JP2007199603A - Image forming apparatus, method for controlling rotation of photoreceptor, and program for allowing computer to execute this method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress irregular rotation of a photoreceptor drum 101 in an image forming apparatus. <P>SOLUTION: The image forming apparatus is provided with: a drive motor 13 for rotating the photoreceptor drum 101; a motor control part 11 for generating a motor torque command value for rotating the drive motor 13; a driver 12 for driving the drive motor 13 in both forward and backward directions by the motor torque command value; a sensor 14a and an encoder 14b for detecting the rotational speed of the photoreceptor drum 101; an acceleration detection part 15 for detecting acceleration from the detected speed; and a comparison part 16 for comparing the motor torque command value with a prescribed value: where when the comparison part 16 judges that the motor torque command value is the prescribed value or less and the acceleration is the prescribed value or more, the motor control part 11 generates a motor torque command value for reverse rotation on the basis of the acceleration to allow the drive motor to generate the rotational torque of the reverse direction. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus, a photoreceptor rotation control method, and a program for causing a computer to execute the method.

  2. Description of the Related Art Conventionally, in a tandem type color image forming apparatus, a photosensitive drum is rotationally driven by a motor, and a toner image formed on the photosensitive member is transferred to an intermediate transfer member such as a rotating belt. At the time of this transfer, the frictional resistance between the photosensitive member and the belt that suddenly fluctuates may affect the rotation of the photosensitive member and the movement of the intermediate transfer member.

  For example, when a brushless motor is used as a drive motor for the photosensitive drum, there is a problem that the rotation of the photosensitive drum cannot be accurately controlled because the belt pulls the photosensitive member by frictional force. For this reason, instead of the brushless motor, it has been considered to use a stepping motor having a holding force in the rotation of the motor. However, when a stepping motor is used, there is a problem that power consumption and noise increase and high-precision rotation control cannot be performed.

  In order to solve such a problem, in Japanese Patent Application Laid-Open No. H11-260260, torque for controlling rotation of the photosensitive drum by controlling the driving load torque in the vicinity of the operation mechanism of the cleaning blade for cleaning the photosensitive drum in the image forming apparatus. A technique is disclosed in which a limiter is arranged to control rotation by cutting off torque even when a drive motor driving a photosensitive drum runs away.

JP 2005-62233 A

  However, since the technique of Patent Document 1 is a technique for detecting torque and detecting torque when a torque equal to or greater than a predetermined value is detected, for example, it is temporarily caused by frictional resistance between the photosensitive drum and the intermediate transfer member. In this case, the torque is set to a predetermined value for uneven rotation during image formation, where the photosensitive drum is braked immediately after that and the friction is removed and the frictional resistance disappears. Even if it did not exceed, the rotational speed would rise rapidly, and could not be controlled.

  The present invention has been made in view of such a problem, and an object of the present invention is to suppress uneven rotation of the photosensitive drum accurately even if a brushless motor is used to drive a rotating system such as the photosensitive drum in the image forming apparatus. An image forming apparatus capable of controlling rotation driving, a photoreceptor rotation control method, and a program for causing a computer to execute the method.

  In order to solve the above-described problems and achieve the object, the invention according to claim 1 forms a latent image by scanning a light beam on a photoconductor based on image data, and forms an image on a recording medium. In the image forming apparatus, a drive motor that rotates each of the photosensitive members, and a motor control unit that generates a motor torque value that rotates the drive motor and drives the drive motor in both forward and reverse directions according to the generated motor torque value; Detecting means for detecting an acceleration which is a rate of change of the speed at which the photosensitive member rotates, comparing the acceleration detected by the detecting means with a predetermined value, and setting the motor torque value generated by the motor control means to a predetermined value. A comparison means for comparing, wherein the motor control means determines that the comparison means has the motor torque value equal to or less than a predetermined value and the acceleration equal to or greater than a predetermined value. And when, characterized in that allowed to apply a rotational torque in the reverse direction to the drive motor according to the motor torque value of the reverse rotation of said detecting means has generated to produce a reverse rotation of the motor torque value based on the acceleration detected.

  The invention according to claim 2 is an image forming apparatus for forming a latent image by scanning a light beam on a photosensitive member rotated by a drive motor based on image data, and forming an image on a recording medium. Motor control means for generating a motor torque value for rotationally driving the drive motor and driving the drive motor in accordance with the generated motor torque value; detection means for detecting an acceleration that is a rate of change of the rotation speed of the photoconductor; Comparing means for comparing the acceleration detected by the acceleration detecting means with a predetermined value, and comparing the motor torque value generated by the motor control means with a predetermined value; and the comparing means wherein the motor torque value is not more than a predetermined value. And, when it is determined that the acceleration is equal to or greater than a predetermined value, a braking hand that applies braking to the rotation of the photoconductor based on the acceleration detected by the detecting means. Characterized by comprising a and.

  According to a third aspect of the present invention, in the image forming apparatus according to the second aspect, the braking means applies a braking to the rotation of the photosensitive member by applying a frictional load.

  According to a fourth aspect of the present invention, in the image forming apparatus according to the second aspect, the braking unit brakes the rotation of the photosensitive member rotating in a gear connection with the drive motor by applying a frictional load. It is characterized by being added.

  According to a fifth aspect of the present invention, in the image forming apparatus according to the second aspect, the braking means includes a drum brake that brakes rotation of a rotating shaft system that rotates the photosensitive member, and the photosensitive drum is driven by the drum brake. It is characterized by applying braking to the rotation of the body.

  According to a sixth aspect of the present invention, in the image forming apparatus according to the second aspect, the braking unit includes a disk brake that brakes rotation of a rotating shaft system that rotates the photosensitive member, and the photosensitive member is driven by the disk brake. It is characterized by applying braking to the rotation of the body.

  According to a seventh aspect of the present invention, in the image forming apparatus according to the sixth aspect, the brake means is provided with a plurality of marks indicating the rotational position of the disk in the disk brake, and the detection means is the disk. The acceleration is detected by detecting a plurality of marks arranged on the screen.

  According to an eighth aspect of the present invention, in the image forming apparatus according to the second aspect, the braking unit is disposed coaxially with a rotation shaft of the driving motor and is based on an acceleration detected by the detection unit. It has a braking motor that applies braking to the rotation of the driving motor.

  According to a ninth aspect of the present invention, in the image forming apparatus according to the second aspect, the braking means is disposed coaxially with a rotation shaft of the photosensitive member gear-connected to the driving motor, and the detection means is It has a braking motor that applies braking to the rotation of the photosensitive member based on the detected acceleration.

  According to a tenth aspect of the present invention, in the image forming apparatus according to the second aspect, the braking unit is gear-connected to the driving motor, and the photosensitive member is rotated based on an acceleration detected by the detecting unit. It has a motor for braking which applies braking.

  According to an eleventh aspect of the present invention, in the image forming apparatus according to the tenth aspect, the braking means is configured such that the driving motor and the braking motor are connected to a speed increasing gear. .

  According to a twelfth aspect of the present invention, in the image forming apparatus according to the tenth aspect of the present invention, the brake means is configured such that the drive motor and the brake motor are connected to a reduction gear.

  According to a thirteenth aspect of the present invention, there is provided a photosensitive member rotation control method in an image forming apparatus that forms a latent image by scanning a photosensitive member with a light beam based on image data, and forms an image on a recording medium. A motor control step of generating a motor torque value of a drive motor for rotating the photoconductor by the motor control means and driving the drive motor in both forward and reverse directions according to the generated motor torque value, and an acceleration detection means for the photoconductor An acceleration detection step of detecting an acceleration that is a rate of change in the rotation speed of the motor, a motor torque comparison step of comparing the motor torque value generated in the motor control step with a predetermined value by a motor torque comparison unit, and an acceleration comparison unit An acceleration comparison step of comparing the acceleration detected in the acceleration detection step with a predetermined value, and the motor control step includes: When the motor torque value is less than or equal to a predetermined value in the motor torque comparison step and the acceleration is determined to be greater than or equal to a predetermined value in the acceleration comparison step, reverse rotation based on the acceleration detected in the detection step is performed. A motor torque value is generated, and a reverse rotational torque is applied to the drive motor.

  According to the fourteenth aspect of the present invention, photoconductor rotation control in an image forming apparatus that forms a latent image by causing a light beam to scan on a photoconductor rotated by a drive motor based on image data and forms an image on a recording medium. A motor torque value generating step in which the motor control means generates a motor torque value for rotationally driving the drive motor, and an acceleration that is a rate of change of the speed at which the photosensitive member rotates is detected by the acceleration detecting means. An acceleration detection step; a motor torque comparison step for comparing the motor torque value generated in the motor torque generation step with a predetermined value by the motor torque comparison unit; and an acceleration detected in the acceleration detection step by the acceleration comparison unit. The motor torque value is predetermined in the motor torque comparison step by the acceleration comparison step for comparing with a predetermined value and the braking means. If the acceleration comparison step determines that the acceleration is greater than or equal to a predetermined value, braking that applies braking to the rotation of the photoconductor based on the acceleration detected in the acceleration detection step Means.

  According to a fifteenth aspect of the present invention, in the photosensitive member rotation control method according to the fourteenth aspect, the braking step applies braking to the rotation of the photosensitive member when the braking unit applies a friction load. It is characterized by that.

  According to a sixteenth aspect of the present invention, in the photosensitive member rotation control method according to the fourteenth aspect, the braking step includes a disc brake that brakes rotation of a rotating shaft system that causes the braking unit to rotate the photosensitive member. The disk brake applies braking to the rotation of the photosensitive member.

  According to a seventeenth aspect of the present invention, in the photosensitive member rotation control method according to the sixteenth aspect, in the detection step, the detection means detects a mark indicating a plurality of rotational positions of a disk disposed in the disk brake. Thus, the acceleration is detected.

  According to an eighteenth aspect of the present invention, in the photosensitive member rotation control method according to the fourteenth aspect, in the braking step, the braking means is disposed coaxially with a rotation shaft of the driving motor, and the detection means detects the braking means. And a braking motor that applies braking to the rotation of the driving motor based on the acceleration to be applied, and applies braking to the rotation of the photosensitive member by braking by the braking motor.

  According to a nineteenth aspect of the present invention, in the photosensitive member rotation control method according to the fourteenth aspect, the braking step is based on an acceleration detected by the detecting unit when the braking unit is gear-connected to the driving motor. A braking motor for applying braking to the rotation of the photosensitive member is provided, and braking is applied to the rotation of the photosensitive member by braking by the braking motor.

  According to a twentieth aspect of the present invention, in a program, the computer causes the computer to execute the photosensitive member rotation control method according to any one of the thirteenth to nineteenth aspects.

  According to the first aspect of the present invention, the motor torque value of the drive motor for rotating the photosensitive member is generated to drive the motor, the motor torque value is equal to or less than a predetermined value, and the acceleration at which the photosensitive member rotates is increased. When it is determined that the value is equal to or greater than the predetermined value, a reverse rotation motor torque value is generated based on the detected acceleration and a reverse rotation torque is applied to the drive motor. Even if the friction is released and then suddenly accelerated to cause rotation unevenness that is difficult to control, such a state is detected and a quick and accurate control operation is performed, so that rotation unevenness of the photoreceptor is suppressed in image formation. There is an effect that can be done.

  According to the second aspect of the present invention, the motor torque value of the drive motor that drives the photosensitive member to rotate is generated to drive the motor, the motor torque value is equal to or less than the predetermined value, and the acceleration at which the photosensitive member rotates is predetermined. When it is determined that the value is equal to or greater than the value, braking is applied to the rotation of the photoconductor based on the detected acceleration, for example, resistance is generated in the rotation of the photoconductor due to friction, and then the friction is released and accelerated rapidly. Even if difficult rotation unevenness occurs, such a state is detected and a quick and accurate control operation is performed, so that it is possible to suppress the rotation unevenness of the photosensitive member in image formation.

  According to the third aspect of the present invention, it is possible to suppress uneven rotation of the photosensitive member in image formation by braking against the rotation of the photosensitive member by friction.

  According to the fourth aspect of the present invention, since the gear is connected to the drive motor and braking is performed by friction, reliable braking can be performed with a small braking force, and rotation unevenness of the photosensitive member can be suppressed in image formation. There is an effect that can be done.

  According to the fifth aspect of the present invention, since the drum brake is applied to the rotation of the photosensitive member, it is possible to suppress the rotation unevenness of the photosensitive member in image formation while preventing the scattering of the brake residue.

  According to the sixth aspect of the present invention, braking with respect to the rotation of the photosensitive member is performed by a disc brake, so that the control can be performed with a simple and lightweight configuration, and uneven rotation of the photosensitive member can be suppressed in image formation. There is an effect that can be done.

  According to the seventh aspect of the present invention, the disc brake can be used also for the encoder, the number of parts for braking and acceleration detection can be reduced, and control can be performed with a simple and lightweight configuration. There is an effect that the rotation unevenness of the photosensitive member can be suppressed in the formation.

  According to the eighth aspect of the present invention, since braking is applied by the braking motor disposed coaxially with the rotation shaft of the driving motor, the rotation unevenness of the photosensitive member is suppressed in image formation while preventing the scattering of the brake residue. There is an effect that can be done.

  According to the ninth aspect of the present invention, there is provided a braking motor which is disposed coaxially with the rotation shaft of the photosensitive member geared to the driving motor and applies braking to the rotation of the photosensitive member based on the detected acceleration. As a result, it is possible to directly apply braking to the photoconductor, so that it is possible to accurately suppress rotational nonuniformity of the photoconductor in image formation using a small-scale brake motor. .

  According to the tenth aspect of the present invention, the braking means and the driving motor are connected in gear, and the braking motor that applies the braking to the rotation of the photosensitive member based on the detected acceleration is used to brake the rotation of the photosensitive member. Thus, the degree of deceleration of the photosensitive member can be adjusted and the braking force can be arbitrarily set, so that it is possible to suppress uneven rotation of the photosensitive member in image formation.

  According to the eleventh aspect of the present invention, the braking means can increase the number of revolutions of the brake motor and set the braking force large by connecting the driving motor and the braking motor to the speed increasing gear. Can be reduced in price and size.

  According to the twelfth aspect of the present invention, the braking means can adjust the motor braking force by reducing the number of revolutions of the brake motor by connecting the driving motor and the braking motor to the reduction gear.

  According to the thirteenth aspect of the present invention, the motor torque value of the drive motor that drives the photosensitive member to rotate is generated to drive the motor, the motor torque value is equal to or less than a predetermined value, and the acceleration at which the photosensitive member rotates is increased. When it is determined that the value is equal to or greater than the predetermined value, a reverse rotation motor torque value is generated based on the detected acceleration and a reverse rotation torque is applied to the drive motor. Even if the friction is released and then suddenly accelerated to cause rotation unevenness that is difficult to control, such a state is detected and a quick and accurate control operation is performed, so that rotation unevenness of the photoreceptor is suppressed in image formation. There is an effect that can be done.

  According to the fourteenth aspect of the present invention, the motor torque value of the drive motor that drives the photosensitive member to rotate is generated to drive the motor, the motor torque value is equal to or less than a predetermined value, and the acceleration at which the photosensitive member rotates is predetermined. When it is determined that the value is equal to or greater than the value, braking is applied to the rotation of the photoconductor based on the detected acceleration, for example, resistance is generated in the rotation of the photoconductor due to friction, and then the friction is released and accelerated rapidly. Even if difficult rotation unevenness occurs, such a state is detected and a quick and accurate control operation is performed, so that it is possible to suppress the rotation unevenness of the photosensitive member in image formation.

  According to the fifteenth aspect of the present invention, it is possible to suppress uneven rotation of the photosensitive member in image formation by braking against the rotation of the photosensitive member by friction.

  According to the sixteenth aspect of the present invention, braking with respect to the rotation of the photosensitive member is performed by a disc brake, so that it is possible to control with a simple and lightweight configuration, and it is possible to suppress rotation unevenness of the photosensitive member in image formation. There is an effect that can be done.

  According to the seventeenth aspect of the present invention, the disc brake can also be used as an encoder, the number of parts for braking and acceleration detection can be reduced, and control can be performed with a simple and lightweight configuration. There is an effect that the rotation unevenness of the photosensitive member can be suppressed in the formation.

  According to the eighteenth aspect of the present invention, since braking is applied by the braking motor disposed coaxially with the rotation shaft of the driving motor, the rotation unevenness of the photosensitive member is suppressed in image formation while preventing scattering of the brake residue. There is an effect that can be done.

  According to the nineteenth aspect of the present invention, the braking means and the driving motor are connected in gear, and the braking motor for braking the rotation of the photosensitive member based on the detected acceleration is provided. In addition, since the degree of deceleration of the photoconductor can be adjusted and the braking force can be arbitrarily set, there is an effect that uneven rotation of the photoconductor can be suppressed in image formation.

  According to the twentieth aspect of the invention, there is an effect that the computer can execute the photosensitive member rotation control method according to any one of the thirteenth to nineteenth aspects.

  Exemplary embodiments of an image forming apparatus, a photosensitive member rotation control method, and a program for causing a computer to execute the method according to the present invention will be described below with reference to the accompanying drawings. It explains in detail along with.

(1. Embodiment 1)
The image forming apparatus according to the first embodiment scans a photosensitive member with a light beam based on image data to form a latent image, and forms an image on a recording medium. Detected when the command value of the motor torque that rotates in both directions is generated to control the drive motor, and the motor torque value is lower than the predetermined value and the acceleration that is the rate of change of the rotational speed of the photosensitive member is greater than or equal to the predetermined value A low-rotation or reverse-rotation torque command value is generated based on the acceleration to reduce the rotational speed of the drive motor.

  With this configuration, during the image forming operation, for example, after the photoreceptor receives a resistance such as a frictional resistance from the transfer body, it is released from the resistance and accelerated instantaneously. In this case, the rotation of the photosensitive member can be accurately controlled by applying a torque in the reverse direction to the drive motor.

  FIG. 1 is a functional block diagram of the image processing apparatus according to the first embodiment. FIG. 2 is a diagram for explaining that the motor controller controls the drive motor. The image forming apparatus includes a scanner 1, an input processing unit 2, an output processing unit 3, a motor controller 10, a drive motor 13, a sensor 14a, an encoder 14b, an image forming unit 100, and a photosensitive drum 101.

  The scanner 1 reads a document image. The scanner 1 irradiates an original moving in the sub-scanning direction with reading light, and photoelectrically converts the reflected light by a photoelectric conversion element such as a CCD (Charge Coupled Device) to read an image of the original. When the scanner 1 includes an ADF (Auto Document Feeder) that sends out a plurality of documents to be mounted one by one, the documents sent from the ADF are sequentially read as analog image data and transmitted to the input processing unit 2. To do.

  The input processing unit 2 receives the analog data read by the scanner 1, converts it into digital image data, and transmits it to the output processing unit 3.

  The output processing unit 3 performs output processing on the input image data based on the processing settings received by the image forming apparatus. The output processing unit 3 performs various necessary image processing such as gamma conversion on the image data.

  The image forming unit 100 forms an image according to the setting of the output processing performed by the output processing unit 3. The image forming operation by the image forming unit 100 is not a main part of the present invention and will be described later.

  The drive motor 13 and the photosensitive drum 101 are often included in the image forming unit 100 in mounting, but are described here as being disposed outside the image forming unit 100 for explanation. The drive motor 13 drives the photosensitive drum 101. The present invention relates to rotation control of a photosensitive drum 101 driven by a drive motor 13.

  The motor controller 10 included in the image forming apparatus according to the first embodiment includes a motor control unit 11, a driver 12, an acceleration detection unit 15, and a comparison unit 16.

  The sensor 14a detects the rotation of the photoconductor 101, and the encoder 14b detects the rotation speed of the photoconductor drum 101 from the detected rotation. The acceleration detection unit 15 detects acceleration by calculating a temporal difference from the speed detected by the encoder 14b.

  The motor control unit 11 calculates the rotational speed of the drive motor 13 based on the output from the encoder 14b, and generates a torque command value for the motor so as to be the set speed. Further, the motor control unit 11 converts the torque command value into a PWM (Pulse Width Modulation) output and outputs a motor phase current pattern to the driver 12. Further, when receiving a brake signal, the motor control unit 11 outputs a phase current pattern in the short brake mode.

  The comparison unit 16 compares the torque command value and the acceleration detected by the acceleration detection unit 15 with a predetermined value, respectively, and determines a case where the torque command value remains low and the speed is increasing.

  The case where the torque command value is small and the speed is increasing is, for example, a state where the friction from the transfer belt with respect to the photosensitive member 101 is generated and decelerated, and then the friction is released and the movement starts abruptly. In this case, the rotation is in a state of uneven rotation, which is difficult to control with the conventional technology. In this way, the comparison unit 16 detects that the control has fallen into an uncontrollable state with the prior art. The comparison unit 16 transmits a brake signal for decelerating the drive of the motor to the motor control unit 11.

  The motor control unit 11 receives the brake signal, converts it into a PWM output as described above, transmits it to the driver 12, and controls the drive motor 13 to reduce the speed. Here, the driver 12 is configured to include an H-bridge circuit for the drive motor 13.

  FIG. 3 is a diagram illustrating timing waveforms of a torque command value, a motor encoder waveform, a measurement clock, and a brake signal. In the figure, the right direction is the direction of time passage. The torque command value continues to be below the set value within the range of reference numeral 212. The encoder waveform is narrow in the range of reference numeral 222. This indicates that the time for detection is shortened, and the speed is increased accordingly. The comparator 16 determines such a state, and the comparator 16 generates a brake signal 242.

  FIG. 4 is a diagram for explaining an H-bridge circuit. Here, the H bridge circuit 310 and the control logic 320 are included in the driver 12. The H bridge circuit is a drive driver capable of flowing a current bidirectionally with respect to the motor coil, and can rotate the motor forward and backward.

  During forward rotation, Tr1 and Tr4 in the figure are ON, and Tr2 and Tr3 are OFF (Tr stands for transistor). Current flows in the direction indicated by the thick solid line. Further, during reverse rotation, Tr1 and Tr4 are OFF and Tr2 and Tr3 are ON. Current flows in the direction indicated by the thick broken line.

  In addition, a short brake can be used, and Tr1 and Tr2 are turned ON and Tr3 and Tr4 are turned OFF during motor rotation. Or, conversely, Tr1 and Tr2 may be OFF and Tr3 and Tr4 may be ON. In this case, a current loop is created, and the energy stored in the motor coil is used to act as a brake that generates reverse torque.

  FIG. 5 is a flowchart illustrating control of the photosensitive drum in the image forming apparatus according to the first embodiment. The motor control unit 11 generates a torque command value for the drive motor 13 that rotates the photosensitive drum 101 based on the setting value initially set in the image forming apparatus, and transmits the torque command value to the driver 12 (step S101).

  The motor control unit 11 converts the generated torque command value into a PWM output, outputs a phase current pattern to the driver 12, and controls the drive motor. Here, the driver 12 is configured to include an H-bridge circuit as shown in FIG. 4 (step S102).

  The acceleration detector 15 detects the rotational acceleration of the photosensitive drum 101 from the rotational speed of the photosensitive drum 101 detected by the sensor 14a and the encoder 14b. And the comparison part 16 determines whether a torque instruction value is below a predetermined value (step S103). Here, when the comparison unit 16 determines that the torque command value is not equal to or less than the predetermined value (No in Step S103), the process returns to Step S101 and shifts to normal drive motor control by the motor control unit 11 (Step S102). ).

  On the other hand, when the comparison unit 16 determines that the torque command value is equal to or less than the predetermined value (Yes in step S103), the comparison unit 16 further determines whether the acceleration is equal to or higher than the predetermined value (step S104). ). If it is determined that the value is not equal to or greater than the predetermined value (No in step S104), the process returns to step S101, and the control of the drive motor by the motor control unit 11 is performed.

  On the other hand, when the comparison unit 16 determines that the acceleration is equal to or greater than the predetermined value, the comparison unit 16 generates a brake signal and transmits the brake signal to the motor control unit 11 (step S105).

  The motor control unit 11 converts the brake signal into a PWM output and transmits it to the driver 12 (step S106), and the driver reduces the rotation of the motor with respect to the drive motor 13 (step S107).

  FIG. 6 is a diagram for explaining an image forming operation of the image forming apparatus according to the first embodiment. Here, an image forming operation of the image forming unit 100 in the image forming apparatus will be described. This image forming apparatus is referred to as photoreceptors 101Y, 101C, 101M, and 101B (if not specified, simply referred to as photoreceptor 101), and developing apparatuses 102Y, 102C, 102M, and 102B (if not specified, simply referred to as developing apparatus 102). ), Transfer devices 103Y, 103C, 103M, and 103B (hereinafter simply referred to as transfer device 103 if not specified), and a tandem type electrophotographic apparatus (color copying machine or color printer) including an intermediate transfer belt 105.

  The photosensitive member 101 is provided with a developing device 102 and a transfer device 103, respectively. A single color toner image is formed on the photosensitive member 101, and the formed single color toner image is transferred to the intermediate transfer belt 105. They are contacted and sequentially transferred onto the intermediate transfer belt 105 to form a composite color image, and the formed image is collectively transferred to a sheet-like transfer paper. A full color image is formed by this transfer operation.

  Further, the image forming apparatus is provided with a charging device 106, a cleaning device 107, and a charge eliminating device 108 around the photosensitive member 101, and each color is supplied to the photosensitive member 101 from the laser writing unit 109 based on an image signal. A laser beam corresponding to the image is scanned to form an electrostatic latent image.

  FIG. 7 is a diagram for explaining the image forming operation of the direct transfer type image forming apparatus. This image forming apparatus includes a direct transfer type image forming system that directly transfers an image on a photoconductor to a recording sheet, and portions corresponding to those in FIG.

  The image forming apparatus shown in FIG. 7 has a plurality of photoconductors 101 </ b> Y, 101 </ b> C, 101 </ b> M, and 101 </ b> B, each of which is a plurality of image carriers that are formed with different colors and can be rotated independently. Each transfer device 103 is configured to transfer each image on the photoconductor 101 directly onto a transfer paper P, which is a recording paper, at a transfer position where each image formed on the photoconductor 101 corresponds to each of the plurality of photoconductors 101. . The transfer conveyance belt 230 is stretched between a driving roller 232 and a driven roller 233 that are rotated by a conveyance driving motor 231 and rotates in the direction indicated by an arrow.

  FIG. 8 is a diagram illustrating an image forming operation of an image forming apparatus including two intermediate transfer members. The image forming apparatus shown in FIG. 8 is a tandem type image forming apparatus including first and second intermediate transfer members.

  The image forming apparatus includes four photoconductors 101Y, 101C, 101M, and 101B, which are four image carriers that can be independently rotated on which images of different colors of yellow, cyan, magenta, and black are formed. Of the four photoreceptors, the images formed on the two photoreceptors 101Y and 101C are the primary transfer positions P5 and P6, respectively, and the images formed on the remaining two photoreceptors 101M and 101B are 1 respectively. There are provided first intermediate transfer members 334A and 334B that can be independently rotated at the two transfer positions P7 and P8, respectively. First intermediate transfer members 334A and 334B are driven to rotate by first intermediate transfer motors 335A and 335B, respectively.

  Further, in the image forming apparatus shown in FIG. 8, each of the images transferred to the two first intermediate transfer members 334A and 334B is transferred in a superimposed state at the secondary transfer positions P9 and P10. A transfer body (drum) 336 is provided, and the second intermediate transfer drum 336 is rotated by a second intermediate transfer motor 337. Further, a transfer device (transfer roller) 338 serving as a transfer unit for transferring the image transferred to the second intermediate transfer drum 336 to the transfer paper P at the tertiary transfer position P11 and the transfer paper P shown in FIG. A conveyor belt 339 that rotates in the direction of the arrow is also provided. The conveyor belt 339 is stretched between the driving roller 340 and the driven roller 341, and is rotated in the direction indicated by the arrow in FIG. 8 when the driving roller 340 is rotated by the driving motor 342.

  The detailed operation of image formation in these color image forming apparatuses is the same as that of a known image forming apparatus, and is not directly related to the present invention, and thus will be omitted.

  As described above, the image processing apparatus according to the first embodiment scans the light beams on the plurality of photoconductors 101 based on the image data input from the scanner 1 to form latent images, and images of a plurality of colors on the recording medium. In the image forming apparatus for forming the image forming apparatus, a drive motor 13 for rotating the photosensitive member 101, a motor control unit 11 for generating a torque command value for rotating the drive motor 13, and a forward / reverse direction of the drive motor 13 based on the torque command value. , A driver 12 that drives the sensor 101, a sensor 14 a and an encoder 14 b that detect the rotation speed of each photoconductor 101, an acceleration detection unit 15 that detects an acceleration that is a rate of change from the detected speed, and an acceleration detection unit 15 A comparison unit 16 that compares the measured acceleration with a predetermined value and compares the motor torque value generated by the motor control unit 11 with a predetermined value. When the comparison unit 16 determines that the motor torque command value is less than or equal to the predetermined value and the acceleration is greater than or equal to the predetermined value, the motor control unit 11 generates a brake signal based on the detected acceleration, and the driver 12 The rotational speed of 13 is reduced.

  With this configuration, during the image forming operation, for example, after the photoreceptor receives a resistance such as a frictional resistance from the transfer body, it is suddenly released from the resistance and the photoreceptor drum 101 is accelerated instantaneously. Even if the rotation unevenness of the drum 101 occurs and the rotation control becomes difficult, a torque for reducing the rotation speed can be generated to accurately control the rotation of the photosensitive member.

(2. Embodiment 2)
FIG. 9 is a functional block diagram of the image forming apparatus according to the second embodiment. FIG. 10 is a diagram for explaining that the motor controller controls the brake device disposed coaxially with the photosensitive member.

  The image forming apparatus according to the second embodiment is different from the first embodiment in that the image forming apparatus further includes a brake device 24 that applies braking to the rotation of the photosensitive member, and a brake braking unit 22. When the comparison unit 16 determines that the motor torque command value is equal to or lower than the predetermined value and the acceleration is equal to or higher than the predetermined value, the brake control unit 22 applies the brake device 24 to the brake device 24 based on the acceleration detected by the acceleration detection unit 15. On the other hand, the rotation of the photosensitive member 101 is braked.

  With this configuration, during the image forming operation, for example, after the photosensitive member 101 receives a resistance such as a frictional resistance from the transfer body, it is released from the resistance and accelerated instantaneously. In this case, the rotation of the photosensitive member 101 can be controlled by applying a brake by the control of the brake device 24. Hereinafter, differences from the image processing apparatus according to the first embodiment will be mainly described.

  The comparison unit 16 compares the torque command value with the acceleration detected by the acceleration detection unit 15, and detects a state in which the torque command value is not more than a predetermined value and at the same time the acceleration is not less than the predetermined value.

  The brake control unit 22 transmits a brake signal to the brake device 24 when it is determined that the torque command value is equal to or smaller than the predetermined value and the acceleration is equal to or larger than the predetermined value.

  Here, the brake device 24 is connected to the motor rotation shaft and applies a brake by turning on and off the brake operation as necessary, and releases the brake. About the timing of braking, it is the same as that of the case of Embodiment 1 which performed the brake operation by controlling the drive motor 13 (FIG. 3).

  Here, the photosensitive drum 101 and the brake device 24 may be coaxial, and a driving motor may be connected to the shaft by a gear. As a result, a braking operation can be applied by directly controlling the rotation axis of the photosensitive drum 101.

  FIG. 11 is a diagram for explaining various brakes and their operations. The drum brake 1010 can be applied to the brake device 24 of the image forming apparatus. The drum brake 1010 generates a brake effect by connecting the brake drum 1011 coaxially with the motor 101 and transmitting the drive, and spreading the brake shoe 1012. As an advantage of applying the drum brake 1010, the brake residue is hardly scattered.

  Also, the disc brake 1020 can be applied to the brake device 24. The disc 1021 is driven by being connected coaxially with the motor 101, and a brake effect is produced by sandwiching the disc 1021 with a brake pad 1022. As an advantage of applying the disc brake 1020, since the structure is simple, the cost can be suppressed. Here, in mounting, it is preferable to have a sealed structure so that the brake debris in the disc brake device does not scatter.

  Also, the disc brake 1030 is provided with slits 1033 along the circumference in the vicinity of the outer periphery of the disc 1031 surface, and the slits 1033 are configured to be detected by the sensor 14a, so that the encoder and the disc 1031 are configured in the same part. . With this configuration, the rotation speed of the photosensitive drum 101 is detected by detecting the rotation speed of the disk 1031.

  FIG. 12 is a flowchart for explaining the photoconductor rotation control procedure according to the second embodiment. Since steps S201 to S204 are the same as the procedure according to the first embodiment, the description thereof is omitted.

  When the comparison unit 16 determines that the torque command value is equal to or less than the predetermined value (Yes in step S203) and the acceleration is equal to or greater than the predetermined value (Yes in step S204), the brake control unit 22 determines based on the detected acceleration. The brake signal is transmitted to the brake device 24 (step S205). In accordance with the received brake signal, the brake device 24 turns on and off the brake operation to apply braking to the rotation of the photoconductor (step S206).

  Thus, in the image forming apparatus according to the second embodiment, during the image forming operation, for example, after the photosensitive member 101 receives a resistance such as a frictional resistance from the transfer body, it is released from the resistance and accelerated instantaneously. If it becomes difficult to control the rotation of the photoconductor, the brake device 24 that uses frictional force is controlled on the photoconductor 101 to apply the brake to control the rotation of the photoconductor 101. It is possible to control a rotating body.

(Modification)
FIG. 13 is a schematic diagram illustrating a configuration of an image forming apparatus according to a modification. Here, in the image forming apparatus, the photosensitive member 101 and the brake device 24 'rotate coaxially, and the drive motor 13 is connected to the shaft via a gear and is driven to rotate. That is, the brake device 24 ′ directly applies braking to the photoreceptor 101.

(Modification)
FIG. 14 is a schematic diagram illustrating a configuration of an image forming apparatus according to a modification. Here, in the image forming apparatus, the photosensitive member 101 and the drive motor 13 rotate on the same axis, and the brake device 24 ″ is connected to the shaft via a gear to control the rotation of the drive motor 13. That is, the brake device. 24 ″ controls the rotation of the photosensitive member indirectly through a gear.

(3. Embodiment 3)
FIG. 15 is a functional block diagram of the image processing apparatus according to the third embodiment. The image processing apparatus according to the third embodiment is different from the first embodiment in that a brake motor 33 that applies braking to the drive motor 13 is further provided, and the brake control unit 34 controls the brake motor 33. That is, braking is applied to the drive motor using the brake motor 33 instead of the brake device using mechanical friction as in the second embodiment. Hereinafter, differences from the image processing apparatus according to the second embodiment will be mainly described.

  When the comparison unit 16 determines that the torque command value is equal to or less than the predetermined value and the acceleration at which the drum 101 rotates is equal to or greater than the predetermined value, the brake control unit 34 transmits a brake signal to the driver 32 and the brake motor 33. Apply a short brake. Here, the driver 32 is configured to include an H bridge circuit of the drive motor 13 and an H bridge circuit of the brake motor 33.

  The brake motor 33 is connected to the motor shaft and rotates in the same manner when the motor is driven. When the driver 32 receives the brake ON signal, the driver 32 transmits the braking force of the brake motor 33 to the drive motor 13 by a short brake using regenerative power.

  FIG. 16 is a diagram for explaining an H-bridge circuit of the brake motor 33. The brake motor 33 applies a braking operation to the drive motor 13 by a short brake according to a signal command. The brake motor 33 exerts a braking operation on the drive motor 13 by applying reverse rotation torque in accordance with the signal command. In the figure, a short brake is applied by a route passing through a power source indicated by a thick line, and a short brake is applied by a route passing through a ground indicated by a thick broken line.

  FIG. 17 is a flowchart for explaining the photoconductor rotation control procedure according to the third embodiment. Since steps S301 to S304 are the same as the procedure according to the first embodiment, the description thereof is omitted.

  When the comparison unit 16 determines that the torque command value is equal to or less than the predetermined value (Yes in step S303) and the acceleration is equal to or greater than the predetermined value (Yes in step S304), the brake control unit 34 determines based on the detected acceleration. The short brake signal is transmitted to the driver 32 (step S305). In accordance with the received brake signal, the driver 32 applies braking to the drive motor 13 by a short brake by the regenerative electric power of the brake motor 33 (step S306).

  Thus, in the image forming apparatus according to the third embodiment, during the image forming operation, for example, after the photoreceptor 101 receives a resistance such as a frictional resistance from the transfer body, it is released from the resistance and accelerated instantaneously. When the rotation drive control of the photoconductor 101 becomes difficult, the rotation drive control is performed by applying a short brake to the drive motor by the regenerative electric power of the brake motor 33 with respect to the photoconductor 101. Therefore, accurate rotation control of the photoconductor is performed. It can be performed.

  FIG. 18 is a schematic diagram illustrating a configuration of an image forming apparatus according to the third embodiment. Here, in the image forming apparatus, the photoconductor 101, the brake motor 33a, and the drive motor 13 are coaxial. With this configuration, the brake motor 33 a can directly apply a braking operation to the drive motor 13.

(Modification)
FIG. 19 is a schematic diagram illustrating a configuration of an image forming apparatus according to a modification. Here, the photosensitive member 101 and the brake motor 33b rotate on the same axis, and the drive motor 13 is connected to the shaft via a gear and driven. That is, the brake motor 33b directly applies braking to the photosensitive member 101.

(Modification)
FIG. 20 is a schematic diagram illustrating a configuration of an image forming apparatus according to a modification. Here, the photosensitive member 101 and the drive motor 13 rotate on the same axis, and the brake motor 33c is connected to the shaft via a gear to control the drive motor 13. That is, the brake motor 33c indirectly controls the rotation of the photosensitive member 101 via the gear.

(Modification)
FIG. 21 is a diagram illustrating a gear ratio of a gear connecting the brake motor and the drive motor. FIG. 22 is another diagram illustrating a gear ratio for connecting the brake motor and the drive motor.

  The gear shown in FIG. 21 is a speed increasing gear with respect to the drive motor 13, and makes the brake force by the brake motor 33c1 gentle. The gear shown in FIG. 22 is a reduction gear for the drive motor 13, and is designed to increase the braking force by the brake motor 33c2. Thus, when connecting the brake motor 33 and the drive motor 13 with a gear, the strength of the brake operation can be set by setting the gear ratio.

(4. Hardware configuration etc.)
FIG. 23 is a block diagram illustrating a hardware configuration of the image forming apparatus according to the embodiment. This image forming apparatus is configured as a multifunction peripheral (MFP) having multiple functions such as a fax machine and a scanner. As shown in the figure, this MFP has a configuration in which a controller 2210 and an engine unit 2260 are connected via a PCI (Peripheral Component Interconnect) bus. A controller 2210 is a controller that controls inputs from the FCUI / F 2230 and the operation display unit 2220 such as control of the entire MFP, image processing control, rotation drive control, and various controls. The engine unit 2260 is an image processing engine that can be connected to a PCI bus, and includes, for example, an image processing portion such as error diffusion and gamma conversion for acquired image data.

  The controller 2210 includes a CPU 2211, a north bridge (NB) 2213, a system memory (MEM-P) 2212, a south bridge (SB) 2214, a local memory (MEM-C) 2217, and an ASIC (Application Specific Integrated Circuit). 2216 and the hard disk drive 5, and the north bridge 2213 and the ASIC 2216 are connected by an AGP (Accelerated Graphics Port) bus 2215. The MEM-P 2212 further includes a ROM (Read Only Memory) 2212a and a RAM (Random Access Memory) 2212b.

  The CPU 2211 performs overall control of the MFP, has a chip set including the NB 2213, the MEM-P 2212, and the SB 2214, and is connected to other devices via the chip set.

  The NB 2213 is a bridge for connecting the CPU 2211 to the MEM-P 2212, SB 2214, and AGP 2215, and includes a memory controller that controls reading and writing to the MEM-P 2212, a PCI master, and an AGP target.

  The MEM-P 2212 is a system memory used as a memory for storing programs and data, a memory for developing programs and data, and the like, and includes a ROM 2212a and a RAM 2212b. The ROM 2212a is a read-only memory used as a program / data storage memory, and the RAM 2212b is a writable / readable memory used as a program / data development memory, an image drawing memory during image processing, and the like.

  The SB 2214 is a bridge for connecting the NB 2213 to a PCI device and peripheral devices. The SB 2214 is connected to the NB 2213 via a PCI bus, and an FCUI / F 2230 and the like are also connected to the PCI bus.

  The ASIC 2216 is an IC (Integrated Circuit) for multimedia information processing having hardware elements for multimedia information processing, and has a role of a bridge for connecting the AGP 2215, the PCI bus, the HDD 2218, and the MEM-C 2217, respectively.

  The ASIC 2216 includes a PCI target and an AGP master, an arbiter (ARB) that forms the core of the ASIC 2216, a memory controller that controls the MEM-C 2217, and a plurality of DMACs (Direct Memory) that perform rotation of image data using hardware logic or the like. A Universal Serial Bus (USB) 2240 and IEEE (The Institute of Electrical and Engineering Engineers) 1394 interface 2250 are connected between the Access Controller and the engine unit 2260 via a PCI bus.

  The MEM-C 2217 is a local memory used as a transmission image buffer and a code buffer, and the HDD 2218 is a storage for storing image data, programs, font data, and forms.

  The AGP 2215 is a bus interface for a graphics accelerator card that has been proposed for speeding up graphics processing, and speeds up the graphics accelerator card by directly accessing the MEM-P 2212 with high throughput.

  The operation display unit 2220 connected to the ASIC 2216 receives an operation input from the operator and transmits the operation input information received by the ASIC 2216.

  A photoreceptor rotation control program executed by the MFP according to the embodiment is provided by being incorporated in advance in a ROM or the like.

  The photosensitive member rotation control program executed by the image forming apparatus according to the embodiment is a file in an installable format or an executable format, and is a CD-ROM, a flexible disk (FD), a CD-R, a DVD (Digital Versatile Disk). For example, the program may be recorded on a computer-readable recording medium.

  Furthermore, the photoconductor rotation control program executed by the MFP according to the embodiment may be stored on a computer connected to a network such as the Internet and provided by being downloaded via the network. Further, the photoconductor rotation control program executed by the MFP according to the embodiment may be provided or distributed via a network such as the Internet.

  The photosensitive member rotation control program executed by the MFP according to the embodiment has a module configuration including the above-described units (the motor control unit 11, the driver 12, the acceleration detection unit 15, the comparison unit 16, and the like). As hardware, a CPU (processor) reads out and executes a photosensitive member rotation control program from the ROM, so that the above-described units are on the main storage device, the motor control unit 11, the driver 12, the acceleration detection unit 15, and the comparison unit 16. Etc. are generated on the main memory.

  The embodiment or modification of the present invention described above is an example for description, and the present invention is not limited to these specific examples described here.

  As described above, the image forming apparatus, the photosensitive member rotation control method, and the program for causing the computer to execute the method according to the present invention are useful for the image forming technology, and particularly for the intermediate transfer method and the collective belt transfer method. It is suitable for a drive motor control technique in applied tandem color image formation.

1 is a functional block diagram of an image processing apparatus according to Embodiment 1. FIG. It is a figure explaining that a motor controller controls a drive motor. It is a figure which shows the timing waveform of a torque command value, a motor encoder waveform, a measurement clock, and a brake signal. It is a figure explaining an H bridge circuit. 3 is a flowchart illustrating control of a photosensitive drum in the image forming apparatus according to the first embodiment. 6 is a diagram illustrating an image forming operation of the image forming apparatus according to the first embodiment. FIG. FIG. 6 is a diagram illustrating an image forming operation of a direct transfer type image forming apparatus. FIG. 6 is a diagram for explaining an image forming operation of an image forming apparatus including two intermediate transfer members. 6 is a functional block diagram of an image forming apparatus according to Embodiment 2. FIG. It is a figure explaining that a motor controller controls the brake device arrange | positioned coaxially with a photoconductor. It is a figure explaining various brakes and the operation | movement of them. 6 is a flowchart for explaining a photoreceptor rotation control procedure according to the second embodiment. It is a schematic diagram which shows the structure of the image forming apparatus by a modification. It is a schematic diagram which shows the structure of the image forming apparatus by a modification. 6 is a functional block diagram of an image processing apparatus according to Embodiment 3. FIG. It is a figure explaining the H bridge circuit of the brake motor. 10 is a flowchart for explaining a photoreceptor rotation control procedure according to the third embodiment. 6 is a schematic diagram illustrating a configuration of an image forming apparatus according to Embodiment 3. FIG. It is a schematic diagram which shows the structure of the image forming apparatus by a modification. It is a schematic diagram which shows the structure of the image forming apparatus by a modification. It is a figure explaining the gear ratio of the gear which connects a brake motor and a drive motor. It is another figure explaining the gear ratio which connects a brake motor and a drive motor. 1 is a block diagram illustrating a hardware configuration of an image forming apparatus according to an embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Scanner 2 Input processing part 3 Output processing part 10 Motor controller 13 Drive motor 14a Sensor 14b Encoder 100 Image forming part 101 Photosensitive drum

Claims (20)

In an image forming apparatus that forms a latent image by scanning a light beam on a photoconductor based on image data, and forms an image on a recording medium.
Drive motors for rotating the photoreceptors,
Motor control means for generating a motor torque value for rotationally driving the drive motor and driving the drive motor in both forward and reverse directions according to the generated motor torque value;
Detecting means for detecting an acceleration which is a rate of change of a rotating speed of the photosensitive member;
Comparing means for comparing the acceleration detected by the detecting means with a predetermined value, and comparing the motor torque value generated by the motor control means with a predetermined value;
With
When the comparison means determines that the motor torque value is less than a predetermined value and the acceleration is more than a predetermined value, the motor control means reversely rotates the motor torque based on the acceleration detected by the detection means. A reverse rotation torque is applied to the drive motor in accordance with the reverse rotation motor torque value generated and generated. In an image forming apparatus that forms a latent image by scanning a light beam on a photosensitive member rotated by a drive motor based on image data, and forms an image on a recording medium.
Motor control means for generating a motor torque value for rotating the drive motor and driving the drive motor according to the generated motor torque value;
Detecting means for detecting an acceleration which is a rate of change of a rotating speed of the photosensitive member;
Comparing means for comparing the acceleration detected by the acceleration detecting means with a predetermined value, and comparing the motor torque value generated by the motor control means with a predetermined value;
When the comparison means determines that the motor torque value is less than or equal to a predetermined value and the acceleration is greater than or equal to a predetermined value, the braking means applies braking to the rotation of the photoconductor based on the acceleration detected by the detection means Means,
An image forming apparatus comprising:   The image forming apparatus according to claim 2, wherein the braking unit applies braking to the rotation of the photosensitive member by applying a friction load.   The image forming apparatus according to claim 2, wherein the braking unit applies a friction load to apply braking to the rotation of the photosensitive member that rotates in a gear connection with the drive motor.   3. The brake device according to claim 2, wherein the braking means includes a drum brake that brakes rotation of a rotating shaft system that rotates the photosensitive member, and applies braking to the rotation of the photosensitive member by the drum brake. The image forming apparatus described.   3. The brake unit according to claim 2, further comprising a disc brake that brakes rotation of a rotating shaft system that rotates the photosensitive member, and applies braking to the rotation of the photosensitive member by the disc brake. The image forming apparatus described. The braking means is provided with a plurality of marks indicating the rotational position of the disk in the disk brake,
The image forming apparatus according to claim 6, wherein the detection unit detects the acceleration by detecting a plurality of marks arranged on the disc.   The braking means includes a braking motor which is disposed coaxially with the rotation shaft of the driving motor and applies braking to the rotation of the driving motor based on the acceleration detected by the detection means. The image forming apparatus according to claim 2.   The braking means is disposed coaxially with the rotation shaft of the photosensitive member geared to the driving motor, and applies braking to the rotation of the photosensitive member based on the acceleration detected by the detecting means. The image forming apparatus according to claim 2, further comprising:   3. The braking means includes a braking motor that is gear-connected to the driving motor and applies braking to the rotation of the photoconductor based on acceleration detected by the detecting means. The image forming apparatus described in 1.   The image forming apparatus according to claim 10, wherein the braking unit is configured such that the driving motor and the braking motor are connected to a speed increasing gear.   The image forming apparatus according to claim 10, wherein the braking unit includes a reduction gear connected to the driving motor and the braking motor. A photosensitive member rotation control method in an image forming apparatus for forming a latent image by causing a light beam to scan on a photosensitive member based on image data, and forming an image on a recording medium,
A motor control step of generating a motor torque value of a drive motor that rotationally drives the photosensitive member by a motor control means and driving the drive motor in both forward and reverse directions according to the generated motor torque value;
An acceleration detecting step of detecting an acceleration which is a rate of change of a speed at which the photosensitive member rotates by an acceleration detecting unit;
A motor torque comparing step of comparing a motor torque value generated in the motor control step with a predetermined value by a motor torque comparing means;
An acceleration comparison step of comparing the acceleration detected in the acceleration detection step with a predetermined value by an acceleration comparison means,
In the motor control step, the acceleration detected in the detection step when the motor torque comparison step determines that the motor torque value is equal to or less than a predetermined value and the acceleration comparison step determines that the acceleration is equal to or greater than a predetermined value. And generating a reverse rotation motor torque value to apply a reverse rotation torque to the drive motor. A photosensitive member rotation control method in an image forming apparatus for forming a latent image by causing a light beam to scan on a photosensitive member rotated by a drive motor based on image data, and forming an image on a recording medium,
A motor torque value generating step in which a motor control means generates a motor torque value for rotationally driving the drive motor;
An acceleration detecting step of detecting an acceleration which is a rate of change of a speed at which the photosensitive member rotates by an acceleration detecting unit;
A motor torque comparing step of comparing the motor torque value generated in the motor torque generating step with a predetermined value by the motor torque comparing means;
An acceleration comparison step of comparing the acceleration detected in the acceleration detection step with a predetermined value by an acceleration comparison means;
When the braking means determines that the motor torque value is less than or equal to a predetermined value in the motor torque comparison step, and the acceleration comparison step determines that the acceleration is greater than or equal to a predetermined value, it is detected in the acceleration detection step Braking means for applying braking to the rotation of the photoconductor based on the acceleration to be performed;
A photosensitive member rotation control method comprising:   15. The photosensitive member rotation control method according to claim 14, wherein in the braking step, the braking means applies a friction load to apply braking to rotation of the photosensitive member.   The braking step includes a disc brake that brakes rotation of a rotating shaft system that causes the braking means to rotate the photosensitive member, and applies braking to the rotation of the photosensitive member by the disc brake. The photoconductor rotation control method according to claim 14.   The said detection process detects the said acceleration by the said detection means detecting the mark which shows the some rotational position of the disk arrange | positioned at the said disk brake, The said acceleration is characterized by the above-mentioned. Photoconductor rotation control method.   The braking step includes a braking motor in which the braking means is disposed coaxially with the rotation shaft of the driving motor and applies braking to the rotation of the driving motor based on the acceleration detected by the detection means. 15. The photosensitive member rotation control method according to claim 14, wherein braking is applied to rotation of the photosensitive member by braking by the braking motor.   The braking step includes a braking motor in which the braking means is gear-connected to the driving motor and applies braking to the rotation of the photosensitive member based on the acceleration detected by the detecting means. 15. The photosensitive member rotation control method according to claim 14, wherein braking is applied to the rotation of the photosensitive member by braking.   A program causing a computer to execute the photosensitive member rotation control method according to any one of claims 13 to 19.

Images