JP5019959B2 - Image forming apparatus, image forming method, and semiconductor device - Google Patents

Description

  The present invention relates to an image forming apparatus, an image forming method, and a semiconductor device having a middle transfer driving motor that drives an intermediate transfer belt and a secondary transfer motor that rotates a secondary transfer roller.

  In the image forming apparatus, when the toner image primarily transferred from the photosensitive drum onto the intermediate transfer belt is transferred to the recording paper, the secondary transfer roller and the intermediate transfer belt are pressed against each other to sandwich the recording paper. Some transfer a toner image on a transfer belt onto a recording sheet.

  In such an image forming apparatus, the peripheral speed of the secondary transfer roller and the surface speed of the intermediate transfer belt are the same in order to prevent image misalignment when the toner image is transferred to the recording paper. preferable. Therefore, various contrivances have been made for control to eliminate the speed difference between the peripheral speed of the secondary transfer roller and the surface speed of the intermediate transfer belt.

  For example, in an image forming apparatus having a structure in which a secondary transfer roller in contact with the intermediate transfer belt is rotated by the intermediate transfer belt and rotated, intermediate transfer is performed to eliminate the difference between the peripheral speed of the secondary transfer roller and the surface speed of the intermediate transfer belt. Controls the surface speed of the belt.

  As a conventional technique for controlling the surface speed of the intermediate transfer belt, an intermediate transfer drive motor that rotates the intermediate transfer drive roller by attaching an encoder to the drive shaft of the intermediate transfer drive roller that drives the intermediate transfer belt and feeding back the encoder signal. Control techniques are generally known. In addition, for example, a scale for measuring the moving distance of the intermediate transfer belt is provided, the speed of the intermediate transfer belt is detected by a scale sensor indicating the moving distance of the intermediate transfer belt, and the intermediate transfer drive is performed based on the detected speed of the intermediate transfer belt There is a technology for controlling a motor.

Further, as a control technique in an image forming apparatus configured to drive a secondary transfer roller with a motor for a secondary transfer roller, for example, in Patent Document 1, a speed fluctuation profile of an intermediate transfer belt is detected in advance to detect the secondary transfer roller. An image forming apparatus is described in which the rotational speed is driven by an antiphase profile of the intermediate transfer belt speed profile to cancel the speed fluctuation of the intermediate transfer belt speed.
JP 2005-338703 A

  However, the roller diameter of the secondary transfer roller is easily affected by a temperature rise or the like, and when the secondary transfer roller diameter expands, the peripheral speed of the secondary transfer roller increases. When the peripheral speed of the secondary transfer roller increases, a speed difference is generated between the peripheral speed of the secondary transfer roller and the surface speed of the intermediate transfer belt, and as a result, the intermediate transfer belt is dragged by the secondary transfer roller. Will occur. When the accompanying rotation occurs, the intermediate transfer driving roller for driving the intermediate transfer belt is rotated by the intermediate transfer belt and the rotation speed is increased.

  A brushless motor is generally used as the intermediate transfer drive motor that controls the rotation of the intermediate transfer roller, but the speed adjustment in the brushless motor drive is performed by adjusting the torque by PWM duty by PWM (Pulse Width Modulation) control. Do. For this reason, when the rotational speed of the intermediate transfer drive roller is increased by the accompanying rotation and the load torque acting on the drive shaft of the intermediate transfer drive roller becomes a negative value, deceleration (brake) control cannot be performed and The rotational speed of the drive roller is in an uncontrollable state.

  Therefore, in the image forming apparatus having a structure in which the secondary transfer roller is rotated by the intermediate transfer belt, the rotation speed of the intermediate transfer driving roller cannot be controlled when the rotation occurs, and the surface speed of the intermediate transfer belt is reduced. I can't control it. For this reason, the accompanying state cannot be eliminated.

  Further, in the image forming apparatus configured to drive the secondary transfer roller described in Patent Document 1 with a motor for the secondary transfer roller, a preset intermediate transfer belt speed profile is used. The difference in speed between the surface speed of the intermediate transfer belt and the peripheral speed of the secondary transfer roller due to expansion cannot be canceled out. Therefore, if the intermediate transfer belt is rotated due to the expansion of the secondary transfer roller, this cannot be eliminated.

  The present invention has been made in view of the above-described problems, and has been made to solve this problem. When the intermediate transfer belt is rotated, it is possible to eliminate the rotation and perform appropriate control. An object of the present invention is to provide a possible image forming apparatus, an image forming method, and a semiconductor device.

  In order to achieve the above object, the present invention has the following configuration.

  The present invention provides an image forming apparatus including: a first roller that drives an intermediate transfer belt; a first motor that rotates the first roller; and a speed detection unit that detects a rotation speed of the first rotating body. In the apparatus, the apparatus includes: a rotation determination unit that determines whether rotation of the intermediate transfer belt has occurred; and a control unit that performs control for canceling the rotation of the intermediate transfer belt. Torque command value determining means for determining whether or not the torque command value for the first motor is a preset minimum value, and the rotational speed of the first rotating body detected by the speed detecting means is preset. Speed determining means for determining whether or not the set target value is exceeded, the torque command value determining means determines that the torque command value is the minimum value, and the speed determining means determines the first value. When the rotational speed of the rotary body is determined to exceed the target value, and the determined structure and accompanying rotation of the intermediate transfer belt occurs.

  According to this configuration, when the intermediate transfer belt is rotated, it is possible to cancel the rotation and perform appropriate control.

  Further, the image forming apparatus of the present invention has a second rotating body that conveys the recording paper, and the control means is a speed difference between a surface speed of the intermediate transfer belt and a peripheral speed of the second rotating body. It may be a speed control means for controlling the rotational speed of the second rotating body so that is within a predetermined range.

  According to this configuration, the influence of the speed difference between the intermediate transfer belt and the peripheral speed of the second rotating body can be kept within an allowable range.

  The speed control means is a correction speed calculation means for calculating a correction speed for correcting the rotation speed of the second rotator based on the rotation speed of the first rotator detected by the speed detector. The rotational speed of the second rotating body may be controlled based on the correction speed calculated by the correction speed calculation means.

  According to this configuration, it is possible to calculate a correction speed for bringing the peripheral speed of the second rotating body close to the target value.

  The image forming apparatus of the present invention further includes a second rotator for transferring the toner image formed on the intermediate transfer belt to a recording paper, and the control means moves the second rotator to the intermediate transfer belt. It may be a movement control means for moving in a direction away from the transfer belt.

  According to such a configuration, it is possible to reduce the pressure at the contact portion between the second rotating body and the intermediate transfer belt and to eliminate the accompanying rotation.

  The movement control means includes distance calculation means for calculating a distance to move the second rotating body based on the rotation speed of the first rotating body detected by the speed detecting means, and the distance calculation The movement of the second rotating body may be controlled based on the distance calculated by the means.

  According to such a configuration, the second rotating body can be moved by a distance necessary to eliminate the accompanying rotation.

  Further, the image forming apparatus of the present invention is characterized in that the image forming apparatus of the present invention includes a second rotating body for transferring the toner image formed on the intermediate transfer belt to a recording sheet, and the intermediate transfer belt via the intermediate transfer belt. A third rotating body located opposite to the second rotating body, and the control means is a movement control means for moving the third rotating body in a direction away from the intermediate transfer belt. Also good.

  According to such a configuration, by moving the third rotating body, the pressure at the contact portion between the second rotating body and the intermediate transfer belt can be reduced, and the accompanying rotation can be eliminated.

  The movement control means includes distance calculation means for calculating a distance for moving the third rotating body based on the rotation speed of the first rotating body detected by the speed detecting means, and the distance calculation The movement of the third rotating body may be controlled based on the distance calculated by the means.

  According to such a configuration, the third rotating body can be moved by a distance necessary to eliminate the accompanying rotation.

  The second rotating body may be a secondary transfer roller for transferring a toner image formed on the intermediate transfer belt to the recording paper.

  According to this configuration, it is possible to eliminate the accompanying rotation caused by the secondary transfer roller.

  The second rotating body may be a registration roller that conveys the recording paper.

  According to such a configuration, the accompanying rotation caused by the registration roller can be eliminated.

  The image forming apparatus of the present invention further includes PWM control means for controlling the first motor, and the torque command value determination means determines whether or not the current command value supplied to the PWM control means is a minimum value. It is good also as a structure which determines these.

  According to such a configuration, the present invention can be applied when a brushless motor is used as the motor of the image forming apparatus.

  The image forming apparatus of the present invention further includes a current detection unit that detects a current value for driving the first motor, and the torque command value determination unit has a minimum current value supplied to the current detection unit. It is good also as a structure which determines whether it is.

  According to such a configuration, it is possible to determine the follow-up using the first motor drive current.

  The present invention conveys a first rotating body that drives an intermediate transfer belt, a first motor that rotates the first rotating body, and a recording sheet onto which a toner image formed on the intermediate transfer belt is transferred. In the image forming apparatus having the second rotating body for performing, a speed detecting means for detecting the rotational speed of the first rotating body, a current value detecting means for detecting the current value of the first motor, A rotation determining unit that determines whether or not the intermediate transfer belt is rotated; and a control unit that performs control for eliminating the rotation of the intermediate transfer belt. Determines that rotation of the intermediate transfer belt is occurring when the current value detected by the current value detection means is smaller than a preset target value, and the control means uses the speed detection means. Detected It was based on the rotation speed of the first rotating body, and configured to be the second speed control means for performing control to slow down the rotational speed of the rotating body.

  According to this configuration, when the intermediate transfer belt is rotated, it is possible to cancel the rotation and perform appropriate control.

The present invention includes a first rotating body that drives the intermediate transfer belt, a speed detection device that detects a rotation speed of the first rotating body, and a first motor that rotates the first rotating body. In the image forming method by the image forming apparatus, a speed detection procedure for detecting a rotation speed of the first rotating body, a follow-up determination procedure for determining whether or not the intermediate transfer belt is swung, and A control procedure for performing control for eliminating the accompanying rotation of the intermediate transfer belt,
The follow-up determination procedure includes a torque command value determination procedure for determining whether or not a torque command value for the first motor is a preset minimum value, and the first command detected by the speed detection device. A speed determination procedure for determining whether or not the rotational speed of the rotating body exceeds a preset target value, wherein the torque command value is determined to be the minimum value by the torque command value determination procedure, and When it is determined by the speed determination procedure that the rotation speed of the first rotating body exceeds the target value, it is determined that the accompanying rotation of the intermediate transfer belt has occurred.

  According to this method, when the intermediate transfer belt is rotated, it is possible to cancel the rotation and perform appropriate control.

  The present invention provides a semiconductor device mounted on an image forming apparatus having a first rotating body that drives an intermediate transfer belt and a first motor that rotates the first rotating body. A speed detecting means for detecting the rotational speed of the intermediate transfer belt, a follow-up judging means for judging whether or not the intermediate transfer belt is accompanied, and a control for performing control for canceling the accompanying rotation of the intermediate transfer belt. The rotation determining means is detected by the torque command value determining means for determining whether or not the torque command value for the first motor is a preset minimum value, and detected by the speed detecting means. Speed determining means for determining whether or not the rotational speed of the first rotating body is higher than a preset target value, and the torque command value is determined to be the minimum value by the torque command value determining means. Ah Is determined, and when the rotational speed of the first rotating body is determined to exceed the target value by said speed determination means, and the determining arrangement and accompanying rotation of the intermediate transfer belt occurs.

  According to this configuration, when the intermediate transfer belt is rotated, it is possible to cancel the rotation and perform appropriate control.

  According to the present invention, when accompanying rotation of the intermediate transfer belt occurs, the accompanying rotation is eliminated so that appropriate control can be performed.

The image forming apparatus according to the present invention includes a follow-up determination unit that determines whether or not the intermediate transfer belt is rotated based on a torque command value for the intermediate transfer drive motor and a rotation speed of the intermediate transfer drive motor. Control means for performing control for eliminating rotation, and when rotation occurs, the rotation is canceled so that appropriate speed control can be performed.
(First embodiment)
A first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram illustrating an overview of the entire image forming apparatus 100 according to the first embodiment.

  The image forming apparatus 100 and the scanning unit 10 scan the document while irradiating the document with a light source, and read the reflected light from the document with a 3-line CCD (Charge Coupled Device) sensor. The read image is subjected to image processing such as scanner γ correction, color conversion, image separation, and gradation correction processing by the image processing unit, and then sent to the image writing unit 20. The image writing unit 20 modulates the driving of an LD (Laser Diode) according to the image data. In the photoconductor unit 30, an electrostatic latent image is written by a laser beam from the LD on a uniformly charged rotating photoconductor drum 31, and toner is attached by the developing unit 40 to be visualized.

  The toner image formed on the photosensitive drum 31 is transferred onto the intermediate transfer belt 51 of the intermediate transfer unit 50. When full-color copying is performed in the image forming apparatus 100, toner images of four colors (black, cyan, magenta, yellow) are sequentially superimposed on the intermediate transfer belt 51. When image formation and transfer of all colors are completed, the recording paper is fed from the paper feed tray 60 in time with the intermediate transfer belt 51, and the secondary transfer unit 70 simultaneously records four colors from the intermediate transfer belt 51. The toner image is secondarily transferred to the paper. The recording paper on which the toner image has been transferred is sent to the fixing unit 90 through the conveying unit 80, and is discharged after the toner image is fixed on the recording paper by the fixing roller and the pressure roller.

  FIG. 2 is a diagram illustrating the configuration of the intermediate transfer belt 51 of the image forming apparatus 100 according to the first embodiment and the surroundings for driving it.

  The intermediate transfer driving roller 53 is a first rotating body that drives the intermediate transfer belt 51, and the intermediate transfer driving motor 52 is a first motor that rotates the intermediate transfer driving roller 53. The secondary transfer roller 71 is a second rotating body for transferring the toner image on the intermediate transfer belt 51 to the recording paper, and the secondary transfer motor 72 is a second motor for rotating the secondary transfer roller 71. is there.

  In the image forming apparatus 100, the rotation of the intermediate transfer driving motor 52 is transmitted to the intermediate transfer driving roller 53 via the gear, and the intermediate transfer belt 51 is driven by the rotation of the intermediate transfer driving roller 53. The speed control of the intermediate transfer drive motor 52 is performed by feeding back a signal from the encoder 54 provided on the shaft of the intermediate transfer drive roller 53 or a signal obtained by reading the scale provided on the intermediate transfer belt 51 by the scale sensor 55. It is. The scale is a means for measuring the moving distance of the intermediate transfer belt 51 and is attached to the intermediate transfer belt 51. The scale sensor 55 can detect the surface speed of the intermediate transfer belt 51 by reading the scale. In the image forming apparatus 100 of the present embodiment, the signal detected by the scale sensor 55 is fed back.

  When the intermediate transfer belt 51 is driven, the toner image formed on the intermediate transfer belt 51 is conveyed to the pressure contact portion 85 between the intermediate transfer belt 51 and the secondary transfer roller 71. The conveyed toner image is sandwiched by the repulsive roller 73 between the intermediate transfer belt 51 and the secondary transfer roller 71 at the pressure contact portion 85 between the intermediate transfer belt 51 and the secondary transfer roller 71 to sandwich the recording paper. Then, the toner image is secondarily transferred from the intermediate transfer belt 51 to the recording paper.

  FIG. 3 is a circuit block diagram of the image forming apparatus 100 of the first embodiment.

  The image forming apparatus 100 includes a main body control unit 200, a middle transfer drive motor control unit 300, and a secondary transfer motor control unit 400.

  The main body control unit 200 is a control unit that controls the entire image forming apparatus 100, and outputs a speed instruction to the intermediate transfer drive motor control unit 300 and the secondary transfer motor drive unit 400. The intermediate transfer drive motor control unit 300 receives a speed instruction from the main body control unit 200 and controls the drive of the intermediate transfer drive motor 52. Further, the intermediate transfer drive motor controller 300 controls the rotation speed of the intermediate transfer drive motor 52 by feeding back the rotation speed information detected by the scale sensor 55. Further, the intermediate transfer drive motor control unit 300 detects that the PWM value for the intermediate transfer drive motor 52 is minimum.

  The secondary transfer motor control unit 400 controls the drive of the secondary transfer motor 72 in response to a speed instruction from the main body control unit 200. The speed instruction output from the main body control unit 200 to the intermediate transfer drive motor control unit 300 and the secondary transfer motor control unit 400 is sequentially sent by the speed reference clock.

  The image forming apparatus 100 according to the present embodiment determines whether the intermediate transfer belt 51 is rotated based on the rotation speed information detected by the scale sensor 55 and the PWM value for the intermediate transfer drive motor 52. . When it is determined that the accompanying rotation has occurred, control is performed to slow down the rotation of the secondary transfer motor 72 so that the surface speed of the intermediate transfer belt 51 and the peripheral speed of the secondary transfer roller 71 disappear.

  The intermediate transfer drive motor control unit 300 and the secondary transfer motor control unit 400 will be further described below with reference to FIG. FIG. 4 is a circuit configuration diagram of the intermediate transfer drive motor control unit 300 and the secondary transfer motor control unit 400.

  The intermediate transfer drive motor control unit 300 includes gain multipliers 310 and 320, a loop filter 330, a PWM (Pulse Width Modulation) unit 340, a pre-driver 350, and an FET (Field effect transistor) 360. The gain multipliers 310 and 320, the loop filter 330, and the PWM (Pulse Width Modulation) unit 340 according to the present embodiment are integrated to constitute a semiconductor device 370.

  The intermediate transfer drive motor control unit 300 performs gain multiplication by the gain multipliers 310 and 320 on the speed instruction signal from the main body control unit 200, and performs filter processing by the loop filter 330. The filtered signal is converted into a PWM signal by the PWM unit 340 and output to the pre-driver 350. The pre-driver 350 converts the PWM signal into a three-phase output signal and drives the intermediate transfer drive motor 52 via the FET 360. The intermediate transfer drive motor control unit 300 performs control so that the rotation speed of the intermediate transfer drive motor 52 becomes a target value based on the speed instruction signal.

  Here, the PWM unit 340 will be described. The PWM unit 340 of this embodiment includes a PWM value calculation unit 341, a minimum value determination unit 342, and a minimum notification unit 343.

  The PWM value calculation unit 341 calculates a PWM value that is a current command value for determining the duty of the PWM signal output from the PWM unit 340. The PWM unit 340 generates and outputs a PWM signal based on the PWM duty calculated by the PWM value calculation unit 341. The PWM value is a current command value for the intermediate transfer drive motor 52, that is, synonymous with a torque command value for the intermediate transfer drive motor 52.

  The minimum value determination unit 342 determines whether or not the PWM value calculated by the PWM value calculation unit 341 is the minimum value. The minimum value determination unit 342 of the present embodiment may determine that the PWM value is the minimum value when detecting a state where the PWM duty determined by the calculated PWM value is 0% a plurality of times. In addition, the minimum value determination unit 342 according to the present embodiment performs a plurality of times when the PWM duty determined by the calculated PWM value is equal to or less than a value stored in advance in a storage device (not shown) provided in the semiconductor device 370. When detected, the PWM value may be determined to be the minimum value. The PWM duty value stored in advance may be 3%, for example. The PWM duty value may be determined according to the specifications of the semiconductor device 370.

  When it is determined that the PWM value is the minimum value, the minimum notification unit 343 notifies the secondary transfer motor control unit 400 that the PWM value is the minimum value.

  The secondary transfer motor control unit 400 includes gain multipliers 410 and 420, a loop filter 430, a PWM unit 440, a pre-driver 450, an FET 460, a follow-up determination unit 470, and a speed control unit 480.

  The processing by the gain multipliers 410 and 420, the loop filter 430, the PWM unit 440, the pre-driver 450, and the FET 460 is the same as the processing by the intermediate transfer drive motor control unit 300. The gain multipliers 410 and 420, the loop filter 430, the PWM unit 440, the accompanying determination unit 470, and the speed control unit 480 are integrated to constitute a semiconductor device 490.

  The secondary transfer motor control unit 400 according to the present embodiment determines whether or not the intermediate transfer belt 51 is rotated by the secondary transfer roller 71 by the rotation determination unit 470, and the rotation is generated. Is determined, the speed controller 480 controls the rotational speed of the secondary transfer motor 72. Hereinafter, the accompanying determination unit 470 and the speed control unit 480 will be described.

  The accompanying determination unit 470 includes a minimum notification acquisition unit 471 and a speed determination unit 472. The minimum notification acquisition unit 471 receives a notification indicating that the PWM value from the minimum notification unit 342 is the minimum value, and issues a speed determination instruction to the speed determination unit 472. The speed determination unit 472 receives the speed determination instruction, acquires the rotation speed information of the intermediate transfer drive motor 52 detected from the scale sensor 55, and determines whether or not the rotation speed of the intermediate transfer drive motor 52 exceeds the target value. Determine. The target value of the rotational speed may be the rotational speed indicated by the speed instruction value from the main body control unit 200, or may be stored in advance in a storage device (not shown) included in the semiconductor device 490.

  The speed control unit 480 is a means for canceling the accompanying rotation, and when the accompanying determination unit 470 determines that the accompanying rotation has occurred, the peripheral speed of the secondary transfer roller 71 to cancel the accompanying rotation. Control. That is, the speed controller 480 controls the driving of the secondary transfer motor 72 that rotates the secondary transfer roller 71.

  The speed control unit 480 includes a corrected speed calculation unit 481 and a speed instruction output unit 482. The correction speed calculation unit 481 calculates a correction speed of the secondary transfer motor 72 for making the peripheral speed of the secondary transfer roller 71 equal to the surface speed of the intermediate transfer belt 51. Details of the correction speed calculation processing will be described later. The speed instruction output unit 482 outputs the corrected speed calculated by the corrected speed calculator 481 as a speed instruction value.

  Note that it is difficult to make the surface speed of the intermediate transfer belt 51 and the peripheral speed of the secondary transfer roller 71 completely constant due to various influences of peripheral mechanisms of the intermediate transfer belt 51 and the secondary transfer roller 71. . Therefore, in the image forming apparatus 100 of the present embodiment, the peripheral speed of the secondary transfer roller 71 is controlled so that the speed difference between the surface speed of the intermediate transfer belt 51 and the peripheral speed of the secondary transfer roller 71 is within a predetermined range. To do. The predetermined range is a range determined in advance based on experimental values.

  Next, the operation of the image forming apparatus 100 will be described with reference to FIGS.

  FIG. 5 is a flowchart for explaining the operation of the intermediate drive motor control unit 300 of the image forming apparatus 100 according to the first embodiment.

  When the image forming apparatus 100 receives the operation instruction, the process proceeds to step S 51, and the intermediate transfer drive motor 52 is driven by the intermediate transfer drive motor control unit 300. Progressing to step S52 following step S51, the rotation speed information of the intermediate transfer drive motor is detected by the scale sensor 55. Progressing to step S53 following step S52, the intermediate transfer drive motor controller 300 adjusts the rotational speed of the intermediate transfer drive motor 52 based on the acquired rotational speed information.

  Progressing to step S54 following step S53, the PWM unit 340 determines whether or not the PWM value calculated by the PWM unit 340 is the minimum value. More specifically, in the PWM unit 340, the PWM value calculation unit 341 calculates a PWM value for generating a PWM signal. The minimum value determination unit 342 determines whether or not the PWM value calculated by the PWM value calculation unit 341 is a minimum value. The determination process by the minimum value determination unit 342 is as described above.

  Progressing to step S55 following step S54, if the minimum value determination unit 342 determines that the PWM value is the minimum value, the minimum notification unit 343 indicates that the PWM value is the minimum value, and the secondary transfer motor control unit 400. To notify. More specifically, the minimum notification unit 343 notifies the semiconductor device 490 that the minimum notification unit 343 has a minimum PWM value.

  Next, the operation of the secondary transfer motor control unit 400 will be described with reference to FIG. FIG. 6 is a flowchart for explaining the operation of the secondary transfer motor control unit 400 of the image forming apparatus 100 according to the first embodiment.

  When the image forming apparatus 100 receives an operation instruction, the process proceeds to step S61, where the secondary transfer motor 72 is driven by the secondary transfer motor control unit 400. Following step S61, the process proceeds to step 62, where the secondary transfer motor control unit 400 uses the rotation angle detected by the Hall element 74 (see FIG. 4) and the frequency generator (hereinafter referred to as FG) 75 (see FIG. 4). The rotational speed of the secondary transfer motor 52 is adjusted using the detected rotational speed.

  Progressing to step S63 following step S62, the follow-up determination unit 470 determines whether the minimum notification acquisition unit 471 has received a notification indicating that the PWM value for the intermediate transfer drive motor 52 is the minimum value. Progressing to step S64 following step S63, when the minimum notification unit 471 receives a notification that the PWM value is the minimum value, the follow-up determination unit 470 causes the speed determination unit 472 to perform the intermediate transfer drive motor using the encoder 54 and the scale sensor 55. Get the rotation speed information. Then, the accompanying determination unit 470 determines whether or not the rotation speed of the intermediate transfer drive motor 52 exceeds the target value by the speed determination unit 472. When the speed determination unit 472 determines that the rotation speed of the intermediate transfer drive motor 52 exceeds the target value, the accompanying determination unit 470 determines that the intermediate transfer belt 51 is rotated by the secondary transfer roller 71. Then, a speed control instruction for the secondary transfer motor 72 is issued to the speed controller 480.

  Progressing to step S65 following step S64, the speed control unit 280 receives the speed control instruction and controls the rotational speed of the secondary transfer motor 72, and changes the peripheral speed of the secondary transfer roller 71 to the surface speed of the intermediate transfer belt 51. Move closer to.

  More specifically, the speed control unit 280 calculates a correction speed X for reducing the rotation speed of the secondary transfer roller 71 by the correction speed calculation unit 281. The speed instruction output unit 282 converts the calculated corrected speed X into a speed instruction value and outputs it.

  Here, the calculation process of the correction speed X by the correction speed calculation part 281 is demonstrated.

  In the present embodiment, the correction speed calculation unit 281 calculates the correction speed X using the rotation speed information of the intermediate transfer drive motor 52 acquired by the speed determination unit 272.

  In this embodiment, the case where the target value of the surface speed of the intermediate transfer belt 51 is 200 mm / s and the roller diameter of the secondary transfer roller 71 is 10 mm will be described. In the following description, the surface speed of the intermediate transfer belt 51 and the rotation speed of the intermediate transfer drive motor 52 are assumed to be constant.

  The surface speed V of the intermediate transfer belt 51 is V = rω = r × 2πf where r is the diameter of the secondary transfer roller 71 and f is the rotational frequency of the secondary transfer roller 71. From this relationship, when the target value of the surface speed of the intermediate transfer belt 51 is 200 mm / s and the roller diameter of the secondary transfer roller 71 is 10 mm, the rotational frequency f of the secondary transfer roller 71 is 3.18 Hz. Therefore, the speed instruction value supplied from the main body control unit 200 to the secondary transfer motor control unit 400 is a value for setting the rotation frequency of the secondary transfer motor 72 to 3.18 Hz.

  When the secondary transfer motor 72 is driven by this speed instruction value, the minimum value determination unit 342 determines that the PWM value calculated by the PWM unit 340 is the minimum value, and the rotation of the intermediate transfer drive motor 52 When the speed is 201 mm / s (when exceeding the target value), the roller diameter of the secondary transfer roller is r = V / 2πf = 201 / (2π × 3.18) = 10.06 mm. From this result, it can be seen that the diameter of the secondary transfer roller 71 is expanded by 0.06 mm, and the peripheral speed of the secondary transfer roller is 1 mm / s faster than the target value due to this expansion. Therefore, the correction speed X calculated by the correction speed calculation unit 481 is 1 mm / s.

  In this state, the rotation frequency f of the intermediate transfer driving motor 52 for setting the surface speed of the intermediate transfer belt 51 to the target value of 200 mm / s is f = V / 2πr = 200 / (2 × π × 10.06) = 3.16 Hz. Therefore, the speed instruction output unit 482 may output an instruction value for lowering the rotation frequency of the secondary transfer roller 71 by 0.02 Hz as a speed instruction value for adjusting the rotation speed of the secondary transfer roller 71 to the target value.

  As described above, according to the present embodiment, it is determined whether or not the intermediate transfer belt 51 is rotated. When the accompanying rotation occurs, the rotational speed of the secondary transfer roller 71 is controlled so that the surface speed of the intermediate transfer belt 51 and the peripheral speed of the secondary transfer roller 71 are equal. This eliminates the accompanying state. Therefore, according to the present embodiment, even when the intermediate transfer belt 51 is rotated, it is possible to eliminate the rotation and perform appropriate control.

In the present embodiment, the second rotating body has been described as the secondary transfer roller. However, the speed control described in the present embodiment is also applicable to the case where the second rotating body is the secondary transfer belt. . When the second rotator is a secondary transfer belt, the speed controller rotates the roller that rotates the secondary transfer belt so that the surface speed of the intermediate transfer belt and the secondary transfer belt are within a predetermined range. Adjust the speed.
(Second embodiment)
A second embodiment of the present invention will be described below with reference to the drawings. The second embodiment is different from the first embodiment only in that the accompanying determination unit 470 is provided on the intermediate transfer drive motor controller 300A side. Therefore, in the following description of the present embodiment, only differences from the first embodiment will be described, and the reference numerals used in the description of the first embodiment will be used for those having the same functional configuration as the first embodiment. The same code | symbol is provided and the description is abbreviate | omitted.

  FIG. 7 is a functional configuration diagram of the image forming apparatus 100A according to the second embodiment.

  The image forming apparatus 100A includes a follow-up determination unit 470 in addition to the components included in the image forming apparatus 100 of the first embodiment. In the image forming apparatus 100A, the gain multipliers 310 and 320, the loop filter 330, the PWM unit 340, and the accompanying determination unit 470 may be integrated to constitute the semiconductor device 370A.

  The operation of the image forming apparatus 100A according to the present embodiment will be described below with reference to FIGS.

  FIG. 8 is a flowchart for explaining the operation of the intermediate drive motor control unit 300A of the image forming apparatus 100A of the second embodiment.

  The processing from step S81 to step S84 in FIG. 8 is the same as the processing from step S51 to step S54 in FIG.

  In step S <b> 84, when the minimum value determination unit 342 of the PWM unit 340 determines that the PWM value calculated by the PWM value calculation unit 341 is the minimum value, the minimum notification unit 343 sends the PWM value to the accompanying determination unit 470. Notify that it is the minimum value. Progressing to step S85 following step S84, when the minimum notification acquisition unit 471 receives a notification that the PWM value is the minimum value, the rotation determination unit 470 acquires the speed determination unit 272 and rotates the intermediate transfer drive motor 52. It is determined whether the speed exceeds the target value.

  If it is determined in step S85 that the rotation speed of the intermediate transfer drive motor 52 exceeds the target value, the accompanying determination unit 470 determines that the intermediate transfer belt 51 is being rotated by the secondary transfer roller 71. Then, a speed control instruction is issued to the secondary transfer motor control unit 400A. The secondary transfer motor control unit 400A receives the speed control instruction from the follow-up determination unit 470 and starts controlling the rotation speed of the secondary transfer roller 71.

  Next, the operation of the secondary transfer motor control unit 400A will be described with reference to FIG. FIG. 9 is a flowchart for explaining the operation of the secondary transfer motor control unit 400A of the image forming apparatus 100A of the second embodiment.

  The processing in step S91 and step S92 in FIG. 9 is the same as the processing in step S61 and step S62 in FIG.

  Progressing to step S93 following step S92, the speed control unit 480 determines whether or not a speed control instruction has been received. When the speed control unit 480 receives a speed control instruction from the follow-up determination unit 470 of the intermediate transfer drive motor control unit 300A, the speed control unit 480 proceeds to step S94, controls the rotational speed of the secondary transfer motor 72, and controls the secondary transfer roller 71. And the surface speed of the intermediate transfer belt 51 are made closer to each other.

  Details of the process of step S94 are the same as the process of step S65 of FIG.

  As described above, in this embodiment, the accompanying rotation determination unit 470 is provided in the intermediate transfer drive motor control unit 300A so that the determination of the accompanying operation is performed on the intermediate transfer drive motor control unit 300A side. Therefore, in this embodiment, it is not necessary to send the signal detected by the scale sensor 55 to both the intermediate transfer drive motor control unit 300A and the secondary transfer motor control unit 400A. Therefore, the wiring around the intermediate transfer drive motor control unit 300A and the secondary transfer motor control unit 400A can be simplified.

In this embodiment, it is determined whether or not the intermediate transfer belt 51 has been rotated. When it is determined that the rotation has occurred, the rotational speed of the secondary transfer motor 72 is controlled to rotate the intermediate transfer belt 51. Eliminate. Therefore, according to the present embodiment, when the intermediate transfer belt 51 is rotated, it is possible to cancel the rotation and perform appropriate control.
(Third embodiment)
A third embodiment of the present invention will be described below with reference to the drawings. The third embodiment is different from the first embodiment in that the accompanying movement is eliminated by moving the secondary transfer roller 71 away from the intermediate transfer belt 51. Therefore, in the following description of the present embodiment, only differences from the first embodiment will be described, and the reference numerals used in the description of the first embodiment will be used for those having the same functional configuration as the first embodiment. The same code | symbol is provided and the description is abbreviate | omitted.

  FIG. 10 is a diagram illustrating a state in which the intermediate transfer belt 51 and the secondary transfer roller 71 are in pressure contact with each other in the image forming apparatus 100B of the third embodiment.

  In the image forming apparatus 100B, as shown in FIG. 10, when the secondary transfer roller 71 and the intermediate transfer belt 51 are always in contact with each other, the intermediate transfer belt 51 is bent at the press contact portion 85, and the intermediate transfer belt 51 is bent. It may be in a state of being stuck. Deflection of the intermediate transfer belt 51 is not preferable because it adversely affects the transferred image when the toner image is transferred.

  Therefore, in the image forming apparatus 100B of the present embodiment, in order to solve this problem, the secondary transfer roller 71 and the intermediate transfer belt 51 are not in contact with each other when the image forming apparatus 100B is not operating. 71 is separated from the intermediate transfer belt 51. When the image forming apparatus 100B receives the operation instruction, the secondary transfer roller 71 and the intermediate transfer belt 51 are pressed against each other so that the state shown in FIG.

  The secondary transfer roller 71 is separated from the intermediate transfer belt 51 by the cam 82 and the moving motor 84. The secondary transfer roller 71 is pressed against the intermediate transfer belt 51 by a cam 82 and a moving motor 84. In the image forming apparatus 100B, the movement motor 84 is driven, and the operation of the movement motor 84 is transmitted to the secondary transfer roller 71 via the cam 82, whereby the secondary transfer roller 71 is brought into pressure contact with the intermediate transfer belt 51. The secondary transfer roller 71 is separated from the intermediate transfer belt 51. This configuration is generally used in a conventional image forming apparatus.

  When the roller diameter of the secondary transfer roller 71 expands, the peripheral speed of the secondary transfer roller 71 increases, and the contact pressure between the intermediate transfer belt 51 and the secondary transfer roller 71 at the press contact portion 85 increases. When the contact pressure increases, the friction between the intermediate transfer belt 51 and the secondary transfer roller 71 at the pressure contact portion 85 increases, and the intermediate transfer belt 51 is more easily rotated by this friction. The contact pressure is a pressure at which the secondary transfer roller 71 is pressed against the intermediate transfer belt 51.

  Therefore, in the present embodiment, when the intermediate transfer belt 51 is rotated by the secondary transfer roller 71 in the image forming apparatus 100B, the secondary transfer roller 71 is moved away from the intermediate transfer belt 51. Then, by reducing the contact pressure between the intermediate transfer belt 51 and the secondary transfer roller 71 at the press contact portion 85, the accompanying rotation is eliminated.

  The functional configuration of the image forming apparatus 100B according to this embodiment will be described below. FIG. 11 is a functional configuration diagram of the image forming apparatus 100B according to the third embodiment.

  The image forming apparatus 100B includes a main body control unit 200A, a middle transfer drive motor control unit 300, and a secondary transfer motor control unit 400B.

  The main body control unit 200A includes a follow-up determination unit 470A and a movement control unit 210. The accompanying determination unit 470A of the present embodiment includes a minimum notification acquisition unit 471A and a speed determination unit 472A. When the speed determination unit 472A determines that the rotation speed of the intermediate transfer drive motor 52 exceeds the target value and the minimum notification acquisition unit 471A acquires a notification that the PWM value is the minimum value, the rotation determination unit 470A It is determined that turning has occurred. The order of determination in the present embodiment is not limited to the above order. In the present embodiment, when the PWM value is finally the minimum value and the rotation speed of the intermediate transfer drive motor 52 exceeds the target value, it is determined that the rotation is accompanied. Therefore, in the present embodiment, as in the first and second embodiments, the rotational speed of the intermediate transfer drive motor 52 may be determined after determining whether or not the PWM value is the minimum value.

  The main body control unit 200 </ b> A acquires rotation speed information of the intermediate transfer drive motor 52 detected by the scale sensor 55. The speed determination unit 472A compares the acquired rotation speed information with the target value of the rotation speed of the intermediate transfer drive motor 52 corresponding to the speed instruction value from the main body control unit 200A. Then, the speed determination unit 472 determines whether or not the rotation speed of the intermediate transfer drive motor 52 exceeds the target value. If it is determined that the rotation speed of the intermediate transfer drive motor 52 exceeds the target value, the minimum notification acquisition unit 471A has received a notification that the PWM value is the minimum value from the PWM unit 340 of the intermediate transfer drive motor control unit 300. It is determined whether or not, and if a notification has been given, this notification is acquired.

  The movement control unit 210 is a follow-up canceling unit in the present embodiment. The movement control unit 210 includes a movement distance calculation unit 211. The movement control unit 210 controls the drive of the movement motor 84 to move the secondary transfer roller 71 and adjusts the contact pressure of the secondary transfer roller 71 with respect to the intermediate transfer belt 51. The contact pressure increases when the secondary transfer roller 71 is moved in a direction to approach the intermediate transfer belt 51. Further, the contact pressure decreases when the secondary transfer roller 71 is moved away from the intermediate transfer belt 51. If the contact pressure is reduced, the friction between the intermediate transfer belt 51 and the secondary transfer roller 71 at the pressure contact portion 85 is reduced, and the accompanying rotation is eliminated. Therefore, the intermediate transfer belt 51 is controlled by the intermediate transfer drive motor control unit 300. Can be driven according to

  The movement distance calculation unit 211 calculates a movement distance for moving the secondary transfer roller 71 by the movement motor 84. Details of the movement distance calculation processing by the movement distance calculation unit 211 will be described later.

  The intermediate transfer drive motor control unit 300 is as described in the first embodiment. The intermediate transfer drive motor control unit 300 includes a PWM unit 340 that determines and notifies whether the PWM value is the minimum value. The secondary transfer motor control unit 400B includes gain multipliers 410 and 420, a loop filter 430, a PWM unit 440, a pre-driver 450, and an FET 460, and controls driving of the secondary transfer motor 72.

  The operation of the image forming apparatus 100B of this embodiment will be described below with reference to FIG. FIG. 12 is a flowchart for explaining the operation of the image forming apparatus 100B of the third embodiment.

  When the image forming apparatus 100B receives an operation instruction, the process proceeds to step S1201, where the intermediate transfer drive motor control unit 300 drives the intermediate transfer drive motor 72, and the secondary transfer motor control unit 400B drives the secondary transfer motor 72.

  Progressing to step S1202 following step S1201, the moving motor 84 is driven to bring the secondary transfer roller 71 into contact with the intermediate transfer belt 51 via the cam 82. Proceeding to step S1203 following step S1202, the main body control unit 200A acquires rotation speed information of the intermediate transfer drive motor 52 detected from the scale sensor 55.

  Progressing to step S1204 following step S1203, the intermediate transfer drive motor controller 300 also acquires rotational speed information of the intermediate transfer drive motor 52 detected from the scale sensor 55, and the intermediate transfer drive motor 52 is acquired based on the acquired rotational speed information. To control the rotation speed. Progressing to step S1205 following step S1204, the speed determination unit 472A of the follow-up determination unit 470A determines whether or not the rotation speed of the intermediate transfer drive motor 52 exceeds the target value based on the rotation speed information acquired in step S1204. Determine.

  When the rotation speed of the intermediate transfer drive motor 52 exceeds the target value, the process proceeds to step S1206 following step S1205, and the intermediate transfer drive motor control unit 300 decreases the PWM value for the intermediate transfer drive motor 52 to reduce the intermediate transfer drive motor. Control is performed to reduce the rotational speed of 52. Progressing to step S1207 following step S1206, in the PWM unit 340 of the intermediate transfer drive motor control unit 300, the minimum value determination unit 342 determines whether or not the PWM value calculated by the PWM value calculation unit 341 is the minimum value. judge.

  If the PWM value is the minimum value in step S1207, the process proceeds to step S1208, and the minimum notification unit 343 sends a notification that the PWM value is the minimum value to the main body control unit 200A. In the main body control unit 200A, the follow-up determination unit 470A receives a notification that the PWM value is the minimum value from the minimum notification acquisition unit 471A, and instructs the movement control unit 210 to move the secondary transfer roller 71.

  In response to a movement control instruction for the secondary transfer roller 71, the movement control unit 210 performs control to move the secondary transfer roller 71 in a direction away from the intermediate transfer belt 51. More specifically, the movement control unit 210 calculates the movement distance of the secondary transfer roller 71 by the movement distance calculation unit 211. Then, the movement control unit 210 causes the movement motor 84 to move in the direction away from the secondary transfer roller 71 intermediate transfer belt 51 by the calculated distance.

  The movement distance calculation processing by the movement distance calculation unit 211 will be described below. The movement distance calculation unit 211 according to the present embodiment calculates the same distance as the movement distance of the secondary transfer roller 71 as the roller diameter of the secondary transfer roller 71 is expanded.

  In this embodiment, the case where the target value of the surface speed of the intermediate transfer belt 51 is 200 mm / s and the roller diameter of the secondary transfer roller 71 is 10 mm will be described. In the following description, the surface speed of the intermediate transfer belt 51 and the rotation speed of the intermediate transfer drive motor 52 are assumed to be constant.

  The surface speed V of the intermediate transfer belt 51 is V = rω = r × 2πf where r is the diameter of the secondary transfer roller 71 and f is the rotational frequency of the secondary transfer roller 71. From this relationship, when the target value of the surface speed of the intermediate transfer belt 51 is 200 mm / s and the roller diameter of the secondary transfer roller 71 is 10 mm, the rotational frequency f of the secondary transfer roller 71 is 3.18 Hz. Therefore, the speed instruction value supplied from the main body control unit 200A to the secondary transfer motor control unit 400B is a value for setting the rotation frequency of the secondary transfer motor 72 to 3.18 Hz.

  When the secondary transfer motor 72 is driven by this speed instruction value, the rotational speed of the intermediate transfer drive motor 52 is 201 mm / s (when exceeding the target value), and the minimum value determination unit 342 causes the PWM unit 340 to rotate. When it is determined that the PWM value calculated in (2) is the minimum value, the roller diameter of the secondary transfer roller is r = V / 2πf = 201 / (2π × 3.18) = 10.06 mm. From this result, it can be seen that the diameter of the secondary transfer roller 71 is expanded by 0.06 mm. Therefore, the movement distance calculation unit 211 sets the movement distance of the secondary transfer roller 71 to 0.06 mm. The movement control unit 210 drives the movement motor 84 so as to move the secondary transfer roller 71 away from the intermediate transfer belt 51 by the calculated movement distance.

As described above, in this embodiment, the secondary transfer roller 71 is moved in the direction away from the intermediate transfer belt 51 by the amount of the roller diameter expanded, thereby causing the intermediate transfer generated by the expansion of the roller diameter of the secondary transfer roller 71. The accompanying rotation of the belt 51 can be eliminated. Therefore, according to the present embodiment, when the intermediate transfer belt 51 is rotated, it is possible to cancel the rotation and perform appropriate control.
(Fourth embodiment)
Hereinafter, a fourth embodiment of the present invention will be described with reference to the drawings. The fourth embodiment is a modification of the third embodiment. Therefore, in the following description of the present embodiment, only differences from the third embodiment will be described, and the same reference numerals used in the description of the third embodiment will be used for those having the same functional configuration as the third embodiment. The same code | symbol is provided and the description is abbreviate | omitted.

  In the image forming apparatus 100 </ b> C of the present embodiment, the intermediate transfer belt 51 is rotated by moving the repulsive roller 73 that presses the intermediate transfer belt 51 and the secondary transfer roller 71 away from the secondary transfer roller 71. Eliminate. The repulsive roller 73 is a third roller disposed at a position facing the secondary transfer roller 71 through the intermediate transfer belt 51 in the image forming apparatus 100C of the present invention.

  FIG. 13 is a diagram illustrating a state in which the intermediate transfer belt 51 and the secondary transfer roller 71 are pressed against each other in the image forming apparatus 100 </ b> C according to the fourth embodiment.

  In the image forming apparatus 100C of the present embodiment, the repulsion roller 73 is moved closer to the secondary transfer roller 71 by driving the movement motor 84A and transmitting the operation of the movement motor 84A to the repulsion roller 73 via the cam 82A. The transfer belt 51 and the secondary transfer roller 71 are pressed against each other. Further, the repulsion roller 73 is moved away from the secondary transfer roller 71 by the moving motor 84A and the cam 82A, and the intermediate transfer belt 51 and the secondary transfer roller 71 are separated. This configuration is generally used in a conventional image forming apparatus.

  Next, a functional configuration of the image forming apparatus 100C according to the present embodiment will be described. FIG. 14 is a functional configuration diagram of an image forming apparatus 100C according to the fourth embodiment.

  This embodiment is different from the third embodiment only in that the control target in the movement control unit 210A provided in the main body control unit 200B is the repulsive roller 73. Therefore, in the following description, only differences from the third embodiment will be described.

  The movement control unit 210A included in the main body control unit 200B is a follow-up canceling unit in the present embodiment. The movement control unit 210 </ b> A controls the driving of the movement motor 84 </ b> A to move the repulsive roller 73 and adjusts the contact pressure of the secondary transfer roller 71 against the intermediate transfer belt 51.

  The contact pressure of the secondary transfer roller 71 with respect to the intermediate transfer belt 51 increases when the repulsive roller 73 is moved in a direction to approach the secondary transfer roller 71. The contact pressure decreases when the repulsive roller 73 is moved away from the secondary transfer roller 71. When the contact pressure is reduced, the friction between the intermediate transfer belt 51 and the secondary transfer roller 71 at the pressure contact portion 85 is reduced, and the intermediate transfer belt 51 can be driven according to the control of the intermediate transfer drive motor control unit 300. Therefore, the accompanying rotation of the intermediate transfer belt 51 can be eliminated.

  The moving distance calculation unit 211A calculates a moving distance for moving the repulsive roller 73 by the moving motor 84A.

  Hereinafter, the operation of the image forming apparatus 100C according to the present embodiment will be described with reference to FIG. FIG. 15 is a flowchart for explaining the operation of the image forming apparatus 100C according to the fourth embodiment.

  The processing from step S1501 to step S1507 in FIG. 15 is the same as the processing from step S1201 to step S1207 in FIG. 12 described in the third embodiment, and thus description thereof is omitted.

  When a movement instruction is issued from the accompanying determination unit 470A in step S1507, the process proceeds to step S1508, and the movement control unit 210A and the repulsive roller 73 are controlled to move. More specifically, the movement distance calculation unit 211A calculates the movement distance of the repulsive roller 73 using the rotation speed information of the intermediate transfer drive motor 72 acquired in step S1503.

  The movement control unit 210A controls driving of the movement motor 84A so as to move the repulsive roller 73 by the calculated movement distance. The movement distance calculation processing in the movement distance calculation unit 211A is as described in the third embodiment. Therefore, the repulsive roller 73 is moved in a direction away from the secondary transfer roller 71 by the amount of expansion of the diameter of the secondary transfer roller 71.

As described above, in the present embodiment, the repulsive roller 73 is moved away from the secondary transfer roller 71 by the amount that the roller diameter has expanded. Thereby, the contact pressure between the intermediate transfer belt 51 and the secondary transfer roller 71 is reduced, and the friction between the intermediate transfer belt 51 and the secondary transfer roller 71 is reduced. Therefore, the intermediate transfer belt 51 can be driven in accordance with the control of the intermediate transfer drive motor control unit 300, and the accompanying rotation of the intermediate transfer belt 51 caused by the expansion of the roller diameter of the secondary transfer roller 71 can be eliminated. Therefore, according to the present embodiment, when the intermediate transfer belt 51 is rotated, it is possible to cancel the rotation and perform appropriate control.
(Fifth embodiment)
The fifth embodiment of the present invention will be described below with reference to the drawings. The fifth embodiment is a modification of the first embodiment. Therefore, in the following description of the present embodiment, only differences from the first embodiment will be described, and the reference numerals used in the description of the first embodiment will be used for those having the same functional configuration as the first embodiment. The same code | symbol is provided and the description is abbreviate | omitted.

  In the image forming apparatus 100D of the present embodiment, when the peripheral speed of the registration roller that conveys the recording paper fluctuates, the speed fluctuation may spread twice and the intermediate transfer belt 51 may be rotated. Therefore, the image forming apparatus 100 </ b> D of the present embodiment controls the peripheral speed of the registration roller that conveys the recording paper to approach the surface speed of the intermediate transfer belt 51 when the intermediate transfer belt 51 is rotated.

  Hereinafter, the accompanying rotation of the intermediate transfer belt 51 due to the speed fluctuation of the registration roller will be described with reference to FIGS. FIG. 16 is a first diagram for explaining the speed fluctuation of the registration roller, and FIG. 17 is a second diagram for explaining the speed fluctuation of the registration roller.

  As with the secondary transfer roller 71, the registration roller 95 may expand due to an increase in the temperature in the housing or the temperature of the registration roller itself, and the roller diameter may increase. As the roller diameter increases, the peripheral speed of the registration roller 95 varies, and the peripheral speed of the registration roller 95 increases.

  FIG. 16 illustrates a case where the recording paper 97 onto which the toner image is transferred by the secondary transfer unit 70 in the image forming apparatus 100D is plain paper. When the recording paper 97 is plain paper, the speed fluctuation of the peripheral speed of the registration roller 95 is absorbed by the deflection of the recording paper 97 between the registration roller 95 and the press contact portion 85. Therefore, when the recording paper 97 is plain paper, the speed fluctuation of the peripheral speed of the registration roller 95 does not reach the secondary transfer roller 71, and the intermediate transfer belt 51 due to the speed fluctuation of the peripheral speed of the registration roller 95 does not occur.

  FIG. 17 shows a case where the recording paper 97 onto which the toner image is transferred by the secondary transfer unit 70 in the image forming apparatus 100D is a thick paper. When the recording paper 97 is a thick paper, the bending of the recording paper 97 between the registration roller 95 and the press contact portion 85 is small, and the speed fluctuation of the peripheral speed of the registration roller 95 is not absorbed. Therefore, the speed fluctuation of the peripheral speed of the registration roller 95 is transmitted to the secondary transfer roller 71 via the recording paper 97.

  For example, when the peripheral speed of the registration roller 95 increases, the recording paper 97 is conveyed to the press contact portion 85 in accordance with the peripheral speed of the registration roller 95. Since the recording paper 97 is a thick paper, the friction between the intermediate transfer belt 51 and the recording paper 97 at the press contact portion 85 increases. For this reason, the intermediate transfer belt 51 is likely to be accompanied by the recording paper 97 conveyed in accordance with the peripheral speed of the registration roller 95.

  Therefore, the image forming apparatus 100D according to the present embodiment causes the peripheral speed of the registration roller 95 to approach the surface speed of the intermediate transfer belt 51 when the intermediate transfer belt 51 is rotated when the recording paper 97 is a thick sheet. By controlling, it will eliminate the accompanying.

  The image forming apparatus 100D of the present embodiment will be described below.

  FIG. 18 is a diagram illustrating the registration roller 95 of the image forming apparatus 100D according to the fifth embodiment. The registration roller 95 is a fourth roller for conveying the recording paper in the image forming apparatus 100D.

  A registration roller 95 included in the image forming apparatus 100 </ b> D is rotated by a registration motor 96. When the registration motor 96 is driven, the rotation of the registration motor 96 is transmitted to the registration roller 95 via the gear 98 and rotates. The recording paper 97 is conveyed to the press contact portion 85 by a registration roller 95 and a roller 99 disposed at a position facing the registration roller 95.

  Next, a functional configuration of the image forming apparatus 100D of the present embodiment will be described. FIG. 19 is a functional configuration diagram of an image forming apparatus 100D according to the fifth embodiment.

  The image forming apparatus 100D includes a main body control unit 200C and a middle transfer drive motor control unit 300. The main body control unit 200C includes a follow-up determination unit 470, a speed control unit 480A, and a recording paper determination unit 220. The accompanying determination unit 470 is as described in the first embodiment. That is, the follow-up determination unit 470 receives a notification that the PWM value is the minimum value from the PWM unit 340 of the intermediate transfer drive motor control unit 300, and the rotational speed of the intermediate transfer drive motor 52 detected by the scale sensor 55 is the target value. In the case where the intermediate transfer belt 51 is exceeded, it is determined that the accompanying rotation of the intermediate transfer belt 51 has occurred.

  The speed control unit 480A is a follow-up canceling unit in the present embodiment. When the follow-up determination unit 470 determines that the follow-up is occurring, the speed control unit 480A controls the peripheral speed of the registration roller 95 to cancel the follow-up. I do. The speed control unit 480A controls the driving of the registration motor 96 that rotates the registration roller 95.

  The speed control unit 480A includes a corrected speed calculation unit 481A and a speed instruction output unit 482A. The correction speed calculation unit 481A calculates a correction speed for making the peripheral speed of the registration roller 95 equal to the surface speed of the intermediate transfer belt 51. The speed instruction output unit 482A outputs the corrected speed calculated by the corrected speed calculator 481A as a speed instruction value.

  It should be noted that it is difficult to make the surface speed of the intermediate transfer belt 51 and the peripheral speed of the registration roller 95 completely constant due to various influences of peripheral mechanisms of the intermediate transfer belt 51 and the registration roller 95. Therefore, in the image forming apparatus 100D of the present embodiment, the peripheral speed of the registration roller 95 is controlled so that the speed difference between the surface speed of the intermediate transfer belt 51 and the peripheral speed of the registration roller 95 is within a predetermined range. . The predetermined range is a range determined in advance based on experimental values.

  The recording sheet determination unit 220 determines the type of recording sheet that is selected when the image forming apparatus 100D receives an operation instruction (print instruction). The image forming apparatus 100 </ b> D includes a plurality of paper feed trays 60, and the type of recording paper stored in each paper feed tray 60 is set. For example, the image forming apparatus 100 </ b> D may include a correspondence table between each paper feed tray 60 and the type of recording paper stored in each. The recording paper discrimination unit 220 may discriminate the type of recording paper from the paper feed tray 60 selected when the image forming apparatus 100D receives an operation instruction, using an association table.

  The intermediate transfer drive motor control unit 300 is as described in the first embodiment. The intermediate transfer drive motor control unit 300 includes a PWM unit 340 that determines and notifies whether the PWM value is the minimum value.

  The operation of the image forming apparatus 100D of the present embodiment will be described below. FIG. 20 is a flowchart for explaining the operation of the intermediate transfer drive motor controller 300 in the image forming apparatus 100D of the fifth embodiment.

  The processing from step S2001 to step S2004 in FIG. 20 is the same as the processing from step S51 to step S54 in FIG. 5 described in the first embodiment, and thus description thereof is omitted.

  When the minimum value determination unit 342 of the PWM unit 340 determines in step S2004 that the PWM value calculated by the PWM value calculation unit 341 is the minimum value, the process proceeds to step S2005, and the minimum notification unit 343 proceeds to the main body control unit 200C. This notification is output. More specifically, the minimum notification unit 434 outputs a notification that the PWM value is the minimum value to the accompanying determination unit 470 of the main body control unit 200C.

  Next, the operation of the main body control unit 200C of the present embodiment will be described with reference to FIG. FIG. 21 is a flowchart for explaining the operation of the main body control unit 200C in the image forming apparatus 100D of the fifth embodiment.

  When the image forming apparatus 100D receives the operation instruction, the process proceeds to step S2101 where the registration motor 96 is driven and the registration roller 95 rotates.

  The processing in step S2101 and step S2102 is the same as the processing in step S63 and step S64 in FIG.

  If the rotational speed of the intermediate transfer drive motor 52 exceeds the target value in step S2103, the process advances to step S2104, and the recording sheet determination unit 220 determines the type of the selected recording sheet. If the recording paper determined in step S2104 is a thick paper, the process proceeds to step S2105, and the speed control of the registration motor 96 is performed by the speed control unit 480A.

  More specifically, the speed control unit 480A calculates the correction speed of the registration motor 96 by the correction speed calculation unit 481A. Then, the speed instruction output unit 482A outputs the calculated correction speed to the registration motor 96 as a speed instruction value. The correction speed calculation process by the correction speed calculation unit 481A is as described in the first embodiment. That is, the correction speed calculation unit 481A calculates the roller diameter of the registration roller 95 based on the rotation speed of the intermediate transfer drive motor 52 detected by the scale sensor 55. Then, the correction speed calculation unit 481A calculates a correction speed for setting the rotation speed of the registration motor 96 as a target value from the calculated roller diameter. The speed instruction output unit 482A outputs the corrected speed calculated by the corrected speed calculator 481A as a speed instruction value for the registration motor 96.

  As described above, according to the present embodiment, the accompanying rotation of the intermediate transfer belt 51 due to the speed fluctuation of the registration roller 95 can be eliminated. Further, according to the present embodiment, by determining the selected recording sheet, the cause of the accompanying rotation of the intermediate transfer belt 51 can be specified, and the accompanying rotation can be appropriately eliminated.

As described above, according to the present embodiment, when the intermediate transfer belt 51 is rotated, it is possible to eliminate the rotation and perform appropriate control.
(Sixth embodiment)
The sixth embodiment of the present invention will be described below with reference to the drawings. The sixth embodiment is a modification of the fifth embodiment. Therefore, in the following description of the present embodiment, only differences from the fifth embodiment will be described, and reference numerals used in the description of the fifth embodiment will be used for those having the same functional configuration as the fifth embodiment. The same code | symbol is provided and the description is abbreviate | omitted.

  The image forming apparatus 100E of this embodiment is different from that of the fifth embodiment only in that a follow-up determination unit 470 included in the main body control unit 200C of the fifth embodiment is provided in the intermediate transfer drive motor control unit 300A.

  FIG. 22 is a functional configuration diagram of an image forming apparatus 100E according to the sixth embodiment.

  The image forming apparatus 100E according to the present embodiment includes a main body control unit 200D, a middle transfer drive motor control unit 300A, and a recording paper determination unit 220. The main body control unit 200D includes a speed control unit 480A. The speed control unit 480A and the recording paper determination unit 220 are as described in the fifth embodiment. The intermediate drive motor control unit 300A is as described in the second embodiment.

  The operation of the image forming apparatus 100E of this embodiment will be described below.

  FIG. 23 is a flowchart for explaining the operation of the intermediate transfer drive motor control unit 300A in the image forming apparatus 100E of the sixth embodiment.

  The processing from step S2301 to step S2305 in FIG. 23 is the same as the processing from step S81 to step S85 in FIG. 8 described in the second embodiment, and thus description thereof is omitted.

  If the rotational speed of the intermediate transfer drive motor 52 exceeds the target value in step S2305, the process advances to step S2306, and the intermediate transfer drive motor control unit 300A issues a speed control instruction for the registration motor 96 to the main body control unit 200D. More specifically, the follow-up determination unit 470 issues a speed control instruction to the speed control unit 480A of the main body control unit 200D.

  FIG. 24 is a flowchart for explaining the operation of the main body control unit 200D in the image forming apparatus 100E according to the sixth embodiment.

  When the image forming apparatus 100E receives the operation instruction, the process advances to step S2401, and the registration motor 96 is driven to rotate the registration roller 95. Progressing to step S2402 following step S2401, speed controller 480A determines whether a speed control instruction has been received or not. When a speed control instruction is received in step S2402, the process advances to step S2403, and the recording paper determination unit 220 determines the type of recording paper. If the type of recording paper determined by the recording paper determination unit 220 in step S2403 is thick paper, the process advances to step S2404, and the speed control unit 480A controls the speed of the registration motor 96.

  As described above, according to the present embodiment, the accompanying rotation of the intermediate transfer belt 51 due to the speed fluctuation of the registration roller 95 can be eliminated. Further, according to the present embodiment, by determining the selected recording sheet, the cause of the accompanying rotation of the intermediate transfer belt 51 can be specified, and the accompanying rotation can be appropriately eliminated. Furthermore, according to the present embodiment, since the accompanying rotation determination unit 470 is provided in the intermediate transfer drive motor control unit 300A, the signal detected by the scale sensor 55 is transmitted to both the intermediate transfer drive motor control unit 300A and the main body control unit 200D. There is no need to send. Therefore, the wiring around the intermediate transfer drive motor controller 300A and the main body controller 200D can be simplified.

As described above, according to the present embodiment, when the intermediate transfer belt is rotated, it is possible to eliminate the rotation and perform appropriate control.
(Seventh embodiment)
The seventh embodiment of the present invention will be described below with reference to the drawings. The image forming apparatus 100 </ b> F of the present embodiment is different from the fifth embodiment in that it determines whether or not the intermediate transfer belt 51 is accompanied based on the drive current of the intermediate transfer drive motor 52. Therefore, in the following description of the present embodiment, only differences from the fifth embodiment will be described, and the same reference numerals used in the description of the fifth embodiment will be used for those having the same functional configuration as the fifth embodiment. The same reference numerals are given, and the description thereof is omitted.

  FIG. 25 is a functional configuration diagram of an image forming apparatus 100F according to the seventh embodiment.

  The image forming apparatus 100F includes a main body control unit 200E, a middle transfer drive motor control unit 300B, and a resistor RL that is a current detection unit that detects a drive current of the intermediate transfer drive motor 52.

  The main body control unit 200E includes a follow-up determination unit 470B and a speed control unit 480A. The accompanying determination unit 470B includes a current value acquisition unit 473 and a current value determination unit 474. The current detection unit 473 acquires the drive current value of the intermediate transfer drive motor 52 detected by the resistor RL. The current value determination unit 474 determines whether or not the current value acquired by the current value acquisition unit 473 is smaller than the target value.

  The target value is a current value at which it is determined that the intermediate transfer belt 51 is accompanied. The target value is determined in advance by an experimental value or the like, and may be stored in a storage device (not shown) included in the main body control unit 200E, for example.

  The speed control unit 480A is as described in the fifth embodiment.

  The operation of the image forming apparatus 100F of the present embodiment will be described below. FIG. 26 is a flowchart for explaining the operation of the main body control unit 200E in the image forming apparatus 100F of the seventh embodiment.

  When the image forming apparatus 100F receives the operation instruction, the process proceeds to step S2601, and the intermediate transfer drive motor 52 and the registration motor 96 are driven. Progressing to step S2602 following step S2601, the follow-up determination unit 470B determines whether or not the drive current value of the intermediate transfer drive motor 52 acquired by the current value acquisition unit 473 by the current value determination unit 474 is smaller than the target value. Let it be judged. Progressing to step S2603 following step S2602, if the drive current value of the intermediate transfer drive motor 52 is smaller than the target value, the accompanying determination unit 470B determines that the accompanying transfer of the intermediate transfer belt 51 has occurred.

  Since the processing of step S2603 and step S2604 is the same as the processing of step S2104 and step S2105 of FIG. 21 described in the fifth embodiment, the description thereof is omitted. The processing in the speed control unit 480A is as described in the fifth embodiment.

  As described above, according to the present embodiment, it is determined based on the drive current value of the intermediate transfer drive motor 52 whether or not the intermediate transfer belt 51 is accompanied. When it is determined that the accompanying rotation has occurred, the accompanying motor is canceled by controlling the speed of the registration motor 96.

Therefore, according to the present embodiment, when the intermediate transfer belt is rotated by the secondary transfer roller, it is possible to eliminate the rotation and perform appropriate control.
(Eighth embodiment)
The eighth embodiment of the present invention will be described below with reference to the drawings. The image forming apparatus 100G according to the present embodiment is different from the sixth embodiment in that the drive current of the intermediate transfer drive motor 52 is detected as a torque command value. Therefore, in the following description of the present embodiment, only differences from the sixth embodiment will be described, and reference numerals used in the description of the sixth embodiment will be used for those having the same functional configuration as the sixth embodiment. The same code | symbol is provided and the description is abbreviate | omitted.

  FIG. 27 is a functional configuration diagram of an image forming apparatus 100G according to the eighth embodiment.

  The image forming apparatus 100G of this embodiment includes a resistor RL that is a current detection unit that detects a drive current of the intermediate transfer drive motor 52, and an intermediate transfer drive motor control unit 300C. The intermediate transfer drive motor control unit 300C includes a drive current acquisition unit 340A. The drive current acquisition unit 340A includes a current value acquisition unit 473, a minimum determination unit 342A, and a minimum notification unit 434A.

  The current value acquisition unit 473 acquires the drive current value detected from the resistor RL. The minimum value determination unit 342A determines whether or not the detected drive current value is the minimum value. When it is determined that the drive current value is the minimum value, the minimum notification unit 434A notifies the main body control unit 200D that the drive current value is the minimum value.

  Here, the minimum value of the drive current value of the intermediate transfer drive motor 52 may be set based on, for example, an experimental value in advance.

  FIG. 28 is a flowchart for explaining the operation of the intermediate transfer drive motor controller 300C in the image forming apparatus 100G of the eighth embodiment.

  The processing from step S2801 to step S2803 in FIG. 28 is the same as the processing from step S2301 to step S2303 in FIG. 23 described in the sixth embodiment, and thus description thereof is omitted.

  In step S2804, the minimum determination unit 342A determines whether or not the drive current value of the intermediate transfer drive motor 52 acquired by the current acquisition unit 473 is the minimum value. The processing after step S2805 is the same as the processing after step S2305 in FIG.

  Further, the speed control of the registration motor 96 in the main body control unit 200D of the present embodiment is as described in the sixth embodiment.

  As described above, according to the present embodiment, it is determined whether or not the intermediate transfer belt 51 is rotated based on both the drive current value of the intermediate transfer drive motor 52 and the rotation speed. When it is determined that the accompanying rotation has occurred, the accompanying motor is canceled by controlling the speed of the registration motor 96.

  Therefore, according to the present embodiment, when the intermediate transfer belt is rotated by the registration roller, it is possible to eliminate the rotation and perform appropriate control.

  As mentioned above, although this invention has been demonstrated based on each embodiment, this invention is not limited to the requirements shown in the said embodiment. With respect to these points, the present invention can be changed within a range that does not detract from the gist of the present invention, and can be appropriately determined according to the application form.

  The present invention is applicable to an image forming apparatus, an image forming method, and a semiconductor device having a middle transfer driving motor that drives an intermediate transfer belt and a secondary transfer motor that rotates a secondary transfer roller.

1 is a diagram illustrating an overview of an entire image forming apparatus 100 according to a first embodiment. FIG. 2 is a diagram illustrating an intermediate transfer belt 51 of the image forming apparatus 100 according to the first embodiment and a peripheral configuration for driving it. 1 is a circuit block diagram of an image forming apparatus 100 according to a first embodiment. FIG. 4 is a circuit configuration diagram of an intermediate transfer drive motor control unit 300 and a secondary transfer motor control unit 400. 5 is a flowchart for explaining the operation of a middle-rotation drive motor control unit 300 of the image forming apparatus 100 according to the first embodiment. 6 is a flowchart illustrating an operation of a secondary transfer motor control unit 400 of the image forming apparatus 100 according to the first embodiment. FIG. 6 is a functional configuration diagram of an image forming apparatus 100A according to a second embodiment. 10 is a flowchart illustrating an operation of a middle-rotation drive motor control unit 300A of an image forming apparatus 100A of a second embodiment. 12 is a flowchart for explaining the operation of a secondary transfer motor control unit 400A of the image forming apparatus 100A of the second embodiment. FIG. 9 is a diagram illustrating a state in which an intermediate transfer belt 51 and a secondary transfer roller 71 are pressed against each other in an image forming apparatus 100B according to a third embodiment. FIG. 10 is a functional configuration diagram of an image forming apparatus 100B according to a third embodiment. 10 is a flowchart for explaining the operation of the image forming apparatus 100B of the third embodiment. FIG. 10 is a diagram illustrating a state in which an intermediate transfer belt 51 and a secondary transfer roller 71 are pressed against each other in an image forming apparatus 100C according to a fourth embodiment. FIG. 10 is a functional configuration diagram of an image forming apparatus 100C according to a fourth embodiment. 14 is a flowchart illustrating an operation of an image forming apparatus 100C according to a fourth embodiment. It is a 1st figure explaining the speed fluctuation of a registration roller. It is a 2nd figure explaining the speed fluctuation | variation of a registration roller. It is a figure explaining the registration roller 95 of image forming apparatus 100D of 5th embodiment. It is a functional block diagram of image forming apparatus 100D of 5th embodiment. 10 is a flowchart for explaining the operation of a intermediate transfer drive motor control unit 300 in an image forming apparatus 100D of a fifth embodiment. 14 is a flowchart illustrating an operation of a main body control unit 200C in an image forming apparatus 100D according to a fifth embodiment. It is a functional block diagram of the image forming apparatus 100E of 6th embodiment. It is a flowchart explaining operation | movement of the intermediate transfer drive motor control part 300A in the image forming apparatus 100E of 6th Embodiment. 14 is a flowchart illustrating an operation of a main body control unit 200D in an image forming apparatus 100E according to a sixth embodiment. It is a functional block diagram of the image forming apparatus 100F of 7th Embodiment. 18 is a flowchart illustrating an operation of a main body control unit 200E in an image forming apparatus 100F according to a seventh embodiment. FIG. 20 is a functional configuration diagram of an image forming apparatus 100G according to an eighth embodiment. It is a flowchart explaining operation | movement of the intermediate transfer drive motor control part 300C in the image forming apparatus 100G of 8th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 50 Intermediate transfer part 51 Intermediate transfer belt 52 Intermediate transfer drive motor 55 Scale sensor 70 Secondary transfer part 71 Secondary transfer roller 72 Secondary transfer motor 73 Repulsive roller 84 Movement motor 85 Pressure contact part 95 Registration roller 96 Registration motor 100, 100A- 100G Image forming apparatus 200, 200A to 200E Main body control unit 210, 210A Movement control unit 211, 211A Movement distance calculation unit 220 Recording paper determination unit 300, 300A, 300B, 300C Intermediate transfer drive motor control unit 340 PWM unit 340A Drive current acquisition Unit 341 PWM value calculation unit 342, 342A Minimum value determination unit 343, 343A Minimum notification unit 370, 490 Semiconductor device 400, 400A, 400B Secondary transfer motor control unit 470, 470A, 470B Revolving determination unit 471, 471A Minimum notification acquisition unit 472, 472A Speed determination unit 473 Current value acquisition unit 474 Current value determination unit 480, 480A Speed control unit 481, 481A Correction speed calculation unit 482, 482A Speed instruction output unit

Claims (13)

In an image forming apparatus, comprising: a first rotating body that drives an intermediate transfer belt; a first motor that rotates the first rotating body; and a speed detection unit that detects a rotation speed of the first rotating body. ,
A follow-up determining means for determining whether or not the intermediate transfer belt is rotated;
Control means for performing control to eliminate the accompanying,
The accompanying determination means includes
Torque command value determining means for determining whether or not the torque command value for the first motor is a preset minimum value;
Speed determining means for determining whether the rotational speed of the first rotating body detected by the speed detecting means exceeds a preset target value;
When the torque command value determining means determines that the torque command value is the minimum value and the speed determining means determines that the rotational speed of the first rotating body exceeds the target value, the intermediate transfer An image forming apparatus that determines that belt rotation has occurred. A second rotating body for conveying the recording paper;
The control means is a speed control means for controlling the rotational speed of the second rotating body so that the speed difference between the surface speed of the intermediate transfer belt and the peripheral speed of the second rotating body is within a predetermined range. The image forming apparatus according to claim 1, wherein: The speed control means is
Correction speed calculation means for calculating a correction speed for correcting the rotation speed of the second rotary body based on the rotation speed of the first rotary body detected by the speed detection means;
3. The image forming apparatus according to claim 2, wherein the rotation speed of the second rotating body is controlled based on the correction speed calculated by the correction speed calculation means. A second rotating body for transferring the toner image formed on the intermediate transfer belt to a recording paper;
The image forming apparatus according to claim 1, wherein the control unit is a movement control unit that moves the second rotating body in a direction away from the intermediate transfer belt. The movement control means includes
Distance calculating means for calculating a distance for moving the second rotating body based on the rotation speed of the first rotating body detected by the speed detecting means;
5. The image forming apparatus according to claim 4, wherein the movement of the second rotating body is controlled based on the distance calculated by the distance calculating unit. A second rotating body for transferring the toner image formed on the intermediate transfer belt to a recording paper; and a third rotating body at a position facing the second rotating body via the intermediate transfer belt; Have
The image forming apparatus according to claim 1, wherein the control unit is a movement control unit that moves the third rotating body in a direction away from the intermediate transfer belt. The movement control means includes
Based on the rotational speed of the first rotating body detected by the speed detecting means, the distance calculating means calculates a distance for moving the third rotating body,
The image forming apparatus according to claim 6, wherein the movement of the third rotating body is controlled based on the distance calculated by the distance calculating unit.   9. The image according to claim 2, wherein the second rotator is a secondary transfer roller for transferring a toner image formed on the intermediate transfer belt to the recording paper. Forming equipment.   The image forming apparatus according to claim 2, wherein the second rotating body is a registration roller that conveys the recording paper. PWM control means for controlling the first motor,
10. The image formation according to claim 1, wherein the torque command value determination unit determines whether or not a current command value supplied to the PWM control unit is a minimum value. apparatus. Current detection means for detecting a current value for driving the first motor;
The image forming apparatus according to claim 1, wherein the torque command value determination unit determines whether or not a current value supplied to the current detection unit is a minimum value. . By an image forming apparatus having a first rotating body that drives an intermediate transfer belt, a speed detecting device that detects a rotating speed of the first rotating body, and a first motor that rotates the first rotating body. In the image forming method,
A rotation determination procedure for determining whether rotation of the intermediate transfer belt has occurred;
A control procedure for performing control for eliminating the accompanying rotation of the intermediate transfer belt,
The accompanying determination procedure is as follows:
A torque command value determination procedure for determining whether or not the torque command value for the first motor is a preset minimum value;
A speed determination procedure for determining whether or not the rotational speed of the first rotating body detected by the speed detection device exceeds a preset target value;
When the torque command value determination procedure determines that the torque command value is the minimum value, and the speed determination procedure determines that the rotation speed of the first rotating body exceeds the target value, the intermediate transfer An image forming method, wherein it is determined that belt rotation has occurred. In a semiconductor device mounted on an image forming apparatus having a first rotating body that drives an intermediate transfer belt and a first motor that rotates the first rotating body,
Speed detecting means for detecting the rotational speed of the first rotating body;
A follow-up determining means for determining whether or not the intermediate transfer belt is rotated;
Control means for performing control for eliminating the accompanying rotation of the intermediate transfer belt,
The accompanying determination means includes
Torque command value determining means for determining whether or not the torque command value for the first motor is a preset minimum value;
Speed determining means for determining whether the rotational speed of the first rotating body detected by the speed detecting means exceeds a preset target value;
When the torque command value determining means determines that the torque command value is the minimum value and the speed determining means determines that the rotational speed of the first rotating body exceeds the target value, the intermediate transfer A semiconductor device, characterized in that it is determined that belt rotation has occurred.

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