JP7275866B2 - Image forming apparatus and program - Google Patents

Description

The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile machine, or a multifunction machine having these functions, which forms an image by an electrophotographic process, and a program.

An image forming apparatus for forming an image by an electrophotographic process as described above is provided with an image bearing member such as a photoreceptor or an intermediate transfer belt, and performs electrophotographic processes such as charging, developing, and transferring to the image bearing member. After that, an image is formed and printed on paper.

In addition, since the electrophotographic process is usually performed while rotating the image carrier, one or more drive sources, such as a motor, for rotating the image carrier are provided. First, the driving source is activated.

The speed of the started motor rises to the target speed, but the time it takes to reach the target speed after starting varies depending on the target speed and the connected load. If a stable rotation state is not achieved even after a predetermined period of time has elapsed due to variations, an abnormality is detected and the image forming apparatus stops even though the motor is not out of order. As a result, useless operation stops occur, and the user is required to perform an operation to cancel the abnormality each time.

In order to solve such a problem, it is conceivable to perform a retry to start the motor when a motor abnormality is detected. However, simply retrying to start a motor that has detected an abnormality may result in an abnormal image. The reason for this is as follows.
That is, in the control of the electrophotographic process, it is common to start controlling other loads on the premise that the target speed will be reached after a predetermined time has elapsed since the motor was started. This is because FCOT (first copy time) decreases if other control is started after confirming that the motor has reached the target speed.

A specific example will be described with the process sequence of FIG. Color charging control is started after a predetermined time has elapsed since the color photoreceptor motor M1 was started. If the color charging control is started after confirming that the color photoreceptor motor M1 is in a stable rotation state, FCOT will decrease by the time required for the start-up of the color charging.

In such control, another control is already started at the timing when the abnormality of the motor is detected. Therefore, it is not enough just to retry the motor that detected the abnormality. In other words, if an abnormality in the color photoreceptor motor is detected after the color charging control of FIG. 8 is started and the start of the color photoreceptor motor is retried, the color photoreceptor remains charged, resulting in an abnormal image.

Also, which other load is started to be controlled when a motor abnormality is detected depends on the printing speed and the motor being used. This is because the process startup time is different. If the control of the next load is started after starting the motor until it reaches the target speed, it may be sufficient to retry the start of the motor in which an abnormality is detected. However, such control slows down FCOT as described above.

Japanese Patent Application Laid-Open No. 2002-100000 discloses a copying apparatus that controls driving/stopping during a copying operation while taking into consideration the timing of detecting an abnormality in a motor, which is driving means, and the state of conveyance of a recording medium (paper).

Specifically, if the motor abnormality is detected before the recording medium is fed, the drive is retried.

JP-A-3-69968

However, in the copying apparatus described in Japanese Patent Application Laid-Open No. 2002-200012, if the motor abnormality is detected before the recording medium is fed, the motor is simply retried. Since the motor is simply stopped immediately, there is a risk that an abnormal image will be generated if the motor that detected the abnormality is just retrying due to the fact that other controls have already started when the abnormality of the motor is detected. It is not possible to solve the above-mentioned problem that there is

SUMMARY OF THE INVENTION The present invention has been made in view of such a technical background. It is an object of the present invention to provide an image forming apparatus and a program that make it possible.

The above objects are achieved by the following means.
(1) Photoreceptor, charging means for charging the photoreceptor, developing means for developing a toner image on the photoreceptor, and drive for rotating and driving the photoreceptor during execution of an electrophotographic process for image formation an abnormality detecting means for detecting an abnormality of the driving source; and, when an abnormality of the driving source is detected by the abnormality detecting means, a method of controlling initialization of the electrophotographic process in accordance with the detected timing. and control means for performing initialization control of the determined electrophotographic process, and the abnormality detection means before the start of charging of the photosensitive member by the charging means after activation of the drive source When an abnormality of the drive source is detected by the control means, the control means stops the drive source as the initialization control, and after the start of the drive source and after the charging means starts charging the photoreceptor, When an abnormality of the drive source is detected by the abnormality detection means, the control means stops the drive source as the initialization control to remove the charge on the photoreceptor. After the start of development of the photoreceptor, if the abnormality detection means detects an abnormality in the drive source, the control means further performs a process of removing toner from the surface of the photoreceptor as the initialization control. An image forming apparatus characterized by:
( 2 ) further comprising an intermediate transfer belt to which the toner image of the photoreceptor is transferred, and a pressing means for pressing the intermediate transfer belt against the photoreceptor and separating the photoreceptor from the intermediate transfer belt by the pressing means; When the abnormality detection means detects an abnormality in the drive source after the start of pressure contact with the intermediate transfer belt, the control means controls the initialization of the electrophotographic process by moving the intermediate transfer belt to the photosensitive area via the pressure separation means. 2. The image forming apparatus according to the preceding item 1 , further performing a process of separating the image forming apparatus from the body.
( 3 ) further comprising primary transfer means for transferring the toner image of the photoreceptor onto the intermediate transfer belt by application of a primary transfer voltage; When the detection means detects an abnormality in the drive source, the control means performs a process of removing the toner transferred to the intermediate transfer belt and the charge of the intermediate transfer belt as the initialization control of the electrophotographic process. 3. The image forming apparatus according to 2 above, further implemented.
(4) a photoreceptor, a charging means for charging the photoreceptor, a developing means for developing a toner image on the photoreceptor, an intermediate transfer belt to which the toner image of the photoreceptor is transferred, and an electrophotographic process for image formation a driving source that rotates to drive the intermediate transfer belt when executing; an abnormality detection unit that detects an abnormality in the driving source; a control means for determining a method of initialization control of the electrophotographic process according to the above, and performing the initialization control of the determined electrophotographic process; If an abnormality of the drive source is detected by the abnormality detection means before the start of charging, the control means stops the drive source as the initialization control, and after starting the drive source, the charging means after the start of charging of the photoreceptor, if the abnormality detection means detects an abnormality in the drive source, the control means stops the drive source and removes the charge on the photoreceptor as the initialization control. When the abnormality detection means detects an abnormality in the driving source after the development of the photoreceptor by the developing means is started, the control means performs the initialization control to control the surface of the photoreceptor. An image forming apparatus, further comprising a toner removing process.
( 5 ) further comprising pressure separating means for pressing the intermediate transfer belt against and separating from the photoreceptor, and after the intermediate transfer belt is pressed against the photoreceptor by the pressure separating means, the drive source is detected by the abnormality detection means; 5. The above-described item 4 , wherein when the abnormality is detected, the control means further performs a process of separating the intermediate transfer belt from the photoreceptor via the pressure separating means as the initialization control of the electrophotographic process. Image forming device.
( 6 ) Further comprising primary transfer means for transferring the toner image of the photoreceptor onto the intermediate transfer belt by application of a primary transfer voltage, and after the application of the primary transfer voltage by the primary transfer means is started, the abnormality When the detection means detects an abnormality in the drive source, the control means performs a process of removing the toner transferred to the intermediate transfer belt and the charge of the intermediate transfer belt as the initialization control of the electrophotographic process. 6. The image forming apparatus according to 5 , further implemented.
( 7 ) Speed determining means for determining whether the speed of the driving source has reached a target speed, and the speed determining means determines whether the speed of the driving source has reached the target speed. 7. The image forming apparatus according to any one of 1 to 6 above, in which an electrophotographic process is started.
( 8 ) Speed determining means for determining whether the speed of the driving source has reached a target speed, the speed determining means determining whether the driving source reaches the target speed even after a predetermined time has elapsed after the driving source is activated. 8. The image forming apparatus according to any one of the preceding items 1 to 7 , wherein the abnormality detecting means determines that the driving source is abnormal when it is determined that the driving source is not.
( 9 ) The above item 7 or 8 , wherein the speed determination means determines whether the speed of the drive source has reached the target speed based on the lock signal indicating that the drive source is rotating at the target speed. The described image forming apparatus.
( 10 ) The image forming apparatus according to (7 ) or (8) above, wherein the speed determination means determines whether or not the speed of the drive source has reached a target speed by measuring the pulse frequency of an encoder.
( 11 ) The image forming apparatus according to item 7 or 8 , wherein the speed determination means determines whether or not the speed of the drive source has reached a target speed by measuring the torque of the drive source.
( 12 ) The image forming apparatus according to any one of the preceding items 1 to 11 , wherein the control means executes a retry of the electrophotographic process after executing initialization control of the electrophotographic process.
( 13 ) The image forming apparatus according to ( 12 ) above, wherein when the electrophotographic process is retryed by the control means, the abnormality detection means detects the abnormality of the drive source for a long period of time.
( 14 ) The image forming apparatus according to ( 12) or (13) above, wherein the control means retry the electrophotographic process after the drive source reaches the target speed.
( 15 ) Any one of (12) to ( 14) above, wherein an upper limit is set for the number of retries for the electrophotographic process, and the control means retry the electrophotographic process only when the number of retries is equal to or less than the upper limit. The image forming apparatus according to 1.
( 16 ) The image forming apparatus according to any one of (12) to (15) above, wherein when retrying the electrophotographic process, the control means activates the drive source after adjusting the phase of the drive source.
(17) a photoreceptor, a charging means for charging the photoreceptor, a developing means for developing a toner image on the photoreceptor, and a drive source that rotates and drives the photoreceptor during execution of an electrophotographic process for forming an image; an abnormality detection step of detecting that an abnormality has occurred in the drive source; a control step of determining a method of controlling initialization of the electrophotographic process, and executing the determined initialization control of the electrophotographic process, and performing the control step of performing the initialization control of the electrophotographic process; If an abnormality in the drive source is detected by the abnormality detection step before charging is started, in the control step, the drive source is stopped as the initialization control, and after the drive source is activated, the charging means If the abnormality detection step detects an abnormality in the drive source after the charging of the photoreceptor is started by If the abnormality detection step detects an abnormality in the drive source after the development of the photoreceptor by the developing means is started, the control step performs the initialization control to perform the initialization control on the photoreceptor. A program for performing further processing to remove surface toner.
(18) Photoreceptor, charging means for charging the photoreceptor, developing means for developing a toner image on the photoreceptor, an intermediate transfer belt to which the toner image of the photoreceptor is transferred, and an electrophotographic process for image formation an abnormality detection step of detecting an abnormality of the drive source, and an abnormality of the drive source is detected by the abnormality detection step in a computer of the image forming apparatus having a drive source that rotates and drives the intermediate transfer belt when executing a control step of determining a method of controlling the initialization of the electrophotographic process according to the detected timing when it is detected, and executing the determined initialization control of the electrophotographic process; If an abnormality in the driving source is detected by the abnormality detection step before the charging of the photoreceptor by the charging means is started, the control step stops the driving source as the initialization control, If an abnormality in the drive source is detected by the abnormality detection step after the start of the charging of the photoreceptor by the charging unit after activation of the drive source, the control step performs the initialization control to turn off the drive source. When an abnormality of the drive source is detected by the abnormality detecting step after the development of the photosensitive member by the developing means is started, the controlling step includes the step of: A program for further executing processing for removing toner from the surface of the photoreceptor as initialization control.

According to the invention described in the preceding item (1), when an abnormality is detected in at least one driving source that rotates and drives the driven body during execution of an electrophotographic process for image formation, the timing of the detection is met. Accordingly, the electrophotographic process initialization control method is determined, and the determined initialization control of the electrophotographic process is performed. In other words, instead of simply retrying the driving source, the initialization control of the electrophotographic process is executed according to the timing when the abnormality is detected. Even if there is an error, initialization control can be performed to eliminate the influence of other processes, and the retry of the electrophotographic process can be executed in a state in which the possibility of generating an abnormal image is eliminated. Moreover, it is not necessary for the user to perform an operation to eliminate the abnormality each time an abnormality is detected.
Further, if an abnormality in the driving source is detected after the driving source for rotationally driving the photosensitive member is activated and before charging of the photosensitive member by the charging means is started, the charging of the photosensitive member has not yet been completed. By executing the process of stopping the drive source as the initialization control of the photo process, it is possible to prevent the occurrence of an abnormal image when retrying the electrophotography process.
Further, when an abnormality in the drive source is detected after the drive source for rotationally driving the photoreceptor is activated and the charging of the photoreceptor by the charging means is started, the drive source is stopped as initialization control of the electrophotographic process, and the photoreceptor is exposed. By performing the process of removing the electric charge from the body, it is possible to prevent the occurrence of an abnormal image when retrying the electrophotographic process.
In addition, if an abnormality is detected after the development of the photoreceptor by the developing means is started, processing for removing the toner on the surface of the photoreceptor is further performed as initialization control of the electrophotographic process, so that the abnormality can be eliminated when the electrophotographic process is retried. You can prevent images from occurring.

According to the invention described in the preceding item ( 7 ), since the electrophotographic process is started before it is determined that the speed of the drive source has reached the target speed, a decrease in FCOT can be avoided.
According to the invention described in the preceding item ( 8 ), the drive source is determined to be abnormal when the drive source does not reach the target speed even after the predetermined time has passed since the drive source was started.

According to the invention described in the preceding item ( 9 ), based on the lock signal indicating that the drive source is rotating at the target speed, it is accurately and reliably determined whether the speed of the drive source has reached the target speed. be able to.

According to the invention described in the preceding item ( 10 ), by measuring the pulse frequency of the encoder, it is possible to accurately and reliably determine whether or not the speed of the drive source has reached the target speed.

According to the invention described in the preceding item ( 11 ), by measuring the torque of the drive source, it is possible to accurately and reliably determine whether or not the speed of the drive source has reached the target speed.

According to the invention described in the preceding item ( 12 ), the retry of the electrophotographic process is executed after the execution of the initialization control of the electrophotographic process, so the retry of the electrophotographic process is executed in a state where the initialization control is not executed. It is possible to form an image while eliminating the possibility of the occurrence of an abnormal image.

According to the invention described in the preceding item ( 13 ), when the retry of the electrophotographic process is executed, the time for detecting the abnormality of the driving source is set long. Even if it takes a little longer, it is possible to prevent a re-determination of an abnormality and prevent frequent repetition of abnormality detection.

According to the invention described in the preceding item ( 14 ), the retry of the electrophotographic process is performed after the drive source reaches the target speed, so the retry of the electrophotographic process can be performed in a stable state of the drive source. .

According to the invention described in the preceding item ( 15 ), the retry of the electrophotographic process is executed only when the number of retries of the electrophotographic process is equal to or less than the set upper limit value. It is possible to prevent the use of the image forming apparatus from being interrupted for a long time due to the retry of the photo process being repeated more than necessary.

According to the invention described in the preceding item ( 16 ), when retrying the electrophotographic process, the driving source is activated after the phase adjustment of the driving source is performed. Therefore, the driving source should be activated in an appropriate state. can be done.

According to the invention described in the preceding item ( 2 ), when an abnormality is detected after the intermediary transfer belt is pressed against the photosensitive member by the depressing means, the electrophotographic process is initialized via the depressing means. By separating the transfer belt from the photoreceptor and performing further processing, it is possible to prevent the occurrence of an abnormal image when the electrophotographic process is retried.

According to the invention described in the preceding item ( 3 ), when an abnormality is detected after the application of the primary transfer voltage by the primary transfer means is started, the toner transferred to the intermediate transfer belt and the By further performing the process of removing the charge on the intermediate transfer belt, it is possible to prevent the occurrence of abnormal images when retrying the electrophotographic process.

According to the invention described in the preceding item ( 4 ), when an abnormality in the drive source is detected after the start of the drive source for driving the intermediate transfer belt and before the start of charging of the photoreceptor by the charging means, the photoreceptor is charged. Since charging has not yet been performed, by performing the process of stopping the driving source as the initialization control of the electrophotographic process, it is possible to prevent an abnormal image from being generated when the electrophotographic process is retried.

Further , when an abnormality in the driving source is detected after the driving source for driving the intermediate transfer belt has started and after the charging means has started charging the photoreceptor, the driving source is stopped as an electrophotographic process initialization control, and the photoreceptor is exposed. By performing the process of removing the electric charge from the body, it is possible to prevent the occurrence of an abnormal image when retrying the electrophotographic process.

In addition , if an abnormality is detected after the development of the photoreceptor by the developing means is started, processing for removing the toner on the surface of the photoreceptor is further performed as initialization control of the electrophotographic process, so that the abnormality can be eliminated when the electrophotographic process is retried. You can prevent images from occurring.

According to the invention described in the preceding item ( 5 ), when an abnormality is detected after the intermediary transfer belt is pressed against the photoreceptor by the depressing means, the intermediate transfer belt is transferred via the depressing means as initialization control of the electrophotographic process. By further performing the process of separating the transfer belt from the photoreceptor, it is possible to prevent the occurrence of abnormal images when retrying the electrophotographic process.

According to the invention described in the preceding item ( 6 ), when an abnormality is detected after the application of the primary transfer voltage by the primary transfer means is started, the toner transferred to the intermediate transfer belt and the By further performing the process of removing the charge on the intermediate transfer belt, it is possible to prevent the occurrence of abnormal images when retrying the electrophotographic process.

According to the invention described in the preceding item ( 17 ), the computer of the image forming apparatus having at least one drive source that rotates and drives the driven body during execution of the electrophotographic process for image formation is provided with information indicating whether the drive source malfunctions. is detected, a method for controlling the initialization of the electrophotographic process is determined according to the detected timing, and processing for performing the initialization control of the determined electrophotographic process can be executed.

1 is a diagram showing a schematic configuration of an image forming apparatus according to an embodiment of the invention; FIG. FIG. 2 is a simplified and enlarged view of portions in the vicinity of photoreceptors and an intermediate transfer belt in the image forming apparatus shown in FIG. 1; 2 is a block diagram showing the electrical configuration of the image forming apparatus; FIG. 5 is a flow chart showing a print sequence executed by the image forming apparatus when a user presses a copy button; 4 is a flowchart showing processing for detecting an abnormality in the state of a motor lock signal; 5 is a flow chart showing a process of detecting an abnormality in a motor using a motor pulse frequency obtained by an encoder of the motor; 4 is a flow chart showing a process of measuring motor torque and detecting a motor abnormality. FIG. 5 is a timing chart for explaining an electrophotographic process executed in step S03 of the flowchart of FIG. 4; FIG. 5 is a flow chart showing initialization control processing executed in step S08 of the flow chart of FIG. 4; 5 is a flow chart showing the operation of the image forming apparatus when retrying the electrophotographic process after starting the motor and reaching the target temperature. FIG. 11 is a timing chart for explaining the details of the process of waiting for the stabilization of the motor in step S46 of FIG. 10; FIG.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a schematic configuration of an image forming apparatus 100 according to one embodiment of the invention.

As shown in FIG. 1, the image forming apparatus 100 is a so-called tandem color printer having an intermediate transfer belt 101 as an image carrier. The intermediate transfer belt 101 is an endless belt member, and both ends thereof are supported by rollers 102 and 103 . Image forming units 104Y, 104M, 104C, and 104K for yellow (Y), magenta (M), cyan (C), and black (K) and an image density sensor 105 are arranged along the lower portion of the intermediate transfer belt 101 in the drawing. are placed.

The image forming units 104Y, 104M, 104C, and 104K for each color have the same configuration. Each of the image forming units 104Y, 104M, 104C, and 104K has a photoreceptor drum 106 as an image bearing member and a charging device arranged therearound, as indicated by symbols representative of the image forming unit 104Y. 107 , an exposure device 108 , a developing device 109 and a cleaning device 110 . A primary transfer device 111 is arranged at a position facing the photosensitive drum 106 with the intermediate transfer belt 101 interposed therebetween.

A paper feeding device 112 that accommodates paper P is arranged in the lower portion of the image forming apparatus 100 . A paper feeding roller 113 for feeding the paper P is provided on the upper portion of the paper feeding device 112 . The paper P is sent upward along the transport path 114 from the paper feeder 112 . A secondary transfer device 115 is arranged at a position facing the roller 103 with the transport path 114 interposed therebetween. Furthermore, the fixing device 1 is arranged on the downstream side (upper side in the figure). The fixing device 1 has a heating roller 11 and a pressure roller 12 . Discharge rollers 116 and a discharge tray 117 are arranged on the further downstream side of the transport path 114 from the fixing device 1 .

Next, the operation of the image forming apparatus 100 shown in FIG. 1 will be briefly described. The image forming apparatus 100 forms an image by executing an electrophotographic process, and upon receiving an image forming instruction, generates image data of each color from the image signal. The generated image data for each color is sent to the corresponding image forming units 104Y, 104M, 104C, and 104K, respectively. The image forming units 104Y, 104M, 104C, and 104K for each color charge and expose the respective photosensitive drums 106 based on image data to form electrostatic latent images. Further, the formed electrostatic latent image is developed to form a toner image.

The formed toner images are sequentially transferred to the intermediate transfer belt 101 by the primary transfer device 111 and superimposed. The toner image superimposed on the intermediate transfer belt 101 is transferred onto the paper P by the secondary transfer device 115 . The paper P bearing the toner image is further conveyed to reach the fixing device 1 , where it is heated and pressed by the fixing device 1 . The toner image is fixed on the paper P by this. The paper P on which the toner image is fixed is discharged to a paper discharge tray 117 by paper discharge rollers 116 .

FIG. 2 shows the drive systems of the photoreceptor drums 106Y, 106M, 106C, and 106K in the image forming units 104Y, 104M, 104C, and 104K, and the intermediate transfer belt 101. FIG. 106C, 106K, and a simplified enlarged view of the vicinity of the intermediate transfer belt 101; FIG. In the following description, the photosensitive drums 106Y, 106M, 106C, and 106K are used when the individual photosensitive drums need to be indicated, and the photosensitive drum 106 is used when the entire photosensitive drums are indicated.

In this embodiment, the photoreceptor drums 106Y, 106M, and 106C of the color image forming units 104Y, 104M, and 104C are driven by a common color photoreceptor motor (corresponding to a drive source) M1 to form a black image. The photosensitive drum 106K of the forming unit 104K is driven by a main motor (corresponding to a drive source) M2, and the intermediate transfer belt 101 is also driven by the main motor M2 via the roller 103. FIG. In this embodiment, brushless motors, for example, are used as the color photoreceptor motor M1 and the main motor M2.

Note that the color photoreceptor drums 106Y, 106M, and 106C may be driven by individual drive motors instead of being driven by one common color photoreceptor motor M1. Also, the black photosensitive drum 106K and the intermediate transfer belt 101 may be driven by individual drive motors instead of being driven by the common main motor M2.

FIG. 3 is a block diagram showing the electrical configuration of the image forming apparatus 100. As shown in FIG. The image forming apparatus 100 includes a control unit 200, a storage device 210, an image reading device 220, an operation panel 230, an image output device 240, a printer controller 250, a network interface (network I/F) 260, a wireless communication interface (wireless communication I/ F) 270 , an authentication unit 280 , a motor speed detection unit 290 , etc., which are connected to each other via a system bus 275 .

The control unit 200 includes a CPU (Central Processing Unit) 201, a ROM (Read Only Memory) 202, an S-RAM (Static Random Access Memory) 203, an NV-RAM (Non Volatile RAM) 204, a clock IC 205, and the like.

The CPU 201 comprehensively controls the entire image forming apparatus 100 by executing an operation program stored in the ROM 202 or the like. For example, the copy function, printer function, etc. are controlled to be executable. Furthermore, in this embodiment, it is determined whether the speed of the color photoreceptor motor M1 or the main motor M2 has reached the target temperature when executing the print job or the print job, and if an abnormality occurs in the color photoreceptor motor M1 or the main motor M2. When it is detected that an abnormality has occurred, initialization control and retry control of the electrophotographic process by the image output device 240 are performed according to the detected timing, the details of which will be described later.

The ROM 202 stores programs executed by the CPU 201 and other data.

The S-RAM 203 serves as a work area when the CPU 201 executes a program, and temporarily stores the program and data used when the program is executed.

The NV-RAM 204 is a non-volatile memory backed up by a battery, and stores various settings related to image formation.

The clock IC 205 measures time and functions as an internal timer to measure processing time.

The storage device 210 is composed of a hard disk or the like, and stores various data such as image data of a document read by the image reading device 220 and print data transmitted from an external terminal device.

The image reading device 220 has a scanner or the like, reads a document set on a platen glass by scanning the document, and converts the read document into image data.

The operation panel 230 is used when a user instructs a job or the like to the image forming apparatus 100 or performs various settings, and includes a reset key 231, a start key 232, a stop key 233, a display section 234, a touch panel 235, and the like. ing.

A reset key 231 is used to reset settings, a start key 232 is used to start operations such as scanning, and a stop key 233 is pressed to interrupt an operation. is.

The display unit 234 is composed of, for example, a liquid crystal display device and displays messages, various operation screens, etc. A touch panel 235 is formed on the screen of the display unit 234 and detects a user's touch operation.

The image output device 240 prints on paper a copied image generated by an electrophotographic process from the image data of the document read by the image reading device 220 or the print data transmitted from the terminal device, and outputs the printed matter. be. The image output device 240 includes the intermediate transfer belt 101, the image forming units 104Y, 104M, 104C, and 104K, the image density sensor 105, the primary transfer device 111, the paper feeding device 112, and the paper feeding device 112 for forming images. A roller 113, a conveying path 114, a secondary transfer device 115, a fixing device 1, a paper discharge roller 116, a paper discharge tray 117, and the like are included.

Printer controller 250 generates a copy image from print data received by network I/F 260 .

The network I/F 260 functions as communication means for transmitting and receiving data to and from an external device such as a terminal device via a network, and the wireless communication I/F 270 communicates with the external device by short-range wireless communication. It is an interface for

The authentication unit 280 acquires the authentication information of the logged-in user, and performs authentication by comparing the authentication information with the information for comparison previously stored in the storage device 210 or the like. Note that the comparison and collation between the user authentication information and the collation information may be performed by an external authentication server, and the authentication may be performed by the authentication unit 280 receiving the authentication result from the authentication server.

A motor speed detector 290 detects the speed of the color photoreceptor motor M1 and the main motor M2, and is composed of, for example, an encoder or a torque detector.
Next, operations of the image forming apparatus 100 shown in FIGS. 1 to 3 will be described.

<Print sequence>
A print sequence executed by the image forming apparatus 100 when the user presses the copy button will be described based on the flowchart of FIG. 4 and 5 are executed by the CPU 201 in the control unit 200 of the image forming apparatus 100 operating according to an operation program in the ROM 202 or the like.

When the printing sequence is started, the retry count of the electrophotographic process is cleared to zero in step S01. The retry count of the electrophotographic process refers to the number of electrophotographic processes executed after predetermined initialization control processing when an abnormality is detected in the color photoreceptor motor M1 or the main motor M2 (hereinafter also simply referred to as motors M1 and M2). Number of retries for the process.

Next, in step S02, the time until the abnormality of the motors M1 and M2 is detected is set to (the number of retries + 2) seconds, and the abnormality detection time is extended according to the number of retries. Next, in step S03, the electrophotographic process sequence is executed until printing is completed, and in step S04, it is determined whether or not printing is completed. When printing is completed (YES in step S04), the process ends. The electrophotographic process sequence will be described later.

If printing is not completed (NO in step S04), motor abnormality detection processing is executed in step S05. The motor abnormality detection processing will be described later. In step S06, it is determined whether or not at least one of the motors M1 and M2 has an abnormality based on the result of the motor abnormality detection process. If there is no abnormality (NO in step S06), the process returns to step S02, and steps S02 to S06 are repeated until printing is completed. If an abnormality is detected in at least one of the motors M1 and M2 (YES in step S06), it is checked in step S07 whether the number of process retries is equal to or greater than a preset upper limit value (two times in this embodiment). If so (YES in step S07), the machine (image forming apparatus) is trouble-stopped in step S10, and the occurrence of an abnormality is displayed on the display unit 234 of the operation panel 230 in step S11.

If the number of process retries is less than the upper limit value in step S07 (NO in step S07), initialization control is executed in step S08, the number of process retries is incremented in step S09, and the process returns to step S02. Then, in step S02, the time until an abnormality is detected is set to (the number of retries + 2) seconds, and then in step S03, the process sequence is executed (retryed) again. The details of the initialization control in step S08 will be described later.

As described above, when the retry of the electrophotographic process is executed, in step S02, the time for detecting the abnormality of the motors M1 and M2 is set longer. Even if the time until the detection becomes longer, it is possible to prevent the abnormality from being determined again, and to prevent the abnormality detection from being repeated frequently.

<Motor abnormality detection processing>
The motor abnormality detection process in step S05 of FIG. 4 will be described. In this embodiment, if the motors M1 and M2 do not reach the target speed even after a predetermined period of time has passed since they were started, it is determined that the motors M1 and M2 are abnormal. There are multiple processes depending on how to determine whether the velocity has reached the target velocity.

The first process is a process of detecting an abnormality in the states of the lock signals of the motors M1 and M2, and the contents thereof will be described with reference to the flow chart of FIG.

The lock signal is a signal that is locked when the speeds of the motors M1 and M2 are within a predetermined range (for example, ±6.25%) of the target speed, and unlocked otherwise.

First, in step S0501, no abnormality is set in the motor abnormality status. Next, when printing is started and the motors M1 and M2 are activated, the state of the lock signal is checked in step S0502. If the lock signal is in the locked state (YES in step S0502), the process returns to step S06 in FIG. In this case, it is determined that there is no abnormality.

If it is in the unlocked state (NO in step S0502), in step S0503, the time during which the unlocked state continued after starting the motors M1 and M2 is equal to or longer than the abnormality detection time set in step S02 of FIG. determine whether or not If the abnormality detection time is exceeded (YES in step S0503), the motor abnormality status is set to "abnormal" in step S0504, and then the process returns. In this case, it is determined that an abnormality has occurred in the motors M1 and M2.

In step S0503, if the duration of the unlocked state is not equal to or longer than the abnormality detection time (NO in step S0503), the duration of the unlocked state is incremented in step S0505, and then the process returns. In this case, motor abnormality detection is continued.

The second process for motor abnormality detection is a process using the motor pulse frequencies obtained by the encoders of the motors M1 and M2, and the details thereof will be described with reference to the flowchart of FIG.

First, in step S0511, the motor abnormality status is set to no abnormality. Next, when printing is started and the motors M1 and M2 are started, it is determined in step S0512 whether or not the encoder pulse frequency is equal to or higher than the target speed. If the speed is equal to or higher than the target speed (YES in step S0512), the process returns to step S06 in FIG. In this case, it is determined that there is no abnormality.

If the encoder pulse frequency is not equal to or higher than the target speed (NO in step S0512), in step S0513, the time during which the motors M1 and M2 have not reached the target speed after starting is determined as the abnormality set in step S02 of FIG. Determine whether or not the detection time is exceeded. If the abnormality detection time is exceeded (YES in step S0513), the motor abnormality status is set to "abnormal" in step S0514, and then the process returns. In this case, it is determined that an abnormality has occurred in the motors M1 and M2.

In step S0513, if the time during which the target speed has not been reached is not longer than the abnormality detection time (NO in step S0513), in step S0515, the time during which the target speed has not been reached is incremented, and then the process returns. In this case, motor abnormality detection is continued.

The third process of motor abnormality detection is a process of measuring the torques of the motors M1 and M2, and the contents thereof will be described with reference to the flowchart of FIG.

First, in step S0521, the motor abnormality status is set to no abnormality. Next, when printing is started and the motors M1 and M2 are started, it is determined in step S0522 whether or not the current torque is equal to or higher than the target speed. If the speed is equal to or higher than the target speed (YES in step S0512), the process returns to step S06 in FIG. In this case, it is determined that there is no abnormality.

If the current torque is not equal to or higher than the target speed (NO in step S0522), in step S0523, the time during which the torque of the motors M1 and M2 has not reached the target speed after starting is set in step S02 of FIG. It is determined whether or not the specified abnormality detection time is exceeded. If the abnormality detection time is exceeded (YES in step S0523), the motor abnormality status is set to "abnormal" in step S0524, and then the process returns. In this case, it is determined that an abnormality has occurred in the motors M1 and M2.

In step S0523, if the time during which the torque of the target speed is not reached is not longer than the abnormality detection time (NO in step S0523), in step S0525, the time during which the target speed is not reached is incremented, and then the process returns. In this case, motor abnormality detection is continued.

As described above, in this embodiment, if the motors M1 and M2 do not reach the target speed even after a predetermined time has passed since the motors M1 and M2 started, an abnormality of the motors M1 and M2 is detected. Even after the motors M1 and M2 have reached the target speed, the speed monitoring may be continued, and even when the speed becomes unstable during the operation of the motors M1 and M2, it may be judged to be abnormal.

<Process sequence>
The processing of the electrophotographic process sequence executed in step S03 of the flowchart of FIG. 4 will be described with reference to the timing chart of FIG.

Before the start of the electrophotographic process, the color photoreceptor motor M1 and the main motor M2 are stopped, and the intermediate transfer belt 101 and each photoreceptor drum 106 are separated (belt pressure separation). Charging (color charging) and development (color development) of the color photosensitive drums 106Y, 106M, and 106C, charging (monochrome charging) and developing (monochrome development) of the monochrome photosensitive drum 106K, primary transfer, and secondary transfer are also performed. not started.

When the color photoreceptor motor M1 is started at the timing T11, the color photoreceptor motor M1 is being started up until the timing T12, and reaches the target speed at the timing T12 and becomes stable rotation.

At timing T21 during startup before the color photoreceptor motor M1 reaches the target speed, the charging devices 107 of the color image forming units 104Y, 104M and 104C are operated to charge the color photoreceptor drums 106Y, 106M and 106C. to start. The charging operation is starting up until timing T22, and the output becomes stable at timing T22.

At timing T31 after the charging operation is stabilized, development by the developing device 109 is started.

The main motor M2 is started at a timing T41 during startup of the color photoreceptor motor M1 and charging operation of the color photoreceptor drums 106Y, 106M, and 106C. The main motor M2 is in the process of starting up until timing T42, and reaches the target speed at timing T42 and becomes stable rotation.

At timing T51 during startup before the main motor M2 reaches the target speed, the charging device 107 of the black image forming section 104K is operated to start charging the monochrome photosensitive drum 106K. The charging operation is starting up until timing T52, and the output becomes stable at timing T52. At timing T61 after the charging operation is stabilized, monochrome development by the developing device 109 is started.

After the start of monochrome development, at timing T71, the intermediate transfer belt 101 is switched from the separated state to the pressure contact state with respect to the photosensitive drum 106 . Switching is in progress until timing T72, and the switching is completed at timing T72 to enter the pressure contact state.

Almost simultaneously with the switching completion timing T72, primary transfer is performed by the primary transfer device 111, and secondary transfer is performed by the secondary transfer device 115 at subsequent timing T91.

Thus, in this embodiment, charging of the color photoreceptor drums 106Y, 106M, and 106C is started before the color photoreceptor motor M1 reaches the target speed after activation. Similarly, charging of the monochrome photoreceptor drum 106K is started before the target speed is reached after the main motor M2 is activated. Before the motors M1 and M2 reach their target speeds, charging, which is the first process in the electrophotographic process, is started, so that FCOT can be prevented from decreasing. However, charging is not limited to starting before the motors M1 and M2 reach their target speeds, and charging may start after the motors M1 and M2 reach their target speeds.
<Initialization control>
The initialization control process executed in step S08 of the flowchart of FIG. 4 will be described with reference to the flowchart of FIG.

When the color photoreceptor motor M1 and the main motor M2 are started, motor abnormality detection processing is started, and electrophotographic processes such as charging and development are started. Which process in the electrophotographic process is started when it is detected that at least one of the color photoreceptor motor M1 and the main motor M2 is abnormal depends on printing productivity and the like. Therefore, in this embodiment, initialization control is performed according to the timing at which the motor abnormality is detected.

If at least one of the motors M1 and M2 becomes abnormal, the motor in which the abnormality occurs is stopped in step S21. Subsequently, a process is executed according to the timing when the abnormality occurs.

That is, in step S22, it is determined whether primary transfer has already started for at least one of the color image and the monochrome image. If the primary transfer has not started at the timing of the motor abnormality detection (NO in step S22), it is determined in step S28 whether the intermediate transfer belt 101 has started pressing against the photosensitive drum 106 or not.

If pressure contact has not started (NO in step S28), it is determined in step S29 whether or not development has started on at least one of the photosensitive drums 106. If development has not started (NO in step S29), the process proceeds to step S30. .

In step S30, it is determined whether or not charging of at least one of the photosensitive drums 106 has been started at the timing of motor abnormality detection. If charging has not started (NO in step S30), the process proceeds to step S27.

As described above, if charging has not started on any of the photosensitive drums 106 at the timing of motor abnormality detection, any of the processes of charging, development, pressure contact of the intermediate transfer belt 101 to the photosensitive drums 106, and primary transfer can be performed. Since it has not been executed, by executing only the process of stopping the motors M1 and M2 as the initialization control of the electrophotographic process, it is possible to prevent an abnormal image from being generated when the electrophotographic process is retried.

In step S30, if at least one of the photoreceptor drums 106 has already started charging at the timing of the motor abnormality detection (YES in step S30), the process of removing the charge of the photoreceptor drums 106 is performed in step S26. The process proceeds to step S27. That is, if a motor abnormality is detected after charging is started, an abnormal image will occur if the electrophotographic process is retried while the charge remains on the photosensitive drum 106. Therefore, the motors M1 and M2 are stopped as an initialization control process. Then, a process for removing the charge from the photosensitive drum 106 is performed. As a result, it is possible to prevent an abnormal image from occurring when the electrophotographic process is retried.

In step S29, if development has already started for at least one of the photosensitive drums 106 at the timing of motor abnormality detection (YES in step S29), the toner on the photosensitive drums 106 is removed in step S25, and step After removing the charge from the photosensitive drum 106 in S26, the process proceeds to step S27. If a motor abnormality is detected after the start of development, an abnormal image will occur if the electrophotographic process is retried while toner and charge remain on the photosensitive drum 106. Therefore, the motors M1 and M2 are turned on as initialization control processing. After stopping, processing for removing toner and charge from the photosensitive drum 106 is performed. As a result, it is possible to prevent an abnormal image from occurring when the electrophotographic process is retried.

In step S28, if the intermediate transfer belt 101 has already started pressing against the photosensitive drum 106 at the timing of motor abnormality detection (YES in step S28), in other words, pressing the intermediate transfer belt 101 against the photosensitive drum 106 starts. If a motor abnormality is detected later, the intermediate transfer belt 101 is removed in step S24 in order to prevent the photosensitive drum 106 from being charged due to friction between the intermediate transfer belt 101 and the photosensitive drum 106, resulting in an abnormal image. It is separated from the photosensitive drum 106 . Further, the toner on the photoreceptor drum 106 is removed in step S25, and the charge on the photoreceptor drum 106 is removed in step S26. As a result, it is possible to prevent an abnormal image from being generated when the electrophotographic process is retried.

In step S22, if the primary transfer has already started at the timing of the motor abnormality detection, in other words, if the abnormality detection timing is after the start of the primary transfer (YES in step S22), the intermediate transfer belt 101 has charge and toner. In order to prevent the residual image from becoming an abnormal image, the charge and toner on the intermediate transfer belt 101 are removed in step S23. Further, after separating the intermediate transfer belt 101 from the photoreceptor drum 106 in step S24, removing the toner on the photoreceptor drum 106 in step S25, and removing the charge of the photoreceptor drum 106 in step S26, The process proceeds to step S27. As a result, it is possible to prevent an abnormal image from being generated when the electrophotographic process is retried.

In step S27, the phases of the motors M1 and M2 that have detected an abnormality are adjusted, and the process returns to step S08 in FIG. 4 and proceeds to step S09. Since the phases of the motors M1 and M2 that have detected an abnormality are adjusted, the motors M1 and M2 can be started in a proper state when the electrophotographic process is retried later.

As described above, in this embodiment, when an abnormality is detected in the motors M1 and M2, the initialization process determined according to the timing of the abnormality detection is executed. Even if another process has already started at the timing, initialization control is performed to eliminate the influence of the other process, and the retry of the electrophotographic process is performed in a state in which the risk of abnormal images is eliminated. can be executed. Moreover, the user does not need to perform an operation to eliminate the abnormality each time an abnormality of the motors M1 and M2 is detected.

<Other embodiments>
The retry process sequence in the flowchart shown in FIG. 4 executes the same processing as the non-retry process sequence in which no motor abnormality is detected.

However, when retrying, in order to ensure that printing is completed normally, other processes should be started after a sufficient amount of time has passed from the start of the motors M1 and M2 until the target temperatures are reached and stabilized. You can do it. As a result, the electrophotographic process can be retried while the motors M1 and M2 are stable.

The operation of the image forming apparatus 100 when the motors M1 and M2 are started and the target temperature is reached and then the retry is executed will be described with reference to the flowchart of FIG.

When the printing sequence is started, in step S41, the electrophotographic process sequence is executed until the printing is completed, and in step S42, it is determined whether or not the printing is completed. When printing is completed (YES in step S42), the process ends.

If printing is not completed (NO in step S42), motor abnormality detection processing is executed in step S43. The motor abnormality detection process is the same as the motor abnormality detection process of step S05 in the flowchart of FIG. In step S44, it is determined whether or not at least one of the motors M1 and M2 has an abnormality based on the result of the motor abnormality detection process. If there is no abnormality (NO in step S44), the process returns to step S41, and steps S41 to S44 are repeated until printing is completed. If an abnormality is detected in at least one of the motors M1 and M2 (YES in step S44), initialization control is executed in step S45, and then the process proceeds to step S46. Initialization control is the same as the processing described in the flowchart of FIG.

In step S46, a process sequence for waiting for the motor to stabilize is executed (retryed). A process sequence for waiting for the motor to stabilize will be described later.

Next, in step S47, it is determined whether printing is completed. When printing is completed (YES in step S47), the process ends. If printing has not been completed (NO in step S47), in step S48, it is determined whether or not at least one of the motors M1 and M2 has an abnormality. If there is no abnormality (NO in step S48), the process returns to step S46. If an abnormality is detected (YES in step S48), the machine (image forming apparatus) is trouble-stopped in step S49, and the occurrence of the abnormality is displayed on display section 134 of operation panel 130 in step S50. Note that an upper limit value may be set for the number of retries of the process sequence.

The details of the process sequence for waiting for the stabilization of the motor in step S46 will be described with reference to the timing chart of FIG.

When the color photoreceptor motor M1 is started at timing T15, the color photoreceptor motor M1 is being started up until timing T16, and reaches the target speed at timing T16 and becomes stable rotation. After a sufficient time (color photoreceptor motor stabilization time) has passed after the color photoreceptor motor M1 is started and stabilized, color charging control is started at timing T25.

Also, when the main motor M2 is started at timing T45, it continues to start up until timing T46, reaches the target speed at timing T46, and becomes stable. Monochrome charging control is started at timing T55 after a sufficient time has elapsed from the start of the main motor M2 until it becomes stable.

Since the start timing of color charge control and the start timing of monochrome charge control are thus delayed, the start timings of color development, monochrome development, belt release, primary transfer, and secondary transfer are also delayed accordingly.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment. For example, the driving sources to be subject to abnormality detection are the color photoconductor motor M1 that drives the photoconductor drums 106Y, 106M, and 106C, which are image carriers, and the intermediate transfer belt 101 and photoconductor drum 106K, which are also image carriers. Although the case where the black main motor M2 is driven is shown, the drive source to be detected as an abnormality is a fixing motor, paper feed motor, conveying motor, or the like, which rotates during the electrophotographic process for image formation. Any device that drives the driving body may be used.

100 image forming apparatus 101 intermediate transfer belt 102, 103 rollers 104Y, 104M, 104C, 104K image forming units 106, 106Y, 106M, 106C, 106K photosensitive drums 107 charging device 108 exposure device 109 developing device 111 primary transfer device 115 2 Next transfer device 200 Control unit 201 CPU
202 ROMs
230 Operation panel M1, M2 Motor (drive source)

Claims (18)

a photoreceptor, a charging means for charging the photoreceptor, a developing means for developing a toner image on the photoreceptor, a driving source that rotates and drives the photoreceptor during execution of an electrophotographic process for image formation,
an abnormality detection means for detecting an abnormality of the drive source;
When an abnormality of the drive source is detected by the abnormality detection means, a method of initialization control of the electrophotographic process is determined according to the detected timing, and initialization control of the determined electrophotographic process is performed. a control means for
with
When the abnormality detecting means detects an abnormality in the driving source after the activation of the driving source and before the charging means starts charging the photoreceptor, the control means controls the driving source as the initialization control. stop the source and
When the abnormality detecting means detects an abnormality in the driving source after the charging means starts charging the photosensitive member after the activation of the driving source, the control means controls the driving as the initialization control. stopping the source and performing a process to remove the charge on the photoreceptor;
When the abnormality detection means detects an abnormality in the driving source after the developing means starts developing the photoreceptor, the control means performs a process of removing toner from the surface of the photoreceptor as the initialization control. An image forming apparatus , further comprising : The apparatus further comprises an intermediate transfer belt onto which the toner image of the photosensitive member is transferred, and a pressure separating means for pressing the intermediate transfer belt against and away from the photosensitive member, wherein the intermediate transfer belt is pressed against the photosensitive member by the pressure separating means. After the start, if the abnormality detection means detects an abnormality in the drive source, the control means separates the intermediate transfer belt from the photoreceptor via the separation means as the initialization control of the electrophotographic process. 2. The image forming apparatus according to claim 1 , further comprising: a primary transfer unit for transferring the toner image on the photoreceptor to the intermediate transfer belt by applying a primary transfer voltage; and after the primary transfer unit starts applying the primary transfer voltage, When an abnormality of the drive source is detected, the control means further performs a process of removing the toner transferred to the intermediate transfer belt and the charge of the intermediate transfer belt as the initialization control of the electrophotographic process. The image forming apparatus according to claim 2 . A photoreceptor, a charging means for charging the photoreceptor, a developing means for developing a toner image on the photoreceptor, an intermediate transfer belt to which the toner image of the photoreceptor is transferred, and an electrophotographic process for forming an image. a drive source that rotates to drive the intermediate transfer belt;
an abnormality detection means for detecting an abnormality of the drive source;
When an abnormality of the drive source is detected by the abnormality detection means, a method of initialization control of the electrophotographic process is determined according to the detected timing, and initialization control of the determined electrophotographic process is performed. a control means for
with
When the abnormality detecting means detects an abnormality in the driving source after the activation of the driving source and before the charging means starts charging the photoreceptor, the control means controls the driving source as the initialization control. stop and
When the abnormality detecting means detects an abnormality in the driving source after the charging means starts charging the photoreceptor after the activation of the driving source, the control means controls the driving source as the initialization control. Stopping and performing a process to remove the charge of the photoreceptor,
When the abnormality detection means detects an abnormality in the driving source after the developing means starts developing the photoreceptor, the control means performs a process of removing toner from the surface of the photoreceptor as the initialization control. An image forming apparatus, further comprising: The photoreceptor further comprises a pressure separating means for pressing the intermediate transfer belt against and separating from the photoreceptor, and after the pressure separating means starts pressing the intermediate transfer belt against the photoreceptor, an abnormality of the drive source is detected by the abnormality detection means. 5. The image forming method according to claim 4 , wherein, when detected, said control means further performs a process of separating the intermediate transfer belt from said photoreceptor via said separating means as said initialization control of the electrophotographic process. Device. a primary transfer unit for transferring the toner image on the photoreceptor to the intermediate transfer belt by applying a primary transfer voltage; and after the primary transfer unit starts applying the primary transfer voltage, When an abnormality of the drive source is detected, the control means further performs a process of removing the toner transferred to the intermediate transfer belt and the charge of the intermediate transfer belt as the initialization control of the electrophotographic process. The image forming apparatus according to claim 5 . comprising speed determination means for determining whether the speed of the drive source has reached a target speed;
7. The image forming apparatus according to claim 1, wherein said electrophotographic process is started before said speed determining means determines that the speed of said drive source has reached a target speed. comprising speed determination means for determining whether the speed of the drive source has reached a target speed;
2. When the speed determination means determines that the drive source has not reached the target speed even after a predetermined time has passed since the start of the drive source, the abnormality detection means determines that the drive source is abnormal. 8. The image forming apparatus according to any one of 7 . 9. The speed determination means according to claim 7 , wherein the speed determination means determines whether or not the speed of the drive source has reached the target speed based on a lock signal indicating that the drive source is rotating at the target speed. Image forming device. 9. The image forming apparatus according to claim 7 , wherein the speed determination means determines whether or not the speed of the drive source has reached the target speed by measuring the pulse frequency of an encoder. 9. The image forming apparatus according to claim 7 , wherein the speed determination means determines whether or not the speed of the drive source has reached a target speed by measuring the torque of the drive source. 12. The image forming apparatus according to any one of claims 1 to 11 , wherein the control means executes a retry of the electrophotographic process after executing initialization control of the electrophotographic process. 13. The image forming apparatus according to claim 12 , wherein when the electrophotographic process is retryed by the control means, the abnormality detecting means sets a long time for detecting the abnormality of the drive source. 14. The image forming apparatus according to claim 12 , wherein said control means executes a retry of the electrophotographic process after said drive source reaches a target speed. An upper limit is set for the number of retries for the electrophotographic process,
15. The image forming apparatus according to any one of claims 12 to 14 , wherein said control means executes a retry of the electrophotographic process only when said number of retries is equal to or less than an upper limit. 16. The image forming apparatus according to any one of claims 12 to 15 , wherein when retrying the electrophotographic process, the control means starts the drive source after adjusting the phase of the drive source. It has a photoreceptor, a charging means for charging the photoreceptor, a developing means for developing a toner image on the photoreceptor, and a drive source that rotates and drives the photoreceptor during execution of an electrophotographic process for image formation. on the computer of the image forming device,
an abnormality detection step of detecting that an abnormality has occurred in the drive source;
When an abnormality of the drive source is detected by the abnormality detection step, a method of initialization control of the electrophotographic process is determined according to the detected timing, and the determined initialization control of the electrophotographic process is performed. a control step;
and
If an abnormality in the drive source is detected by the abnormality detection step after the start of the drive source and before the charging unit starts charging the photoreceptor, the control step performs the initialization control as the initialization control. stop the source,
If an abnormality of the drive source is detected by the abnormality detection step after the start of charging of the photoreceptor by the charging unit after activation of the drive source, the control step performs the initialization control by performing the initialization control. stopping the source and performing a process to remove the charge on the photoreceptor;
If the abnormality detection step detects an abnormality in the drive source after the developing means starts developing the photoreceptor, the control step performs a process of removing toner from the surface of the photoreceptor as the initialization control. program to further implement A photoreceptor, a charging means for charging the photoreceptor, a developing means for developing a toner image on the photoreceptor, an intermediate transfer belt to which the toner image of the photoreceptor is transferred, and an electrophotographic process for forming an image. a computer of an image forming apparatus having a drive source that rotates to drive the intermediate transfer belt;
an abnormality detection step of detecting an abnormality in the drive source;
When an abnormality of the drive source is detected by the abnormality detection step, a method of initialization control of the electrophotographic process is determined according to the detected timing, and initialization control of the determined electrophotographic process is performed. a control step to
and
If an abnormality in the drive source is detected by the abnormality detection step after activation of the drive source and before charging of the photoreceptor by the charging unit is started, the control step performs the initialization control to turn off the drive source. stop,
If an abnormality in the drive source is detected by the abnormality detection step after the start of the charging of the photoreceptor by the charging unit after activation of the drive source, the control step performs the initialization control to turn off the drive source. stopping and performing a process of removing the charge of the photoreceptor;
If the abnormality detection step detects an abnormality in the drive source after the developing means starts developing the photoreceptor, the control step performs a process of removing toner from the surface of the photoreceptor as the initialization control. program to further implement

Images