HK1150404B - Process cartridge and image forming apparatus - Google Patents

Description

Process cartridge and image forming apparatus

The present application is a divisional application with application number 200780002318.1, applied on day 11/1 of 2007.

Technical Field

The present invention relates to a process cartridge in which an electrophotographic photosensitive drum and a developing roller are contactable with and separable from each other, and which is capable of acting on the electrophotographic photosensitive drum, and an electrophotographic image forming apparatus to which the process cartridge is detachably mountable.

Background

In an image forming apparatus utilizing an electrophotographic image forming process, a process cartridge type is conventional in which an electrophotographic photosensitive drum and a developing roller capable of acting on the electrophotographic photosensitive drum are integrated into a process cartridge, which is detachably mountable to a main assembly of the image forming apparatus. With this type of process cartridge, maintenance operations of the apparatus can be performed efficiently without the need for service personnel. Therefore, this type of process cartridge is widely used in the field of electrophotographic image forming apparatuses.

When an image forming operation is performed, the developing roller is always pushed toward the electrophotographic photosensitive drum with a predetermined pressure. In a contact development system in which a developing roller is brought into contact with a photosensitive drum during a developing operation, an elastic layer of the developing roller is brought into contact with the surface of the photosensitive drum at a predetermined pressure.

Therefore, when the process cartridge is not used for a long time and the process cartridge remains mounted to the main assembly of the image forming apparatus, the elastic layer of the developing roller may be deformed. If distortion occurs, non-uniformity may be generated in the formed image. Since the developing roller is in contact with the photosensitive drum, the developer can be deposited from the developing roller onto the photosensitive drum because the photosensitive drum and the developing roller rotate in contact with each other even when the developing operation is not performed.

As a structure for solving this problem, there is proposed an image forming apparatus in which a mechanism acts on a process cartridge to separate a developing roller from an electrophotographic photosensitive drum when an image forming operation is not performed (japanese patent application laid-open No. 2003-167499).

In the apparatus disclosed in this publication, four process cartridges are detachably mounted to the main assembly of the image forming apparatus. The process cartridge includes a photosensitive member unit having a photosensitive drum, and a developing unit for supporting a developing roller swingably provided in the photosensitive member unit. By moving a spacing plate provided in the main assembly of the image forming apparatus, a force receiving portion provided in the developing unit receives a force from the spacing plate. By moving the developing unit relative to the photosensitive member unit, the developing roller is moved away from the photosensitive drum.

In this conventional example, a force receiving portion for separating the developing roller from the photosensitive drum protrudes from an external structure of the developing unit. Therefore, the force receiving portion tends to be easily damaged when the user operates the process cartridge and/or when the process cartridge is transported. The presence of this force receiving portion may affect a reduction in size of the process cartridge (in which the electrophotographic photosensitive drum and the developing roller are contactable with and separable from each other) and the main assembly of the image forming apparatus (the main assembly to which the process cartridge is detachably mountable).

Disclosure of Invention

Accordingly, a primary object of the present invention is to provide a process cartridge which is reduced in size and in which an electrophotographic photosensitive drum and a developing roller are contactable with each other and separable from each other, and an electrophotographic image forming apparatus which is reduced in size and in which the process cartridge is detachably mountable.

Another object of the present invention is to provide a process cartridge in which an electrophotographic photosensitive drum and a developing roller are contactable with each other and separable from each other; with this process cartridge, the force receiving portion is not damaged when the process cartridge is operated or when the process cartridge is transported.

According to an aspect of the present invention, there is provided a process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, the main assembly including an opening, a door movable between a closed position for closing the opening and an open position for opening the opening, a first force application member movable in accordance with movement of the door from the open position to the closed position, and a second force application member movable by a driving force from a driving source, the process cartridge comprising: an electrophotographic photosensitive drum; a developing roller for developing an electrostatic latent image formed on the electrophotographic photosensitive drum; a drum unit including the electrophotographic photosensitive drum; a developing unit including the developing roller and movable relative to the drum unit so that the developing roller is movable between a contact position where the developing roller is in contact with the electrophotographic photosensitive drum and a spaced position where the developing roller is spaced from the electrophotographic photosensitive drum; and a force-receiving device comprising: a first force receiving portion for receiving a force from the first force application member by movement of the door from the open position to the closed position in a state in which the process cartridge is mounted to the main assembly of the apparatus through the opening; and a second force receiving portion movable from a standby position by the first force receiving portion moving upon receiving a force from the first force application member, wherein the second force receiving portion is in a protruding position for receiving a force from a second force application member to move the developing unit from the contact position to the spaced position, the protruding position being higher than the standby position.

According to another aspect of the present invention, there is provided an electrophotographic image forming apparatus for forming an image on a recording material, in which a process cartridge is detachably mountable, the apparatus comprising: (i) an opening; (ii) a door movable between a closed position closing the opening and an open position opening the opening; (iii) a first force application member movable with movement of the door from the open position to the closed position; (iv) a second urging member movable by a driving force from a driving source; (v) a mounting device for detachably mounting a process cartridge including an electrophotographic photosensitive drum; a developing roller for developing an electrostatic latent image formed on the electrophotographic photosensitive drum; a drum unit including the electrophotographic photosensitive drum; a developing unit including the developing roller and movable relative to the drum unit so that the developing roller is movable between a contact position where the developing roller is in contact with the electrophotographic photosensitive drum and a spaced position where the developing roller is spaced from the electrophotographic photosensitive drum; and a force-receiving device comprising: a first force receiving portion for receiving a force from the first force application member by movement of the door from the open position to the closed position in a state in which the process cartridge is mounted to the main assembly of the apparatus through the opening; and a second force receiving portion movable from a standby position by the first force receiving portion moving upon receiving a force from the first force application member, wherein the second force receiving portion is in a protruding position for receiving a force from a second force application member to move the developing unit from the contact position to the spaced position, the protruding position being higher than the standby position; and a feeding device for feeding the recording material.

These and other objects, features and advantages of the present invention will become more apparent after consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings.

Drawings

Fig. 1 shows the overall arrangement of an electrophotographic image forming apparatus according to a first embodiment of the present invention.

Fig. 2 is a sectional view of a process cartridge according to a first embodiment of the present invention.

Fig. 3 shows the overall arrangement of an electrophotographic image forming apparatus according to a first embodiment of the present invention.

Fig. 4 shows replacement of the process cartridge according to the first embodiment of the present invention.

Fig. 5 is a sectional view of the process cartridge when viewed along the axial direction of the photosensitive drum according to the first embodiment of the present invention.

Fig. 6 is a sectional view of the process cartridge when viewed along the axial direction of the photosensitive drum according to the first embodiment of the present invention.

Fig. 7 is a sectional view of the process cartridge when viewed along the axial direction of the photosensitive drum according to the first embodiment of the present invention.

Fig. 8 is a sectional view of the process cartridge when viewed along the axial direction of the photosensitive drum according to the first embodiment of the present invention.

Fig. 9 is a perspective view of the process cartridge when viewed from the driving side according to the first embodiment of the present invention.

Fig. 10 is a perspective view of the process cartridge when viewed from the driving side according to the first embodiment of the present invention.

Fig. 11 is a perspective view of the process cartridge when viewed from the non-driving side according to the first embodiment of the present invention.

Fig. 12 is a perspective view of the process cartridge when viewed from the non-driving side according to the first embodiment of the present invention.

Fig. 13 is a perspective view of the process cartridge when viewed from the non-driving side according to the first embodiment of the present invention.

Fig. 14 is a perspective view of the process cartridge when viewed from the non-driving side according to the first embodiment of the present invention.

Fig. 15 is a perspective view showing a force receiving device of the process cartridge according to the first embodiment of the present invention.

Fig. 16 is a perspective view showing a force receiving device of the process cartridge according to the first embodiment of the present invention.

Fig. 17 is a perspective view showing a force receiving device of the process cartridge according to the first embodiment of the present invention.

Fig. 18 is a perspective view showing a force receiving device of the process cartridge according to the first embodiment of the present invention.

Fig. 19 is a perspective view showing a force receiving device of the process cartridge according to the first embodiment of the present invention.

Fig. 20 is a perspective view showing a force receiving device of the process cartridge according to the first embodiment of the present invention.

Fig. 21 is a perspective view showing a force receiving device of the process cartridge according to the first embodiment of the present invention.

Fig. 22 shows a process cartridge according to the first embodiment of the present invention, in which the first force receiving member and the second force receiving member of the electrophotographic image forming apparatus act on the first force receiving member and the second force receiving member.

Fig. 23 is an overall arrangement of an electrophotographic image forming apparatus according to the first embodiment of the present invention.

Fig. 24 is an overall arrangement of an electrophotographic image forming apparatus according to the first embodiment of the present invention.

Fig. 25 is an overall arrangement of an electrophotographic image forming apparatus according to the first embodiment of the present invention.

Fig. 26 is an overall arrangement of an electrophotographic image forming apparatus according to the first embodiment of the present invention.

Fig. 27 shows the operation of the first force application member according to the first embodiment of the present invention.

Fig. 28 shows the operation of the second force application member according to the first embodiment of the present invention.

Fig. 29 is a perspective view of an electrophotographic image forming apparatus according to the first embodiment of the present invention.

Fig. 30 is a perspective view of an electrophotographic image forming apparatus according to the first embodiment of the present invention.

Fig. 31 shows replacement of the process cartridge according to the first embodiment of the present invention.

Fig. 32 shows replacement of the process cartridge according to the first embodiment of the present invention.

Fig. 33 is a sectional view of the process cartridge when viewed in the axial direction of the photosensitive drum, showing the operation of the force receiving member of the process cartridge, according to the first embodiment of the present invention.

Fig. 34 is a sectional view of the process cartridge when viewed in the axial direction of the photosensitive drum, showing the operation of the force receiving member of the process cartridge, according to the first embodiment of the present invention.

Fig. 35 is a sectional view of the process cartridge when viewed in the axial direction of the photosensitive drum, showing the operation of the force receiving member of the process cartridge, according to the first embodiment of the present invention.

Fig. 36 shows a dividing operation in the process cartridge according to the first embodiment of the present invention.

Fig. 37 shows a dividing operation in the process cartridge according to the first embodiment of the present invention.

Fig. 38 shows a dividing operation in the process cartridge according to the first embodiment of the present invention.

Fig. 39 is a general arrangement of an electrophotographic image forming apparatus according to a second embodiment of the present invention.

Fig. 40 is an overall arrangement of an electrophotographic image forming apparatus according to a second embodiment of the present invention.

Fig. 41 is an overall arrangement of an electrophotographic image forming apparatus according to a second embodiment of the present invention.

Fig. 42 illustrates an operation of the first force application operation member of the electrophotographic image forming apparatus according to the second embodiment of the present invention.

Fig. 43 is a diagram illustrating the operation of the first force application member according to the second embodiment of the present invention.

Fig. 44 is a diagram illustrating the operation of the first force application member according to the second embodiment of the present invention.

Fig. 45 is a diagram illustrating the operation of the first force application member according to the second embodiment of the present invention.

Fig. 46 is a sectional view of the process cartridge when viewed in the axial direction of the photosensitive drum according to the second embodiment of the present invention.

Fig. 47 shows a sectional view of the process cartridge when viewed in the axial direction of the photosensitive drum, showing the force receiving means of the process cartridge, according to the second embodiment of the present invention.

Fig. 48 shows a sectional view of the process cartridge when viewed in the axial direction of the photosensitive drum, showing the force receiving means of the process cartridge, according to the second embodiment of the present invention.

Fig. 49 shows a sectional view of the process cartridge when viewed in the axial direction of the photosensitive drum, showing the force receiving means of the process cartridge, according to the second embodiment of the present invention.

Fig. 50 shows a sectional view of the process cartridge when viewed in the axial direction of the photosensitive drum, showing the force receiving means of the process cartridge, according to the second embodiment of the present invention.

Fig. 51 is a sectional view of a process cartridge according to a third embodiment of the present invention, showing the operation of the force receiving member of the process cartridge.

Fig. 52 is a sectional view of a process cartridge according to a third embodiment of the present invention, showing the operation of the force receiving member of the process cartridge.

Fig. 53 is a sectional view of a process cartridge according to a third embodiment of the present invention, showing the operation of the force receiving member of the process cartridge.

Fig. 54 is a sectional view of a process cartridge according to a third embodiment of the present invention, showing the operation of the force receiving member of the process cartridge.

Fig. 55 is a sectional view of the process cartridge when viewed in the axial direction of the photosensitive drum, showing a force receiving device of the process cartridge, according to the fourth embodiment of the present invention.

Fig. 56 is a sectional view of the process cartridge when viewed in the axial direction of the photosensitive drum, showing a force receiving device of the process cartridge, according to the fourth embodiment of the present invention.

Fig. 57 is a sectional view of the process cartridge when viewed in the axial direction of the photosensitive drum, showing a force receiving device of the process cartridge, according to the fourth embodiment of the present invention.

Fig. 58 is a sectional view of the process cartridge when viewed in the axial direction of the photosensitive drum, showing a force receiving device of the process cartridge, according to the fourth embodiment of the present invention.

Fig. 59 is a perspective view of the process cartridge according to the fifth embodiment of the present invention when viewed from the driving side.

Fig. 60 is a perspective view of the process cartridge according to the fifth embodiment of the present invention when viewed from the driving side.

Fig. 61 is a sectional view of a process cartridge according to a sixth embodiment of the present invention.

Fig. 62 is a sectional view of a process cartridge according to a sixth embodiment of the present invention.

Fig. 63 is a sectional view of a process cartridge according to a sixth embodiment of the present invention.

Fig. 64 is a sectional view of a process cartridge according to a sixth embodiment of the invention.

Fig. 65 is a perspective view of a process cartridge according to the seventh embodiment, showing a force receiving device of the process cartridge.

Fig. 66 is a perspective view of a process cartridge according to the seventh embodiment, showing a force receiving device of the process cartridge.

Fig. 67 is a perspective view of a process cartridge according to the seventh embodiment, showing a force receiving device of the process cartridge.

Fig. 68 is a perspective view of a process cartridge according to the seventh embodiment, showing a force receiving device of the process cartridge.

Detailed Description

(first embodiment)

Referring to fig. 1 to 4, fig. 1 to 4 illustrate a process cartridge and an electrophotographic image forming apparatus according to a first embodiment of the present invention.

Fig. 1 shows an electrophotographic image forming apparatus (main assembly of the apparatus) 100 including detachably mountable process cartridges (cartridges) 50y, 50m, 50c, 50 k. The cartridges 50y, 50m, 50c, 50k contain or accommodate yellow toner (developer), magenta toner (developer), cyan toner (developer), and black toner (developer), respectively. Figure 2 is a side sectional view of the cartridge itself; fig. 3 and 4 are views for removing the cartridges 50y, 50m, 50c, 50k from the main assembly 100 of the apparatus.

[ general arrangement of electrophotographic image forming apparatus ]

As shown in fig. 1, the main assembly 100 of the apparatus, electrophotographic photosensitive drums (photosensitive drums) 30y, 30m, 30c, 30k are exposed to a laser beam 11 modulated by a laser scanner 10 in accordance with an image signal, so that an electrostatic latent image is formed on the surface. The electrostatic latent images are developed by the developing rollers 42 into toner images (developed images) on the respective surfaces of the photosensitive drums 30. By applying voltages to the transfer rollers 18y, 18m, 18c, 18k, the toner images of the respective colors formed on the photosensitive drums 30y, 30m, 30c, 30k are sequentially transferred onto the transfer belt 19. Thereafter, the toner image formed on the transfer belt 19 is transferred by the transfer roller 3 onto the recording material P fed by the feed roller 1 (feeding means). Thereafter, the recording material P is fed to a fixing unit 6, and the fixing unit 6 includes a driving roller and a fixing roller including a heater. Here, the toner image transferred onto the recording material P is fixed by applying heat and pressure to the recording material P. Thus, the recording material on which the toner image is fixed is discharged to the discharging portion 9 by the pair of discharging rollers 7.

[ Overall arrangement of Process cartridges ]

The cartridges 50y, 50m, 50c, and 50k of this embodiment will be described below with reference to fig. 1, 2, 5, and 22, 29, and 30. Since the cartridges 50y, 50m, 50c, 50k are the same except that the colors contained therein are different from each other, only the cartridge 50y will be described below.

The cartridge 50y includes the photosensitive drum 30, a process device capable of acting on the photosensitive drum 30. The processing device includes: a charging roller 32 serving as a charging means for charging the photosensitive drum 30; a developing roller 42 serving as a developing device that develops the latent image formed on the photosensitive roller 30; and/or a blade 33 serving as a cleaning means for removing the remaining toner remaining on the surface of the photosensitive drum 30. The cartridge 50y includes the drum unit 31 and the developing unit 41.

[ Structure of Drum Unit ]

As shown in fig. 2, 10, the drum unit 31 includes a photosensitive drum 30, a charging device 32, a cleaning device 33, a remaining toner containing portion 35, a drum frame 34, and covering members 36, 37. As shown in fig. 9, one longitudinal end of the photosensitive drum 30 is rotatably supported by the supporting portion 36b of the covering member 36. As shown in fig. 11 to 14, the other longitudinal end of the photosensitive drum 30 is rotatably supported by the supporting portion 37b of the covering member 37. The cover members 36, 37 are fixed to the drum frame 34 at opposite longitudinal ends of the drum frame 34. As shown in fig. 9 and 10, one longitudinal end of the photosensitive drum 30 has a connecting member 30a for receiving a driving force for rotating the photosensitive drum 30. When the cartridge 50y is mounted to the main assembly 100 of the apparatus, the connecting member 30a is engaged with the first main assembly connecting member 105 shown in fig. 4 and 30. The photosensitive drum 30 is rotated in the direction of an arrow u shown in fig. 2 by a driving force transmitted from a driving motor (not shown) provided in the main assembly 100 of the apparatus to the connecting member 30 a. The charging device 32 is supported on the drum frame 34, and is rotated by the photosensitive drum 30 in contact with the charging device 32. The cleaning device 33 is supported by the drum frame 34 and is in contact with the outer peripheral surface of the photosensitive drum 30. The cover members 36, 37 have support hole portions 36a, 37a, and the support hole portions 36a, 37a are used to rotatably (movably) support the developing unit 41.

[ Structure of developing Unit ]

As shown in fig. 2, the developing unit 41 includes a developing roller 42, a developing blade 43, a developing device frame 48, a supporting unit 45, and a covering member 46. The developing device frame 48 includes a toner accommodating portion 49 for accommodating toner to be supplied to the developing roller 42, and a developing blade 43 for adjusting the toner layer thickness of the peripheral surface of the developing roller 42. As shown in fig. 9, the bearing unit 45 is fixed to one longitudinal end side of the developing device frame 48, and rotatably supports the developing roller 42 having a developing roller gear 69 at an end thereof. The supporting unit 45 has a connecting member 67, an intermediate gear 68 for transmitting the driving force from the connecting member 67 to the developing roller gear 69. The covering member 46 is fixed to the longitudinal outer side of the support unit 45 so as to cover the connecting member 67 and the intermediate gear 68. The cover member 46 has a cylindrical portion 46b protruding beyond the surface of the cover member 46. The connecting member 67 is exposed through the inner opening of the cylindrical portion 46 b. Here, when the cartridge 50y is mounted in the main assembly 100 of the apparatus, the connecting member 67 is engaged with the second main assembly connecting member 106 shown in fig. 30, so that the driving force from a driving motor (not shown) provided in the main assembly 100 of the apparatus is transmitted.

[ Assembly of Drum Unit and developing Unit ]

As shown in fig. 9, 11 to 14, when the developing unit 41 and the drum unit 31 are assembled with each other, on one end side, the outer circumference of the cylindrical portion 46b is engaged with the support hole portion 36 a; and at the other end side, a protruding portion 48b provided protruding from the developing device frame 48 is engaged with the support hole portion 37 a. In this way, the developing unit 41 is rotatably supported with respect to the drum unit 31. As shown in fig. 2, the developing unit 41 is urged by an urging spring 95 (elastic member) so that the developing roller 42 rotates around the cylindrical portion 46b and the protruding portion 48b to contact the photosensitive drum 30. More specifically, the developing unit 41 is urged in the direction of arrow G by the urging force of the urging spring 95, so that the developing unit 41 receives the torque H around the cylindrical portion 46b and the protruding portion 48 b. Thereby, the developing roller 42 can be brought into contact with the photosensitive drum 30 with a predetermined pressure. The position of the developing unit 41 at this time is the "contact position".

As shown in fig. 10, the thrust spring 95 of this embodiment is provided at the following end portion: the end portion is opposed to one longitudinal end having the connecting member 30a for the photosensitive drum 30 and having the connecting member 67 for the developing roller gear 69. Due to this structure, the force g (fig. 6) from the first force application member 61 received by the first force receiving member 75 of the force receiving device 90 (which will be described later) provided on the one longitudinal end will generate a torque around the cylindrical portion 46b in the developing unit 41. In other words, at the one longitudinal end, the torque h thus generated effectively urges the developing roller 42 to the photosensitive drum 30 with a predetermined pressure. At the other end, a thrust spring 95 is used to urge the developing roller 42 to the photosensitive drum 30 with a predetermined pressure.

[ force-receiving device ]

As shown in fig. 2, the cartridge 50y has a force receiving means 90 for effecting contact and separation between the developing roller 42 and the photosensitive drum 30 in the main assembly 100 of the apparatus. As shown in fig. 9, 15, and 19, the force receiving device 90 includes a first force receiving member 75, a second force receiving member 70, and a spring 73 (urging means).

As shown in fig. 9, the first force receiving member 75 is attached to the support unit 45 by the engagement portion 75d of the first force receiving member engaging with the guide portion 45b of the support unit 45. On the other hand, the second force receiving member 70 is mounted to the support unit 45 by the shaft 70a of the second force receiving member engaging with the guide portion 45a of the support unit 45. The supporting unit 45 having the first force receiving member 75 and the second force receiving member 70 is thus fixed to the development accommodating portion 48, and then, as shown in fig. 10, the covering member 46 is fixed to cover the supporting unit 45 from the outside in the axial direction of the developing roller 42 of the supporting unit 45. In a state where the cartridge 50y is mounted to the main assembly 100 of the apparatus, the first force receiving member 75 and the second force receiving member 70 are located above the cartridge 50 y.

The operation of the force receiving device 90 will be described in detail later.

[ drawer type member of main assembly of electrophotographic image forming apparatus ]

The cartridge tray 13 as a drawer type member will be described below.

As shown in fig. 4, the cartridge tray 13 is linearly movable (inserted and extracted) in a substantially horizontal (D1, D2 direction) with respect to the main assembly 100 of the apparatus. More specifically, the cartridge tray 13 is movable between a mounting position shown in fig. 1, which is inside the main assembly 100 of the apparatus, and a drawn-out position shown in fig. 4, which is outside the main assembly 100 of the apparatus. As shown in fig. 4, the cartridges 50y, 50m, 50C, 50k are mounted on the cartridge tray 13 substantially vertically (arrow C) by the operator in a state where the cartridge tray 13 is at the drawn-out position. The cartridges 50y, 50m, 50c, 50k are arranged parallel to each other such that the longitudinal directions thereof (the axial directions of the photosensitive drum 30 and the developing roller 42) are substantially perpendicular to the moving direction of the cartridge tray 13. The cartridges 50y, 50m, 50c, 50k are caused to enter the main assembly 100 of the apparatus while being carried on the cartridge tray 13. At this time, the cartridges 50y, 50m, 50c, 50k move, and the photosensitive drums 30 maintain a certain distance (gap f2) from the intermediate transfer belt 19 disposed below these cartridges (fig. 5). When the cartridge tray 13 is located at the mounting position, the cartridges 50y, 50m, 50c, 50k are positioned at their positions by positioning portions 101a provided in the main assembly 100 of the image forming apparatus. The positioning portion will be described in detail later. Therefore, by making the cartridge tray 13 enter and close the door 12, the user can surely mount the cartridges 50y, 50m, 50c, 50k in the main assembly 100 of the apparatus. Therefore, the operability is improved compared with the structure in which the cartridges 50y, 50m, 50c, 50k are mounted in the main assembly 100 of the apparatus one by the user.

The operation of the cartridge tray 13 will be described below with reference to fig. 23 to 25 and fig. 36 to 38.

Here, the cartridge is omitted for simplifying the explanation of the operation of the cartridge tray 13.

The cartridge tray 13 is supported in a drawable manner with respect to the tray holding member 14. The tray holding member 14 is movable in association with the movement of the door 12 (opening and closing member). The door 12 is provided on the main assembly 100 of the apparatus and is rotatable about a rotation center 12 a.

When the cartridge is taken out of the main assembly 100 of the apparatus, the door 12 is moved from the closed position to the open position. As the door 12 moves, the engaging portion 15 provided on the door 12 moves clockwise about the rotation center 12 a. Then, as shown in fig. 24, the engaging portion 15 moves from the lower end 14c2 to the upper end 14c1 in the elongated hole 14c provided in the tray holding member 14. Along with this operation, the engaging portion 15 moves the holding member 14 in the direction z 1. At this time, as shown in fig. 25, the projecting portions 14d1, 14d2 projecting from the tray holding member 14 are guided by the guide slot or groove 107 provided in the main assembly 100 of the apparatus. As shown in fig. 26, the guide groove includes a horizontal portion 107a1, an inclined portion 107a2 continuous with the horizontal portion 107a1 and inclined upward, and a horizontal portion 107a3 continuous with the inclined portion 107a 2. Therefore, as shown in fig. 24, when the door 12 is moved to the open position, the protruding portions 14d1, 14d2 are guided in this order along the horizontal portion 107a1, the inclined portion 107a2, and the horizontal portion 107a 3. Therefore, the carriage holding member 14 moves in the direction z1 and moves away from the transfer belt 19 in the direction of arrow y 1. In this state, as shown in fig. 25, the cartridge tray 13 can be drawn in the direction of arrow D2 toward the outside of the main assembly 100 of the apparatus through the opening 80. Fig. 30 is a partially cut-away perspective view of this state.

The following will describe a case of mounting the cartridge into the main assembly 100 of the apparatus. With the door 12 in the open position shown in fig. 25, the cartridge tray 13 is caused to enter the main assembly 100 of the apparatus through the opening 80 in the direction of arrow D1. Thereafter, as shown in fig. 23, the door 12 is moved to the closed position. As the door 12 moves, the engaging portion 15 provided on the door 12 moves counterclockwise about the rotation center 12 a. Then, as shown in fig. 23, the engaging portion 15 is moved along the elongated hole 14c provided in the tray holding member 14 toward the lower end 14c2 of the elongated hole 14 c. Along with this operation, the engaging portion 15 moves the holding member 14 in the direction z 2. Therefore, as shown in fig. 23, when the door 12 is moved to the closed position, the projections 14d1, 14d2 are guided by the horizontal portion 107a3, the inclined portion 107a2, and the horizontal portion 107a1 in this order. Thus, the carriage holding member 14 moves in the direction z2, and moves toward the transfer belt 19 in the direction of the arrow y 2.

[ positioning of Process Cartridge with respect to the Main Assembly of an electrophotographic image Forming apparatus ]

The positioning of the cartridges 50y, 50m, 50c, 50k relative to the main assembly 100 of the apparatus will be described below with reference to fig. 5, 15, and fig. 19, 27, 29, 30.

As shown in fig. 30, there are provided positioning portions 101a for positioning the cartridges 50y, 50m, 50c, 50k in the main assembly 100 of the apparatus. The positioning portion 101a is provided such that the transfer belt 19 is disposed between the positioning portion 101a and the respective cartridges 50y, 50m, 50c, 50k with respect to the longitudinal direction. As shown in fig. 27 (a) and 27 (b), the first force application member 61 is rotatably supported by a support shaft 55 of the main assembly 100 of the apparatus, and the support shaft 55 is engaged with a support hole 61d at a position above the carriage holding member 14.

As shown in fig. 27 (a) and 27 (b), the first force application member 61 moves as the door 12 moves from the open position to the closed position. As shown in fig. 20, the projection 61f provided on the first force application member 61 pushes the projection 31a provided on the upper surface portion of the drum frame 34. Thereby, the cartridge 50y is urged in the direction of the arrow P (fig. 19), so that a portion to be positioned 31b (fig. 7) provided on the drum unit 31y is brought into abutment with a positioning portion 101a provided in the main assembly 100 of the apparatus, whereby the cartridge 50y is positioned in position (fig. 6). The same is done adjacent the opposite longitudinal end. The same operation is performed for the other cartridges 50m, 50c, and 50 k.

The mechanism for interlocking the first force application member 61 with the door 12 will be described below. The first force application member 61 is engaged with a connection member 62 that is interlocked with the door 12. As shown in fig. 15 to 19, the connecting member 62 includes a support hole 62c engaged with the support shaft 55, a hole 62a engaged with the protruding portion 61f, and a support pin 62b engaged with an elongated hole 14b (fig. 27 (b)) provided in the tray holding member 14. As shown in fig. 27, by the movement of the door 12 from the open position to the closed position, the tray holding member 14 is moved in the direction of arrow y2 (fig. 27). Thereby, the support pin 62b engaged with the elongated hole 14b also receives a force in the arrow y2 direction. Therefore, the connection member 62 rotates about the support hole 62c in the direction of arrow z (fig. 27). As shown in fig. 19, a spring 66 is provided between the first urging member 61 and the connecting member 62. The spring 66 is supported by the support shaft 55, and is in contact with a projection 62e provided on the connecting member 62 and a protruding portion 61f provided on the first force application member 61. Due to the urging force of the spring 66, the projection portion 61f urges the projection 31a provided on the drum frame 34 in the direction of the arrow P to position the cartridges 50y, 50m, 50c, 50k to the positioning portions 101a of the main assembly 100 of the apparatus.

As shown in fig. 21, the projection 31a may be directly urged by the spring 66. Therefore, the structure for interlocking the connecting member 62 with the door 12 is the same as that of fig. 15 to 20. When the door 12 is in the open position, one end 66b of the spring 66 engages with the hook 62e provided on the connection member 62, and the other end 66a of the spring 66 engages with the projection 62f provided on the connection member 62. By the door 12 moving from the open position to the closed position, the other end 66a becomes away from the projection 62f, and directly pushes the projection 31a to position the cartridges 50y, 50m, 50c, 50k to the positioning portion 101a of the main assembly 100 of the apparatus.

[ separating mechanism of main assembly of electrophotographic image forming apparatus ]

A mechanism for operating the force receiving device 90 provided on the cartridge 50y will be described below with reference to fig. 5 to 8 and fig. 11 to 19. Fig. 5 to 8 are sectional views of the cartridge as viewed in the axial direction of the photosensitive drum 30, and fig. 11 to 14 are perspective views as viewed from the non-driving side of the cartridge 50 y. The state shown in fig. 5 corresponds to the state shown in fig. 11 and the state shown in fig. 15. The state shown in fig. 6 corresponds to the state shown in fig. 12 and the state shown in fig. 16. The state shown in fig. 7 corresponds to the state shown in fig. 13, and the state shown in fig. 8 corresponds to the state shown in fig. 14.

As described in the foregoing, with the closing operation of the door 12 from the open position, the first force application member 61 moves about the support shaft 55 from the state of fig. 5, 11, and 15 to the state of fig. 6, 12, and 16. At this time, the first force application member 61 not only positions the cartridge 50y relative to the main assembly 100 of the apparatus but also acts on the first force receiving member 75 of the cartridge 50 y. More specifically, the pressing portion 61e of the first force application member 61 abuts the first pressed portion of the first force receiving member 75. Thereafter, the first force receiving member 75 pushes the cam surface 70c (third pushed portion) provided on the second force receiving member 70, whereby the second force receiving member 70 rotates about the shaft 70 a. Then, the second force receiving member 70 is moved from the standby position shown in fig. 5, 11, and 15 to the outside of the developing unit 41 of the cartridge 50y, i.e., away from the rotational axis 46b of the developing unit 41. With the structure shown in fig. 21, the protruding portion 62g protruding from the connecting member 62 functions as the first force application member 61.

The operation of the second force application member 60 will be described below with reference to fig. 28.

A driving force from a motor 110 (driving source) provided to the main assembly 100 of the apparatus is transmitted to a gear 112 through a gear 111. The gear 112 receiving the driving force rotates in the direction of the arrow L to rotate the cam portion 112a provided integrally with the gear 112 in the direction of the arrow L. The cam portion 112a is engaged with the offset force receiving portion 60b provided on the second force application member 60. Therefore, the second force application member 60 moves in the direction of the arrow E or B with the rotation of the cam portion 112 a.

Fig. 28 shows in (a) a case where the second force application member 60 is moved in the direction of the arrow E and the developing roller 42 and the photosensitive drum 30 are still in contact with each other (fig. 7). Fig. 28 shows in (B) a case where the second force application member 60 is moved in the direction of the arrow B and the second force receiving member 70 receives a force from the engagement rib 60 y. Thus, the developing unit 41 rotates (moves) about the rotation axis 46b, and therefore the developing roller 42 and the photosensitive drum 30 become separated from each other, and the position of the developing unit 41 at this time is the separation position.

As shown in fig. 15, the second force application member 60 has an elongated hole portion 60c to allow the support shaft 55 to move, with the first force application member 61 being rotatably provided on the support shaft 55. Therefore, even when the second biasing member 60 moves in the direction of the arrow B (fig. 8) or the direction of the arrow E (fig. 7), the second biasing member 60 can move without being disturbed by the first biasing member 61. Similarly to the first force application member 61, the second force application member 60 is disposed facing the moving path of the cartridges so as to be located above the cartridges 50y, 50m, 50c, 50k entering the main assembly 100 of the apparatus on the cartridge tray 13. In the step of moving the cartridges 50y, 50m, 50c, 50k into the main assembly 100 of the apparatus, the second force receiving member 70 is held at the standby position (fig. 15). Therefore, the first force application member 61 and the second force application member 60 can be brought very close to the cartridges 50y, 50m, 50c, 50k as long as they do not interfere with the cartridges, so that a wasted space can be eliminated. Therefore, the main assembly 100 of the apparatus can be downsized with respect to the vertical direction and the longitudinal direction of the cartridge 50y (the axial direction of the photosensitive drum 30).

The operation will be described in detail below.

Mounting process cartridge to main assembly of electrophotographic image forming apparatus and operation of force receiving means

Description will be made next regarding a series of operations from mounting the cartridges 50y, 50m, 50c, 50k to the main assembly 100 of the electrophotographic image forming apparatus to separating the developing roller 42 from the photosensitive drum 30.

As shown in fig. 4, the cartridges 50y, 50m, 50C, 50k are mounted from the top in the direction of arrow C to the cartridge tray 13 drawn out to the drawn-out position.

By moving the cartridge tray 13 in the direction of the arrow D1, the cartridges 50y, 50m, 50c, 50k enter the main assembly 100 of the apparatus through the opening 80. Therefore, in this embodiment, the cartridges 50y, 50m, 50c, 50k are inserted into the main assembly 100 of the apparatus in a direction substantially perpendicular to the axial direction of the photosensitive drum 30.

As shown in fig. 31, 32, the cartridge 50y is mounted in the cartridge tray 13 at the most downstream position with respect to the insertion or entering direction. The cartridge 50y advances from the upstream side to the downstream side below the first urging members 61k, 61c, 61m and the engagement ribs 60k, 60c, 60m of the second urging member 60, which can act on the cartridges 50m, 50c, 50 k.

The cartridge 50m is mounted on the cartridge tray 13 at a second position from the downstream side with respect to the entering direction. The cartridge 50m advances from the upstream side to the downstream side below the engagement ribs 60k, 60c of the first urging members 61k, 61c and the second urging member 60, which can act on the cartridges 50c, 50 k.

The cartridge 50c is mounted on the cartridge tray 13 at a third position from the downstream side with respect to the entering direction. The cartridge 50c passes from the upstream side to the downstream side below the engagement rib 60k of the first urging member 61k and the second urging member 60 which can act on the cartridge 50 k.

The cartridge 50k on the cartridge tray 13, which is the most upstream with respect to the entering direction, enters from the upstream side to the downstream side so that the second force receiving member 70 thereof passes below the first force application member 61 which can act on the cartridge 50 k.

The same applies to the cartridges 50y, 50m, 50c, in which the second force receiving member 70 passes from the upstream side to the downstream side below the first force application member 61 k.

That is, when the process cartridge is inserted with the second force receiving member 70 projected, the first force application member 61 and the second force application member 60 must be located at upper positions to avoid the second force receiving member 70 from interfering with the first force application member 61 and the second force application member 60. However, if the second force receiving member 70 is in the standby position, the first force application member 61 and the second force application member 60 can be disposed close to the cartridges 50y, 50m, 50c, 50k without considering the degree of protrusion of the second force receiving member 70. Therefore, the size in the vertical direction of the main assembly 100 of the apparatus can be reduced. Further, as shown in fig. 31 and 32, the force receiving device 90, the first force application member 61, and the second force application member 60 are positioned such that: the force receiving device 90 overlaps the first force application member 61 and the second force application member 60 in the axial direction of the drum, and therefore, the longitudinal dimension of the cartridge can be reduced.

When the cartridge tray 13 is inserted into the main assembly 100 of the apparatus, a gap f1 remains between the second force application member 60 and the force receiving device 90, as shown in fig. 5. Further, a gap f2 remains between the photosensitive drum 30 and the transfer belt 19. Therefore, the cartridges 50y, 50m, 50c, 50k can enter without interfering with the main assembly 100 of the apparatus.

Therefore, as shown in fig. 23, by moving the door 12 to the closed position, the carriage holding member 14 is moved in the direction (arrow y2) to approach the transfer belt 19. The vertical component of the movement distance in the direction of the arrow y2 is f 2. Thus, as shown in fig. 6, the cartridges 50y, 50m, 50c, 50k also move so that the surfaces of the photosensitive drums 30 are in contact with the surface of the transfer belt 19. In this case, the gap f1 between the force receiving device 90 and the second force application member engaging portion 60 is enlarged to f1+ f 2.

Further, by moving the door 12 to the closed position, the first force application member 61 is moved so that the projection 31a provided on the upper surface portion of the drum frame 34 is pushed by the protruding portion 61 f. Thereby, as shown in fig. 6, the positioning portions 31b of the cartridges 50y, 50m, 50c, 50k abut to the corresponding positioning portions 101a provided on the main assembly 100 of the apparatus, and thus the cartridges 50y, 50m, 50c, 50k are positioned in the main assembly 100 of the apparatus.

The cartridges 50y, 50m, 50c, 50k are prevented from moving in the direction of arrow a (fig. 1) in the main assembly 100 of the apparatus by engaging the shaft 36d provided on the covering member 36 shown in fig. 10 with the rotation preventing portion 13a provided on the cartridge tray 13.

The urging portion 61e of the first force application member 61 contacts and urges the urged portion 75a (fig. 15) of the first force receiving member 75 positioned at the first position (fig. 15). Accordingly, the first force receiving member 75 moves in the direction of the arrow r to be positioned at the second position (fig. 16).

In the second position, the urging portion 75b urges the cam surface 70c of the second force receiving member 70, as shown in fig. 15. In this way, the second force receiving member 70 rotates about the axis of the shaft 70a from the standby position to a position outside the developing unit 41 of the cartridges 50y, 50m, 50c, 50k, that is, in a direction away from the rotation axis 46b of the developing unit 41.

At this time, however, the upper surface 70 of the second force receiving member 70 interferes with the lower surface of the engagement rib 60y of the second force application member 60 located at the home position, whereby the movement of the second force receiving member 70 is regulated by the engagement rib 60y (fig. 6, 12). The position of the second force receiving member 70 at this time is referred to as a regulation position.

Here, this position is made the original position for the following reasons: after the cartridges 50y, 50m, 50c, 50k are mounted in the main assembly 100 of the apparatus, the state is as shown in fig. 8 until the image forming operation is performed. More specifically, the second force application member 60 has been moved in the direction of the arrow B, and therefore the engagement rib 60y pushes the second force receiving member 70. In this state, the photosensitive drum 30 and the developing roller 42 are separated from each other. In the state shown in fig. 8, the cartridges 50y, 50m, 50c, 50k are detached from the main assembly 100 of the apparatus. Therefore, when the cartridges 50y, 50m, 50c, 50k are mounted to the main assembly 100 of the apparatus again, the second force application member 60 is in the position shown in fig. 8, and therefore, when the second force receiving member 70 is moved from the standby position, it is in contact with the rib 60 y.

As shown in fig. 8, the direction of the force (arrow J) received by the first force receiving member 75 from the first force application member 61 is substantially opposite to the direction of the force received by the second force receiving member 70 from the second force application member 60. The surface of the second force receiving member 70 which receives the force from the second force application member 60 faces the direction in which the cartridges 50y, 50m, 50c, 50k enter the main assembly 100 of the apparatus. By selecting the direction of the received force, when the second force receiving member 70 receives the force from the second force application member 60, it is possible to ensure that the developing unit 41 moves efficiently and surely with respect to the drum unit 31. In addition, the state in which the photosensitive drum 30 and the developing roller 42 are separated can be stably maintained.

However, even if the movement of the second force receiving member 70 is restricted by the engaging rib 60y, the force receiving device 90 including the second force application member 60 and the second force receiving member 70 is not damaged. As shown in fig. 22(a), since the movement of the second force receiving member 70 is regulated, the movement of the pushing portion 75b for pushing the cam surface 70c is also regulated. Even if the pressing portion 61e of the first force application member 61 further presses the pressed portion 75a, the elastic portion 75c in the form of an arch provided on the first force receiving member 75 is bent (elastically deformed). Therefore, even if the movement of the second force receiving member 70 is regulated, the force receiving device 90 is not damaged.

Also, when the second force application member 60 is moved from the position of fig. 6, 12 in the direction of the arrow E shown in fig. 7, 13, the second force receiving member 70 is moved to the outside of the cartridge 50y to enter the moving path of the engaging rib 60 y. The position of the second force application member 60 at this time is called a projecting position. Therefore, when the second force application member 60 is at the projecting position, it projects beyond the above-described standby position. In the projected position, the second force receiving member 70 projects more than the gap f1+ f2 so as to be engaged with the second force application member 60. After the cartridges 50y, 50m, 50c, 50k are mounted to the main assembly 100 of the apparatus, the operation of the second force application member 60 is performed before the image formation.

Then, as shown in fig. 8, 14, the second force application member 60 is moved in the direction of the arrow B so that the side surface 70B (which is the second pushed portion of the second force receiving member 70 entering the moving path) receives the force from the engagement rib 60 y. Thus, the developing unit 41 rotates (moves) about the rotation axis 46b, so that the developing roller 42 is separated from the photosensitive drum 30 by a gap α. The second force receiving member 70 receives a force from the second force receiving member 70 in the protruding position. Therefore, the distance to the rotation axis 46b of the developing unit 41 can be made larger than in a structure in which the second force receiving member is moved toward the process cartridge and engaged with the developing unit to separate the developing device. Therefore, the driving torque required for separating the developing roller 42 from the photosensitive drum 30 can be made small.

Further, by the movement of the second force application member 60 in the arrow B direction, the position at which the first force receiving member 75 is pushed by the first force application member 61 and the position at which the second force receiving member 70 receives the force from the engagement rib 60y are changed with respect to the horizontal direction. In other words, the relationship between the distance I shown in fig. 7 and the distance II shown in fig. 8 is the distance I > the distance II. This change in distance is regulated by the elastic portion 75c provided on the second force receiving member 70. As shown in fig. 22(a), the elastic portion 75c is in the form of a flexible arch structure. A spring 76 as an elastic member is provided inside the elastic portion 75 c. The spring 76 prevents the bending of the elastic portion 75c more than necessary and serves to restore the bent elastic portion 75 c. The elastic portion 75c is not necessarily an arcuate structure, and the elastic member may be a simple elastic member.

To effect the image forming operation, the developing roller 42 is brought into contact with the photosensitive drum 30 by moving the second force application member 60 in the direction of the arrow E. Thereby, as shown in fig. 7 and 13, the second force receiving member 70 enters a state of not receiving a force from the engagement rib 60 y. Therefore, the developing roller 42 and the photosensitive drum 30 are brought into contact with each other by the urging force of the spring 95 provided between the developing unit 41 and the drum unit 31, so that the cartridges 50y, 50m, 50c, 50k become capable of forming images. In this case, before the developing roller 42 comes into contact with the photosensitive drum 30, the photosensitive drum 30 rotates, and the developing roller 42 also receives a driving force from the main assembly 100 of the apparatus and rotates. This is achieved by providing the connecting portion 67a coaxially with the cylindrical portion 46b, so that the position of the connecting portion 67a does not change even if the developing unit 41 moves around the cylindrical portion 46 b. Therefore, before the developing roller 42 and the photosensitive drum 30 contact each other, the photosensitive drum 30 and the developing roller 42 rotate. Therefore, when the developing roller 42 starts to contact the photosensitive drum 30, the speed difference between the photosensitive drum 30 and the outer circumferential surface of the developing roller 42 can be made small, and therefore, the abrasion of the photosensitive drum 30 and the developing roller 42 can be reduced. When the image formation is completed, as described previously, by moving the second force application member 60 in the direction of the arrow B, the developing roller 42 and the photosensitive drum 30 are separated from each other. After the separation, the rotation of the developing roller 42 and the photosensitive drum 30 is stopped. Therefore, the speed difference between the peripheral surfaces of the photosensitive drum 30 and the developing roller 42 is reduced, and therefore, the abrasion of the photosensitive drum 30 and the developing roller 42 can be reduced. Therefore, the image quality can be improved.

The elastic portion can be replaced with the structure shown in fig. 33, 34, 35. Here, the force receiving device 190 includes a first force receiving member 179 and a second force receiving member 178. As shown in fig. 34, 35, the first force application member 165 has a sliding portion 165a (inclined surface), and the first force receiving member 179 has a sliding portion 179a (inclined surface). Fig. 33 shows a state before the first force application member 165 moves. Fig. 34 shows a state in which the second force receiving member 178 protrudes from the cartridge 150y due to the first force application member 165 moving to abut against the first force receiving member 179. Fig. 35 shows a state after the second force application member 164 is moved in the direction of the arrow E.

Such a change in the distance between the first force receiving member 179 and the second force receiving member 178 shown in fig. 34, 35 from the distance I to the distance II can be achieved due to the slidability between the sliding portion 179a and the sliding portion 165a and the slidability of the first force receiving member 179 in the direction of the arrow F shown in fig. 35.

In the cartridge 50y used to describe this embodiment, the developing unit 41 is rotatable relative to the drum unit 31 in order to bring the developing roller 42 and the photosensitive drum 30 into contact with and apart from each other. However, fig. 36 shows an alternative structure in which the guided portion 544 is in the form of a square column structure, and the drum unit 531 has an elongated hole 536a which is engageable with the guided portion 544, wherein the developing unit 541 is slidable with respect to the drum unit 531.

More specifically, as shown in fig. 37, when the second force application member 560 does not act on the second force receiving member 570, the developing roller 542 is urged by a thrust spring (not shown) (elastic member) to bring the developing roller 542 into contact with the photosensitive drum. Then, as shown in fig. 38, the second force application member 560 is moved in the direction of the arrow B to act on the second force receiving member 570. Thereby, the developing unit 541 slides in the direction H relative to the drum unit 531, so that the developing roller 542 and the photosensitive drum 530 are separated by the gap g. Similar to the first embodiment, the force-receiving device 590 includes a first force-receiving member 575 and a second force-receiving member 570.

Next, an operation for taking out the cartridges 50y, 50m, 50c, 50k from the main assembly 100 of the apparatus will be described.

As the door 12 moves from the closed position to the open position, the first force application member 61 moves from the position of fig. 6 and 12 to the position of fig. 5 and 11. As a result, the first force receiving member 75 is no longer urged by the first urging member 61, and therefore the first force receiving member 75 moves from the state shown in fig. 6 and 12 to the state shown in fig. 5 and 11. More specifically, the second force receiving member 70 is no longer urged by the urging portion 75b of the first force receiving member 75. As shown in fig. 5, the second force receiving member 70 is also returned to the standby position (non-operating position) about the shaft 70a in the direction of arrow a by the force of the spring 73 shown in fig. 19.

As the door 12 moves from the closed position to the open position, the carriage holding member 14 rises away from the transfer belt 19, as shown in fig. 3, 4. Thereby, the cartridges 50y, 50m, 50c, 50k are raised, and therefore, the photosensitive drums 30 are separated from the transfer belt 19.

As described previously, the second force receiving member 70 for moving the developing unit 41 is configured such that: when the cartridges 50y, 50m, 50c, 50k are mounted to the main assembly 100 of the apparatus and the door 12 is moved to the closed position, the second force receiving member 70 projects outward from the developing unit 41. Therefore, the cartridges 50y, 50m, 50c, 50k can be reduced in size. Further, since the mounting is performed with the second force receiving member 70 in the standby position, the space required in the main assembly 100 of the apparatus for moving the cartridges 50y, 50m, 50c, 50k can be small. In other words, the size of the opening 80 may be small, and the first force application member 61 and the second force application member 60 may be close to the cartridges 50y, 50m, 50c, 50 k. Therefore, the size in the vertical direction of the main assembly 100 of the apparatus can be reduced. Further, when viewed in the vertical direction of the main assembly 100 of the apparatus, as shown in fig. 31, 32, the force receiving means 90 overlaps the first force application member 61 and the second force application member 60 in the drum axial direction, and therefore, the longitudinal dimension of the cartridge can be reduced.

When the cartridges 50y, 50m, 50c, 50k are operated by the user or when they are transported, the second force receiving member 70 can be placed in the standby position, and therefore the second force receiving member 70 is not easily damaged.

(second embodiment)

In the first embodiment, the cartridges 50y, 50m, 50c, 50k are mounted to the main assembly 100 of the apparatus in a direction substantially perpendicular to the axis of the photosensitive drum 30. In embodiment 2, the cartridges 450y, 450m, 450c, 450k are mounted to the main assembly of the electrophotographic image forming apparatus (main assembly of the apparatus) 401 in a direction substantially parallel to the axial direction of the electrophotographic photosensitive drum (photosensitive drum) 430. In the following description, points different from the first embodiment will be mainly described.

[ general arrangement of electrophotographic image forming apparatus ]

As shown in fig. 39, 41, the main assembly 401 of the apparatus is equipped with cartridges 450y, 450m, 450c, 450k in a direction substantially parallel to the axial direction (longitudinal direction) of the photosensitive drum 430. In this embodiment, the cartridges 450y, 450m, 450c, 450K are mounted in the mounting member 480c provided in the main assembly 401 of the apparatus in the direction of arrow K. The cartridges 450y, 450m, 450c, 450k contain yellow, magenta, cyan, and black toner particles (developers), respectively.

The cartridges 450y, 450m, 450c, 450k each have a force receiving device 490, the force receiving device 490 having a first force receiving member 475 and a second force receiving member 470. On the rear side of the main assembly 401 of the apparatus with respect to the cartridge entering direction, there are provided a first force application member 461 and a second force application member 460 which are capable of acting on the first force receiving member 475 and the second force receiving member 470, respectively. As shown in fig. 42, the main assembly 401 of the apparatus has an opening 408 for allowing the cartridges 450y, 450m, 450c, 450k to enter the main assembly 401 of the apparatus, and a door 412 movable between a closed position closing the opening 408 and an open position opening the opening 408. The door 412 is rotatable about a rotation axis 412 a. As shown in fig. 45, the mounting member 480 integrally includes: a holding portion 480c for holding the cartridges 450y, 450m, 450c, 450k, respectively, an operating member 480b for moving the first force application member 461, and a connecting portion 480a for connecting the operating member 480b and the door 412 to each other. As shown in fig. 42, the connecting portion 480a and the door 412 are connected to each other by engagement between an elongated hole 480g provided on the connecting portion 480a and a protrusion 412b provided on the door 412.

Therefore, as the door 412 moves from the open position to the closed position in the direction of the arrow m, the projections 480d, 480e provided on the connecting portion 480a move along the guide grooves 401a, 401b provided on the main assembly 401 of the apparatus, as shown in fig. 42. Therefore, the holding portion 480c integral with the operating member 480b moves in the direction of the arrow n. Accordingly, the photosensitive drums 430 of the cartridges 450y, 450m, 450c, 450k supported on the holding portion 480c are moved from the position separated from the transfer belt 419 shown in fig. 47 to the position in contact with the transfer belt 419 shown in fig. 48. Meanwhile, a portion to be positioned 431b provided on the drum unit 431 abuts against a positioning portion 401a provided in the main assembly 401 of the apparatus, whereby the cartridges 450y, 450m, 450c, 450k are correctly positioned.

Each of the cartridges 450y, 450m, 450c, 450k is prevented from moving in the direction of arrow a in fig. 39 in the main assembly 401 of the apparatus by engaging the shaft 436d provided on the cover member 436 with the rotation preventing portion 485a provided on the main assembly 401 of the apparatus.

When the cartridges 450y, 450m, 450c, 450k are dismounted from the main assembly 401 of the apparatus, the operation thereof is opposite to the mounting operation.

[ operation of the first force application member and the second force application member ]

The operation of the first force application member 461 will be described below with reference to fig. 40 to 45. Similarly to the first embodiment, the first force application member 461 is engaged with the connecting member 462 in conjunction with the operation of the operating member 480 b. The structure of the connecting member 462 is the same as that in the first embodiment. Fig. 40 and 42 (a) and fig. 43 show a state in which the door 412 is in the open position and the operating member 480b is in the upper position. Fig. 41, 42 (b) and 44 show a state in which the door 412 is in the closed position. When the door 412 is closed, the operating member 480b moves downward (in the direction of arrow n). As shown in fig. 43, 44, the projection 462b provided on the connecting member 462 engages with the elongated hole 480h provided in the mounting member 480. Therefore, the connecting member 462 rotates about the rotation center 461d in the direction of the arrow Q along with the movement of the operating member 480 b. Similar to the first embodiment, the first force application member 461 rotates with the rotation of the connection member 462. When the door 412 is moved from the closed position to the open position, the operation is reversed from that described above. The other operations are the same as the first embodiment.

The operation of the second force application member 460 is the same as that of the first embodiment.

[ Overall arrangement of Process cartridges ]

The structure of the process cartridge of this embodiment will be described below. The structures of the cartridges 450y, 450m, 450c, and 450k are the same, and therefore only the cartridge 450y will be described below with reference to fig. 46.

The cartridge 450y includes the photosensitive drum 430, a process device capable of acting on the photosensitive drum 30. The processing device includes: a charging roller 432 serving as a charging means for charging the photosensitive drum 430; a developing roller 442 serving as a developing device that develops the latent image formed on the photosensitive drum 430; and/or a blade 433 serving as a cleaning means for removing the remaining toner remaining on the surface of the photosensitive drum 430. The cartridge 450y includes a drum unit 431 and a developing unit 441.

The structures of the drum unit 431 and the developing unit 441 and the connection structure between the drum unit 431 and the developing unit 441 are the same as those of the first embodiment.

[ force-receiving device ]

Similarly to the first embodiment, as shown in fig. 47, the cartridge 450y includes a force receiving device 490 for bringing the developing roller 442 and the photosensitive drum 430 into contact with each other and for separating them from each other. The specific structure thereof is the same as that shown in fig. 9, 15 to 19. As shown in fig. 47, the force receiving device 490 of this embodiment includes a first force receiving member 475, a second force receiving member 470, and a spring (not shown) as urging means.

[ separating mechanism of main assembly of electrophotographic image forming apparatus and urging mechanism for process cartridge ]

Fig. 49 shows a state after the second force application member 460 is moved from the home position (fig. 48) in the direction of arrow E, in which the developing roller 442 and the photosensitive drum 430 are still in contact with each other. Fig. 50 illustrates a state after the second force application member 460 is moved in the direction of arrow B, in which the developing roller 442 and the photosensitive drum 430 are separated from each other. Similar to the first embodiment, the second force application portion 460 has an elongated hole portion 460c for avoiding the rotational axis 461d of the first force application member 461. Even when the second force application portion 460 is moved in the direction of the arrow E or the arrow B, the second force application member 460 can be moved without interfering with the first force application member 461.

As shown in fig. 39, 40, the first force application member 461 and the second force application member 460 are provided above the cartridges 450y, 450m, 450c and 450k entering the main assembly 401 of the apparatus. While the cartridges 450y, 450m, 450c, and 450k are in the process of entering the main assembly 401 of the apparatus, the second force receiving member 470 is held at the standby position.

Also in this embodiment, when the cartridges 450y, 450m, 450c, and 450k are mounted to the main assembly 401 of the apparatus and the door 412 is moved to the closed position, the second force receiving member 470 projects to the outside of the developing unit 441. In this way, since the cartridges 450y, 450m, 450c, and 450k are inserted when the second force receiving member 470 is in the standby position, the space required for the cartridges 450y, 450m, 450c, and 450k to enter can be made small, and thus the cartridges 450y, 450m, 450c, and 450k can be reduced in size. In other words, the size of the opening 408 may be small, and the first force application member 461 and the second force application member 460 can be close to the cartridges 450y, 450m, 450c, and 450 k. The size in the vertical direction of the main assembly 401 of the apparatus can be reduced. Since the arrangement is such that the force receiving device 490 overlaps with the first force application member 461 and the second force application member 460 in the axial direction of the drum when viewed in the vertical direction, the longitudinal dimension of the cartridge can be reduced.

When the cartridges 450y, 450m, 450c, 450k are operated by a user or when they are transported, the second force receiving member 470 can be disposed at the standby position, and thus the second force receiving member 470 is not easily damaged.

(third embodiment)

This embodiment relates to a modification of the force-bearing device.

This embodiment will also be described below with the yellow cartridge 250y containing yellow developer as an exemplary cartridge.

As shown in fig. 51 to 54, the developing unit 241 has a force receiving member 277 (force receiving device).

The force receiving member 277 includes a shaft portion 277c rotatably supported on the developing device frame 248, a first force receiving portion 277a on which the first force application member 261 can act, and a second force receiving portion 277b on which the second force application member 263 can act. The force receiving member 277 is integrally constituted by a first force receiving portion and a second force receiving portion. The spring 298 has one end fixed to the force receiving member 277 and the other end fixed to the developing device frame 248. The force receiving member 277 is held in the state shown in fig. 51 by a spring 298.

As shown in fig. 52, similarly to the first embodiment, the first force application member 262 is brought into contact with the first force receiving portion 277a of the force receiving member 277 by the movement of the door (not shown) from the open position to the closed position. Thus, the force receiving member 277 rotates about the shaft 277c in the direction of the arrow S shown in fig. 52. The second force receiving portion 277b of the force receiving member 277 moves toward the outside of the developing unit 241.

Thereafter, as shown in fig. 53, the second force application member 263 is moved in the direction of arrow B by the driving force from the main assembly of the apparatus to contact the second force receiving portion 277B of the force receiving member 277. Further, when the second force application member 263 is moved in the direction of the arrow B, the developing unit 241 rotates about the connecting portion 246B relative to the drum unit 231, whereby the developing roller 242 is separated from the electrophotographic photosensitive drum 230 by a gap γ. At this time, as shown in fig. 53, the portion to be locked 277d of the force receiving member 277 is in contact with the locking portion 248a of the developing device frame 248 to regulate the movement of the force receiving member 277 in the arrow S direction as shown in fig. 52. Therefore, the developing unit 241 rotates relative to the drum unit 231 by the movement of the second force application member 263 in the direction of the arrow E. By the movement of the second force application member 263 in the direction of the arrow B, the first force receiving portion 277a of the force receiving member 277 slides on the free end portion 262a of the first force application member 262, and the free end portion 262a is deformed from the shape shown by the solid line to the shape shown by the broken line in fig. 54. To achieve such sliding and deformation, the free end portion 262a of the first force application member 262 can be elastically deformed. Further, the first force receiving portion 277a constitutes a slide surface that is slidable relative to the first force application member 262.

Even if the second force application member 263 is moved in the direction of the arrow B in the state shown in fig. 53, the elastically deformable property of the free end portion 262a of the first force application member 262 ensures the urging of the force receiving member 277 against the locking portion 248 a.

As for the contact between the developing roller 242 and the photosensitive drum 230, the movement of the second force application member 263 in the arrow E direction in fig. 53 from the state shown in fig. 53, the movement of the second force receiving member 277 by the second force application member 263 is realized. By the urging force of the spring 295, the developing unit 241 rotates to bring the developing roller 242 into contact with the photosensitive drum 230.

In this embodiment, the structure other than the force receiving member 277 is the same as that of the cartridge 50y described in the first embodiment. The operation of the first force application member 261 in this embodiment is the same as that of the first force application member 61 of the first embodiment or the first force application member 461 of the second embodiment.

As previously mentioned, in the force receiving device of this embodiment, the number of parts is less than the number of parts of the force receiving device 90 of the first embodiment.

(fourth embodiment)

This embodiment relates to a modification of the force-bearing device.

This embodiment will also be described below with the yellow cartridge 250y containing yellow developer as an exemplary cartridge. As shown in fig. 55 to 58, the developing unit 341 has a force receiving device 370. The force receiving device 370 includes a first force receiving member 370a, a second force receiving member 370b, a first spring 370c, and a second spring 370 d. The force receiving device 370 is movably supported in a guide 341a, and the guide 341a is provided in the developing device frame 348. The second spring 370d is provided between the locking portion 341c provided at one end of the guide 341a and the locking portion 370e provided on the second force receiving member 370 b. The first spring 370c is disposed between the first force receiving member 370a and the second receiving member 370 b.

When the door (not shown) is in the open position, the second force receiving member 370b is retracted to the following position (standby position) due to the urging force of the second spring 370 d: in this position, as shown in fig. 55, the locking portion 370e contacts the second locking portion 341b provided in the guide 341 a. At this time, a gap f1 is formed between the second force receiving portion 370b and the second force application portion 360 provided to the main assembly side of the apparatus. In other words, since the second force receiving member 370b does not receive a force from the second force application member 360, the photosensitive drum 330 and the developing roller 342 contact each other.

Similarly to the first embodiment, by the movement of the door (not shown) from the open position to the closed position, as shown in fig. 56, the first force application member 361 is brought into contact with the first pushed portion 370a1 of the first force receiving member 370 a. Thus, the second force receiving member 370b is urged by the spring 370c, so that the second force receiving member 370b is moved to the outside of the developing unit 241 (arrow P). At this time, the second force application member 360 comes into contact with the upper surface 370b1 of the second force receiving member 370b to regulate further movement. However, since the spring 370c is elastically deformed, even if the first force application member 361 continuously presses the first force receiving member 370a with the movement of the second force receiving member 370b regulated, the force receiving device 370 is not damaged.

As shown in fig. 57, when the second force application member 360 is moved in the direction of the arrow E, the second force receiving member 370b is further moved into the moving path of the second force application member 360 due to the urging force of the spring 370 c.

Then, as shown in fig. 58, by the movement of the second force application member 360 in the arrow B direction, the side surface 370B2 (second pushed portion) provided on the second force receiving member 370B receives the force from the second force application member 360. Further, when the second force application member 360 is moved in the direction of arrow E, the developing unit 341 rotates about the connecting portion 346b relative to the drum unit 331, whereby the developing roller 342 is separated from the electrophotographic photosensitive drum 330 by a gap δ. Here, the position at which the first force receiving member 370a is pushed by the first force application member 361 is fixed, and the second force receiving member 370B is moved due to the movement of the second force application member 360 in the arrow B direction shown in fig. 58. Therefore, the distance I between the first force receiving member 370a and the second force receiving member 370b and the distance II between the first force receiving member 370a and the second force receiving member 370b satisfy the distance I > distance II. In the force receiving device 370 of this embodiment, the change in distance can be adjusted by the spring 370c and the sliding movement of the first force application member 361 with respect to the first force receiving member 370 a.

The second force receiving member 370b is allowed to move by the second force application member 360 moving in the direction indicated by the arrow E in fig. 57 from the position shown in fig. 58. Similarly to the first embodiment, the developing roller 342 and the photosensitive drum 330 are in contact with each other by the urging spring 395 provided on the cartridge 350 y.

Also in this embodiment, the structure other than the force receiving device 370 is the same as that of the cartridge 50y in the first embodiment. The operation of the first force application member 361 in this embodiment is the same as that of the first force application member 61 in the first embodiment or the first force application member 461 in the second embodiment.

(fifth embodiment)

This embodiment relates to a modified example of the support structure of the force-receiving device (fig. 59, 60).

This embodiment will also be described with the yellow cartridge 650y containing yellow developer as an exemplary cartridge.

The cartridge 650y has a force receiving device 690 for contact and separation between the developing roller 642 and the photosensitive drum 630. Similar to the first embodiment, the force-receiving device 690 includes first and second force-receiving members 675, 670 shown in fig. 59, 60. The first force receiving member 675 is mounted on the drum frame 634 by engaging the engaging portion 675d provided on the first force receiving member 675 with the guide portion 638 of the drum frame 634. The first force receiving member 675 mounted on the drum frame 634 is prevented from being detached from the drum frame 634 by the regulating portion 639 provided on the drum frame 634.

The shaft 670a of the second force receiving member 670 is engaged with the guide portion 645a provided on the bearing unit 645. The bearing unit 645 including the second force receiving member 670 is fixed to one longitudinal end of the developing device frame 648, and rotatably supports the developing roller 642 having the developing roller gear 669 at the end. The bearing unit 645 has a connecting member 667 for receiving a driving force from a driving motor (not shown), and an intermediate gear 668 for transmitting the driving force from the connecting member 667 to a developing roller gear 669, similarly to the first embodiment. A covering member 646 is fixed to the longitudinal outside of the bearing unit 645 so as to cover the connecting member 667 and the intermediate gear 668. The cover member 646 has a cylindrical portion 646b protruding beyond the surface of the cover member 646. The connecting portion 667 is exposed through the inner opening of the cylindrical portion 646 b.

[ Assembly of Drum Unit and developing Unit ]

As shown in fig. 59, 60, when the developing unit 641 and the drum unit 631 are assembled, at one end, the outer circumference of the cylindrical portion 646b is engaged with the support hole portion 636 a. On the other hand, at the other end, the support hole portion 637a is engaged with a protruding portion 648b provided protruding from the developing device frame 648. The cover member 37 in the first embodiment shown in fig. 11 to 14 corresponds to the cover member 637 of this embodiment, and the support hole portion 37a shown in fig. 11 to 14 corresponds to the support hole portion 637a of this embodiment. The protruding portion 48b provided protruding from the developing device frame 48 in the first embodiment corresponds to the protruding portion 648b provided protruding from the developing device frame 648 in this embodiment.

Thus, the developing unit 641 is rotatably supported on the drum unit 631. Fig. 60 shows a cartridge 650y in which the developing unit 641 and the drum unit 631 have been combined with each other. This assembly enables the urging portion 675b of the first force receiving member 675 to act on the cam surface 671 (third urged portion) provided on the second force receiving member 670, similarly to the first embodiment, and enables contact and separation between the electrophotographic photosensitive drum 630 and the developing roller 642, similarly to the first embodiment. Therefore, the advantageous effects similar to the first embodiment can be provided.

(sixth embodiment)

This embodiment relates to a modification of the force-bearing device.

This embodiment will also be described with the yellow cartridge 750y containing yellow developer as an exemplary cartridge. As shown in fig. 61 to 63, the developing unit 74 has a force receiving device 790. The force-receiving device 790 includes a first force-receiving member 775 and a second force-receiving member 770. The first force receiving member 775 includes a support portion 775c rotatably supported on the developing device frame 748.

Similar to the first embodiment shown in fig. 15 to 19, the second force receiving member 770 is normally urged by urging means (not shown) to provide the state shown in fig. 61. In other words, since the second force receiving member 770 does not receive a force from the second force application member 760, the photosensitive drum 730 and the developing roller 742 contact each other. Similarly to the first embodiment, by the movement of the door (not shown) from the open position to the closed position, the first force application member 761 is brought into contact with the first urged portion 775a of the first force receiving member 775 from the top side, as shown in fig. 62. Thereby, the first force receiving member 775 rotates about the support portion 775c, and the pushing portion 775b of the first force receiving member 775 acts on the third pushed portion 770b of the second force receiving member 770. Then, the second force receiving member 770 moves to the outside of the developing unit 741 (arrow P). At this time, the upper surface part 770c of the second force receiving member 770 abuts against the second force application member 760 to prevent further movement. The position of the second force receiving member 770 at this time is called a regulation position.

However, even when the second force receiving member 770 is prevented from moving by the engagement rib 760, the force receiving device 790 including the second force application member 760 and the second force receiving member 770 is not damaged. This is because the elastic portion 775d formed by the thin portion provided on the first force receiving member 775 is bent (elastically deformed) as shown in fig. 62. Therefore, even if the movement of the second force receiving member 770 is regulated, the force receiving device 790 is not damaged.

As shown in fig. 63, when the second force application member 760 moves in the direction of the arrow E, the second force application member 760 is no longer regulated. Then, the elastic portion 775d of the first force receiving member 775 is restored from the elastically deformed position to the original position to allow the pushing portion 775b to move the second force receiving member 770b outward. Then, the second force receiving member 770b moves into the moving path of the second force application member 760.

As shown in fig. 64, the side surface 770d (second pushed portion) receives the force from the second force application member 760 by the movement of the second force application member 760 in the direction of the arrow B. Further, when the second force application member 760 is moved in the direction of arrow B, the developing unit 741 rotates about the connecting portion 746B relative to the drum unit 731, whereby the developing roller 742 is separated from the photosensitive drum 730 by a gap λ. Here, the position where the first force receiving member 775 is pushed by the first force application member 761 is fixed, and the second force receiving member 770 moves due to the movement of the second force application member 760 in the arrow B direction shown in fig. 64. Therefore, the distance I between the first force receiving member 775 and the second force receiving member 770b and the distance II between the first force receiving member 775 and the second force receiving member 770b satisfy the distance I > the distance II. In the force receiving device 790 of this embodiment, the change in distance can be regulated by the sliding of the first force application member 761 relative to the first force receiving member 775a, and the deformation of the elastic portion 775d formed by the thin portion provided on the first force receiving member 775.

The second force receiving member 770b is allowed to move by the action of the second force application member 760 by the second force application member 760 moving in the direction indicated by the arrow E in fig. 63 from the position shown in fig. 64. Similarly to the first embodiment, the developing roller 742 and the photosensitive drum 730 contact each other by the urging spring 795 provided on the cartridge 750 y.

Also in this embodiment, the structure other than the force receiving device 790 is the same as that of the cartridge 50y in the first embodiment. The operation of the first force application member 761 in this embodiment is the same as that of the first force application member 61 in the first embodiment or the first force application member 461 in the second embodiment. The force receiving device 790 of this embodiment provides advantageous effects similar to those of the first embodiment.

Seventh embodiment

Fig. 65 to 68 show a modification example of this modification example.

This embodiment will also be described with the yellow cartridge 850y containing yellow developer as an exemplary cartridge. Fig. 65 is a perspective view of the process cartridge 850y, in which the urging member 820 of the main assembly of the apparatus has been moved in the direction of arrow V (upward) shown in fig. 67, as viewed from the side of the coupling member 830a of the photosensitive drum 830. Fig. 66 is a perspective view of the process cartridge 850y as viewed from the side opposite to the coupling member 830a of the photosensitive drum 830 (the state of which is the same as that of fig. 65). Fig. 67 is a perspective view of the process cartridge 850y, in which the urging member 820 of the main assembly of the apparatus has been moved in the direction of arrow U in fig. 67, as viewed from the side of the coupling member 830a of the photosensitive drum 830. Fig. 68 is a perspective view of the process cartridge 850y as viewed from the side opposite to the coupling member 830a of the photosensitive drum 830 (the state of which is the same as that of fig. 67).

In this embodiment, as shown in fig. 65, 66, the main assembly of the apparatus includes urging members 820 for urging the cartridge 850y to the positioning portions 801a provided in the main assembly of the apparatus. The photosensitive drum 830 has a connecting member 830a for receiving a driving force, and the developing roller has a developing roller gear 869, the developing roller gear 869 is provided with a connecting member 867 for receiving the driving force, and the urging member 820 urges the cartridge 850y at a longitudinal end opposite to the other longitudinal end at which the connecting member 830a and the connecting member 867 are provided. The urging member 820 has a guide portion 820a, an urging portion 822, and an urging spring 821. The pressing portion 822 is supported by the guide portion 820a to move toward the cassette 850 y.

The urging portion 822 is urged by an urging spring 821 in the direction of an arrow U in fig. 67. The operation of the urging member 820 is similar to that of the first force application member 61 of the first embodiment; the urging member 820 moves in the direction of arrow V in fig. 67 in accordance with the opening operation of the door of the main assembly of the apparatus, and it moves in the direction of arrow U in fig. 67 in accordance with the closing operation of the door of the main assembly of the apparatus. Therefore, when the urging member 820 moves in the direction of the arrow U, the urging portion 822 comes into contact with the cartridge 850y to urge the cartridge 850y by the force of the urging spring 821. Due to this urging force, the cartridge 850y is positioned with respect to the main assembly 100 of the image forming apparatus by positioning the protrusion 831a provided on the drum frame 834 to the positioning portion 801a of the main assembly of the apparatus, similarly to the positioning operation of the cartridge 50y to the main assembly 100 of the apparatus in the first embodiment.

Also in this embodiment, as shown in fig. 65, 66, the developing unit 841 has a force receiving device 890. The force-receiving device 890 includes a first force-receiving member 875, a second force-receiving member 870, and a rod 872. In this embodiment, the drum frame 834 has a rod 872, and a hole 872a provided on the rod 872 is engaged with a shaft 834a provided on the drum frame 834, and the rod 872 is supported on the drum frame 834 rotatably about the hole 872 a. The lever 872 is urged in the direction of an arrow S in fig. 65 by the pressure of the spring 840. In other words, since the second force receiving member 870b does not receive the force from the second force application member 860, the photosensitive drum 830 and the developing roller 842 are in contact with each other.

Similar to the first embodiment, by the movement of the door (not shown) from the open position to the closed position, the urging portion 822 contacts the cartridge 850y and urges the cartridge 850y by the force of the urging spring 821, as shown in fig. 67. At this time, the contact portion 822a of the pressing portion 822 moves the contact portion 872a of the lever 872 relative to the contact portion 822a to rotate the lever 872 about the hole 872 a. As shown in fig. 67, 68, the operating portion 872b of the lever 872 moves the first force receiving member 875 in the direction of the arrow W. When the first force-receiving member 875 is moved in the direction of the arrow W, the second force-receiving member 870 is moved (protruded) from the standby position to the outside of the developing unit 841 of the cartridge 850y, similarly to the first embodiment.

The operation is the same as the first embodiment.

The process cartridge of this embodiment has the same structure as the process cartridge 50y of the first embodiment. The operation of the second force application member 860 of this embodiment is the same as that of the second force application member 60 of the first embodiment. The force receiving device 790 of this embodiment provides advantageous effects similar to those of the first embodiment.

According to the present invention, the process cartridge in which the electrophotographic photosensitive drum and the developing roller are contactable with and separable from each other, and the electrophotographic image forming apparatus in which such a process cartridge is detachably mountable can be reduced in size. Further, the force receiving portion for separating the electrophotographic photosensitive drum and the developing roller from each other is not easily damaged when the process cartridge is operated and/or when the process cartridge is transported.

Industrial applicability

As described above, according to the present invention, it is possible to provide a process cartridge (in which an electrophotographic photosensitive drum and a developing roller are contactable and separable with respect to each other) which is reduced in size, and an electrophotographic image forming apparatus (in which the process cartridge is detachably mountable) which is reduced in size.

While the invention has been described with reference to the structures disclosed herein, it is not confined to the details set forth and this application is intended to cover such modifications and changes as may be made for the purpose of improvement or within the scope of the claims.

Claims (38)

1. A process cartridge mountable to a main assembly of an image forming apparatus, the main assembly including an opening, a door movable between a closed position for closing the opening and an open position for opening the opening, a separating force applying member movable by a driving force from a driving source and for applying a separating force, and a moving force applying member applying a moving force in accordance with movement of the door from the open position to the closed position, the process cartridge comprising:

a photosensitive member unit including a photosensitive member on which an electrostatic latent image is formable;

a developing unit including a developing roller for developing the electrostatic latent image in a state where it is in contact with the photosensitive member, the developing unit being rotatably connected to the photosensitive member unit about a rotation axis so that the developing roller and the photosensitive member can be brought into contact with each other and so that the developing roller and the photosensitive member can be separated from each other;

a separation force receiving portion movable between a protruding position where the separation force receiving portion protrudes outward from the developing unit, and a standby position where the separation force receiving portion returns from the protruding position toward the rotation axis, wherein at the protruding position, the separation force receiving portion is capable of receiving a separation force from the separation force applying member and separating the developing roller from the photosensitive member, the protruding position being higher than the standby position; and

a moving force receiving portion for receiving the moving force for moving the separating force receiving portion from the moving force applying member toward the projecting position from the standby position in accordance with movement of the door from the open position to the closed position in a state where the process cartridge is mounted to the main assembly of the image forming apparatus.

2. A process cartridge according to claim 1, wherein said separating force receiving portion is in said standby position in a case where said moving force receiving portion does not receive the moving force from said moving force applying member.

3. A process cartridge according to claim 2, further comprising a spring for urging said separating force receiving portion from said projecting position to said standby position.

4. A process cartridge according to claim 3, wherein said separation force receiving portion is movable away from said rotational axis against a force from said spring under a moving force received by said moving force receiving portion from said moving force applying member.

5. A process cartridge according to claim 1, further comprising a separating force receiving member rotatably supported by said developing unit, wherein said separating force receiving member is provided at an end portion thereof with said separating force receiving portion, said separating force receiving portion being movable in accordance with rotation of said separating force receiving member.

6. A process cartridge according to claim 1, further comprising a separating force receiving member slidably supported by said developing unit, wherein said separating force receiving member is provided at an end portion thereof with said separating force receiving portion, said separating force receiving portion being movable in accordance with sliding of said separating force receiving member.

7. A process cartridge according to claim 1, further comprising an elastic portion capable of being elastically deformed in a case where said separating force receiving portion receives the separating force to be applied to said developing unit in a state where said moving force receiving portion receives said moving force from said moving force applying member for moving said separating force receiving portion from said standby position toward said projecting position.

8. A process cartridge according to claim 7, further comprising a moving force receiving member provided with said moving force receiving portion and a separating force receiving member provided with said separating force receiving portion, wherein said elastic portion is provided between said separating force receiving member and said moving force receiving member.

9. A process cartridge according to claim 7, further comprising a moving force receiving member provided with said moving force receiving portion and said elastic portion.

10. A process cartridge according to claim 1, wherein said moving force receiving portion and said separating force receiving portion are integral with each other.

11. An image forming apparatus comprising:

a process cartridge mountable to a main assembly of the image forming apparatus, the process cartridge including a photosensitive member for carrying an electrostatic latent image, a developing roller contactable to the photosensitive member to develop the electrostatic latent image, and a separating force receiving portion for receiving a separating force for separating the developing roller from the photosensitive member; and

a main assembly, the main assembly comprising:

an opening;

a door movable between a closed position for closing the opening and an open position for opening the opening to allow the process cartridge to be mounted;

a protrusion force applying member for applying a protrusion force for protruding the separation force receiving portion from a standby position to a protrusion position higher than the standby position in accordance with a closing operation of the door;

a separating force applying member movable between a separating force applying position, at which a separating force is applied to said separating force receiving portion at said projecting position, and a retracted position, retracted from said separating force applying position, wherein said separating force applying member is at said separating force applying position when said process cartridge is to be mounted to said main assembly in a state in which said door is opened;

a driving member for driving the separating force applying member, wherein after the process cartridge is mounted to the main assembly and before an image forming operation of the image forming apparatus, the driving member drives the separating force applying member to retract the separating force applying member to the retracted position and then restores the separating force applying member to the separating force applying position after the door is closed;

wherein a contact portion is provided in the process cartridge and is contactable to the separating force applying member to prevent the separating force receiving portion from protruding to the protruding position when the protruding force applying member applies the protruding force in accordance with the closing operation of the door in a state where the separating force applying member is at the separating force applying position;

wherein an elastic portion is provided in the process cartridge, the elastic portion being capable of being elastically deformed so that the separating force receiving portion does not protrude to the protruding position in a state where the protruding force applying member applies the protruding force;

wherein after the process cartridge is mounted to the main assembly and the door is closed, the separating force receiving portion is projected to the projecting position by a restoring force of the elastic portion as the separating force applying member is retracted to the retracted position, and receives a separating force as the separating force applying member is restored to the separating force applying position in a state where the separating force receiving portion is in the projecting position.

12. An image forming apparatus according to claim 11, wherein said process cartridge includes a separating force receiving member provided with said separating force receiving portion.

13. An image forming apparatus according to claim 12, wherein said process cartridge movably supports said separating force receiving member, and said separating force receiving portion is projected to the projected position with the movement of said separating force receiving member.

14. An image forming apparatus according to claim 13, wherein said process cartridge rotatably supports said separating force receiving member, said separating force receiving portion being projected to the projected position with rotation of said separating force receiving member.

15. An image forming apparatus according to claim 13, wherein said process cartridge slidably supports said separating force receiving member, said separating force receiving portion being projected to the projected position with the sliding of said separating force receiving member.

16. The image forming apparatus according to any one of claims 13 to 15, wherein said separating force receiving member is provided with said contact portion.

17. An image forming apparatus according to claim 16, wherein in a state in which said separating force receiving portion is in the projecting position, said separating force receiving portion enters a moving path between the retracted position and the separating force applying position of said separating force applying member.

18. An image forming apparatus according to claim 17, wherein said separating force receiving portion is out of said movement path in a state where said contact portion contacts the separating force applying member.

19. An image forming apparatus according to claim 12, wherein said process cartridge is provided with a projecting force receiving member for receiving the projecting force from said projecting force applying member.

20. An image forming apparatus according to claim 19, wherein said protruding force receiving member includes said elastic portion.

21. An image forming apparatus according to claim 19, wherein said elastic portion is disposed between said projecting force receiving member and said separating force receiving member.

22. An image forming apparatus according to claim 18, wherein said process cartridge includes a projecting force receiving member for receiving the projecting force from said projecting force applying member.

23. An image forming apparatus according to claim 22, wherein said protruding force receiving member is provided with said elastic portion.

24. An image forming apparatus according to claim 22, wherein said elastic portion is disposed between said projecting force receiving member and said separating force receiving member.

25. A process cartridge mountable to a main assembly of an image forming apparatus, comprising:

a photosensitive member configured and positioned to carry an electrostatic latent image;

a developing roller capable of contacting the photosensitive member to develop the electrostatic latent image;

a separation force receiving portion configured and positioned to receive a separation force for separating the developing roller from the photosensitive member;

the main assembly of the image forming apparatus includes: an opening; a door movable between a closed position for closing the opening and an open position for opening the opening; a protrusion force applying member for applying a protrusion force for protruding the separation force receiving portion from a standby position to a protrusion position higher than the standby position in accordance with a closing operation of the door; a separating force applying member movable between a separating force applying position at which said separating force is applicable to said separating force receiving portion at said projecting position, and a retracted position retracted from said separating force applying position, said separating force applying member being at said separating force applying position when said process cartridge is mounted to the main assembly of the image forming apparatus in a state in which said door is opened; and a driving member for driving the separating force applying member, wherein after the process cartridge is mounted to the main assembly of the image forming apparatus and the door is closed and before an image forming operation of the image forming apparatus, the driving member drives the separating force applying member to retract the separating force applying member to the retracted position and then restores the separating force applying member to the separating force applying position,

the process cartridge further includes:

a contact portion contactable to the separating force applying member to prevent the separating force receiving portion from protruding to the protruding position when the protruding force applying member applies the protruding force in accordance with the closing operation of the door in a state in which the separating force applying member is at the separating force applying position; and

an elastic portion capable of being elastically deformed so that the separation force receiving portion does not protrude to the protruding position in a state where the protruding force applying member applies the protruding force;

wherein, after the door is closed, as the separating force applying member is retracted to the retracted position, the separating force receiving portion is projected to the projected position by a restoring force of the elastic portion, and, in a state where the separating force receiving portion is in the projected position, as the separating force applying member is restored to the separating force applying position, the separating force receiving portion is caused to receive the separating force.

26. A process cartridge according to claim 25, further comprising a separating force receiving member provided with said separating force receiving portion.

27. A process cartridge according to claim 26, wherein said process cartridge movably supports said separating force receiving member, and said separating force receiving portion is projected to said projected position in accordance with the movement of said separating force receiving member.

28. A process cartridge according to claim 27, wherein said process cartridge rotatably supports said separating force receiving member, said separating force receiving portion being projected to said projecting position with rotation of said separating force receiving member.

29. A process cartridge according to claim 27, wherein said process cartridge supports said separating force receiving member in a slidable manner, and said separating force receiving portion is projected to said projected position with the sliding of said separating force receiving member.

30. A process cartridge according to any one of claims 27-29, wherein said separating force receiving member is provided with said contact portion.

31. A process cartridge according to claim 30, wherein in a state in which said separating force receiving portion is in said projected position, said separating force receiving portion enters a moving path between said retracted position and said separating force applying position of said separating force applying member.

32. A process cartridge according to claim 31, wherein said separating force receiving portion is out of said moving path in a state where said contact portion contacts the separating force applying member.

33. A process cartridge according to claim 26, further comprising a projection force receiving member constructed and positioned for receiving the projection force from said projection force applying member.

34. A process cartridge according to claim 33, wherein said protrusion force receiving member is provided with said elastic portion.

35. A process cartridge according to claim 33, wherein said elastic portion is disposed between said projecting force receiving member and said separating force receiving member.

36. A process cartridge according to claim 32, further comprising a projection force receiving member constructed and positioned to receive the projection force from said projection force applying member.

37. A process cartridge according to claim 36, wherein said projecting force receiving member is provided with said elastic portion.

38. A process cartridge according to claim 36, wherein said elastic portion is disposed between said projecting force receiving member and said separating force receiving member.