JP2005086956A - Drive control method, drive control device, belt device, image forming apparatus, image scanner, program and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To constitute a position control system in a pulse motor drive system that can conduct exact and accurate control, even if a wrong input is generated to a detection signal by an influence of the connection of scales, dust and noise caused by the malfunction and the abnormality of a sensor, or the like. <P>SOLUTION: This drive control method controls the drive of a pulse motor so that a rotating body driven by the pulse motor rotates at isometric speed. The method detects the angle deviation of the rotating body, obtains the difference between the detected value of an angle deviation and the target value of a preset angle deviation, obtains the drive pulse frequency of a drive pulse signal for use in the drive of the pulse motor, on the basis of the difference of the detection value and the target value and a standard drive pulse frequency, and selects whether the difference of the detection value and the target value has been added to a standard drive pulse. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a drive control method using a pulse motor, a drive control device, a belt device, an image forming device, an image reading device, a program, and a recording medium.

As a prior art example, there is a speed control device for a rotating body, in a speed control system in which a feedback system using a pulse motor is constructed, which has means for interrupting rotational speed correction (for example, Patent Documents) 1).
JP 2002-136164 A

  Currently, there is a high-precision drive system in a pulse motor control system by constructing a feedback control loop for angular displacement in a drive control apparatus using a pulse motor. However, it is possible to drive with high accuracy, but when there is a malfunction in the detection signal, for example, when there is a failure of the detector or when the surface displacement sensor is used. However, there is a drawback in that accurate control cannot be performed and the drive accuracy is deteriorated.

  On the other hand, although the invention described in Patent Document 1 is described as having a means for interrupting the rotational speed correction in the speed control device for a rotating body in which a feedback system using a pulse motor is constructed, the description in the speed control system However, this invention cannot be applied to a more accurate position control system.

  The present invention has been made in view of the above circumstances, and is accurate and highly accurate even when there is an erroneous output in the detection signal due to the influence of scale connection, dust, noise due to sensor failure or abnormality, etc. It is an object to construct a position control system in a pulse motor drive system that can be controlled.

  Further, by using the present invention for an image carrier (photosensitive drum, transfer drum, photosensitive belt, transfer belt), transfer material conveyance belt drive system, and image reading apparatus of an image forming apparatus, the cost of parts is increased. The objective is to drive the drive system with high accuracy and obtain a high-quality image.

  In order to achieve this object, the invention described in claim 1 is a drive control method for controlling the driving of a pulse motor so that the rotating body driven using the pulse motor rotates at a constant angular velocity. Drive pulse signal used to drive the pulse motor based on the difference between the detected value of the angular displacement and the preset target value of the angular displacement and the standard drive pulse frequency. The drive pulse frequency is obtained, and it is possible to select whether or not to add the difference between the two to the standard drive pulse.

  According to the second aspect of the invention, in the first aspect of the invention, when there is an abnormality in the angular displacement detection result of the rotating body, the difference between the detected value of the angular displacement and a preset target value of the angular displacement is standardized. It is characterized by not being added to the drive pulse.

  The invention according to claim 3 is a drive control method for controlling the driving of the pulse motor so that the moving body driven by using the pulse motor moves at a constant speed. In a drive control method for obtaining a difference between a detection value and a target value of a preset displacement, and obtaining a drive pulse frequency of a drive pulse signal used for driving a pulse motor based on the difference between the two and a standard drive pulse frequency. It is possible to select whether or not to add the difference between the two to the standard drive pulse.

  According to a fourth aspect of the present invention, in the third aspect of the present invention, when there is an abnormality in the displacement detection result of the moving body, the difference between the detected displacement value and a preset target value for the displacement is used as a standard drive pulse. It is characterized by not adding.

  The invention according to claim 5 is a drive control device for controlling the driving of the pulse motor so that the rotating body driven by using the pulse motor rotates at an equiangular speed, wherein the detected value of the angular displacement of the rotating body is detected in advance. A means for obtaining a difference from a set target value of angular displacement, a means for obtaining a drive pulse frequency of a drive pulse signal used for driving a pulse motor based on the difference between the two and a standard drive pulse frequency, and a difference between the two. Means for selecting whether or not to add to the standard drive pulse.

  According to a sixth aspect of the present invention, in the invention of the fifth aspect, when there is an abnormality in the angular displacement detection result of the rotating body, the means for selecting whether to add the difference between the two to the standard drive pulse is It is characterized in that it is selected not to add the difference between the detected value of displacement and the preset target value of angular displacement to the standard drive pulse.

  The invention according to claim 7 is the invention according to claim 5 or 6, wherein the rotating body is a driving rotating body in which a belt is stretched between the rotating body and a driven rotating body. The driving of the pulse motor is controlled so as to rotate at the same time.

  In the invention according to claim 8, in the invention according to claim 5 or 6, the rotating body is a driven rotating body in which a belt is stretched between the rotating body for driving, and the driven rotating body has an equal angular velocity. The driving of the pulse motor is controlled so as to rotate at the same time.

  The invention according to claim 9 is a drive control device for controlling the driving of the pulse motor so that the moving body driven by using the pulse motor moves at a constant speed, wherein the detected value of the displacement of the moving body is set in advance. A means for determining the difference between the target value of the measured displacement and a means for determining the drive pulse frequency of the drive pulse signal used for driving the pulse motor based on the difference between the two and the standard drive pulse frequency. Means are provided for selecting whether or not to add to a pulse.

  According to a tenth aspect of the present invention, in the ninth aspect of the invention, when there is an abnormality in the displacement detection result of the moving body, it is possible to select whether or not to add the difference between the two to the standard drive pulse. It is characterized in that it is selected not to add the difference between the detected value and the preset target value of displacement to the standard drive pulse.

  According to an eleventh aspect of the present invention, in the ninth or tenth aspect of the present invention, the moving body is a belt that is stretched between the driving rotating body and the driven rotating body, and the belt moves at a constant speed. Thus, the drive of the pulse motor is controlled.

  A twelfth aspect of the invention according to the eleventh aspect of the invention is that in the eleventh aspect of the invention, the displacement detection device of the moving body is a surface sensor attached to the belt surface and having a joint with respect to one circumference of the belt. Is a joint.

  A thirteenth aspect of the invention is characterized in that, in the invention of any one of the fifth to twelfth aspects, there is no integral element in the means for obtaining the feedback drive pulse frequency.

  According to a fourteenth aspect of the present invention, there is provided a belt that is stretched over a plurality of support rotating bodies, a drive control device that controls driving of the belt, and a drive that drives the belt based on a drive pulse frequency output from the drive control device. 14. A belt device comprising a device, wherein the drive control device according to any one of claims 5 to 13 is used as a drive control device, and a means for detecting angular displacement or displacement is provided. And

  The invention described in claim 15 comprises an image carrier, a drive control device for controlling the drive of the image carrier, and a drive device for driving the image carrier based on the drive pulse frequency output from the drive control device. An image forming apparatus for forming an image by rotating an image carrier, wherein the drive control device according to any one of claims 5 to 14 is used as a drive control device to detect angular displacement or displacement. Means are provided.

  According to a sixteenth aspect of the invention, in the fifteenth aspect, the image carrier is a photosensitive drum.

  According to a seventeenth aspect of the present invention, in the fifteenth aspect, the image bearing member is a photosensitive belt.

  According to an eighteenth aspect, in the sixteenth aspect, the image carrier is a transfer drum.

  According to a nineteenth aspect of the present invention, in the fifteenth aspect, the image carrier is an intermediate transfer belt.

  According to a twentieth aspect of the present invention, a plurality of image carriers, a drive control device that controls driving of each image carrier, and a drive that drives each image carrier based on a drive pulse frequency output from the drive controller. An image forming apparatus for rotating a plurality of image carriers to form a color image, wherein the drive control apparatus according to any one of claims 5 to 13 is used as the drive control apparatus. It has the means to detect this.

  According to a twenty-first aspect of the present invention, a movable body including an optical system for image reading, a drive control device that controls driving of the movable body, and a drive pulse frequency output from the drive control device are driven. An image reading device that reads the image by moving the moving body along the surface of the image reading target, and uses the drive control device according to any one of claims 5 to 13 as a drive control device, Means for detecting angular displacement or displacement is provided.

  The invention according to claim 22 is a program for driving control for realizing, using a computer, driving control for controlling driving of a pulse motor so that a rotating body driven by the pulse motor rotates at an equiangular speed. Based on the function for obtaining the difference between the detected value of the angular displacement of the rotating body and the preset target value of the angular displacement, and the difference between the two and the standard drive pulse frequency, the drive pulse signal used for driving the pulse motor A function for obtaining the drive pulse frequency and a function for selecting whether or not to add the difference between the two to the standard drive pulse are realized by a computer.

  According to a twenty-third aspect of the present invention, there is provided a drive control program for realizing, using a computer, drive control for controlling drive of a pulse motor so that a moving body driven by the pulse motor moves at a constant speed. Thus, based on the function for obtaining the difference between the detected value of displacement of the moving body and a preset target value of displacement, and the difference between the two and the standard drive pulse frequency, the drive pulse signal used for driving the pulse motor The computer is realized with a function for obtaining a drive pulse frequency and a function for selecting whether or not to add a difference between the two to a standard drive pulse.

  According to a twenty-fourth aspect of the invention, there is provided a recording medium storing a drive control program, wherein the program according to the twenty-second or twenty-third aspect is executed by a computer.

  According to the present invention, a pulse motor drive capable of performing accurate and high-precision control even when there is an erroneous output in the detection signal due to the influence of scale connection, dust, noise due to sensor failure or abnormality, etc. The position control system in the system can be constructed, and the image carrier (photosensitive drum, transfer drum, photoconductor belt, transfer belt) of the image forming apparatus, the transfer material transport belt drive system, and the image reading device By using the present invention, it is possible to drive the drive system with high accuracy and to obtain a high-quality image without increasing the component cost.

  The best mode for carrying out the present invention will be described below in detail with reference to the accompanying drawings.

  FIG. 1 shows a rotary motor, a power transmission system, and a pulse motor as a rotational drive source in a first embodiment of the present invention. This 1st Example is an example of a rotary body drive control apparatus. In FIG. 1, reference numeral 1501 denotes a pulse motor as a rotational drive source for rotationally driving the rotating body. The rotational torque of the pulse motor 1501 is a shaft 1506 of the rotating body 1505 by a gear train 1503 and a timing belt 1504 constituting a power transmission system. Is transmitted to. The rotating body 1505 is firmly fixed to the shaft 1506. Reference numeral 1507 denotes an encoder as a state detection device that detects angular displacement of the rotating body 1505. The encoder 1507 is attached to the shaft 1506 of the rotating body 1505 via a coupling (not shown). Needless to say, the angular displacement of the shaft 1506 detected by the encoder 1507 is the same as the angular displacement of the rotating body 1505.

  FIG. 2 shows the configuration of a control system that digitally controls the angular displacement of the pulse motor 1501 based on the state detection signal of the rotating body 1505 (here, the output signal of the encoder 1507) in the first embodiment. In FIG. 2, reference numeral 1 denotes a microcomputer comprising a microprocessor 2, a read only memory (ROM) 3, and a random access memory (RAM) 4. The microprocessor 2, a read only memory (ROM) 3, and a random access memory (RAM). 4 are connected to each other via a bus 9.

  Reference numeral 5 denotes a command generating device that outputs a state command signal for commanding the target angular displacement of the rotating body 1505. The command generating device 5 generates an angular displacement command signal. The output side of the command generator 5 is also connected to the bus 9. Reference numeral 10 denotes a detection interface device that processes output pulses of the encoder 1507 and converts them into digital numerical values. This detection interface device 10 includes a counter that counts the output pulses of the encoder 1507, and the angular value of the rotating body 1505 is multiplied by a predetermined conversion number of the number of pulses versus diagonal displacement. Convert to displacement. Reference numeral 6 denotes an interface for driving the pulse motor. The interface 6 for driving the pulse motor uses the calculation result (control output) of the microcomputer 1 as a pulse signal (for example, operating a power semiconductor constituting the pulse motor drive device 7). Control signal). The pulse motor drive device 7 operates based on a pulse signal from the pulse motor drive interface 6 and rotationally drives the pulse motor. As a result, the rotary body 1505 is subjected to additional control to a predetermined angular displacement by the command generator 5. The angular displacement of the rotating body 1505 is detected by the encoder 1507 and the interface device 10 and is taken into the microcomputer 1 to repeat the above operation. Here, 11506 is a block diagram showing the rotating body, and 11510 is a block diagram showing the gear power transmission system 1503 and the timing belt power transmission system 1504 shown in FIG.

  Next, the driving control of the rotating body that controls the rotating body to a constant angular velocity state by controlling the rotational angular displacement of the rotating body 1505 by the pulse motor 1501 according to the present embodiment configured as described above is shown in FIG. This will be described with reference to the block configuration of the embodiment.

  In FIG. 3, reference numeral 801 denotes a control object including the entire rotating body drive system shown in FIG. 1 and the pulse motor drive interface 6, the pulse motor drive device 7 and the interface device 10 shown in FIG. The output of the interface device 10 that processes the output of the encoder 1507, that is, the angular displacement information P301 (i-1) of the rotating body 1505 is given to the arithmetic unit 304. The calculation unit 304 calculates a difference e (i) between the target angular displacement Ref (i) of the rotating body 1505 that is the control target value and the angular displacement P301 (i-1) of the rotating body. This e (i) is input to the control controller unit 305. The control controller unit 305 is constituted by a PI control system, for example. The e (i) calculated by the calculation unit 304 is integrated in the block 306, multiplied by a constant KI in the block 307, and given to the calculation unit 308. At the same time, e (i) calculated by the calculation unit 304 is multiplied by a constant KP in a block 309 and given to the calculation unit 308. The calculation unit 308 adds two input signals from the blocks 307 and 309 and gives the result to the feedback signal selection unit 311. The feedback signal selection unit receives the feedback determination signal, selects either the output from the calculation unit 308 or the constant 0, and supplies the selected value to the calculation unit 310. That is, when feedback is performed, the output of the calculation unit 308 is selected, and when feedback is not performed, the constant 0 is selected. Here, the feedback determination signal can be given as an arbitrary I / O signal that has received a sensor abnormality or the like, for example. Of course, it goes without saying that the output of the calculation unit 308 is selected when there is no abnormality, and the constant 0 is selected when there is an abnormality. Thereafter, a constant pulse input Repp_c is added in the calculation unit 310 to determine the drive pulse frequency u (i).

  The drive pulse frequency u (i) obtained by the calculation unit 310 is output to the pulse motor 1501 through the pulse motor drive interface 6 and the pulse motor drive device 7, and the rotating body 1505 rotates through the transmission system. The above loop operation is repeated. Here, the control controller unit 305 uses a PI control system as an example, but is not limited thereto. All the above operations are performed by numerical operations in the microcomputer 1 and can be easily realized. Also, Repp_c is the number of pulses uniquely determined based on the angular velocity of the rotating body and the reduction ratio of the speed reduction system. In the present invention, it is arbitrarily selected within a range in which the step-out phenomenon does not occur during motor driving. It is also possible. Also, Ref (i) can be easily obtained by integrating the target constant angular velocity of the rotating body.

  According to the first embodiment, when there is an abnormality, normal pulse motor driving is performed without performing feedback. Therefore, an erroneous output is generated in the detection signal due to the influence of noise or the like due to sensor failure or abnormality. Even in such a case, a position control system in the pulse motor drive system that can perform accurate and highly accurate control can be constructed.

  Next, a second embodiment of the present invention will be described. The second embodiment is an example of a belt conveyance control method to which the invention is applied.

  In FIG. 4, reference numeral 1501 denotes a pulse motor as a rotational drive source for rotationally driving the belt 1502. The rotational torque of the pulse motor 1501 is driven by a deceleration system that constitutes a power transmission system, for example, a belt driving j-axis 1506, It is transmitted to the drive roller 1505. The belt is looped around a driving roller 1505 and driven rollers 1510, 1511, 1512, 1513, 1514. Therefore, when the driving roller is rotated by the pulse motor, the belt moves accordingly.

  Reference numeral 1507 denotes an encoder as a state detection device that detects angular displacement of the driving roller 1505. The encoder 1507 is attached to a shaft 1506 of the driving roller 1505 via a coupling (not shown).

4 is driven and controlled in the control system shown in FIGS.
FIG. 5 shows the configuration of a control system that digitally controls the angular displacement of the pulse motor 1501 based on the state detection signal of the driving roller 1505 (here, the output signal of the encoder 1507) in the second embodiment. In FIG. 5, reference numeral 1 denotes a microcomputer comprising a microprocessor 2, a read only memory (ROM) 3, and a random access memory (RAM) 4. The microprocessor 2, a read only memory (ROM) 3, and a random access memory (RAM). 4 are connected to each other via a bus 9.

  Reference numeral 5 denotes a command generating device that outputs a state command signal for commanding the target angular displacement of the driving roller 1505. The command generating device 5 generates an angular displacement command signal. The output side of the command generator 5 is also connected to the bus 9. Reference numeral 10 denotes a detection interface device that processes output pulses of the encoder 1507 and converts them into digital numerical values. This detection interface device 10 is provided with a counter that counts the output pulses of the encoder 1507, and the angular value of the drive roller 1505 is multiplied by a predetermined conversion number of the number of pulses versus diagonal displacement. Convert to displacement. Reference numeral 6 denotes an interface for driving the pulse motor. The interface 6 for driving the pulse motor uses the calculation result (control output) of the microcomputer 1 as a pulse signal (for example, operating a power semiconductor constituting the pulse motor drive device 7). Control signal). The pulse motor drive device 7 operates based on a pulse signal from the pulse motor drive interface 6 and rotationally drives the pulse motor. As a result, the driving roller 1505 is subjected to an additional value control to a predetermined angular displacement by the command generator 5. As a result, the belt 1502 wound around the drive shaft 1505 is driven at a constant speed. The angular displacement of the driving roller 1505 is detected by the encoder 1507 and the interface device 10 and is taken into the microcomputer 1 to repeat the above operation. Here, 11506 is a block diagram showing the rotating body, and 11510 is a block diagram showing the timing belt power transmission system 1503 shown in FIG.

  Next, the belt driving control in which the belt is controlled to be in a constant speed state by controlling the rotational angular displacement of the driving roller 1505 by the pulse motor 1501 according to the present embodiment configured as described above is shown in FIG. The block configuration will be described. In FIG. 6, reference numeral 801 denotes a control object including the whole rotating body drive system shown in FIG. 4 and the pulse motor drive interface 6, the pulse motor drive device 7, and the interface device 10 shown in FIG.

  The output of the interface device 10 that processes the output of the encoder 1507, that is, the angular displacement information P301 (i-1) of the rotating body 1505 is given to the arithmetic unit 304. The calculation unit 304 calculates a difference e (i) between the target angular displacement Ref (i) of the rotating body 1505 that is the control target value and the angular displacement P301 (i-1) of the rotating body. This e (i) is input to the control controller unit 305.

  The control controller unit 305 is constituted by a PI control system, for example. The e (i) calculated by the calculation unit 304 is integrated in the block 306, multiplied by a constant KI in the block 307, and given to the calculation unit 308. At the same time, e (i) calculated by the calculation unit 304 is multiplied by a constant KP in a block 309 and given to the calculation unit 308. The calculation unit 308 adds the two input signals from the blocks 307 and 309 and gives the result to the feedback signal selection unit 311. The feedback signal selection unit receives the feedback determination signal, selects either the output from the calculation unit 308 or the constant 0, and supplies the selected value to the calculation unit 310. That is, when feedback is performed, the output of the calculation unit 308 is selected, and when feedback is not performed, the constant 0 is selected. Here, the feedback determination signal can be given as an arbitrary I / O signal that has received a sensor abnormality or the like, for example. Of course, it goes without saying that the output of the calculation unit 308 is selected when there is no abnormality, and the constant 0 is selected when there is an abnormality. Thereafter, a constant pulse input Repp_c is added in the calculation unit 310 to determine the drive pulse frequency u (i).

The drive pulse frequency u (i) obtained by the calculation unit 310 is output to the pulse motor 1501 through the pulse motor drive interface 6 and the pulse motor drive device 7, and the rotating body 1505 rotates through the transmission system. The above loop operation is repeated. Here, the control controller unit 305 uses a PI control system as an example, but is not limited thereto. All the above operations are performed by numerical operations in the microcomputer 1 and can be easily realized.
Also, Repp_c is the number of pulses uniquely determined based on the angular velocity of the rotating body and the reduction ratio of the speed reduction system. In the present invention, it is arbitrarily selected within a range in which the step-out phenomenon does not occur during motor driving. It is also possible. Also, Ref (i) can be easily obtained by integrating the target constant angular velocity of the rotating body.

  According to the second embodiment, when there is an abnormality, normal pulse motor driving is performed without performing feedback. Therefore, an erroneous output is generated in the detection signal due to the influence of noise or the like due to sensor failure or abnormality. Even in such a case, a belt position control system in the pulse motor drive system that can perform accurate and highly accurate control can be constructed.

  Next, a third embodiment of the present invention will be described. The third embodiment is an example of a belt conveyance control method.

  In FIG. 7, reference numeral 1501 denotes a pulse motor as a rotational drive source for rotationally driving the belt 1502, and the rotational torque of the pulse motor 1501 is driven by a speed reduction system that constitutes a power transmission system, for example, a belt driving j-axis 1506, It is transmitted to the drive roller 1505. The belt is looped around a driving roller 1505 and driven rollers 1510, 1511, 1512, 1513, 1514. Therefore, when the driving roller is rotated by the pulse motor, the belt moves accordingly.

  Reference numeral 1507 denotes an encoder as a state detection device that detects angular displacement of the driven roller 1510, and this encoder 1510 is attached to the shaft of the driven roller 1510 via a coupling 1516.

The belt conveying apparatus shown in FIG. 7 is driven and controlled in the control system shown in FIGS.
FIG. 8 shows the configuration of a control system that digitally controls the angular displacement of the pulse motor 1501 based on the state detection signal of the driven roller 1510 (here, the output signal of the encoder 1507) in the third embodiment. In FIG. 8, 1 is a microcomputer comprising a microprocessor 2, a read only memory (ROM) 3, and a random access memory (RAM) 4. The microprocessor 2, a read only memory (ROM) 3, and a random access memory (RAM). 4 are connected to each other via a bus 9.

  Reference numeral 5 denotes a command generator that outputs a state command signal for commanding the target angular displacement of the driven roller 1510. The command generator 5 generates an angular displacement command signal. The output side of the command generator 5 is also connected to the bus 9. Reference numeral 10 denotes a detection interface device that processes output pulses of the encoder 1507 and converts them into digital numerical values. The detection interface device 10 includes a counter that counts the output pulses of the encoder 1507, and the angular value of the driven roller 1510 is multiplied by a predetermined number of pulses and a conversion constant of diagonal displacement. Convert to displacement. Reference numeral 6 denotes an interface for driving the pulse motor. The interface 6 for driving the pulse motor uses the calculation result (control output) of the microcomputer 1 as a pulse signal (for example, operating a power semiconductor constituting the pulse motor drive device 7). Control signal). The pulse motor drive device 7 operates based on a pulse signal from the pulse motor drive interface 6 and rotationally drives the pulse motor. As a result, the driven roller 1510 is subjected to additional value control to a predetermined angular displacement by the command generator 5. As a result, the belt 1502 wound around the driven roller 1510 is driven at a constant speed. The angular displacement of the driven roller 1510 is detected by the encoder 1507 and the interface device 10 and is taken into the microcomputer 1 to repeat the above operation. Here, 11506 is a block diagram showing the belt conveying device, and 11510 is a block diagram showing the timing belt power transmission system 1503 shown in FIG.

  Next, with respect to the belt drive control in which the belt is controlled at a constant speed by controlling the rotational angular displacement of the driven roller 1510 by the pulse motor 1501 according to this embodiment configured as described above, this embodiment shown in FIG. The block configuration will be described. 9, reference numeral 801 denotes a control object including the entire drive system shown in FIG. 7 and the pulse motor drive interface 6, the pulse motor drive device 7 and the interface device 10 shown in FIG.

  The output of the interface device 10 that processes the output of the encoder 1507, that is, the angular displacement information P301 (i-1) of the rotating body 1505 is given to the arithmetic unit 304. The calculation unit 304 calculates a difference e (i) between the target angular displacement Ref (i) of the rotating body 1505 that is the control target value and the angular displacement P301 (i-1) of the rotating body. This e (i) is input to the control controller unit 305.

  The control controller unit 305 is constituted by a PI control system, for example. The e (i) calculated by the calculation unit 304 is integrated in the block 306, multiplied by a constant KI in the block 307, and given to the calculation unit 308. At the same time, e (i) calculated by the calculation unit 304 is multiplied by a constant KP in a block 309 and given to the calculation unit 308. The calculation unit 308 adds the two input signals from the blocks 307 and 309 and gives the result to the feedback signal selection unit 311. The feedback signal selection unit receives the feedback determination signal, selects either the output from the calculation unit 308 or the constant 0, and supplies the selected value to the calculation unit 310. That is, when feedback is performed, the output of the calculation unit 308 is selected, and when feedback is not performed, the constant 0 is selected. Here, the feedback determination signal can be given as an arbitrary I / O signal that has received a sensor abnormality or the like, for example. Of course, it goes without saying that the output of the calculation unit 308 is selected when there is no abnormality, and the constant 0 is selected when there is an abnormality. Thereafter, a constant pulse input Repp_c is added in the calculation unit 310 to determine the drive pulse frequency u (i).

The drive pulse frequency u (i) obtained by the calculation unit 310 is output to the pulse motor 1501 via the pulse motor drive interface 6 and the pulse motor drive device 7, and the drive shaft 1505 rotates via the transmission system. The above loop operation is repeated. Here, the control controller unit 305 uses a PI control system as an example, but is not limited thereto. All the above operations are performed by numerical operations in the microcomputer 1 and can be easily realized.
In addition, Refp_c is the number of pulses uniquely determined based on the belt speed, the driving roller angular speed based on the belt driving radius, and the reduction ratio of the speed reduction system. It is also possible to select arbitrarily within the range where the step-out phenomenon does not occur. Also, Ref (i) can be easily obtained by integrating the equal angular velocity of the driven roller.

  According to the third embodiment, when there is an abnormality, normal pulse motor driving is performed without performing feedback. Therefore, an erroneous output is generated in the detection signal due to the influence of noise or the like due to sensor failure or abnormality. Even in such a case, it is possible to construct a belt conveyance control device in a pulse motor drive system that can perform accurate and highly accurate control.

  Next, a fourth embodiment of the present invention will be described. The fourth embodiment is an example of a belt conveyance control method.

  In FIG. 10, reference numeral 1501 denotes a pulse motor as a rotational drive source for rotationally driving a belt 1502, and the rotational torque of the pulse motor 1501 is driven by a speed reduction belt constituting a power transmission system, for example, a belt drive shaft 1506 by a timing belt 1503. It is transmitted to the roller 1505. The belt is looped around a driving roller 1505 and driven rollers 1510, 1511, 1512, 1513, 1514. Therefore, when the driving roller is rotated by the pulse motor, the belt moves accordingly.

  Reference numeral 1507 denotes a marker sensor installed at a position facing the marker 1508. The marker sensor 1507 is composed of a photo interrupter or the like, and outputs a digital signal “1” when the marker 1508 reaches the detection position and faces the marker sensor 1507, and the marker 1508 and the marker 1508 are detected at the detection position. When a part between the two points arrives and opposes this part, the digital signal “0” is output. By counting the digital signal from the marker sensor 1507, the displacement of the belt 1502 surface can be detected. Although not shown here, the marker always has a break, and the marker sensor cannot output a signal at a predetermined interval.

The belt conveying apparatus shown in FIG. 10 is driven and controlled in the control system shown in FIGS.
FIG. 11 shows the configuration of a control system for digitally controlling the angular displacement of the pulse motor 1501 based on the state detection signal of the belt 1502 (here, the output signal of the encoder 1507) in the fourth embodiment. In FIG. 11, reference numeral 1 denotes a microcomputer comprising a microprocessor 2, a read only memory (ROM) 3, and a random access memory (RAM) 4. The microprocessor 2, a read only memory (ROM) 3, and a random access memory (RAM). 4 are connected to each other via a bus 9.

  Reference numeral 5 denotes a command generation device that outputs a state command signal for commanding the target displacement of the belt 1502, and this command generation device 5 generates a displacement command signal. The output side of the command generator 5 is also connected to the bus 9. Reference numeral 10 denotes a detection interface device that processes the output pulses of the marker sensor 1507 and converts them into digital numerical values. The detection interface device 10 includes a counter that counts the output pulses of the marker sensor 1507, and the displacement of the belt 1502 is obtained by multiplying the numerical value counted by the counter by a predetermined conversion number of pulses versus displacement. Convert. Reference numeral 6 denotes an interface for driving the pulse motor. The interface 6 for driving the pulse motor uses the calculation result (control output) of the microcomputer 1 as a pulse signal (for example, operating a power semiconductor constituting the pulse motor drive device 7). Control signal). The pulse motor drive device 7 operates based on a pulse signal from the pulse motor drive interface 6 and rotationally drives the pulse motor. As a result, the belt 1502 is subjected to additional value control to a predetermined displacement by the command generator 5. That is, the belt 1502 is driven at a constant speed. The displacement of the belt 1502 is detected by the marker sensor 1507 and the interface device 10 and is taken into the microcomputer 1 to repeat the above operation. Here, 11506 is a block diagram showing the belt conveying device, and 11510 is a block diagram showing the timing belt power transmission system 1503 shown in FIG.

  Next, the drive control of the belt in which the belt is controlled at a constant speed by controlling the rotational angular displacement of the driven roller 1510 by the pulse motor 1501 according to the present embodiment configured as described above is shown in FIG. The block configuration will be described. In FIG. 12, reference numeral 801 denotes a control object including the entire drive system shown in FIG. 10 and the pulse motor driving interface 6, the pulse motor drive device 7 and the interface device 10 shown in FIG.

  The output of the interface device 10 that processes the output of the marker sensor 1507, that is, the displacement information P301 (i-1) of the belt 1502 is given to the arithmetic unit 304. The calculation unit 304 calculates a difference e (i) between the target displacement Ref (i) of the belt 1502 and the measured displacement P301 (i-1) of the belt with the control target value. This e (i) is input to the control controller unit 305.

  The control controller unit 305 is constituted by a PI control system, for example. The e (i) calculated by the calculation unit 304 is integrated in the block 306, multiplied by a constant KI in the block 307, and given to the calculation unit 308. At the same time, e (i) calculated by the calculation unit 304 is multiplied by a constant KP in a block 309 and given to the calculation unit 308. The calculation unit 308 adds the two input signals from the blocks 307 and 309 and gives the result to the feedback signal selection unit 311. The feedback signal selection unit receives the feedback determination signal, selects either the output from the calculation unit 308 or the constant 0, and supplies the selected value to the calculation unit 310. That is, when feedback is performed, the output of the calculation unit 308 is selected, and when feedback is not performed, the constant 0 is selected. Here, the feedback determination signal can be given as an arbitrary I / O signal that has received a break in the marker sensor, an abnormality in the sensor, or the like. Of course, it goes without saying that the output of the calculation unit 308 is selected when there is no abnormality, and the constant 0 is selected when there is an abnormality. Thereafter, a constant pulse input Repp_c is added in the calculation unit 310 to determine the drive pulse frequency u (i).

The drive pulse frequency u (i) obtained by the calculation unit 310 is output to the pulse motor 1501 via the pulse motor drive interface 6 and the pulse motor drive device 7, and the drive shaft 1505 rotates via the transmission system. The above loop operation is repeated. Here, the control controller unit 305 uses a PI control system as an example, but is not limited thereto. All the above operations are performed by numerical operations in the microcomputer 1 and can be easily realized.
In addition, Refp_c is the number of pulses uniquely determined based on the belt speed, the driving roller angular speed based on the belt driving radius, and the reduction ratio of the speed reduction system. It is also possible to select arbitrarily within the range where the step-out phenomenon does not occur. Ref (i) can be easily obtained by integrating the constant velocity of the belt.

  According to the fourth embodiment, since the normal pulse motor drive is performed without performing feedback when there is a break in the marker sensor or the sensor is abnormal, the break in the marker sensor or the failure or abnormality of the sensor is detected. It is possible to construct a belt conveyance control device in a pulse motor control system using a belt surface sensor that can perform accurate and high-precision control even when there is an erroneous output in the detection signal due to the influence of noise, etc. it can.

  Next, a fifth embodiment of the present invention will be described. The fifth embodiment will be described using the first embodiment, but the present invention is also applicable to the second to fourth embodiments.

  FIG. 13 shows the configuration of a control system for controlling the rotating body to a constant angular velocity state by controlling the rotational angular displacement of the rotating body 1505 by the pulse motor 1501 in the fifth embodiment. In FIG. 13, the same reference numerals as those in FIG. 3 denote the same parts, and the description thereof is omitted.

  A difference e (i) between the target angular displacement Ref (i) of the rotating body 1505 and the angular displacement P301 (i-1) of the rotating body is input to the control controller unit 401. The control controller unit 401 is configured only by a system without an integral element, for example, a proportional control system. The calculation result is given to the calculation unit 310, and a constant pulse input Repp_c is added to the calculation unit 310 to determine the drive pulse frequency u (i).

  When an integral component is included in the control system, a large error may be included in the switching timing when the feedback pulse is added to the drive pulse or not added. Therefore, a control system is constructed with a system that does not include an integral element so that there is no danger. The control system is not limited to proportional control, and there is no problem as long as the system does not include an integral element in other configurations.

  As described above, according to the fifth embodiment, the feedback system is constructed by a system that does not include an integration element. Therefore, even when a detection signal is erroneously output due to the influence of noise or the like due to sensor failure or abnormality, the feedback system is accurate. Therefore, it is possible to construct a position control system in the pulse motor drive system capable of highly accurate control more safely.

  FIG. 14 shows a sixth embodiment of the present invention. The sixth embodiment is an example of an image forming apparatus composed of a color copying machine.

  In FIG. 14, reference numeral 10 denotes an apparatus main body of the sixth embodiment. The apparatus main body 10 includes a drum-shaped photosensitive member (photosensitive drum) 12 as an image carrier, slightly to the right of the center in the outer case 11. Around the photosensitive member 12, a rotary developing device 14, an intermediate transfer unit 15, and a cleaning device 16 as developing means are sequentially arranged from a charger 13 installed on the photosensitive member 12 in the rotation direction (counterclockwise direction) indicated by an arrow. The static eliminator 17 is disposed.

  On these charger 13, rotary developing device 14, cleaning device 16, and static eliminator 17, an optical writing device as an exposure unit, for example, a laser writing device 18 is installed. The rotary developing device 14 includes developing devices 20A, 20B, 20C, and 20D each having a developing roller 21 that stores toner of each color of yellow, magenta, cyan, and black. The developing units 20A, 20B, 20C, and 20D are selectively moved to a developing position that faces the outer periphery of the photoconductor 12.

  In the intermediate transfer unit 15, an endless intermediate transfer member as an image carrier, for example, an intermediate transfer belt 24, is wound around a plurality of rollers 23, and the intermediate transfer belt 24 is in contact with the photosensitive member 12. A transfer device 25 is installed inside the intermediate transfer belt 24, and a transfer device 26 and a cleaning device 27 are installed outside the intermediate transfer belt 24. The cleaning device 27 is provided so as to be able to contact with and separate from the intermediate transfer belt 24.

  The laser writing device 18 receives an image signal of each color from the image reading device 29 via an image processing unit (not shown), and sequentially applies the laser light L modulated by the image signal of each color to the uniformly charged photoconductor 12. Irradiation exposes the photoreceptor 12 to form an electrostatic latent image on the photoreceptor 12. The image reading device 29 color-separates and reads the image of the document G set on the document table 30 provided on the upper surface of the apparatus body 10 and converts it into an electrical image signal. The recording medium conveyance path 32 conveys a recording medium such as a sheet from right to left. In the recording medium conveyance path 32, a registration roller 33 is installed in front of the intermediate transfer unit 15 and the transfer device 26, and a conveyance belt 34, a fixing device 35, and a paper discharge roller 36 are disposed downstream of the intermediate transfer unit 15 and the transfer device 26. Is arranged.

  The apparatus main body 10 is placed on the sheet feeding device 50. A plurality of paper feed cassettes 51 are provided in multiple stages in the paper feed device 50, and any one of the paper feed rollers 52 is selectively driven to send a recording medium from any one of the paper feed cassettes 51. . This recording medium is conveyed to the recording medium conveyance path 32 through the automatic paper feeding path 37 in the apparatus main body 10. A manual feed tray 38 is provided on the right side of the apparatus main body 10 so that it can be opened and closed. A recording medium inserted from the manual feed tray 38 is conveyed to the recording medium conveyance path 32 through a manual paper feed path 39 in the apparatus main body 10. The A paper discharge tray (not shown) is detachably attached to the left side of the apparatus main body 10, and the recording medium discharged by the paper discharge roller 36 through the recording medium conveyance path 32 is accommodated in the paper discharge tray.

  In the sixth embodiment, when color copying is performed, when the original G is set on the original table 30 and a start switch (not shown) is pressed, the copying operation is started. First, the image reading device 29 separates and reads the image of the document G on the document table 30. At the same time, the recording medium is selectively sent out from the paper feeding cassette 51 in the paper feeding device 50 by the paper feeding roller 52, and the recording medium hits the registration roller 33 through the automatic paper feeding path 37 and the recording medium conveyance path 32 and stops. .

  The photosensitive member 12 rotates counterclockwise, and the intermediate transfer belt 24 rotates clockwise by the rotation of the driving roller of the plurality of rollers 23. The photosensitive member 12 is uniformly charged by the charger 13 as it rotates, and laser light modulated by an image signal of the first color applied from the image reading device 29 to the laser writing device 18 via the image processing unit is laser-induced. Irradiation from the writing device 18 forms an electrostatic latent image.

  The electrostatic latent image on the photosensitive member 12 is developed by the first color developing device 20A of the rotary developing device 14 to become a first color image. The first color image on the photosensitive member 12 is intermediately transferred by the transfer device 25. Transferred to the belt 24. The photoconductor 12 is cleaned by the cleaning device 16 after the transfer of the first color image to remove the residual toner, and is neutralized by the static eliminator 17.

  Subsequently, the photosensitive member 12 is uniformly charged by the charger 13, and laser light modulated by the image signal of the second color applied from the image reading device 29 to the laser writing device 18 through the image processing unit is written into the laser beam. Irradiation from the device 18 forms an electrostatic latent image. The electrostatic latent image on the photoconductor 12 is developed by the second color developing device 20B of the rotary developing device 14 to become a second color image, and the second color image on the photoconductor 12 is intermediately transferred by the transfer device 25. The first color image is transferred onto the belt 24 in a superimposed manner. The photosensitive member 12 is cleaned by the cleaning device 16 after the transfer of the image of the second color to remove the residual toner, and is neutralized by the static eliminator 17.

  Next, the photosensitive member 12 is uniformly charged by the charger 13, and laser light modulated by the image signal of the third color applied from the image reading device 29 to the laser writing device 18 through the image processing unit is written into the laser beam. Irradiation from the device 18 forms an electrostatic latent image. The electrostatic latent image on the photoconductor 12 is developed by the third color developing device 20C of the rotary developing device 14 to be an image of the third color, and the image of the third color on the photoconductor 12 is intermediately transferred by the transfer device 25. The first color image and the second color image are superimposed and transferred onto the belt 24. The photosensitive member 12 is cleaned by the cleaning device 16 after the transfer of the image of the third color, the residual toner is removed, and the charge is removed by the charge eliminator 17.

  Further, the photosensitive member 12 is uniformly charged by the charger 13, and the laser beam modulated by the image signal of the fourth color applied from the image reading device 29 to the laser writing device 18 via the image processing unit is applied to the laser writing device. Irradiation from 18 forms an electrostatic latent image. The electrostatic latent image on the photosensitive member 12 is developed by the fourth color developing device 20D of the rotary developing device 14 to become a fourth color image. The fourth color image on the photosensitive member 12 is intermediately transferred by the transfer device 25. A full-color image is formed on the belt 24 by being superimposed on the first color image, the second color image, and the third color image. The photoconductor 12 is cleaned by the cleaning device 16 after the transfer of the image of the fourth color, the residual toner is removed, and the charge is removed by the charge eliminator 17.

  Then, the registration roller 33 is rotated at a timing to send out a recording medium, and a full-color image on the intermediate transfer belt 24 is transferred to the recording medium by the transfer device 26. This recording medium is transported by the transport belt 34, the full color image is fixed by the fixing device 35, and is discharged to the paper discharge tray by the paper discharge roller 36. Further, the intermediate transfer belt 24 is cleaned by the cleaning device 27 after the transfer of the full color image to remove the residual toner.

The operation for forming a four-color superimposed image has been described above. In the case of forming a three-color superimposed image, three different single-color images are sequentially formed on the photosensitive member 12 and transferred onto the intermediate transfer belt 24 in a superimposed manner. In the case where a two-color superimposed image is formed after being collectively transferred to a recording medium, two different single-color images are sequentially formed on the photoreceptor 12 and transferred after being superimposed and transferred onto the intermediate transfer belt 24. It is transferred to the medium all at once. When a single color image is formed, one single color image is formed on the photoconductor 12 and transferred onto the intermediate transfer belt 24 and then transferred to a recording medium.
In such a color copying machine, the rotational accuracy of the image carriers 12 and 24 greatly affects the quality of the final image, and higher-precision drive control of the image carriers 12 and 24 is desired.

  Therefore, in the sixth embodiment, the drive control of the photosensitive drum 12 is performed by the rotating body drive control device of any one of the first to fifth embodiments and / or the intermediate transfer. The drive control of the belt 24 is performed by the belt conveyance control device of any one of the first to fifth embodiments.

  According to the sixth embodiment, the drive control of the image carriers 12 and 24 is performed by the drive control device of any one of the first to fifth embodiments. This improves the accuracy of the image bearing member and makes it possible to perform high-accuracy image carrier drive control and to obtain a high-quality image.

  FIG. 15 shows a seventh embodiment of the present invention. The seventh embodiment is an example of an image forming apparatus composed of a color copying machine.

  A photoconductor 101 as an image carrier is a photoconductor belt in which a photosensitive layer such as an organic optical semiconductor (OPC) is formed in a thin film shape on the outer peripheral surface of a closed loop Ni belt base material. The photoconductor 101 is supported by three photoconductor transport rollers 102 to 104 and is rotated in the direction of arrow A by a drive motor (not shown).

  Around the photosensitive member 101, in the order of rotation of the photosensitive member 101 indicated by an arrow A, a charger 105, an exposure optical system (hereinafter referred to as LSU) 106 as an exposure unit, black, yellow, magenta, and cyan developing devices. 107 to 110, an intermediate transfer unit 111, a photosensitive member cleaning unit 112, and a static eliminator 113 are provided. The charger 105 is applied with a high voltage of about −4 to 5 kV from a power supply device (not shown), and charges a portion of the photoconductor 101 facing the charger 105 to give a uniform charging potential.

  The LSU 106 sequentially modulates light intensity or pulse width of each color image signal from a gradation converting means (not shown) by a laser drive circuit (not shown), and a semiconductor laser (not shown) using the modulated signal. , The exposure light beam 114 is obtained, and the photosensitive member 101 is scanned with the exposure light beam 114 to sequentially form electrostatic latent images corresponding to the image signals of the respective colors on the photosensitive member 101. The seam sensor 115 detects the joint of the photoconductor 101 formed in a loop shape. When the seam sensor 115 detects the seam of the photoconductor 101, the seam of the photoconductor 101 is avoided and each color is detected. The timing controller 116 controls the light emission timing of the LSU 106 so that the electrostatic latent image forming positions are the same.

  Each of the developing devices 107 to 110 stores toner corresponding to each developing color, and is selectively applied to the photosensitive member 101 at a timing corresponding to the electrostatic latent image corresponding to the image signal of each color on the photosensitive member 101. The electrostatic latent image on the photosensitive member 101 is abutted and developed with toner to form an image of each color, thereby forming a full-color image by a four-color superimposed image.

  The intermediate transfer unit 111 includes a transfer drum 117 as an intermediate transfer member in which a belt-like sheet made of a conductive resin or the like is wound around a metal tube such as aluminum, and an intermediate transfer member cleaning in which rubber or the like is formed in a blade shape. The intermediate transfer member cleaning unit 118 is separated from the intermediate transfer member 117 while the four-color superimposed image is formed on the intermediate transfer member 117. The intermediate transfer member cleaning unit 118 contacts the intermediate transfer member 117 only when the intermediate transfer member 117 is cleaned, and removes toner remaining without being transferred from the intermediate transfer member 117 to the recording paper 119 as a recording medium. The recording sheets are sent one by one from the recording sheet cassette 120 to the sheet conveying path 122 by the sheet feeding roller 121.

The transfer unit 123 serving as a transfer unit transfers the full color image on the intermediate transfer body 117 to the recording paper 119. The transfer unit 124 in which conductive rubber or the like is formed in a belt shape, and the transfer unit 123 on the intermediate transfer body 117. A transfer device 125 that applies a transfer bias for transferring a full color image to the recording paper 119 to the intermediate transfer body 117, and the recording paper 119 is electrostatically applied to the intermediate transfer body 117 after the full color image is transferred to the recording paper 119. The separator 126 is configured to apply a bias to the intermediate transfer member 117 so as to prevent sticking.
The fixing device 127 includes a heat roller 128 having a heat source therein and a pressure roller 129. The full-color image transferred onto the recording paper 119 is rotated between recording rollers of the heat roller 128 and the pressure roller 129. Accordingly, pressure and heat are applied to the recording paper 119 to fix the full-color image on the recording paper 119 to form a full-color image. The operation of the sixth embodiment configured as described above will be described below. Here, the description will proceed assuming that the development of the electrostatic latent image is performed in the order of black, cyan, magenta, and yellow.

  The photosensitive member 101 and the intermediate transfer member 117 are driven in the directions of arrows A and B by respective driving sources (not shown). In this state, first, a high voltage of about −4 to 5 kV is applied to the charger 105 from a power supply device (not shown), and the charger 105 uniformly charges the surface of the photoreceptor 101 to about −700V. Next, after the seam sensor 115 detects the seam of the photoconductor 101 and after a predetermined time has passed so as to avoid the seam of the photoconductor 101, the laser beam corresponding to the black image signal from the LSU 106 is applied to the photoconductor 101. The exposure light beam 114 is irradiated, and the photosensitive member 101 loses the charge of the portion irradiated with the exposure light beam 114 to form an electrostatic latent image.

  On the other hand, the black developing device 107 is brought into contact with the photosensitive member 101 at a predetermined timing. The black toner in the black developing device 107 is given a negative charge in advance, and the black toner adheres only to a portion (electrostatic latent image portion) where the charge has disappeared due to the irradiation of the exposure light beam 114 on the photoreceptor 101. Development is performed by a so-called negative-positive process. The black toner image formed on the surface of the photosensitive member 101 by the black developing unit 107 is transferred to the intermediate transfer member 117. Residual toner that has not been transferred from the photoconductor 101 to the intermediate transfer body 117 is removed by the photoconductor cleaning means 112, and the charge on the photoconductor 101 is removed by the static eliminator 113.

  Next, the charger 105 uniformly charges the surface of the photoreceptor 101 to about −700V. Then, after the seam sensor 115 detects the seam of the photoconductor 101, a predetermined time elapses so as to avoid the seam of the photoconductor 101, and exposure of the laser beam corresponding to the cyan image signal from the LSU 106 is performed on the photoconductor 101. The photosensitive member 101 is irradiated with the light beam 114 and the charge of the portion irradiated with the exposure light beam 114 disappears to form an electrostatic latent image.

  On the other hand, the cyan developing unit 108 is brought into contact with the photosensitive member 101 at a predetermined timing. The cyan toner in the cyan developing unit 108 is given a negative charge in advance, and the cyan toner adheres only to the portion (electrostatic latent image portion) where the charge disappears due to the irradiation of the exposure light beam 114 on the photosensitive member 101, Development is performed by a so-called negative-positive process. The cyan toner image formed on the surface of the photosensitive member 101 by the cyan developing unit 108 is transferred onto the intermediate transfer member 117 so as to overlap the black toner image. Residual toner that has not been transferred from the photoconductor 101 to the intermediate transfer body 117 is removed by the photoconductor cleaning means 112, and the charge on the photoconductor 101 is removed by the static eliminator 113.

  Next, the charger 105 uniformly charges the surface of the photoreceptor 101 to about −700V. Then, after the seam sensor 115 detects the seam of the photoconductor 101 and after a certain time has passed so as to avoid the seam of the photoconductor 101, exposure of the laser beam corresponding to the magenta image signal from the LSU 106 to the photoconductor 101 is performed. The photosensitive member 101 is irradiated with the light beam 114 and the charge of the portion irradiated with the exposure light beam 114 disappears to form an electrostatic latent image.

  On the other hand, a magenta developing device 109 is brought into contact with the photosensitive member 101 at a predetermined timing. The magenta toner in the magenta developing device 109 is previously given a negative charge, and the magenta toner adheres only to the portion (electrostatic latent image portion) where the charge has disappeared due to the irradiation of the exposure light beam 114 on the photoreceptor 101. Development is performed by a so-called negative-positive process. The magenta toner image formed on the surface of the photosensitive member 101 by the magenta developing unit 109 is transferred onto the intermediate transfer member 117 so as to overlap the black toner image and the cyan toner image. Residual toner that has not been transferred from the photoconductor 101 to the intermediate transfer body 117 is removed by the photoconductor cleaning means 112, and the charge on the photoconductor 101 is removed by the static eliminator 113.

  Further, the charger 105 uniformly charges the surface of the photoreceptor 101 to about −700V. Then, after the seam sensor 115 detects the joint of the photoconductor 101, a predetermined time elapses so as to avoid the joint of the photoconductor 101, and the photoconductor 101 is exposed to the laser beam corresponding to the yellow image signal from the LSU 106. The photosensitive member 101 is irradiated with the light beam 114 and the charge of the portion irradiated with the exposure light beam 114 disappears to form an electrostatic latent image.

  On the other hand, the yellow developing device 110 contacts the photoconductor 101 at a predetermined timing. The yellow toner in the yellow developing device 110 is given a negative charge in advance, and the yellow toner adheres only to the portion (electrostatic latent image portion) where the charge has disappeared due to the irradiation of the exposure light beam 114 on the photoreceptor 101. Development is performed by a so-called negative-positive process. The yellow toner image formed on the surface of the photosensitive member 101 by the yellow developing device 110 is transferred onto the intermediate transfer member 117 so as to overlap the black toner image, the cyan toner image, and the magenta toner image, and a full-color image is formed on the intermediate transfer member 117. It is formed. Residual toner that has not been transferred from the photoconductor 101 to the intermediate transfer body 117 is removed by the photoconductor cleaning means 112, and the charge on the photoconductor 101 is removed by the static eliminator 113.

  In the full-color image formed on the intermediate transfer body 117, the transfer unit 123 that has been separated from the intermediate transfer body 117 so far contacts the intermediate transfer body 117, and a high voltage of about +1 kV is applied to the transfer device 125 by a power supply device (see FIG. (Not shown), the transfer device 125 collectively transfers the recording paper 119 transported along the paper transport path 122 from the recording paper cassette 120. In addition, a voltage is applied from the power supply device to the separator 126 so that an electrostatic force attracting the recording paper 119 acts, and the recording paper 119 is peeled off from the intermediate transfer body 117. Subsequently, the recording paper 119 is sent to the fixing device 127, where the full color image is fixed by the nipping pressure between the heat roller 128 and the pressure roller 129 and the heat of the heat roller 128, and the paper discharge tray 130 discharges the paper. It is discharged to 131.

  Further, residual toner on the intermediate transfer member 117 that has not been transferred onto the recording paper 119 by the transfer unit 123 is removed by the intermediate transfer member cleaning means 118. The intermediate transfer member cleaning unit 118 is located away from the intermediate transfer member 117 until a full color image is obtained. After the full color image is transferred to the recording paper 119, the intermediate transfer member 117 comes into contact with the intermediate transfer member 117 and is on the intermediate transfer member 117. Remove residual toner. The full color image formation for one sheet is completed by the series of operations described above.

  In such a color copying machine, the rotational accuracy of the image carriers 101 and 117 greatly affects the quality of the final image, and higher-precision drive control of the image carriers 101 and 117 is desired. Therefore, in the seventh embodiment, the drive control of the photosensitive belt 101 is performed by the belt conveyance control device of any one of the first to fifth embodiments and / or the transfer drum 117. The drive control is performed by the rotating body drive control device according to any one of the first to fifth embodiments.

  According to the seventh embodiment, since the drive control of the image carriers 101 and 117 is performed by any one of the drive control devices of the first to fifth embodiments, the drive control of the image carrier is performed. This improves the accuracy of the image bearing member and makes it possible to perform high-accuracy image carrier drive control and to obtain a high-quality image.

  FIG. 16 shows an eighth embodiment of the present invention. The eighth embodiment is an example of a tandem image forming apparatus.

  In the eighth embodiment, a plurality of images each forming a plurality of colors, for example, black (hereinafter referred to as Bk), magenta (hereinafter referred to as M), yellow (hereinafter referred to as Y), and cyan (hereinafter referred to as C) images. The image forming units 221Bk, 221M, 221Y, and 221C are arranged in the vertical direction. The image forming units 221Bk, 221M, 221Y, and 221C are image bearing members 222Bk, 222M, 222Y and 222C each formed of a drum-shaped photoconductor, and a charging device. (For example, contact charging device) 223Bk, 223M, 223Y, 223C, developing device 224Bk, 224M, 224Y, 224C, cleaning device 225Bk, 225M, 225Y, 225C, etc.

  The photoconductors 222Bk, 222M, 222Y, and 222C are arranged in the vertical direction so as to face the endless transport transfer belt 226, and are driven to rotate at the same peripheral speed as the transport transfer belt 226. The photoconductors 222Bk, 222M, 222Y, and 222C are uniformly charged by the charging devices 223Bk, 223M, 223Y, and 223C, respectively, and then exposed by the exposure units 227Bk, 227M, 227Y, and 227C, which are optical writing devices, respectively. An electrostatic latent image is formed.

  The optical writing devices 227Bk, 227M, 227Y, and 227C respectively drive the semiconductor laser by the semiconductor laser driving circuit based on the image signals of Y, M, C, and Bk colors, and convert the laser beam from the semiconductor laser to the polygon mirrors 229Bk, 229M, 229Y and 229C are deflected and scanned, and the respective laser beams from the polygon mirrors 229Bk, 229M, 229Y, and 229C are imaged on the photosensitive members 222Bk, 222M, 222Y, and 222C via fθ lenses and mirrors (not shown), thereby providing photosensitive. The bodies 222Bk, 222M, 222Y, and 222C are exposed to form an electrostatic latent image.

  The electrostatic latent images on the photoreceptors 222Bk, 222M, 222Y, and 222C are developed by the developing devices 224Bk, 224M, 224Y, and 224C, respectively, and become toner images of Bk, M, Y, and C colors. Accordingly, the charging devices 223Bk, 223M, 223Y, 223C, the optical writing devices 227Bk, 227M, 227Y, 227C and the developing devices 224Bk, 224M, 224Y, 224C are Bk, M, Y on the photoreceptors 222Bk, 222M, 222Y, 222C. , C constitutes image forming means for forming each color image (toner image).

  On the other hand, transfer paper such as plain paper and OHP sheet is fed to a registration roller 231 along a transfer paper transport path from a paper feeding device 230 configured using a paper feed cassette installed at the bottom of the present embodiment. The registration roller 231 conveys the transfer paper in synchronization with the toner image on the photoconductor 222Bk in the first color image forming unit (image forming unit that first transfers the image on the photoconductor to the transfer paper) 221Bk. 226 and the photosensitive member 222Bk.

  The conveyance transfer belt 226 is stretched around a driving roller 232 and a driven roller 233 arranged in the vertical direction, and the driving roller 232 is driven to rotate by a driving unit (not shown) so that the conveyance transfer belt 226 is photoreceptors 222Bk, 222M, 222Y, 222C. Rotate at the same peripheral speed. The transfer paper delivered from the registration roller 231 is conveyed by a conveyance transfer belt 226, and toner images of Bk, M, Y, and C colors on the photosensitive members 222Bk, 222M, 222Y, and 222C are transferred to a transfer unit 234Bk that includes a corona discharger. 234M, 234Y, and 234C are sequentially superimposed and transferred by the action of the electric field formed by 234M, 234Y, and 234C, and at the same time, a full-color image is formed, and at the same time, is electrostatically attracted to the transport transfer belt 226 and reliably transported.

  The transfer paper is gradually electrified by a separation means 236 comprising a separation charger and separated from the conveyance transfer belt 226, and then a full color image is fixed by a fixing device 237, and is provided on the upper part of the present embodiment by a paper discharge roller 238. The paper is discharged to the paper discharge unit 239. In addition, the photosensitive members 222Bk, 222M, 222Y, and 222C are cleaned by the cleaning devices 225Bk, 225M, 225Y, and 225C after the toner image is transferred to prepare for the next image forming operation.

  In such a color copying machine, the driving accuracy of the image carriers 222Bk, 222M, 222Y, and 222C and the transfer material transport belt 226 greatly affects the quality of the final image, and the image carriers 222Bk, 222M, and 222Y with higher accuracy. , 222C and the transfer control of the transfer material conveying belt 226 are desired. Therefore, in the ninth embodiment, drive control of the photosensitive drums 222Bk, 222M, 222Y, and 222C is performed by any one of the rotating body drive control devices of the first to sixth embodiments. Alternatively, the drive control of the transfer material conveyance belt 226 is performed by the belt conveyance control device according to any one of the first to sixth embodiments.

  According to the eighth embodiment, in an image forming apparatus that forms a color image by rotating a plurality of image carriers 222Bk, 222M, 222Y, 222C, the plurality of image carriers 222Bk, 222M, 222Y, 222C Since each drive control is performed by any one of the rotating body drive control devices of the first to fifth embodiments, the accuracy of the drive control of the image carrier is improved, and a plurality of image carriers are controlled. There is no variation in drive control, high-precision image carrier drive control can be performed, and high-quality images can be obtained.

  In addition, since the drive control of the transfer material transport belt 226 is performed by any one of the drive control devices of the first to fifth embodiments, the accuracy of the drive control of the transfer material transport belt is improved and high accuracy is achieved. As a result, it is possible to perform a driving control of the transfer material conveyance belt and to obtain a high-quality image.

  FIG. 17 is a schematic configuration diagram of an image reading apparatus according to the ninth embodiment of the present invention. This image reading apparatus includes a document table 602 on which a document 901 is placed, a document illumination system 903 that emits light to the document 901, and a photoelectric conversion unit 908 that is a moving body for reading the document. Further, the image reading apparatus includes sub-scanning driving pulleys 909 and 910, a wire 911, a motor 11 as a driving source, and a housing 912. The photoelectric conversion unit 908 includes a CCD (Charge Coupled Device) 905, an imaging lens 906, a total reflection mirror 907, and the like. The photoelectric conversion unit 908 drives the document 901 in the sub-scanning direction using means for fixing the motor 11 to the housing 912 and transmitting a driving force including a wire 911 and pulleys 909 and 910. At this time, the document illumination system 903 including a fluorescent lamp illuminates the document 901 on the document table 902, and the reflected light beam (optical axis is indicated by 904) is folded back by a plurality of mirrors 907, via the imaging lens 906. The image of the original 901 is formed on the light receiving portion of the CCD 905. The photoelectric conversion unit 908 scans the entire surface of the document 901 to read the entire document. In addition, a sensor 913 that indicates a reading start angular displacement is provided at a lower portion of the end portion of the document 901. Further, the photoelectric conversion unit 908 is designed to be in a steady state with a constant rising speed between the home position A and the reading start angular displacement B. After the electric conversion unit 908 reaches the point A, reading is started.

  In the image reading apparatus having the above-described configuration, the driving accuracy of the photoelectric conversion unit 908 that is a moving body greatly affects the quality of the read image, and higher-precision driving control of the photoelectric conversion unit 908 is desired. Therefore, in the image reading apparatus according to the tenth embodiment, in order to drive the photoelectric conversion unit 908 with high accuracy, the drive pulley of the two pulleys 909 and 910 over which the wire 911 for driving the photoelectric conversion unit 908 is stretched. The drive is performed using the rotary drive device shown in FIG. And this rotary body drive device is controlled by the drive control device of any of the first to fifth embodiments.

  Therefore, according to the ninth embodiment, the accuracy of constant speed driving of the photoelectric conversion unit 908 moving along the image surface of the document is improved, and high-quality image reading is possible.

  FIG. 18 shows a tenth embodiment of the present invention. The tenth embodiment is an example of a computer used to execute the rotating body drive control method.

  In FIG. 18, a floppy (R) disk 2003 (recording medium) stores a program for causing the personal computer 2000 to execute the control calculations shown in FIGS. 3, 6, 9, 12, and 13. The personal computer 2000 can execute this control method by executing a program stored in the floppy (R) disk 2003. Specifically, the program includes a control program for driving the rotating body by the computer, a control program for driving the belt conveying device by the computer, and the photosensitive drum driving device of the image forming apparatus by the computer. Control program for controlling a transfer drum driving device of an image forming apparatus by a computer, a control program for controlling a photosensitive belt driving device of the image forming apparatus by a computer, a transfer belt of the image forming apparatus by a computer There are a control program for controlling the driving device, a control program for controlling the transfer material conveying belt driving device of the image forming apparatus by a computer, and the like.

  In addition, this invention is not limited to the said Example. In each of the above embodiments, another object such as a movable optical system of the scanner may be moved in conjunction with the rotating body. The present invention can be applied to image forming apparatuses such as printers and facsimiles other than copying machines, and can also be applied to drive control of machine tools, measuring devices, and the like. The present invention can also be applied to recording media such as hard disks, optical disks, and RAMs other than floppy (R) disks.

  As mentioned above, although the Example of this invention was described, it is not limited to the said Example, A various change is possible in the range which does not deviate from the summary.

  The present invention can also be applied to a photosensitive drum, a transfer drum, a photosensitive belt, an intermediate transfer belt, a paper conveying belt driving device, an image reading device, a machine tool, a measuring device, and the like.

It is a perspective view which shows the external appearance of the pulse motor which concerns on Example 1 of this invention. It is a block diagram which shows the structure of the digital control system which concerns on Example 1 of this invention. It is a block diagram which shows drive control of the rotary body which concerns on Example 1 of this invention. It is a perspective view which shows the external appearance of the pulse motor which concerns on Example 2 of this invention. It is a block diagram which shows the structure of the digital control system which concerns on Example 2 of this invention. It is a block diagram which shows the structure of the digital control system which concerns on Example 2 of this invention. It is a perspective view which shows the external appearance of the pulse motor which concerns on Example 3 of this invention. It is a block diagram which shows the structure of the digital control system which concerns on Example 3 of this invention. It is a block diagram which shows the drive control of the rotary body which concerns on Example 3 of this invention. It is a perspective view which shows the external appearance of the pulse motor which concerns on Example 4 of this invention. It is a block diagram which shows the structure of the digital control system which concerns on Example 4 of this invention. It is a block diagram which shows the drive control of the rotary body which concerns on Example 4 of this invention. It is a block diagram which shows the drive control of the rotary body which concerns on Example 5 of this invention. It is a block diagram which shows the structure of the image forming apparatus which concerns on Example 6 of this invention. It is a block diagram which shows the structure of the image forming apparatus which concerns on Example 7 of this invention. It is a block diagram which shows the structure of the image forming apparatus which concerns on Example 8 of this invention. It is a block diagram which shows the structure of the image reading apparatus which concerns on Example 9 of this invention. It is a perspective view which shows the external appearance of the computer which concerns on Example 10 of this invention.

Explanation of symbols

1 Microcomputer 2 Microprocessor 3 Read only memory (ROM)
4 Random access memory (RAM)
DESCRIPTION OF SYMBOLS 5 Command generator 6 Interface 7 Pulse motor drive device 9 Bus 10 Detection interface device 304,308,310 Operation part 305,401 Control controller part 306,307,309 Block 311 Feedback signal selection part 801 Control object 1501 Pulse motor 1502 Belt 1503 Gear train 1504 Timing belt 1505 Rotating body (drive roller)
1506 Shaft 1507 Encoder 1510, 1511, 1512, 1513, 1514 Driven roller 1516 Coupling 11506 Rotating body 11510 Gear power transmission system, timing belt power transmission system

Claims (24)

A drive control method for a rotating body that controls the driving of the pulse motor so that the rotating body driven using a pulse motor rotates at an equiangular speed,
Detecting angular displacement of the rotating body;
Find the difference between the detected value of the angular displacement and a preset target value of the angular displacement,
A drive pulse frequency of a drive pulse signal used for driving the pulse motor is obtained based on a difference between the two and a standard drive pulse frequency, and it is possible to select whether or not to add the difference between the two to the standard drive pulse. A drive control method for the rotating body.   The difference between the detected value of the angular displacement and a preset target value of the angular displacement is not added to the standard drive pulse when there is an abnormality in the angular displacement detection result of the rotating body. Drive control method for a rotating body. A moving body drive control method for controlling the driving of the pulse motor so that the moving body driven using a pulse motor moves at a constant speed,
Detecting the displacement of the moving body;
Find the difference between the displacement detection value and the preset displacement target value,
In the drive control method for determining the drive pulse frequency of the drive pulse signal used for driving the pulse motor based on the difference between the two and the standard drive pulse frequency, it is possible to select whether or not to add the difference between the two to the standard drive pulse. A drive control method for a moving body.   4. The moving body according to claim 3, wherein when there is an abnormality in the displacement detection result of the moving body, a difference between the detected value of the displacement and a preset target value of the displacement is not added to a standard drive pulse. Drive control method. A drive control device for a rotating body that controls the driving of the pulse motor so that the rotating body driven using a pulse motor rotates at an equiangular speed,
Means for obtaining a difference between a detected value of angular displacement of the rotating body and a preset target value of angular displacement;
Means for determining a drive pulse frequency of a drive pulse signal used for driving the pulse motor based on a difference between the two and a standard drive pulse frequency;
Means for making it possible to select whether or not to add the difference between the two to the standard drive pulse;
A drive control device for a rotating body, comprising:   When there is an abnormality in the angular displacement detection result of the rotating body, the means for selecting whether or not to add the difference between the two to the standard drive pulse is the detected value of the angular displacement and a preset angular displacement target. 6. The drive control device for a rotating body according to claim 5, wherein a difference from the value is selected not to be added to the standard drive pulse. The rotating body is a driving rotating body in which a belt is stretched between a driven rotating body,
7. The drive control apparatus for a rotating body according to claim 5, wherein the driving of the pulse motor is controlled so that the driving rotating body rotates at an equal angular velocity. The rotating body is a driven rotating body in which a belt is stretched between the rotating body for driving,
The drive control apparatus for a rotating body according to claim 5 or 6, wherein the driving of the pulse motor is controlled so that the driven rotating body rotates at an equal angular speed. A driving control device for a moving body that controls the driving of the pulse motor so that the moving body driven using the pulse motor moves at a constant speed,
Means for obtaining a difference between a detected value of displacement of the moving body and a preset target value of displacement;
A means for obtaining a drive pulse frequency of a drive pulse signal used for driving the pulse motor based on a difference between the two and a standard drive pulse frequency; and a means for selecting whether or not to add the difference between the two to the standard drive pulse. A drive control device for a moving body, comprising:   In the means for enabling selection of whether or not to add the difference between the two to the standard drive pulse when there is an abnormality in the displacement detection result of the moving body, the detection value of the displacement and a preset target value of the displacement 10. The drive control apparatus for a moving body according to claim 9, wherein it is selected not to add the difference to the standard drive pulse. The moving body is a belt that is stretched between a driving rotating body and a driven rotating body;
The drive control device for a moving body according to claim 9 or 10, wherein the driving of the pulse motor is controlled so that the belt moves at a constant speed. The displacement detection device of the moving body is a surface sensor attached to the belt surface and having a joint with respect to one circumference of the belt,
The drive control apparatus for a moving body according to claim 11, wherein the displacement detection abnormality of the moving body is the joint.   The drive control apparatus according to any one of claims 5 to 12, wherein an integral element is not present in the means for obtaining the feedback drive pulse frequency. A belt stretched over a plurality of support rotating bodies; a drive control device that controls driving of the belt; and a drive device that drives the belt based on a drive pulse frequency output from the drive control device. A belt device,
As the drive control device, using the drive control device according to any one of claims 5 to 13,
A belt device comprising the angular displacement or means for detecting the displacement. An image carrier, a drive control device that controls driving of the image carrier, and a drive device that drives the image carrier based on a drive pulse frequency output from the drive controller, and the image carrier An image forming apparatus for forming an image by rotating
As the drive control device, using the drive control device according to any one of claims 5 to 14,
An image forming apparatus comprising the angular displacement or means for detecting the displacement.   16. The image forming apparatus according to claim 15, wherein the image carrier is a photosensitive drum.   16. The image forming apparatus according to claim 15, wherein the image carrier is a photosensitive belt.   The image forming apparatus according to claim 16, wherein the image carrier is a transfer drum.   16. The image forming apparatus according to claim 15, wherein the image carrier is an intermediate transfer belt. A plurality of image carriers, a drive control device that controls the drive of each image carrier, and a drive device that drives each image carrier based on a drive pulse frequency output from the drive controller. An image forming apparatus for forming a color image by rotating the image carrier of
As the drive control device, using the drive control device according to claim 5,
An image forming apparatus comprising the angular displacement or means for detecting the displacement. A movable body including an optical system for image reading, a drive control device that controls driving of the movable body, and a drive device that drives the movable body based on a drive pulse frequency output from the drive control device. , An image reading apparatus that reads the image by moving the moving body along the surface of the image reading target,
As the drive control device, using the drive control device according to claim 5,
An image reading apparatus comprising the angular displacement or means for detecting the displacement. A drive control program for realizing, using a computer, drive control for controlling the drive of the pulse motor so that the rotating body driven by the pulse motor rotates at an equiangular speed,
A drive pulse signal used for driving the pulse motor based on a function for obtaining a difference between a detected value of angular displacement of the rotating body and a preset target value of angular displacement, and a difference between the two and a standard drive pulse frequency A computer that realizes a function for obtaining the drive pulse frequency and a function for selecting whether or not to add the difference between the two to the standard drive pulse. A drive control program for realizing, using a computer, drive control for controlling the drive of the pulse motor so that the moving body driven by the pulse motor moves at a constant speed,
Based on a function for obtaining a difference between a detected displacement value of the moving body and a preset target value of displacement, and a drive pulse signal used for driving the pulse motor based on the difference between them and a standard drive pulse frequency A program for causing a computer to realize a function of obtaining a pulse frequency and a function of selecting whether or not to add a difference between the two to a standard drive pulse. A recording medium storing a drive control program,
A recording medium for causing a computer to execute the program according to claim 22 or 23.

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