and the toner density check are not executed every time the door is opened and closed where consumables can be inserted and removed. The life of the body belt can be extended. Further, toner waste can be reduced and warm-up time can be shortened.

  A feature of the present invention is to provide an image forming apparatus that grasps a change in the state of a sensor that detects the insertion / removal of a consumable while the door to which the consumable can be inserted / removed is open, and switches the warm-up process according to the change in the state of the sensor There is. Eventually, it has the effect of reducing the idling time of the photosensitive belt of the image forming apparatus and extending the life of the photosensitive belt.

1 is a schematic configuration diagram of an entire image forming apparatus according to an embodiment of the present invention. 2 is a block diagram of a control device used in the image forming apparatus. FIG. It is a flowchart of a series of warm-up processing operations including a developing device state detection process. It is a flowchart of a series of warm-up processing operations including a developing device state detection process. 10 is a flowchart of a series of warm-up processing operations including waste toner bottle state detection processing. 6 is a flowchart of a series of warm-up processing operations including a photoreceptor belt state detection process. It is a flowchart of a series of warm-up processing operations including a transfer belt cleaner state detection process. 6 is a flowchart of a series of warm-up processing operations including a transfer belt state detection process. It is a flowchart of a series of warm-up process operations including a transfer roller state detection process. It is a flowchart of a series of warm-up processing operations including fixing device state detection processing. It is a flowchart of the conventional warm-up process operation after opening and closing the door from which consumables can be inserted and removed. 6 is a time chart of sensing of a developing device insertion / removal by a toner presence sensor. 6 is a time chart for sensing when a waste toner bottle is inserted and removed by a waste toner sensor.

Explanation of symbols

  1 photosensitive belt, 2 drive roller, 3 charger, 4 exposure device, 5-8 developing device, 9 intermediate transfer unit, 10 paper feed cassette, 11 paper, 12 paper feed roller, 13 registration roller, 14 transfer roller, 15 Fixing device, 16 transfer belt, 17 fixing roller, 18 paper discharge roller, 19 paper discharge tray, 20 transfer belt cleaner, 21a-d developer presence sensor, 22a-d toner presence sensor, 23 waste toner sensor, 24 photoreceptor belt Marker sensor, 25 cleaner sensor, 26 transfer belt marker sensor, 27 transfer roller sensor, 28 fixing device presence / absence sensor, 29 waste toner bottle.

Claims (11)

  An image forming apparatus having a door opening / closing sensor that detects a door opening / closing state, and having a developer, a developing device that contains the developer, and a detecting unit that detects the presence or absence of the developing device. A warming-up after opening / closing the developing unit's removable door with a detecting means for monitoring the state of the developing device's insertion / removal by a sensor that detects the presence / absence of the developing device with the removable door open An image forming apparatus comprising: detecting whether or not the developing unit has been inserted and removed before processing, and switching warm-up processing based on the detection result.   In an image forming apparatus having a door opening / closing sensor for detecting a door opening / closing state, and having a developer, a developer containing the developer, and a developer remaining amount detecting means for detecting a remaining amount of the developer. And a detecting means for monitoring a state of the developer being inserted and removed by a sensor for detecting a remaining amount of the developer in a state in which the door capable of inserting and removing the developer is opened. An image forming apparatus characterized by detecting whether or not the developing device has been inserted and removed before the warm-up process after opening and closing, and switching the warm-up process according to the detection result. The image forming apparatus according to claim 1 or 2,
An image forming apparatus, comprising: a detecting unit that monitors whether or not a plurality of the developing devices have been inserted and removed by the individual developing devices.   A door opening / closing sensor that detects a door open / close state, a developer, a developer that stores the developer, a waste toner bottle that stores waste toner, and a detection unit that detects the capacity of the waste toner bottle. An image forming apparatus comprising: a detecting unit that monitors a state of inserting / removing the waste toner bottle by a sensor that detects a capacity of the waste toner bottle in a state where the door capable of inserting / removing the waste toner bottle is opened; An image forming method comprising: detecting whether or not the waste toner bottle has been inserted / removed before the warm-up process after opening / closing the door capable of inserting / removing the waste toner bottle, and switching the warm-up process based on the detection result. apparatus.   An image forming apparatus having a door opening / closing sensor that detects a door opening / closing state, and having a developer, a developing device that accommodates the developer, a photosensitive belt, and a detecting unit that detects a joint of the photosensitive belt. And detecting means for monitoring the state of insertion / removal of the photoreceptor belt by a sensor for detecting a joint of the photoreceptor belt in a state in which the door to which the photoreceptor belt can be inserted / removed is opened, An image forming apparatus characterized by detecting whether or not the photosensitive belt has been inserted / removed before the warm-up process after opening / closing the removable door, and switching the warm-up process based on the detection result.   A door opening / closing sensor that detects a door opening / closing state; a photosensitive belt; a transfer belt; a transfer belt cleaner that cleans toner remaining on the transfer belt; and a detection unit that detects presence or absence of the transfer belt cleaner. An image forming apparatus comprising: a detecting unit that monitors a state of the transfer belt cleaner being inserted / removed by a sensor that detects the presence / absence of the transfer belt cleaner in a state where the door to which the transfer belt cleaner can be inserted / removed is opened; An image forming apparatus comprising: detecting whether or not the transfer belt cleaner has been inserted / removed before opening / closing the door to which the transfer belt cleaner can be inserted / removed, and switching the warm-up process based on the detection result.   In an image forming apparatus having a door opening / closing sensor for detecting a door opening / closing state, and having a photosensitive belt, a transfer belt, and a detecting means for detecting a rotation speed of the transfer belt, the door in which the transfer belt can be inserted and removed Warming-up after opening / closing the transfer belt door with a detecting means for monitoring the transfer belt insertion / removal state by means of a transfer belt marker sensor for detecting the rotation speed of the transfer belt in the open state An image forming apparatus characterized by detecting whether or not the transfer belt has been inserted and removed before processing, and switching warm-up processing based on the detection result.   In an image forming apparatus having a door opening / closing sensor for detecting a door opening / closing state, and having a transfer belt, a transfer roller, and a detecting means for detecting presence / absence of the transfer roller, the door in which the transfer roller can be inserted and removed Before the warming-up process after opening / closing the door that can be inserted / removed to / from the transfer roller by a transfer roller sensor that detects the presence / absence of the transfer roller in a state where the transfer roller is open. In addition, the image forming apparatus is characterized by detecting whether or not the transfer roller has been inserted and removed, and switching the warm-up process according to the detection result.   An image forming apparatus having a door opening / closing sensor for detecting a door opening / closing state, and having a fixing device and a detecting means for detecting the presence / absence of the fixing device, wherein the fixing device is openable / detachable. Detection means for detecting the presence / absence of the fixing device, and a detecting means for monitoring the state of insertion / removal of the fixing device, and before the warm-up process after opening / closing the removable door of the fixing device, An image forming apparatus characterized by detecting whether or not insertion / removal has been performed and switching a warm-up process according to the detection result.   The image forming apparatus according to claim 1, further comprising a detecting unit that monitors a state in which a consumable item is inserted or removed only by an output of the sensor.   5. The image forming apparatus according to claim 2, further comprising a warm-up process switching control unit according to an output level of an existing sensor.

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