JP2006113825A - Driving controller, driving control method and image formation apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a driving controller, a driving control method and an image formation apparatus for highly precisely and inexpensively controlling the traveling of a traveling object by transmitting the driving force of a driving means through a plurality of transmitting means. <P>SOLUTION: A copying machine makes a plurality of transmitting means such as an attenuating mechanism, a conveyance roller, a tension roller and electrostatic absorption belt successively transmit the driving force of a driving motor 140 in order to move recording sheets, and detects the positions of the plurality of transmitting means by a rotary encoder 135 and a linear encoder 138, and controls the driving of the driving motor 140 by a position correcting part 404 based on the detected position information. In this case, the rotary encoder 135 and the linear encoder 138 are configured so that the closer to the driving motor 140 the rotary encoder 135 is made, the higher the resolution of the rotary encoder 135 can be made. Therefore, it is possible to inexpensively suppress the piling-up error of the transmitting means, and to inexpensively and highly precisely control the traveling of the traveling object. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a drive control device, a drive control method, and an image forming apparatus. Specifically, the drive force of a drive unit is transmitted via a plurality of transmission units to control movement of a moving object with high accuracy and low cost. The present invention relates to a drive control device, a drive control method, and an image forming apparatus.

  As a precision feeding device that repeats step feeding of an object by rotation of a motor, for example, there is a linear motion precision feeding device composed of a rotary motor, a ball screw, a carriage, a linear motion guide, etc. In order to reduce the stacking error of each mechanism, a highly accurate and high resolution linear scale is attached to the carriage side, and full-closed loop control is performed in which the rotation of the motor is controlled by feeding back the output of the linear scale.

  Further, in recent years, in the field of ink jet recording methods of image forming apparatuses, in order to improve the light resistance and deterioration with time of ink, the ink has changed from a dye system to a pigment system, and the ink viscosity has been increased. It is out. High ink viscosity can drastically reduce the blur on the recording paper, but conversely the poor position displacement accuracy (white streaks, black streaks, banding) of the ink droplets on the recording paper. I came to understand well. In particular, since the contribution ratio of stop position accuracy of recording paper conveyance in the sub-scanning direction is large, increasing the accuracy of the conveyance stop position has become an indispensable technical problem.

  Conventionally, in the sub-scanning direction recording paper conveyance mechanism of the ink jet recording method of the image forming apparatus, a recording paper conveyance method using a grindstone conveyance roller or a conveyance belt is generally used. In general, the feed amount is controlled by installing a code wheel on the conveyance roller shaft and reading the value of the code wheel with an encoder sensor.

  For example, in Patent Document 1, when a recording roller is transported in the sub-scanning direction by disposing a transport roller and a discharge roller on the upstream side and the downstream side of the platen of the image forming apparatus, it is driven via a timing belt. A code wheel is installed on the conveyance roller shaft, and the value of the code wheel is read by an encoder sensor arranged so that the reading direction is perpendicular to the direction of the tension that the conveyance roller receives from the timing belt. A technique for controlling the conveyance of a recording sheet by controlling the rotation accuracy is disclosed.

  Patent Document 2 discloses a technique for reducing a registration deviation due to a variation in the thickness of the conveyor belt by correcting the rotational speed of the motor from the difference in rotational angular speed detected by the rotary encoder.

  Further, Patent Document 3 discloses a technique for correcting the shaft eccentricity by using a magnetic scale as an encoder so that the scale pitch can be changed by a predetermined correction.

JP 2001-248822 A JP 2000-330353 A JP 2001-033275 A

  However, the prior art described above needs to be improved in order to perform position feeding at low cost and with high accuracy.

  In other words, if full-closed loop control is used as a closed-loop control method as described above, a linear scale with higher accuracy and higher resolution than when using semi-closed loop control that feeds back the value of the encoder attached to the rotary motor. Since it needs to be attached, there is a problem that it is expensive and the minimum positioning resolution of the carriage is limited by the resolution of the linear scale.

  Further, in the prior art described in Patent Document 1 to Patent Document 3, it is difficult to perform stop position control with high accuracy due to errors in accumulating parts such as pulleys and transport rollers of the recording paper transport mechanism. There was a problem.

  In view of this, the invention according to claim 1 moves the moving object by sequentially transmitting the driving force of the driving means to the plurality of transmission means, and detects the positions of the plurality of transmission means with a plurality of position detections each having a predetermined resolution. When the driving means is controlled by the control means based on the position information detected by the plurality of position detecting means, the position detecting means closer to the driving means has a higher resolution. It is an object of the present invention to provide a drive control device that suppresses an accumulation error of transmission means at low cost and performs movement control at low cost and with high accuracy.

  According to the second aspect of the present invention, the position information detected by the drive-side position detection means close to the drive means among the plurality of position detection means is corrected based on the position information detected by the driven-side position detection means far from the drive means. Further, by controlling the driving of the driving means based on the corrected position information and the position information detected by the driving side position detecting means, it is possible to suppress the accumulation error of the transmission means at a low cost and detect the driving side position. By using the position information detected by the means with emphasis, the influence of the mechanical resonance due to the inertial moment and the spring constant on the driven side is reduced, the proportional gain can be increased, the control performance is improved, and the movement control is performed. An object of the present invention is to provide a drive control device that is inexpensive and performs with higher accuracy.

  According to a third aspect of the present invention, in the movement region up to a predetermined switching position among the movement regions up to the target movement position of the moving object, the position detection means on the driven side far from the drive means among the plurality of position detection means. In the moving region after the switching position, the detection result of the position detection means on the drive side close to the drive means is selected, and the drive of the drive means is controlled based on the position information of the selection result. Accordingly, an object of the present invention is to provide a drive control device that suppresses the accumulation error of transmission means at low cost, improves control performance with a simple configuration, and performs movement control at a lower cost and with higher accuracy. .

  According to the fourth aspect of the present invention, the speed is calculated based on the position information detected by the position detecting means on the driving side close to the driving means among the plurality of position detecting means, and the driving of the driving means is performed based on the calculated speed information. By controlling the moving speed of the moving object by controlling the speed, it is possible to control the accumulation error of the transmission means at a low cost, move the moving object at high speed, and improve the vibration attenuation, thereby controlling the movement. It is an object of the present invention to provide a drive control device that performs the above operation at a lower cost, with higher accuracy and at higher speed.

  According to the fifth aspect of the present invention, the position detecting means on the driving side close to the driving means among the plurality of position detecting means is a rotation type detecting means, and the position detecting means on the driven side far from the driving means is a direct acting type detecting means. By doing so, it is possible to suppress the accumulation error of the transmission means at low cost and to make the movement control inexpensive and highly accurate, even when the transmission means on the driven side is not a rotating system but a linear motion stage, belt mechanism, etc. An object of the present invention is to provide a drive control device that performs the above operation.

  According to the sixth aspect of the present invention, the position detection means is all the rotation type detection means, and the rotation type detection means that is less expensive than the direct acting type detection means is used, so that the accumulation error of the transmission means can be made even more inexpensively. It is an object of the present invention to provide a drive control device that suppresses the movement and performs movement control at a lower cost and with higher accuracy.

  In the invention according to claim 7, the transmission means is a belt mechanism that is driven by the drive shaft of the drive means to move the moving object, and among the plurality of position detection means, the position detection means on the drive side close to the drive means, By using a rotary type detecting means for detecting the rotational position of the driving shaft of the driving means, and a position detecting means on the driven side far from the driving means as a direct acting type detecting means for detecting the moving position of the belt, the transmission means can be inexpensively transmitted. It is an object of the present invention to provide a drive control device that suppresses an accumulation error of the motor and performs movement control at low cost and with high accuracy.

  According to an eighth aspect of the present invention, the transmission means is a belt mechanism for moving the moving object by moving the belt by the rotation of the rotation drive shaft that is rotationally driven by the drive means, and the drive means among the plurality of position detection means. The position detection means on the drive side close to is a rotation type detection means for detecting the rotation position of the rotation drive shaft that is rotationally driven by the drive means, and the position detection means on the driven side far from the drive means is used to detect the moving position of the belt. By using the direct acting type detecting means, the drive control apparatus that reduces the accumulation error of the transmission means at a low cost, in particular, the accumulation error from the drive means to the rotary drive shaft, and performs the movement control at a lower cost and with higher accuracy. The purpose is to provide.

  According to the ninth aspect of the present invention, the belt that is stretched between the rotation drive shaft and the driven shaft that is rotationally driven by the drive shaft of the drive means is moved by the rotation of the rotation drive shaft. A belt mechanism that moves the object to be moved by the movement, and among the plurality of position detection means, the drive-side position detection means close to the drive means is a rotary detection means that detects the rotational position of the drive shaft of the drive means, By using the position detection means on the driven side far from the drive means as a rotation type detection means for detecting the rotational position of the driven shaft, even when a belt mechanism is provided as the transmission means, the accumulation error of the transmission means can be reduced at a low cost. An object of the present invention is to provide a drive control device that can reduce the movement control at low cost and with high accuracy.

  According to the tenth aspect of the present invention, the belt that is stretched between the rotary drive shaft that is rotationally driven by the drive shaft of the drive means and the driven shaft is moved by the rotation of the rotary drive shaft. The belt mechanism that moves the object to be moved by the movement of the position detection means, and among the plurality of position detection means, the position detection means on the drive side close to the drive means is used to detect the rotation position of the rotary drive shaft that is driven to rotate by the drive means. Even if a belt mechanism is provided as a transmission means, the position detection means on the driven side far from the drive means is a rotation type detection means for detecting the rotational position of the driven shaft, so that transmission is inexpensive. An object of the present invention is to provide a drive control device that reduces the stacking error of the means, in particular, the stacking error from the drive means to the rotary drive shaft, and performs movement control at a low cost and with higher accuracy.

  According to the eleventh aspect of the present invention, the driving force of the driving means is sequentially transmitted by the plurality of transmission means to move the moving object, and the positions of the plurality of transmission means are respectively determined by the plurality of position detection means having a predetermined resolution. When detecting and controlling the driving of the driving means based on the position information detected by the plurality of position detecting means, the position detecting means closer to the driving means has a higher resolution, Among the position detection means, position information detected by the position detection means on the drive side close to the drive means is corrected based on position information detected by the position detection means on the driven side far from the drive means, and the corrected position information and the follower are detected. By controlling the driving of the driving means based on the position information detected by the position detecting means on the side, the accumulation error of the transmitting means can be suppressed at a low cost and detected by the position detecting means on the driving side. By emphasizing the position information, the influence of mechanical resonance due to the inertial moment and spring constant on the driven side is reduced, the proportional gain can be increased, the control performance is improved, the movement control is made cheaper and more An object of the present invention is to provide a drive control method that is performed with higher accuracy.

  According to the twelfth aspect of the present invention, in the movement region up to the predetermined switching position among the movement regions up to the target movement position of the moving object, the position detection means on the driving side close to the driving means among the plurality of position detection means In the moving region after the switching position, the detection result of the position detection means on the driven side far from the drive means is selected, and the drive of the drive means is controlled based on the selected position information. Accordingly, an object of the present invention is to provide a drive control method that suppresses accumulation errors of transmission means at low cost, improves control performance with a simple configuration, and performs movement control at a lower cost and with higher accuracy.

  According to the thirteenth aspect of the present invention, the speed is calculated based on the position information detected by the position detecting means on the driving side close to the driving means among the plurality of position detecting means, and the driving of the driving means is performed based on the calculated speed information. By controlling the moving speed of the moving object by controlling the speed, it is possible to control the accumulation error of the transmission means at a low cost, move the moving object at high speed, and improve the vibration attenuation, thereby controlling the movement. It is an object of the present invention to provide a drive control method that performs the above operation at a lower cost, higher accuracy, and higher speed.

  According to the fourteenth aspect of the present invention, an image forming apparatus that forms an image with the image forming unit in the main scanning direction while moving the recording paper in the sub-scanning direction is used to control the movement of the moving target using the recording paper as the moving target. A drive control device according to any one of claims 1 to 10 is mounted as a drive control device, or a drive control method for controlling movement of the moving object is defined in any one of claims 11 to 13. It is an object of the present invention to provide an image forming apparatus capable of controlling the movement of a recording sheet at a low cost and with high accuracy and improving the image quality at a low cost.

  According to the first aspect of the present invention, the drive control device according to the first aspect of the invention moves the moving object by sequentially transmitting the driving force of the drive means to the plurality of transmission means, and each of the positions of the plurality of transmission means has a plurality of predetermined resolutions. A drive control device that detects by the position detection means and controls the drive of the drive means by the control means based on position information detected by the plurality of position detection means, wherein the plurality of position detection means is the drive means. The above-mentioned object is achieved by having a higher resolution as the position detecting means closer to.

  In this case, for example, as described in claim 2, the drive control device receives position information detected by the position detection unit on the drive side close to the drive unit from among the plurality of position detection units from the drive unit. Correction means for correcting based on position information detected by a distant driven-side position detection means, and the control means includes position information after correction detected by the drive-side position detection means and corrected by the correction means; The driving of the driving unit may be controlled based on position information detected by the driving side position detecting unit.

  Further, for example, the drive control device may detect the plurality of positions in a movement area up to a predetermined switching position among movement areas up to a target movement position of the moving object. The detection result of the position detecting means on the driven side far from the driving means is selected, and the detection result of the position detecting means on the driving side close to the driving means is selected in the movement area after the switching position. Position information selection switching means may be provided, and the control means may control driving of the driving means based on position information selected by the position information selection switching means.

  Further, for example, as described in claim 4, the drive control device calculates a speed based on position information detected by the position detection unit on the drive side close to the drive unit among the plurality of position detection units. Speed calculating means for controlling the moving speed of the moving object by controlling the driving speed of the driving means based on the speed information calculated by the speed calculating means. May be.

  In addition, for example, as described in claim 5, the drive control device is characterized in that the position detection means on the drive side close to the drive means among the plurality of position detection means is a rotary detection means, and the drive The position detecting means on the driven side far from the means may be a direct acting type detecting means.

  Further, for example, as described in claim 6, in the drive control device, all of the position detection means may be rotation type detection means.

  For example, as described in claim 7, in the drive control device, the transmission unit is a belt mechanism that is driven by a drive shaft of the drive unit to move the moving object, and the plurality of position detections are performed. Among the means, the position detection means on the drive side close to the drive means is a rotation type detection means for detecting the rotation position of the drive shaft of the drive means, and the position detection means on the driven side far from the drive means. Further, it may be a direct acting detection means for detecting the moving position of the belt.

  Furthermore, for example, as described in claim 8, in the drive control device, the transmission means moves the moving object by moving a belt by rotation of a rotation drive shaft that is rotationally driven by the drive means. A belt mechanism, and of the plurality of position detection means, the position detection means on the drive side close to the drive means is a rotation type detection means for detecting a rotational position of a rotational drive shaft that is rotationally driven by the drive means; In addition, the position detecting means on the driven side far from the driving means may be a direct acting type detecting means for detecting the moving position of the belt.

  For example, as described in claim 9, the drive control device includes a belt in which the transmission unit is stretched between a rotation drive shaft and a driven shaft that are rotationally driven by a drive shaft of the drive unit. Is moved by the rotation of the rotation drive shaft, and the moving object is moved by the movement of the belt. Among the plurality of position detection means, the position detection means on the drive side close to the drive means A rotation type detection means for detecting the rotation position of the drive shaft of the drive means, and the position detection means on the driven side far from the drive means is a rotation type detection means for detecting the rotation position of the driven shaft. Also good.

  Further, for example, as described in claim 10, the drive control device includes a belt in which the transmission unit is stretched between a rotational drive shaft that is rotationally driven by a drive shaft of the drive unit and a driven shaft. Is moved by the rotation of the rotation drive shaft, and the moving object is moved by the movement of the belt. Among the plurality of position detection means, the position detection means on the drive side close to the drive means Rotation type detection means for detecting the rotation position of the rotation drive shaft that is rotationally driven by the drive means, and the position detection means on the driven side far from the drive means detects the rotation position of the driven shaft. It may be a detection means.

  In the drive control method according to an eleventh aspect of the present invention, the driving force of the driving means is sequentially transmitted by the plurality of transmission means to move the moving object, and the positions of the plurality of transmission means are each set to a plurality of predetermined resolutions. A drive control method for detecting driving by a position detecting means and controlling driving of the driving means based on position information detected by the plurality of position detecting means, wherein the plurality of position detecting means are close to the driving means. The position detection means has higher resolution, and the position information detected by the position detection means on the drive side close to the drive means among the plurality of position detection means is detected by the position detection means on the driven side far from the drive means. And correcting the driving based on the positional information to be corrected, and controlling the driving of the driving means based on the positional information after the correction and the positional information detected by the position detecting means on the driven side. Forms.

  In this case, for example, as described in claim 12, the drive control method includes the plurality of positions in a movement area to a predetermined switching position among movement areas to the target movement position of the moving object. Of the detection means, the detection result of the position detection means on the drive side close to the drive means is selected, and in the movement region after the switching position, the detection result of the position detection means on the driven side far from the drive means is selected. Then, the driving of the driving means may be controlled based on the selected position information.

  Further, for example, as described in claim 13, the drive control method calculates a speed based on position information detected by the position detection unit on the drive side close to the drive unit among the plurality of position detection units. Then, the moving speed of the moving object may be controlled by controlling the driving speed of the driving means based on the calculated speed information.

  An image forming apparatus according to a fourteenth aspect of the present invention is the image forming apparatus in which an image is formed by an image forming unit in the main scanning direction while moving the recording paper in the sub-scanning direction. The drive control device according to any one of claims 1 to 10 is mounted as a drive control device for controlling movement of an object, or as a drive control method for controlling movement of the moving object. The above object is achieved by executing the drive control method according to any one of the above.

  According to the drive control apparatus of the first aspect of the present invention, the driving force of the driving means is sequentially transmitted by the plurality of transmission means to move the moving object, and the positions of the plurality of transmission means each have a predetermined resolution. When detecting the plurality of position detection means and controlling the drive of the drive means by the control means based on the position information detected by the plurality of position detection means, the plurality of position detection means are positioned close to the drive means. Since it has a high resolution, the accumulation error of the transmission means can be suppressed at low cost, and the movement control can be performed at low cost and with high accuracy.

  According to the drive control device of the second aspect of the present invention, position information detected by the drive-side position detection means close to the drive means among the plurality of position detection means is detected by the driven-side position detection means far from the drive means. Since correction is performed based on the position information, and driving of the driving unit is controlled based on the corrected position information and position information detected by the position detection unit on the driving side, the accumulation error of the transmission unit is suppressed at low cost. In addition, the position information detected by the drive-side position detection means is used with emphasis so that the influence of mechanical resonance due to the inertial moment on the driven side and the spring constant can be reduced, and the proportional gain can be increased. Therefore, the control performance can be improved, and the movement control can be performed at low cost and with higher accuracy.

  According to the drive control apparatus of the third aspect of the present invention, in the movement area up to the predetermined switching position among the movement areas up to the target movement position of the moving object, the plurality of position detection means are far from the drive means. Select the detection result of the driven-side position detection means, select the detection result of the drive-side position detection means close to the drive means in the moving area after the switching position, and drive based on the position information of the selection result Since the drive of the means is controlled, the accumulation error of the transmission means can be suppressed at a low cost, the control performance can be improved with a simple configuration, and the movement control is made more inexpensive and more accurate. Can be done.

  According to the drive control apparatus of the fourth aspect of the present invention, the speed is calculated based on the position information detected by the position detecting means on the driving side close to the driving means among the plurality of position detecting means, and the calculated speed information is calculated. Since the movement speed of the moving object is controlled by controlling the driving speed of the driving means based on this, the accumulation error of the transmission means can be suppressed at a low cost, the moving object can be moved at high speed, and Vibration damping can be improved, and movement control can be performed at lower cost, with higher accuracy and at higher speed.

  According to the fifth aspect of the present invention, the drive-side position detection means close to the drive means among the plurality of position detection means is the rotation-type detection means, and the driven-side position detection means far from the drive means. Since it is a direct-acting detection means, it is possible to suppress the accumulation error of the transmitting means at low cost, even when the transmitting means on the driven side is not a rotating system but a linear motion stage, belt mechanism, etc. Control can be performed at low cost and with high accuracy.

  According to the drive control apparatus of the sixth aspect of the present invention, since the position detection means are all rotation type detection means, the use of the rotation type detection means that is less expensive than the direct acting detection means makes it even more inexpensive. Accumulation errors of the transmission means can be suppressed, and movement control can be performed at a lower cost and with higher accuracy.

  According to the drive control device of the seventh aspect of the invention, the transmission means is a belt mechanism that is driven by the drive shaft of the drive means to move the moving object, and among the plurality of position detection means, the drive side close to the drive means This position detection means is a rotation type detection means for detecting the rotational position of the drive shaft of the drive means, and the position detection means on the driven side far from the drive means is a direct acting type detection means for detecting the moving position of the belt. Therefore, the accumulation error of the transmission means can be suppressed at low cost, and the movement control can be performed at low cost and with high accuracy.

  According to the drive control apparatus of the eighth aspect of the invention, the transmission means is a belt mechanism that moves the moving object by moving the belt by the rotation of the rotary drive shaft that is rotationally driven by the drive means, and detects a plurality of positions. Among the means, the position detection means on the drive side close to the drive means is a rotation type detection means for detecting the rotation position of the rotation drive shaft that is rotationally driven by the drive means, and the position detection means on the driven side far from the drive means, Since it is a direct-acting detection means that detects the moving position of the belt, it is possible to reduce the accumulation error of the transmission means, particularly the accumulation error from the drive means to the rotary drive shaft at low cost, and the movement control is inexpensive and This can be performed with higher accuracy.

  According to the drive control device of the ninth aspect of the present invention, the transmission means is configured to rotate the belt stretched between the rotation drive shaft driven by the drive shaft of the drive means and the driven shaft. The belt mechanism moves the object to be moved by the movement of the belt, and among the plurality of position detection means, the position detection means on the drive side close to the drive means detects the rotational position of the drive shaft of the drive means. Since the rotation-type detection means and the driven position detection means far from the drive means are rotation-type detection means for detecting the rotation position of the driven shaft, even if a belt mechanism is provided as the transmission means, transmission is inexpensive. The stacking error of the means can be reduced, and the movement control can be performed at low cost and with high accuracy.

  According to the drive control apparatus of the tenth aspect of the present invention, the transmission means is configured such that the belt stretched between the rotation drive shaft driven by the drive shaft of the drive means and the driven shaft is rotated by the rotation drive shaft. Of the plurality of position detection means, and the position detection means on the drive side close to the drive means is rotated by the drive means. In the case of providing a belt mechanism as a transmission means because it is a rotation type detection means for detecting the rotation position, and the position detection means on the driven side far from the drive means is a rotation type detection means for detecting the rotation position of the driven shaft. In addition, the accumulation error of the transmission means, particularly the accumulation error from the drive means to the rotary drive shaft can be reduced at low cost, and the movement control can be performed at low cost and with higher accuracy.

  According to the drive control method of the invention described in claim 11, the moving object is moved by sequentially transmitting the driving force of the driving means to the plurality of transmitting means, and the positions of the plurality of transmitting means each have a predetermined resolution. When controlling the driving of the driving means based on the position information detected by the plurality of position detecting means and detected by the plurality of position detecting means, the position detecting means closer to the driving means has a higher resolution. The position information detected by the drive-side position detection means close to the drive means is corrected based on the position information detected by the driven-side position detection means far from the drive means, and the correction is performed. Since the drive of the drive means is controlled based on the subsequent position information and the position information detected by the driven position detection means, the accumulation error of the transmission means can be suppressed at a low cost and the drive By using the position information detected by the position detection means with emphasis, the influence of the mechanical resonance due to the inertial moment on the driven side and the spring constant can be reduced, and the proportional gain can be increased to improve the control performance. Therefore, the movement control can be performed at low cost and with higher accuracy.

  According to the drive control method of the twelfth aspect of the present invention, in the movement area up to the predetermined switching position among the movement areas up to the target movement position of the moving object, the drive means is close to the drive means among the plurality of position detection means. The detection result of the position detection means on the driving side is selected, and in the movement region after the switching position, the detection result of the position detection means on the driven side far from the driving means is selected, and the driving means based on the selected position information Because it controls the driving of the vehicle, it is possible to suppress the accumulation error of the transmission means at a low cost, improve the control performance with a simple configuration, and perform the movement control more inexpensively and with higher accuracy. Can do.

  According to the drive control method of the thirteenth aspect of the present invention, the speed is calculated based on the position information detected by the position detection means on the drive side close to the drive means among the plurality of position detection means, and the calculated speed information is calculated. Based on the control of the driving speed of the driving means based on this, the moving speed of the moving object is controlled, so that the accumulation error of the transmitting means can be suppressed at a low cost, and the moving object can be moved at high speed and vibration can be generated. Therefore, the movement control can be performed at a lower cost, with a higher accuracy and at a higher speed.

  According to the image forming apparatus of the fourteenth aspect of the present invention, an image forming apparatus that forms an image with the image forming means in the main scanning direction while moving the recording paper in the sub-scanning direction, the recording paper as the moving object, and the movement A drive control device according to any one of claims 1 to 10 is mounted as a drive control device for controlling movement of an object, or a drive control method for controlling movement of the moving object. Since the drive control method described in any one of 13 is executed, the movement control of the recording paper can be performed with low cost and high accuracy, and the image quality can be improved at low cost.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, since the Example described below is a suitable Example of this invention, various technically preferable restrictions are attached | subjected, However, The scope of the present invention limits this invention especially in the following description. As long as there is no description of the effect, it is not restricted to these aspects.

  1 to 7 are diagrams showing a first embodiment of a drive control device, a drive control method, and an image forming apparatus according to the present invention, and FIG. 1 shows a drive control device, a drive control method, and an image forming apparatus according to the present invention. 1 is a schematic front view of a copying apparatus 1 as an image forming apparatus to which the first embodiment is applied.

  In FIG. 1, the copying apparatus 1 has a scanner unit 200 mounted on the upper part of the ink jet printer unit 100, and is characterized by the conveyance of the recording paper of the ink jet printer unit 100.

  The ink jet printer unit 100 is provided with a paper feed unit 101, a printing unit 102, and a paper discharge unit 103 from below, and the paper feed unit 101 is a paper feed cassette that stores a plurality of cut recording papers 104. The recording paper 104 is sent out one by one by the paper feed roller 106 from 105, and conveyed to the printing unit 102 by the conveyance roller 107. A manual feed tray 108 is provided on the side surface of the print unit 102 of the inkjet printer unit 100, and the recording paper 104 set on the manual feed tray 108 is sent to the print unit 102 by a paper feed roller 109.

  The printing unit 102 includes an inkjet engine 110, a plurality of transport rollers 111, a paper discharge roller 112, an ink cartridge 113, and the like. The paper feeding unit 101 and the printing unit 102 include recording paper as indicated by a dashed line in FIG. A conveyance path 114 is formed.

  The inkjet engine 110 includes a recording paper transport mechanism (drive control device) 115 disposed on the recording paper transport path 114 and a carriage 116 disposed in a state of facing the recording paper transport mechanism 115. The carriage 116 has a print head 117 mounted thereon. The ink jet engine 110 conveys the recording paper in the sub-scanning direction on the recording paper conveyance path 114 by an electrostatic adsorption belt method in which the recording paper conveyance mechanism unit 115 can stably feed the paper as compared with the roller conveyance method, and performs printing. The carriage 116 on which the head 117 is mounted reciprocates in the main scanning direction with respect to the conveyed recording paper 104, and the print head 117 discharges ink droplets, thereby forming an image on the recording paper 104.

  The print head 117 has a four-head configuration of one head for each color of cyan (C), magenta (M), yellow (Y), and black (Bk), and the ink cartridge 113 mounted separately from the print head 117. Ink is supplied to the head of each color of the print head 117 through a supply tube (not shown). In this embodiment, the print head 117 has a four-head configuration with one head for each color, but the number of heads is not limited in any way. For example, one head for two colors is used. A two-head configuration or the like may be used. Further, in this embodiment, a system in which the ink cartridges 113 for each color are mounted separately from the print head 117 is adopted, but this is a large-capacity type ink corresponding to an increase in ink consumption accompanying an increase in printing speed. This is because the cartridge 113 can be used and is suitable for large capacity use, but the print head and the cartridge may be integrated.

  The recording paper transport mechanism 115 is configured as shown in FIG. 2, and an electrostatic suction belt 118 for transporting the recording paper 104 as a moving object in the sub-scanning direction is formed in an endless loop shape. A belt 118 is stretched around a conveying roller (rotary drive shaft) 119 and a tension roller (driven shaft) 120. Around the electrostatic attraction belt 118, there are a charging roller 121 for applying an electric charge to the electrostatic attraction belt 118, a static elimination brush 122 for neutralizing the electrostatic attraction belt 118, and a cleaning blade for cleaning the electrostatic attraction belt 118. 123 are disposed in pressure contact with the outer peripheral surface of the electrostatic attraction belt 118, and the charging roller 121, the charge eliminating brush 122, and the cleaning blade 123 are supported by the bracket 124. The bracket 124 includes a collection unit that stores paper dust, ink stains, and the like removed from the electrostatic attraction belt 118 by the cleaning blade 123.

  A pressure roller 125 is disposed on the conveyance roller 119 so as to face the electrostatic attraction belt 118. The pressure roller 125 is supported by the pressure plate 126. A tip pressure roller 127 is attached to the tip of the pressure plate 126, and the tip pressure roller 127 is against the platen 128 (see FIG. 3) disposed inside the upper side of the electrostatic attraction belt 118. The electrostatic chucking belt 118 is pressed.

  An entrance guide member 129 is arranged on the side of the transport roller 119 on the front side in the transport direction of the recording paper 104. The entrance guide member 129 transports the recording paper 104 fed from the paper feeding unit 101. Guide between the roller 119 (electrostatic chucking belt 118) and the pressure plate 126. The recording paper 104 guided to the upper surface of the electrostatic attraction belt 118 by the entrance guide member 129 is electrostatically attracted to the electrostatic attraction belt 118 and is rotated by the electrostatic attraction belt 118 rotating counterclockwise in FIG. 1 and 2 are conveyed from the right direction to the left direction, that is, in the sub-scanning direction.

  On the downstream side of the tension roller 120 in the conveyance direction of the recording paper 104, a paper discharge roller pair including a paper discharge roller 130 and a spur 131 is provided. Further, the tension roller 120 is provided with a separation claw 132, which is separated from the recording paper 104 from the electrostatic adsorption belt 118, and is disposed between the discharge roller 130 and the spur 131 of the discharge roller pair. send.

  A high-resolution code wheel 133 having slits 133a is mounted on the shaft of the transport roller 119, and a transmissive encoder for detecting the slit 133a of the code wheel 133 is provided in the vicinity of the code wheel 133. A sensor 134 is provided. The code wheel 133 and the encoder sensor 134 constitute a rotary encoder (position detection means, rotation type detection means) 135. It is preferable to use a rotary encoder 135 of 300 LPI or more and 4800 CR or more.

  As shown in FIG. 4, a linear scale 136 is formed on the back surface (inner surface) of the electrostatic adsorption belt 118, and the linear scale 136 is formed by, for example, aluminum vapor deposition (aluminum vapor deposition on the back surface of the electrostatic adsorption belt 118. To form a striped pattern by flying with a laser. The linear scale 136 is not limited to the one using aluminum vapor deposition, and may be manufactured using a photomask or the like, for example. The linear scale 136 is provided at a predetermined position that is not obstructed by the platen 128 disposed on the back surface of the electrostatic attraction belt 118.

  A reflective encoder sensor 137 for reading the linear scale 136 is disposed in the loop of the electrostatic adsorption belt 118. The linear scale 136 and the encoder sensor 137 formed on the back surface of the electrostatic adsorption belt 118 are The linear encoder (position detecting means, direct acting type detecting means) 138 is configured. As the linear encoder 138, it is preferable to use a linear encoder having a resolution of 150 LPI or more in this embodiment.

  Note that the resolutions of the rotary encoder 135 and the linear encoder 138 differ depending on the required positioning accuracy of the copying apparatus 1, in particular, the inkjet printer unit 100. In this embodiment, the linear scale 136 is formed on the back side of the electrostatic attraction belt 118. However, the position of the electrostatic attraction belt 118 such as the surface of the electrostatic attraction belt 118 or the end face of the electrostatic attraction belt 118 is set. Any position can be used as long as it can be measured appropriately.

  Then, as shown in FIG. 4, the recording paper transport mechanism 115 is driven by a drive motor (drive means) 140 via a speed reduction mechanism 139 so that the electrostatic attraction belt 118 is illustrated. 1 to 4, the recording sheet 104 is rotated and driven counterclockwise, and the recording sheet 104 is attracted and conveyed. The conveyance position of the conveyed recording sheet 104, that is, the conveyance of the electrostatic adsorption belt 118. The position is detected by detecting the linear scale 136 formed on the back surface (inner surface) of the electrostatic attraction belt 118 with the encoder sensor 137. In addition, the recording paper conveyance mechanism unit 115 rotates the code wheel 133 attached to the rotation shaft of the conveyance roller 119 that is stretched around the electrostatic adsorption belt 118 and rotated by the drive motor 140 via the attenuation mechanism 139. By detecting the slit 133 a formed in the code wheel 133 with the encoder sensor 134, the transport position of the code wheel 133, that is, the electrostatic adsorption belt 118 that is the rotational position of the transport roller 119 is detected. That is, the attenuating mechanism 139, the transport roller 119, the tension roller 120, and the electrostatic attraction belt 118 as a whole transmit a driving force of the driving motor 140 as a driving unit in order to move the object 104 by moving along the moving object. It functions as a transmission means.

  Note that, as described above, the copying apparatus 1 according to the present embodiment is provided with the linear scale 136 on the back surface of the electrostatic attraction belt 118 for detecting the position of the driven side, and the linear encoder 138 for detecting the linear scale 136 is statically installed. Although it is disposed inside the electroadhesive belt 118, the detection configuration on the driven side is not limited to such a configuration. For example, on the axis of the tension roller 120 that is the driven shaft of the electrostatic adsorption belt 118 In addition, a high-resolution code wheel having slits similar to those on the drive side may be attached, and a rotary encoder provided with a transmissive encoder sensor for detecting the slits of the code wheel may be used. Also in this case, the resolution of the driven rotary encoder is assumed to be lower than the resolution of the driving rotary encoder 135.

  Further, the copying apparatus 1 of this embodiment is attached to the rotation shaft of the transport roller 119 that is close to the drive motor 140, that is, as a drive-side position detection means, and is driven to rotate by the drive motor 140 via the damping mechanism 139. Although the rotary encoder 135 detects the slit 133a formed in the code wheel 133 by the encoder sensor 134, the detection position is not limited to the rotational drive shaft of the transport roller 119. For example, the code wheel 133 may be attached to the drive shaft of the drive motor 140, and the slit 133 a of the code wheel 133 attached to the drive shaft of the drive motor 140 may be detected by the encoder sensor 134. In this case, the position detection means on the driven side may be a rotary encoder configured by a code wheel and an encoder sensor attached to the rotation shaft of the transport roller 119. The drive-side position detection means is a rotary encoder composed of a code wheel and an encoder sensor attached to the drive shaft of the drive motor 140 or the rotation drive shaft of the transport roller 119, and the driven-side position detection means is the driven shaft. It is good also as a rotary encoder comprised with the code wheel and encoder sensor attached to the rotating shaft of the tension roller 120 which is.

  In FIG. 1 again, the printing unit 102 conveys the recording sheet 104 printed by the inkjet engine 110 to the sheet discharge roller 112 on the recording sheet conveyance path 114 by the plurality of conveyance rollers 111, and the sheet discharge roller. The sheet is discharged onto the sheet discharge unit 103 by 112.

  In the scanner unit 200, a scanning mechanism 202 is disposed below the contact glass 201 so that the scanning mechanism 202 can travel in the sub-scanning direction, and a document set on the contact glass 201 is irradiated with light emitted from the light source 203 of the scanning mechanism. Reflected light from the original is introduced into the CCD 206 via the mirror 204 and the lens 205, and the original image is read. A pressure plate 207 is provided above the contact glass 201 so as to be openable and closable.

  The copying apparatus 1 has a circuit block configuration as shown in FIG. 5, and includes a DSP (Digital Signal Processor) 301, a host I / F (HOST I / F) 302, a ROM (Read Only Memory) 303, a RAM ( Random Access Memory (304), a counter 305, the rotary encoder 135 and linear encoder 138, a DAC (voltage-current converter) 306, a motor driver 307, and the like. The main components are connected by a bus 308.

  That is, the copying apparatus 1 of the present embodiment uses a DSP (control means) 301 as a main part of the drive control device, but the drive control device is not limited to the one using the DSP 301. For example, A dedicated circuit such as a CPU (Central Processing Unit), an analog circuit, or an ASIC (Application Specific Integrated Circuit) may be used.

  The DSP 301 is a DSP dedicated to control computation, and exchanges information such as target position information and drive mode with the host via the host I / F 302. As the host I / F 302, a serial interface, a parallel interface, a shared memory, a predetermined register, or the like is used. The DSP 301 performs a control calculation based on a calculation program in the ROM 303 and stores data at the time of calculation in the RAM 304. The DSP 301 may load a program in the ROM 303 into the RAM 304 at the time of initialization and execute it on the RAM 304 in order to speed up the control calculation.

  The copying apparatus 1 includes two encoders 135 and 138 as incremental rotary encoders 135 and linear encoders 138. When encoders 135 and 138 output A-phase and B-phase pulses, the encoders 135 and 138, respectively. Are counted by a counter 305 having a counter for two systems. Generally, the value obtained by multiplying the A-phase B-phase pulse by 4 is counted, and the up / down is determined from the phase difference between the A-phase and the B-phase. The DSP 301 reads the position information from the counter 305 and sets a value corresponding to the command current value in the DAC 306 based on the results of predetermined correction calculation and control calculation. The DAC 306 supplies a voltage corresponding to the current value to the motor driver 307, and the motor driver 307 drives the drive motor 140 based on the command voltage. In this embodiment, the motor driver 307 is a current control driver and the current control is performed by the motor driver 307. However, the motor driver 307 is not limited to the current control driver. The motor drive current may be fed back to the DSP 301 via an ADC (current-voltage converter) (not shown) and current control may be performed by the DSP 301, or a motor driver that can directly set a voltage value from the DSP 301. Good. Also, the drive method of the motor driver 307 is generally the PWM (Pulse Wide mosulation) method, but when performing precise position control, a linear drive motor driver is used. May be.

  In addition, when detecting the speed from the encoder pulses from the rotary encoder 135 and the linear encoder 138, a method of calculating a difference by the DSP 301, a method using an F / V (frequency / voltage) conversion circuit, or a pulse interval using a basic clock. It is possible to use a method using a speed counter for measuring.

  Next, the operation of this embodiment will be described. In the copying apparatus 1 of this embodiment, the recording paper 104 sent from the paper supply unit 101 to the printing unit 102 is conveyed in the sub scanning direction by the recording paper conveyance mechanism unit 115 of the printing unit 102 and the carriage 116 is subjected to main scanning. Printing is performed by ejecting ink droplets from the print head 117 mounted on the carriage 116 by moving in the direction.

  In order to improve the printing quality of the copying apparatus 1, the recording paper 104 needs to be conveyed with high accuracy. Therefore, in the copying apparatus 1 of the present embodiment, the encoder that detects the transfer position of the transfer sheet 104 is used as the recording sheet transfer mechanism 115 and the rotary encoder 135 that is closer to the drive motor 140 that transfers the transfer sheet 104 (drive side). Two (a plurality) of linear encoders 138 farther from the drive motor 140 (driven side), and the resolution of the rotary encoder 135 on the drive side is set higher than the resolution of the linear encoder 138 on the driven side. By controlling the drive of the drive motor 140 based on the detection results of the two encoders 135, the conveyance position of the recording paper 104 is controlled with high accuracy, and the print quality is improved at low cost.

  That is, the drive-side rotary encoder 135 detects the slit 133a of the code wheel 133 attached to the rotation shaft of the transport roller 119 that is rotationally driven by the drive motor 140 via the damping mechanism 139, and the driven-side linear encoder 138. Is formed on the back surface (inner surface) of the electrostatic attraction belt 118 that is bridged between the conveyance roller 119 and the tension roller 120 and rotates while the conveyance roller 119 rotates to adsorb the recording paper 104. The linear scale 136 is detected. The resolution of the drive-side rotary encoder 135 is set to be higher than the resolution of the driven-side linear encoder 138, and the copying apparatus 1 outputs the detection output of the drive-side rotary encoder 135 to the driven-side linear encoder. Correction is performed with the detection output of 138, drive control of the drive motor 140 is performed, and the transport position of the recording paper 104 is controlled with high accuracy to improve the print quality.

  The copying apparatus 1 includes a drive control function unit 400 having only a feedback loop shown as a functional block diagram in FIG. 6 for controlling the transport position of the recording paper 104 in a circuit using the DSP 301 in FIG. Constructed by executed software and controlling the driving of the driving motor 140, the conveyance position control of the recording paper 104 is performed with high accuracy.

  The drive control mechanism unit 400 includes a comparator 401, a position compensator 402, a motor driver 307, a drive motor 140, a drive-side rotary encoder 135, a control target unit 403, a driven-side linear encoder 138, a position correction unit 404, and the like. Is done.

  The DSP 301 performs a control calculation of the position compensator 402 by a periodic timer interruption. The control operation of the position compensator 402 is PID (proportional integral derivative), classical control theory such as phase advance and phase lag, state feedback based on modern control theory that feeds back the state quantity of the control target unit 403, or Any compensation method such as a robust control theory represented by H∞ control is used.

  The DSP 301 uses a discretized state equation as shown in the following formula (1) or a z-transformed transfer function as this calculation method, and uses the discretized state equation of the formula (1) and the following formula for each periodic interrupt. The control calculation is performed using the discretized output equation (2).

[X (n + 1)] = P · x (n) + Q · u (n) (1)
y (n) = C · x (n) + D · u (n) (2)
These equations (1) and (2) represent one input u (n) and one output y (n), and the vector [x (n)] is a state variable, matrix P, Q, C, D Are constants of the discretized state equation and the discretized output equation. By changing the constants that are the matrices P, Q, C, and D, the gain of the position compensator 402 is changed, and the characteristics of the position compensator 402 are changed.

  Further, the DSP 301 performs the calculation as the position correction unit 404 at the same timer interrupt calculation timing and processing time other than the timer interrupt as in the case of the position compensator 402, and the calculation method will be described later.

  Then, the drive control function unit 400 receives the target value (target position) and the position information fed back from the position correction unit 404 as input to the comparator 401. The comparator 401 receives the target value and the position information. Are output to the position compensator 402 as a position deviation. The position compensator 402 multiplies the position deviation input from the comparator 401 by a predetermined gain and a predetermined filter process, and outputs the result to the motor driver 307 as a voltage command value or a current command value.

  The motor driver 307 can use a voltage control driver that passes a motor voltage according to a voltage command value or a current control driver that flows a motor current according to a current command value. In the following description, a current having a simple transfer characteristic is used. A description will be given assuming that a control driver is used. The motor driver 307 drives the drive motor 140 based on the motor current corresponding to the command current from the position compensator 402.

  The rotary encoder 135 detects the rotational position (driving position) of the transport roller 119 corresponding to the motor shaft of the driving motor 140 or the rotational position of the driving shaft, and outputs it to the position correction unit 404 as position information. The electrostatic attraction belt 118, which is the control target unit 403 that conveys the recording paper 104, is driven by the driving force, and the position (driven position) of the electrostatic attraction belt 118 is detected by the linear encoder 138 to obtain position information as position information. The data is output to the correction unit 404.

  The position correction unit 404 corrects the position information detected by the rotary encoder 135 based on the position information of the linear encoder 138 for the movement region to the predetermined switching position in the vicinity of the positioning target position, and the corrected position information is compared with the comparator. Feedback to 401. Further, after the predetermined switching position, the position correction unit 404 feeds back the position information of the rotary encoder 135 that is not corrected by the linear encoder 138 directly to the comparator 401.

  As the drive motor 140, a DC brush motor, a DC brushless motor, an AC servo motor, or the like can be used. Depending on the type of servo motor, the drive type of the motor driver 307 (single phase, three phase, Hall element input, etc.) ) Will also change.

  As the correction operation of the position correction unit 404, for example, the movement amount of the electrostatic attraction belt 118 corresponding to one pulse of the encoder output of the driven linear encoder 138 having the lower resolution in the two encoders 135 and 138. L1 is the amount of movement of the electrostatic attraction belt 118 corresponding to one pulse of the encoder output of the rotary encoder 135 on the driving side, which has the higher resolution, L2, and the correlation coefficient which is the ratio of L1 and L2 is a (a = L1 / L2), the number of pulses of the high-resolution encoder (rotary encoder 135) corresponding to a predetermined amount of movement of the electrostatic chucking belt 118 is N, and the electrostatic chucking belt 118 is set to a low-resolution encoder (linear encoder 138). Pulse number n1 and high-resolution encoder (rotary encoder 135) pulse number n2 (where n2 is 0) When moving by a predetermined movement amount in an integer) of less than a, corrects the pulse number N of the rotary encoder 135 of the high resolution equation (3).

N = a · n1 + n2 (3)
In this way, by correcting the detection result of the high-resolution drive-side rotary encoder 135 with the detection result of the low-resolution driven-side linear encoder 138, the damping mechanism 139, the drive motor 140, and the conveyance roller 119, which are transmission mechanisms, are corrected. In this case, the accumulation error of the transmission mechanism such as the shaft diameter variation and temperature change of the drive shaft is suppressed, and the resolution shortage of the linear encoder 138 on the driven side is corrected, so that the position of the electrostatic attraction belt 118 and the recording paper 104 can be accurately detected. Can be detected and controlled. Therefore, the printing quality of the copying apparatus 1 can be improved.

  In the above description, the servo motor is used as the drive motor 140. However, the drive motor is not limited to the servo motor, and, for example, a stepping motor may be used.

  When a stepping motor is used as the drive motor, a drive control function unit 410 as shown in FIG. 7 is constructed by a circuit using the DSP 301 of FIG. The drive control function unit 410 includes a pulse calculation unit 411, a pulse generation unit 412, a motor driver 307a, a stepping motor drive motor 140a, a drive-side rotary encoder 135, a control target unit 403, a driven-side linear encoder 138, and a position. It comprises a correction unit 404 and the like.

  The pulse calculation unit 411 receives the number of pulses corresponding to the target position (target pulse) and the number of pulses corresponding to the fed back position information from the position correction unit 404. The pulse calculation unit 411 receives the target pulse and the position information pulse. And the necessary number of feed pulses is output to the pulse generator 412. The pulse generator 412 outputs a drive pulse to the motor driver 307a at a cycle corresponding to the target speed, and the motor driver 307a drives the drive motor 140a based on the nest.

  Similarly to the above, the rotary encoder 135 detects the rotation position (drive position) of the transport roller 119 corresponding to the motor shaft of the drive motor 140a or the rotation position of the drive shaft, and outputs it to the position correction unit 404. The electrostatic attraction belt 118 that is the control target unit 403 that conveys the recording paper 104 is driven by the driving force of the motor 140, and the position (driven position) of the electrostatic attraction belt 118 is detected by the linear encoder 138. The data is output to the correction unit 404.

  The position correction unit 404 corrects the position information detected by the rotary encoder 135 to the vicinity of the positioning target position based on the position information of the linear encoder 138, and feeds back the corrected position information to the comparator 401. Further, the position correction unit 404 feeds back the position information of the rotary encoder 135 that is not corrected by the linear encoder 138 directly to the comparator 401 after the vicinity of the predetermined target position.

  As described above, even when the stepping motor drive motor 140a is used as the drive motor, the same can be applied.

  As described above, the copying apparatus 1 according to the present exemplary embodiment sequentially transmits the driving force of the driving motor 140 through the damping mechanism 139, the plurality of transmission units including the conveying roller 119, the tension roller 120, and the electrostatic attraction belt 118. The recording paper 104 is moved, and the positions of the plurality of transmission means are detected by the rotary encoder 135 and the linear encoder 138, which are a plurality of position detection means each having a predetermined resolution, and the rotary encoder 135 and the linear encoder are detected. When the DSP 301 controls the drive motor 140 based on the position information detected by 138, the rotary encoder 135 and the linear encoder 138 have higher resolution as the rotary encoder 135 closer to the drive motor 140.

  Therefore, it is possible to suppress an accumulation error of the damping mechanism 139, the conveying roller 119, the tension roller 120, the electrostatic adsorption belt 118, and the like that are transmission means at low cost, and the movement control can be performed at low cost and with high accuracy.

  Further, the copying apparatus 1 according to the present embodiment detects position information detected by the drive-side rotary encoder 135 close to the drive motor 140 out of the rotary encoder 135 and the linear encoder 138 by the driven-side linear encoder 138 far from the drive motor 140. The drive motor 140 is driven based on the corrected position information and the position information detected by the rotary encoder 135 on the drive side.

  Therefore, it is possible to suppress the accumulation error of the damping mechanism 139, the conveying roller 119, the tension roller 120, the electrostatic attraction belt 118, and the like as transmission means at low cost, and attach importance to the position information detected by the rotary encoder 135 on the driving side. As a result, it is possible to improve the control performance by reducing the influence of mechanical resonance due to the inertial moment and the spring constant on the driven side, and increasing the proportional gain, making the movement control cheaper and more It can be performed with high accuracy.

  FIG. 8 is a functional block configuration diagram of the drive control mechanism 500 of the copying apparatus to which the second embodiment of the drive control apparatus, drive control method, and image forming apparatus of the present invention is applied.

  The present embodiment is applied to a copying apparatus similar to the copying apparatus 1 of the first embodiment. In the description of this embodiment, the same components as those of the copying apparatus 1 of the first embodiment are described. The same reference numerals are used to omit detailed description thereof, and portions not shown in the drawings will be described using the same reference numerals used in the description of the first embodiment as necessary.

  In FIG. 8, a drive control mechanism unit 500 having only a feedback loop shown as a functional block diagram is constructed by software executed by a circuit using the DSP 301 shown in FIG. By performing the drive control, the transport position control of the recording paper 104 is performed with high accuracy.

  The drive control mechanism 500 includes a comparator 401, a position compensator 402, a motor driver 307, a drive motor 140, a drive-side rotary encoder 135, a control target unit 403, a driven-side linear encoder 138, a position information switching unit 501, The switching control unit 502 and the conversion coefficient unit 503 are included.

  The DSP 301 performs a control calculation of the position compensator 402 by periodic timer interruption, as in the case of the first embodiment.

  In addition, the DSP 301 performs the calculation as the switching control unit 502 that performs the switching control of the position information switching unit 501 at the same timer interruption calculation timing as the case of the position compensator 402 and the processing time other than the timer interruption. The calculation method will be described later. The position information switching unit 501 and the switching control unit 502 function as position information selection means.

  The comparator 401 receives the target value (target position) and the position information fed back from the position correction unit 404, and the comparator 401 compares the target value with the position information to obtain a position deviation as a position compensator. Output to 402. The position compensator 402 multiplies the position deviation input from the comparator 401 by a predetermined gain and a predetermined filter process, and outputs the result to the motor driver 307 as a voltage command value or a current command value.

  The motor driver 307 can use a voltage control driver that passes a motor voltage according to a voltage command value or a current control driver that flows a motor current according to a current command value. In the following description, a current having a simple transfer characteristic is used. A description will be given assuming that a control driver is used. The motor driver 307 drives the drive motor 140 based on the motor current corresponding to the command current from the position compensator 402.

  As the drive motor 140, a DC brush motor, a DC brushless motor, an AC servo motor, or the like can be used. Depending on the type of servo motor, the drive type of the motor driver 307 (single phase, three phase, Hall element input, etc.) ) Will also change.

  The rotary encoder 135 detects the rotation position (drive position) of the rotation drive shaft of the transport roller 119 corresponding to the drive shaft of the drive motor 140 or the rotation position of the drive shaft, and sends it to the position information switching unit 501 and the switching control unit 502. The electrostatic attraction belt 118 that is the control target unit 403 that conveys the recording paper 104 is driven by the driving force of the drive motor 140 and the linear encoder 138 sets the position (driven position) of the electrostatic attraction belt 118. It is detected and output to the conversion coefficient unit 503 and the switching control unit 502.

  The conversion coefficient unit 503 converts the position information from the linear encoder 138 into a value corresponding to the position information output from the rotary encoder 135 and outputs the value to the position information switching unit 501.

  The switching control unit 502 receives the position information from the rotary encoder 135 and the position information from the linear encoder 138 and the target value, and the switching control unit 502 receives the actual position from the rotary encoder 135. And the position information from the linear encoder 138 and the target value (target position information) are compared, and the driven position is determined until the actual position reaches a predetermined switching position set before the target position. The switching of the position information switching unit 501 is controlled so as to select the position information from the detected linear encoder 138, and the driving position is detected when the actual position is after the predetermined switching position. The switching of the position information switching unit 501 is controlled so as to select the position information from the drive-side rotary encoder 135.

  The position information switching unit 501 is controlled by the switching control unit 502 to detect the position information from the rotary encoder 135 and a value corresponding to the position information detected by the linear encoder 138 and output from the rotary encoder 135 by the conversion coefficient unit 503. Is selectively selected, and the selected position information is fed back to the comparator 401. The switching of the position information from the rotary encoder 135 by the position information switching unit 501 and the position information by the linear encoder 138 means that one of the two systems of position information is selected in terms of software executed by the DSP 301. is doing.

  The predetermined position serving as a switching point of the position information switching unit 501 is at least larger than the resolution of the driven linear encoder 138 having a lower resolution than the rotary encoder 135 on the driving side. In this embodiment, the case where two types of position information of the drive-side rotary encoder 135 and the driven-side linear encoder 138 are input has been described. However, only the position information of one of the encoders may be used.

  In this way, with a simple configuration, the transmission mechanism build-up error such as the damping mechanism 139, the drive motor 140, and the conveying roller 119, the shaft diameter variation of the drive shaft, the temperature change, and the like are suppressed, and the driven side The lack of resolution of the linear encoder 138 is corrected, and the position of the electrostatic attraction belt 118 and the recording paper 104 can be detected and controlled with high accuracy. Therefore, the printing quality of the copying apparatus 1 can be improved.

  In the above description, the servo motor is used as the drive motor 140. However, the drive motor is not limited to the servo motor, and, for example, a stepping motor may be used. In this case, it can be executed with a circuit configuration similar to that in FIG. 7, and by using the position information switching unit 501, the switching control unit 502, and the conversion coefficient unit 503 in FIG. 8 instead of the position control unit 404 in FIG. 7. Can respond.

  As described above, the copying apparatus 1 according to the present embodiment has the rotary encoder 135 and the linear encoder 138 in the movement area up to the predetermined switching position among the movement areas up to the target movement position of the recording paper 104 that is the moving object. The detection result of the driven linear encoder 138 far from the drive motor 140 is selected, and in the movement region after the switching position, the detection result of the rotary encoder 135 on the drive side close to the drive motor 140 is selected. The drive of the drive motor 140 is controlled based on the resulting position information.

  Accordingly, it is possible to suppress the stacking error of the damping mechanism 139, the conveyance roller 119, the tension roller 120, the electrostatic adsorption belt 118, and the like at a low cost, and it is possible to improve the control performance with a simple configuration and to further control the movement. It can be performed at a lower cost and with higher accuracy.

  FIG. 9 is a functional block configuration diagram of a drive control mechanism unit 600 of a copying apparatus to which a third embodiment of the drive control apparatus, drive control method, and image forming apparatus of the present invention is applied.

  The present embodiment is applied to a copying apparatus similar to the copying apparatus 1 of the first embodiment. In the description of this embodiment, the same components as those of the copying apparatus 1 of the first embodiment are described. The same reference numerals are used to omit detailed description thereof, and portions not shown in the drawings will be described using the same reference numerals used in the description of the first embodiment as necessary.

  In FIG. 9, a drive control mechanism unit 600 having only a position and velocity feedback loop shown as a functional block diagram is constructed and driven by software executed by a circuit using the DSP 301 shown in FIG. By controlling the drive of the motor 140, the transport position control of the recording paper 104 is performed with high accuracy.

  The drive control mechanism unit 600 includes a comparator 401, a phase compensator 402, a comparator 601, a speed compensator 602, a motor driver 307, a drive motor 140, a drive-side rotary encoder 135, a control target unit 403, and a driven-side linear. It includes an encoder 138, a position correction unit 404, a speed calculation unit 603, and the like. Note that the speed calculation unit 603 may be configured by hardware that measures the pulse interval using a basic clock.

  As in the case of the first embodiment, the DSP 301 performs control calculations for the position compensator 402 and the speed compensator 602 by periodic timer interruption.

  When adding velocity information feedback inside position information feedback, as shown in FIG. 9, it is generally necessary to increase the velocity information feedback response frequency relative to the position information feedback response frequency. Therefore, it is necessary to increase the calculation sampling frequency of the DSP 301. Therefore, timer interrupts can be dealt with by preparing dedicated positions for the position compensator 402 and the speed compensator 602, or by providing dedicated DSPs 301 for the position compensator 402 and the speed compensator 602, respectively.

  The speed calculation unit (speed calculation means) 603 is constructed by software executed by the DSP 301, calculates a speed by taking a difference in position information for each timer interrupt and dividing by the time interval of the timer interrupt cycle.

  The comparator 401 receives the target value (target position) and the position information fed back from the position correction unit 404, and the comparator 401 compares the target value with the position information to obtain a position deviation as a position compensator. Output to 402. The position compensator 402 multiplies the position deviation input from the comparator 401 by a predetermined gain or a predetermined filter process, and outputs a target speed to the comparator 601. The comparator 601 outputs the target speed and the speed. The speed information fed back from the calculation unit 603 is compared and output to the speed compensator (speed control means) 602 as a speed deviation.

  The speed compensator 602 multiplies the speed deviation input from the comparator 601 by a predetermined gain or a predetermined filter process and outputs the result to the motor driver 307 as a voltage command value or a current command value. Note that the position compensator 402 and the speed compensator 602 are, as described above, the PID, classical control theory such as phase advance and phase lag, state feedback based on the modern control theory that feeds back the state quantity of the control target unit 403, or Any compensation method such as a robust control theory represented by H∞ control may be used.

  The motor driver 307 can use a voltage control driver that passes a motor voltage according to a voltage command value or a current control driver that flows a motor current according to a current command value. In the following description, a current having a simple transfer characteristic is used. A description will be given assuming that a control driver is used. The motor driver 307 drives the drive motor 140 based on the motor current corresponding to the command current from the speed compensator 602.

  As the drive motor 140, a DC brush motor, a DC brushless motor, an AC servo motor, or the like can be used. Depending on the type of servo motor, the drive type of the motor driver 307 (single phase, three phase, Hall element input, etc.) ) Will also change.

  The rotary encoder 135 detects the rotation position (drive position) of the conveying roller 119 corresponding to the motor shaft of the drive motor 140 or the rotation position of the drive shaft, and outputs it as position information to the position correction unit 404 and the speed calculation unit 603. The electrostatic attraction belt 118 that is the control target unit 403 that conveys the recording paper 104 is driven by the driving force of the driving motor 140, and the position (driven position) of the electrostatic attraction belt 118 is detected by the linear encoder 138. The position correction unit 404 outputs the position information.

  The position correction unit 404 corrects the position information detected by the rotary encoder 135 to the vicinity of the positioning target position based on the position information of the linear encoder 138, and feeds back the corrected position information to the comparator 401. Further, the position correction unit 404 feeds back the position information of the rotary encoder 135 that is not corrected by the linear encoder 138 directly to the comparator 401 after the vicinity of the predetermined target position.

  Then, the speed calculation unit 603 uses the method (F (frequency) / V (voltage) conversion, etc.) for measuring the position information difference and the position information period for each predetermined period to input position information from the rotary encoder 135. Is converted into speed information, and the converted speed information is fed back to the comparator 601.

  In this way, with a simple configuration, the transmission mechanism build-up error such as the damping mechanism 139, the drive motor 140, and the conveying roller 119, the shaft diameter variation of the drive shaft, the temperature change, and the like are suppressed, and the driven side The lack of resolution of the linear encoder 138 is corrected, and the position of the electrostatic attraction belt 118 and the recording paper 104 can be detected and controlled with high accuracy. Therefore, the printing quality of the copying apparatus 1 can be improved.

  In the above description, the servo motor is used as the drive motor 140. However, the drive motor is not limited to the servo motor, and, for example, a stepping motor may be used. In this case, it can be executed with a circuit configuration similar to that in FIG. 7, and by using the position information switching unit 501, the switching control unit 502, and the conversion coefficient unit 503 in FIG. 8 instead of the position control unit 404 in FIG. 7. Can respond.

  As described above, the copying apparatus 1 according to the present embodiment calculates the speed based on the position information detected by the drive-side rotary encoder 135 close to the drive motor 140 out of the rotary encoder 135 and the linear encoder 138, and the calculated speed. Based on the information, the driving speed of the driving motor 140 is controlled to control the moving speed of the recording paper 104 as the moving object.

  Accordingly, it is possible to suppress the stacking error of the damping mechanism 139, the conveyance roller 119, the tension roller 120, the electrostatic adsorption belt 118, and the like at a low cost, and to move the recording paper 104, which is a moving object, at high speed and to vibrate. Therefore, the movement control can be performed at a lower cost, with a higher accuracy and at a higher speed.

  FIG. 10 is a schematic configuration diagram of a linear stage 700 to which the fourth embodiment of the drive control apparatus, the drive control method, and the image forming apparatus of the present invention is applied.

  The linear stage 700 includes a linear guide (not shown), a ball screw 701, a carriage 702 that moves in one direction while being restrained by the linear guide, a drive motor 703 that drives the ball screw 701, a motor shaft encoder 704, and the like. A linear encoder 705 for detecting the position of the carriage 702 is provided.

  The linear stage 700 according to the present embodiment includes a motor drive circuit, a drive control circuit, and the like, and these include a motor driver and a drive control mechanism unit similar to those in the first to third embodiments. However, since these are the same as those in the first to third embodiments, illustration and description thereof are omitted.

  Here, the motor shaft encoder 704 closer to the drive motor 703 (drive side) has a higher resolution than the resolution of the linear encoder 705 farther from the drive motor 703 (driven side).

  With this configuration, by performing drive control similar to the drive control in each of the above embodiments, the position control of the carriage 702 can be performed at a low cost and with high accuracy in the linear stage 700 as well.

  The invention made by the present inventor has been specifically described based on the preferred embodiments. However, the present invention is not limited to the above, and various modifications can be made without departing from the scope of the invention. Needless to say.

  In addition to image forming apparatuses such as printers and copiers that record while transporting recording paper of an inkjet method, etc., recording paper transport drive control device of the image forming apparatus, and recording paper transport drive control method, as well as precision feeding device that repeats step feed Etc. can be applied.

1 is a schematic front view of a copying apparatus 1 to which a first embodiment of a drive control apparatus, a drive control method, and an image forming apparatus of the present invention are applied. FIG. 2 is an enlarged front view of a recording paper transport mechanism unit in FIG. 1. FIG. 3 is an enlarged front view of a main part of the recording paper transport mechanism unit in FIG. 2. FIG. 3 is an enlarged perspective view of a main part of the recording paper transport mechanism unit in FIG. 2. FIG. 2 is a configuration diagram of a main circuit block of the copying apparatus in FIG. 1. FIG. 3 is a functional block configuration diagram of recording paper conveyance position control of a copying apparatus. FIG. 7 is a functional block configuration diagram of recording paper transport position control when a stepping motor is used as the drive motor of FIG. 6. FIG. 9 is a functional block configuration diagram of recording paper transport position control of a copying apparatus to which a second embodiment of the drive control apparatus, drive control method, and image forming apparatus of the present invention is applied. FIG. 9 is a functional block configuration diagram of recording paper transport position control of a copying apparatus to which a third embodiment of the drive control apparatus, drive control method, and image forming apparatus of the present invention is applied. FIG. 10 is a schematic configuration diagram of a linear stage to which a fourth embodiment of the drive control device, the drive control method, and the image forming apparatus of the present invention is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Copier 100 Inkjet printer part 101 Paper feed part 102 Printing part 103 Paper discharge part 104 Recording paper 105 Paper feed cassette 106 Paper feed roller 107 Conveyance roller 108 Manual feed tray 109 Paper feed roller 110 Inkjet engine 111 Conveyance roller 112 Paper discharge roller 113 Ink cartridge 114 Recording paper conveyance path 115 Recording paper conveyance mechanism 116 Carriage 117 Print head 118 Electrostatic adsorption belt 119 Conveyance roller 120 Tension roller 121 Charging roller 122 Static elimination brush 123 Cleaning blade 124 Bracket 125 Pressure roller 126 Pressure plate 127 Tip addition Pressure roller 128 Platen 129 Entrance guide member 130 Paper discharge roller 131 Spur 132 Separation claw 133 Code wheel 133a Slit 134 Encoder sensor 135 Rotary encoder 136 Linear scale 137 Encoder sensor 138 Linear encoder 200 Scanner unit 201 Contact glass 202 Scanning mechanism 203 Light source 204 Mirror 205 Lens 206 CCD
207 Pressure plate 301 DSP
302 Host I / F (HOST I / F)
303 ROM
304 RAM
305 Counter 306 DAC
307 Motor driver 308 Bus 400 Drive control mechanism unit 401 Comparator 402 Position compensator 403 Control target unit 404 Position correction unit 401 Comparator 402 Position compensator 500 Drive control mechanism unit 501 Position information switching unit 502 Switching control unit 503 Conversion coefficient unit 600 Drive control mechanism 601 Comparator 602 Speed compensator 701 Ball screw 702 Carriage 703 Drive motor 704 Motor shaft encoder 705 Linear encoder

Claims (14)

  The driving force of the driving means is sequentially transmitted by a plurality of transmitting means to move the moving object, and the positions of the plurality of transmitting means are detected by a plurality of position detecting means each having a predetermined resolution, and the plurality of positions are detected. A drive control device that controls the drive of the drive unit by a control unit based on position information detected by the detection unit, wherein the plurality of position detection units have higher resolution as the position detection unit is closer to the drive unit. The drive control apparatus characterized by the above-mentioned.   The drive control device is configured to detect position information detected by the position detection means on the drive side close to the drive means among the plurality of position detection means based on position information detected by the position detection means on the driven side far from the drive means. The control means is based on the corrected position information detected by the drive-side position detection means and corrected by the correction means and the position information detected by the drive-side position detection means. 2. The drive control apparatus according to claim 1, wherein the drive of the drive means is controlled.   The drive control device is configured such that, in a movement region up to a predetermined switching position among movement regions up to a target movement position of the moving object, the position on the driven side far from the driving unit among the plurality of position detection units. A detection result of the detection means is selected, and in a moving region after the switching position, a position information selection switching means for selecting a detection result of the position detection means on the driving side close to the driving means is provided, and the control means includes: 2. The drive control apparatus according to claim 1, wherein the drive means is controlled based on position information selected by the position information selection switching means.   The drive control device includes: a speed calculation unit that calculates a speed based on position information detected by the position detection unit on the drive side close to the drive unit among the plurality of position detection units; and the speed calculation unit calculates 4. The apparatus according to claim 1, further comprising: a speed control unit that controls a moving speed of the moving object by controlling a driving speed of the driving unit based on speed information. The drive control apparatus described.   In the drive control device, of the plurality of position detection means, the position detection means on the drive side close to the drive means is a rotation type detection means, and the position detection means on the driven side far from the drive means is linearly moved. 5. The drive control apparatus according to claim 1, wherein the drive control apparatus is a mold detection unit.   5. The drive control apparatus according to claim 1, wherein all of the position detection means are rotation-type detection means.   In the drive control device, the transmission unit is a belt mechanism that is driven by a drive shaft of the drive unit to move the moving object, and among the plurality of position detection units, the drive side closer to the drive unit The position detection means is a rotation type detection means for detecting the rotational position of the drive shaft of the drive means, and the position detection means on the driven side far from the drive means detects the moving position of the belt. 6. The drive control apparatus according to claim 5, wherein the drive control apparatus is a means.   The drive control device is a belt mechanism in which the transmission means moves the moving object by moving a belt by rotation of a rotational drive shaft that is rotationally driven by the drive means, and among the plurality of position detection means The position detection means on the drive side close to the drive means is a rotation type detection means for detecting the rotation position of the rotation drive shaft that is rotationally driven by the drive means, and the position detection on the driven side far from the drive means. 6. The drive control apparatus according to claim 5, wherein the means is a direct acting detection means for detecting a moving position of the belt.   In the drive control device, the transmission means moves a belt stretched between a rotation drive shaft and a driven shaft, which are rotationally driven by the drive shaft of the drive means, by the rotation of the rotation drive shaft. The movement mechanism moves the moving object, and among the plurality of position detection means, the position detection means on the drive side close to the drive means detects the rotational position of the drive shaft of the drive means. 7. The drive control apparatus according to claim 6, wherein the position detection means on the driven side far from the drive means is a rotation type detection means for detecting a rotation position of the driven shaft.   In the drive control device, the transmission means moves a belt stretched between a rotation drive shaft and a driven shaft, which are rotationally driven by the drive shaft of the drive means, by the rotation of the rotation drive shaft. Of the plurality of position detection means, and the position detection means on the drive side close to the drive means is a rotary drive shaft that is rotationally driven by the drive means. 7. The rotation type detection means for detecting a rotation position, wherein the position detection means on the driven side far from the drive means is a rotation type detection means for detecting the rotation position of the driven shaft. Drive control device.   The driving force of the driving means is sequentially transmitted by a plurality of transmitting means to move the moving object, and the positions of the plurality of transmitting means are detected by a plurality of position detecting means each having a predetermined resolution, and the plurality of positions are detected. A driving control method for controlling driving of the driving unit based on position information detected by the detecting unit, wherein the plurality of position detecting units have higher resolution as the position detecting unit is closer to the driving unit. Position information detected by the position detection means on the driving side close to the driving means is corrected based on position information detected by the position detection means on the driven side far from the driving means, and after the correction A drive control method for controlling the drive of the drive means based on the position information of and the position information detected by the position detection means on the driven side.   The drive control method is configured such that, in a movement region up to a predetermined switching position among movement regions up to a target movement position of the moving object, the position on the driving side close to the driving unit among the plurality of position detection units. The detection result of the detection means is selected, and in the movement region after the switching position, the detection result of the position detection means on the driven side far from the drive means is selected, and the drive means is selected based on the selected position information. The drive control method according to claim 11, wherein the drive is controlled.   The drive control method calculates a speed based on position information detected by the position detection means on the drive side close to the drive means among the plurality of position detection means, and the drive means based on the calculated speed information The driving control method according to claim 11, wherein the moving speed of the moving object is controlled by controlling the driving speed of the moving object. In the image forming apparatus that performs an image with the image forming unit in the main scanning direction while moving the recording paper in the sub-scanning direction, the drive sheet is a moving target object, and the drive control apparatus is configured to control movement of the moving target object. The drive control method according to any one of claims 11 to 13 is executed as a drive control method in which the drive control device according to any one of claims 1 to 10 is mounted or the movement object is controlled to move. An image forming apparatus.

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