JP2006060896A - Motor actuator and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a motor actuator, wherein lubricant can be prevented from sticking to an optical sensor placed in a housing case, and to provide an image forming apparatus to which the motor actuator is applied. <P>SOLUTION: In the motor actuator 26 of the image forming apparatus 10, a flange-like lubricant blocking portion 60 that is protruded in the radial direction is formed between the gear portion 52 of an output gear 50 and a light-intercepting rib 58. Therefore, grease applied to the gear portion 52 is held in the groove 62 in the lubricant blocking portion 60 and is prevented from sticking to the light intercepting rib 58. A lubricant-removing portion 70 is formed upstream of an optical sensor 64 in the direction of the rotation of the light-intercepting rib 58 on both sides of the path of rotation of the light-intercepting rib 58. Thus, even if foreign matter, such as grease, sticks to the light intercepting rib 58 by making the light intercepting rib 58 turn toward the optical sensor 64, the greases sticking to the light intercepting rib 58 is removed by the lubricant-removing portion 70. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a motor actuator and an image forming apparatus to which the motor actuator is applied.

  An image forming apparatus such as a copy printer is provided with four photosensitive drums as latent image carriers for yellow, magenta, cyan, and black, and each of the photosensitive drums supported by a plurality of rotatable support rollers. And an endless belt-shaped intermediate transfer belt that moves while in contact with the belt (for example, see Patent Document 1).

  Further, in this way, the image forming apparatus is provided with a motor actuator for partially bringing the intermediate transfer belt into non-contact with each of the photosensitive drums. This motor actuator brings the intermediate transfer belt into contact with all the four color photosensitive drums during color printing, and separates the intermediate transfer belt from the yellow, magenta, and cyan photosensitive drums during monochrome printing. It is like that. As a result, a predetermined toner image corresponding to color printing or monochrome printing is formed on the surface of the intermediate transfer belt.

  Further, such an image forming apparatus includes a transfer roller that presses the intermediate transfer belt and the recording paper between the support rollers, and a motor actuator for driving the transfer roller. This motor actuator moves the transfer roller toward the intermediate transfer belt during printing, and separates the transfer roller from the intermediate transfer belt to prevent contamination while printing is stopped.

  By the way, in the motor actuator as described above, a motor is disposed in a housing case, and an output shaft is rotatably supported in the housing case. The motor rotation shaft and the output shaft have a plurality of gears. Are connected through. Further, such a motor actuator is provided with an optical sensor that detects the rotational position of the output shaft and reads the rotation, and this optical sensor is attached with the lubricant applied to the plurality of gears and the like. In order to avoid, it is arranged outside the housing case.

For this reason, a separate light blocking member for blocking between the light emitter and the light receiver of the optical sensor is required, which causes an increase in the cost due to an increase in the number of parts and an increase in the number of assembly steps. Yes. In addition, since the light blocking member rotates outside the housing case, there is a risk of involving other parts, the operator's fingers, etc., and there is a problem of damage to the device or a problem of ensuring the safety of the operator. .
JP 2001-242680 A

  In consideration of the above-described facts, the present invention is configured by applying a motor actuator capable of preventing adhesion of lubricant to an optical sensor disposed inside a housing case in order to detect a rotational position of an output shaft, and the motor actuator. An object of the present invention is to obtain an image forming apparatus.

  In order to solve the above-described problem, a motor actuator according to a first aspect of the present invention includes a motor provided inside a housing case, and a light emitter and a light receiver provided inside the housing case and facing each other. An optical sensor, a gear part that is rotatably supported inside the housing case and is rotated by transmitting the rotational force of the motor, and is provided on one side in the axial direction of the gear part and rotates integrally with the gear part. Thus, an output gear having a light blocking rib that passes between the light emitter and the light receiver of the optical sensor, and a lubricant applied to the gear portion of the output gear are passed through the light blocking rib. Lubricant adhesion preventing means for preventing adhesion to the light emitting body and the light receiving body of the optical sensor is provided.

  In the motor actuator according to the first aspect, when the motor provided in the housing case rotates, the gear portion of the output gear rotatably supported in the housing case rotates. This output gear is provided with a light blocking rib on one side in the axial direction of the gear portion, and this light blocking rib rotates integrally with the gear portion, so that an optical sensor provided inside the housing case. Between the light emitter and the light receiver. Thereby, the position of the output gear can be detected. For example, if the output shaft is coaxially and integrally connected to the output gear, the position of the output shaft can be detected.

  Here, the motor actuator includes a lubricant adhesion preventing means for preventing the lubricant applied to the gear portion of the output gear from adhering to the light emitter and the light receiver of the optical sensor via the light blocking rib. . Therefore, it is possible to prevent the lubricant from adhering to the light emitter and the light receiver of the optical sensor while the optical sensor is provided in the housing case together with the motor and the output gear. Thereby, for example, malfunction of the apparatus due to adhesion of the lubricant to the light emitter and the light receiver of the optical sensor can be prevented.

  A motor actuator according to a second aspect of the present invention is the motor actuator according to the first aspect, wherein the lubricant adhesion preventing means is provided between the gear portion of the output gear and the light blocking rib. And a lubricant blocking portion that holds the lubricant applied to the portion and prevents adhesion to the light blocking rib.

  In the motor actuator according to claim 2, a lubricant blocking portion is provided between the gear portion of the output gear and the light blocking rib, and the lubricant blocking portion holds the lubricant applied to the gear portion. Thus, adhesion to the light blocking rib is prevented. Thereby, it is possible to prevent the lubricant applied to the gear portion of the output gear from adhering to the light emitter and the light receiver of the optical sensor through the light blocking rib.

  The motor actuator according to a third aspect of the present invention is the motor actuator according to the first or second aspect, wherein the lubricant adhesion preventing means is upstream of the photosensor in the rotation direction of the light blocking rib and It is characterized by comprising a lubricant removing section that is provided on both sides of the rotation path of the light blocking rib and removes the lubricant attached to the light blocking rib.

  According to a third aspect of the present invention, the lubricant removing portion is provided on the upstream side of the optical sensor in the rotation direction of the light blocking rib and on both sides of the rotation path of the light blocking rib. Therefore, for example, even when the lubricant applied to the gear portion of the output gear adheres to the light blocking rib, the lubricant attached to the light blocking rib is lubricated by rotating the light blocking rib toward the optical sensor. It is removed by the agent removing unit. Thereby, it is possible to prevent the lubricant from adhering to the light emitter and the light receiver of the optical sensor.

  A motor actuator according to a fourth aspect of the present invention is the motor actuator according to the third aspect, wherein the lubricant removing portion is in sliding contact with the light blocking rib.

  In the motor actuator according to the fourth aspect of the present invention, since the lubricant removing portion is in sliding contact with the light blocking rib, it can be reliably removed even when the lubricant adheres to the light blocking rib.

  A motor actuator according to a fifth aspect of the present invention is the motor actuator according to the third or fourth aspect, wherein the lubricant removing section includes a discharge hole for discharging the removed lubricant. It is said.

  In the motor actuator according to the fifth aspect, the lubricant removed by the lubricant removing portion is discharged from a discharge hole provided in the lubricant removing portion. Therefore, it is possible to prevent the lubricant from accumulating on the lubricant removing portion.

  According to a sixth aspect of the present invention, there is provided a motor actuator comprising: a motor provided in a housing case; an optical sensor provided in the housing case having a light emitter and a light receiver facing each other; and rotation of the motor. A first gear that is connected to the shaft and coated with a lubricant and rotates integrally with the rotating shaft, and a motor-side gear that meshes with the first gear and transmits the rotational force of the first gear to rotate at a reduced speed. And an intermediate gear having an output side gear portion that is coaxial with the motor side gear portion and displaced in the axial direction and rotates integrally with the motor side gear portion, and rotates inside the housing case A gear part that is freely supported and is rotated by transmitting the rotational force of the output side gear part of the intermediate gear, and is provided on one side in the axial direction of the gear part, and rotates integrally with the gear part. An output gear having a light blocking rib passing between the light emitting element and the photoreceptor of the optical sensor in Rukoto is characterized by comprising.

  In the motor actuator according to claim 6, when the rotation shaft of the motor provided inside the housing case rotates, the first gear connected to the rotation shaft rotates, and the motor side gear portion meshes with the first gear. The intermediate gear rotates at a reduced speed. The motor side gear portion of the intermediate gear is provided with an output side gear portion that is coaxial and displaced in the axial direction, and this output side gear portion rotates integrally with the motor side gear portion. Further, the rotational force of the output side gear portion of the intermediate gear is transmitted to the gear portion of the output gear, and the output gear rotates. This output gear is provided with a light blocking rib on one side in the axial direction of the gear portion, and this light blocking rib rotates integrally with the gear portion, so that an optical sensor provided inside the housing case. Between the light emitter and the light receiver. Thereby, the position of the output gear can be detected. For example, if the output shaft is coaxially and integrally connected to the output gear, the position of the output shaft can be detected.

  Here, in this motor actuator, since the lubricant is applied to the first gear connected to the rotation shaft of the motor, the meshing between the first gear and the motor side gear portion of the intermediate gear becomes smooth. Further, in the intermediate gear, the output side gear portion for transmitting the rotational force of the motor side gear portion to the output gear is provided coaxially with the motor side gear portion and displaced in the axial direction as described above. . For this reason, the lubricant that has adhered to the motor side gear portion of the intermediate gear from the first gear can be prevented from adhering to the output side gear portion. It can prevent adhesion. That is, in this motor actuator, the output side gear portion of the intermediate gear and the gear portion of the output gear are in a greaseless meshing state where no lubricant is applied, but the rotation of the rotation shaft of the motor is the motor of the first gear and the intermediate gear. Since the speed is reduced by the side gear portion and transmitted to the output side gear portion of the intermediate gear and the gear portion of the output gear, the durability does not deteriorate.

  Thus, in this motor actuator, since it is possible to prevent the lubricant from adhering to the gear portion of the output gear, the lubricant adheres to the light emitter and the light receiver of the optical sensor via the gear portion and the light blocking rib. Can be prevented.

  A motor actuator according to a seventh aspect of the present invention is the motor actuator according to the sixth aspect, further comprising a partition plate that partitions the first gear, the intermediate gear, and the output gear.

  In the motor actuator according to the seventh aspect, the first gear, the intermediate gear, and the output gear are partitioned by a partition plate. Therefore, even when the lubricant adhering to the motor-side gear portion of the first gear and the intermediate gear is scattered, the adhesion to the output gear can be prevented.

  The motor actuator according to an eighth aspect of the present invention is the motor actuator according to any one of the first to seventh aspects, wherein the optical sensor is on an upper surface side of the output gear in a properly mounted state of the housing case. It is located in

  In the motor actuator according to the eighth aspect, the optical sensor is located on the upper surface side of the output gear in the normal mounting state of the housing case. Therefore, even when the lubricant adhering to the gear portion of the output gear hangs downward, it does not adhere to the optical sensor.

  The image forming apparatus according to claim 9 is a state in which the plurality of latent image carriers arranged side by side and a plurality of support rollers rotatably provided are in contact with the plurality of latent image carriers. The toner image on the surface of the intermediate transfer body is pressed between the belt-shaped intermediate transfer body on which a predetermined toner image is formed by moving the intermediate transfer body and the support roller between the intermediate transfer body and the recording paper. A transfer roller for transferring the intermediate transfer member to a part of the plurality of latent image carriers, and a second drive for separating the transfer roller from the support roller. And at least one of the first drive source and the second drive source is the motor actuator according to any one of claims 1 to 8. It is a feature.

  The image forming apparatus according to claim 9, wherein at least one of a first drive source for separating the intermediate transfer member from a part of the plurality of latent image carriers and a second drive source for separating the transfer roller from the support roller. One is the motor actuator according to any one of claims 1 to 8. Therefore, it is preferable.

<First Embodiment>
FIG. 1 schematically shows the configuration of an image forming apparatus 10 according to the first embodiment of the present invention.

  The image forming apparatus 10 includes an endless belt-like intermediate transfer belt 16 as an intermediate transfer member that is wound around and supported by a pair of support rollers 12 and 14. The intermediate transfer belt 16 moves at a constant speed in the direction of arrow A shown in FIG. 1 as the support rollers 12 and 14 rotate.

  On the upper side of the intermediate transfer belt 16, four drum-shaped photosensitive drums 18 Y, 18 M, 18 C, and 18 B as latent image carriers for the respective colors of yellow, magenta, cyan, and black are in contact with the intermediate transfer belt 16. Are arranged side by side. These photoreceptor drums 18Y, 18M, 18C, and 18B are charged, exposed, and developed so that a predetermined toner image is formed on the outer peripheral portion. The formed toner image is an intermediate transfer belt. 16 is transferred to the surface.

  On the other hand, a sheet tray 22 for storing the recording sheet 20 is provided below the intermediate transfer belt 16. A half-moon roller (not shown) is disposed in the vicinity of the paper discharge portion in the paper tray 22, and the recording paper 20 is sent out one by one by the half-moon roller. The fed recording paper 20 is conveyed in the direction of the support roller 12 by a conveyance roller (not shown).

  The recording paper 20 conveyed to the support roller 12 is inserted between the support roller 12 (intermediate transfer belt 16) and a transfer roller 24 arranged in parallel with the support roller 12. The transfer roller 24 is always urged toward the support roller 12 by an urging member (not shown), and the recording paper 20 inserted between the transfer roller 24 and the intermediate transfer belt 16 is transferred by the transfer roller 24 to the intermediate transfer belt 16. To be pressed. As a result, the toner image transferred to the surface of the intermediate transfer belt 16 is transferred to the recording paper 20.

  Further, the recording paper 20 that has passed between the intermediate transfer belt 16 (support roller 12) and the transfer roller 24 is conveyed to a fixing device (not shown), and an unfixed toner image on the recording paper 20 is fixed by the fixing device. It has become so.

  On the other hand, the image forming apparatus 10 includes a motor actuator 26 as a first drive source for separating the intermediate transfer belt 16 from the photosensitive drums 18Y, 18M, and 18C. The motor actuator 26 separates the intermediate transfer belt 16 from the photosensitive drums 18Y, 18M, and 18C via a driving mechanism (not shown) during monochrome printing, and all the photosensitive members during color printing. The intermediate transfer belt 16 is brought into contact with the drums 18Y, 18M, 18C, and 18B.

  Further, the image forming apparatus 10 includes a motor actuator 28 as a second drive source for separating the transfer roller 24 from the support roller 12 (intermediate transfer belt 16). The motor actuator 28 prevents the transfer roller 24 from being soiled by separating the transfer roller 24 from the support roller 12 (intermediate transfer belt 16) via a drive mechanism (not shown) while printing is stopped. In other words, the separation of the transfer roller 24 is released, and the recording paper 20 is pressed against the intermediate transfer belt 16 by the transfer roller 24.

  Here, FIG. 2 is a perspective view showing the overall configuration of the motor actuators 26 and 28. 3 and 4 are plan views showing the configuration of the main parts of the motor actuators 26 and 28. FIG.

  As shown in these drawings, the motor actuator 26 includes a housing case 30. The housing case 30 has a case main body 32 and a cover 34. The housing case 30 has a configuration in which the case main body 32 is on the upper side and the cover 34 is on the lower side in a normal attachment state to the image forming apparatus 10.

  A motor 36 is provided inside the case body 32. A first gear 40 that is a worm gear is integrally connected to a rotation shaft 38 of the motor 36. An intermediate gear 42 is rotatably supported inside the case body 32 at the side of the first gear 40. The intermediate gear 42 has a motor-side gear portion 44 with worm wheel teeth formed on the outer peripheral portion, and the motor-side gear portion 44 meshes with the first gear 40. Thus, when the first gear 40 rotates, the intermediate gear 42 rotates at a reduced speed in the direction of arrow E in FIG.

  An output side gear portion 46 that is a spur gear is provided on one side in the axial direction of the motor side gear portion 44. The output side gear portion 46 is provided coaxially with the motor side gear portion 44 and displaced in the axial direction, and rotates integrally with the motor side gear portion 44.

  A second intermediate gear 48 that is a spur gear is provided on the opposite side of the output side gear portion 46 from the first gear 40 in the radial direction. The second intermediate gear 48 is rotatably supported by the case main body 32 in a state where the second intermediate gear 48 is engaged with the output side gear portion 46. Thus, when the intermediate gear 42 rotates in the direction of arrow E in FIG. 3, the second intermediate gear 48 rotates at a reduced speed in the direction of arrow F in FIG.

  Further, an output gear 50 is provided on the opposite side to the intermediate gear 42 in the radial direction of the second intermediate gear 48. The output gear 50 includes a gear portion 52 that is a spur gear that meshes with the second intermediate gear 48, and an output shaft 54 that is provided integrally with the shaft center portion of the gear portion 52 is connected to the case body 32. The bearing portion 56 formed on the upper wall 32A is rotatably supported. Accordingly, when the second intermediate gear 48 rotates in the direction of arrow F in FIG. 3, the output gear 50 rotates at a reduced speed in the direction of arrow G in FIG. 3 integrally with the output shaft 54.

  The output gear 50 has a light blocking rib 58 having a semicircular cross section formed integrally and concentrically with the gear portion 52 on the end face on one side in the axial direction of the gear portion 52 (the bearing portion 56 side). Yes. The light blocking rib 58 is provided in a range of 180 degrees along the circumferential direction of the gear portion 52, and rotates integrally with the gear portion 52 around the output shaft 54. The light blocking rib 58 corresponds to an optical sensor 64 (for example, a photo interrupter) described later.

  Further, as shown in FIG. 5, the output gear 50 is provided with a brim-like lubricant blocking portion 60 protruding in the radial direction between the gear portion 52 and the light blocking rib 58. The lubricant blocking portion 60 is formed with a groove 62 that opens toward the other side in the axial direction of the gear portion 52 (the side opposite to the light blocking rib 58).

  On the other hand, the optical sensor 64 described above is for detecting the rotational position of the output shaft 54 (output gear 50) and reading the rotation. The optical sensor 64 is fixed to the upper wall 32A of the case body 32 on one side in the axial direction of the output gear 52 (on the light blocking rib 58 side), and has a light emitting portion 66 and a light receiving portion 68 that face each other. Yes. The light emitting unit 66 and the light receiving unit 68 are provided on both sides (inner peripheral side and outer peripheral side) of the rotation path of the light blocking rib 58 of the output gear 50, and the light emitting unit is rotated by rotating the output gear 50. A light blocking rib 58 passes between 66 and the light receiving portion 68.

  The upper wall 32A of the case body 32 is provided with a lubricant removing portion 70 on the upstream side of the optical sensor 64 in the rotation direction of the light blocking rib 58 and on both sides of the rotation path of the light blocking rib 58.

  As shown in FIG. 6, a slit 74 is formed in the lubricant removing portion 70 at a position corresponding to the rotation path of the light blocking rib 58 of the output gear 50, and a portion around the slit 74 is connected to the optical sensor 64. Protrudes toward the opposite side. The width dimension B of the slit 74 is slightly wider than the width dimension C of the light blocking rib 58 and is narrower than the distance dimension C between the light emitter 66 and the light receiver 68 of the optical sensor 64. The light shielding rib 58 of the output gear 50 passes between the slits 74.

  A grease avoiding wall 72 is provided on the opposite side of the lubricant removing unit 70 via the optical sensor 64.

  On the other hand, in the motor actuator 10, the motor side gear portion 44 of the first gear 40, the intermediate gear 42, the output side gear portion 46 of the intermediate gear 42, the second intermediate gear 48, and the gear portion 52 of the output gear 50 described above. Each tooth part is configured to be coated with grease as a lubricant.

  On the other hand, the motor actuator 28 has the same configuration as the motor actuator 26 described above.

  Next, the operation of the first embodiment will be described.

  In the image forming apparatus 10 configured as described above, when a monochrome image is printed on the recording paper 20, power is supplied to the motor 36 of the motor actuator 26, and the rotation shaft 38 of the motor 36 rotates. When the rotating shaft 38 rotates, the first gear 40 rotates integrally with the rotating shaft 38, and the intermediate gear 42 in which the motor-side gear portion 44 meshes with the first gear 40 rotates at a reduced speed in the direction of arrow E in FIG. Therefore, the second intermediate gear 48 meshed with the output side gear portion 46 of the intermediate gear 42 decelerates and rotates in the direction of arrow F in FIG. 3, and the output gear 50 with the gear portion 52 meshed with the second intermediate gear 48 The motor rotates at a reduced speed in the direction of arrow G in FIG. 3, and the output shaft 54 rotates together with the output gear 50. Then, when the light blocking rib 58 of the output gear 50 passes between the light emitter 66 and the light receiver 68 of the optical sensor 64, the rotational position of the output gear 50 (output shaft 54) is detected, and the output shaft 54 is The rotation of the motor 36 is stopped when it is detected that it has rotated 180 degrees in the direction of arrow G in FIG. As a result, the intermediate transfer belt 16 is separated from the photosensitive drums 18Y, 18M, and 18C via a drive mechanism (not shown).

  On the other hand, electric power is also supplied to the motor 36 of the motor actuator 28, the output shaft 54 rotates in the direction of arrow G in FIG. 3, and the rotation of the motor 36 is stopped when the output shaft 54 rotates 180 degrees. In this state, the transfer roller 24 is moved toward the support roller 12 by the urging force of the urging member.

  On the other hand, the photosensitive drum 18B is charged, exposed and developed to form a toner image, and the formed toner image is transferred to the surface of the intermediate transfer belt 16 (primary transfer). Further, the recording paper 20 in the paper tray 22 is inserted between the transfer roller 24 and the support roller 12 and is pressed against the intermediate transfer belt 16 by the transfer roller 24. As a result, the toner image is transferred from the intermediate transfer belt 16 onto the recording paper 20 (secondary transfer). The recording paper 20 is conveyed to a fixing device (not shown), and the unfixed toner image on the recording paper 20 is fixed by the fixing device.

  When printing as described above is completed, electric power is supplied to the motor 36 of the motor actuator 28, the output shaft 54 is rotated in the direction of arrow G in FIG. 3, and the output shaft 54 is rotated 180 degrees. The rotation is stopped. As a result, the motor actuator 28 moves the transfer roller 24 away from the support roller 12 (intermediate transfer belt 16) via a drive mechanism (not shown). Thereby, the transfer roller 24 is prevented from being soiled.

  In the image forming apparatus 10, when a color image is printed on the recording paper 20, power is supplied to the motor 36 of the motor actuator 26, and the output shaft 54 is rotated in the direction of arrow G in FIG. 3. The rotation of the motor 36 is stopped when the output shaft 54 rotates 180 degrees. In this state, the intermediate transfer belt 16 contacts all the photosensitive drums 18Y, 18M, 18C, and 18B.

  On the other hand, electric power is also supplied to the motor 36 of the motor actuator 28, the output shaft 54 rotates in the direction of arrow G in FIG. 3, and the rotation of the motor 36 is stopped when the output shaft 54 rotates 180 degrees. In this state, the transfer roller 24 is moved toward the support roller 12 by the urging force of the urging member.

  On the other hand, the photosensitive drums 18Y, 18M, 18C, and 18B are charged, exposed, and developed to form toner images, and the formed toner images are transferred to the surface of the intermediate transfer belt 16 (primary transfer). ). Further, the recording paper 20 in the paper tray 22 is inserted between the transfer roller 24 and the support roller 12 and is pressed against the intermediate transfer belt 16 by the transfer roller 24. As a result, the toner image is transferred from the intermediate transfer belt 16 onto the recording paper 20 (secondary transfer). The recording paper 20 is conveyed to a fixing device (not shown), and the unfixed toner image on the recording paper 20 is fixed by the fixing device.

  When printing as described above is completed, electric power is supplied to the motor 36 of the motor actuator 28, the output shaft 54 rotates in the direction of arrow G in FIG. 3, and the motor 36 rotates when the output shaft 54 rotates 180 degrees. Is stopped. As a result, the motor actuator 28 moves the transfer roller 24 away from the support roller 12 (intermediate transfer belt 16) via a drive mechanism (not shown). Thereby, the transfer roller 24 is prevented from being soiled.

  Here, in the motor actuators 26 and 28 of the image forming apparatus 10, a brim-like lubricant blocking portion 60 protruding in the radial direction is provided between the gear portion 52 of the output gear 50 and the light blocking rib 58. ing. In addition, since the groove 62 that opens to the opposite side of the light blocking rib 58 is formed in the lubricant blocking portion 60, the grease applied to the gear portion 52 is caused by the groove 62 of the lubricant blocking portion 60. It is held and adhesion to the light blocking rib 58 is prevented. Thereby, it is possible to prevent grease from adhering to the light emitter 66 and the light receiver 68 of the optical sensor 64.

  Further, in the motor actuators 26 and 28 of the image forming apparatus 10, the lubricant removing unit 70 is provided on the upstream side of the optical sensor 64 in the rotation direction of the light blocking rib 58 and on both sides of the rotation path of the light blocking rib 58. The width dimension B of the slit 74 through which the light blocking rib 58 is provided is slightly wider than the width dimension C of the light blocking rib 58, and the distance between the light emitter 66 and the light receiver 68 of the optical sensor 64. It is formed narrower than the dimension C. Therefore, even if foreign matter such as grease adheres to the light blocking rib 58, the light blocking rib 58 rotates toward the optical sensor 64, so that the grease attached to the light blocking rib 58 is removed from the lubricant removing portion. 70 to remove. Thereby, it is possible to prevent foreign matters such as grease from adhering to the light emitter 66 and the light receiver 68 of the optical sensor 64.

  Further, in the motor actuators 26 and 28 of the image forming apparatus 10, the optical sensor 64 is positioned on the upper surface side (light blocking rib 58 side) of the output gear 50 in the normal mounting state of the housing case 30. Therefore, even when the grease applied to the gear portion 52 of the output gear 50 hangs downward, it is preferable that the grease does not adhere to the optical sensor 64.

  As described above, in the motor actuators 26 and 28 of the image forming apparatus 10 according to the first embodiment, the optical sensor 64 disposed inside the housing case 30 is used to detect the rotational position of the output shaft 54 and the like. Can prevent adhesion of grease.

  Therefore, in the motor actuators 26 and 28, the optical sensor 64 can be used even inside the housing case 30 that is easily affected by grease, and a light blocking member that rotates outside the housing case is unnecessary in the conventional motor actuator. become. As a result, the number of parts and the number of assembling steps can be reduced, and the risk of involving other parts, the operator's fingers, and the like at the time of assembling is eliminated, and a reduction in space can be achieved.

Next, a modification of the output gear 50 according to the first embodiment will be described.
(First modification)
FIG. 7 is a side view showing a configuration of an output gear 80 according to a first modification of the output gear 50 according to the first embodiment.

  As shown in FIG. 7, the output gear 80 has basically the same configuration as that of the output gear 50 described above, but instead of the lubricant blocking portion 60 described above between the gear portion 52 and the light blocking rib 58. A brim-like lubricant blocking portion 82 that protrudes in the radial direction of the gear portion 52 is provided. The lubricant blocking part 82 has a configuration in which the groove 62 in the lubricant blocking part 60 described above is omitted.

In this output gear 80 as well, the grease applied to the gear portion 52 by the lubricant blocking portion 82 can be held and adhesion to the light blocking rib 58 can be prevented.
(Second modification)
FIG. 8 is a side view showing the configuration of the output gear 84 according to the second modification of the output gear 50 according to the first embodiment.

  As shown in FIG. 8, the output gear 84 has basically the same configuration as that of the output gear 50 described above, but instead of the lubricant blocking portion 60 described above, between the gear portion 52 and the light blocking rib 58. In addition, a lubricant blocking portion 86 which is a groove (concave portion) formed along the circumferential direction of the gear portion 52 is provided.

Also in the output gear 84, the grease applied to the gear portion 52 by the lubricant blocking portion 86 can be held and adhesion to the light blocking rib 58 can be prevented.
(Third Modification)
FIG. 9 is a side view showing the configuration of the output gear 88 according to a third modification of the output gear 50 according to the first embodiment.

  As shown in FIG. 9, the output gear 88 has basically the same configuration as that of the output gear 50 described above, but instead of the lubricant blocking portion 60 described above between the gear portion 52 and the light blocking rib 58. Further, a cylindrical lubricant blocking portion 90 having a short axial direction covering the light blocking rib 58 is provided.

  Also in the output gear 88, the grease applied to the gear portion 52 by the lubricant blocking portion 90 can be held and adhesion to the light blocking rib 58 can be prevented.

Next, a modification of the lubricant removing unit 70 according to the first embodiment will be described.
(First modification)
FIG. 10 is a plan view showing the configuration of peripheral members including the lubricant removal unit 92 according to the first modification of the lubricant removal unit 70 according to the first embodiment.

  As shown in FIG. 10, the lubricant removing unit 92 has basically the same configuration as the lubricant removing unit 70 described above, but the lubricant removing unit 92 has a light blocking function at the central portion in the thickness direction. A discharge hole 96 for discharging the grease removed from the rib 58 is formed along the longitudinal direction.

Also in the lubricant removing portion 92, foreign matters such as grease adhering to the light blocking rib 58 can be removed. Moreover, the discharge holes 96 are preferable because it is possible to prevent foreign substances such as grease from accumulating around the slits 74.
(Second modification)
FIG. 11 is a plan view showing the configuration of peripheral members including the lubricant removing unit 100 according to the second modification of the lubricant removing unit 70 according to the first embodiment.

  As shown in FIG. 11, the lubricant removing unit 100 includes a pair of removal walls 104, 106 provided on the upstream side of the optical sensor 64 in the rotation direction of the light blocking rib 58 and on both sides of the rotation path of the light blocking rib 58. It has. The pair of removal walls 104 and 106 are arranged in a C shape in plan view so that the distance between them becomes narrower as the optical sensor 64 is approached. The pair of removal walls 104 and 106 are formed with a plurality of discharge holes 108 penetrating in the thickness direction. Further, a grease avoiding wall 110 provided along the opposing direction of the light emitting unit 66 and the light receiving unit 68 is connected to the end of the pair of removal walls 104 and 106 on the optical sensor 64 side.

Also in the lubricant removing unit 100, foreign substances such as grease attached to the light blocking ribs 58 can be removed by the pair of removing walls 104 and 106. In addition, since foreign matters such as grease removed by the pair of removal walls 104 and 106 are discharged from the discharge hole 108, foreign matters such as grease can be prevented from being deposited on the pair of removal walls 104 and 106.
(Third Modification)
FIG. 12 is a plan view showing the configuration of peripheral members including the lubricant removal unit 112 according to the third modification of the lubricant removal unit 70 according to the first embodiment.

  As shown in FIG. 12, the lubricant removing unit 112 is provided on the upstream side of the optical sensor 64 in the rotation direction of the light blocking rib 58 and on both sides (the inner peripheral side and the outer peripheral side) of the rotation path of the light blocking rib 58. It is constituted by a plurality of cylinders 113.

Also in the lubricant removing portion 112, foreign matters such as grease attached to the light blocking rib 58 can be entangled by the column 113.
(Fourth modification)
FIG. 13 is a perspective view showing the configuration of the lubricant removing unit 114 according to a fourth modification of the lubricant removing unit 70 according to the first embodiment.

  As shown in FIG. 13, the lubricant removing portion 114 is a member formed in a U-shaped cross section having a bottom wall 116 and a pair of side walls 118 by sponge or the like, and the optical sensor 64 in the rotation direction of the light blocking rib 58. It is provided on the upstream side and on the rotation path of the light blocking rib 58. A light blocking rib 58 of the output gear 50 is inserted between the pair of side walls 118 of the lubricant removing portion 114.

Also in the lubricant removing portion 114, every time the light blocking rib 58 passes, foreign matters such as grease attached to the light blocking rib 58 can be removed.
(Fifth modification)
FIG. 14 is a perspective view showing the configuration of the lubricant removing unit 120 according to the fifth modification of the lubricant removing unit 70 according to the first embodiment.

  As shown in FIG. 14, the lubricant removing unit 120 is provided on the upstream side of the optical sensor 64 in the rotation direction of the light blocking rib 58, and includes a rubber blade 122 that is in sliding contact with the inner peripheral surface of the light blocking rib 58, The rubber blade 124 is slidably in contact with the outer peripheral surface of the blocking rib 58. The pair of rubber blades 122, 124 are inclined in a direction away from the gear portion 52 toward the downstream side in the rotation direction of the light blocking rib 58, and foreign matters such as grease adhering to the light blocking rib 58 are removed from the gear portion 52. Move to the opposite side and wipe.

In the case of the lubricant removing portion 120, since the pair of rubber blades 122 and 124 are configured to be in sliding contact with the light blocking rib 58, foreign matters such as grease attached to the light blocking rib 58 can be reliably removed.
(Sixth Modification)
FIG. 15 is a perspective view showing a configuration of a lubricant removal unit 126 according to a sixth modification of the lubricant removal unit 70 according to the first embodiment.

  As shown in FIG. 15, the lubricant removing unit 126 includes a pair of brushes 128 and 130 instead of the pair of rubber blades 122 and 124 in the lubricant removing unit 120 described above. Also in the lubricant removing portion 126, foreign matters such as grease adhering to the light blocking rib 58 can be reliably removed.

The above-described lubricant removing units 114, 120, and 126 may be provided alone, or may be provided in combination with any of the above-described lubricant removing units 70, 92, 100, and 112.
<Second Embodiment>
Next, a second embodiment of the present invention will be described. Note that components that are basically the same as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and description thereof is omitted.

  FIG. 16 is a plan view showing the configuration of the main part of the motor actuator 132 according to the second embodiment of the present invention.

  As shown in FIG. 16, the motor actuator 132 has basically the same configuration as the motor actuators 26 and 28 according to the first embodiment, but the output gear 134 has the same structure as that of the first embodiment. The lubricant blocking portion 60 is omitted, and the lubricant removing portion 70 and the grease avoiding wall 72 are also omitted. The case main body 32 is provided with a partition plate 136 that partitions the first gear 40 and the intermediate gear 42 from the output gear 134.

  The motor actuator 132 is configured such that grease is applied only to the first gear 40.

  In the motor actuator 132 configured as described above, since the grease is applied to the first gear 40, the meshing between the first gear 40 and the motor side gear portion 44 of the intermediate gear 42 becomes smooth. Further, in the intermediate gear 42, the output side gear portion 46 that transmits the rotational force of the motor side gear portion 44 to the output gear 50 is provided coaxially with the motor side gear portion 44 and displaced in the axial direction. Yes. For this reason, since the grease adhering to the motor side gear portion 44 of the intermediate gear 42 from the first gear 40 can be prevented from adhering to the output side gear portion 46, naturally the gear of the output gear 134 is output from the output side gear portion 46. It is possible to prevent the grease from adhering to the portion 52. That is, in this motor actuator 132, the output side gear portion 44 of the intermediate gear 42 and the gear portion 52 of the output gear 134 are in a greaseless engagement without applying lubricant, but the rotation of the rotating shaft 38 of the motor 36 is The speed is reduced by the first gear 40 and the motor side gear portion 44 of the intermediate gear 42 and transmitted to the output side gear portion 46 of the intermediate gear 42, the second intermediate gear 48, and the gear portion 52 of the output gear 134. Will not drop.

  Thus, in this motor actuator 132, since it can prevent that grease adheres to the gear part 52 of the output gear 134, the light emitter 66 and the light receiver of the optical sensor 64 via the gear part 52 and the light blocking rib 58. It is possible to prevent grease from adhering to 68.

  The first gear 40, the intermediate gear 42, and the output gear 134 are partitioned by a partition plate 136 provided in the case body 32. Therefore, even when the grease adhering to the motor side gear portion 44 of the first gear 40 and the intermediate gear 42 is scattered, the adhesion to the output gear 134 can be prevented.

  In the second embodiment, the motor actuator 132 has a configuration in which the lubricant blocking unit 60, the lubricant removing unit 70, and the grease avoiding wall 72 are omitted. It is good also as a structure provided with either the interruption | blocking part 60,82,86,90, the lubricant removal part 70,92,100,112,114,120,126 mentioned above and the grease avoidance wall 72. FIG.

FIG.
1 is a schematic diagram illustrating a configuration of an image forming apparatus according to a first embodiment of the present invention. It is a perspective view which shows the structure of the motor actuator which concerns on the 1st Embodiment of this invention. It is a top view which shows the structure of the principal part of the motor actuator which concerns on the 1st Embodiment of this invention. It is a top view which shows the structure of the principal part of the motor actuator which concerns on the 1st Embodiment of this invention. It is a side view which shows the structure of the output gear which concerns on the 1st Embodiment of this invention. It is a top view which shows the structure of the principal part of the motor actuator which concerns on the 1st Embodiment of this invention. It is a side view which shows the 1st modification of the output gear which concerns on the 1st Embodiment of this invention. It is a side view which shows the 2nd modification of the output gear which concerns on the 1st Embodiment of this invention. It is a side view which shows the 3rd modification of the output gear which concerns on the 1st Embodiment of this invention. It is a top view which shows the 1st modification of the lubricant removal part which concerns on the 1st Embodiment of this invention. It is a top view which shows the 2nd modification of the lubricant removal part which concerns on the 1st Embodiment of this invention. It is a top view which shows the 3rd modification of the lubricant removal part which concerns on the 1st Embodiment of this invention. It is a top view which shows the 4th modification of the lubricant removal part which concerns on the 1st Embodiment of this invention. It is a top view which shows the 5th modification of the lubricant removal part which concerns on the 1st Embodiment of this invention. It is a top view which shows the 6th modification of the lubricant removal part which concerns on the 1st Embodiment of this invention. It is a top view which shows the structure of the principal part of the motor actuator which concerns on the 2nd Embodiment of this invention.

Explanation of symbols

  10..Image forming apparatus, 12, 14 .... Support roller, 16 .... Intermediate transfer belt (intermediate transfer member), 18Y, 18M, 18C, 18B..Photosensitive drum (latent image carrier), 20..Recording Paper, 24 ... Transfer roller, 26, 28 ... Motor actuator, 30 ... Housing case, 36 ... Motor, 38 ... Rotary shaft, 40 ... First gear, 42 ... Intermediate gear, 44 ... Motor Side gear part, 46 ... Output side gear part, 50 ... Output gear, 52 ... Gear part, 58 ... Light blocking rib, 60 ... Lubricant blocking part, 64 ... Light sensor, 66 ... Light emitter , 68 .. Photoreceptor, 70 .. Lubricant removal part, 80 .. Output gear, 82 .. Lubricant blocking part, 84 .. Output gear, 86 .. Lubricant blocking part, 88. ..Lubricant blocking part, 92 ..Lubricant removing part, 96 ..Discharge hole, 00 ·· Lubricant removing portion, 108 ·· Discharge hole, 112 ·· Lubricant removing portion, 114 ·· Lubricant removing portion, 120 ·· Lubricant removing portion, 126 ·· Lubricant removing portion, 132 ·· Motor Actuator, 134 ... Output gear, 136 ... Partition plate

Claims (9)

A motor provided inside the housing case;
An optical sensor provided inside the housing case and having a light emitter and a light receiver facing each other;
A gear part that is rotatably supported in the housing case and is rotated by transmitting the rotational force of the motor, and is provided on one side in the axial direction of the gear part so as to rotate integrally with the gear part. An output gear having a light blocking rib passing between the light emitter and the light receiver of an optical sensor;
Lubricant adhesion preventing means for preventing the lubricant applied to the gear portion of the output gear from adhering to the light emitter and the light receiver of the optical sensor via the light blocking rib;
Motor actuator with   The lubricant adhesion preventing means is provided between the gear portion of the output gear and the light blocking rib, and holds the lubricant applied to the gear portion to prevent adhesion to the light blocking rib. The motor actuator according to claim 1, further comprising a lubricant blocking portion.   The lubricant adhesion preventing means is provided on the upstream side of the optical sensor in the rotation direction of the light blocking rib and on both sides of the rotation path of the light blocking rib, and removes the lubricant adhering to the light blocking rib. The motor actuator according to claim 1, further comprising a lubricant removing unit.   The motor actuator according to claim 3, wherein the lubricant removing portion is in sliding contact with the light blocking rib.   5. The motor actuator according to claim 3, wherein the lubricant removing unit includes a discharge hole for discharging the removed lubricant. A motor provided inside the housing case;
An optical sensor provided inside the housing case and having a light emitter and a light receiver facing each other;
A first gear connected to the rotating shaft of the motor and coated with a lubricant and rotating integrally with the rotating shaft;
A motor-side gear portion that meshes with the first gear and transmits the rotational force of the first gear to rotate at a reduced speed; and the motor-side gear that is provided coaxially with the motor-side gear portion and displaced in the axial direction. An intermediate gear having an output side gear portion that rotates integrally with the portion;
A gear portion that is rotatably supported in the housing case and is rotated by a rotational force of the output side gear portion of the intermediate gear, and provided on one side in the axial direction of the gear portion; An output gear having a light blocking rib that passes between the light emitter and the light receiver of the optical sensor by rotating integrally with
Motor actuator with A partition plate that partitions between the first gear and the intermediate gear and the output gear;
The motor actuator according to claim 6. The optical sensor is located on the upper surface side of the output gear in a regular mounting state of the housing case.
The motor actuator according to any one of claims 1 to 7, wherein the motor actuator is provided. A plurality of latent image carriers arranged side by side;
A belt-like intermediate transfer member that is supported by a plurality of rotatably provided support rollers and that forms a predetermined toner image on the surface by moving in contact with the plurality of latent image carriers;
A transfer roller that presses the intermediate transfer member and the recording paper between the support roller and transfers the toner image on the surface of the intermediate transfer member to the recording paper;
A first drive source for separating the intermediate transfer member from a part of the plurality of latent image carriers;
A second drive source for separating the transfer roller from the support roller;
In an image forming apparatus comprising:
At least one of the first drive source and the second drive source is the motor actuator according to any one of claims 1 to 8.
An image forming apparatus.

Images