JP2005338775A - Process cartridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform operation of contacting and parting of a photoreceptor drum and a developing roller with good accuracy. <P>SOLUTION: The process cartridge 7 attachable and detachable to and from an apparatus main body A provided with a cam member 8 capable of taking a first position and a second position retreated from the first position has a cleaning frame 51 which supports a photoreceptor drum 1, a developing frame 45 which supports a developing roller 40, an entering portion which is disposed on one end side of the developing frame 45 in the longitudinal direction of the photoreceptor drum 1 and into which at least a portion of the cam member 8 enters in the longitudinal direction and which is disposed downstream of the shaft 41e with respect to the mounting direction when the process cartridge 7 is mounted on the apparatus main body A, and a cam engaging portion which receives the force for parting the photoreceptor drum 1 and the developing roller 40 from the cam member 8 by abutting on the cam member 8 and is disposed downstream with respect to the entering portion when the cam member 8 exists in the first position. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a process cartridge.

  Here, the electrophotographic image forming apparatus forms an image on a recording medium (paper, OHP sheet, cloth, etc.) 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 developing means as process means and an electrophotographic photosensitive drum are integrally formed into a cartridge that can be attached to and detached from the main body of the electrophotographic image forming apparatus.

  2. Description of the Related Art Conventionally, in an electrophotographic image forming apparatus, an electrophotographic photosensitive drum (hereinafter referred to as “photosensitive drum”) and process means acting on the photosensitive drum are integrally formed into a cartridge, and this cartridge is used as an image forming apparatus. A process cartridge system that is detachable from the main body is employed. According to this process cartridge system, the maintenance of the apparatus can be performed by the operator himself without depending on the service person. For this reason, this process cartridge system is widely used in electrophotographic image forming apparatuses.

  As the above-described process cartridge (hereinafter referred to as a cartridge), for example, a process cartridge using a contact developing system in which a photosensitive drum and a developing member that performs development in contact with the photosensitive drum are integrated is known. It has been.

  In this method, the developing roller and the photosensitive drum maintain a predetermined contact pressure during image formation. Therefore, the developing roller is urged against the photosensitive drum.

  Therefore, when image formation is not performed, the toner on the developing roller adheres to the photosensitive drum. Further, this toner may adhere to the recording medium. This may cause the recording medium to become dirty.

  In the contact developing type cartridge, the developing roller is always urged to the photosensitive drum. Therefore, when the cartridge is mounted on the apparatus main body, the elastic layer of the developing roller may be deformed if it is not used for a long time. As a result, there is a possibility that image unevenness may occur during development.

  In view of this, an image forming apparatus has been proposed that can take a state in which the photosensitive drum and the developing roller are in contact with each other and a state in which the photosensitive drum is not in contact with the developing roller (see Patent Document 1).

In addition, a first housing provided with a photosensitive drum and a second housing provided with a developing roller are provided to be rotatable about a support shaft. Then, during non-image formation, the developing roller is separated from the photosensitive drum. During image formation, the developing roller is brought into contact with the photosensitive drum. A color image forming apparatus having such a configuration has been proposed (see Patent Document 2).
US Pat. No. 6,389,243 JP 2001-337511 A

  The present invention has been made in view of the above-described prior art, and an object of the present invention is to provide a process cartridge that realizes miniaturization of an electrophotographic image forming apparatus main body.

  Another object of the present invention is to provide a process cartridge that can perform the contact and separation operations of the electrophotographic photosensitive drum and the developing roller in a space-saving manner.

  Another object of the present invention is to provide a process cartridge capable of accurately performing contact and separation operations between an electrophotographic photosensitive drum and a developing roller.

  Another object of the present invention is a process in which at least a part of a cam member provided in the apparatus main body can enter the process cartridge when the process cartridge is mounted in the electrophotographic image forming apparatus main body. It is to provide a cartridge.

In order to achieve the above object, the present invention provides:
A process cartridge attachable to the electrophotographic image forming apparatus main body,
An electrophotographic photosensitive drum;
A developing roller for developing the electrostatic latent image formed on the electrophotographic photosensitive drum in contact with the electrophotographic photosensitive drum;
A cartridge frame,
A first recess recessed inwardly in the longitudinal direction of the cartridge frame at the end in the longitudinal direction of the electrophotographic photosensitive drum, and one end in the horizontal direction when the process cartridge is attached to the apparatus main body And a first recess having an open upper portion when the process cartridge is attached to the apparatus main body,
A second recess recessed inwardly in the longitudinal direction of the cartridge frame at the end in the longitudinal direction, the other end in the horizontal direction when the process cartridge is attached to the apparatus main body and the process cartridge; A second recess having an open upper part when attached to the apparatus body,
A synthetic recess formed by a virtual first recess when the first recess is moved by a predetermined distance in a predetermined direction and a second recess is a member that acts on the process cartridge provided in the apparatus main body. It has a shape that allows intrusion.

  As described above, according to the present invention, the main body of the electrophotographic image forming apparatus can be reduced in size, and the operation of contacting and separating the electrophotographic photosensitive drum and the developing roller can be performed in a small space.

  Further, the contact and separation operations of the electrophotographic photosensitive drum and the developing roller can be performed with high accuracy.

The best mode for carrying out the present invention will be exemplarily described below with reference to the drawings and examples. However, the materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention only to those unless otherwise specified. Further, the materials, shapes, etc. of the members once described in the following description are the same as those in the first description unless otherwise described.

  In the following description, the longitudinal direction of the cartridge refers to a direction that intersects with the mounting direction in which the cartridge is mounted to the apparatus main body (substantially orthogonal direction, longitudinal direction of the electrophotographic photosensitive drum, rotational axis direction of the developing roller). is there. Further, the upper surface of the cartridge is a surface located above in a state where the cartridge is mounted on the apparatus main body, and the lower surface is a surface located below.

(Overall configuration of electrophotographic image forming apparatus)
First, the overall configuration of the electrophotographic image forming apparatus according to the present embodiment will be described with reference to FIG. FIG. 1 is a cross-sectional view of a color electrophotographic image forming apparatus according to this embodiment. FIG. 3 is an internal perspective view thereof.

  The electrophotographic image forming apparatus (hereinafter referred to as “image forming apparatus”) A has four sets of cartridge mounting means (70Ra to 70Rd, 70La to 70Ld, 71Ra) arranged in parallel in the vertical direction (the height direction of the image forming apparatus A). 71Rd, 71La-71Ld, 34a-34h). Each of the cartridges 7 (7a to 7d) includes one electrophotographic photosensitive drum (hereinafter referred to as "photosensitive drum") 1 (1a to 1d) (FIGS. 1 and 3).

  The photosensitive drum 1 is driven to rotate counterclockwise (FIG. 1) by driving means (not shown). Around the photosensitive drum 1, in order according to the rotation direction, a charging roller 2 (2a to 2d) as charging means for uniformly charging the surface of the photosensitive drum 1, and a laser beam is irradiated on the basis of image information. A scanner unit 3 (3 a to 3 d) that forms an electrostatic latent image on the drum 1, a developing unit 4 (4 a to 4 d) that develops the electrostatic latent image using toner that is a developer, and a photosensitive drum 1. A transfer unit 5 for transferring the formed toner image to the recording medium S and a cleaning blade 6 (6a to 6d) as a cleaning unit for removing the toner remaining on the surface of the photosensitive drum 1 after the transfer are arranged. Here, the photosensitive drum 1, the charging roller 2, the developing unit 4, the blade 6, and the like are provided in the cartridge 7.

  The photosensitive drum 1 has an organic photoconductive layer (OPC photosensitive member) coated on the peripheral surface of an aluminum cylinder. Both ends of the photosensitive drum 1 are rotatably supported by support members. One end of the photosensitive drum 1 in the longitudinal direction has a driving force transmission member (not shown) that transmits a driving force from a driving motor (not shown). As a result, the photosensitive drum 1 is driven to rotate counterclockwise.

  The charging roller 2 is a conductive roller. Then, the roller 2 is brought into contact with the surface of the photosensitive drum 1. Then, a charging bias voltage is applied to the roller 2. Thereby, the surface of the photosensitive drum 1 is uniformly charged.

  The scanner unit 3 is disposed in a substantially horizontal direction with respect to the photosensitive drum 1. The polygon mirror 9 (9a to 9d) is irradiated with image light corresponding to the image signal by a laser diode (not shown). This mirror 9 is rotated by a scanner motor (not shown). The image light reflected by the mirror 9 selectively exposes the surface of the charged photosensitive drum 1 through the imaging lens 10 (10a to 10d). As a result, an electrostatic latent image corresponding to the image signal is formed on the photosensitive drum 1.

As shown in FIG. 2, the developing unit 4 (4 a to 4 d) includes a toner container 41 (41 to 41 d) that is a second frame that stores toner, and a developing frame 45 that is a second frame. . The unit 4a stores yellow toner in the toner container 41a. Similarly, the unit 4b contains magenta color, the unit 4c contains cyan, and the unit 4d contains black toner.

  The toner is sent to the toner supply roller 43 by the toner transport mechanism 42 in the toner container 41. The toner is applied to the peripheral surface of the developing roller 40 by the toner supply roller 43 and the developing blade 44 pressed against the peripheral surface of the developing roller 40 as a developing member. In addition, a charge is applied to the applied toner.

  Then, a developing bias is applied to the developing roller 40. As a result, the electrostatic latent image formed on the photosensitive drum 1 is developed with toner. The developing roller 40 is disposed to face the photosensitive drum 1.

  On the other hand, the image forming apparatus main body A has a transfer belt 11 that circulates and contacts all the photosensitive drums 1a to 1d. The transfer belt 11 is a film-like member. Then, the recording medium S is conveyed to the transfer position by the transfer belt 11. Then, the toner image formed on the photosensitive drum 1 at the transfer position is transferred to the recording medium S.

  The transfer roller 12 (12a to 12d) is in contact with the inside of the transfer belt 11. The transfer roller 12 is provided side by side at a position facing the four photosensitive drums 1 (1a to 1d) with the transfer belt 11 therebetween. Then, a positive charge is applied to the recording medium S via the transfer belt 11 by the transfer roller 12. As a result, the toner image formed on the photosensitive drum 1 is transferred to the recording medium S. The transfer belt 11 is stretched by four rollers, that is, a driving roller 13, driven rollers 14a and 14b, and a tension roller 15, and rotates (in the direction of arrow r1). Thereby, the transfer belt 11 circulates and moves. Then, the toner image is transferred while the recording medium S is conveyed from the driven roller 14a side to the driving roller 13 side.

  The feeding unit 16 feeds and transports the recording medium S to the image forming unit. A plurality of recording media S are stored in the feeding cassette 17. At the time of image formation, the feeding roller 18 and the registration roller pair 19 rotate according to the image forming operation. Thus, the recording medium S in the cassette 17 is separated and fed one by one. Then, the leading edge of the recording medium S hits the registration roller pair 19 and stops temporarily. The recording medium S is fed to the transfer belt 11 by the registration roller pair 19 in synchronization with the rotation of the transfer belt 11 and the toner image.

  The fixing unit 20 fixes the toner images of a plurality of colors transferred to the recording medium S.

  The image forming operation is as follows. First, the cartridges 7 (7a to 7d) are sequentially driven in accordance with the image formation timing. Then, the photosensitive drum 1 (1a to 1d) is rotationally driven in accordance with the drive. Then, the scanner units 3 corresponding to the respective cartridges 7 are sequentially driven. By this driving, the charging unit 2 applies a uniform charge to the peripheral surface of the photosensitive drum 1. The unit 3 exposes the peripheral surface of the photosensitive drum 1 in accordance with the image signal. Thereby, an electrostatic latent image is formed on the peripheral surface of the photosensitive drum 1. The developing roller 40 develops the electrostatic latent image.

  As described above, the toner images on the photosensitive drums 1 are sequentially transferred onto the recording medium S by the electric field formed between the photosensitive drums 1 and the transfer rollers 12. The recording medium S on which the four color toner images are transferred is separated from the transfer belt 11 by the curvature of the driving roller 13. Then, it is carried into the fixing unit 20. The toner image is heat-fixed on the recording medium S by the fixing unit 20. Thereafter, the recording medium S is discharged from the discharge unit 24 to the outside of the apparatus main body A by the discharge roller pair 23.

(Process cartridge)
Next, the cartridge 7 (7a-7d) according to the present embodiment will be described with reference to FIG. FIG. 2 is a sectional view of the cartridge according to the present embodiment.

  The cartridge 7a containing yellow toner, the cartridge 7b containing magenta toner, the cartridge 7c containing cyan toner, and the cartridge 7d containing black toner have the same configuration. Therefore, in the following, the cartridge 7 (7a) containing yellow toner will be described, and the others will be omitted.

  The cartridge 7 includes a photosensitive unit 50 including a photosensitive drum 1, a charging roller 2, and a cleaning blade 6, and a developing unit 4 having a developing unit that are rotatably coupled and integrated.

  The photosensitive unit 50 rotatably supports the photosensitive drum 1 on a cleaning frame 51 that is a first frame via bearings 31L and 31R. Around the photosensitive drum 1, the above-described charging roller 2 and blade 6 are disposed. Further, the residual toner removed from the surface of the photosensitive drum 1 by the blade 6 is sent to the removed toner chamber 53 by the toner feeding mechanism 52. The toner chamber 53 is provided behind the cleaning frame 51. Then, the driving force of a driving motor (not shown) is transmitted to the photoreceptor unit 50. As a result, the photosensitive drum 1 rotates according to the image forming operation. The drive motor (not shown) is provided in the apparatus main body A.

  The developing unit 4 includes a developing roller 40 that rotates in contact with the photosensitive drum 1 (in the direction of arrow r2), the toner container 41, and a developing frame 45 that is a second frame. The developing roller 40 is rotatably supported by the developing frame body 45 through bearing members 47 and 48. Further, a toner supply roller 43 and a developing blade 44 are disposed on the peripheral surface of the developing roller 40, respectively. Further, in the toner container 41, a transport mechanism 42 for stirring the stored toner and transporting it to the toner supply roller 43 is provided.

  The developing unit 4 is coupled to the photoconductor unit 50 so as to be rotatable with respect to the photoconductor unit 50. That is, the developing unit 4 is coupled to the photoconductor unit 50 so as to be rotatable with respect to the photoconductor unit 50 around a shaft 41e that is a rotation center provided in the developing frame 45.

  In a state where the cartridge 7 is not attached to the apparatus main body A, the developing roller 40 contacts the photosensitive drum 1 by the rotational moment about the shaft 41e. That is, the developing roller 40 is urged toward the photosensitive drum 1 by a pressure spring (compression coil spring) 54 that is a pressing member.

(Separation mechanism between photosensitive drum and developing member)
Next, a mechanism for separating the photosensitive drum and the developing member when the cartridge 7 is mounted on the apparatus main body A will be described with reference to FIGS. FIG. 3 is a perspective view for explaining a state where the cartridge 7 is attached to the apparatus main body A. FIG. 4 and 5 are perspective views for explaining a separation structure according to the present embodiment. In FIG. 3, the cartridge 7 is omitted and only the photosensitive drum 1 and the bearings 31a and 31b are shown. This is for easy understanding of the mounting configuration of the cartridge 7.

When the cartridge 7 is not attached to the apparatus main body A, the developing roller 40 is always in contact with the photosensitive drum 1 (see FIG. 2). The cartridge 7 is mounted on the apparatus main body A by inserting the bearings 31a and 31b that support the photosensitive drum 1 along the guide grooves 34a to 34h (see FIG. 3, the arrow X direction indicates the mounting of the cartridge 7). direction). The cartridge 7 mounted on the apparatus main body A is separated from the photosensitive drum 1 and the developing roller 40 by separation members 8R (8Ra to 8Rd) and 8L (8La to 8Ld) which are cam members described later.

(Separation member)
Here, the mounting portion 100a located at the lowest position will be described as an example. In addition, naturally the structure of the other mounting parts 100b-100d is also the same.

  As shown in FIGS. 4 and 5, the separation member 8Ra is attached to a through shaft 8c1 that is a support shaft. The separating member 8Ra rotates about the through shaft 8c1 as a rotation axis. A part of each of the separation members 8Ra and 8La protrudes from an opening 32f provided in the frame body 32c of the apparatus main body A. Therefore, the distance between the cartridge 7 and the frame 32c can be reduced. As a result, the size of the image forming apparatus in the mounting direction of the cartridge can be reduced.

  The main body frame 32c has a laser opening 32h through which laser light passes. Here, the openings 32f and 32g are disposed outside the laser opening 32h in the longitudinal direction. That is, according to the configuration, the strength of the main body frame 32c can be increased. Therefore, the strength of the apparatus main body A is increased.

  On the other hand, the developing device frame 45 has a first recess 45 a so that the separating member 8 Ra overlaps the cartridge 7 in the longitudinal direction of the photosensitive drum 1. In addition, a force receiving portion 46e that is a cam engaging portion that contacts the separating member 8Ra and serves as a power point of the separating operation is provided to protrude in the longitudinal direction of the developing device frame 45. And the force receiving part 46e is provided in the downstream in the mounting direction of the cartridge 7 rather than the 1st recessed part 45a. With this configuration, the amount that the separating member 8Ra can enter the first recess 45a is increased, and the apparatus main body A can be downsized.

  In this embodiment, the separating member 8Ra is a cam. Initially, the position is not in contact with the force receiving portion 46e (second position). Then, by rotating around the through shaft 8c1, the force receiving portion 46e is lifted in the arrow B direction (first position). The developing unit 4 rotates about a shaft 41e that is the rotation center. As shown in FIG. 6, the developing roller 40 is positioned upstream of the shaft 41e in the mounting direction, and the force receiving portions 46e and 46f are positioned downstream of the mounting direction. As a result, the developing roller 40 is reliably separated from the photosensitive drum 1. Here, the separating member 8Ra has a cam shape, but may have a lever shape.

  As described above, by providing the first recess 45a, the cartridge 7 and the separation member 8Ra can be arranged to overlap in the longitudinal direction. That is, at least a part of the separating member 8Ra enters the first recess 45a provided on one end side in the longitudinal direction of the developing device frame 45 in the longitudinal direction. Therefore, the size of the image forming apparatus A in the longitudinal direction and the height of the image forming apparatus can be reduced. Therefore, the image forming apparatus A can be reduced in size.

As shown in FIG. 8, the image forming apparatus A according to this embodiment includes a plurality of cartridges 7 arranged in the vertical direction (the height direction of the image forming apparatus A) (only the cartridge 7 and the separation member 8 are described). ). That is, the mounting portions 7a to 7d are arranged side by side in the vertical direction. Therefore, the cleaning frame 51 has a third recess 51a that is a third intrusion portion at a position where the separating member 8Rb, which is another upper cam member, overlaps the cartridge 7 in the longitudinal direction. That is, at least a part of the separating member 8Rb enters the third recess 51a provided on one end side in the longitudinal direction of the cleaning frame 51 (longitudinal direction of the photosensitive drum 1) in the longitudinal direction. The third recess 51 a is provided on the upper portion of the cartridge 7. Thereby, when the separating member 8Rb provided between the adjacent cartridges 7 (for example, between the cartridges 7a and 7b) rotates, the first recess 45a of one cartridge and the third recess of the adjacent cartridge It can be arranged to allow the separating member 8Rb to enter 51a. Therefore, in the case of a color image forming apparatus in which a plurality of cartridges are arranged in the vertical direction, the size in the vertical direction can be reduced among the sizes of the image forming apparatuses.

  Further, in the separation mechanism according to the present embodiment, the separation member 8Ra is attached to the through shaft 8c. The separation member 8Ra is connected to a separation member 8La, which is a second cam member, provided on the other end side in the longitudinal direction via the through shaft 8c (see FIG. 5). Further, a part of the separating member 8La protrudes from an opening 32g provided in the frame body 32c. Therefore, the distance between the cartridge 7 and the frame 32c can be reduced. Thereby, the mounting direction of the cartridge can be reduced in the size of the image forming apparatus. The opening 32g is disposed on the outer side in the longitudinal direction than the laser opening 32h.

  On the other hand, the developing device frame 45 has a second recess 45b as a second entry portion so that the separation member 8La overlaps the cartridge 7 at the other end in the longitudinal direction, like the first recess 45a. That is, at least a part of the separation member 8La enters the second recess 45b provided on the other end side in the longitudinal direction of the developing device frame 45 in the longitudinal direction. Therefore, the image forming apparatus A can be reduced in size. In addition, a force receiving portion 46 f that is a second cam engaging portion that abuts the separating member 8 La and serves as a power point of the separating operation is provided so as to protrude in the longitudinal direction of the developing device frame 45.

  In this embodiment, the separating member 8La is a cam. Initially, the position is not in contact with the force receiving portion 46f (second position). And it rotates with the separating member 8Ra around the through shaft 8c1. Thereby, not only the force receiving portion 46e but also the force receiving portion 46f is lifted in the direction of the arrow B (first position). The developing unit 4 rotates about the shaft 41e. The positional relationship between the force receiving portion 46f and the second recess 45b and the positional relationship between the force receiving portion 46f, the shaft 41e, and the developing roller 40 are the same as those at one end in the longitudinal direction.

  In this manner, by lifting the force receiving portions 46e and 46f provided on both sides of the cartridge 7, the operation of separating the photosensitive drum 1 and the developing roller 40 can be performed more reliably and accurately. Further, as shown in FIG. 9, in the longitudinal direction of the photosensitive drum 1, a side 45d on the other end side of the developing frame 45 is provided in the apparatus main body A for applying a developing bias to the developing roller 40. Development bias contact portions (45e, 45f) that come into contact with the main body development bias contact (not shown). The developing bias contact portions (45e, 45f) are provided outside the second recess 45b in the longitudinal direction. With this configuration, the size of the apparatus main body A in the longitudinal direction can be reduced, and the apparatus main body A can be reduced in size.

  As shown in FIG. 9, the image forming apparatus A according to the present embodiment includes a plurality of cartridges 7 arranged in the vertical direction (only the cartridge and the separation member 8 are described). Therefore, the cleaning frame 51 has a fourth recess 51b that is a fourth intrusion portion at a position where the separating member 8Lb, which is the second other cam member above, overlaps the cartridge 7 in the longitudinal direction. That is, at least a part of the separating member 8Lb enters the fourth recess 51b provided on the other end side in the longitudinal direction of the cleaning frame 51 in the longitudinal direction. This allows the spacing member 8Lb to enter the first recess 45b of one cartridge and the fourth recess 51b of the adjacent cartridge when the spacing member 8Lb provided between the adjacent cartridges rotates. Can be arranged as follows. Therefore, in the color image forming apparatus in which a plurality of cartridges are arranged in the vertical direction, the vertical direction of the size of the image forming apparatus can be reduced even if a plurality of force receiving portions that are lifted by a plurality of separating members are provided.

  Next, the arrangement state of the separation member with respect to the cartridge 7 will be described with reference to FIGS. FIG. 6 is a side view of the process cartridge according to this embodiment. FIG. 7 is a schematic diagram showing the positional relationship in the longitudinal direction between the process cartridge and the separation member according to the present embodiment.

  As shown in FIGS. 6 and 7, the separating members 8Ra and 8La rotate around the through shaft 8c1. As a result, the force receiving portion 46f (46e) receives a force in the arrow B direction. The developing unit 4 rotates around the shaft 41e. Therefore, the developing roller 40 is separated from the photosensitive drum 1. The separation members 8Ra and 8La are disposed so as to protrude from the opening 32g provided in the frame body 32c. Therefore, the gap 61 between the tip (L2) of the developing frame 45 and the frame 32c in the cartridge mounting direction can be reduced.

  The rotation center of the penetrating shaft 8c1 is provided below the cartridge 7 in the state where the cartridge 7 is mounted on the apparatus main body A with respect to the line L1 connecting the shaft 41e and the distal ends of the force receiving portions 46f and 46e. With this configuration, the force receiving portions 46f and 46e can efficiently receive the force in the B direction from the separating members 8Ra and 8La.

  The center of rotation of the through shaft 8c1 is provided upstream of the line L2 at the front end in the mounting direction of the developing device frame 45 and below the rear end portion 45c of the arc shape below the front end in the mounting direction of the developing device frame 45. It has been. By providing the rotation center of the through shaft 8c1 at the above position, the distance in the vertical direction between adjacent cartridges can be reduced. Therefore, the size of the apparatus main body A can be reduced.

  Also, the gap 61 can be reduced in the mounting direction. Therefore, the size of the apparatus main body A can be reduced. The curvature (R) outside the rear end 45c is determined based on the rotation radius of the transport mechanism 42. In the present embodiment, the curvature on the outside of the rear end portion 45 c is R <b> 1 from the rotation center 42 a of the transport mechanism 42. The rotation center of the through shaft 8c1 is at a distance R2 from the rotation center 42a of the transport mechanism 42. Therefore, the center of rotation of the through shaft 8c1 only needs to be at a position of r2> r1 + d1 / 2.

  In the present embodiment, the shape of the rear end portion 45c is indicated by a curvature, but may be a slope shape as long as the penetration of the through shaft 8c1 can be permitted. The distance l1 between the center of the shaft 41e and the points 46f1 and 46e1 at which the force receiving portions 46f and 46e receive force from the separating members 8Ra and 8La is greater than the distance l2 between the center of the shaft 41e and the rotation center of the developing roller 40. large. Therefore, the force for pushing up the second frame 45 in the B direction by the separating members 8Ra and 8La is small. Therefore, a small motor (not shown) that transmits the driving force of the separating members 8Ra and 8La provided in the apparatus main body A can be used, and the apparatus main body A can be downsized.

  Therefore, it is not necessary to provide a space for disposing the separation member between the cartridge 7 and the frame 32c of the image forming apparatus main body A. Therefore, the image forming apparatus main body A can be reduced in size.

  Even when the size of the toner container is increased in order to extend the life of the cartridge, the first recess 45a and the second recess 45b provided in the developing frame 45 may be enlarged. By doing so, even if larger separating members 8Ra and 8La for lifting the force receiving portions 46e and 46f are necessary, it is possible to prevent the image forming apparatus main body from being enlarged.

Further, force receiving portions 46e and 46f are provided at the end portions in the longitudinal direction of the developing device frame 45 (longitudinal direction of the photosensitive drum 1). Accordingly, for example, compared with a case where a force receiving portion is provided in the central portion in the longitudinal direction of the toner container 41 shown in FIG. 2, the conveyance mechanism is not deformed due to interference with the conveyance mechanism. Further, it is possible to prevent the toner agitation in the portion corresponding to the concave portion from becoming unstable. Therefore, image defects or the like do not occur in the portion where the concave portion exists in the longitudinal direction.

  Also, compared with the case where the concave portion is provided at the center, openings 32f and 32g are separately provided outside the laser opening 32h. As a result, the strength of the frame does not decrease.

  In addition, force receiving portions 46e and 46f are provided at the ends in the longitudinal direction of the frame (longitudinal direction of the photosensitive drum 1). Therefore, the deformation of the cartridge 7 is small when the force receiving portions 46e and 46f receive force from the separating members 8Ra and 8La. As for this, the side wall is arrange | positioned in the edge part of the longitudinal direction of the image development frame 45 or the cleaning frame 51. FIG. Further, many gears and support members are arranged. This is because the strength is high. In addition, it is not easily affected by warpage of molded products. Therefore, the dimension of the force receiving portion is stabilized. That is, variation in the dimensions of the force receiving portions 46e and 46f can be suppressed. Therefore, it is possible to reduce the margin of the separation amount necessary for reliably separating the developing roller 40 from the photosensitive drum 1. Thereby, the responsiveness accuracy of the separation operation can be improved.

  As shown in FIG. 10, the developing frame 45 is composed of three frames, a blade support frame 45g, a first side plate 45h, and a second side plate 45j. The blade support frame 45g supports the developing blade 44. The first side plate 45h and the second side plate 45j rotatably support the developing roller 40 and the toner transport roller 43. The side plates 45h and 45j support a gear (not shown) for transmitting a driving force to the rollers 40 and 43. The force receiving portion 46e is provided on the first side plate 45h, and the force receiving portion 46f is provided on the second side plate 45j. Further, the first side plate 45h is provided with a support portion 45h1 into which a shaft (not shown) rotatably supported by the first side plate 45h and the cleaning frame body 51 is inserted. Similarly, the second side plate 45j is provided with a support portion 45j1 into which a shaft (not shown) rotatably supported by the second side plate 45j and the cleaning frame body 51 is inserted.

  Therefore, the positional relationship between the developing roller 40, the developing unit shaft 41e, and the force receiving portions 46e and 46f in the cartridge 7 can be accurately guaranteed. These tolerances are therefore reduced. Therefore, it is possible to reduce the margin of the separation amount necessary for reliably separating the developing roller 40 from the photosensitive drum 1. Therefore, the responsiveness of the separating operation can be improved. Further, the operation of the image forming apparatus main body A can be speeded up.

  In this embodiment, the intrusion portion (first recess) 45a is the outermost part of the second frame 45 (at least one of the developing frame and the developer container) when the cartridge 7 is mounted with the apparatus main body A. A first horizontal plane passing through the lower point, a second horizontal plane passing through the uppermost point of the second frame 45, a first vertical plane passing through the most downstream side of the second frame 45 in the mounting direction of the cartridge 7, and in the longitudinal direction In the space surrounded by the second vertical surface passing through the outermost side of the second frame 45, it is a region that allows at least a part of the cam member 8Ra to enter.

  Similarly, the second intrusion portion (second concave portion) 45b is the second frame 45 (at least one of the developing frame and the developer container) when the cartridge 7 is mounted with the apparatus main body A. A first horizontal plane passing through the lower point, a second horizontal plane passing through the uppermost point of the second frame 45, a first vertical plane passing through the most downstream side of the second frame 45 in the mounting direction of the cartridge 7, and in the longitudinal direction In the space surrounded by the second vertical surface passing through the outermost side of the second frame 45, it is a region that allows at least a part of the cam member 8La to enter.

The third intrusion portion (third recess) 51a includes a first horizontal plane that passes through the lowest point of the cartridge 7 and a second horizontal plane that passes through the highest point of the cartridge 7 when the cartridge 7 is mounted with the apparatus main body A. In the space surrounded by the first vertical surface passing through the most downstream side of the cartridge 7 in the mounting direction of the cartridge 7 and the second vertical surface passing through the outermost side of the cartridge 7 in the longitudinal direction, at least a part of the cam member 8Rb It is an area that allows intrusion.

  Similarly, the fourth intrusion portion (fourth concave portion) 51b also has a first horizontal plane that passes through the lowest point of the cartridge 7 and a second passage that passes through the uppermost point of the cartridge 7 when the cartridge 7 is mounted with the apparatus main body A. In a space surrounded by a horizontal plane, a first vertical surface passing through the most downstream side of the cartridge 7 in the mounting direction of the cartridge 7 and a second vertical surface passing through the outermost side of the cartridge 7 in the longitudinal direction, at least the cam member 8Lb It is an area that allows some intrusion.

  Further, the process cartridge 7 described in the present embodiment can also be described as follows. This will be described with reference to FIG.

That is, the cartridge 7 is attachable to the main body A of the image forming apparatus, and is an upper concave portion X1 that is recessed inward in the longitudinal direction at the longitudinal end portion of the photosensitive drum 1, and the cartridge 7 is attached to the main body A. An upper part in the vertical direction at the time of attachment and an upper recessed part X1 in which the end on the front end side is open in the direction in which the cartridge 7 is attached to the main body A, and a lower recessed part Y1 indented in the longitudinal direction at the end in the longitudinal direction A vertical lower portion when the cartridge 7 is attached to the main body A and a lower concave portion Y1 whose front end is open in a direction of attaching the cartridge 7 to the main body A, The upper recess when the upper recess X1 and the lower recess move the upper recess X1 in a predetermined direction (Z1 direction) by a predetermined distance (virtually). And X1 ', between the lower recess Y1 (virtual) Synthesis recess (Y
+ X ′) is formed, and the synthetic recess (Y + X ′) has a shape that allows the member (8Rd, 8Ld) that is provided in the main body A to act on the process cartridge to enter. It is a cartridge.

  The members (8Rd, 8Ld) acting on the cartridge 7 are cam members (8Rd, 8Ld). Further, the predetermined distance is a distance larger than the maximum dimension of the cartridge 7 in the vertical direction.

  That is, as described above, when the cartridge 7 of this embodiment is attached to the main body A, the adjacent process cartridges jointly form a space allowing the cams (8Rd, 8Ld) to enter. Is described as a configuration of one process cartridge as follows.

  As shown in FIG. 11, the cartridge 7 has an upper recess X1 at the end in the longitudinal direction, and the upper recess X1 is recessed inward in the longitudinal direction. The upper concave portion X1 is open at the top in the vertical direction when the cartridge 7 is attached to the main body A, and the end on the front end side is open at the direction in which the cartridge 7 is attached to the main body A. ing.

  Further, the cartridge 7 has a lower recess Y1 at an end in the longitudinal direction, and the lower recess Y1 is recessed inward in the longitudinal direction. The lower concave portion Y1 is open at the lower portion in the vertical direction when the cartridge 7 is attached to the main body A, and the front end side end portion is open at the direction in which the cartridge 7 is attached to the main body A. ing. The upper recess X1 and the lower recess Y1 are separately provided at separate positions, but are organically related as follows.

That is, the upper concave portion X1 and the lower concave portion Y1 virtually divide the upper concave portion X1 by a predetermined distance in a predetermined direction (a direction in which a plurality of cartridges are stacked, that is, a direction inclined about 10 ° in the vertical direction in this embodiment). Virtual upper recess X1 ′ shape (2) when moved (in the direction of arrow Z1)
A partially hypothetical recess (Y1 + X1 ′) is synthesized and formed with the actual shape of the lower recess Y1). The virtual composite recess (Y1 + X1 ′) has an open end on the front end side in the direction in which the cartridge 7 is attached to the image forming apparatus main body A, and the virtual composite recess (Y1 + X1 ′) passes through the open portion. The cams (8Rd, 8Ld) have dimensions and shapes that allow the cams (8Rd, 8Ld) to enter and further allow their rotation.

  In this embodiment, the predetermined distance is a pitch between adjacent process cartridges when the plurality of cartridges 7 (7a, 7b, 7c, 7d) are provided in the image forming apparatus main body A (the above-mentioned distance). Equal to the distance measured in a given direction).

  When a plurality of cartridges 7 (7a, 7b, 7c, 7d) are attached to the image forming apparatus main body A, the adjacent cartridges 7 (7a, 7b, 7c, 7d) do not have a portion that fits into each other. The predetermined distance is larger than the maximum height (the dimension measured in the vertical direction) of the process cartridge.

  Since one process cartridge has the upper concave portion X1 and the lower concave portion Y1 having such a shape and positional relationship, when a plurality of cartridges 7 (7a, 7b, 7c, 7d) are mounted side by side in a predetermined direction, the cam (8Rd , 8Ld), the distance between adjacent cartridges 7 can be reduced without interfering with the action.

  In the present embodiment, such recesses X1 and Y1 are provided at both ends in the longitudinal direction. However, they may be provided only on one side as long as the cam operation is not hindered.

  In this embodiment, the members allowed to enter the recesses are the cam members (8Rd, 8Ld). However, the present invention is not limited to this, and for example, moves in the vertical direction. Even in the case of a member such as a lever, the effect of the present invention is exhibited.

  In the description of the present embodiment, the cartridge 7 mounted on the lowermost side of the apparatus main body A out of the four process cartridges 7 has been mainly described. However, the other cartridges 7 have the same configuration.

Next, a modification of the embodiment will be shown.
(Overall configuration of electrophotographic image forming apparatus)
First, an outline of an electrophotographic image forming apparatus according to a modification will be described with reference to FIG. FIG. 12 is a perspective view of a color electrophotographic image forming apparatus according to a modification. FIG. 13 is a perspective view seen from the direction of arrow V1 in FIG.

  The electrophotographic image forming apparatus (hereinafter referred to as “image forming apparatus”) B has four sets of cartridge mounting means (not shown) arranged side by side in the horizontal direction, and each of the cartridges 70 (70a to 70d) is an arrow direction M1. It is removable. The configuration of the cartridge 70 is the same as that of the cartridge 7 of the embodiment.

  On the other hand, the image forming apparatus main body B has a transfer belt 111 that circulates and contacts all the photosensitive drums 1a to 1d. The transfer belt 111 is a film-like member as in the embodiment. The recording medium S is conveyed to the transfer position by the transfer belt 111. Then, the toner image formed on the photosensitive drum 1 at the transfer position is transferred to the recording medium S.

  The transfer roller 112 (112a to 112d) is in contact with the inside of the transfer belt 111. The transfer roller 112 is provided side by side at a position facing the four photosensitive drums 1 (1a to 1d) with the transfer belt 111 interposed therebetween. Then, a positive charge is applied to the recording medium S via the transfer belt 111 by the transfer roller 112. As a result, the toner image formed on the photosensitive drum 1 is transferred to the recording medium S. The transfer belt 111 is stretched by four rollers, ie, a driving roller 113, driven rollers 114a and 114b, and a tension roller 115, and rotates (in the direction of arrow r1). Thereby, the transfer belt 111 circulates and moves. The toner image is transferred while the recording medium S is conveyed from the driven roller 114a side to the driving roller 113 side.

  The feeding unit 116 feeds and conveys the recording medium S to the image forming unit. A plurality of recording media S are stored in the feeding cassette 117. At the time of image formation, the feeding roller 118 and a registration roller pair (not shown) rotate according to the image forming operation. Thereby, the recording medium S in the cassette 117 is separated and fed one by one. The leading edge of the recording medium S hits a pair of registration rollers (not shown) and stops temporarily. The recording medium S is fed to the transfer belt 111 by a pair of registration rollers (not shown) in synchronization with the rotation of the transfer belt 111 and the toner image.

  The fixing unit 120 fixes the toner images of a plurality of colors transferred to the recording medium S. The image forming operation is the same as in the embodiment. As described above, the recording medium S sequentially applies the toner images on the photosensitive drums 1 by the electric field formed between the photosensitive drums 1 and the transfer rollers 112. Transcribed. The recording medium S on which the four color toner images are transferred is separated from the transfer belt 111 by the curvature of the driving roller 113. Then, it is carried into the fixing unit 120. The toner image is heat-fixed on the recording medium S by the fixing unit 120. Thereafter, the recording medium S is discharged out of the apparatus main body B from the discharge unit 124 by a discharge roller pair (not shown).

(Separation mechanism between photosensitive drum and developing member)
When the cartridge 70 is not attached to the apparatus main body B, the developing roller 140 is always in contact with the photosensitive drum 100 (see FIG. 14). The cartridge 70 is attached to the apparatus main body B by being inserted along a guide groove (not shown) of the apparatus main body B (see FIG. 12). In the cartridge 70 mounted on the apparatus main body B, the separation operation of the photosensitive drum 1 and the developing roller 140 is performed by the separation member 80a which is a cam member, as in the embodiment. That is, the developing frame 145 rotates in the arrow direction M2 around the coupling portion 141e with the cleaning frame 151 to perform the separating operation of the developing roller 140.

  On the other hand, the developing device frame 145 has a first recess 145a so that the separating member 80a overlaps the cartridge 70 in the longitudinal direction (mounting direction) of the photosensitive drum 1. Further, a force receiving portion 146a that is a cam engaging portion that contacts the separation member 80a and serves as a power point of the separation operation is provided in the developing device frame 145. As shown in FIG. 13, the force receiving portion 146 a is also provided in the first recess 145 a so as to overlap the cartridge 70 in the longitudinal direction (mounting direction) of the photosensitive drum 1. According to the configuration, the amount that the separating member 80a can enter the first recess 145a in the longitudinal direction is increased. Therefore, the size of the image forming apparatus B in the longitudinal direction (mounting direction) and the size of the image forming apparatus B in the horizontal direction (width) can be reduced. Therefore, the image forming apparatus B can be downsized.

As shown in FIG. 13, the image forming apparatus B according to the modified example includes a plurality of cartridges 70 arranged in the horizontal direction (the width direction of the image forming apparatus B) (only the cartridge 70 and the separation member 80a are described). Therefore, the cleaning frame 151 has a second recess 151a that is a second intrusion portion at a position where the separating member 80b that is another adjacent cam member overlaps the cartridge 70 in the longitudinal direction. That is, at least a part of the separating member 80b enters the second recess 151a provided on one end side in the longitudinal direction of the cleaning frame 151 (longitudinal direction of the photosensitive drum 1) in the longitudinal direction. The second recess 151a is provided at the end opposite to the first recess 145a in the horizontal direction.

  Accordingly, when the separation member 80b provided between the adjacent cartridges 70 (for example, between the cartridges 70a and 70b) rotates, the first recess 145a of one cartridge and the second recess of the adjacent cartridge It can be arranged to allow the spacing member 80b to enter 151a. Therefore, in the case of a color image forming apparatus in which a plurality of cartridges are arranged side by side in the horizontal direction, the size in the horizontal direction can be reduced among the sizes of the image forming apparatuses.

  Further, the process cartridge 70 described in the modified example can be described as follows. This will be described with reference to FIG.

  In other words, the cartridge 70 can be attached to the main body B of the image forming apparatus in the longitudinal direction of the cartridge 70, and the first concave portion X <b> 1 (151 d) that is recessed inward in the longitudinal direction at the longitudinal end portion of the photosensitive drum 100. A first recess X1 in which a horizontal end when the cartridge 70 is attached to the main body B and an upper portion when the cartridge 70 is attached to the main body B are open; and an end in the longitudinal direction The second concave portion Y1 (145d) is recessed inward in the longitudinal direction, and the other end portion in the horizontal direction when the cartridge 7 is attached to the main body B and the cartridge 70 when the cartridge 70 is attached to the main body B. A second recess Y1 whose upper portion is open, and the first recess X1 and the second recess Y1 pass the first recess X1 in a predetermined direction (Z1 direction). ) When the first recess X1 ′ and the second recess Y1 are moved to a predetermined distance (virtually) to form a (virtual) composite recess (Y + X1 ′), and the composite recess (Y + X1 ′) The process cartridge is characterized in that it has a shape that allows the member 80d that is provided in the main body B to act on the process cartridge 70 to enter.

  The member 80d acting on the cartridge 70 is a cam member 80d. Further, the predetermined distance is a distance larger than the maximum horizontal dimension of the cartridge 70.

  That is, as described above, when the cartridge 70 according to the modified example is attached to the apparatus main body B, the adjacent process cartridges jointly form a space allowing the cam 80d to enter. The configuration of the cartridge will be described as follows.

  As shown in FIG. 15, the cartridge 70 has a first recess X1 (151d) at the end in the longitudinal direction, and the first recess X1 is recessed inward in the longitudinal direction. The first recess X1 is open at one end in the horizontal direction when the cartridge 70 is attached to the main body B, and has an upper portion when the cartridge 7 is attached to the main body B. It is open.

  Further, the cartridge 7 has a second recess Y1 (145d) at the end in the longitudinal direction, and the second recess Y1 is recessed inward in the longitudinal direction. The other end of the second recess Y1 is open in the horizontal direction when the cartridge 70 is attached to the main body B, and the upper portion when the cartridge 70 is attached to the main body B is open. ing. The first recess X1 and the second recess Y1 are separately provided at separate positions, but are organically related as follows.

  That is, the first concave portion X1 (151d) and the second concave portion Y1 (145d) are virtual for the first concave portion X1 by a predetermined distance in a predetermined direction (a direction in which a plurality of cartridges are stacked, that is, a horizontal direction in a modified example). Is partially formed by the virtual upper concave portion X1 ′ shape (indicated by a two-dot chain line) when it is moved to (arrow Z1 direction) and the actual second concave portion Y1 shape. . The virtual synthetic recess (Y1 + X1 ′) is opened upward in the direction in which the cartridge 70 is attached to the image forming apparatus main body B, and the virtual synthetic recess (Y1 + X1 ′) passes through the open portion and the cam. (80d) has a size and shape that allows intrusion and also allows rotation thereof.

  In this modification, the predetermined distance is the pitch between the adjacent process cartridges when the plurality of cartridges 70 (70a, 70b, 70c, 70d) are provided in the image forming apparatus main body B (the above-mentioned distance). Equal to the distance measured in a given direction).

  When a plurality of cartridges 70 (70a, 70b, 70c, 70d) are attached to the image forming apparatus main body B, the adjacent cartridges 70 (70a, 70b, 70c, 70d) do not have a portion in a fitting relationship with each other. The predetermined distance is larger than the maximum height (the dimension measured in the vertical direction) of the process cartridge.

  Since one process cartridge has the first recess X1 and the second recess Y1 having such a shape and positional relationship, when a plurality of cartridges 70 (70a, 70b, 70c, 70d) are mounted side by side in a predetermined direction, the cam The distance between the adjacent cartridges 70 can be reduced without hindering the action (80d).

1 is a cross-sectional view of a color electrophotographic image forming apparatus according to an embodiment. It is sectional drawing of the process cartridge which concerns on an Example. FIG. 3 is a perspective view for explaining a state in which a process cartridge is mounted on the electrophotographic image forming apparatus main body. It is a perspective view for demonstrating the separation structure which concerns on an Example. It is a perspective view for demonstrating the separation structure which concerns on an Example. It is a side view showing a process cartridge according to an example. It is the schematic diagram which showed the positional relationship of the longitudinal direction of the process cartridge and spacing member which concerns on an Example. It is a perspective view explaining the separation structure concerning an example. It is a perspective view explaining the separation structure concerning an example. It is a perspective view explaining the detail of the 2nd frame which concerns on an Example. 1 is an external perspective view of a process cartridge according to an embodiment. It is a perspective view of a color electrophotographic image forming apparatus according to a modification. FIG. 13 is a perspective view of the process cartridge as seen from the direction of arrow V1 shown in FIG. 12. It is sectional drawing of the process cartridge which concerns on a modification. It is a perspective view for demonstrating the separation structure which concerns on a modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electrophotographic photosensitive drum 2 Charging roller 3 Scanner unit 4 Developing unit 5 Transfer means 6 Cleaning blade 7 Process cartridge 8 (8Ra, 8Rb, 8La, 8Lb) Cam member (separating member)
8c Through shaft 31a Bearing 32c Main body frame 32f, 32g Opening 32h Laser opening 40 Developing roller 41 Toner container 41e Shaft 42a Rotation center 44 Developing blade 45 Developing frame (second frame)
45a First concave portion 45b Second concave portion 46e, 46f Force receiving portion 46f1, 46e1 Point receiving force 47 Bearing member 50 Photosensitive unit 51 Cleaning frame 51a Third concave portion 51b Fourth concave portion 70 Process cartridge 80 Separating member 100 Mounting portion 145 Development frame 151 Cleaning frame A, B Image forming apparatus main body

Claims (3)

A process cartridge attachable to the electrophotographic image forming apparatus main body,
An electrophotographic photosensitive drum;
A developing roller for developing the electrostatic latent image formed on the electrophotographic photosensitive drum in contact with the electrophotographic photosensitive drum;
A cartridge frame,
A first recess recessed inwardly in the longitudinal direction of the cartridge frame at the end in the longitudinal direction of the electrophotographic photosensitive drum, and one end in the horizontal direction when the process cartridge is attached to the apparatus main body And a first recess having an open upper portion when the process cartridge is attached to the apparatus main body,
A second recess recessed inwardly in the longitudinal direction of the cartridge frame at the end in the longitudinal direction, the other end in the horizontal direction when the process cartridge is attached to the apparatus main body and the process cartridge; A second recess having an open upper part when attached to the apparatus body,
A synthetic recess formed by a virtual first recess when the first recess is moved by a predetermined distance in a predetermined direction and a second recess is a member that acts on the process cartridge provided in the apparatus main body. A process cartridge having a shape that allows intrusion.   The process cartridge according to claim 1, wherein the member acting on the process cartridge is a cam member.   The process cartridge according to claim 1, wherein the predetermined distance is larger than a maximum dimension of the process cartridge in the horizontal direction.

Images