JP5404845B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus using a process cartridge.

  Here, the electrophotographic image forming apparatus forms an image on a recording medium using an electrophotographic image forming system. Examples of the electrophotographic image forming apparatus include an electrophotographic copying machine, an electrophotographic printer (for example, a laser beam printer, an LED printer, etc.), a facsimile apparatus, a word processor, and the like.

  The process cartridge refers to a cartridge in which at least the developing means and the electrophotographic photosensitive drum are integrated into a cartridge that can be attached to and detached from the main body of the electrophotographic image forming apparatus. The developing device develops the electrostatic latent image formed on the electrophotographic photosensitive drum with a developer.

  2. Description of the Related Art Conventionally, in an electrophotographic image forming apparatus using an electrophotographic image forming process, an electrophotographic photosensitive drum and process means acting on the electrophotographic photosensitive drum are integrally formed into a cartridge. A process cartridge system is employed in which the cartridge can be attached to and detached from the main body of the electrophotographic image forming apparatus. According to this process cartridge system, the maintenance of the apparatus can be performed by the user himself / herself without depending on the service person, so that the operability can be remarkably improved. Therefore, this process cartridge system is widely used in electrophotographic image forming apparatuses.

  In an electrophotographic image forming apparatus, light corresponding to image information such as a laser, an LED, or a lamp is irradiated to an electrophotographic photosensitive drum (hereinafter referred to as a photosensitive drum). As a result, an electrostatic latent image is formed on the photosensitive drum. The electrostatic latent image is developed by a developing device. Further, the developed image formed on the photosensitive drum is transferred to a recording medium. Thereby, an image is formed on the recording medium.

  Patent Document 1 describes an inline-type color electrophotographic image forming apparatus in which a plurality of process cartridges are arranged in a line. Here, in the process cartridge 40, a drum unit 41 having a photosensitive drum 44 and a developing unit 42 having a developing roller 68 are rotatably coupled by a swing center 43. The photosensitive drum 44 is provided with a cartridge coupling 60 at the end of the photosensitive drum 44 in the axial direction. When the process cartridge 40 is mounted on the apparatus main body, the cartridge coupling 60 engages with the main body coupling 61 provided on the apparatus main body, and the driving force is transmitted. Further, a driving force is transmitted to the developing roller 68 via an idler gears 65 and 66 from an input gear 64 as a developing driving force transmitting member provided at the swing center 43 of the developing unit 42. Here, when the process cartridge 40 is mounted on the apparatus main body, the input gear 64 is engaged with a gear 67 provided on the apparatus main body and receives a driving force. That is, drive transmission from the apparatus main body to the photosensitive drum 44 and the developing roller 68 is performed independently.

Japanese Patent Laid-Open No. 2001-255806 (pages 9-11, FIGS. 7-14)

  However, further improvements in image quality have been demanded in recent years. In the conventional example, the input gear is provided at the center of swinging in which the position does not change even when the developing unit swings. Therefore, driving is transmitted from the input gear to the developing roller via the idler gear, and it is necessary to provide a space for this in the process cartridge. Further, the rotation accuracy of the developing roller is affected by the meshing of the input gear, idler gear, and main body gear.

  The present invention is a further development of the above-described prior art.

To achieve the above object, a typical configuration according to the present invention includes a photosensitive drum, a developing roller for developing an electrostatic latent image formed on the photosensitive drum, and one end side in the axial direction of the developing roller. A driven portion fixed to the driven portion, an intermediate portion movable in a direction intersecting the axial direction of the developing roller with respect to the driven portion while maintaining engagement with the driven portion, and the intermediate portion A drive unit that can move in a direction crossing the axial direction of the developing roller with respect to the intermediate part while maintaining engagement, and a coupling unit that receives a driving force for rotating the developing roller, a, a process cartridge is detachably mountable to the image forming apparatus main body, engages with the driving unit, has a body drive unit applying a driving force to said driving portion, an image on a recording material forming in the image forming apparatus, the photoreceptor de A first position for forming an image on a beam, a position retracted from the first position, the image forming apparatus to the a second position for mounting and dismounting the process cartridge, for placing the process cartridge have a moving mechanism, the moving mechanism in a state where said drive portion and said body drive unit is engaged, characterized by moving the photoreceptor drum to said second position and said first position.

  According to the present invention, even when the process cartridge is moved to the first position and the second position, the rotation accuracy of the developing roller can be increased.

1 is an overall configuration diagram of a color electrophotographic image forming apparatus according to an embodiment. FIG. 6 is a cross-sectional explanatory view of a process cartridge. FIG. 6 is a diagram illustrating an operation of mounting a process cartridge to the apparatus main body. FIG. 6 is a diagram illustrating an operation of mounting a process cartridge to the apparatus main body. FIG. 6 is a diagram illustrating an operation of mounting a process cartridge to the apparatus main body. It is a figure explaining the support structure of a developing roller. It is a figure explaining the structure of Oldham coupling. It is a section explanatory view of Oldham coupling. It is a section explanatory view of Oldham coupling. It is a figure explaining the structure of the coupling of a process cartridge and an apparatus main body. It is a figure explaining the structure of the coupling of a process cartridge and an apparatus main body. FIG. 5 is a diagram illustrating an Oldham coupling state when the process cartridge according to the first embodiment is mounted on the image forming apparatus main body. FIG. 5 is a diagram illustrating an Oldham coupling state when the process cartridge according to the first embodiment is mounted on the image forming apparatus main body. FIG. 5 is a diagram illustrating an Oldham coupling state when the process cartridge according to the first embodiment is mounted on the image forming apparatus main body. FIG. 5 is a diagram illustrating an Oldham coupling state when the process cartridge according to the first embodiment is mounted on the image forming apparatus main body. FIG. 5 is a diagram illustrating an Oldham coupling state when the process cartridge according to the first embodiment is mounted on the image forming apparatus main body. FIG. 5 is a diagram illustrating an Oldham coupling state when the process cartridge according to the first embodiment is positioned on the image forming apparatus main body. FIG. 5 is a diagram illustrating an Oldham coupling state when the process cartridge according to the first embodiment is positioned on the image forming apparatus main body. FIG. 5 is a diagram illustrating an Oldham coupling state when the process cartridge according to the first embodiment is positioned on the image forming apparatus main body. FIG. 10 is a diagram illustrating an Oldham coupling state when the process cartridge according to the second embodiment is mounted on the image forming apparatus main body. FIG. 10 is a diagram illustrating an Oldham coupling state when the process cartridge according to the second embodiment is mounted on the image forming apparatus main body. FIG. 10 is a diagram illustrating an Oldham coupling state when the process cartridge according to the second embodiment is mounted on the image forming apparatus main body. FIG. 10 is a diagram illustrating an Oldham coupling state when the process cartridge according to the second embodiment is mounted on the image forming apparatus main body. FIG. 10 is a diagram illustrating an Oldham coupling state when the process cartridge according to the second embodiment is positioned on the image forming apparatus main body. FIG. 10 is a diagram illustrating an Oldham coupling state when the process cartridge according to the second embodiment is positioned on the image forming apparatus main body. FIG. 10 is a diagram illustrating an Oldham coupling state when the process cartridge according to the second embodiment is positioned on the image forming apparatus main body. FIG. 10 is a diagram illustrating an Oldham coupling state when the process cartridge according to the second embodiment is positioned on the image forming apparatus main body. It is a figure explaining the state of Oldham coupling at the time of image formation in a 2nd embodiment. It is a figure explaining the state of Oldham coupling at the time of image formation in a 2nd embodiment. It is a figure which shows the electrophotographic image forming apparatus in 3rd Embodiment. FIG. 10 is a diagram illustrating when a process cartridge according to a third embodiment is mounted on an image forming apparatus main body. FIG. 10 is a diagram illustrating when a process cartridge according to a third embodiment is mounted on an image forming apparatus main body. FIG. 10 is a diagram illustrating when a process cartridge according to a third embodiment is mounted on an image forming apparatus main body. FIG. 10 is a diagram illustrating when a process cartridge according to a third embodiment is mounted on an image forming apparatus main body. FIG. 10 is a diagram illustrating when a process cartridge according to a third embodiment is mounted on an image forming apparatus main body. It is a figure explaining the state of the Oldham coupling at the time of mounting | wearing the image forming apparatus main body with the developing device in 4th Embodiment. It is a figure explaining the state of the Oldham coupling at the time of mounting | wearing the image forming apparatus main body with the developing device in 4th Embodiment. It is a figure explaining the state of the Oldham coupling at the time of mounting | wearing the image forming apparatus main body with the developing device in 4th Embodiment. It is a figure explaining the state of the Oldham coupling at the time of mounting | wearing the image forming apparatus main body with the developing device in 4th Embodiment. It is a figure explaining the state of Oldham coupling when the developing device in 4th Embodiment is positioned to the image forming apparatus main body. It is a figure explaining the state of Oldham coupling when the developing device in 4th Embodiment is positioned to the image forming apparatus main body.

[First Embodiment]
A color electrophotographic image forming apparatus (hereinafter referred to as “image forming apparatus”) according to a first embodiment of the present invention will be described.

(Overall configuration of image forming apparatus)
First, the overall configuration of the image forming apparatus will be described with reference to FIG. FIG. 1 is an overall configuration diagram of the image forming apparatus according to the first embodiment.

  First, an overall configuration of an electrophotographic image forming apparatus (hereinafter referred to as an image forming apparatus) 100 will be described with reference to FIG. As shown in FIG. 1, four detachable process cartridges 7 (7a, 7b, 7c, 7d) are mounted from the front side to the back side of the figure by mounting members (not shown). In FIG. 1, the process cartridge 7 is provided side by side with respect to the horizontal direction in the electrophotographic image forming apparatus main body 100A.

  Each process cartridge 7 includes an electrophotographic photosensitive drum (hereinafter referred to as a photosensitive drum) 1 (1a, 1b, 1c, 1d) and a charging roller 2 (2a, 2b, 2c, 2d) around the photosensitive drum 1. ), Developing roller 25 (25a, 25b, 25c, 25d), and process means such as cleaning member 6 (6a, 6b, 6c, 6d) are integrally disposed. The charging roller 2 uniformly charges the surface of the photosensitive drum 1, and the developing roller 25 develops the latent image formed on the photosensitive drum 1 with toner to make a visible image. The cleaning member 6 removes the developer remaining on the photosensitive drum 1 after transferring the developer image formed on the photosensitive drum 1 to a recording medium.

  A scanner unit 3 is provided below the process cartridge 7 for selectively exposing the photosensitive drum 1 based on image information and forming a latent image on the photosensitive drum 1.

  A cassette 17 containing a recording medium S is mounted at the lower part of the apparatus main body 100A. A recording medium conveying means is provided so as to be conveyed above the apparatus main body A. That is, the feeding roller 18 that separates and feeds the recording medium S in the cassette 17 one by one, the transport roller pair 19 that transports the fed recording medium S, the latent image formed on the photosensitive drum 1 and the recording medium. A registration roller pair 20 for synchronizing with S is provided. Further, an intermediate transfer unit serving as an intermediate transfer unit for transferring a toner image formed on each photosensitive drum 1 (1a, 1b, 1c, 1d) above the process cartridge 7 (7a, 7b, 7c, 7d). A unit 5 is provided.

  The intermediate transfer unit 5 has a driving roller 21, a driven roller 22, a primary transfer roller 23 (23 a, 23 b, 23 c, 23 d) at a position facing the photosensitive drum 1 of each color, and a position facing the secondary transfer roller 24. The intermediate transfer belt 5a is stretched over a roller 87. The intermediate transfer belt 5a circulates so as to face and contact all the photosensitive drums 1 and applies a voltage to the primary transfer roller 23, whereby the primary transfer from the photosensitive drum 1 onto the intermediate transfer belt 5a is performed. I do. The toner on the intermediate transfer belt 5a is transferred to the recording medium S by applying a voltage to the opposing roller 87 and the secondary transfer roller 24 disposed in the intermediate transfer belt 5a.

  When forming an image, each photosensitive drum 1 is rotated, and the photosensitive drum 1 uniformly charged by the charging roller 2 is selectively exposed from the scanner unit 3. Thereby, an electrostatic latent image is formed on the photosensitive drum 1. The latent image is developed by the developing roller 25. Thus, each color developer image is formed on each photoconductive drum 1. In synchronization with this image formation, the registration roller pair 20 conveys the recording medium S to the secondary transfer position where the opposing roller 87 and the secondary transfer roller 24 are in contact with each other with the intermediate transfer belt 5a interposed therebetween. Then, each color developer image on the intermediate transfer belt 5a is secondarily transferred to the recording medium S by applying a transfer bias voltage to the secondary transfer roller 24. As a result, a color image is formed on the recording medium S. The recording medium S on which the color image is formed as described above is heated and pressed by the fixing unit 88 to fix the developer image. Thereafter, the recording medium S is discharged to the discharge unit 90 by the discharge roller 89. The fixing unit 88 is disposed on the upper part of the apparatus main body 100A.

(Process cartridge)
Next, the process cartridge 7 of this embodiment will be described with reference to FIG. FIG. 2 is a main cross section of the process cartridge 7 containing a developer (hereinafter referred to as toner). The process cartridge 7a containing yellow toner, the process cartridge 7b containing magenta toner, the process cartridge 7c containing cyan toner, and the process cartridge 7d containing black toner have the same configuration. .

  The process cartridge 7 is divided into a photosensitive drum 1, a charging roller 2, a drum unit 26 (26a to 26d) including a cleaning member 6, and a developing unit 4 (4a to 4d) having a developing member.

  The photosensitive drum 1 is rotatably attached to the cleaning frame 27 of the drum unit 26 via a bearing (not shown). As described above, the charging roller 2 and the cleaning member 6 are disposed on the circumference of the photosensitive drum 1. Further, the residual toner removed from the surface of the photosensitive drum 1 by the cleaning member 6 falls into the removed toner chamber 27a. Then, by transmitting a driving force of a driving motor (not shown) as a driving source to the drum unit 26, the photosensitive drum 1 is rotationally driven according to an image forming operation. The charging roller bearing 28 is attached to the cleaning frame 27 so as to be movable in the arrow D direction. The charging roller 2 has a shaft 2j rotatably attached to the charging roller bearing 28, and the charging roller bearing 28 is pressurized toward the photosensitive drum 1 by a charging roller pressing member 46.

  The developing unit 4 that is a developing device includes a developing roller 25 and a developing frame 31 that rotate in the direction of arrow B in contact with the photosensitive drum 1. The developing roller 25 is rotatably supported by the developing frame 31 via bearing members 32 (32R, 32L) attached to both sides of the developing frame 31, respectively. Around the developing roller 25, a toner supply roller 34 that rotates in the direction of arrow C in contact with the developing roller 25 and a developing blade 35 for regulating the toner layer on the developing roller 25 are disposed. Further, the toner container 31 a of the developing device frame 31 that is a developer container is provided with a toner conveying member 36 that agitates the accommodated toner and conveys the toner to the toner supply roller 34.

  The developing unit 4 is rotatably coupled to the drum unit 26 about shafts 37R and 37L provided in the bearing members 32R and 32L and fitted in the holes 32Rb and 32Lb. At the time of image formation of the process cartridge 7, the developing unit 4 is biased by the pressure spring 38, and therefore rotates around the shafts 37 </ b> R and 37 </ b> L so that the developing roller 25 is in contact with the photosensitive drum 1. .

(Mechanism for mounting the process cartridge to the image forming apparatus main body)
Next, a mechanism for mounting the process cartridge 7 embodying the present invention to the apparatus main assembly 100A will be described with reference to FIG.

  FIG. 3A is a diagram illustrating a state before the process cartridge 7 is mounted on the apparatus main body 100A. 3A, the process cartridge 7 is mounted (entered) in the direction of arrow E from the opening 82b of the front plate 82 of the apparatus main body 100A. Here, the E direction is the longitudinal direction of the process cartridge 7. The longitudinal direction of the process cartridge 7 is also the axial direction of the photosensitive drum 1 and the axial direction of the developing roller 25. At that time, the guided portion 27b provided integrally with the cleaning frame 27 of the process cartridge 7 is guided in the direction of arrow E while being guided while being placed on the guide portion 81a of the guide member 81 provided on the apparatus main body 100A. It is attached to. The guide member 81 is a mounting member for detachably mounting the process cartridge 7.

  FIG. 3B is a diagram illustrating a state where the process cartridge 7 is mounted up to the rear plate 83 which is the rear plate 83 in the mounting direction. When the process cartridge 7 is mounted in the direction of arrow E, the abutting portion 27c provided integrally with the cleaning frame 27 abuts on the rear plate 83 of the apparatus main body 100A, so that the process cartridge 7 reaches the rear plate 83. It will be in the state of wearing. As a result, the position of the process cartridge 7 in the longitudinal direction is determined. In this state, the process cartridge 7 is not completely positioned on the apparatus main body 100A. That is, the positioning in the vertical direction (direction intersecting the longitudinal direction of the process cartridge 7) is not performed. Further, the photosensitive drum 1 is not in contact with the transfer belt 5 a of the intermediate transfer unit 5.

  FIG. 3c is a diagram illustrating a state in which the process cartridge 7 is completely attached to the apparatus main body 100A. After the process cartridge 7 is mounted up to the rear side plate 83 in the longitudinal direction, the moving members 84R and 84L provided in the apparatus main body 100A are connected to the pressed portions 27Ld and 27Rd provided integrally with the cleaning frame 27 of the process cartridge 7. Press in the direction of arrow F. The moving members 84R and 84L move in conjunction with an opening / closing cover (not shown) provided in the apparatus main body 100A. Here, the opening / closing cover (not shown) opens and closes an opening (not shown) provided in the apparatus main body 100A when the process cartridge 7 is mounted. Then, the positioning portions 27Re and 27Le provided integrally with the cleaning frame body 27 abut against the abutting portion 82a of the front side plate 82 and the abutting portion 83a of the rear side plate 83 of the apparatus main body 100A, respectively. Are positioned in the vertical direction. Thus, the process cartridge 7 is completely positioned on the apparatus main body 100A. In this state, the photosensitive drum 1 and the transfer belt 5a also come into contact with each other.

  That is, the rear side plate 83 against which the abutting portion 27 c abuts is a positioning portion in the longitudinal direction of the process cartridge 7. The abutting portions 82a and 83a against which the positioning portions 27Re and 27Le abut are main body positioning portions for positioning the process cartridge 7 in the vertical direction.

  Further, the moving members 84R and 84L can take a first position (the position shown in FIG. 3a) that allows the process cartridge 7 to enter the apparatus main body 100A. That is, the first position is a position where the moving members 84R and 84L do not protrude from the guide 81a so as not to prevent the process cartridge 7 from entering. At this time, the opening / closing cover (not shown) is in a position to open the opening (not shown). Further, the moving members 84R and 84L are arranged at a second position (FIG. 3c) that presses the process cartridge 7 in a direction crossing the longitudinal direction (entry direction) of the process cartridge 7 in order to position the process cartridge 7 at the main body positioning portion. Position). That is, the moving members 84R and 84L are at positions protruding from the guide 81a. At this time, the open / close cover (not shown) is in a position to close the opening (not shown). That is, when the opening / closing cover (not shown) moves from the open position to the closed position, the moving members 84R and 84L move from the first position to the second position. That is, when the process cartridge 7 shown in FIG. 3A is mounted from the longitudinal direction, the photosensitive drum 1 can be mounted away from the transfer belt 5a, so that the photosensitive drum 1 and the transfer belt 5a are rubbed. There is nothing to do. The moving members 84R and 84L move from the first position to the second position, so that the photosensitive drum 1 can be brought into contact with the transfer belt 5a.

(Supporting structure of developing roller and Oldham coupling in process cartridge)
Next, a configuration using the Oldham coupling 48 as a shaft coupling member and a support configuration of the developing roller 25 in the process cartridge 7 according to the present embodiment will be described with reference to FIGS. 4 to 6. FIG. 4 is a view showing one longitudinal end side of the support portion of the developing roller 25. In FIG. 4, the developing roller shaft 25j of the developing roller 25 is rotatably fitted to the inner periphery of a bearing portion 32Lc provided integrally with the bearing member 32L. Between the rubber roller portion 25g of the developing roller 25 and the bearing portion 32Lc, a regulating roller 47 for regulating the contact amount of the developing roller 25 to the photosensitive drum 1 is rotatably fitted to the developing roller shaft 25j. Is provided. Here, the support structure on the one end side in the longitudinal direction of the developing roller 25 has been described, but the bearing portion is similarly provided integrally with the bearing member on the other end side in the longitudinal direction, and the other end side of the developing roller shaft is rotatably fitted. Match.

  The structure of the Oldham coupling 48 which is the shaft coupling member of this embodiment is demonstrated using FIG.5 and FIG.6. Here, the bearing member 32L is omitted in order to explain the configuration of the Oldham coupling 48.

  In FIG. 5, the Oldham coupling 48 includes a driven side engaging portion 48a, an intermediate engaging portion 48b, and a driving side engaging portion 48c, which are fixed side engaging portions. Here, the driven side engaging portion 48a is fixed to the end portion of the developing roller shaft 25j. As a fixing method, a coupling method using a spring pin or a parallel pin, or as shown in FIG. 5, a cut portion 25c is provided on the end surface of the developing roller shaft 25j, and a hole on the driven side engaging portion 48a side is formed therewith. There is a method of cutting and joining into corresponding shapes. The driving side engaging portion 48 c is rotatably fitted to the engaging portion bearing member 49. Further, on the driving side engaging portion 48c which is an engaging portion, protrusions 48c1 to 48c4 which engage with a main body developing coupling 53 (see FIG. 7) which is a second main body driving force transmitting member of the apparatus main body 100A described later. Are integrally formed. This Oldham coupling 48 allows a deviation between the axis of the main body developing coupling 53 and the axis of the developing roller 25 and transmits the driving rotational force (second driving rotational force) from the apparatus main body 100A to the developing roller 25. .

  In FIG. 6, the configuration of the Oldham coupling 48 will be described in more detail with reference to cross-sectional views. 6A is a cross-sectional view in a direction parallel to the arrow H in FIG. 5, and FIG. 6B is a cross-sectional view in a direction parallel to the arrow G in FIG.

  In FIG. 6a, a rib 48a1 is integrally provided on the driven side engaging portion 48a. The intermediate engagement portion 48b is provided with a groove 48ba1, and the rib 48a1 and the groove 48ba1 are fitted so as to be movable in the direction of arrow G in FIG.

  In FIG. 6b, the drive side engaging portion 48c is integrally provided with a rib 48c6. The intermediate engagement portion 48b is provided with a groove 48bc1, and the rib 48c6 and the groove 48bc1 are fitted so as to be movable in the direction of arrow H in FIG.

  FIG. 7 a is a view showing the configuration of the coupling provided in the process cartridge 7. Projections 48c1 to 48c3 projecting in the axial direction are integrally formed on the end face of the driving side engaging portion 48c of the Oldham coupling 48 provided in the developing unit 4. A centering protrusion 48c4, which is an engaging portion positioning portion for aligning the axis with the main body coupling 53, protrudes in the axial direction from the end face of the driving side engaging portion 48c. A triangular drum coupling 1 c is provided at the tip of the photosensitive drum 1. The guide portion 49b of the engaging portion bearing member 49 is guided by a groove 50a of the side cover 50 fixed to the developing unit 4 with a screw (not shown) so as to be movable in a direction intersecting the axial direction of the developing roller 25. . That is, the driving side engaging portion 48 c is movable in a direction intersecting with the axis 25 of the developing roller 25.

  FIG. 7b is a diagram showing the configuration of the coupling provided in the apparatus main body 100A. In FIG. 7b, a drum drive coupling (main body drum coupling) 66 which is a first main body driving force transmission member for transmitting a driving force from the apparatus main body 100A to the photosensitive drum 1 has a hole 66a having a substantially triangular cross section. Is provided. After the process cartridge 7 is positioned on the main body positioning portions 82a and 83a by the moving members 84R and 84L, the coupling moving mechanism 66b moves in the arrow m direction. As a result, the drum drive coupling 66 moves together with the coupling moving mechanism 66b toward the process cartridge 7 in the axial direction of the photosensitive drum 1. When the phases of the holes 66a of the drum coupling 1c and the drum driving coupling 66 are shifted, the end surface 1c1 of the drum coupling 1c and the end surface 66c of the drum driving coupling 66 are in contact with each other. . At that time, the drum drive coupling 66 retracts in the direction of arrow n against the urging force of the spring 66b1 provided on the moving plate 66b2. When the drum driving coupling 66 rotates and the drum coupling 1c and the hole 66a are in phase, the drum driving coupling 66 is moved in the direction of the arrow r by the biasing force of the spring 66b1, and the coupling 1c and the hole are moved. 66a is engaged. Then, the driving torque (first driving torque) is transmitted to the photosensitive drum 1 by the drum driving coupling 66. That is, the drum coupling 1c is brought into a position where it can be engaged with the drum driving coupling 66 when the process cartridge 7 shown in FIG. 3C is positioned on the main body positioning portions 82a and 83a by the moving members 84R and 84L. Become. Therefore, the drum drive coupling 66 needs to be retracted until the process cartridge 7 is positioned by the main body positioning portions 82a and 83a. Therefore, the above-described coupling moving mechanism 66 becomes necessary.

  On the other hand, the main body developing coupling 53 is simply urged toward the process cartridge 7 by a pressing member (pressing portion) 53c such as a compression spring in a direction parallel to the axis of the developing roller 25. It is. The development roller 25 is provided with an Oldham coupling 48. Therefore, even before the process cartridge 7 shown in FIG. 3B is positioned by the main body positioning portions 82a and 83a, the main body developing coupling 53 and the Oldham coupling 48 can be engaged. That is, when the process cartridge 7 enters the apparatus main body 100 </ b> A, the driving side engaging portion 48 c may be shifted from the axis of the developing roller 25 and positioned at a position where it can engage with the main body developing coupling 53. Therefore, the retracting mechanism in the main body developing coupling 53 does not need to use a coupling moving mechanism like that used in the drum drive coupling 66, and can be configured simply.

  A detailed configuration of the main body development coupling 53 will be described. The main body development coupling 53 is provided with holes 53b1, 53b2, and 53b3. The main body development coupling 53 is urged toward the process cartridge 7 by a pressing member 53c such as a compression spring in a direction parallel to the axis of the development roller 25.

  When the process cartridge 7 enters the apparatus main body 100A and the drive side engaging portion 48c and the main body developing coupling 53 are engaged, the projections 48c1 to 48c3 and the holes 53b1 to 53b3 may not be in phase. In this case, the tips of the protrusions 48c1 to 48c3 come into contact with places other than the holes 53b1 to 53b3, and the main body development coupling 53 moves back in the axial direction against the urging force of the pressing member 53c. However, when the main body development coupling 53 rotates and the projections 48c1 to 48c3 and the holes 53b1 to 53b3 are in phase, the main body development coupling 53 advances by the urging force of the pressing member 53c. The projections 48c1 to 48c3 and the holes 53b1 to 53b3 engage with each other, the centering boss 48c4 and the centering hole 53b4 that is the transmission member positioning part are also engaged, and the axis of the drive side engaging part 48c and the main body developing coupling 53 (Rotation center) matches. When the projections 48c1 to 48c3 and the holes 53b1 to 53b3 are in phase with each other, the protrusions 48c1 to 48c3 are engaged with each other, and the driving rotational force is transmitted to the developing roller 25.

  Here, the driving rotational force with respect to the drum driving coupling 66 and the main body developing coupling 53 is transmitted by a motor (not shown) provided in the apparatus main body 100A. There are a configuration in which one motor is used for each color process cartridge, and a configuration in which the drive is transmitted to several color process cartridges by one motor.

  As described above, the driving force is directly input from the apparatus main body 100A to the developing roller 25 independently of the driving input to the photosensitive drum 1. Therefore, the rotational accuracy of the photosensitive drum 1 can be suppressed from being affected by the rotation of the developing roller 25, and further, the rotational accuracy of the developing roller 25 itself can be improved and the image quality can be improved.

(Oldham coupling operation when the process cartridge is installed in the image forming device)
Next, the operation of the Oldham coupling 48 when the process cartridge 7 embodying the present invention is mounted on the image forming apparatus main body 100A will be described with reference to FIGS. FIG. 8A is a view of the state in which the process cartridge 7 is mounted toward the rear plate 83 in the mounting direction (see FIG. 3A) as viewed from the back in the mounting direction. 8b is a cross-sectional view of FIG. 8a viewed from the longitudinal side surface (arrow V1).

  As shown in FIG. 8b, the axis 53a of the main body developing coupling 53 of the apparatus main body 100A is shifted from the axis 25k of the developing roller 25 of the process cartridge 7 to be mounted. As described above, it is necessary to lower the photosensitive drum 1 and the developing roller 25 so that the photosensitive drum 1 and the transfer belt 5a do not slide when the process cartridge 7 enters the apparatus main body 100A. Because there is. Therefore, the main body developing coupling 53 is provided so that the axis line 25k of the developing roller 25 and the axis line 53a substantially coincide with each other when the process cartridge 7 is positioned on the main body positioning portions 82a and 83a. The drive side engaging portion 48 c is urged by the urging member 54, which is an elastic body, via the engaging portion bearing member 49, and is positioned by the holding portion 27 f provided in the cleaning frame body 27. This is because when the process cartridge 7 is mounted, the axis 48c5 of the driving side engaging portion 48c is placed at a position substantially coincident with the axis 53a so that the driving side engaging portion 48c can be easily engaged with the main body developing coupling 53. It is for arranging. That is, when the process cartridge 7 enters the apparatus main body 100A, the driving side engaging portion 48c is positioned at the holding portion 27f so that the axis 48c5 is closer to the axis 53a of the main body developing coupling 53 than the axis 25k. Is positioned. Here, the distance between the axis 48c5 and the axis 25k of the developing roller 25 is set to D1. Therefore, by positioning the engaging portion 48c on the holding portion 27f, a large guide for engagement is not provided on the engaging portion 48c and the main body developing coupling 53, and the process cartridge 7 and the electrophotographic image forming apparatus 100 can be reduced in size. Can be realized. Here, the biasing member 54 is used as a biasing force for the engaging portion bearing member 49. However, the engaging portion bearing member 49 may be brought into contact with the holding portion 27f by providing the engaging portion bearing member 49 with an elastic portion that can be elastically deformed integrally.

  9A is a view of the state in which the process cartridge 7 is mounted on the apparatus main body 100A up to the rear plate 83 in the mounting direction of the process cartridge 7 (see FIG. 3B) as viewed from the back in the mounting direction. FIG. 9b is a cross-sectional view of FIG. 9a as seen from the longitudinal side surface (arrow V2).

  9A, when the process cartridge 7 is guided by the guide member 81 of the apparatus main body 100A and mounted to the rear side plate 83 in the mounting direction of the process cartridge 7, the process cartridge 7 is still pressed by the moving member 84. Not. For this reason, it is not completely positioned on the apparatus main body 100A, and the photosensitive drum 1 is separated from the transfer belt 5a.

  In this state, as shown in FIG. 9b, when the projections 48c1 to 48c3 and the holes 53b1 to 53b3 are out of phase, the contact portion 49b replaces the holding portion 27f with the main body contact provided in the apparatus main body 100A. Positioning is made in contact with the main body locking member 85 which is a contact portion. When the contact portion 49b is positioned by the main body locking member 85, the contact portion 49b is guided by the inclined surface 85a provided at the tip of the main body locking member 85 to be in the state shown in FIG. 9b. Accordingly, a gap is generated between the contact portion 49b and the holding portion 27f. Here, the driving side engaging portion 48 c is rotatably fitted to the engaging portion bearing member 49. Accordingly, the driving side engaging portion 48 c is positioned on the main body locking member 85 via the engaging portion bearing member 49. Therefore, when the distance between the axis 48c5 here and the axis 25k of the developing roller 25 is D2, D2 is smaller than D1 described above. The main body developing coupling 53 is pushed by the protrusions 48c1 to 48c3 of the driving side engaging portion 48c and is retracted in the arrow J direction (axial direction) in the figure.

  Further, when the process cartridge 7 is mounted up to the rear side plate 83 (see FIG. 3) and the projections 48c1 to 48c3 and the holes 53b1 to 53b3 are in phase with each other as shown in FIG. 9c, the projection 48c4 and the hole 53b4. And the drive side engaging portion 48c is positioned. At that time, the contact portion 49b of the engaging portion bearing member 49 and the main body locking member 85 are separated from each other. Therefore, if the distance between the axis 48c5 here and the axis 25k of the developing roller 25 is D3, D3 is smaller than D1 and D2 described above.

  FIG. 10A is a view of the state in which the process cartridge 7 is pressed by the moving members 84R and 84L and is positioned by the main body positioning portions 82a and 83a (see FIG. 3C) from the back side in the mounting direction. FIG. 10b is a cross-sectional view of FIG. 10a viewed from the side in the longitudinal direction (arrow V3).

  As shown in FIG. 10 a, the cleaning frame 27 of the process cartridge 7 receives a force from the moving member 84 and is urged in the arrow I direction. As a result, the cartridge positioning portion 27g1 contacts the abutting portion 83a of the rear plate of the apparatus main body 100A, the process cartridge 7 is completely positioned by the apparatus main body 100A, and the photosensitive drum 1 and the transfer belt 5a contact each other. In addition, the axis 25k of the developing roller 25 also comes to a position that substantially coincides with the axis 53a of the main body developing coupling 53. Here, the cartridge positioning portion 27g1 is a part of a drum bearing 27g provided on the cleaning frame 27 and rotatably supporting the photosensitive drum 1. Also, is the contact portion 49b of the engagement portion bearing member 49 contacted and locked to the main body locking member 85 (FIG. 10b), the protrusion 48c4 of the drive side engagement portion 48c, and the main body developing coupling 53? The drive side engagement portion 48c is positioned by fitting with the hole 53b4 (FIG. 10c). For this reason, even if the process cartridge 7 moves in the direction of the arrow I, the movement of the drive side engaging portion 48 c is restricted and does not move together with the process cartridge 7. Therefore, the main body locking member 85 is located on the downstream side of the main body developing coupling 53 in the moving direction (arrow I direction) in which the process cartridge 7 moves. Therefore, if the distance between the axis 48c5 and the axis 25k of the developing roller 25 is D4 (see FIG. 10b) and D5 (see FIG. 10c), respectively, D4 and D5 are smaller than the aforementioned D1, D2, and D3. .

  As shown in FIG. 10b, when the projections 48c1 to 48c3 and the holes 53b1 to 53b3 are out of phase, the main body development coupling 53 rotates, so that the projections 48c1 to 48c3 are in phase with the holes 53b1 to 53b3. Fit. Then, the driving side engaging portion 48c and the main body developing coupling 53 are engaged. On the other hand, as shown in FIG. 10c, if the projections 48c1 to 48c3 of the driving side engaging portion 48c are in phase with the holes 53b1 to 53b3 provided in the main body developing coupling 53, the driving side engaging portion 48c and the main body The development coupling 53 is engaged. Then, when the main body developing coupling 53 rotates, a driving rotational force (second driving rotational force) is transmitted to the driving side engaging portion 48c.

  As described above, in the configuration in which the main body positioning portions 82a and 83a are positioned by the moving members 84R and 84L in a direction crossing the direction in which the process cartridge 7 enters, the retraction mechanism of the main body developing coupling 53 is simplified and the image forming apparatus 100 is used. Can be miniaturized.

  Further, it is necessary to provide a large guide for engaging the driving side engaging portion 48c and the main body developing coupling 53 by positioning the driving side engaging portion 48c provided in the Oldham coupling 48 to the holding portion 27f. No. Therefore, the process cartridge 7 and the electrophotographic image forming apparatus 100 can be reduced in size.

  In this embodiment, an example using the Oldham coupling 48 has been described. However, other couplings that have an effect of absorbing rotational fluctuations that occur when the input and output axes (center of rotation) are shifted. (For example, lateral coupling or the like) may be used.

[Second Embodiment]
Next, the operation of the Oldham coupling when the cartridge according to the second embodiment of the present invention is mounted on the image forming apparatus main body will be described with reference to FIGS. Note that the basic configuration of the apparatus of the present embodiment is the same as that of the first embodiment described above, and therefore, a duplicate description is omitted. Here, a configuration that is a feature of the present embodiment will be described. Further, members having the same functions as those of the first embodiment described above are denoted by the same reference numerals.

  11a is a view of the state in which the process cartridge 7 is mounted toward the rear side plate 83 in the mounting direction (see FIG. 3a), as viewed from the back in the mounting direction, and FIG. 11b is a side view in the longitudinal direction (arrow V4). It is sectional drawing seen from ().

    As shown in FIGS. 11a and 11b, the process cartridge 7 is not pressed by the moving member 84 in a state where the process cartridge 7 is being guided and attached to the guide member 81 of the apparatus main body 100A. For this reason, it is not completely positioned in the apparatus main body 100A. Further, in this state, the development unit 4 includes a separation holding member (separation member) 86 for holding the development unit 4 at a separation position in which the development roller 25 is separated from the photosensitive drum 1 in the state of the process cartridge 7 alone. Is provided. As in the first embodiment, the developing unit 4 is urged by a pressure spring (not shown) in a direction in which the developing roller 25 abuts on the photosensitive drum 1 around the shaft 37. However, since the separation holding member 86 is engaged with the hole 27e provided on the side surface of the cleaning frame 27, the developing unit 4 is rotated in the direction of the arrow L about the shaft 37 and held in the separation position. Yes. The position of the separation holding member 86 at this time is set as an engagement position.

  However, the engaging portion bearing member 49 is urged by the urging member 54 in the crossing direction (the direction of arrow I in the figure) with respect to the axis 25k of the developing roller 25. Therefore, the contact portion 49b of the engagement portion bearing member 49 comes into contact with the holding portion 27f provided on the cleaning frame 27 of the process cartridge 7, and the position of the engagement portion bearing member 49 is determined. For this reason, the axis (rotation center) 48c5 of the driving side engaging portion 48c and the axis 25k of the developing roller are arranged at a shifted position. As in the first embodiment, the photosensitive drum 1 and the developing roller 25 are lowered so that the photosensitive drum 1 and the transfer belt 5a do not slide when the process cartridge 7 enters the apparatus main body 100A. It is necessary to keep it. Therefore, as in the first embodiment, when the process cartridge 7 is positioned on the main body positioning portions 82a and 83a, the main body developing coupling 53 is provided so that the axis 25k of the developing roller 25 and the axis 53a substantially coincide with each other. It has been.

  The holding portion 27f is provided on the cleaning frame 27 to which the photosensitive drum 1 is attached, and a contact portion 49b is in contact with the holding portion 27f and positioned. For this reason, the engaging portion bearing member 49 is positioned with high positional accuracy with respect to the photosensitive drum 1 mounted with high positional accuracy with respect to the apparatus main body 100A. That is, in this state, as shown in FIG. 11b, if the process cartridge 7 is further advanced, it substantially coincides with the axis 53a so that the drive side engaging portion 48c can be easily engaged with the main body developing coupling 53. This is because the axis 48b5 of the driving side engaging portion 48c is disposed at the position. That is, when the process cartridge 7 enters the apparatus main body 100A, the driving side engaging portion 48c is positioned at the holding portion 27f so that the axis 48c5 is closer to the axis 53a of the main body developing coupling 53 than the axis 25k. Is positioned. Here, the distance between the axis 48c5 and the axis 25k of the developing roller 25 is set to S1. Then, by positioning the engaging portion 48c on the holding portion 27f, a large guide for engaging the engaging portion 48c and the main body developing coupling 53 is not provided, and the process cartridge 7 and the electrophotographic image forming apparatus 100 can be reduced in size. Can be realized.

  12A is a view of the state in which the process cartridge 7 is mounted until it abuts against the rear plate 83 in the mounting direction (see FIG. 3B), as viewed from the back in the mounting direction. 12b is a cross-sectional view of FIG. 12a as viewed from the side in the longitudinal direction (arrow V5).

  In the state shown in FIGS. 12a and 12b, the moving member 84 is not pressed. For this reason, the process cartridge 7 is not positioned by the main body positioning portions 82a and 83a of the apparatus main body 100A, and the photosensitive drum 1 is in a state of being separated from the transfer belt 5a. At this time, the axial line 53a of the main body developing coupling 53 and the axial line 25k of the developing roller 25 are shifted from each other.

  In this state, as shown in FIG. 12b, when the projections 48c1 to 48c3 and the holes 53b1 to 53b3 are out of phase, the contact portion 49b contacts the main body locking member 85 instead of the holding portion 27f. Positioned. When the contact portion 49b is positioned by the main body locking member 85, the contact portion 49b is guided by the inclined surface 85a provided at the tip of the main body locking member 85 to be in the state shown in FIG. Therefore, the contact part 49b is separated from the holding part 27f. Here, the driving side engaging portion 48c of the Oldham coupling 48 is rotatably fitted to the engaging portion bearing member 49. Accordingly, the driving side engaging portion 48 c is positioned on the main body locking member 85 via the engaging portion bearing member 49. Therefore, when the distance between the axis 48c5 here and the axis 25k of the developing roller 25 is S2, S2 is smaller than S1 described above.

  The main body developing coupling 53 is pushed by the protrusions 48c1 to 48c3 of the driving side engaging portion 48c and is retracted in the arrow J direction (axial direction) in the figure.

  Further, when the process cartridge 7 is mounted up to the rear side plate 83 (see FIG. 3), the phases of the projections 48c1 to 48c3 and the holes 53b1 to 53b3 are the same as those in FIG. .

Further, as shown in FIG. 12B, the apparatus main body 100A is provided with a main body releasing member 87 that comes into contact with the separation holding member 86 when the process cartridge 7 is mounted on the apparatus main body 100A in the longitudinal direction. Then, before the process cartridge 7 is mounted on the apparatus main body 100A and positioned on the main body positioning portions 82b and 83a, the main body release member 87 contacts the separation holding member 86, so that the separation holding member 86 and the hole 27e are engaged. Is configured to cancel. The position of the separation holding member 86 at this time is set as a release position. When the spacing member 86 is released, the developing unit 4 moves to the contact position, and the developing roller 25 can come into contact with the photosensitive drum 1. However, in a state where the normal process cartridge 7 is mounted on the apparatus main body 100A, the separation mechanism 91 provided on the apparatus main body 100A is disposed at a position where the separation mechanism 91 contacts the force receiving portion 31b of the developing device frame 31. Therefore, even if the process cartridge 7 is mounted on the apparatus main body 100A and the separation holding member 86 is released, the developing roller 25 does not come into contact with the photosensitive drum 1.

  FIG. 13A is a view of the state in which the process cartridge 7 is pressed by the moving member 84 and is positioned by the main body positioning portions 82a and 83a on the apparatus main body 100A as viewed from the back in the mounting direction. FIG. 13b is a cross-sectional view of FIG. 13a viewed from the longitudinal side surface (arrow V6).

  As shown in FIG. 13 a, the cleaning frame 27 of the process cartridge 7 receives a force from the moving member 84 and is urged in the direction of arrow I. As a result, the cartridge positioning portion 27g1 contacts the abutting portion 83a of the rear plate of the apparatus main body 100A, the process cartridge 7 is positioned by the apparatus main body 100A, and the photosensitive drum 1 and the transfer belt 5a contact each other. Here, the cartridge positioning portion 27g1 is a part of a drum bearing 27g provided on the cleaning frame 27 and rotatably supporting the photosensitive drum 1. Further, the abutting portion 49b of the engaging portion bearing member 49 is abutted and locked to the main body locking member 85, or provided on the protrusion 48c4 provided on the driving side engaging portion 48c and the main body developing coupling 53. The drive-side engagement portion 48c is positioned by fitting with the formed hole 53b4. For this reason, even if the process cartridge 7 moves in the direction of arrow I, the drive side engaging portion 48c is held at the position of FIG. 12 and does not move together with the process cartridge 7. Therefore, the main body locking member 85 is positioned on the downstream side of the main body developing coupling 53 in the moving direction (arrow I direction) in which the process cartridge 7 moves. If the distance between the axis 48c5 here and the axis 25k of the developing roller 25 is S3, S3 is smaller than S1 and S2 described above.

  Further, the force receiving portion 31b provided in the developing unit 4 is also maintained in the state where the force is received from the separating mechanism 91 in the direction of the arrow N, so that the developing unit 4 is spaced apart from the photosensitive drum 1 by the developing roller 25. Maintained.

  FIG. 14A is a view of the cartridge in which the developing unit 4 is rotated by the operation of the separation mechanism 91 and the developing roller 25 is moved to the contact position where the developing roller 25 contacts the photosensitive drum 1 as viewed from the back in the mounting direction. FIG. 14B is a cross-sectional view of FIG. 14A as viewed from the longitudinal side surface (arrow V7).

  As shown in FIG. 14A, since the separation mechanism 91 moves in the direction of arrow P and separates from the force receiving portion 31b of the development unit 4, the development unit 4 is driven by the shaft 37 by the force of the pressure spring 38 (see FIG. 2). Is rotated in the direction of the arrow Q about the center. Then, as shown in FIG. 14b, the developing unit 4 moves to a contact position where the photosensitive drum 1 and the developing roller 25 are in contact with each other. In addition, the axis 25k of the developing roller 25 also comes to a position that substantially coincides with the axis 53a of the main body developing coupling 53. If the distance between the axis 48c5 and the axis 25k of the developing roller 25 is S4, S4 is smaller than S1, S2, and S3 described above.

  Next, FIG. 15A is a diagram illustrating a state in which the process cartridge 7 is viewed from the back in the mounting direction during image formation. 15b is a cross-sectional view of FIG. 15a viewed from the longitudinal side surface (arrow V8).

  Here, when the projections 48c1 to 48c3 and the holes 53b1 to 53b3 are out of phase, the main body development coupling 53 is rotated so that the projections 48c1 to 48c3 are in phase with the holes 53b1 to 53b3. Therefore, the main body developing coupling 53 and the driving side engaging portion 48c are engaged, and the driving rotational force (second driving rotational force) of the apparatus main body 100A is transmitted to the developing roller 25. In this state, the projection 48c5 provided integrally with the driving side engaging portion 48c and the hole 53b4 provided in the main body developing coupling 53 are fitted, and the axis 53a of the main body developing coupling 53 and the axis of the driving side engaging portion 48c. (Rotation center) 48c5 matches. Similarly, the axis (rotation center) 25k of the developing roller 25 substantially coincides with the axis 53a. Then, the contact portion 49 b of the engagement portion bearing member 49 is in a state of being separated from the main body locking portion 85.

  As described above, in this embodiment, in addition to the effects of the first embodiment, even if the process cartridge 7 is mounted in a state where the photosensitive drum and the developing roller 25 are separated from each other, the shaft coupling member 48 can be smoothly installed. The engaging portion 48c and the main body developing coupling 53 are engaged with each other, so that the mountability is improved.

[Third Embodiment]
(Separation mechanism when re-installing the process cartridge)
Next, a separation mechanism when the process cartridge 7 once taken out from the apparatus main body 100A is mounted again on the apparatus main body 100A will be described. Note that the basic configuration of the apparatus and the like of this embodiment is the same as that of the first embodiment described above, and thus a duplicate description is omitted. Here, a configuration that is a feature of this embodiment will be described. Further, members having the same functions as those of the first embodiment described above are denoted by the same reference numerals.

  In the process cartridge 7 taken out from the apparatus main body 100A, the separation holding member 86 is released from the hole 27e of the cleaning frame 27 as shown in FIGS. Therefore, the developing unit 4 is in the contact position, and the photosensitive drum 1 and the developing roller 25 are in contact with each other. Further, when the process cartridge 7 is removed from the apparatus main body 100A, the image forming operation of the electrophotographic image forming apparatus 100 is completed. Therefore, as shown in FIG. 13, the separation mechanism 91 is located at a position where the separation unit 91 contacts the separation force receiving portion 31b in order to place the developing unit 4 in the separation position. With the separation mechanism 91 in this state, the process cartridge 7 is removed from the apparatus main body 100A, and the developing unit 4 returns to the contact position. However, when the process cartridge 7 is attached to the apparatus main body 100A again in this state, the separation force receiving portion 31b of the developing unit 4 located at the contact position hits the side surface of the separation mechanism 91, and the process cartridge 7 contacts the apparatus main body 100A. It cannot be installed. In order to prevent this, it is necessary to move the developing unit 4 to the separation position in advance when the removed process cartridge 7 is remounted.

  The configuration will be described with reference to FIGS. As shown in FIGS. 16 and 17, the apparatus main body 100 </ b> A is provided with a mounting opening 87 for mounting the process cartridge 7. The apparatus main body 100A is provided with a separation guide portion 92 that comes into contact with a protruding portion 31d provided integrally with a separation force receiving portion 31b provided in the developing unit 4 of the process cartridge 7.

    As shown in FIG. 18A, before the process cartridge 7 enters the apparatus main body 100A, the developing unit 4 is in the contact position, and the photosensitive drum 1 and the developing roller 25 are in contact with each other. When the process cartridge 7 is mounted on the apparatus main body 100A as shown in FIG. 18b, first, the guide portion 27b provided integrally with the cleaning frame 27 is guided by the main body guide member 81 provided on the apparatus main body 100A. Then, the protruding portion 31 d provided on the developing device frame 31 comes into contact with the chamfered portion 92 a of the separation guide portion 92. When the process cartridge 7 is further advanced, the developing unit 4 rotates in the arrow J direction with the back bearing member 15 as the rotation center as shown in FIG. 18c. Then, the developing unit 4 moves to the separation position indicated by the arrow K, and the developing roller 25 is separated from the photosensitive drum 1. When the process cartridge 7 is positioned on the main body of the image forming apparatus 100, the separation force receiving portion 31b is in contact with the separation mechanism 91 disposed on the downstream side in the mounting direction of the separation guide portion 92 as shown in FIG. become. At that time, the developing unit 4 is in the separated position, and the developing roller 25 can be mounted on the main body of the image forming apparatus 100 while maintaining the separated state from the photosensitive drum 1. In this case, the force receiving escape portion 31 e provided on the upstream side of the force receiving portion 31 b in the mounting direction of the process cartridge 7 has a shape that does not interfere with the mounting guide portion 84. This is to allow the developing unit 4 to move to the contact position without interfering with the separation guide portion 92.

  As described above, in the present embodiment as well as the second embodiment, in addition to the effects of the first embodiment, even if the process cartridge 7 is mounted in a state where the photosensitive drum 1 and the developing roller 25 are separated from each other, the embodiment is smoothly performed. The drive side engaging portion 48c and the main body developing coupling 53 are engaged with each other, so that the mountability is improved.

[Fourth Embodiment]
In the above-described embodiment, the case where the process cartridge 7 is mounted on the apparatus main body 100A is illustrated. However, the present invention is also good suitable when the detachable only the developing device to the apparatus main body 100A.

  Next, as a fourth embodiment, the operation of Oldham coupling when the developing device 4 is mounted on the apparatus main body 100A will be described with reference to FIGS. Note that the basic configuration of the apparatus and the like of this embodiment is the same as that of the first embodiment described above, and thus a duplicate description is omitted. Here, a configuration that is a feature of this embodiment will be described. Further, members having the same functions as those of the first embodiment described above are denoted by the same reference numerals.

  20A is a diagram illustrating a state before the developing device 4 is mounted on the apparatus main body 100A from the longitudinal direction of the developing device 4. FIG. 20b is a cross-sectional view of FIG. 20a as viewed from the longitudinal side surface (arrow V9).

  20a and 20b, the driving side engaging portion 48c is urged by the urging member 54 via the engaging portion bearing member 49. The drive side engaging portion 48 c is positioned by the holding portion 31 f provided on the developing device frame 31 via the engaging portion bearing member 49. Therefore, as in the case of the first embodiment, even before the developing device 4 is positioned, the Oldham coupling 48 is in a position where it can engage with the main body developing coupling 53. This is because it is necessary to lower the developing roller 25 so that the developing roller 25 and the photosensitive drum 1 do not slide when the developing device 4 enters the apparatus main body 100A. That is, when the developing device 4 enters the apparatus main body 100A, the driving side engaging portion 48c is held by the holding portion 31f so that the axis 48c5 is closer to the axis 53a of the main body developing coupling 53 than the axis 25k. Is positioned. Then, by positioning the engaging portion 48c on the holding portion 31f, a large guide for engagement is not provided on the engaging portion 48c and the main body developing coupling 53, and the developing device 4 and the electrophotographic image forming apparatus 100 can be reduced in size. Can be realized. Here, the distance between the axis 48c5 and the axis 25k of the developing roller 25 is set to L1.

  FIG. 21A is a diagram illustrating a state in which the developing device 4 is mounted to the apparatus main body 100A up to the rear side plate (not shown) in the mounting direction of the developing device. FIG. 21b is a cross-sectional view of FIG. 21a as viewed from the longitudinal side surface (arrow V10).

  As shown in FIG. 21a, when the developing device 4 is guided by the guide member 81 of the apparatus main body 100A and is mounted to the rear side plate (not shown) in the mounting direction of the developing device 4, it is moved by the moving member 84 of the apparatus main body 100A. It is not pressed. Therefore, the developing roller 25 is separated from the photosensitive drum 1.

  In this state, as shown in FIG. 21b, when the projections 48c1 to 48c3 and the holes 53b1 to 53b3 are out of phase, the contact portion 49b replaces the holding portion 31f and the main body provided in the apparatus main body 100A. Positioning is made in contact with the locking member 85. When the contact portion 49b is positioned by the main body locking member 85, the contact portion 49b is guided by the inclined surface 85a provided at the tip of the main body locking member 85 to be in the state shown in FIG. 21b. Here, the driving-side engaging portion 48 c of the Oldham coupling is rotatably fitted to the engaging portion bearing member 49. Accordingly, the driving side engaging portion 48 c is positioned on the main body locking member 85 via the engaging portion bearing member 49. Therefore, when the distance between the axis 48c5 here and the axis 25k of the developing roller 25 is L2, L2 is smaller than L1 described above. Then, the main body developing coupling 53 is pushed by the driving side engaging portion 48c and is retracted in the direction of arrow J (axial direction) in the drawing.

  Further, when the projections 48c1 to 48c3 and the holes 53b1 to 53b3 are in phase, the projection 48c4 provided on the driving side engaging portion 48c and the hole 53b4 provided on the main body developing coupling 53 are fitted. Thus, the driving side engaging portion 48c is positioned. At that time, the contact portion 49b of the engaging portion bearing member 49 and the main body locking member 85 are separated from each other.

  FIG. 22A is a diagram illustrating a state in which the developing device is pressed by the moving member 84 and is positioned on the apparatus main body 100A. And FIG. 22b is a figure which looked at the state which looked at FIG. 22a from the longitudinal direction side surface (arrow V11).

  As shown in FIG. 22 a, when the developing frame 31 of the developing device 4 receives a force from the moving member 84 and is urged in the direction of arrow I, the regulating rollers 47 provided at both ends of the developing roller 25 are Abuts on the photosensitive drum 1. The developing device 4 is completely positioned on the apparatus main body 100A, and the developing roller 25 and the photosensitive drum 1 come into contact with each other. In addition, the axis 25k of the developing roller 25 also comes to a position that substantially coincides with the axis 53a of the main body developing coupling 53. Here, when the developing device moves in the direction of arrow I, the abutting portion 49b of the engaging portion bearing member 49 abuts on and is engaged with the main body engaging member 85, or the projection 48c4 and the hole 53b4 are fitted. Accordingly, the driving side engaging portion 48 c is positioned on the main body developing coupling 53. For this reason, even if the developing device 4 moves in the direction of arrow I, the driving side engaging portion 48c is held at the position of FIG. 21 and does not move together with the developing device 4. Therefore, the main body locking member 85 is positioned on the downstream side of the main body developing coupling 53 in the moving direction in which the developing device 4 moves. Therefore, when the distance between the axis 48c5 here and the axis 25k of the developing roller 25 is L3, L3 is smaller than L1 and L2 described above.

  Here, when the phases of the projections 48c1 to 48c3 and the holes 53b1 to 53b3 are not in phase, the main body development coupling 53 rotates, so that the coupling projections 48c1 to 48c3 and the holes 53b1 to 53b3 as shown in FIG. 22b. Are in phase. Then, the driving side engaging portion 48c and the main body developing coupling 53 are engaged. On the other hand, if the projections 48c1 to 48c3 of the driving side engaging portion 48c are in phase with the holes 53b1 to 53b3 provided in the main body developing coupling 53, the driving side engaging portion 48c and the main body developing coupling 53 are engaged. doing. Then, the driving torque is transmitted as the main body developing coupling 53 rotates.

  As described above, in the configuration in which the main body positioning portions 82a and 83a are positioned by the moving members 84R and 84L in a direction crossing the direction in which the developing device 4 enters, the retracting mechanism of the main body developing coupling 53 is simplified, and the electronic The photographic image forming apparatus 100 can be reduced in size.

  Further, by positioning the engaging portion 48c provided on the shaft coupling member 48 to the holding portion 31f, a large guide for engaging the engaging portion 48c and the main body developing coupling 53 is not provided, and the developing device 4 and Miniaturization of the electrophotographic image forming apparatus 100 can be realized.

  In addition, although the example using Oldham coupling was described in this embodiment, other couplings that have an effect of absorbing rotational fluctuations that occur when the input side and output side axes (center of rotation) are deviated ( For example, lateral coupling may be used.

DESCRIPTION OF SYMBOLS 1 ... Photosensitive drum 1c ... Drum coupling 4 ... Developing unit 5 ... Intermediate transfer unit 5a ... Intermediate transfer belt 7 ... Process cartridge 25 ... Developing roller 25k ... Axis 26 ... Drum unit 27 ... Cleaning frame 27Ld, 27Rd ... Pressed part 27Re, 27Le ... positioning part 27b ... guided part 27c ... abutting part 27g ... positioning part 27f ... holding part 31 ... developing frame 48a ... driven side engaging part 48a1 ... rib 48b ... intermediate engaging part 48ba1 ... groove 48c ... Driving side engaging portion 49... Engaging portion bearing member 53... Main body developing coupling 53b1, 53b2, 53b3... Hole 54 .. biasing member 66 .. drum driving coupling 66a ... hole 84R, 84L ... moving member 100.

Claims (3)

A photosensitive drum;
A developing roller for developing the electrostatic latent image formed on the photosensitive drum;
The driven part fixed to one end side in the axial direction of the developing roller and movable with respect to the driven part in a direction crossing the axial direction of the developing roller while maintaining engagement with the driven part A drive unit for rotating the developing roller, and an intermediate unit and a driving unit movable in a direction crossing the axial direction of the developing roller with respect to the intermediate unit while maintaining engagement with the intermediate unit. A coupling part that receives force,
A process cartridge that is detachable from the image forming apparatus main body, and
A main body driving unit that engages with the driving unit and applies a driving force to the driving unit ;
In an image forming apparatus for forming an image on a recording material,
Arranged a first position for forming an image on the photosensitive drum, a position retracted from said first position, and a second position for mounting and dismounting the process cartridge in the image forming apparatus, said process cartridge the moving mechanism to possess,
The image forming apparatus , wherein the moving mechanism moves the photosensitive drum to the first position and the second position in a state where the driving unit and the main body driving unit are engaged with each other. A belt member that is in contact with the photosensitive drum and carries a toner image transferred from the photosensitive drum;
The image forming apparatus according to claim 1 , wherein the photosensitive drum and the belt member are in contact with each other at the first position, and the photosensitive drum is separated from the belt member at the second position .   The image forming apparatus according to claim 1, wherein the moving mechanism moves the photosensitive drum from the second position to the first position by applying an urging force to the process cartridge. .

Images