JP6697712B2 - Drive device and image forming apparatus - Google Patents

Description

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

  The image forming apparatus is equipped with a driving device that rotationally drives a rotating body such as a photoconductor and a developing roller.

  For example, in Patent Document 1, a first drive transmission path for drivingly transmitting a driving force of a driving motor to a photoconductor as a first rotating body, and a driving force of the driving motor for driving to a developing roller as a second rotating body. A drive device with a second drive transmission path is described. The first drive transmission path that transmits 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 the joint formed on the shaft 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 has a clearance, and a developing gear meshing with the idler gear, and a joint integrally formed with the developing gear. Is equipped with. 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 the shaft portion of the photoconductor gear interposed therebetween, 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 configure the second drive transmission path, and thus has 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 that transmits the drive force of the drive motor to a first rotating body, a state and a drive force that transmit the drive force of the drive motor. In a drive device having a drive transmission switching means capable of switching between a state in which the transmission of the power is cut off, and a second drive transmission path for transmitting the driving force to the second rotating body, the drive transmission switching means includes: the set only to the first driving rotary shaft that rotates integrally with the drive transmission member constituting the transmission path, said second drive transmission path includes a gear train, and said drive transmission member, from the drive transmission switching means The drive transmission switching means for transmitting the driving force and the drive output member arranged coaxially are helical gears having the same twisting direction .

  According to the present invention, it is possible to reduce the cost of the device and reduce the size of the device.

1 is a schematic configuration diagram of a printer according to an embodiment. An enlarged explanatory view 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 a drive device for colors. (B) is the figure which looked at the driving device for colors from which the bracket and the back side board were removed from the back side. The schematic block diagram of an electromagnetic clutch. FIG. 6A is a perspective view showing an electromagnetic clutch and a development output gear. (B) is a perspective view of an electromagnetic clutch. FIG. 6C is a perspective view of the development output gear. FIG. 6 is a diagram illustrating a drive transmission path to a Y-color photosensitive drum and a drive path to a rotary body of a Y-color developing device. FIG. 8 is a schematic configuration diagram of a color drive device of Modification 1; FIG. 11 is a perspective view of a color driving device of Modification 2; FIG. 8 is a schematic configuration diagram of a color drive device of Modification 2; FIG. 10 is a schematic configuration diagram of a color drive device of Modification 3; FIG. 11 is an enlarged view of a broken line portion C shown in FIG. FIG. 11 is a schematic configuration diagram of a color drive device of Modification 4; The timing chart which shows an example of ON/OFF of a color motor and ON/OFF of an electromagnetic clutch. 6 is a schematic configuration diagram showing a color driving device of Example 2. FIG. 7 is a schematic cross-sectional view showing a color driving device and a C, M, Y color process unit of Embodiment 2. FIG. 7A and 7B are diagrams illustrating a drive transmission path to a photoconductor drum of M color and a drive path to a rotating body of a developing device of M color in the color drive device according to the second embodiment. FIG. 8 is a schematic configuration diagram of a color drive device of 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. FIG. 10 is a schematic perspective view of a color driving device of Modification D. FIG. 11 is a schematic configuration diagram of a color drive device of Modification E.

  An embodiment of an electrophotographic printer 100 as an image forming apparatus to which the present invention is applied will be described below. First, the basic configuration of the printer 100 according to this 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 K, C, M, and Y toners of different colors as image forming substances, but have the same configuration except that they are replaced at the end of their life.

  FIG. 2 is an enlarged explanatory view of one of the four process units 26K, 26C, 26M and 26Y. The four process units 26K, 26C, 26M, and 26Y are the same except that the colors of the toners used are different, so the subscripts (K, C, M, Y) indicating the colors of the toners used are omitted in FIG. is doing. As shown in FIG. 2, the process unit 26 includes a photosensitive drum unit 30 that holds a drum-shaped photosensitive drum 24 as a latent image carrier, a photosensitive member cleaning device 83, a charge eliminating device and a charging device 25, and a developing device 23. It has and. The process unit 26 as an image forming unit can be attached to and detached from the main body of the printer 100, and consumable parts can be replaced at once.

  The charging device 25 uniformly charges the surface of the photoconductor drum 24, which 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 light L emitted by 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 the developing device 23 that uses toner. Then, the image is primarily transferred onto the intermediate transfer belt 22.

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

  The developing device 23 has a vertically long hopper portion 86 that stores toner as a developer, and a developing portion 87. Inside the hopper portion 86 as a developer accommodating portion, an agitator 88 rotatably driven by a driving means, a toner supply roller 80 as a developer supplying member rotatably driven by the driving means vertically below the agitator 88, and the like are provided. Has been done. The toner in the hopper unit 86 moves toward the toner supply roller 80 by its own weight while being stirred 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 cored bar. The toner accumulated on the lower side inside the hopper 86 is transferred to the surface of the roller part. Rotate while attaching.

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

  The formation of such a toner image is performed by each process unit 26K, 26C, 26M, 26Y, and the toner image of each color is formed on the photosensitive drum 24 of each process unit 26K, 26C, 26M, 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 the laser light L emitted from the laser diode based on the 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 photoconductor drums 24, respectively. It functions as an image forming means for forming a toner image.

  The optical writing unit 27 irradiates the photoconductor 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, a unit that performs optical writing with LED light emitted from a plurality of LEDs of the LED array may be adopted.

  Below the four process units 26K, 26C, 26M, and 26Y in the vertical direction, a transfer unit 75 is disposed as a belt device for endlessly moving the endless intermediate transfer belt 22 in a counterclockwise direction in the drawing. Has been done. The transfer unit 75 includes a drive 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, etc. in addition to the intermediate transfer belt 22. Is equipped with.

  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 arranged inside the loop. It is hung. Then, it is endlessly moved in the same direction by the rotational force of the drive roller 76 which is rotationally driven in the counterclockwise direction in the drawing by the drive means.

  The four primary transfer rollers 74K, 74C, 74M, and 74Y sandwich the intermediate transfer belt 22 thus endlessly moved between the photoconductor drums 24K, 24C, 24M, and 24Y. Due to 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 come into contact are formed.

  A primary transfer bias is applied to each of 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 photoconductor 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 adopted.

  The Y-color toner image formed on the surface of the photoconductor drum 24Y of the process unit 26Y enters the above-described Y primary transfer nip as the photoconductor drum 24Y rotates. In the Y primary transfer nip, 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 the nip pressure. The intermediate transfer belt 22 on which the Y-color toner image is primarily transferred in this manner moves on the photosensitive drums 24M, 24C, and 24K when passing through the primary transfer nips for M, C, and K due to its endless movement. The M, C, and K color toner images are sequentially superposed on the Y color toner image and primarily transferred. By this primary transfer of superposition, a four-color toner image is formed on the intermediate transfer belt 22.

  The secondary transfer roller 21 of the transfer unit 75 is arranged outside the loop of the intermediate transfer belt 22 and sandwiches the intermediate transfer belt 22 with the tension roller 20 inside the loop. Due to this sandwiching, a secondary transfer nip where the front surface of the intermediate transfer belt 22 and the secondary transfer roller 21 are in contact with each other 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 which is grounded.

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

  A registration roller pair 43 composed of two registration rollers is disposed near the end of the paper feed path. The registration roller pair 43 stops the rotation of both rollers as soon as the recording paper as a recording member fed from the paper feed cassette 41 is sandwiched between the rollers. Then, the nipped recording paper is restarted to rotate at a timing such that it can be synchronized with the four-color toner image on the intermediate transfer belt 22 in the secondary transfer nip, and the recording paper is sent toward the secondary transfer nip.

  The four-color toner image on the intermediate transfer belt 22, which is brought into close contact with the recording paper at the secondary transfer nip, is secondarily transferred onto the recording paper collectively under the influence of the secondary transfer electric field and the nip pressure, and combined with the white color of the recording paper. , A full-color toner image. The recording paper on which the full-color toner image is 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, it is sent to the fixing device 40 as a fixing unit via the 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 sent into the fixing device 40 is sandwiched in the fixing nip so that its unfixed toner image bearing surface is brought into 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 ejected from inside the fixing device 40 is ejected outside the apparatus as it is. Then, it is stacked on the stack portion formed by the upper surface of the upper cover 56 of the housing.

  Incidentally, the transfer residual 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 the belt cleaning device 71 which is in contact with the front surface of the intermediate transfer belt 22. The cleaning backup roller 72 arranged 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 illustrates a color driving device C according to the first exemplary embodiment that drives the color photoconductor drums 24C, 24M, 24Y and the rotating bodies (developing roller 81 and toner supply roller 80) of the color developing devices 23Y, 23M, 23C. FIG. 7 is a schematic cross-sectional view showing process units 26C, 26M, and 26Y of M, Y colors.
Since the drive transmission mechanism on the side of each process unit has the same configuration, the process unit of C color will be described here.
A color driving device 110 is arranged on the back side of the printer, which is the downstream side in the mounting direction of the process unit. A driven-side photoconductor joint 124 connected to the drive-side photoconductor joint 112 attached to the tip of the rotary shaft 17 is provided at the rear end of the photoconductor drum 24. The driven-side photoconductor joint 124 is rotatably supported by the case 126 of the process unit via a bearing.

  A driven-side developing gear 180 including a driven gear portion 180b and a driven-side developing joint portion 180a formed integrally with each other is provided at the rear end of the toner supply roller 80 of the developing device 23. A developing roller gear 181 is provided at the rear end of the developing roller 81, and the developing roller gear 181 meshes with a driven gear portion 180b via a developing idler gear 182. The driven side developing joint portion 180a is connected to the driving side developing joint portion 8b of the driving side developing gear 8.

FIG. 4A is a schematic cross-sectional view of the color driving device 110 of the first embodiment, and FIG. 4B illustrates the color driving device of the first embodiment from which the bracket 9 and the back side plate 10 are removed from the back side. It is the figure seen.
As shown in FIG. 4A, the color driving device 110 of the first embodiment includes the color motor 1, and 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.

  A Y-color photoconductor gear 3Y, an M-color photoconductor gear 3M, a C-color photoconductor gear 3C, and an idler gear are provided between the bracket 9 and the back side plate 10 facing the process unit side surface of the bracket 9. 11 are provided. The Y-color photoconductor gear 3Y and the M-color photoconductor gear 3M mesh 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, 3C are fixed to rotating shafts 17Y, 17M, 17C rotatably supported by the bracket 9 and the rear side plate 10. Driving-side photoconductor joints 112Y, 112M, and 112c are attached to the tips of the rotary shafts 17Y, 17M, and 17C. Further, the rotary shafts 17Y, 17M, 17C are provided with electromagnetic clutches 7Y, 7M, 7C and developing output gears 6Y, 6M, 6C.

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

Next, the electromagnetic clutch will be described. Since the electromagnetic clutches of the respective colors have the same configuration, the color code will be omitted in the following description.
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, and FIG. 6C is a development output. It is a perspective view of a gear 6.
As shown in FIG. 5, the electromagnetic clutch 7, which is a 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 rotary shaft 17 is inserted, and the insertion hole has a D-shaped cross section. The rotary shaft 17 has a notch and a D-shaped cross section so as to fit with the D-shape. By fitting the section D-shaped portion of the shaft fixing portion 7e with the section D-shaped portion of the rotating shaft 17, the shaft fixing portion 7e 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. The armature 7b made of a metal disk is attached to a clutch drive transmission member 7f having a pair of drive claws 7a extending toward the developing output gear side.
As shown in FIGS. 5 and 6(c), a pair of fitting holes 6a is formed on the surface of the developing output gear 6 facing the electromagnetic clutch 7, and a clutch drive transmission member is formed in the fitting holes 6a. The drive claw 7a of 7f is fitted.

  The clutch drive transmission member 7f, which is integral with the armature 7b, has a predetermined clearance with respect to the shaft fixing portion 7e so that the armature 7b surely attracts to the rotor portion 7c by slidingly moving to the rotor portion 7c side when the clutch is ON. It is attached to the shaft fixing portion 7e. Therefore, the clutch drive transmission member 7f inevitably has a large play in the radial direction with respect to the rotation shaft. As a result, the clutch drive transmission member 7f causes a so-called axial misalignment in which the center of the rotary shaft 17 and the center of the rotary shaft of the clutch drive transmission member 7f are displaced due to their own weight or the like. When the clutch is turned on, the armature 7b of the clutch drive transmission member 7f comes into close contact with the rotor portion 7c in the state where the shaft center deviation occurs.

  When the armature 7b is attached to the development output gear 6 and the development output gear 6 is the clutch drive transmission member 7f, the following problems occur. That is, when the clutch drive transmission member 7f has an axial deviation when the clutch is ON, the meshing position between the clutch drive transmission member 7f and the developing gear portion 8a fluctuates in the radial direction. As a result, the clutch drive transmission member 7f rotates fast when the distance between the meshing position and the center of the rotary shaft 17 becomes short, and slows when the meshing position becomes far. Therefore, the developing gear portion 8a, to which the driving force is transmitted from the clutch drive transmitting member 7f, has uneven rotation speed, and the developing roller 81Y has uneven rotation speed.

  On the other hand, in the present embodiment, the developing output gear 6 is rotatably attached to the rotating shaft 17, and the developing output gear 6 is provided with a fitting hole 6a into which the driving claw 7a of the clutch drive transmission member 7f fits. The gear 6 and the electromagnetic clutch 7 are drivingly connected in the axial direction. The developing output gear 6 may be a gap rotatable with respect to the rotating shaft 17, is accurately positioned in the radial direction with respect to the rotating shaft 17, and has a center of the rotating shaft of the developing output gear 6 and a center of the rotating shaft 17. Match exactly. As a result, in the drive transmission between the developing output gear 6 and the developing gear portion 8a, it is possible to prevent the developing gear portion 8a from having uneven rotation speed.

  Further, by providing the developing output gear 6 coaxially with the electromagnetic clutch 7, even when the clutch drive transmission member 7f is misaligned with the rotating shaft 17 when the clutch is ON, the developing output gear 6 and Rotational speed unevenness does not occur 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 pawl 7a of the clutch drive transmission member 7f revolves around the shaft center of the rotary shaft 17. .. Similarly, the fitting hole 6 a of the developing output gear 6 attached to the rotary shaft 17 also revolves around the shaft center of the rotary shaft 17. In this way, since the drive pawl 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 displaced from the rotary shaft 17, the clutch drive transmission member 7f is driven. The connection position between the transmission member 7f and the development output gear 6 does not fluctuate in the radial direction. As a result, it is possible to suppress uneven rotation speed in drive transmission between the development output gear 6 and the clutch drive transmission member 7f.

FIG. 7 is a diagram illustrating a drive transmission path to the Y-color photosensitive drum and a drive path to the rotating body (developing roller and toner supply roller) of the Y-color developing device.
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 rotary shaft 17 is divided into a drive transmission path for transmitting the drive force to the photosensitive drum and a drive transmission path for transmitting the drive force to the rotary 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 photoconductor joint connected to the drive-side photoconductor joint 112Y, and the photoconductor drum 24Y is rotationally driven.

  As shown in FIG. 7A, when the electromagnetic clutch 7Y is OFF, the rotation shaft 17Y idles with respect to the development output gear 6, and the driving force is not 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 rotary shaft 17, and the driving force is transmitted to the developing output gear 6Y via the electromagnetic clutch 7 to develop the 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 via 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 the M color, the driving force is transmitted from the motor gear 2 to the photoconductor gear 3M. After that, the driving force is transmitted in the same manner as described above, and the rotating body of the photoconductor drum 24M and the developing device 23M is rotationally driven. The driving force of the color motor is transmitted to the C-color photoconductor drum 24C via the motor gear 2, the M-color photoconductor gear 3M, the idler gear 11, the C-color photoconductor gear 3C, and the driving-side photoconductor joint 112c. .. After that, drive transmission is performed in the same manner as in FIG. 7 and Y color.

  In this embodiment, the color motor 1 drives the color photoconductor 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 the case where the drive motor for driving the color photoconductor drums 24Y, 24M, 24C and the drive motor for driving the rotating bodies of the color developing devices 23Y, 23M, 23C are separately provided. it can. As a result, the cost of the device can be reduced. Further, the size of the device can be reduced.

  Further, in recent years, quietness of printers has been required more strongly than ever. As in the present embodiment, one motor drives the color photoconductor drums 24Y, 24M, 24C and the rotating bodies of the color developing devices 23Y, 23M, 23C, so that motor noise, motor gear meshing noise, etc. Can be reduced. This makes it possible to reduce the noise of the device.

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

  For example, if the motor gear 2 is divided into a path for transmitting drive to the Y, M, and C color photosensitive drums and a path for transmitting drive to the Y, M, and C color developing devices, the following problems occur. That is, in order to transmit the drive force to the C-color developing device far away from the motor gear 2, it is necessary to provide many gears. As a result, the cost of the device may increase due to an increase in the number of parts, and the size of the device may increase. In addition, gear meshing noise increases. On the other hand, in this embodiment, the electromagnetic clutch 7 is attached to the rotary 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 made common to the middle, the number of gears can be reduced, and the photoconductor drum and the developing device can be provided with a color motor. The driving force can be transmitted.

  Further, in this embodiment, by providing the electromagnetic clutch on the rotary shaft to which the photoconductor gear is fixed, the developing gear meshing with the developing output gear and the developing drive joint are integrated into the driving side developing gears 8Y, 8M and 8C. Can be used. As a result, the number of parts can be reduced. Further, the drive-side developing gears 8Y, 8M, and 8C can be assembled by simply inserting the drive-side developing gears 8Y, 8M, and 8C so as to be rotatable on the support shaft that is fixed to the rear side plate 10 by caulking, and the assembling property 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 of Modification 1 that is a first modification of Embodiment 1, where FIG. 8A is a schematic cross-sectional view, and FIG. 8B is a rear side plate 10. FIG. 11 is a view of a color driving device 110A according to Modification 1 from which the bracket 9 is 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 mounting the color motor 1 on the surface of the back side plate 10 facing the process unit, the axial length of the color driving device can be shortened as compared with 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 arranged inside the device, the sound generated from the color motor 1 can be shielded by the back side plate 10 or the bracket 9. As a result, the sound generated from the color motor 1 can be suppressed from leaking to the outside of the printer, and the noise of the printer can be reduced.

[Modification 2]
FIG. 9 is a perspective view of a color driving device 110B of Modification 2 which is a second modification of Embodiment 1, and FIG. 10 is a schematic configuration diagram of the color driving device 110B of Modification 2. FIG. 10A is a schematic cross-sectional view of a color driving device 110B of Modification 2, and FIG. 10B shows a color driving device 110B of Modification 2 in which the back side plate 10 and the bracket 9 are removed. It is the figure which looked at the back side. In addition, FIG. 10C is a front view of the color driving device 110</b>B of the second modification in which the back side plate 10 and the bracket 9 are removed.

  In the second modification color driving device 110B, the inter-axis distance (st pitch) between the shafts (rotary shafts 17) of the photoconductor drums 24 of the respective colors is made small in order to downsize 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, when the color motor is arranged inside the apparatus and the motor gear 2 is directly meshed with the photoconductor gear as in the modified example 1, the motor substrate 1a and the mounting member 1b interfere with the rotary 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 point) of the motor idler gear 13. In the second modification, the 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 set to the M color photoconductor gears 3M and Y. It may be provided between the color photoconductor gear 3Y.

  In such a configuration, the color driving device is larger in the up-down direction than the configuration of the first modification, but can be downsized in the axial direction as in the first modification. Further, also in the color driving device 110B of the second modification, since the color motor 1 is arranged on the inner side, it is possible to suppress the sound of the motor from leaking out of the device.

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

[Modification 3]
FIG. 11 is a schematic configuration diagram of a color driving device 110C according to Modification 3 which is a third modification of the first embodiment. FIG. 11A is a schematic cross-sectional view of a color driving device 110C of Modified Example 3, and FIG. 11B shows a color driving device 110C of Modified Example 3 in which the back side plate 10 and the bracket 9 are removed. It is the figure seen from the back side. FIG. 11C is a front view of the color driving device 110C according to Modification 3 in which the rear side plate 10 and the bracket 9 are removed.

  In the color driving device 110C of the third modification, the motor idler gear is the internal gear 13A. Specifically, the internal gear 13</b>A has a tubular shape with its inner side closed, and has internal teeth formed on its inner peripheral surface and external teeth formed on its outer peripheral surface. The motor gear 2 meshes with the internal teeth of the internal gear, and the external teeth of the internal gear are meshed with the Y-color photoconductor gear 3Y and the M-color photoconductor gear 3M.

  When the motor idler gear is an internal gear, the meshing ratio 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 meshing noise can be shielded by the internal gear 13A. Further, since the inner side of the internal gear 13A is closed, it is possible to prevent the meshing noise from leaking to the outside. This makes it possible to reduce the noise of the device as compared with the color driving device 110B of the second modification.

FIG. 12 is an enlarged view of the broken line portion C shown in FIG.
As shown in FIG. 12, the internal teeth of the internal gear 13A and the motor gear 2 that meshes with the internal teeth are helical teeth. The external teeth of the internal gear 13A and the photoconductor 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 such that the end portion of the motor shaft on the front end side is on the downstream side in the normal rotation direction with respect to the end portion of the motor on the rotor side. 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. As a result, the color motor is pressed against the rear side plate 10, and the posture of the color motor can be stabilized during normal driving. As a result, uneven rotation can be suppressed. Further, it is possible to suppress the vibration of the color motor and reduce the noise of the motor. It should be noted that the normal rotation and the normal driving are the rotation during image formation and the driving.

  Further, it is preferable that the external teeth of the internal gear 13</b>A are helical teeth whose twist direction is the same 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 device, as indicated by an arrow X1 in the figure. On the other hand, the external teeth of the internal gear receive thrust force on the inner side of the device. As a result, the thrust forces are canceled out, and the internal gear can be prevented from coming into contact with the back side plate 10 or the bracket 9.

  Further, it is preferable that the development output gears 6Y and 6M are helical teeth having the same twisting direction as the photoconductor gears 3Y and 3M. By setting the external teeth of the internal gear 13A to be helical teeth that are twisted in the same direction as the internal teeth, the photoconductor gears 3Y and 3M generate thrust force acting on the inner side of the device as indicated by an arrow X2 in the figure. receive. By making the development output gears 6Y and 6M be helical teeth having the same twisting direction as that of the photoconductor gears 3Y and 3M, the development output gears 6Y and 6M receive thrust force on the inner side of the apparatus. As a result, when the driving force is being transmitted to the rotating body of the developing device, the thrust force is canceled out, and the photoconductor 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 the thrust force acting on the inside of the device, as indicated by the arrow X2 in the figure. As a result, the photoconductor gears 3Y and 3M can be brought into contact with the inner side plate 10 on the inner side. As a result, it is possible to suppress the noise due to the meshing vibration from leaking to the outside, as compared with the case where the bracket 9 on the outside of the apparatus is brought into contact with the bracket 9.

[Modification 4]
FIG. 13 is a schematic configuration diagram of a color driving device 110D of Modification 4 which is the fourth modification of the first embodiment. 13A is a schematic cross-sectional view of a color driving device 110D of Modification 4, and FIG. 13B shows a color driving device 110D of Modification 4 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 front view of the color driving device 110D according to Modification 3 in which the back side plate 10 and the bracket 9 are removed.

  Generally, the electromagnetic clutches 7Y, 7M, and 7C have shorter lives than gears and the like, and require periodic replacement. When the electromagnetic clutch is arranged inside the photoconductor gear and the development output gear, when exchanging the electromagnetic clutch, the photoconductor gear and the development output gear need to be removed, which makes the exchange of the electromagnetic clutch complicated. is there.

  Therefore, in the color driving device 110D of the fourth modification, in order to enhance the exchangeability of the electromagnetic clutch, the electromagnetic clutches 7Y, 7M, 7C are provided coaxially with the photoconductor gears 3Y, 3M, 3C and the developing output gears. It was provided outside of 6Y, 6M, and 6C. Further, the bracket 9 is provided with a hole 9a for accessing the electromagnetic clutches 7Y, 7M, 7C, and the hole 9a is closed by the cap member 15.

  In the color driving device 110D of Modification 4, when replacing the electromagnetic clutch, the exterior cover on the back side of the printer is removed to expose the bracket 9. Next, the cap member 15 is removed to expose the electromagnetic clutch through the hole 9a of the bracket 9. Then, the electromagnetic clutch is moved in the axial direction, the electromagnetic clutch is removed from the rotary shaft through the hole 9a, and a new electromagnetic clutch is attached to the rotary shaft.

  As described above, in the color driving device 110D of Modification 4, the bracket 9 is provided with the hole 9a for accessing the electromagnetic clutch, so that the electromagnetic clutch can be replaced without removing the bracket 9. .. Further, the electromagnetic clutch can be replaced without removing the photoconductor gears 3Y, 3M, 3C and the development output gears 6Y, 6M, 6C from the rotary shaft. This makes it possible to easily replace the electromagnetic clutch.

  Further, in this modified example 4, the color motor is attached to the motor attachment surface portion 9c attached to the support shaft 9b extending vertically from the surface of the bracket 9 facing the rear side plate 10. With this structure, the color motor 1 can be arranged above the developing output gear 6 and the electromagnetic clutch 7. As a result, the axial length of the color driving device can be shortened as compared with the case where the color motor 1 is mounted on the surface of the bracket 9 opposite to the surface facing the rear side plate 10. 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 drive devices of the embodiment and the modified examples 1 to 4, the electromagnetic clutch is provided on the rotating shaft that transmits the driving force to the photosensitive drum. An impact is generated in the electromagnetic clutch when switching from ON to OFF or when switching from OFF to ON, and the impact becomes vibration and propagates to the photoconductor drum via the rotary shaft and the photoconductor joint. Then, the photosensitive drum may vibrate and an abnormal image such as shock jitter may occur. Therefore, it is necessary to turn on/off the electromagnetic clutch 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 surface of the photoconductor 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 from the time when the driving of the motor is started and the photosensitive drum starts to rotate until the surface of the photosensitive drum is uniformly charged by the charging device 25. Switch. If the impact of switching the electromagnetic clutch from OFF to ON does not affect the uniform charging of the surface of the photoconductor, the electromagnetic clutch is switched from OFF to OFF between the exposure start timing t3 and the charging start timing t2. You may switch to ON. During the exposure process, when the photosensitive drum vibrates due to the impact of switching the electromagnetic clutch from OFF to ON, it affects the electrostatic latent image. Therefore, switch the electromagnetic clutch from OFF to ON at least before starting the exposure. It is preferable to carry out.

  Further, in FIG. 14, the electromagnetic clutch is switched from ON to OFF after the fixing process is completed, but the timing at which the electromagnetic clutch is switched from ON to OFF after the developing process can be advanced within a range that does not affect the image. However, when the electromagnetic clutch is switched from ON to OFF during the primary transfer process, the vibration of the photosensitive drum affects the image transferred to the intermediate transfer belt. 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 another photosensitive drum via the back side plate 10 and the bracket 9 and affect the rotational speed of the other photosensitive drum. 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. In addition, when the impact when the electromagnetic clutch is switched from ON to OFF is propagated to the intermediate transfer belt via the photoconductor 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 OFF to OFF.

  Further, in the above description, the example in which the electromagnetic clutch is provided on the rotary shaft to which the photoconductor gear is fixed has been described. However, the driving force is output to the developing device 23 that is a unit including the developing roller 81 that is the second rotating body. An electromagnetic clutch may be provided coaxially with the drive side developing joint which is the second drive output member. Hereinafter, an example in which an electromagnetic clutch is provided coaxially with the drive side developing joint will be described as a second embodiment. Note that, in the following description, the description of the same configuration as the color driving device described in the embodiment will be appropriately omitted.

[Example 2]
FIG. 15 is a schematic configuration diagram showing the color driving device 210 of the second embodiment.
As shown in FIG. 15, the color driving device 210 of the second embodiment includes a Y-color photoconductor drive transmission member 130Y, an M-color photoconductor drive transmission member 130M, and a C-color photoconductor drive transmission member 130C. There is. The photoconductor drive transmission members 130Y, 130M, and 130C for the respective colors have a photoconductor gear portion 130a, a development output gear portion 130b, and a shaft portion 130c. External teeth are formed at the tip of the shaft portion 130c, which serves as a spline shaft.

  The photoconductor gear portion 130a of each color is arranged between the bracket 9 and the back side plate 10 facing the surface of the bracket 9 on the process unit side. 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 mesh with the motor gear 2 of the color motor 1. 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 mesh with the developing output gear portions 130b of the photoconductor drive transmitting members 130Y, 130M and 130C of the respective colors. The developing gears 51Y, 51M and 51C of 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, developing output shafts 53Y, 53M, 53C extending from the driving side developing joints 52Y, 52M, 52C are rotatably supported on the inner peripheral surfaces of the bearing members 54Y, 54M, 54C.

  The electromagnetic clutches 7Y, 7M, 7C are attached to the developing output shafts 53Y, 53M, 53C and engage with the developing gears 51Y, 51M, 51C from the axial direction. Further, the drive-side developing joints 52Y, 52M, 52C as the second driving output member integrated with the developing output shafts 53Y, 53M, 53C have a cylindrical shape, and inner teeth are formed on the inner peripheral surface thereof.

FIG. 16 is a schematic cross-sectional view showing the color driving device and the C, M, and Y color process units of the second embodiment.
Since the drive transmission mechanism on the side of each process unit has the same configuration, the process unit of C color 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 rear end of the photoconductor drum 24. The driven-side photoconductor joint 124 has a cylindrical shape and has inner teeth formed on its inner peripheral surface. The driven-side 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 outer teeth of the spline shaft and the inner teeth of the driven-side photoconductor joint 124 mesh with each other to form the photoconductor drum 24. It is drivingly connected to the color driving device of Example 2.

  A driven-side developing gear 180 including a driven gear portion 180b and a driven-side developing joint portion 180a formed integrally with each other is provided at the rear end of the toner supply roller 80 of the developing device 23. A developing roller gear 181 is provided at the rear end of the developing roller 81, and the developing roller gear 181 meshes with a driven gear portion 180b via a developing idler gear 182. The driven-side developing joint portion 180a serves as a spline shaft. By inserting the driven-side developing joint portion 180a of the driving-side developing joint 52, the outer teeth of the driven-side developing joint portion 180a and the inner teeth of the driving-side developing joint 52 mesh and are drivingly connected.

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

  When the color motor 1 is rotationally driven, the driving force is transmitted via the motor gear 2 to the photoconductor gear portion 130a of the photoconductor drive transmission member 130M, and the photoconductor drive transmission member 130M is rotationally driven. When the photoconductor drive transmission member 130 is rotationally driven, the driving force is transmitted to the driven side photoconductor joint connected to the shaft portion 130c of the photoconductor drive transmission member 130M, and the photoconductor 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 photoconductor drive transmitting member 130M.

  As shown in FIG. 17A, when the electromagnetic clutch 7M is OFF, the developing gear 51M idles with respect to the developing output shaft 53, and the driving force is not transmitted from the developing gear 51M to the developing 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 via 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 the C color, the driving force is transmitted from the motor gear 2 to the photoconductor gear portion 130a of the photoconductor drive transmission member 130M. After that, the driving force is transmitted in the same manner as described above, and the photoconductor drum 24C and the rotating body of the developing device 23C are rotationally driven. To the Y-color photoconductor drum 24Y and each rotating body of the developing device 23Y, the Y-color photoconductor drive transmission member 130Y is transferred to the color motor 1 via the motor gear 2, the M-color photoconductor drive transmission member 130M, and the idler gear 11. Driving force is transmitted. After that, the drive transmission is similarly 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 1 drives the color photoconductor 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 the case where the drive motor for driving the color photoconductor drums 24Y, 24M, 24C and the drive motor for driving the rotating bodies of the color developing devices 23Y, 23M, 23C are separately provided. it can. As a result, the cost of the device can be reduced. Further, the size of the device can be reduced. Further, since one motor drives the color photoconductor drums 24Y, 24M and 24C and the rotating body of the color developing devices 23Y, 23M and 23C, it is possible to reduce motor noise and motor gear meshing noise. it can. This makes it possible to reduce the noise of the device.

  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 rotationally driven, the electromagnetic clutches 7Y, 7M and 7C can be turned off to stop the driving of the color developing devices 23Y, 23M and 23C. As a result, it is possible to prevent the developing device from reaching its end of life at an early stage.

  In the second embodiment, the electromagnetic clutch 7 is attached to the developing output shaft 53 that is coaxial with the driving side developing joint 52M that is the second driving output member that outputs the driving force to the developing device. Even if 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 to some extent, as in the first embodiment. This makes it possible to reduce the number of gears and transmit the driving force of the color motor to the photosensitive drum and the developing device.

  Further, in the second embodiment, by providing the developing output shaft 53 with the electromagnetic clutch, the photosensitive member drive transmission member 130Y in which the photosensitive member gear, the developing output gear, and the shaft for outputting the driving force to the photosensitive drum are integrated. , 130M, 130C can be used. This can reduce the number of parts. Further, the photosensitive member drive transmission members 130Y, 130M and 130C can be assembled to the bracket 9 only by being rotatably supported, and the assembling property can be improved.

  Generally, the rotating body (developing roller or supply roller) of the developing device is required to rotate at a higher speed than the photosensitive drum. Therefore, the speed is increased in the drive transmission from the developing output gear unit 130b to the developing gear 51, and the developing gear has a higher rotation speed and the torque is smaller than that of the photoconductor drive transmitting member. As described with reference to FIG. 5 above, the electromagnetic clutch magnetically adsorbs the relatively rotating armature 7b to the rotor portion 7c to perform drive transmission between the armature 7b and the rotor portion 7c. It is a thing. Therefore, when the electromagnetic force is weak with respect to the torque at the time of this attraction, the armature 7b slides relative to the rotor portion 7c, and the drive cannot be transmitted correctly. Therefore, as the electromagnetic clutch used, it is necessary to increase the electromagnetic force according to the load torque applied to the electromagnetic clutch. The one that can generate a stronger electromagnetic force becomes larger in size as an electromagnetic clutch and the cost becomes higher. Therefore, as in the first embodiment, the electromagnetic clutch is provided on the developing output shaft that is the shaft that outputs the driving force to the developing device, rather than the electromagnetic clutch that is provided on the shaft that outputs the driving force to the photosensitive drum 24. The load torque applied to the electromagnetic clutch can be reduced. As a result, it is possible to use an electromagnetic clutch that is smaller and less expensive than an electromagnetic clutch provided on the shaft that outputs the driving force to the photosensitive drum 24. As a result, the size of the device can be reduced, and the cost increase of the device can be suppressed.

  The development output shaft 53 and the drive side development joint 52 are a resin integrally molded product, 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 rotatably supported on the developing output shaft 53, the resins contact each other. The surface treatment of resin is more difficult than that of metal, and the smoothness of the resin surface is inferior to that of metal. Therefore, when the developing gear 51 is directly rotatably supported on the developing output shaft 53, the sliding resistance becomes higher than when it is rotatably supported on the surface of the metal. 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. As a result, sliding resistance is reduced and abrasion of the developing gear can be suppressed as compared with the case where the developing gear 51 is rotatably supported by the resin developing output shaft 53. In addition, the number of parts can be reduced and the cost of the apparatus can be reduced as compared with 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. You can

  Further, in the second embodiment, the drive transmission from the photoconductor drive transmission member to the drive side developing joint 52 is performed by the meshing of the gears of the developing output gear portion 130b and the developing gear 51. As a result, durability can be improved as compared with the case where drive transmission is performed by a belt.

  Next, a modified example 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 that is a first modification of the second embodiment.
In the color driving device 210A of the modified example A, the drive transmission from the photoconductor drive transmission members 130Y, 130C, 130M to the drive side developing joints 52Y, 52M, 52C is belt transmission. Specifically, the development output gear portion 130b of the photoconductor drive transmission members 130Y, 130M, 130C of the second embodiment is changed to the development output pulley portion 130d, and the development gears 51Y, 51C, 51M are replaced with the development pulleys 56Y, 56M. , 56C. Timing belts 55Y, 55M and 55C are stretched around the developing output pulley portion 130d of the photoconductor drive transmission members 130Y, 130M and 130C and the developing 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, 55C stretched between the development output pulley section 130d of the photoconductor drive transmission members 130Y, 130M, 130C and the development pulleys 56Y, 56M, 56C are elastically deformed, It is possible to absorb the vibration generated when the electromagnetic clutch is switched ON/OFF. As a result, compared to the second embodiment, it is possible to suppress the vibration of the photoconductor drive transmission members 130Y, 130M, and 130C due to the influence of the vibration when the electromagnetic clutch is switched on/off. As a result, it is possible to prevent the vibrations of the photoconductor drums from propagating from the photoconductor drive transmission members 130Y, 130M, and 130C to vibrate the photoconductor drums, and to suppress the occurrence of abnormal images such as shock jitter. ..

  The timing belts 55Y, 55M and 55C can also elastically deform and absorb the uneven rotation of the rotating body of the developing device, and the uneven rotation of the rotating body of the developing device can reduce the influence of the uneven rotation of the developing device. , 130C can be suppressed.

[Modification B]
FIG. 19 is a schematic configuration diagram of a color driving device 210B of Modification B that is the second modification of the second embodiment.
In the color driving device 210B of the modified example B, the development output gear portions of the photoconductor drive transmission members 130Y, 130M and 130C have internal teeth 130e. Further, in this modification B, the drive side development joints 52Y, 52M and 52C are separately provided from the development output shafts 53Y, 53M and 53C and are rotatably supported by the development output shafts 53Y, 53M and 53C. Further, the developing gears 51Y, 51M and 51C are attached to the developing output shafts 53Y, 53M and 53C so as to rotate integrally with the developing output shafts 53Y, 53M and 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, the internal teeth 130e of the photoconductor drive transmission members 130Y, 130M and 130C are drive-transmitted 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, the drive transmission from the developing output shaft to the driving side developing joint is cut off, and the rotating body (developing roller or supply roller) of the developing device is in a stopped state. When the electromagnetic clutch is ON, the driving force is transmitted from the developing output shaft to the driving side developing 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 has internal teeth, whereby the meshing ratio 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 inner side of the inner teeth 130e is closed, it is possible to prevent 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 using the internal teeth for the development output gear portion, as shown in FIG. 19, the photoconductor gear portion 130a, the development output gear portion, and the development gear 51 are arranged at the same position in the axial direction. You can As a result, the size can be reduced 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 developing output gear portion can be made larger than that in the case where the developing output gear portion has external teeth. As a result, it is possible to increase the number of teeth of the development output gear portion, and it is possible to obtain a high speed increasing ratio by meshing the development gear portion and the development gear.

[Modification C]
FIG. 20 is a schematic configuration diagram of a color driving device 210C of Modification C that is a third modification of the second embodiment.
The third modification is provided with a cover member 140 that covers the drive transmission member on the photoconductor drum side with respect to the back side plate 10 of the color driving device. 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 a screw 141.

  Further, the development output shafts 53Y, 53M, 53C integrated with the drive side development joints 52Y, 52M, 52C are only rotatably supported on the inner circumferences 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 cause the bearing members to move. There was a risk that it would come off from 54Y, 54M, and 54C. In this modification C, the cover member 140 covers the electromagnetic clutch and the drive-side developing joints 52Y, 52M, and 52C, so that it is possible to prevent objects or the like from touching them. As a result, it is possible to prevent the development output shafts 53Y, 53M, 53C from coming off the bearing members 54Y, 54M, 54.

  Furthermore, in this modification C, the retaining projections 152Y, 152M, 152C for preventing the developing output shafts 53Y, 53M, 53C from coming off the bearing members 54Y, 54M, 54C by hitting the cover member 140 are provided with the drive side. It is provided on the outer peripheral surfaces of the developing joints 52Y, 52M and 52C. This can prevent the development output shafts 53Y, 53M, 53C from coming off from the bearing members 54Y, 54M, 54C.

[Modification D]
FIG. 21 is a schematic perspective view of a color driving device 210D of Modification D that is a fourth modification of the second embodiment.
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 photoconductor gear portion, similarly to the color driving device 110B of the modified example 2 shown in FIG. It is a thing.

  In the modification D as well, as in the modification 2, even if the inter-axial distance of the photosensitive drums 24 of each color is smaller than the width of the motor substrate of the color motor 1 or the mounting member, the color motor 1 is , Can be arranged between the photoconductor gear portion and the photoconductor drum. Therefore, the size of the device can be reduced. Further, the meshing with the first-stage motor gear can be made to be one, and the noise can be suppressed as compared with the configuration in which the two photoconductor gear portions are meshed with the first-stage motor gear.

  Further, in this modification D, the motor idler gear 13 is an internal gear. Therefore, similarly to the modification 3 shown in FIG. 11, the meshing ratio 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, and the meshing noise can be shielded by the internal gear. Further, since the inner side of the internal gear is closed, it is possible to prevent the meshing noise from leaking to the outside. This makes it possible to reduce the noise of the device.

[Modification E]
FIG. 22 is a schematic configuration diagram of a color driving device 210E of Modification E that is a fifth modification of the second embodiment.
In the color driving device 210E of the modification E, the developing gears 51Y, 51M, 51C are provided with cylindrical boss portions 151Y, 151M, 151C. The bosses 151Y, 151M, 151C are inserted into the holes 10a of the rear side plate 10 to rotatably support the developing gears 51Y, 51M, 51C on the rear side plate 10. The development output shafts 53Y, 53M, 53C are rotatably received by the boss portions 151Y, 151M, 151C and rotatably supported by the rear side plate 10.

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

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

  In addition, as a basic configuration of the black driving device that rotationally drives the K-color photosensitive drum 24K and the rotating body (developing roller 81 and toner supply roller 80) of the developing device 23K, the above-described Embodiment 2 and Modifications A to E are used. The configuration of can also be adopted. That is, a photoconductor drive having a drive motor, a motor gear of the drive motor, a photoconductor gear unit, a development output gear unit that transmits the drive force to the rotating body of the developing device, and a shaft unit 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 the driving force to the developing device.

What has been described above is an example, and each of the following aspects has a unique effect.
(Aspect 1)
A drive motor, a first drive transmission path that transmits the drive force of the drive motor to a first rotating body, and a drive that can switch between a state in which the drive force of the drive motor is transmitted and a state in which the transmission of the drive force is cut off. In a drive device having a transmission switching means and a second drive transmission path for transmitting the driving force to a second rotating body, the drive transmission switching means is provided in the first drive transmission path. It is provided on a rotary shaft that rotates integrally with the member.

  In the drive device described in Patent Document 1, a drive transmission member such as a photoconductor 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. At the motor gear, the drive transmission path is divided into a first drive transmission path and a second drive transmission path. In such a configuration, in the case where the second rotating body such as the developing roller is provided on the opposite side of the motor gear with the rotating shaft such as the shaft portion that rotates integrally with the drive transmission member such as the photoconductor gear interposed therebetween. The drive transmission switching means is arranged as follows. That is, since the input gear of the drive transmission switching means meshes with the motor gear, the drive transmission switching means is arranged on the opposite side of the second rotary body with the rotary shaft interposed therebetween. As a result, the rotation shaft interferes, and the output gear of the drive transmission switching means and the gear at the most downstream stage of the second drive transmission path such as the developing gear cannot be directly meshed with each other. Therefore, an idler gear is provided, and drive transmission is performed between the output gear and the most downstream gear of the second drive transmission path via the idler gear.

  On the other hand, in the aspect 1, the drive transmission switching means such as the electromagnetic clutch is provided on the rotary shaft that rotates integrally with the drive transmission member such as the photoconductor gear provided in the first drive transmission path. As a result, the first drive transmission path and the second drive transmission path are common drive transmission paths from the motor gear to the rotation shaft, and the first drive transmission path and the second drive transmission path branch at the rotation shaft. It will be composed. With such a configuration, even if the second rotating body is provided on the opposite side of the motor gear of the drive motor with the rotating shaft interposed therebetween, the drive transmission switching means does not use the idler gear to drive the second drive member. It becomes possible to directly transmit the driving force to the gear on the most downstream side of the transmission path (the developing gear portion 8a in this embodiment). Thereby, unlike the drive device described in Patent Document 1, an idler gear is not 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 drive motor such as the color motor 1, a first drive transmission path for transmitting the drive force of the drive motor to a first rotating body such as the photosensitive drum 24, a state and drive for transmitting the drive force of the drive motor 1. A drive device having a drive transmission switching means such as an electromagnetic clutch capable of switching between a state in which the transmission of force is cut off, and a second drive transmission path for transmitting the drive force to a second rotating body such as a developing roller. In the above, the drive transmission switching means is provided coaxially with a second drive output member such as a drive side developing joint 52 that outputs the driving force to a unit such as the developing device 23 including the second rotating body.

  In this aspect 2 as well, as in aspect 1, from the motor gear to the rotary shaft such as the shaft portion 130c, the first drive transmission path and the second drive transmission path are common drive transmission paths, and the first drive transmission path and the second drive transmission path are located at the rotary shaft. The drive transmission path and the second drive transmission path may be branched. With this configuration, even if the second rotating body is provided on the opposite side of the motor gear of the drive motor with the rotation shaft interposed therebetween, the second drive transmission path is most downstream without the idler gear. The driving force can be transmitted to the gear (developing gear in the second embodiment). Thereby, unlike the drive device described in Patent Document 1, the idler gear is not 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 driving device as compared with the driving device described in Patent Document 1.

(Aspect 3)
In (Aspect 2), the driving force is provided via a drive transmission member such as the photoconductor drive transmission member 130 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. A second drive transmission member such as a developing gear 51 to be transmitted is rotatably supported on the outer peripheral surface, and a rotation shaft such as a development output shaft 53 to which the second drive output member is attached is rotatably supported on the inner peripheral surface. A bearing member 54 for receiving 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 device 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 developing 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 photoconductor drive transmission member 130 that constitutes the.
According to this, the drive transmission member such as the photoconductor drive transmission member 130 forming the first drive transmission path is branched to the second drive transmission path. As a result, 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 of the drive motor with the motor gear interposed therebetween. Even with the above configuration, the idler gear is unnecessary, 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 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 the drive transmission is performed by the 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 modification B, it is possible to suppress vibration and noise as compared with the case where the second drive transmission path is configured by only the external gear. Further, the meshing portion with the internal gear can be covered with the internal gear, and meshing noise can be shielded by the internal gear. This makes it possible to reduce the noise of the device as compared with the case where the second drive transmission path is configured only by the external gear.

(Aspect 7)
In (Aspect 4), the second drive transmission path has a belt drive transmission portion.
According to this, as described in the modified 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 elastically deforming the belt member of the belt drive transmission portion. As a result, it is possible to suppress the influence of vibration of the drive transmission switching means during the drive transmission switching 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 stops at a predetermined timing during the rotation of the first rotating body such as the photosensitive drum 24.
According to this, by switching from the state of transmitting the driving force to the state of interrupting the transmission of the driving force by the driving transmission switching means such as the electromagnetic clutch 7, the two rotating bodies such as the developing roller 81 and the like such as the photosensitive drum 24 are separated. The rotation can be stopped during the rotation of the first rotating body. Thereby, the life of the second rotating 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 a developing roller 81.
As described in the embodiment, the developing roller 81 has a shorter life than the photoconductor such as the photoconductor drum 24, but the development roller 81 can stop the rotation of the development roller 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 the drive motor such as the color motor 1 are arranged such that the tip end side of the motor shaft is in a normal rotational operation The helical tooth was twisted so as to be located on the downstream side in the rotation direction of.
The “normal rotation operation” is the rotation direction in which the rotation time is longer during the predetermined period, and in the present embodiment, the image forming operation corresponds to the normal rotation operation.
According to this, as described in the modification 3, the motor gear 2 receives the thrust force directed toward the tip 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 on which the drive motor such as the bracket 9 or the rear side plate 10 is mounted. As a result, it is possible to stabilize the posture of the drive motor during driving and suppress uneven rotation. 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 a motor gear 2 of a drive motor such as a color motor 1 is provided, and a drive transmission member such as a photoconductor gear 3 has an outer periphery of the internal gear 13A. It is a gear that meshes with external teeth provided on the surface.
According to this, as described in Modification 3 and Modification D, the engagement 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 meshing noise can be shielded by the internal gear 13A. Further, compared with the external gear, the size in the radial direction can be suppressed to increase the reduction ratio, 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 Modification 3, the direction of the thrust force received by the internal tooth portion of the internal gear and the direction of the thrust force received by the external tooth portion of the internal gear can be made opposite to each other. As a result, the thrust force of the internal gear of the internal gear can be canceled by the thrust of the external gear, and the internal gear can be prevented from moving in either axial direction. This can prevent the internal gear from coming into contact with the back side plate 10 or the bracket 9.

(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 rotating body such as the photoconductor drum 24. It was placed between the rotating body.
According to this, as described in Modification 1 and Modification D, the drive device can be downsized 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 to which the driving force is transmitted from the drive transmission switching unit such as the electromagnetic clutch 7 are arranged coaxially. The drive output member such as the developing output gear 6 is a helical gear having the same twisting direction.
According to this, as described in Modification 3, the direction of the thrust force received by the drive transmission member such as the photoconductor gear 3 and the direction of the thrust force received by the drive output member such as the development output gear 6 are opposite to each other. The thrust forces can be canceled out. Accordingly, when the drive transmission switching means such as the electromagnetic clutch 7 is in the state of transmitting the drive force of the drive motor, it is possible to prevent the rotation shaft from moving in either axial direction. As a result, when the drive transmission switching means such as the electromagnetic clutch 7 transmits the drive force of the drive motor, the photoconductor gear or the like fixed to the rotary shaft moves together with the rotary shaft, and the back side plate 10 is moved. 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 to which the driving force is transmitted from the drive transmission switching unit such as the electromagnetic clutch 7 are arranged coaxially. The drive output member such as the developing output gear 6 is arranged closer to the first rotating body such as the photosensitive drum 24 than the drive transmission switching means.
According to this, as described in the modified example 4, the drive transmission member such as the photoconductor gear 3 and the drive output member such as the development output gear 6 are not removed from the rotary shaft 17, and the drive transmission such as the electromagnetic clutch 7 is performed. The switching means can be removed from the rotary 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, when the electromagnetic clutch is turned on, the driving force can be transmitted, and when the electromagnetic clutch is turned off, the driving force can be interrupted.

(Aspect 17)
A developing device 23 having a photoconductor such as the photoconductor drum 24 and a developing roller 81, for developing a latent image formed on the surface of the photoconductor, and a driving device for driving the photoconductor and the developing roller. In the image forming apparatus including, the driving device according to any one of (Aspect 1) to (Aspect 16) is provided as the driving device.
According to this, the cost of the image forming apparatus can be reduced, and the size of the image forming apparatus can be reduced.

(Aspect 18)
In (Aspect 17), a charging device 25 that uniformly charges the surface of a photoconductor such as the photoconductor drum 24, and a latent image forming device such as an optical writing unit 27 that forms an electrostatic latent image on the surface of the photoconductor. And a transfer device such as a primary transfer roller 74 that transfers the image formed on the surface of the photoconductor to a transfer body such as the intermediate transfer belt 22, and the first rotating body is the photoconductor, 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 interrupted to a state in which the driving force is transmitted before the latent image formation by the latent image forming device is started. After the image transfer by the transfer device is completed, the state of transmitting the driving force is switched 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 generation of an abnormal image such as a shock jitter due to the impact of switching the transmission state by the drive transmission switching unit 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: Drive side development gear 8a: Development gear portion 8b: Drive side development joint portion 9: Bracket 9a: Hole portion 10: Back side plate 11: Idler gear 13: Motor idler gear 13A: Internal gear 15: Cap member 17: Rotation Axis 22: Intermediate transfer belt (transfer body)
23: developing device 24: photoconductor drum (photoconductor)
25: Charging device 26: Process unit 27: Optical writing unit 51: Development gear 52: Drive 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 drive device 110A: Color drive device 110B of Modification 1; Color drive device 110C of Modification 2; Color drive device 110D of Modification 3; Modification 4 Color driving device 112: drive side photoconductor joint 124: driven side photoconductor joint 130: photoconductor drive 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 protrusion 180: Driven side developing gear 180a: Driven side developing joint portion 180b: Driven gear portion 181: Developing roller gear

JP2012-208458A

Claims (13)

Drive motor,
A first drive transmission path for transmitting the drive force of the drive motor to the first rotating body;
A second drive transmission path for transmitting the drive force to the second rotating body, which has drive transmission switching means capable of switching between a state in which the drive force of the drive motor is transmitted and a state in which the transmission of the drive force is interrupted. In the provided drive device,
The drive transmission switching means, set to a rotating shaft that rotates the drive transmission member and integrally constituting the first drive transmission path,
The second drive transmission path has a gear train,
The drive transmission member and the drive output member arranged coaxially with the drive transmission switching unit to which the driving force is transmitted from the drive transmission switching unit are helical gears having the same twist direction. Drive device.   The drive device according to claim 1,
The drive transmission member and the drive output member coaxially arranged with the drive transmission switching unit to which the driving force is transmitted from the drive transmission switching unit are arranged closer to the first rotating body than the drive transmission switching unit. A drive device characterized by.   Drive motor,
A first drive transmission path for transmitting the drive force of the drive motor to the first rotating body;
A second drive transmission path for transmitting the drive force to the second rotating body, which has drive transmission switching means capable of switching between a state in which the drive force of the drive motor is transmitted and a state in which the transmission of the drive force is interrupted. In the provided drive device,
The drive transmission switching means is provided on a rotary shaft that rotates integrally with a drive transmission member that constitutes the first drive transmission path,
The second drive transmission path has a gear train,
The drive transmission member and the drive output member coaxially arranged with the drive transmission switching unit to which the driving force is transmitted from the drive transmission switching unit are arranged closer to the first rotating body than the drive transmission switching unit. A drive device characterized by. The drive device according to any 請 Motomeko 1 to 3,
The second drive transmission path includes an internal gear, and a drive device. The drive device according to any one of claims 1 to 4 ,
The drive device, wherein the second rotating body is stopped at a predetermined timing while the first rotating body is rotating. The drive device according to any one of claims 1 to 5 ,
The driving device, 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 6 ,
The teeth of the motor gear provided on the motor shaft of the drive motor are helical teeth that are twisted so that the tip end side of the motor shaft is located on the downstream side in the rotation direction during normal rotation operation of the motor shaft. A drive device characterized by. The drive device according to one of claims 1 to 7 have shifted,
An internal gear that meshes with the motor gear of the drive motor,
The drive device, wherein the drive transmission member forming the first drive transmission path 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 claim 8 ,
A drive device in which the internal tooth portion of the internal gear and the external tooth portion are helical teeth having the same twist direction. The drive device according to one of claims 1 to 9 have shifted,
The drive device is characterized in that the drive motor is arranged between a drive transmission member forming the first drive transmission path and the first rotary body in an axial direction of the first rotary body . The drive device according to any 請 Motomeko 1 to 10,
The drive device, wherein the drive transmission switching means is an electromagnetic clutch. A photoconductor,
A developing device having a developing roller for developing the latent image formed on the surface of the photoconductor;
In an image forming apparatus including a driving device that drives the photoconductor and the developing roller,
An image forming apparatus comprising the driving device according to any one of claims 1 to 11 as the drive device. The image forming apparatus according to claim 12 ,
A charging device for uniformly charging the surface of the photoconductor,
A latent image forming device for forming an electrostatic latent image on the surface of the photoreceptor,
A transfer device for transferring the image formed on the surface of the photoreceptor to a transfer body,
The first rotating body is the photoconductor, the second rotating body is the developing roller,
The drive transmission switching unit switches from a state in which the transmission of the driving force is blocked to a state in which the driving force is transmitted before the latent image formation by the latent image forming device is started, and the driving force is changed after the image transfer by the transfer device is completed. An image forming apparatus characterized by switching from a transmission state to a state in which transmission of a driving force is cut off.

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