JP2017083006A - Drive assembly and image formation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drive assembly and an image formation device capable of downsizing the device and reducing device cost.SOLUTION: A color drive assembly 110 comprises: a drive motor such as a color motor 1; a first drive transmission path for transferring the drive power of the drive motor to a first body of rotation such as a photoreceptor drum; drive transmission switching means that is switchable between a state of transferring the drive force of the drive motor and a state of blocking the transferring the drive force such as an electromagnetic clutch 7; and a second drive transmission path for transferring the drive power to a second body of rotation such as a development roller. Then the drive transmission switching means is provided in an axis of rotation 17 that rotates integrally with a drive transmission member constituting the first drive transmission path.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a drive device and an image forming apparatus.

  In the image forming apparatus, a drive device that rotates and rotates a rotating body such as a photoconductor and a developing roller is mounted.

  For example, Patent Document 1 discloses a first drive transmission path for driving and transmitting a driving force of a driving motor to a photoconductor as a first rotating body, and a driving force of the driving motor to a developing roller as a second rotating body. A drive device having a second drive transmission path is described. The first drive transmission path for transmitting the driving force to the photoconductor has a large-diameter photoconductor gear that meshes with the motor gear of the motor, and the photoconductor is connected to a joint formed on the shaft portion of the photoconductor gear. ing. The second drive transmission path includes a clutch, an idler gear having a through-hole through which the shaft portion of the photoconductor gear passes with a gap, a developing gear meshing with the idler gear, and a joint formed integrally with the developing gear. It has. The clutch includes an input gear that meshes with the motor gear and an output gear that meshes with the idler gear. The developing roller is provided on the opposite side of the motor gear with respect to the shaft portion of the photosensitive member gear, and is connected to a joint formed integrally with the developing gear.

  However, the drive device described in Patent Document 1 has many drive transmission members that constitute the second drive transmission path, and there is a problem that the cost of the device increases and the size of the device increases.

  In order to solve the above problems, the present invention provides a drive motor, a first drive transmission path for transmitting the drive force of the drive motor to the first rotating body, a state and a drive force for transmitting the drive force of the drive motor. A drive transmission switching means capable of switching between a state of interrupting transmission of the first drive transmission path and a second drive transmission path for transmitting the driving force to the second rotating body. It is provided on a rotary shaft that rotates integrally with a drive transmission member provided in the first drive transmission path.

  According to the present invention, the cost of the device can be reduced and the size of the device can be reduced.

1 is a schematic configuration diagram of a printer according to an embodiment. Expansion explanatory drawing of a process unit. FIG. 3 is a schematic cross-sectional view showing a color driving device and C, M, and Y color process units. (A) is a schematic sectional drawing of the drive device for color | collars. (B) is the figure which looked at the drive device for collars which removed the bracket and the back side board from the back side. The schematic block diagram of an electromagnetic clutch. (A) is a perspective view showing an electromagnetic clutch and a development output gear. (B) is a perspective view of an electromagnetic clutch. (C) is a perspective view of a development output gear. FIG. 4 is a diagram for explaining a drive transmission path to a Y-color photosensitive drum and a drive path to a rotating body of a Y-color developing device. FIG. 6 is a schematic configuration diagram of a color driving device according to a first modification. FIG. 9 is a perspective view of a color driving device according to a second modification. FIG. 10 is a schematic configuration diagram of a color driving device according to a second modification. FIG. 10 is a schematic configuration diagram of a color drive device according to a third modification. The enlarged view of the broken-line part C shown to Fig.11 (a). FIG. 10 is a schematic configuration diagram of a color drive device according to a fourth modification. The timing chart which shows an example of ON / OFF of the motor for a color, and ON / OFF of an electromagnetic clutch. FIG. 5 is a schematic configuration diagram illustrating a color driving device according to a second embodiment. FIG. 5 is a schematic cross-sectional view illustrating a color driving device and C, M, and Y color process units according to a second embodiment. FIG. 10 is a diagram illustrating a drive transmission path to an M color photosensitive drum and a drive path to a rotating body of an M color developing device in the color driving apparatus according to the second exemplary embodiment. The schematic block diagram of the color drive device of the modification A. The schematic block diagram of the color drive device of the modification B. The schematic block diagram of the color drive device of the modification C. The schematic perspective view of the color drive device of the modification D. FIG. 10 is a schematic configuration diagram of a color driving device according to Modification E.

  Hereinafter, an embodiment of an electrophotographic printer 100 will be described as an image forming apparatus to which the present invention is applied. First, a basic configuration of the printer 100 according to the present embodiment will be described. FIG. 1 is a schematic configuration diagram of a printer 100 according to the present embodiment. The printer 100 includes four process units 26K, 26C, 26M, and 26Y for forming black, cyan, magenta, and yellow (hereinafter referred to as K, C, M, and Y) toner images. These use different colors of K, C, M, and Y toners as image forming substances, but otherwise have the same configuration and are replaced when the lifetime is reached.

  FIG. 2 is an enlarged explanatory view of one of the four process units 26K, 26C, 26M, and 26Y. Since the four process units 26K, 26C, 26M, and 26Y are the same except that the color of the toner to be used is different, the subscripts (K, C, M, and Y) indicating the color of the toner to be used are omitted in FIG. doing. As shown in FIG. 2, the process unit 26 includes a drum-shaped photosensitive drum 24 as a latent image carrier, a photosensitive member cleaning device 83, a static eliminator and a charging device 25, and a developing device 23. And. The process unit 26 as an image forming unit can be attached to and detached from the main body of the printer 100 so that consumable parts can be replaced at a time.

  The charging device 25 uniformly charges the surface of the photosensitive drum 24 that is driven to rotate clockwise in the drawing by the driving unit. The uniformly charged surface of the photosensitive drum 24 is exposed and scanned by the laser beam L emitted from the optical writing unit 27 and carries an electrostatic latent image for each color. This electrostatic latent image is developed into a toner image by a developing device 23 using toner. Then, primary transfer is performed on the intermediate transfer belt 22.

  The photoconductor cleaning device 83 removes transfer residual toner adhering to the surface of the photoconductor drum 24 after the primary transfer process. The static eliminator neutralizes residual charges on the photosensitive drum 24 after cleaning. By this charge removal, the surface of the photosensitive drum 24 is initialized and prepared for the next image formation.

  The developing device 23 includes a vertically long hopper portion 86 that stores toner as a developer, and a developing portion 87. An agitator 88 that is rotated by driving means, a toner supply roller 80 as a developer supplying member that is rotated and driven by driving means below the vertical direction, and the like are disposed in a hopper 86 serving as a developer containing portion. Has been. The toner in the hopper 86 moves toward the toner supply roller 80 by its own weight while being agitated by the rotational drive of the agitator 88. The toner supply roller 80 has a metal cored bar and a roller part made of foamed resin or the like coated on the surface of the metal core. The toner accumulated on the lower side of the hopper 86 is applied to the surface of the roller part. Rotate while adhering.

  In the developing unit 87 of the developing device 23, a developing roller 81 that rotates while contacting the photosensitive drum 24 and the toner supply roller 80, and a thinning blade 82 that contacts the tip of the developing roller 81 are disposed. ing. The toner attached to the toner supply roller 80 in the hopper 86 is supplied to the surface of the development roller 81 at a contact portion between the development roller 81 and the toner supply roller 80. When the supplied toner passes through the contact position between the developing roller 81 and the thinning blade 82 as the developing roller 81 rotates, the layer thickness on the surface of the developing roller 81 is regulated. Then, the toner after the regulation of the layer thickness adheres to the electrostatic latent image on the surface of the photosensitive drum 24 in the developing area which is a contact portion between the developing roller 81 and the photosensitive drum 24. By this adhesion, the electrostatic latent image is developed into a toner image.

  Such toner images are formed by the process units 26K, 26C, 26M, and 26Y, and the toner images of the respective colors are formed on the respective photosensitive drums 24 of the process units 26K, 26C, 26M, and 26Y. .

  As shown in FIG. 1, an optical writing unit 27 is disposed above the four process units 26K, 26C, 26M, and 26Y in the vertical direction. The optical writing unit 27 as a latent image writing device optically scans the respective photosensitive drums 24 in the four process units 26K, 26C, 26M, and 26Y by laser light L emitted from a laser diode based on image information. To do. By this optical scanning, an electrostatic latent image for each color is formed on the photosensitive drum 24. In such a configuration, the optical writing unit 27 and the four process units 26K, 26C, 26M, and 26Y make K, C, M, and Y visible images of different colors on the four photosensitive drums 24, respectively. It functions as an image forming means for forming a toner image.

  The optical writing unit 27 irradiates the photosensitive drum 24 through a plurality of optical lenses and mirrors while polarizing the laser light L emitted from the light source by a polygon mirror rotated by a polygon motor in the main scanning direction. is there. As the optical writing unit 27, an optical writing unit that performs optical writing with LED light emitted from a plurality of LEDs of the LED array may be employed.

  Below the four process units 26K, 26C, 26M, and 26Y, a transfer unit 75 is disposed as a belt device that moves the endless intermediate transfer belt 22 endlessly in a counterclockwise direction while stretching. Has been. In addition to the intermediate transfer belt 22, the transfer unit 75 includes a driving roller 76, a tension roller 20, four primary transfer rollers 74K, 74C, 74M, and 74Y, a secondary transfer roller 21, a belt cleaning device 71, a cleaning backup roller 72, and the like. It has.

  The intermediate transfer belt 22, which is a belt member and a transfer belt, is stretched by a driving roller 76, a tension roller 20, a cleaning backup roller 72, and four primary transfer rollers 74K, 74C, 74M, and 74Y disposed inside the loop. It is built. Then, it is moved endlessly in the same direction by the rotational force of the driving roller 76 that is driven to rotate counterclockwise in the drawing by the driving means.

  The four primary transfer rollers 74K, 74C, 74M, and 74Y sandwich the intermediate transfer belt 22 that is endlessly moved in this manner between the photosensitive drums 24K, 24C, 24M, and 24Y. By this sandwiching, four primary transfer nips for K, C, M, and Y where the front surface of the intermediate transfer belt 22 and the photosensitive drums 24K, 24C, 24M, and 24Y abut are formed.

  A primary transfer bias is applied to the primary transfer rollers 74K, 74C, 74M, and 74Y by a transfer bias power source. As a result, a transfer electric field is formed between the electrostatic latent images on the photosensitive drums 24K, 24C, 24M, and 24Y and the primary transfer rollers 74K, 74C, 74M, and 74Y. Instead of the primary transfer roller 74, a transfer charger or a transfer brush may be employed.

  The Y color toner image formed on the surface of the photosensitive drum 24Y of the process unit 26Y enters the above-described primary transfer nip for Y as the photosensitive drum 24Y rotates. In the primary transfer nip for Y, the Y-color toner image is primarily transferred from the photosensitive drum 24Y onto the intermediate transfer belt 22 by the action of the transfer electric field and nip pressure. The intermediate transfer belt 22 onto which the Y-color toner image has been primarily transferred in this way passes over the primary transfer nips for M, C, and K along with the endless movement of the intermediate transfer belt 22 on the photosensitive drums 24M, 24C, and 24K. The M, C, and K color toner images are sequentially superimposed on the Y color toner image and are primarily transferred. A four-color toner image is formed on the intermediate transfer belt 22 by the primary transfer of the superposition.

  The secondary transfer roller 21 of the transfer unit 75 is disposed outside the loop of the intermediate transfer belt 22 and sandwiches the intermediate transfer belt 22 between the tension roller 20 inside the loop. By this sandwiching, a secondary transfer nip where the front surface of the intermediate transfer belt 22 and the secondary transfer roller 21 abut is formed. A secondary transfer bias is applied to the secondary transfer roller 21 by a transfer bias power source. By this application, a secondary transfer electric field is formed between the secondary transfer roller 21 and the tension roller 20 connected to the ground.

  Below the transfer unit 75 in the vertical direction, a paper feed cassette 41 that accommodates a plurality of recording papers stacked in a bundle is slidably attached to the housing of the printer 100. In the paper feed cassette 41, a paper feed roller 42 is brought into contact with the top recording paper in a bundle of paper, and the recording paper is rotated counterclockwise in the figure at a predetermined timing. Send it out toward the paper feed path.

  Near the end of the paper feed path, a registration roller pair 43 composed of two registration rollers is disposed. The registration roller pair 43 stops the rotation of both rollers as soon as a recording sheet serving as a recording member fed from the sheet feeding cassette 41 is sandwiched between the rollers. Then, rotation driving is restarted at a timing at which the sandwiched recording paper can be synchronized with the four-color toner image on the intermediate transfer belt 22 in the above-described secondary transfer nip, and the recording paper is sent out toward the secondary transfer nip.

  The four-color toner image on the intermediate transfer belt 22 that is in close contact with the recording paper at the secondary transfer nip is secondarily transferred onto the recording paper under the influence of the secondary transfer electric field and nip pressure, and combined with the white color of the recording paper. A full color toner image is obtained. The recording paper having the full-color toner image formed on the surface in this way is separated from the secondary transfer roller 21 and the intermediate transfer belt 22 by the curvature when passing through the secondary transfer nip. Then, the toner is sent to a fixing device 40 as a fixing unit via a post-transfer conveyance path.

  The fixing device 40 is provided with a fixing roller 45 including a heat source 45a such as a halogen lamp, and a pressure roller 47 that rotates while contacting the fixing roller 45 with a predetermined pressure. A fixing nip is formed by the pressure roller 47. The recording paper fed into the fixing device 40 is sandwiched between the fixing nips such that the unfixed toner image carrying surface is in close contact with the fixing roller 45. Then, the toner in the toner image is softened by the influence of heating and pressurization, and the full-color image is fixed.

  When the single-sided print mode is set, the recording paper discharged from the fixing device 40 is discharged to the outside as it is. Then, it is stacked on a stack portion constituted by the upper surface of the upper cover 56 of the housing.

  Note that the untransferred toner that has not been transferred to the recording paper adheres to the intermediate transfer belt 22 after passing through the secondary transfer nip. This is cleaned from the belt surface by a belt cleaning device 71 in contact with the front surface of the intermediate transfer belt 22. A cleaning backup roller 72 disposed inside the loop of the intermediate transfer belt 22 backs up the cleaning of the belt by the belt cleaning device 71 from the inside of the loop.

[Example 1]
FIG. 3 shows the color driving device of Example 1 that drives the color photosensitive drums 24C, 24M, and 24Y and the rotating members (the developing roller 81 and the toner supply roller 80) of the color developing devices 23Y, 23M, and 23C, and C. FIG. 3 is a schematic cross-sectional view showing process units 26C, 26M, and 26Y of M, Y colors.
Since the drive transmission mechanism on each process unit side has the same configuration, the C color process unit will be described here.
A color driving device 110 is disposed on the back side of the printer, which is the downstream side in the process unit mounting direction. A driven side photoconductor joint 124 connected to a driving side photoconductor joint 112 attached to the tip of the rotating shaft 17 is provided at the back end of the photoconductor drum 24. The driven photoconductor joint 124 is rotatably supported by the case 126 of the process unit via a bearing.

  Further, a driven side developing gear 180 in which a driven gear portion 180b and a driven side developing joint portion 180a are integrally formed is provided at the back end portion of the toner supply roller 80 of the developing device 23. A developing roller gear 181 is provided at the back end of the developing roller 81, and the developing roller gear 181 meshes with the driven gear portion 180b via the developing idler gear 182. The driven side developing joint portion 180 a is connected to the driving side developing joint portion 8 b of the driving side developing gear 8.

FIG. 4A is a schematic cross-sectional view of the color driving device 110 according to the first embodiment, and FIG. 4B illustrates the color driving device according to the first embodiment from which the bracket 9 and the back side plate 10 are removed from the back side. FIG.
As shown in FIG. 4A, the color driving device 110 according to the first embodiment includes a color motor 1. The color motor 1 is provided on the side opposite to the surface of the bracket 9 on the process unit side. It is fixed to the surface. The motor shaft of the color motor 1 passes through the bracket 9. Further, teeth are formed on the outer periphery of the motor shaft to form the motor gear 2.

  Between the bracket 9 and the back side plate 10 facing the process unit side surface of the bracket 9, a Y-color photosensitive gear 3Y, an M-color photosensitive gear 3M, a C-color photosensitive gear 3C, and an idler gear are provided. 11 is disposed. The Y-color photoconductor gear 3Y and the M-color photoconductor gear 3M are engaged with the motor gear 2 of the color motor 1. The idler gear 11 meshes with the M-color photoconductor gear 3M and the C-color photoconductor gear 3C.

  The photoconductor gears 3Y, 3M, and 3C are fixed to rotating shafts 17Y, 17M, and 17C that are rotatably supported by the bracket 9 and the back side plate 10, respectively. Drive-side photoconductor joints 112Y, 112M, and 112c are attached to the tips of the rotation shafts 17Y, 17M, and 17C. The rotary shafts 17Y, 17M, and 17C are provided with electromagnetic clutches 7Y, 7M, and 7C and development output gears 6Y, 6M, and 6C.

  The color driving device 110 according to the first embodiment includes driving-side developing gears 8Y, 8M, and 8C. The driving-side developing gears 8Y, 8M, and 8C are provided on a support shaft provided on the back side plate 10. It is supported rotatably. Each of the drive side development gears 8Y, 8M, and 8C is integrally formed with a development gear portion 8a that meshes with the development output gears 6Y, 6M, and 6C and a drive side development joint portion 8b.

Next, the electromagnetic clutch will be described. Since the electromagnetic clutches of the respective colors have the same configuration, the following description will be made with the color code omitted.
FIG. 5 is a schematic configuration diagram of the electromagnetic clutch 7. 6A is a perspective view showing the electromagnetic clutch 7 and the development output gear 6. FIG. 6B is a perspective view of the electromagnetic clutch 7. FIG. 6C is a development output. 3 is a perspective view of a gear 6. FIG.
As shown in FIG. 5, the electromagnetic clutch 7 serving as drive transmission switching means includes a shaft fixing portion 7e, an electromagnetic coil portion 7d, a rotor portion 7c, an armature 7b, and the like. The shaft fixing portion 7e has an insertion hole into which the rotating shaft 17 is inserted, and the insertion hole has a D-shaped cross section. The rotating shaft 17 has a D-shaped section cut out so as to be fitted with the D-shape. By fitting the D-shaped section of the shaft fixing portion 7 e with the D-shaped section of the rotating shaft 17, the shaft fixing portion 7 e is fixed so as to rotate with the rotating shaft 17.

An electromagnetic coil portion 7d is rotatably attached to the shaft fixing portion 7e with respect to the shaft fixing portion 7e. On the other hand, the rotor portion 7c is fixed to the shaft fixing portion 7e so as to rotate integrally with the shaft fixing portion 7e. An armature 7b made of a metal disk is attached to a clutch drive transmission member 7f having a pair of drive claws 7a extending to the development output gear side.
As shown in FIGS. 5 and 6C, a pair of fitting holes 6a are formed on the surface of the development output gear 6 facing the electromagnetic clutch 7, and a clutch drive transmission member is formed in the fitting holes 6a. 7f drive claw 7a is fitted.

  The clutch drive transmission member 7f integrated with the armature 7b has a predetermined clearance with respect to the shaft fixing portion 7e so that the armature 7b is securely attracted to the rotor portion 7c by sliding to the rotor portion 7c side when the clutch is ON. And is attached to the shaft fixing portion 7e. For this reason, the clutch drive transmission member 7f inevitably has a large radial play relative to the rotation axis. As a result, the clutch drive transmission member 7f has a so-called axial misalignment in which the shaft center of the rotation shaft 17 and the rotation shaft center of the clutch drive transmission member 7f are displaced due to its own weight or the like. When the clutch is turned on, the armature 7b of the clutch drive transmission member 7f is brought into close contact with the rotor portion 7c in a state in which this axial misalignment occurs.

  When the armature 7b is attached to the development output gear 6 and the development output gear 6 is used as the clutch drive transmission member 7f, the following problems occur. That is, if the clutch drive transmission member 7f is misaligned when the clutch is ON, the meshing position between the clutch drive transmission member 7f and the developing gear portion 8a varies in the radial direction. As a result, when the distance between the meshing position and the center of the rotating shaft 17 is close, the clutch drive transmission member 7f rotates fast, and when the meshing position is far, the clutch driving transmission member 7f rotates slowly. For this reason, there is a problem that uneven rotation speed occurs in the developing gear portion 8a to which the driving force is transmitted from the clutch drive transmission member 7f, and uneven rotation speed occurs in the developing roller 81Y.

  On the other hand, in the present embodiment, the development output gear 6 is rotatably attached to the rotary shaft 17, and the development output gear 6 is provided with a fitting hole 6a into which the drive claw 7a of the clutch drive transmission member 7f is fitted. The gear 6 and the electromagnetic clutch 7 are drivingly connected from the axial direction. The development output gear 6 may be a gap that can rotate with respect to the rotation shaft 17, and is accurately positioned in the radial direction with respect to the rotation shaft 17. Are in good agreement. Thereby, it is possible to suppress the occurrence of uneven rotation speed in the developing gear portion 8a in the drive transmission between the developing output gear 6 and the developing gear portion 8a.

  Further, by providing the development output gear 6 coaxially with the electromagnetic clutch 7, even when the clutch drive transmission member 7f is misaligned with the rotation shaft 17 when the clutch is ON, the development output gear 6 and There is no occurrence of uneven rotation speed with the clutch drive transmission member 7f. This is because, when the clutch is ON, when the armature 7b of the clutch drive transmission member 7f is in close contact with the rotor portion 7c, the drive claw 7a of the clutch drive transmission member 7f revolves around the axis of the rotary shaft 17. . Similarly, the fitting hole 6 a of the developing output gear 6 attached to the rotating shaft 17 revolves around the axis center of the rotating shaft 17. Thus, since both the drive claw 7a and the fitting hole 6a revolve around the shaft center of the rotary shaft 17, even if the clutch drive transmission member 7f is misaligned with the rotary shaft 17, the clutch drive The connection position between the transmission member 7f and the development output gear 6 does not vary in the radial direction. As a result, it is possible to suppress the occurrence of uneven rotation speed in the drive transmission between the development output gear 6 and the clutch drive transmission member 7f.

FIG. 7 is a diagram for explaining the drive transmission path to the Y-color photosensitive drum and the drive path to the rotating body (developing roller and toner supply roller) of the Y-color developing device.
FIG. 7A shows a drive transmission path when the electromagnetic clutch is OFF, and FIG. 7B shows a drive transmission path when the electromagnetic clutch is ON.
As shown in FIGS. 7A and 7B, from the motor gear 2 to the rotation shaft, the drive transmission path to the photosensitive drum 24, which is the first drive transmission path, and the drive to the rotating body of the developing device. The transmission path is a common drive transmission path. The rotating shaft 17 is divided into a drive transmission path for transmitting the driving force to the photosensitive drum and a drive transmission path for transmitting the driving force to the rotating body of the developing device.

  When the color motor 1 is rotationally driven, the driving force is transmitted to the Y-color photoconductor gear 3Y via the motor gear 2, and the Y-color photoconductor gear 3Y is rotationally driven. When the photoconductor gear 3Y is rotationally driven, the rotary shaft 17Y to which the photoconductor gear 3Y is fixed and the drive side photoconductor joint 112Y fixed to the tip of the rotary shaft 17Y are rotationally driven. Then, as shown in FIG. 3, the driving force is transmitted to the driven side photosensitive joint connected to the driving side photosensitive joint 112Y, and the photosensitive drum 24Y is rotationally driven.

  As shown in FIG. 7A, when the electromagnetic clutch 7Y is OFF, the rotation shaft 17Y rotates idly with respect to the development output gear 6, and no driving force is transmitted from the rotation shaft 17Y to the development output gear 6. On the other hand, as shown in FIG. 7B, when the electromagnetic clutch is ON, the drive transmission path is branched by the rotating shaft 17, and the driving force is transmitted to the development output gear 6Y via the electromagnetic clutch 7, thereby developing output. The gear 6Y is rotationally driven together with the rotary shaft 17Y. Then, the driving force is transmitted to the developing gear portion 8a via the developing output gear 6Y, and the driving side developing gear 8Y is rotationally driven. Then, as shown in FIG. 3, the driving force is transmitted to the driven side developing joint portion 180a connected to the driving side developing joint portion 8b of the driving side developing gear 8Y, and the toner supply roller 80 is rotationally driven. Further, the driving force of the color motor is transmitted to the developing roller 81Y through the driven gear portion 180b, the developing idler gear 182, and the developing roller gear 181, and the developing roller 81Y is rotationally driven.

  Similarly, for M color, the driving force is transmitted from the motor gear 2 to the photoconductor gear 3M. Thereafter, in the same manner as described above, the driving force is transmitted, and the photosensitive drum 24M and the rotating body of the developing device 23M are rotationally driven. The driving force of the color motor is transmitted to the C photoconductor drum 24C through the motor gear 2, the M photoconductor gear 3M, the idler gear 11, the C photoconductor gear 3C, and the driving side photoconductor joint 112c. . Thereafter, drive transmission is performed in the same manner as in FIG.

  In this embodiment, the color motor 1 drives the color photosensitive drums 24Y, 24M, and 24C and the rotating bodies (toner supply roller and developing roller) of the color developing devices 23Y, 23M, and 23C. Therefore, the number of parts is reduced as compared with a drive motor for driving the color photosensitive drums 24Y, 24M, and 24C and a drive motor for driving the rotating bodies of the color developing devices 23Y, 23M, and 23C. it can. Thereby, the cost of the apparatus can be reduced. In addition, the apparatus can be reduced in size.

  In recent years, the quietness of printers has been demanded more than ever. As in this embodiment, a single motor drives the color photosensitive drums 24Y, 24M, and 24C and the rotating bodies of the color developing devices 23Y, 23M, and 23C. Can be reduced. Thereby, the silence of the apparatus can be achieved.

  In the developing device, components such as a developing roller that have a shorter life than the photosensitive drum are mounted. In this embodiment, the electromagnetic clutches 7Y, 7M, and 7C are arranged on the drive path for driving the rotating body (toner supply roller and developing roller) of the developing device. Thus, even when the photosensitive drum needs to be driven to rotate, the electromagnetic clutches 7Y, 7M, and 7C can be turned off to stop the driving of the color developing devices 23Y, 23M, and 23C. Thereby, it is possible to prevent the developing device from reaching the end of its life early.

  For example, when the motor gear 2 is configured to be divided into a path for driving and transmitting to the Y, M, and C color photosensitive drums and a path for driving and transmitting to the Y, M, and C color developing devices, there are the following problems. That is, in order to transmit the drive to the C-color developing device far away from the motor gear 2, it is necessary to provide many gears. As a result, there is a problem that the cost of the apparatus may increase due to an increase in the number of parts, and the apparatus may be increased in size. In addition, gear meshing noise increases. On the other hand, in the present embodiment, the electromagnetic clutch 7 is attached to the rotating shaft to which the photoconductor gear is fixed, and the driving force transmitted to the photoconductor gear is transmitted to the developing device. As a result, the drive transmission path to the photoconductor and the drive transmission path to the developing device can be shared until halfway, the number of gears is reduced, and the color motor is connected to the photosensitive drum and the developing device. A driving force can be transmitted.

  In the present embodiment, an electromagnetic clutch is provided on the rotating shaft to which the photoconductor gear is fixed, so that the developing gear meshing with the developing output gear and the developing driving side joint are integrated on the driving side developing gears 8Y, 8M, 8C. Can be used. Thereby, the number of parts can be reduced. Further, the drive-side developing gears 8Y, 8M, and 8C can be attached to the support shaft fixed to the back side plate 10 so as to be rotatable so that the assembly can be improved.

  Next, a modification of the first embodiment will be described.

[Modification 1]
8A and 8B are schematic configuration diagrams of a color driving device 110A according to Modification 1 which is a first modification of Embodiment 1, FIG. 8A is a schematic cross-sectional view, and FIG. 8B is a rear side plate 10. FIG. 10 is a view of the collar driving device 110A of Modification 1 with the bracket 9 removed, as viewed from the back side.
As shown in FIG. 8, in the first modification, the color motor 1 is attached to the surface of the back side plate 10 facing the process unit.
By attaching the color motor 1 to the surface of the back side plate 10 facing the process unit, the axial length of the color drive device can be shortened compared to the configuration shown in FIG. It is possible to reduce the size of the printer in the axial direction. Further, since the color motor 1 can be disposed on the inner side of the apparatus, the sound generated from the color motor 1 can be shielded by the back side plate 10 or the bracket 9. Thereby, it is possible to suppress the sound generated from the color motor 1 from leaking to the outside of the printer, and it is possible to reduce the noise of the printer.

[Modification 2]
FIG. 9 is a perspective view of a color driving device 110B according to Modification 2 which is a second modification of Example 1, and FIG. 10 is a schematic configuration diagram of the color driving device 110B according to Modification 2. 10A is a schematic cross-sectional view of the color driving device 110B according to the second modification. FIG. 10B illustrates the color driving device 110B according to the second modification in which the back side plate 10 and the bracket 9 are removed. It is the figure seen from the back side. FIG. 10C is a front view of the color driving device 110B according to the second modification in which the back side plate 10 and the bracket 9 are removed.

  In the second modified color driving device 110B, the distance (st pitch) between the shafts (rotating shafts 17) of the photosensitive drums 24 of the respective colors is reduced in order to reduce the size of the printer. As a result of reducing the St pitch, the width of the motor substrate 1a of the color motor 1 and the mounting member 1b becomes larger than the St pitch. As a result, as in the first modification, when a configuration is adopted in which the color motor is disposed inside the apparatus and the motor gear 2 is directly meshed with the photosensitive member gear, the motor substrate 1a and the mounting member 1b interfere with the rotating shaft 17. Resulting in.

  Therefore, in the color driving device 110B of the second modification, the motor idler gear 13 is provided between the motor gear 2 and the photoconductor gear. The motor idler gear 13 meshes with the C-color photoconductor gear 3C and the M-color photoconductor gear 3M. The motor gear 2 of the color motor meshes with the top (highest part) of the motor idler gear 13. In the second modification, an idler gear 11 is provided between the M color photoconductor gear 3M and the Y color photoconductor gear 3Y. Similar to the embodiment and the first modification, the idler gear 11 is provided between the M color photoconductor gear 3M and the C color photoconductor gear 3C, and the motor idler gear 13 is connected to the M color photoconductor gear 3M and Y. It may be provided between the color photoconductor gear 3Y.

  In this configuration, the color driving device is larger in the vertical direction than in the configuration of the first modification, but in the axial direction, the size can be reduced as much as in the first modification. Also, in the color driving device 110B of the second modification, the color motor 1 is disposed on the inner side, so that the motor sound can be prevented from leaking outside the device.

  Further, the engagement with the motor gear 2 which is the first-stage engagement has the highest noise application rate. By making the meshing with the first-stage motor gear having a high noise application rate one, the noise can be reduced compared to the configuration in which the two photoconductor gears are meshed with the first-stage motor gear as in Modification 1 and the embodiment. Can be suppressed.

[Modification 3]
FIG. 11 is a schematic configuration diagram of a color driving device 110 </ b> C according to a third modification that is a third modification of the first embodiment. FIG. 11A is a schematic cross-sectional view of the color driving device 110C according to Modification 3. FIG. 11B shows the color driving device 110C according to Modification 3 with the back side plate 10 and the bracket 9 removed. It is the figure seen from the back side. FIG. 11C is a diagram of the color driving device 110C according to the third modified example from which the back side plate 10 and the bracket 9 are removed as viewed from the front side.

  In the color drive device 110C of the third modification, the motor idler gear is an internal gear 13A. Specifically, the internal gear 13A has a cylindrical shape with the back side closed, and internal teeth are formed on the inner peripheral surface, and external teeth are formed on the outer periphery. The motor gear 2 meshes with the internal teeth of the internal gear, and the Y-color photoconductor gear 3Y and the M-color photoconductor gear 3M mesh with the external teeth of the internal gear.

  By making the motor idler gear an internal gear, the meshing rate with the motor gear 2 is improved, and vibration and noise can be suppressed. Further, the meshing portion with the motor gear 2 can be covered with the internal gear 13A, and the meshing noise can be shielded with the internal gear 13A. Moreover, since the back side of the internal gear 13A is closed, it is possible to suppress the meshing noise from leaking outside. As a result, the device can be made quieter than the color driving device 110B of the second modification.

FIG. 12 is an enlarged view of a broken line portion C shown in FIG.
As shown in FIG. 12, the internal teeth of the internal gear 13 </ b> A and the motor gear 2 that meshes with the internal teeth are helical teeth. Further, the external teeth of the internal gear 13A and the photoreceptor gears 3Y and 3M meshing with the external teeth are also helical teeth.
The helical teeth of the motor gear 2 are helical teeth that are twisted so that the end on the front end side of the motor shaft is located downstream of the end on the rotor side of the motor in the normal rotational direction. As a result, during normal rotation, the color motor receives a thrust force toward the back side plate 10 to which the motor is attached. Thereby, the color motor is pressed against the back side plate 10, and the posture of the color motor can be stabilized during normal driving. Thereby, rotation unevenness can be suppressed. Further, it is possible to suppress the occurrence of vibration of the color motor and reduce the noise of the motor. Note that the normal rotation and normal driving are rotations during image formation and are driving.

  Further, it is preferable that the external teeth of the internal gear 13 </ b> A are teeth that have a twist direction in the same direction as the twist direction of the internal teeth. The internal teeth of the internal gear 13A receive a thrust force on the front side (motor side) of the apparatus as indicated by an arrow X1 in the figure. On the other hand, the external teeth of the internal gear receive a thrust force on the back side of the apparatus. Thereby, the thrust force is offset, and the internal gear can be prevented from contacting the back side plate 10 or contacting the bracket 9.

  The development output gears 6Y and 6M are preferably helical teeth having the same twisting direction as the photoconductor gears 3Y and 3M. By making the external teeth of the internal gear 13A to be helical teeth twisted in the same direction as the internal teeth, the photoreceptor gears 3Y and 3M have a thrust force acting on the inside of the apparatus as indicated by an arrow X2 in the figure. receive. The development output gears 6Y and 6M are helical teeth having the same twisting direction as the photoconductor gears 3Y and 3M, so that the development output gears 6Y and 6M receive a thrust force on the back side of the apparatus. As a result, when the driving force is transmitted to the rotating body of the developing device, the thrust force is canceled, and the photoreceptor gears 3Y and 3M and the developing output gears 6Y and 6M come into contact with the back side plate 10 and the bracket 9. Can be suppressed.

  When the driving force is not transmitted to the rotating body of the developing device, the photoconductor gears 3Y and 3M receive a thrust force acting on the inside of the device as indicated by an arrow X2 in the drawing. Thereby, the photoconductor gears 3Y and 3M can be brought into contact with the inner back side plate 10. As a result, it is possible to suppress noise due to meshing vibrations from leaking to the outside as compared with the case of contacting the bracket 9 outside the apparatus.

[Modification 4]
FIG. 13 is a schematic configuration diagram of a color driving device 110 </ b> D according to the fourth modification that is the fourth modification of the first embodiment. FIG. 13A is a schematic cross-sectional view of the color driving device 110D of the fourth modification, and FIG. 13B shows the color driving device 110D of the fourth modification in which the back side plate 10 and the bracket 9 are removed. It is the figure seen from the back side. FIG. 13C is a view of the collar driving device 110D of Modification 3 from which the back side plate 10 and the bracket 9 are removed as viewed from the front side.

  In general, the electromagnetic clutches 7Y, 7M, and 7C have a shorter life than gears and need to be replaced regularly. When the electromagnetic clutch is disposed inside the photoconductor gear and the development output gear, it is necessary to remove the photoconductor gear and the development output gear when exchanging the electromagnetic clutch, which makes it difficult to replace the electromagnetic clutch. is there.

  Therefore, in the color driving device 110D of the fourth modification, the electromagnetic clutches 7Y, 7M, and 7C are arranged on the same axis with the photoconductor gears 3Y, 3M, and 3C and the development output gear in order to improve the exchangeability of the electromagnetic clutch. Provided outside 6Y, 6M, 6C. Further, a hole 9 a for accessing the electromagnetic clutches 7 </ b> Y, 7 </ b> M, and 7 </ b> C is provided in the bracket 9, and the hole 9 a is closed with a cap member 15.

  In the color driving device 110D of the fourth modification, when replacing the electromagnetic clutch, the outer cover on the back side of the printer is removed to expose the bracket 9. Next, the cap member 15 is removed, and the electromagnetic clutch is exposed from the hole 9 a of the bracket 9. And an electromagnetic clutch is moved to an axial direction, an electromagnetic clutch is removed from a rotating shaft from the hole 9a, and a new electromagnetic clutch is attached to a rotating shaft.

  As described above, in the color driving device 110D of the fourth modification, the electromagnetic clutch can be replaced without removing the bracket 9 by providing the bracket 9 with the hole 9a for accessing the electromagnetic clutch. . Further, the electromagnetic clutch can be exchanged without removing the photoconductor gears 3Y, 3M, 3C and the development output gears 6Y, 6M, 6C from the rotating shaft. Thereby, replacement | exchange of an electromagnetic clutch can be performed easily.

  In the fourth modification, the color motor is attached to the motor attachment surface portion 9c attached to the support shaft 9b extending perpendicularly from the surface of the bracket 9 facing the back side plate 10. Even with this configuration, the color motor 1 can be disposed above the development output gear 6 and the electromagnetic clutch 7. Thereby, compared with the case where the color motor 1 is attached to the surface opposite to the surface facing the back side plate 10 of the bracket 9, the axial length of the color driving device can be shortened. As a result, the size of the printer can be reduced.

FIG. 14 is a timing chart showing an example of ON / OFF of the color motor and ON / OFF of the electromagnetic clutch.
In the driving devices of the embodiment and the first to fourth modifications, an electromagnetic clutch is provided on a rotating shaft that transmits driving force to the photosensitive drum. The electromagnetic clutch generates an impact when switching from ON to OFF or when switching from OFF to ON, and the impact becomes vibration and propagates to the photosensitive drum via the rotating shaft and the photosensitive member joint. Then, the photosensitive drum may vibrate and an abnormal image such as a shock jitter may occur. Therefore, the electromagnetic clutch ON / OFF timing needs to be performed at a timing that does not affect the image.

  When the impact of switching the electromagnetic clutch from OFF to ON affects the uniform charging of the photoreceptor surface by the charging device, the electromagnetic clutch 7 is switched from OFF to ON at the following timing. That is, as shown in FIG. 14, the electromagnetic clutch is turned OFF or ON between the start of the motor driving and the photosensitive drum surface being uniformly charged by the charging device 25 after the photosensitive drum starts rotating. Switch. When the impact of switching the electromagnetic clutch from OFF to ON does not affect the uniform charging on the surface of the photoconductor, the electromagnetic clutch is switched from OFF to between the exposure start timing t3 and the charging start timing t2. It may be switched on. During the exposure process, if the photosensitive drum vibrates due to the impact of switching the electromagnetic clutch from OFF to ON, the electrostatic latent image is affected. Therefore, at least before the exposure starts, the electromagnetic clutch is switched from OFF to ON. It is preferred to do so.

  In FIG. 14, the electromagnetic clutch is switched from ON to OFF after completion of the fixing process. However, the timing of switching the electromagnetic clutch from the ON process to the OFF process after the development process can be advanced as long as the image is not affected. However, if the electromagnetic clutch is switched from ON to OFF during the primary transfer process, the image transferred to the intermediate transfer belt is affected by the vibration of the photosensitive drum. Therefore, it is preferable to switch the electromagnetic clutch from ON to OFF at least after the primary transfer process.

  Further, for example, the impact of switching the electromagnetic clutch from ON to OFF may propagate to other photosensitive drums via the back side plate 10 or the bracket 9 and affect the rotational speed of the other photosensitive drums. is there. In this case, it is preferable to switch the electromagnetic clutch from ON to OFF after the primary transfer process of Y, M, and C colors is completed. Also, if the impact when the electromagnetic clutch is switched from ON to OFF propagates to the intermediate transfer belt via the photosensitive drum and affects the speed of the intermediate transfer belt, the electromagnetic clutch is turned on after the secondary transfer process. It is preferable to switch from to OFF.

  In the above description, the example in which the electromagnetic clutch is provided on the rotating shaft to which the photosensitive member gear is fixed has been described. However, the first driving force is output to the developing device 23 that is a unit including the developing roller 81 serving as the second rotating member. An electromagnetic clutch may be provided on the same axis as the drive side development joint as the two drive output member. Hereinafter, an example in which an electromagnetic clutch is provided coaxially with the driving side development joint will be described as a second embodiment. In the following description, the description of the same configuration as that of the color driving device described in the embodiment will be omitted as appropriate.

[Example 2]
FIG. 15 is a schematic configuration diagram illustrating a color driving device 210 according to the second embodiment.
As shown in FIG. 15, the color driving device 210 according to the second embodiment includes a Y-color photosensitive member drive transmission member 130Y, an M-color photosensitive member drive transmission member 130M, and a C-color photosensitive member drive transmission member 130C. Yes. Each color photoconductor drive transmission member 130Y, 130M, 130C has a photoconductor gear portion 130a, a development output gear portion 130b, and a shaft portion 130c. The distal end of the shaft portion 130c is formed with external teeth and is a spline shaft.

  The photoconductor gear portions 130a for the respective colors are disposed between the bracket 9 and the back side plate 10 facing the process unit side surface of the bracket 9. The photoconductor gear portion of the C-color photoconductor drive transmission member 130C and the photoconductor gear portion of the M-color photoconductor drive transmission member 130M are engaged with the motor gear 2 of the color motor 1. Further, the photoconductor gear portion of the M-color photoconductor drive transmission member 130M and the photoconductor gear portion of the Y-color photoconductor drive transmission member 130Y mesh with the idler gear 11.

  The developing gears 51Y, 51M, and 51C are engaged with the developing output gear portions 130b of the photosensitive member drive transmission members 130Y, 130M, and 130C for the respective colors. The developing gears 51Y, 51M, and 51C for the respective colors are rotatably supported on the outer peripheral surfaces of cylindrical metal bearing members 54Y, 54M, and 54C fixed to the back side plate 10. Further, development output shafts 53Y, 53M, 53C extending from the drive side development joints 52Y, 52M, 52C are rotatably supported on the inner peripheral surfaces of the bearing members 54Y, 54M, 54C.

  The electromagnetic clutches 7Y, 7M, and 7C are attached to the development output shafts 53Y, 53M, and 53C, and are engaged with the development gears 51Y, 51M, and 51C from the axial direction. The drive side development joints 52Y, 52M, and 52C as second drive output members integral with the development output shafts 53Y, 53M, and 53C have a cylindrical shape, and have internal teeth on the inner peripheral surface.

FIG. 16 is a schematic cross-sectional view illustrating the color driving device and the C, M, and Y color process units according to the second embodiment.
Since the drive transmission mechanism on each process unit side has the same configuration, the C color process unit will be described here, and the color code will be omitted.
A driven side photoconductor joint 124 into which a spline shaft formed at the tip of the shaft portion 130c is inserted is provided at the back end of the photoconductor drum 24. The driven-side photoreceptor joint 124 has a cylindrical shape and has inner teeth formed on the inner peripheral surface. The driven photoconductor joint 124 is rotatably supported by the case 126 of the process unit via a bearing. By inserting the spline shaft formed at the tip of the shaft portion 130c into the driven side photoconductor joint 124, the external teeth of the spline shaft and the internal teeth of the driven side photoconductor joint 124 are engaged, and the photoconductor drum 24 is implemented. Drive-coupled to the color driving device of Example 2.

  Further, a driven side developing gear 180 in which a driven gear portion 180b and a driven side developing joint portion 180a are integrally formed is provided at the back end portion of the toner supply roller 80 of the developing device 23. A developing roller gear 181 is provided at the back end of the developing roller 81, and the developing roller gear 181 meshes with the driven gear portion 180b via the developing idler gear 182. The driven side developing joint 180a is a spline shaft. By inserting the driven-side developing joint part 180a into the driving-side developing joint 52, the external teeth of the driven-side developing joint part 180a and the internal teeth of the driving-side developing joint 52 are engaged and drivingly connected.

FIG. 17 shows a drive transmission path to the M color photosensitive drum 24M and a drive path to the rotating body (developing roller and toner supply roller) of the M color developing device in the color driving device 210 of the second embodiment. It is a figure explaining about.
FIG. 17A shows a drive transmission path when the electromagnetic clutch is OFF, and FIG. 17B shows a drive transmission path when the electromagnetic clutch is ON.
As shown in FIGS. 17A and 17B, the drive transmission path from the motor gear 2 to the photoreceptor gear portion 130a of the photoreceptor drive transmission member 130M is a first drive transmission path to the photoreceptor drum 24. The drive transmission path to the rotating body of the developing device, which is the second drive transmission path, is a common drive transmission path. Then, the development output gear portion 130b of the photosensitive member drive transmission member 130M is divided into a drive transmission path for transmitting the driving force to the photosensitive drum and a drive transmission path for transmitting the driving force to the rotating body of the developing device.

  When the color motor 1 is rotationally driven, the driving force is transmitted to the photosensitive member gear portion 130a of the photosensitive member drive transmission member 130M via the motor gear 2, and the photosensitive member drive transmission member 130M is rotationally driven. When the photosensitive member drive transmission member 130 is rotationally driven, a driving force is transmitted to the driven side photosensitive member joint connected to the shaft portion 130c of the photosensitive member drive transmission member 130M, and the photosensitive drum 24M is rotationally driven. Further, the driving force is transmitted to the developing gear 51M that meshes with the developing output gear portion 130b of the photosensitive member driving transmission member 130M.

  As shown in FIG. 17A, when the electromagnetic clutch 7M is OFF, the development gear 51M idles with respect to the development output shaft 53, and no driving force is transmitted from the development gear 51M to the development output shaft 53M. As a result, the rotating body (developing roller and toner supply roller) of the M color developing device does not rotate.

  On the other hand, as shown in FIG. 17B, when the electromagnetic clutch 7M is ON, the driving force is transmitted from the developing gear 51M to the developing output shaft 53M via the electromagnetic clutch 7M, and the developing output shaft 53M is rotationally driven. . Then, as shown in FIG. 16, the driving force is transmitted to the driven side developing joint portion 180a connected to the driving side developing joint 52M, and the toner supply roller 80 is rotationally driven. Further, the driving force of the color motor is transmitted to the developing roller 81Y through the driven gear portion 180b, the developing idler gear 182, and the developing roller gear 181, and the developing roller 81Y is rotationally driven.

  Similarly, for C color, the driving force is transmitted from the motor gear 2 to the photosensitive member gear portion 130a of the photosensitive member driving transmission member 130M. Thereafter, in the same manner as described above, the driving force is transmitted, and the photosensitive drum 24C and the rotating body of the developing device 23C are rotationally driven. The Y color photosensitive drum 24Y and the rotating body of the developing device 23Y are connected to the color motor 1 via the motor gear 2, the M color photosensitive member drive transmission member 130M, and the idler gear 11 to the Y color photosensitive member drive transmission member 130Y. The driving force is transmitted. Thereafter, similarly, drive transmission is performed to the Y-color photosensitive drum 24Y and each rotating body of the Y-color developing device 23Y.

  Also in the second embodiment, the color motor drums 24Y, 24M, and 24C and the color developing devices 23Y, 23M, and 23C rotating bodies (toner supply rollers and developing rollers) are driven by the color motor 1. Therefore, the number of parts is reduced as compared with a drive motor for driving the color photosensitive drums 24Y, 24M, and 24C and a drive motor for driving the rotating bodies of the color developing devices 23Y, 23M, and 23C. it can. Thereby, the cost of the apparatus can be reduced. In addition, the apparatus can be reduced in size. Further, since the color photoconductor drums 24Y, 24M, and 24C and the rotating bodies of the color developing devices 23Y, 23M, and 23C are driven by a single motor, it is possible to reduce motor noise, motor gear meshing noise, and the like. it can. Thereby, the silence of the apparatus can be achieved.

  Also in the second embodiment, the electromagnetic clutches 7Y, 7M, and 7C are arranged in the drive transmission path for driving the rotating body (toner supply roller and developing roller) of the developing device. Therefore, even when the photosensitive drum needs to be rotated, the electromagnetic clutches 7Y, 7M, and 7C can be turned off to stop the driving of the color developing devices 23Y, 23M, and 23C. Thereby, it is possible to prevent the developing device from reaching the end of its life early.

  In the second embodiment, the electromagnetic clutch 7 is attached to the development output shaft 53 that is coaxial with the drive side development joint 52M that is a second drive output member that outputs a driving force to the developing device. Even when the electromagnetic clutch 7 is attached to the development output shaft 53, the drive transmission path to the photosensitive member and the drive transmission path to the developing device can be made common until halfway as in the first embodiment. Thereby, the driving force of the color motor can be transmitted to the photosensitive drum and the developing device by reducing the number of gears.

  In the second embodiment, the development output shaft 53 is provided with an electromagnetic clutch so that the photosensitive member gear, the development output gear, and the shaft for outputting the driving force to the photosensitive drum are integrated with each other. , 130M, 130C can be used. Thereby, the number of parts can be reduced. In addition, the photosensitive drum drive transmission members 130Y, 130M, and 130C can be assembled to the bracket 9 so as to be freely rotatable, and the assemblability can be improved.

  In general, it is required that the rotating body (developing roller and supply roller) of the developing device rotate at a higher speed than the photosensitive drum. Therefore, the drive transmission from the development output gear portion 130b to the development gear 51 is increased, and the rotation speed of the development gear is higher than that of the photosensitive member drive transmission member, and the torque is reduced. As described above with reference to FIG. 5, the electromagnetic clutch attracts the relatively rotating armature 7b to the rotor portion 7c with a magnetic force, and transmits drive between the armature 7b and the rotor portion 7c. Is. Therefore, if the electromagnetic force is weak with respect to the torque at the time of this adsorption, the armature 7b slides relative to the rotor portion 7c, and drive transmission cannot be performed correctly. Therefore, as an electromagnetic clutch to be used, it is necessary to increase the electromagnetic force according to the load torque applied to the electromagnetic clutch. The stronger the electromagnetic force can be generated, the larger the electromagnetic clutch and the higher the cost. Therefore, it is better to provide an electromagnetic clutch on the development output shaft, which is the shaft that outputs the driving force to the developing device, rather than providing an electromagnetic clutch on the shaft that outputs the driving force to the photosensitive drum 24 as in the first embodiment. The load torque applied to the electromagnetic clutch can be reduced. As a result, it is possible to use a small and inexpensive electromagnetic clutch rather than providing an electromagnetic clutch on the shaft that outputs the driving force to the photosensitive drum 24. Thereby, it is possible to reduce the size of the device and to suppress an increase in the cost of the device.

  The development output shaft 53 and the drive side development joint 52 are integrally molded resin, and the development gear 51 provided on the development output shaft 53 is also a resin molded product. When the developing gear 51 is directly supported on the developing output shaft 53 so as to be freely rotatable, the resin comes into contact with each other. The surface of the resin is difficult to process compared to the metal, and the smoothness of the resin surface is inferior to the metal. Therefore, when the developing gear 51 is directly supported on the developing output shaft 53 so as to be freely rotatable, the sliding resistance becomes higher than that when the developing gear 51 is rotatably supported on the metal surface. Therefore, in the second embodiment, the developing gear 51 is rotatably supported on the outer peripheral surface of the metal bearing member 54Y that receives the developing output shaft. Thereby, compared with the case where the development gear 51 is rotatably supported by the resin development output shaft 53, the sliding resistance is reduced, and the wear of the development gear can be suppressed. In addition, the number of parts can be reduced and the apparatus can be made cheaper compared to the case where a metal member that rotatably supports the developing gear and a bearing member that receives the developing output shaft 53 are separately provided. Can do.

  In the second embodiment, drive transmission from the photosensitive member drive transmission member to the drive side development joint 52 is performed by meshing the development output gear portion 130 b and the development gear 51. Thereby, durability can be improved compared with the case where drive transmission is performed by a belt.

  Next, a modification of the second embodiment will be described.

[Modification A]
FIG. 18 is a schematic configuration diagram of a color driving device 210A of Modification A which is a first modification of Embodiment 2.
In the color driving device 210A of Modification A, belt transmission is used for driving transmission from the photosensitive member driving transmission members 130Y, 130C, and 130M to the driving-side developing joints 52Y, 52M, and 52C. Specifically, the development output gear portion 130b of the photosensitive member drive transmission members 130Y, 130M, and 130C of Example 2 is changed to the development output pulley portion 130d, and the development gears 51Y, 51C, and 51M are changed to the development pulleys 56Y and 56M. , 56C. Timing belts 55Y, 55M, and 55C are stretched between the development output pulley portion 130d of the photoreceptor drive transmission members 130Y, 130M, and 130C and the development pulleys 56Y, 56M, and 56C.

  The electromagnetic clutches 7Y, 7M, and 7C generate an impact when switching from ON to OFF or when switching from OFF to ON, and the impact becomes vibration. In this modified example A, the timing belts 55Y, 55M, and 55C stretched between the development output pulley portion 130d of the photosensitive member drive transmission members 130Y, 130M, and 130C and the development pulleys 56Y, 56M, and 56C are elastically deformed, The vibration generated when the electromagnetic clutch is switched on / off can be absorbed. As a result, it is possible to suppress the photosensitive member drive transmission members 130Y, 130M, and 130C from vibrating due to the influence of vibration during ON / OFF switching of the electromagnetic clutch, as compared with the second embodiment. As a result, it is possible to suppress propagation of the photosensitive drum drive transmission members 130Y, 130M, and 130C to the photosensitive drum and vibration of the photosensitive drum, and it is possible to suppress occurrence of an abnormal image such as a shock jitter. .

  Further, the timing belts 55Y, 55M, and 55C can absorb and absorb the rotation unevenness of the rotating body of the developing device, and the influence of the rotation unevenness of the rotating body of the developing device is affected by the photosensitive member drive transmission members 130Y and 130M. , 130C can also be suppressed.

[Modification B]
FIG. 19 is a schematic configuration diagram of a color driving device 210B according to Modification B, which is a second modification of Embodiment 2.
In the color driving device 210B of the modified example B, the development output gear portions of the photosensitive member drive transmission members 130Y, 130M, and 130C are internal teeth 130e. In the modified example B, the driving side development joints 52Y, 52M, and 52C are separated from the development output shafts 53Y, 53M, and 53C, and are rotatably supported on the development output shafts 53Y, 53M, and 53C. Further, the developing gears 51Y, 51M, 51C are attached to the developing output shafts 53Y, 53M, 53C so as to rotate integrally with the developing output shafts 53Y, 53M, 53C. The electromagnetic clutches 7Y, 7M, and 7C are engaged with the drive side developing joints 52Y, 52M, and 52C from the axial direction.

  In this modified example B, drive is transmitted from the inner teeth 130e of the photoreceptor drive transmission members 130Y, 130M, and 130C to the development gears 51Y, 51M, and 51C, and the development output shafts 53Y, 53M, and 53C are rotationally driven. When the electromagnetic clutch is OFF, drive transmission from the development output shaft to the drive side development joint is interrupted, and the rotating body (developing roller and supply roller) of the developing device is in a rotation stopped state. When the electromagnetic clutch is ON, a driving force is transmitted from the development output shaft to the driving side development joint via the electromagnetic clutch, and the rotating body of the developing device is rotationally driven.

  In this modified example B, the development output gear portion is an internal tooth, whereby the meshing rate with the development gear 51 is improved, and vibration and noise can be suppressed. Further, the meshing portion with the developing gear 51 can be covered, and the meshing noise can be shielded by the internal teeth 130e. Moreover, since the back side of the internal tooth 130e is closed, it is possible to suppress the meshing noise from leaking to the outside. As a result, the device can be made quieter than the color driving device 210B of the second embodiment.

  Further, by making the development output gear portion an internal tooth, as shown in FIG. 19, the photosensitive member gear portion 130a, the development output gear portion, and the development gear 51 are arranged at the same position in the axial direction. Can do. As a result, it is possible to reduce the size in the axial direction as compared with the color driving device of the second embodiment shown in FIG.

  Further, as can be seen from the comparison between FIG. 15 and FIG. 19, the diameter of the development output gear portion can be increased as compared with the case where the development output gear portion has external teeth. As a result, the number of teeth of the development output gear portion can be increased, and a high speed increase ratio can be obtained by meshing the development gear portion and the development gear.

[Modification C]
FIG. 20 is a schematic configuration diagram of a color driving device 210 </ b> C according to a modification C which is a third modification of the second embodiment.
In the third modification, a cover member 140 that covers the drive transmission member on the photosensitive drum side with respect to the back side plate 10 of the color driving device is provided. By covering with the cover member 140, it is possible to prevent foreign matter from entering the color driving device 210. The cover member 140 is screwed to the back side plate 10 with screws 141.

  Further, the development output shafts 53Y, 53M, 53C integral with the drive side development joints 52Y, 52M, 52C are only supported rotatably on the inner periphery of the bearing members 54Y, 54M, 54C. Therefore, when a force is applied in the direction of the developing device to the drive side developing joints 52Y, 52M, 52C and the electromagnetic clutches attached to the developing output shafts 53Y, 53M, 53C, the developing output shafts 53Y, 53M, 53C are the bearing members. There was a risk of detachment from 54Y, 54M, and 54C. In the modified example C, the electromagnetic clutch and the driving side development joints 52Y, 52M, and 52C are covered by the cover member 140, so that it is possible to prevent the objects from touching them. As a result, the development output shafts 53Y, 53M, and 53C can be prevented from being detached from the bearing members 54Y, 54M, and 54.

  Further, in this modified example C, the retaining projections 152Y, 152M, and 152C that prevent the developing output shafts 53Y, 53M, and 53C from coming off the bearing members 54Y, 54M, and 54C by striking the cover member 140 are provided on the driving side. It is provided on the outer peripheral surface of the developing joints 52Y, 52M, 52C. Thereby, it is possible to prevent the development output shafts 53Y, 53M, and 53C from coming off the bearing members 54Y, 54M, and 54C.

[Modification D]
FIG. 21 is a schematic perspective view of a color driving device 210D of Modification D, which is a fourth modification of Embodiment 2.
In the color driving device 210D of the modified example D, the motor idler gear 13 is provided between the motor gear 2 and the photosensitive member gear portion, similarly to the color driving device 110B of the modified example 2 shown in FIG. Is.

  In the modified example D as well, as in the modified example 2, the color motor 1 is mounted even if the distance between the axes of the photosensitive drums 24 of the respective colors is smaller than the width of the motor substrate or the mounting member of the colored motor 1. The photosensitive member gear unit and the photosensitive drum can be disposed. Therefore, the apparatus can be reduced in size. Further, the meshing with the first-stage motor gear can be made one, and noise can be suppressed as compared with the configuration in which the two photoconductor gear portions are meshed with the first-stage motor gear.

  In the modification D, the motor idler gear 13 is an internal gear. Therefore, the meshing rate with the motor gear 2 can be improved and vibration and noise can be suppressed as in the third modification shown in FIG. Further, the meshing portion with the motor gear 2 can be covered with the internal gear, and the meshing noise can be shielded with the internal gear. Moreover, since the back side of the internal gear is closed, it is possible to suppress the meshing noise from leaking outside. Thereby, the silence of the apparatus can be achieved.

[Modification E]
FIG. 22 is a schematic configuration diagram of a color driving device 210E of Modification E, which is a fifth modification of Embodiment 2.
In the color driving device 210E of Modification E, cylindrical boss portions 151Y, 151M, and 151C are provided on the developing gears 51Y, 51M, and 51C. And these boss | hub parts 151Y, 151M, and 151C are inserted in the hole 10a of the back side board 10, and the developing gear 51Y, 51M, 51C is rotatably supported by the back side board 10. FIG. The development output shafts 53Y, 53M, and 53C are rotatably received by the boss portions 151Y, 151M, and 151C, and are rotatably supported by the back side plate 10.

  In this modification E, the bearing members 54Y, 54M, and 54C can be eliminated, the number of parts can be reduced, and the cost of the apparatus can be reduced.

  Further, as the basic configuration of the black driving device that rotationally drives the rotating body (the developing roller 81 and the toner supply roller 80) of the K photosensitive drum 24K and the developing device 23K, the first embodiment and the first to fourth modifications described above. The configuration of can be adopted. That is, it has a drive motor and a photoconductor gear that meshes with the motor gear of the drive motor. In addition, an electromagnetic clutch, a development output gear, and a drive side photoreceptor joint are attached to a rotating shaft to which the photoreceptor gear is fixed. In addition, a driving side developing gear having a developing gear portion meshing with the developing output gear and a driving side developing joint portion is rotatably supported by a support shaft provided on the back side plate 10.

  Further, as the basic configuration of the black driving device that rotationally drives the rotating body (the developing roller 81 and the toner supply roller 80) of the K photosensitive drum 24K and the developing device 23K, the above-described second embodiment and modifications A to E are described. The configuration of can also be adopted. That is, a photoconductor drive having a drive motor, a motor gear and a photoconductor gear portion of the drive motor, a development output gear portion that transmits a drive force to the rotating body of the developing device, and a shaft portion that transmits the drive force to the photoconductor drum. And a transmission member. Further, an electromagnetic clutch and a developing gear that meshes with the developing output gear portion are provided coaxially with the driving side developing joint that outputs driving force to the developing device.

What was demonstrated above is an example, and there exists an effect peculiar for every following aspect.
(Aspect 1)
A drive capable of switching between a drive motor, a first drive transmission path for transmitting the drive force of the drive motor to the first rotating body, and a state for transmitting the drive force of the drive motor and a state for interrupting transmission of the drive force A drive device having a transmission switching means and a second drive transmission path for transmitting the driving force to the second rotating body, wherein the drive transmission switching means is provided in the first drive transmission path. The rotating shaft that rotates integrally with the member was provided.

  In the drive device described in Patent Document 1, a drive transmission member such as a photosensitive gear of a first drive transmission path and an input gear of a drive transmission switching unit such as a clutch of a second drive transmission path are engaged with a motor gear of a drive motor. Thus, the drive transmission path is divided into a first drive transmission path and a second drive transmission path at the motor gear. In such a configuration, when the second rotating body such as the developing roller is provided on the opposite side of the motor gear across a rotating shaft such as a shaft that rotates integrally with a drive transmission member such as a photoconductor gear. The drive transmission switching means is arranged as follows. That is, in order to mesh the input gear of the drive transmission switching means with the motor gear, the drive transmission switching means is disposed on the opposite side of the second rotating body with the rotation shaft interposed therebetween. As a result, the rotation shaft is obstructed, and the output gear of the drive transmission switching means cannot directly mesh with the most downstream gear of the second drive transmission path such as the developing gear. Therefore, an idler gear is provided, and the drive transmission is performed between the output gear and the most downstream gear of the second drive transmission path via the idler gear.

  In contrast, in the first aspect, the drive transmission switching means such as the electromagnetic clutch is provided on the rotating shaft that rotates integrally with the drive transmission member such as the photoconductor gear provided in the first drive transmission path. Thus, from the motor gear to the rotation shaft, the first drive transmission path and the second drive transmission path are a common drive transmission path, and the first drive transmission path and the second drive transmission path branch at the rotation axis. It becomes composition. By adopting such a configuration, even if the second rotating body is provided on the opposite side across the motor gear and the rotating shaft of the drive motor, the second drive can be performed from the drive transmission switching means without the idler gear. It becomes possible to transmit the driving force directly to the most downstream gear (the developing gear portion 8a in the present embodiment) of the transmission path. Thus, unlike the drive device described in Patent Document 1, no idler gear is required, the number of parts can be reduced, and the cost of the device can be reduced. Further, it is possible to reduce the size of the drive device as compared with the drive device described in Patent Document 1.

(Aspect 2)
A driving motor such as the color motor 1, a first drive transmission path for transmitting the driving force of the driving motor to the first rotating body such as the photosensitive drum 24, and a state and driving for transmitting the driving force of the driving motor 1 A drive device having a drive transmission switching means such as an electromagnetic clutch capable of switching between a state where force transmission is cut off and a second drive transmission path for transmitting the drive force to a second rotating body such as a developing roller The drive transmission switching means is provided coaxially with a second drive output member such as a drive side development joint 52 that outputs the drive force to a unit such as the developing device 23 provided with the second rotator.

  Also in this aspect 2, as in the first aspect, the first drive transmission path and the second drive transmission path are common drive transmission paths from the motor gear to the rotation shaft such as the shaft portion 130c. The drive transmission path and the second drive transmission path can be branched. By adopting such a configuration, even if the second rotating body is provided on the opposite side across the motor gear and the rotating shaft of the drive motor, the most downstream stage of the second drive transmission path is not provided via the idler gear. The driving force can be transmitted to the gear (the developing gear in the second embodiment). Thus, unlike the drive device described in Patent Document 1, no idler gear is required, the number of parts can be reduced, and the cost of the device can be reduced. Further, it is possible to reduce the size of the drive device as compared with the drive device described in Patent Document 1.

(Aspect 3)
In (Aspect 2), the driving force is provided via a drive transmission member that is provided coaxially with the second drive output member such as the drive-side development joint 52 and that constitutes the first drive transmission path such as the photosensitive member drive transmission member 130. The second drive transmission member such as the developing gear 51 to be transmitted is rotatably supported on the outer peripheral surface, and the rotation shaft such as the development output shaft 53 to which the second drive output member is attached is rotatable on the inner peripheral surface. A bearing member 54 is provided.
According to this, as described in the second embodiment, the member that rotatably supports the second drive transmission member such as the developing gear 51 and the rotating shaft such as the developing output shaft 53 are rotatably received on the inner peripheral surface. The number of parts can be reduced and the cost of the apparatus can be reduced as compared with the case where each member is provided.

(Aspect 4)
In any one of (Aspect 1) to (Aspect 3), the second drive transmission member such as the development gear 51 provided coaxially with the second drive output member such as the drive side development joint 52 is the first drive transmission path. The driving force is transmitted through a drive transmission member such as the photosensitive member drive transmission member 130 constituting the.
According to this, a branch is made from a drive transmission member such as the photosensitive member drive transmission member 130 constituting the first drive transmission path to the second drive transmission path. Thus, unlike the case where the drive transmission path is divided into the first drive transmission path and the second drive transmission path at the motor gear, the second rotating body is provided on the opposite side across the motor gear and the rotation shaft of the drive motor. Even with such a configuration, the idler gear is not required, the number of parts can be reduced, and the cost of the apparatus can be reduced. Further, it is possible to reduce the size of the drive device as compared with the drive device described in Patent Document 1.

(Aspect 5)
In any one of (Aspect 1) to (Aspect 4), the second drive transmission path has a gear train.
According to this, as described in the second embodiment, the durability can be improved as compared with the case where drive transmission is performed by a belt.

(Aspect 6)
In (Aspect 5), the second drive transmission path such as the drive transmission path to the developing roller has an internal gear.
According to this, as described in the modified example B, vibration and noise can be suppressed as compared with the case where the second drive transmission path is configured only by the external gear. Further, the meshing portion with the internal gear can be covered with the internal gear, and the meshing noise can be shielded by the internal gear. Thereby, compared with the case where a 2nd drive transmission path is comprised only with an external gear, the noise reduction of an apparatus can be achieved.

(Aspect 7)
In (Aspect 4), the second drive transmission path includes a belt drive transmission unit.
According to this, as described in the modification example A, the vibration at the time of switching the drive transmission of the drive transmission switching means such as the electromagnetic clutch can be absorbed by the elastic deformation of the belt member of the belt drive transmission unit. Thereby, it is possible to suppress the influence of vibration at the time of the drive transmission switching of the drive transmission switching means from reaching the first rotating body such as the photosensitive drum 24.

(Aspect 8)
In any one of (Aspect 1) to (Aspect 7), the second rotating body such as the developing roller 81 is stopped at a predetermined timing while the first rotating body such as the photosensitive drum 24 is rotating.
According to this, by switching from the state in which the driving force is transmitted by the drive transmission switching means such as the electromagnetic clutch 7 to the state in which the transmission of the driving force is interrupted, the two-rotor such as the developing roller 81 is changed to the photosensitive drum 24 or the like. The rotation can be stopped during the rotation of the first rotating body. Thereby, the lifetime of a 2nd rotary body can be extended.

(Aspect 9)
In any one of (Aspect 1) to (Aspect 8), the first rotating body is a photosensitive body such as the photosensitive drum 24, and the second rotating body is the developing roller 81.
As described in the embodiment, the developing roller 81 has a shorter life than a photoconductor such as the photoconductor drum 24, but since the rotation of the developing roller can be stopped at a predetermined timing during the rotation of the photoconductor, The life of the roller can be extended.

(Aspect 10)
In any one of (Aspect 1) to (Aspect 9), the teeth of the motor gear 2 provided on the motor shaft of a drive motor such as the color motor 1 are arranged so that the tip end side of the motor shaft is in a normal rotating operation of the motor shaft. The helical teeth were twisted so as to be located downstream in the rotation direction.
The “normal rotation operation time” refers to the rotation direction with the longer rotation time in a predetermined period, and in this embodiment, the image forming operation corresponds to the normal rotation operation time.
According to this, as described in the third modification, the motor gear 2 receives a thrust force toward the tip end side of the motor shaft. As a result, the drive motor such as the color motor 1 having the motor gear is pressed against the motor mounting surface to which the drive motor such as the bracket 9 or the back side plate 10 is mounted. As a result, at the time of driving, the posture of the driving motor can be stabilized, and uneven rotation can be suppressed. Further, it is possible to suppress the vibration of the drive motor and reduce the noise of the motor.

(Aspect 11)
In any one of (Aspect 1) to (Aspect 10), an internal gear 13A that meshes with the motor gear 2 of the drive motor such as the color motor 1 is provided, and the drive transmission member such as the photosensitive gear 3 is an outer periphery of the internal gear 13A. A gear that meshes with an external tooth portion provided on the surface.
According to this, as described in Modification 3 and Modification D, the meshing rate with the motor gear 2 can be improved, and vibration and noise can be suppressed. Further, the meshing portion with the motor gear 2 can be covered with the internal gear 13A, and the meshing noise can be shielded with the internal gear 13A. Further, the reduction ratio can be increased by suppressing the size in the radial direction as compared with the external gear, and the device can be downsized as compared with the external gear.

(Aspect 12)
In any one of (Aspect 1) to (Aspect 11), the internal tooth portion of the internal gear and the external tooth portion are helical teeth having the same twist direction.
According to this, as described in the third modification, the direction of the thrust force received by the internal gear portion of the internal gear and the direction of the thrust force received by the external gear portion of the internal gear can be made opposite to each other. Thereby, the thrust force of the internal gear portion of the internal gear can be canceled by the thrust force of the external gear portion, and the internal gear can be prevented from moving in any one of the axial directions. Thereby, it can suppress that an internal gear contacts the back side board 10 and the bracket 9. FIG.

(Aspect 13)
In any one of (Aspect 1) to (Aspect 12), the drive motor such as the color motor 1 is connected to the drive transmission member such as the photoconductor gear 3 in the axial direction of the first rotary body such as the photoconductor drum 24 and the first. Arranged between the rotating body.
According to this, as described in Modification 1 and Modification D, the drive device can be reduced in size in the axial direction.

(Aspect 14)
In any one of (Aspect 1) to (Aspect 13), the drive transmission member such as the photoconductor gear 3 and the drive transmission switching unit that transmits the driving force from the drive transmission switching unit such as the electromagnetic clutch 7 are arranged coaxially. The drive output member such as the development output gear 6 is a helical gear having the same twisting direction.
According to this, as described in the third modification, the direction of the thrust force received by the drive transmission member such as the photoconductor gear 3 is opposite to the direction of the thrust force received by the drive output member such as the development output gear 6. Direction and cancel out the thrust force. Thereby, when the drive transmission switching means such as the electromagnetic clutch 7 is in a state of transmitting the driving force of the drive motor, it is possible to suppress the rotation shaft from moving in any one of the axial directions. As a result, when the drive transmission switching means such as the electromagnetic clutch 7 is in a state of transmitting the driving force of the drive motor, the photosensitive gear fixed to the rotating shaft moves together with the rotating shaft, and the back side plate 10 And the contact with the bracket 9 can be suppressed.

(Aspect 15)
In any one of (Aspect 1) to (Aspect 14), the drive transmission member such as the photoconductor gear 3 and the drive transmission switching unit that transmits the driving force from the drive transmission switching unit such as the electromagnetic clutch 7 are arranged coaxially. The drive output member such as the development output gear 6 is disposed on the first rotating body side such as the photosensitive drum 24 with respect to the drive transmission switching means.
According to this, as described in the fourth modification, the drive transmission member such as the electromagnetic clutch 7 and the like without removing the drive transmission member such as the photoconductor gear 3 and the drive output member such as the development output gear 6 from the rotary shaft 17. The switching means can be removed from the rotating shaft 17, and the drive transmission switching means can be easily replaced.

(Aspect 16)
In any one of (Aspect 1) to (Aspect 15), the drive transmission switching means is an electromagnetic clutch.
According to this, the driving force can be transmitted by turning on the electromagnetic clutch, and the driving force can be blocked by turning off the electromagnetic clutch.

(Aspect 17)
A developing device 23 having a photosensitive member such as the photosensitive drum 24, a developing roller 81, and developing a latent image formed on the surface of the photosensitive member, and a driving device for driving the photosensitive member and the developing roller. In the image forming apparatus having the above, any one of the driving devices (Aspect 1) to (Aspect 16) is provided as the driving device.
According to this, it is possible to reduce the cost of the image forming apparatus and to reduce the size of the image forming apparatus.

(Aspect 18)
In (Aspect 17), a latent image forming apparatus such as a charging device 25 that uniformly charges the surface of a photosensitive member such as the photosensitive drum 24 and an optical writing unit 27 that forms an electrostatic latent image on the surface of the photosensitive member. And a transfer device such as a primary transfer roller 74 for transferring an image formed on the surface of the photoconductor to a transfer body such as the intermediate transfer belt 22, wherein the first rotating body is the photoconductor, and the second The rotating body is the developing roller, and the drive transmission switching means such as an electromagnetic clutch switches from a state in which the transmission of the driving force is cut off to a state in which the driving force is transmitted before the latent image forming apparatus starts the latent image formation. Then, after the image transfer by the transfer device is finished, the state is switched from the state of transmitting the driving force to the state of interrupting the transmission of the driving force.
According to this, as described with reference to FIG. 14, it is possible to suppress the occurrence of an abnormal image such as a shock jitter due to the influence of the impact when the transmission state is switched by the drive transmission switching means such as the electromagnetic clutch 7.

1: Color motor (drive motor)
1a: motor board 1b: mounting member 2: motor gear 3: photoconductor gear 6: development output gear 7: electromagnetic clutch (drive transmission switching means)
8: Driving side developing gear 8a: Developing gear portion 8b: Driving side developing joint portion 9: Bracket 9a: Hole 10: Back side plate 11: Idler gear 13: Motor idler gear 13A: Internal gear 15: Cap member 17: Rotation Shaft 22: Intermediate transfer belt (transfer body)
23: Developing device 24: Photosensitive drum (photosensitive member)
25: Charging device 26: Process unit 27: Optical writing unit 51: Development gear 52: Driving side development joint 53: Development output shaft 54: Bearing member 55: Timing belt 56: Development pulley 74: Primary transfer roller (transfer device)
80: Toner supply roller 81: Developing roller 110: Color driving device 110A: Color driving device 110B of Modification 1 Color driving device 110C of Modification 2 Color driving device 110D of Modification 3 Modification 4 Color driving device 112: driving side photoconductor joint 124: driven side photoconductor joint 130: photoconductor driving transmission member 130a: photoconductor gear portion 130b: development output gear portion 130c: shaft portion 130d: development output pulley portion 140: Cover member 151: Boss portion 152: Retaining prevention projection 180: Driven side developing gear 180a: Driven side developing joint portion 180b: Driven gear portion 181: Developing roller gear

JP 2012-208458 A

Claims (18)

A drive motor;
A first drive transmission path for transmitting the driving force of the drive motor to the first rotating body;
Drive transmission switching means capable of switching between a state of transmitting the driving force of the driving motor and a state of interrupting the transmission of the driving force, and a second drive transmission path for transmitting the driving force to the second rotating body In the drive device provided,
The drive device according to claim 1, wherein the drive transmission switching means is provided on a rotary shaft that rotates integrally with a drive transmission member constituting the first drive transmission path. A drive motor;
A first drive transmission path for transmitting the driving force of the drive motor to the first rotating body;
Drive transmission switching means capable of switching between a state of transmitting the driving force of the driving motor and a state of interrupting the transmission of the driving force, and a second drive transmission path for transmitting the driving force to the second rotating body In the drive device provided,
The drive device characterized in that the drive transmission switching means is provided coaxially with a second drive output member that outputs the drive force to a unit including the second rotating body. The drive device according to claim 2, wherein
A second drive transmission member that is provided coaxially with the second drive output member and through which the drive force is transmitted via the drive transmission member constituting the first drive transmission path is rotatably supported on the outer peripheral surface, A drive apparatus comprising a bearing member that rotatably receives on its inner peripheral surface a rotation shaft to which the second drive output member is attached. The drive device according to any one of claims 1 to 3,
The second drive transmission member provided coaxially with the second drive output member transmits a driving force via a drive transmission member constituting the first drive transmission path. The drive device according to any one of claims 1 to 4,
The second drive transmission path has a gear train. The drive device according to claim 5, wherein
The drive device characterized in that the second drive transmission path has an internal gear. The drive device according to claim 4, wherein
The second drive transmission path includes a belt drive transmission unit. The drive device according to any one of claims 1 to 7,
The second rotating body stops at a predetermined timing during the rotation of the first rotating body. The drive device according to any one of claims 1 to 8,
The driving device according to claim 1, wherein the first rotating body is a photoconductor, and the second rotating body is a developing roller. The drive device according to any one of claims 1 to 9,
The tooth of the motor gear provided on the motor shaft of the drive motor is a helical tooth that is twisted so that the tip side of the motor shaft is located downstream in the rotation direction during normal rotation operation of the motor shaft. A drive device characterized by the above. The drive device according to any one of claims 1 to 10,
An internal gear that meshes with the motor gear of the drive motor;
The drive device, wherein the drive transmission member is a gear that meshes with an external tooth portion provided on an outer peripheral surface of the internal gear. The drive device according to any one of claims 1 to 11,
2. A driving apparatus according to claim 1, wherein the internal gear portion of the internal gear and the external gear portion are helical teeth having the same twist direction. The drive device according to any one of claims 1 to 12,
The drive apparatus characterized by arrange | positioning the said drive motor between the said drive transmission member and said 1st rotary body in the axial direction of said 1st rotary body. The drive device according to any one of claims 4 to 13, excluding the one cited in claim 1, claim 2 or 3.
The drive transmission member, the drive transmission switching means for transmitting a driving force from the drive transmission switching means, and the drive output member arranged coaxially are helical gears having the same twist direction. A drive device. 15. The driving device according to any one of claims 4 to 14, excluding the one cited in claim 1, claim 2 or 3.
The drive transmission member, the drive transmission switching means for transmitting the driving force from the drive transmission switching means, and the drive output member arranged coaxially are arranged closer to the first rotating body than the drive transmission switching means. A drive device characterized by the above. The drive device according to any one of claims 1 to 15,
The drive device, wherein the drive transmission switching means is an electromagnetic clutch. A photoreceptor,
A developing device having a developing roller for developing a latent image formed on the surface of the photoreceptor;
In an image forming apparatus comprising a driving device for driving the photosensitive member and the developing roller,
An image forming apparatus comprising the driving device according to claim 1 as the driving device. The image forming apparatus according to claim 17.
A charging device for uniformly charging the surface of the photoreceptor;
A latent image forming apparatus for forming an electrostatic latent image on the surface of the photoreceptor;
A transfer device that transfers the image formed on the surface of the photoreceptor to a transfer body;
The first rotating body is the photosensitive body, and the second rotating body is the developing roller,
The drive transmission switching means switches from a state in which the transmission of the driving force is interrupted to a state in which the driving force is transmitted before the latent image formation by the latent image forming device starts, and after the image transfer by the transfer device is completed, An image forming apparatus that switches from a transmitting state to a state that interrupts transmission of driving force.

Images