JP2007171513A - Driving apparatus for use in image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent unevenness of the rotating speed of the output shaft of a reduction gear caused by the elastic deformation of a planet roller from affecting an image. <P>SOLUTION: A driving apparatus includes a planet roller type power transmission unit and a drive control part. The planet roller type power transmission unit includes: a plurality of planet rollers 4 that are brought in press contact with the outer peripheral surface of the rotating shaft of the motor, and partly constituted of an elastic body; a ring 6 whose inner peripheral surface comes in contact with the plurality of planet rollers 4, and having a protrusion 6a protruding over the outer peripheral surface thereof; a fixing body 9 positioned so as to cover the ring 6a, and having an opening 9a formed in a position corresponding to the protrusion 6a of the ring 6, having a width so that the protrusion 6a can move as long as a prescribed distance; a carrier roller 7 that rotates cooperatively with the rotation of the planet roller 4; and the output shaft that outputs the rotation of the carrier roller 7 to the outside. The rotation of the motor is controlled by the drive control part so that the protrusion 6a of the ring 6 may reciprocate in the opening 9a of the fixing body 9 in a prescribed period after the motor starts. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a driving device used in an image forming apparatus.

  A color image forming apparatus such as a color printer or a color copying machine has a rotation driving device for rotating and driving a photosensitive drum or a transfer belt for each color component. Some rotary drive devices include a motor and a planetary reduction device that reduces the rotation of the motor.

  In recent years, with the reduction in cost of color image forming apparatuses, planetary rollers in planetary reduction devices are being formed at least partially using elastic bodies such as rubber. Since the elastic body of the planetary roller is pressed against the output shaft that transmits the rotation of the motor to the outside, elastic deformation occurs. Elastic deformation generated in the planetary roller of the elastic body causes fluctuations in the rotational speed of the output shaft of the speed reducer. Further, an image generated while the rotational speed of the output shaft of the speed reducer fluctuates, color misregistration, color unevenness, and the like appear.

Patent Document 1 discloses a rotation drive device that makes the rotation speed of an output shaft uniform by directly controlling the rotation speed of a motor when an elastic body is used for a planetary roller. Specifically, the rotation drive device of Patent Document 1 includes a stepping motor, an elastic body speed reduction device, and feedback control means. The elastic body speed reduction device includes a torque transmission unit that transmits torque by frictional contact of an elastic body and does not include a torque transmission unit using gears, and decelerates the rotation of the motor and outputs it to the photosensitive drum. The feedback control means detects the output rotation speed of the elastic body speed reduction device, obtains a difference value from the target speed, gives a speed command signal to the motor based on the difference value, and directly controls the rotation speed of the motor.
JP 2002-1717779 A

  However, the apparatus of Patent Document 1 has the following problems.

  The elastic deformation generated in the planetary roller of the elastic body before the motor stops rotating and restarts causes unevenness in the rotational speed of the output shaft of the reduction gear for a while after the restarting. When the motor is stopped, the period in which the rotational speed of the output shaft of the speed reducer caused by the elastic deformation generated in the planetary roller is not uniform is much longer than the response time when the apparatus of Patent Document 1 performs feedback control. Therefore, if the rotation control of the motor is controlled by detecting the unevenness of the output shaft rotation speed of the speed reducer caused by the elastic deformation generated in the planetary roller when the motor is stopped by the feedback control related to the device of Patent Document 1, over-control occurs. End up.

  Further, the time until the elastic deformation generated in the planetary roller of the elastic body is restored by the rotation of the motor depends on the temperature of the planetary roller. For example, if the planetary roller is at a low temperature, it takes a long time to restore the elastic deformation generated in the planetary roller. The temperature of the planetary roller changes according to the environment where the color image forming apparatus is used.

  Therefore, the present invention provides a drive device that prevents unevenness in rotational speed at the output shaft of the speed reducer caused by elastic deformation of the planetary roller from affecting the image. The present invention provides a drive device that prevents the elastic deformation of the planetary roller from affecting the image regardless of the temperature of the planetary roller of the elastic body.

  In order to solve the above-mentioned problems, the invention 1 provides a drive device including a planetary roller power transmission unit and drive control means. The planetary roller type power transmission unit includes a plurality of planetary rollers, a ring, a fixed body, a carrier roller, and an output shaft. The plurality of planetary rollers are pressed against the outer peripheral surface of the rotating shaft of the motor, and at least a part thereof is formed of an elastic body. The ring is in contact with the plurality of planetary rollers on the inner peripheral surface, and has a protruding portion protruding on the outer peripheral surface. The fixed body is positioned so as to cover the ring, and an opening having a width that allows the protrusion to move a predetermined distance is formed at a position corresponding to the protrusion of the ring. The carrier roller rotates in conjunction with the rotation of the planetary roller. The output shaft outputs the rotation of the carrier roller to the outside. And a drive control means controls rotation of a motor so that the protrusion part of a ring may reciprocate in the opening part of a fixed body during the predetermined time from the time of motor starting.

  Assume that this apparatus is connected to an image forming apparatus. While the motor is stopped, elastic deformation occurs in the portion of the planetary roller formed of the elastic body and in contact with the motor rotation shaft. In this apparatus, the motor is rotated at a slow speed so that the protrusion of the ring reciprocates within the opening of the fixed body for a predetermined time from the start of the motor. When the motor rotates at a slow speed, the planetary roller also rotates at a slow speed. At this time, since there is play in the fixed body, it is possible to suppress the occurrence of wear of the planetary roller on the contact surface between the planetary roller and the ring. Of the elastic body of the planetary roller, the portion that has undergone elastic deformation when the motor is stopped reciprocates on the outer peripheral surface of the motor rotation shaft, so that it is restored to be extended by the motor rotation shaft. Therefore, even when the image forming process is started, the rotation speed of the output shaft in this apparatus is constant. Therefore, it is possible to avoid phenomena such as color misregistration and color unevenness that occur in an image due to non-uniform rotation speed of the output shaft.

  A second aspect of the present invention provides the driving device according to the first aspect, further including a detection unit that detects a temperature of the planetary roller or the vicinity of the planetary roller. The drive control unit of the drive device includes a slow rotation time determination unit that determines a predetermined time based on the temperature detected by the detection unit, and an image forming process after at least the predetermined time has elapsed since the start of the motor. Image processing control means for starting the process.

  The time required for restoring the elastic deformation generated in the elastic part of the planetary roller depends on the temperature of the elastic part of the planetary roller. This apparatus determines a predetermined time for the ring protrusion to reciprocate within the opening of the stationary body in accordance with the temperature of the planetary roller or the vicinity thereof. As a result, even when the time for restoring the elastic deformation differs because the temperatures of the planetary rollers are different, the image forming process is started after the elastic deformation is restored.

  A third aspect of the invention relates to the first or second aspect of the invention in which the planetary roller is a predetermined on the outer peripheral surface of the rotation shaft of the motor centering on a portion where the planetary roller and the outer peripheral surface of the rotation shaft of the motor are in contact with each other when the rotation of the motor is stopped Provided is a drive device in which the drive control means controls the rotation of the motor so as to reciprocate the width of the motor.

  When the rotation of the motor is stopped, elastic deformation occurs in a portion of the elastic body of the planetary roller that is in contact with the rotation shaft of the motor. This apparatus controls the rotation of the motor so that the elastically deformed portion of the planetary roller is in contact with the motor rotation shaft. That is, when the projecting portion of the ring reciprocates within the opening of the fixed body, the planetary roller reciprocates on the outer peripheral surface of the motor rotation shaft with the elastic deformation of the planetary roller as a center. Thereby, the part which elastic deformation produced among the elastic bodies of a planetary roller is restored so that it may extend. Thereby, the part which elastic deformation produced among the elastic bodies of a planetary roller can be decompress | restored reliably.

  According to the present invention, it is possible to prevent unevenness in the rotational speed of the output shaft of the speed reducer caused by elastic deformation of the planetary roller from affecting the image. Further, according to the present invention, it is possible to prevent the elastic deformation of the planetary roller from affecting the image regardless of the temperature of the planetary roller as an elastic body.

<Embodiment>
FIG. 1 is a diagram illustrating a cross-sectional configuration of a driving device according to the present embodiment and a connection with peripheral devices. 1 is connected to an image forming apparatus 11 and is used as an apparatus for driving a photosensitive drum provided in the image forming apparatus 11. The image forming apparatus 11 is a color image forming apparatus used in, for example, a color printer or a color copying machine.

  FIG. 2 is a schematic diagram of the image forming apparatus 11. The image forming apparatus 11 is a so-called tandem type full-color image forming apparatus in which four unfixed visible images of four colors are transferred onto a recording sheet and then fixed, and is a photoconductor disposed along a sheet conveyance path. An image forming unit for each color (Y, M, C, B) including a drum 111 (image carrier) and the like is included. The driving device 1 is provided corresponding to each photosensitive drum 111 so that each photosensitive drum 111 can be driven.

(1) Configuration of Drive Device FIG. 3 is a cross-sectional view taken along line III-III of the drive device 1 of FIG. Below, the structure of the drive device 1 is demonstrated using FIG.1 and FIG.3.

  The driving device 1 according to the first embodiment includes a motor 2, a motor rotation shaft 3, a plurality of planetary rollers 4, a rotation speed sensor 5a, a temperature sensor 5b (corresponding to detection means), a ring 6, a carrier roller 7, an output shaft 8, A fixed body 9 and a drive control unit 10 are included.

  The motor rotation shaft 3 outputs the rotation of the motor 2 to the outside. The plurality of planetary rollers 4 are positioned in a state of being pressed between the outer peripheral surface of the motor rotating shaft 3 and the inner peripheral surface of the ring 6. In this embodiment, the case where there are three planetary rollers 4 is taken as an example. The edge of each planetary roller 4 is formed of an elastic body 4a. Examples of the elastic body 4a include rubber and resin. The rotational speed sensor 5 a is located on the inner peripheral surface of the fixed body 9 and detects the rotational speed of the carrier roller 7. The temperature sensor 5b is provided outside the motor 2 and the fixed body 9 and in the vicinity of the fixed body 9, and detects the temperature Te of the entire planetary roller power transmission unit described later. The ring 6 is positioned so as to surround the three planetary rollers 4 and is in contact with each planetary roller 4 on the inner peripheral surface. Further, the ring 6 has a protruding portion 6a protruding on the outer peripheral surface. The carrier roller 7 is located on the opposite side of the motor 2 when viewed from the planetary roller 4, and is connected to the planetary roller 4 by the rotation shaft 4 b of the planetary roller 4. The carrier roller 7 is connected to the output shaft 8 via a bearing 8 a located at a part of the fixed body 9. The edge of the carrier roller 7 is formed by a magnet 7a. The output shaft 8 outputs the rotation of the carrier roller 7 to the outside on the same axis as the motor rotation shaft 3. The fixed body 9 is located outside the motor 2 and surrounds the motor rotating shaft 3, the three planetary rollers 4, the rotation speed sensor 5 a, the ring 6 and the carrier roller 7. The fixed body 9 is formed with an opening 9 a having a width that allows the protrusion 6 a to move a predetermined distance at a position corresponding to the protrusion 6 a of the ring 6. Hereinafter, the planetary roller 4, the ring 6, the carrier roller 7, the output shaft 8, and the fixed body 9 are collectively referred to as a “planetary roller power transmission unit”.

  The drive control unit 10 is located outside the motor 2 and the fixed body 9, and is connected to the motor 2, the temperature sensor 5 b, and the image forming apparatus 11. The configuration of the drive control unit 10 will be described later.

(2) Operations of Planetary Roller Type Power Transmission Unit and Motor Rotation Shaft Next, operations of the planetary roller type power transmission unit and the motor rotation shaft 3 will be described with reference to FIG.

  First, the motor rotation shaft 3 rotates in the rotation direction of the motor 2. Then, the three planetary rollers 4 revolve in the same direction as the rotation direction of the motor rotation shaft 3 along the inner peripheral surface of the ring 6 around the motor rotation shaft 3. Furthermore, each planetary roller 4 rotates about the rotation axis of each planetary roller 4 in the direction opposite to the rotation direction of the motor rotation shaft 3. The carrier roller 7 rotates in conjunction with the revolution of the planetary roller 4. That is, the carrier roller 7 rotates in the same direction as the rotation direction of the motor rotation shaft 3. At this time, the carrier roller 7 rotates at a speed at which the rotation of the motor rotating shaft 3 is decelerated by the rotation of the planetary roller 4.

  The ring 6 rotates in conjunction with the revolution of the planetary roller 4. That is, the ring 6 rotates about the motor rotation shaft 3 in the same direction as the revolution direction of the planetary roller 4, but has the protrusion 6 a, so that the protrusion 6 a passes through the opening 9 a of the fixed body 9. Rotate as much as you can move. For example, when the motor rotating shaft 3 and the ring 6 rotate clockwise and the protrusion 6a of the ring 6 contacts the inner wall of the opening 9a of the fixed body 9, the ring 6 stops rotating. In this state, when the motor rotating shaft 3 starts to rotate in the reverse direction, the protruding portion 6a of the ring 6 is separated from the inner wall of the opening 9a in contact, and the ring 6 rotates in the same direction as the motor rotating shaft 3. And if the protrusion part 6a contact | connects the inner wall on the opposite side to the opening part 9a of the fixing body 9, the ring 6 will stop rotation. That is, the protrusion 6 a of the ring 6 reciprocates within the opening 9 a of the fixed body 9 by changing the rotation direction of the motor rotation shaft 3.

(3) Configuration of Drive Control Unit Next, a functional configuration of the drive control unit 10 according to the present embodiment will be described. FIG. 4 is a diagram illustrating a functional configuration of the drive control unit 10 according to the present embodiment. The drive control unit 10 includes a timer 101, a slow rotation time determination unit 102, a motor drive control unit 103, a motor rotation direction control unit 104, and a motor rotation speed control unit 105.

(3-1) Timer The timer 101 outputs time information. The time information of the timer 101 is used when the motor drive control unit 103, the motor rotation direction control unit 104, and the motor rotation speed control unit 105 generate signals.

(3-2) Slow Rotation Time Determining Unit The slow rotation time determining unit 102 is based on the temperature Te of the entire planetary roller power transmission unit including the temperature of the elastic body 4a in the planetary roller 4 detected by the temperature sensor 5b. The reciprocation period Ts in which the six protrusions 6a reciprocate within the opening 9a of the fixed body 9 is determined.

  Further, when receiving an image formation instruction signal indicating an instruction to start an image formation process from the outside, the drive control unit 10 acquires the temperature Te of the entire planetary roller power transmission unit from the temperature sensor 5b. Then, the slow rotation time determination unit 102 of the drive control unit 10 determines the reciprocation period Ts in which the protrusion 6a of the ring 6 reciprocates the opening 9a of the fixed body 9 based on the acquired temperature Te, and controls the motor rotation direction. The reciprocation period Ts is notified to the unit 104 and the motor rotation speed control unit 105. Note that the order in which the slow speed rotation time determination unit 102 determines the reciprocation period Ts based on the temperature Te and the timing in which the motor drive control unit 103 drives the motor 2 are not particularly limited. Whichever is first.

  Hereinafter, an example in which the slow rotation time determination unit 102 determines the reciprocation period Ts will be briefly described. Assume that the drive control unit 10 includes a storage unit (not shown). The storage unit stores a round trip time table for determining the round trip period Ts of the protrusion 6 a of the ring 6. FIG. 5 is a round trip period table stored in the storage unit. The round trip period table of FIG. 5 stores the temperature range and the conditional expression of the round trip period Ts as one record. The conditional expression of the reciprocating period Ts is a condition for determining the reciprocating period Ts so as to be equal to or longer than the time required for restoring the elastic deformation generated in the elastic body 4a of the planetary roller 4 when the motor is stopped. For example, the temperature range “0 ≦ Te <20” and the condition “Ts = 10 + (20−Te) /2.89” for determining the round trip time Ts are stored in association with each other. Here, “2.89” is a value associated with the type of fixing material used in a fixing device (not shown in FIGS. 1 and 3). The conditional expression for the reciprocation period Ts may be set based on the elastic modulus of the elastic body 4a in the planetary roller 4 and the like. This is because the elastic modulus of the elastic body 4a changes depending on the type of substance.

  Then, the slow rotation time determination unit 102 determines which of a plurality of temperature ranges in the round trip period table stored in the storage unit the temperature Te detected by the temperature sensor 5b corresponds to. Then, the slow rotation time determination unit 102 determines the reciprocation period Ts corresponding to the temperature range corresponding to the temperature Te. The slow rotation time determination unit 102 passes the determined reciprocation period Ts to the motor rotation direction control unit 104, the motor rotation speed control unit 105, and the image processing control unit 106.

(3-3) Motor Drive Control Unit The motor drive control unit 103 performs drive control of the motor 2. For example, the motor drive control unit 103 generates a motor drive control signal MOT_DR for controlling on / off of the drive of the motor 2 based on the time information from the timer 101, and outputs it to the motor 2.

(3-4) Motor Rotation Direction Control Unit The motor rotation direction control unit 104 generates a motor rotation direction control signal MOT_DIR for instructing the rotation direction of the motor and outputs it to the motor 2. Specifically, when the motor rotation direction control unit 104 receives the reciprocation period Ts from the slow speed rotation time determination unit 102, the motor rotation direction control unit 104 generates an image formation instruction signal indicating an image formation start instruction based on the time information from the timer 101. The measurement of the round-trip period Ts is started from the time when received from. The motor rotation direction control unit 104 is configured such that the ring protrusion 6a is the opening of the fixed body 9 from the time when the image formation instruction signal indicating the image formation start instruction is received from the outside until the reciprocation period Ts elapses. The motor rotation direction control signal MOT_DIR is output to the motor 2 every predetermined time so as to reciprocate within the 9a.

  Further, after the reciprocation period Ts elapses, the motor rotation direction control unit 104 generates a motor rotation direction control signal MOT_FCLK for rotating the motor 2 in the forward direction and outputs it to the motor 2.

(3-5) Motor Rotation Speed Control Unit The motor rotation speed control unit 105 generates a motor rotation speed control signal MOT_FCLK for instructing the rotation speed of the motor 2 and outputs it to the motor 2. Specifically, when the motor rotation speed control unit 105 acquires the reciprocation period Ts from the slow rotation time determination unit 102, the motor rotation speed control unit 105 generates an image formation instruction signal indicating an image formation start instruction from the outside based on time information from the timer 101. The measurement of the round trip period Ts is started from the time of reception. The motor rotation speed control unit 105 is configured such that the protruding portion 6a of the ring 6 is the opening 9a of the fixed body 9 from the time when the image formation instruction signal indicating the image formation start instruction is received from the outside until the reciprocation period Ts elapses. The motor rotation speed control signal MOT_FCLK is output to the motor 2 and the image processing control unit 106 every predetermined time so as to move at a very low speed.

  In addition, after the reciprocation period Ts has elapsed, the motor rotation speed control unit 105 generates a motor rotation speed control signal MOT_FCLK for the motor 2 to perform steady rotation, and outputs the motor rotation speed control signal MOT_FCLK to the motor 2 and the image processing control unit 106.

(3-6) Image Processing Control Unit The image processing control unit 106 generates an image processing control signal for controlling execution and termination of the image forming processing in the image forming apparatus 11 based on the time information from the timer 101. The image is transmitted to the image forming apparatus 11. Specifically, the image processing control unit 106 monitors a motor rotation speed control signal MOT_FCLK. Then, the image processing control unit 106 controls the image forming apparatus 11 to start the image forming process after the motor rotation speed control signal MOT_FCLK of the motor rotation speed control unit 105 becomes constant. Here, the image forming processing includes image forming correction processing such as color registration processing and calibration processing.

(4) Operation of Each Function in Drive Control Unit FIG. 6 is a timing chart showing the operation of the drive control unit 10. The image formation instruction signal is a signal for instructing start and end of execution of image formation processing. Note that the image processing control signal in FIG. 6 represents the execution of the image forming process as “1” and the end as “0”. The motor drive control signal MOT_DR represents “0” for motor stop and “1” for drive. The motor rotation direction control signal MOT_DIR represents “1” as the clockwise direction of the motor drive shaft 3 and “0” as the counterclockwise direction of the motor drive shaft 3 in FIG.

  First, when receiving an image formation instruction signal indicating an instruction to start image formation processing from the outside, the drive control unit 10 switches the motor drive control signal MOT_DR from “0” to “1” and outputs it to the motor 2. Here, “external” of the drive control unit 10 is, for example, the image forming apparatus 11.

  The motor rotation direction control unit 104 outputs a motor rotation direction control signal MOT_DIR to the motor 2 when the motor drive control signal MOT_DR rises and the reciprocation period Ts is acquired from the slow speed rotation time determination unit 102. Specifically, the motor rotation direction control unit 104 periodically outputs pulses having a predetermined cycle and a predetermined high period. The motor rotation direction control unit 104 repeats this for the reciprocation period Ts determined by the slow rotation time determination unit 102. Here, the number of pulses output periodically depends on the width of the opening 9a formed in the fixed body 9 and the rotational speed of the motor 2 while the protrusion 6a of the ring 6 reciprocates in the opening 9a. It is determined. In the present embodiment, for example, the opening 9a has a width of about 30 degrees in terms of the rotation angle of the motor rotating shaft 3, and the rotation speed of the motor 2 is “0.2” while the protrusion 6a reciprocates in the opening 9a. In the case of “rpm”, the pulse cycle is “90.9 msec” and the number of pulses is “200”.

  The motor rotation speed control unit 105 outputs a motor rotation speed control signal MOT_FCLK to the motor 2 when the motor drive control signal MOT_DR rises and the reciprocation period Ts is acquired from the slow speed rotation time determination unit 102. Specifically, the motor rotation speed control unit 105 has a pulse having a predetermined cycle and a predetermined high period during the reciprocation period Ts determined by the slow rotation time determination unit 101 and indicating a constant rotation speed. Are output periodically. In the present embodiment, for example, when the motor 2 is rotated at a speed of “0.2 rpm”, the cycle of the motor rotation speed control signal MOT_FCLK is set to “90.9 msec”, and the high period of the motor rotation speed control signal MOT_FCLK is set to “2 msec”. (Duty: 2.2%).

  As described above, during the reciprocation period Ts, the motor 2 rotates slightly in the clockwise direction and the counterclockwise direction based on the signals sent from the motor rotation direction control unit 104 and the motor rotation speed control unit 105. . Then, the protrusion 6a of the ring 6 reciprocates in the opening 9a of the fixed body 9, and the planetary roller 4 has a portion where the planetary roller 4 and the outer peripheral surface of the motor rotating shaft 3 are in contact with each other when the motor 2 stops rotating. A predetermined width on the outer peripheral surface of the motor rotating shaft 3 is reciprocated as the center. As a result, the portion of the elastic body 4a of the planetary roller 4 where the elastic deformation 4a occurs when the rotation of the motor 2 is stopped is restored to be stretched.

  When the reciprocation period Ts elapses, the motor rotation direction control unit 104 and the motor rotation speed control unit 105 output a signal for rotating the motor 2 in one direction at a steady speed faster than during the reciprocation period Ts. To do. Accordingly, the motor 2 rotates at the rotation direction and speed based on the motor rotation direction control signal MOT_DIR and the motor rotation speed control signal MOT_FCLK, and reaches a steady rotation state.

  The image processing control unit 106 transmits the image processing control signal “0” to the image forming apparatus 11 while the motor rotation speed control signal MOT_FCLK including the reciprocation period Ts is not constant. After the motor rotation speed control signal MOT_FCLK is constant, that is, after the motor 2 is in a steady rotation state, the image processing control unit 106 transmits an image processing control signal “1” to the image forming apparatus 11. Then, the image forming apparatus 11 receives the image processing control signal “1” and executes the image forming process.

(5) Effect According to the drive device 1 according to the present embodiment, the portion of the elastic body 4a of the planetary roller 4 that has undergone elastic deformation when the motor 2 is stopped is rotated during a predetermined time from the start of the motor 2. In order to reciprocate the outer peripheral surface of the shaft 3, the shaft 3 is restored to be extended by the motor rotating shaft 3. For this reason, even when the image forming apparatus 11 starts the image forming process, the rotation speed of the output shaft 8 of the driving apparatus 1 is constant, so that the color shift generated in the image due to the nonuniform rotation speed of the output shaft 8. And phenomena such as color unevenness can be avoided. When the portion of the elastic body 4a of the planetary roller 4 that has undergone elastic deformation when the motor 2 is stopped reciprocates on the outer peripheral surface of the motor rotating shaft 3, there is play in the fixed body 9a. Generation of wear of the planetary roller 4 on the contact surface can be suppressed.

  In the driving device 1, the protrusion 6 a of the ring 6 reciprocates in the opening 9 a of the fixed body 9 according to the temperature Te of the entire planetary roller power transmission unit including the temperature of the elastic body 4 a in the planetary roller 4. A predetermined time is determined. Thereby, even if the elastic body 4a temperature of the planetary roller 4 is different and the time for restoring the elastic deformation is different, the driving device 1 starts the image forming process of the image forming apparatus 11 after the elastic deformation is restored. Can be made.

  In the present embodiment, the case where the temperature sensor 5b and the slow speed rotation time determination unit 102 are provided is described. In this case, it is assumed that the reciprocation period Ts in which the protrusion 6a of the ring 6 reciprocates within the opening 9a of the fixed body 9 is a predetermined time. The motor rotation direction control unit 104 and the motor rotation speed control unit 105 in the drive control unit 10 control the motor 2 so that the protrusion 6a reciprocates in the opening 9a during a predetermined reciprocation period Ts. .

  In the present embodiment, the temperature sensor 5b is provided in the driving device 1, but the temperature of the entire image forming device 11 may be detected by providing the temperature sensor 5b in the image forming device 11 of FIG. When the temperature sensor 5 b is provided in the driving device 1, the number of the temperature sensors 5 b is required as many as the number of the driving devices 1 provided for each photosensitive drum 111, but only one temperature sensor 5 b is required when provided in the entire image forming apparatus 11. Therefore, cost can be reduced.

  In the present embodiment, an example in which the slow rotation time determination unit 102 determines the round trip time Ts based on the round trip time table shown in FIG. 5 is described, but the present invention is not limited to this. The slow speed rotation time determination unit 102 may determine the round trip time Ts based on a reciprocal time calculation formula that can determine the round trip time Ts regardless of the temperature range.

  The drive device of the present invention can be used as a drive device for a color image forming apparatus such as a color printer or a color copying machine.

The figure which showed the cross-sectional structure of the drive device which concerns on this embodiment, and the connection with the peripheral device. 1 is a schematic diagram of an image forming apparatus in which a driving device of the present embodiment is used. FIG. 3 is a sectional view taken along line III-III of the driving device 1 of FIG. 1. The function block diagram of the drive control part of the drive device which concerns on this embodiment. A round trip period table stored in the storage unit. Timing chart of various signals.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Drive device 2 Motor 3 Motor rotating shaft 4 Planetary roller 4a Elastic body 5b Temperature sensor 6 Ring 6a Protrusion part 7 Carrier roller 8 Output shaft 9 Fixed body 9a Opening part

Claims (3)

A plurality of planetary rollers, which are in pressure contact with the outer peripheral surface of the rotating shaft of the motor, and at least partly made of an elastic body, are in contact with the plurality of planetary rollers at the inner peripheral surface, and projecting portions protruding on the outer peripheral surface A ring having a ring and an opening having a width that allows the protrusion to move a predetermined distance at a position corresponding to the protrusion of the ring; and A planetary roller power transmission unit including a carrier roller that rotates in conjunction with the rotation of the planetary roller, and an output shaft that outputs the rotation of the carrier roller to the outside;
Drive control means for controlling the rotation of the motor so that the protrusion of the ring reciprocates within the opening of the fixed body during a predetermined time from the start of the motor;
A driving device including: And further comprising a detecting means for detecting a temperature in the vicinity of the planetary roller or the planetary roller,
The drive control means includes a slow rotation time determination means for determining the predetermined time based on the temperature detected by the detection means, and the image forming process after at least the predetermined time has elapsed since the start of the motor. The drive device according to claim 1, further comprising image processing control means for starting.   The planetary roller reciprocates a predetermined width on the outer peripheral surface of the rotating shaft of the motor around a portion where the planetary roller and the outer peripheral surface of the rotating shaft of the motor are in contact with each other when the rotation of the motor is stopped. The drive device according to claim 1, wherein the drive control means controls rotation of the motor.

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