JP5288769B2 - Image forming apparatus - Google Patents

Description

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

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

  In some process cartridges, at least the developing means and the electrophotographic photosensitive drum are integrally formed into a cartridge that can be attached to and detached from the main body of the electrophotographic image forming apparatus.

  As an image forming apparatus using a conventional process cartridge, there is an in-line type color electrophotographic image forming apparatus in which a plurality of process cartridges 7 are arranged in a line. As a developing means for such a cartridge, a contact developing method is known in which development is performed in a state where the developing roller and the photosensitive drum are in contact with each other. In this system, the developing roller is urged against the photosensitive drum in order to hold the developing roller and the photosensitive drum during image formation under a predetermined contact pressure.

  In general, since the developing roller used in the contact developing method has an elastic layer, the portion of the elastic layer that contacts the photosensitive drum is deformed when the cartridge is not used for a long time with the cartridge mounted on the apparatus main body. There is a case. This may cause uneven density on the recorded image. In order to prevent this, it was necessary to select materials for the developing roller and strictly manage manufacturing conditions, which was a production load.

  Accordingly, there has been proposed a process cartridge and an image forming apparatus provided with a mechanism for separating the photosensitive drum and the developing roller when the image forming operation is not performed (for example, see Patent Document 1).

  There has also been proposed a process cartridge and an image forming apparatus configured to separate a developing roller using a separating member when the process cartridge is not used (see, for example, Patent Document 2).

  Also, a separation member is provided for holding the separation state of the developing roller at the time of shipment of the process cartridge, and the main body abutting portion and the separation member are abutted and released by the mounting operation to the image forming apparatus. There is a thing with the composition which has.

Japanese Patent Laid-Open No. 2001-337511 (page 5-6, FIG. 2) JP 2002-6722 A

  In the above prior art, when the process cartridge is attached to the image forming apparatus, the separation member first comes into contact with the main body contact portion to release the separation state. For this reason, the developing unit once moved from the separated position to the contact position during the mounting, and the developing roller was in contact with the photosensitive drum. Since the developing unit is urged by the urging member, the impact of the developing roller coming into contact with the photosensitive drum is transmitted to the user's hand at the time of mounting, so that the operational feeling is not smooth.

  Then, the process cartridge is mounted further in the back and is completely mounted in the image forming apparatus main body. At this time, it is necessary to place the developing unit in a separated state by causing the force receiving portion of the developing unit to ride on the action member of the apparatus main body.

  For this reason, two types of loads, that is, release of the separation member and riding on the action member of the force receiving portion have occurred as loads that are applied when the process cartridge is mounted.

  The present invention is a further development of the above-described conventional technique, and an object thereof is to improve user operability when the process cartridge is mounted on the main body of the image forming apparatus.

Typical configuration of an image forming apparatus according to the present invention in order to solve the above described problems is the imageable electrophotographic image forming apparatus on a recording medium, and sensitive optical body, and can be separable before Symbol feeling light body a developing roller, said process cartridge so as to separated from the front Symbol sensitive optical member wherein the developing roller and a force receiving portion for receiving a force to separate the a process cartridge having, an the previous SL sensitive optical body the developing roller together is attached to a predetermined position of, and spacing member retractable from said predetermined position so as to abut the front Symbol sensitive optical member and said developing roller, a pre-SL of a process cartridge mountable mounting portion, prior Symbol process cartridge and the abutment member for retracting said spacer member and the contact with the spacer member before mounting process is completed to the mounting portion from said predetermined position, and a pre-Symbol developing roller and the front Symbol feeling light body away A first position for urging the force to the force receiving portion to cause, and a second position retracted from the first position so as to abut a front Symbol developing roller and the front Symbol feeling light body And a force applying member that maintains the first position at any point in the mounting process, and the separation member is attached to the predetermined position. When the mounting process is started, the separation member is retracted from the predetermined position, and the force applying member positioned at the first position is in contact with the force receiving portion. The mounting process is configured to be completed, and the photosensitive member and the developing roller are configured not to contact each other at any point in the mounting process .

  According to the present invention, it is possible to improve user operability when the process cartridge is mounted on the image forming apparatus main body.

[First embodiment]
A process cartridge and an image forming apparatus according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an overall configuration diagram of an image forming apparatus according to the present embodiment.

(Overall configuration of image forming apparatus)
First, the overall configuration of the image forming apparatus will be described. The image forming apparatus main body 100 shown in FIG. 1 has four process cartridge mounting portions (not shown). FIG. 5 is a perspective view showing attachment of the process cartridge 7 to the apparatus main body 100.

  As shown in FIG. 5, the process cartridge 7 (7a-7d) can be attached to and detached from the mounting portion 90 of the apparatus main body 100, the front cover 8 provided on the apparatus main body 100 is opened, and the mounting direction (arrow E direction). Each is mounted along. That is, the cartridge 7 is configured to be detachable from the mounting portion 90. The cartridge 7 includes a photosensitive unit 26 (26a-26d) and a developing unit (second unit) 4 (4a-4d). The developing unit 4 has a developing roller 40. The photoreceptor unit 6 includes a charging roller 2 (2a-2d), a cleaning member 6 (6a-6d), and a photoreceptor drum 1 (1a-1d) as an electrophotographic photoreceptor.

  When forming an image, each photosensitive drum 1 is rotated, and the scanner unit 3 selectively exposes the photosensitive drum 1 uniformly charged by the charging roller 2. As a result, an electrostatic latent image is formed on the photosensitive drum 1. The formed electrostatic latent image is developed by a developing roller 40 as a developing member, and each color developer image (toner image) is formed on each photoconductive drum 1.

  On the other hand, the recording sheet S stored in the cassette 17 at the lower part of the apparatus main body is conveyed to the nip portion between the transfer belt 11 and the secondary transfer roller 15 by the feeding roller 18 and the conveying roller 19, and the color image on the transfer belt 11. Is transcribed.

  The recording sheet S to which the toner image is transferred is heated and pressed by the fixing unit 20 to fix the toner image. Thereafter, the recording sheet S is discharged out of the apparatus by the discharge roller 23.

(Process cartridge 7)
Next, the process cartridge 7 will be described. FIG. 2 is a longitudinal sectional view of the cartridge 7 containing the developer (toner). In the present embodiment, the cartridges 7a-7d have the same configuration. The cartridges 7a to 7d store yellow, magenta, cyan, and black toners.

  As shown in FIG. 2, the cartridge 7 (7a-7d) is configured by integrally forming a photosensitive unit (first unit) 26 (26a-26d) and a developing unit 4 (4a-4d) into a cartridge. The

  The photosensitive unit 26 includes a photosensitive drum 1 (1a-1d), a charging roller 2 (2a-2d), a cleaning member 6 (6a-6d), and a cleaning frame 27. The photosensitive drum 1 is rotatably attached to the cleaning frame 27. A charging roller 2 and a cleaning member 6 are disposed on the circumference of the photosensitive drum 1. The residual toner removed from the surface of the photosensitive drum 1 by the cleaning member 6 falls into the removed toner chamber 27a. The charging roller 2 is pressurized toward the photosensitive drum 1.

  The developing unit 4 includes a developing roller 40 that rotates in the direction of arrow B in contact with the photosensitive drum 1. The developing unit 4 is supported so as to be movable (rotatable) with respect to the photosensitive unit 26 with a shaft 37 as a rotation center.

  The developing unit 4 is movable to a position where the photosensitive drum 1 and the developing roller 40 are in contact with each other and a position where the photosensitive drum 1 and the developing roller 40 are separated from each other. The developing unit 4 is biased by a pressure spring 53 that is a biasing member so as to move (rotate) to a position where the photosensitive drum 1 and the developing roller 40 come into contact with each other. When the image is formed on the cartridge 7, the developing unit 4 is biased by the pressure spring 53, so that the developing unit 4 rotates around the shaft 37 and the developing roller 40 contacts the photosensitive drum 1.

(Separation mechanism between the photosensitive drum 1 and the developing roller 40 in the apparatus main body of the process cartridge 7)
Next, the separation mechanism of the developing roller 40 when the cartridge 7 is mounted on the mounting portion 90 will be described. FIG. 3 is a view showing a state in which the developing roller 40 is in contact with the photosensitive drum 1 when the cartridge 7 is mounted on the mounting portion 90. FIG. 4 is a view showing a state in which the developing roller 40 is separated from the photosensitive drum 1.

  The apparatus main body 100 has a separation cam 111 as an action member at the center in the longitudinal direction of the cartridge 7. The separation cam 111 is a separation means for separating the developing roller 40 from the photosensitive drum 1 against the pressing force of the pressure spring 53. The separation cam 111 is fixedly supported on the rotation shaft 80 and rotates by the rotation of the rotation shaft 80. The separation cam 111 has two surfaces, a small-diameter portion 111b having a small radius and a large-diameter portion 111c having a large radius.

  The radius of the small diameter portion 111b is large enough to have a clearance T with the force receiving portion 4e provided in the developing unit 4 as shown in FIG. 3 in a state where the developing roller 40 is in contact with the photosensitive drum 1. It has become. The radius of the large-diameter portion 111c is in contact with the force receiving portion 4e and rotates the developing unit 4, so that the developing roller 40 is separated from the photosensitive drum 1 by a gap L1 as shown in FIG. Position).

  When the apparatus main body 100 is stopped, as shown in FIG. 4, the large-diameter portion 111c of the separation cam 111 abuts against the force receiving portion 4e (this position of the separation cam 111 is referred to as a first position). At this time, the force receiving portion 4e is pushed by the large-diameter portion 111c, the developing unit 4 rotates about the shaft 37, and the developing roller 40 is held in a state separated from the photosensitive drum 1 by the gap L1. Accordingly, even if the cartridge 7 is not used for a long time when the cartridge 7 is mounted on the mounting portion 90, the elastic layer of the developing roller 40 is not deformed, so that density unevenness or the like is not caused on the recorded image.

  Next, when an image forming operation is started by a print signal, the separation cam 111 moves (rotates) to a position (position shown in FIG. 3) where the small diameter portion 111b faces the force receiving portion 4b in accordance with the development operation timing. (This position of the separation cam 111 is referred to as a second position). In this state, the force receiving portion 4e is separated from the small-diameter portion 111b by a gap T, and the developing roller 40 contacts the photosensitive drum 1 with a predetermined pressure by the elastic force of the pressure spring 53. As a result, an image can be formed.

(Separation members 50 and 51 of the process cartridge 7)
Next, the separation state holding and release mechanism of the separation members 50 and 51 of the process cartridge 7 will be described.

  FIG. 6 is a perspective view showing attachment of the process cartridge 7 to the apparatus main body 100. 7 and 10 are external perspective views as seen from the downstream side and the upstream side of the cartridge 7 in the mounting direction.

  The cartridge 7 has a separation member 50 (see FIG. 7) on the downstream side (back side) in the mounting direction (arrow E direction in FIG. 5), and the separation member 51 (see FIG. 10) on the upstream side (front side) in the mounting direction. have. That is, the separation members 50 and 51 are disposed at both ends in the longitudinal direction of the process cartridge 7. As shown in FIG. 6, the apparatus main body 100 includes main body contact portions 57 and 58 as contact members for releasing the separation.

(Separation holding and releasing structure of the separation member 50)
First, the separation holding and releasing configuration of the separation member 50 will be described. FIG. 8 is a perspective view showing a state in which the separating member 50 is supported on the developing unit 4. FIG. 9 is a cross-sectional view of the engaging portion of the separation member 50 to the photosensitive unit 26. FIG. 9A shows the engaged state of the separating member 50, and FIG. 9B shows the released state. In order to show the inside of the cover member 62 that covers the separation member 50, the cover member 62 is indicated by a dotted line.

  As shown in FIGS. 7 to 9, the separation member 50 is supported by the support portion 4f of the developing unit 4 so as to be rotatable about the shaft 50a, and the cover member 62 prevents the separation member 50 from coming off from the support portion 4f. The

  In the engaged state shown in FIG. 9A, the engaging portion 50b of the separating member 50 is engaged with the engaging hole 26e of the photoreceptor unit 26 (here, the position of the separating member 50 is set to the separating position). Called). As a result, the developing unit 4 is positioned at a second separated position where the photosensitive drum 1 and the developing roller 40 are separated.

  The mounting operation of the cartridge 7 is performed from this engaged state, and the engaged state of the separating member 50 is released as shown in FIG. 9B.

  When the cartridge 7 is inserted into the mounting portion 90 in a state where the spacing member 50 is located at the spacing position, the insertion operation (the movement of the cartridge 7 in the mounting direction (direction of arrow E)) causes the insertion of the spacing member 50. The contact portion 50 c contacts the main body contact portion 57. As a result, the separating member 50 rotates about the shaft 50a in the direction of arrow F and retracts from the engaging hole 26e. That is, the separation member 50 retreats from the separation position by contacting the main body contact portion 57. As a result, the engagement between the engaging portion 50b and the engaging hole 26e is released, the separated state of the developing unit 4 is released, and the developing roller 40 and the photosensitive drum 1 come into contact with each other. In other words, the separating members 50 and 51 are retracted from the separating position and moved to the retracting position.

  The developing unit 4 released from the separated state is rotated to the contact position by the urging force of the pressure spring 53.

(Separation holding and releasing structure of the separation member 51)
Next, the separation holding and releasing configuration of the separation member 51 will be described.

  FIG. 10 is an external perspective view of the cartridge 7 as viewed from the upstream side in the mounting direction. The separation member 51 is supported so as to be rotatable about the shaft 26 f of the photosensitive unit 26, and the cover member 63 prevents the separation from the shaft 26 f.

  FIG. 11 is a perspective view showing an engagement state of the separating member 51 with the developing unit 4. FIG. 11 is drawn with the photoreceptor unit 26 omitted. As shown in FIG. 11, when the separated state is maintained, the restricting portion 51a of the separating member 51 is hung on the flange-shaped portion 4i on the developing unit 4 side.

  FIG. 12 is a side view of the separating member 51 as viewed from the cover member 63 side. FIG. 12 is drawn with the cover member 63 omitted to show the spacing member 51 inside the cover member 63. FIGS. 12A and 12B show the separated holding state by the separating member 51 and the separated release state.

  In the engaged state shown in FIG. 12A, the restricting portion 51 a of the separating member 51 and the flange portion 4 i of the developing unit 4 protruding through the hole 27 b of the cleaning frame 27 and the wall surface 26 g of the photosensitive unit 26. It is sandwiched between. As a result, the developing unit 4 is positioned at a second separated position where the photosensitive drum 1 and the developing roller 40 are separated.

  Then, as shown in FIG. 12B, when the cartridge 7 is mounted in the apparatus main body, the contact portion 51 b of the separation member 51 is moved to the main body of the apparatus main body 100 by the operation of mounting the cartridge 7 in the mounting portion 90. It abuts against the abutment portion 58. As a result, the restricting portion 51a of the separating member 51 rotates in the direction of arrow G about the shaft 26f, and the restricting portion 51a is retracted from the hook-shaped portion 4i. As a result, the hook-shaped portion 4i is no longer supported and the separated state of the developing unit 4 is released.

  The developing unit 4 released from the separated state is rotated to the contact position by the urging force of the pressure spring 53.

(Mounting of the process cartridge 7 to the image forming apparatus main body 100 (mounting unit 90))
Next, the mounting operation of the process cartridge 7 will be described.

  FIG. 13 is a front view showing the middle of mounting the cartridge 7 on the mounting portion 90. In the state shown in FIG. 13, the mounting of the cartridge 7 is not completed, and the separation members 50 and 51 are not disengaged. Therefore, the separation amount (distance) L2 between the developing roller 40 and the photosensitive drum 1 is due to the separation members 50 and 51. The separation amount L2 is in a relationship of L1 <L2 with the separation amount L1 by the separation cam 111. For this reason, when the cartridge 7 is mounted, a gap T2 is left between the force receiving portion 4e of the developing unit 4 and the large diameter portion 111c of the separation cam 111.

  FIG. 14 is a cross-sectional view of the cartridge 7 as viewed from the developing unit side, showing the middle of mounting the cartridge 7 on the mounting portion 90. FIG. 15 is a cross-sectional view seen from the developing unit side showing a state in which the cartridge 7 is completely attached to the apparatus main body 100.

  First, when the cartridge 7 is mounted on the mounting portion 90 and reaches the position shown in FIG. 14, the force receiving portion 4e of the developing unit 4 overlaps the separation cam 111 (shaded portion R in FIG. 14). As described above, there is a gap T2 between the contact surfaces of the force receiving portion 4e and the separation cam 111 (large diameter portion 111c). Do not raise.

  After that, when the cartridge 7 is further attached and comes to the position shown in FIG. 15, the separating members 50 and 51 come into contact with the main body contact portions 57 and 58, respectively. Thereby, the engagement state of the separation members 50 and 51 is released as described above. In a state in which the engagement of the separation members 50 and 51 is released, the contact surfaces of the force receiving portion 4e and the separation cam 111 (large-diameter portion 111c) are in positions facing each other and are not in contact (gap T2). In a vacant position). In other words, the engagement of the separation members 50 and 51 is seen in the orthogonal direction (the direction of contact / separation of the force receiving portion 4e (the direction of the arrow M in FIG. 13)) orthogonal to the mounting direction (the direction of the arrow E). Before the release, at least a part of the force receiving portion 4e and at least a part of the separation cam 111 overlap. In other words, the large diameter portion 111c and the force receiving portion 4e are not in contact with each other in a state where the cartridge 7 is inserted into the mounting portion 90 to a position where the large diameter portion 111c and the force receiving portion 4e can contact each other. Opposite. Here, the contact / separation direction of the force receiving portion 4e is a moving direction of the force receiving portion 4e when the developing unit 4 contacts / separates with respect to the photosensitive unit 26. Further, after the cartridge 7 is inserted into the mounting portion 90 to a position where the large diameter portion 111c and the force receiving portion 4e can come into contact with each other, the main body contact portion 57 comes into contact with the separation members 50 and 51 to separate the separation member 50. , 51 are retracted from the separated position.

  As a result, the force receiving portion 4e of the developing unit 4 contacts the large diameter portion 111c of the separation cam 111 at the shaded portion H in FIG. As a result, the separated state of the developing unit 4 in the apparatus main body 100 is maintained. That is, after the main body abutting portions 57 and 58 are brought into contact with the separating members 50 and 51 to retract the separating members 50 and 51 from the separated position, the developing roller 40 and the photosensitive drum 1 are not brought into contact with each other. The diameter part 111c and the force receiving part 4e abut.

  As described above, during the mounting operation of the cartridge 7, the developing roller 40 and the photosensitive drum 1 are not brought into contact with each other, so that the impact due to the contact is not transmitted to the user's hand and the operational feeling can be improved. Further, as the mounting force during the mounting operation, the contact force between the force receiving portion 4e and the separation cam 111 is not generated, but only the load due to the disengagement of the separation members 50 and 51 is used, thereby reducing the mounting force. can do.

[Second Embodiment]
Next, a second embodiment of the process cartridge and the image forming apparatus according to the present invention will be described with reference to the drawings. FIG. 16 is a front view when the cartridge is mounted on the main body of the image forming apparatus. FIG. 17 is a perspective view of the process cartridge mounting opening of the image forming apparatus main body. About the part which overlaps with said 1st embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  As shown in FIGS. 16 and 17, the process cartridge and the image forming apparatus of the present embodiment are provided with an inclined portion 61 in front of the mounting direction of the separation cam 111 of the process cartridge and the image forming apparatus of the first embodiment. It is.

  The inclined portion 61 contacts the force receiving portion 4e and presses the force receiving portion 4e by the operation of mounting the process cartridge 7 in the mounting direction (arrow E direction), and moves the developing unit 4 to the second separated position. The back side in the mounting direction of the inclined portion 61 is formed high. The inclined portion 61 pushes the force receiving portion 4e to the same extent or more than the amount by which the large diameter portion 111c pushes the force receiving portion 4e.

  In the state shown in FIG. 16, the mounting is not yet completed, and the separation members 50 and 51 are not disengaged. Therefore, the separation amount L3 between the developing roller 40 and the photosensitive drum 1 shown here is due to the separation members 50 and 51. The separation amount L3 is in a relationship of L1> L3 with the separation amount L1 by the separation cam 111. For this reason, the force receiving portion 4e and the large-diameter portion 111c overlap each other at the shaded portion K in FIG. Therefore, when the mounting is completed, it is necessary to ride the force receiving portion 4e of the developing unit 4 on the separating cam 111 by the shaded portion.

  However, as shown in FIG. 17, by providing the inclined portion 61 in front of the separation cam 111 in the mounting direction of the cartridge 7, the force receiving portion 4 e first rides on the inclined portion 61 and is attached to the separation cam 111. Ride smoothly.

  In the present embodiment, the inclined portion 61 is provided in the apparatus main body 100, but may be provided in the cartridge 7. In this case, it is necessary to provide the inclined portion 61 on the back side of the force receiving portion 4e in the mounting direction.

  Hereinafter, the mounting operation of the process cartridge 7 will be described.

(Installation of process cartridge)
18 to 20 are cross-sectional views seen from the developing unit side for explaining the mounting of the cartridge 7 to the mounting portion 90. First, when the cartridge 7 is mounted on the mounting portion 90 in the mounting direction (arrow E direction) and comes to the position shown in FIG. 18, the force receiving portion 4 e is mounted along the inclined portion 61 and moves to the separation cam 111. Delivered.

  After that, when the cartridge 7 is further mounted and reaches the position shown in FIG. 19, the force receiving portion 4e is separated from the inclined portion 61 and abuts only on the separation cam 111 (large diameter portion 111c) at the shaded portion H. . After that, when the cartridge 7 is further mounted and mounted to the position shown in FIG. 20, the separating members 50 and 51 come into contact with the main body contact portions 57 and 58, respectively, and the engaged state of the separating members 50 and 51 is Release (separation members 50 and 51 retract from the separation position). That is, the contact surfaces of the force receiving portion 4e and the separation cam 111 (large-diameter portion 111c) are in an opposing position and a contact position in a state where the engagement of the separation members 50 and 51 is released. In other words, before the engagement of the separation members 50 and 51 is released as viewed along the orthogonal direction (direction of the force receiving portion 4e (arrow M direction)) orthogonal to the mounting direction (arrow E direction). Further, at least a part of the force receiving portion 4e overlaps with at least a part of the separation cam 111. Here, the contact direction of the force receiving portion 4e is that the developing unit 4 is in contact with the photosensitive unit 26. This is the direction of movement of the force receiving portion 4e at the time of separation As described above, the impact due to contact is prevented by not contacting the developing roller 40 and the photosensitive drum 1 during the mounting operation of the process cartridge 7. Is not transmitted to the user's hand, and the operational feeling can be improved.

  In the present embodiment, as the mounting force during the mounting operation, a load that the force receiving portion 4e rides on the inclined portion 61 is generated. However, the inclined portion 61 is provided long in the mounting direction of the process cartridge 7, and the inclined portion 61 gradually pushes the force receiving portion 4e. Thereby, the mounting load can be gradually changed.

  Further, in the present embodiment, the developing unit 4 is further separated by the separation cam 111 of the apparatus main body 100 than the development unit 4 is separated by the separation members 50 and 51. For this reason, as a result, the load for maintaining the separation in the engaging portions of the separation members 50 and 51 is eliminated. Accordingly, it is possible to eliminate the load caused by the disengagement of the separation members 50 and 51 when the cartridge 7 is completely mounted.

[Third embodiment]
Next, a process cartridge and an image forming apparatus according to a third embodiment of the invention will be described with reference to the drawings. About the part which overlaps with said 1st embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  As shown in FIGS. 21 to 24, the process cartridge and the image forming apparatus of the present embodiment are replaced with a protective cover (protective member) that is a separation member in place of the separation member 51 of the process cartridge and the image forming apparatus of the first embodiment. ) 60 is provided.

  That is, the separation member 50 is used at one end of the cartridge 7 (one end on the downstream side in the mounting direction), and the protective cover 60 of the photosensitive drum 1 is used at the other end (one end on the upstream side in the mounting direction). The protective cover 60 for the photosensitive drum 1 will be described below.

(Protective cover 60)
The protective cover 60 is provided separately from the cartridge 7 and is attached to the cartridge 7 to protect the photosensitive drum 1. The configuration of the protective cover 60 of the photosensitive drum 1 will be described.

  FIG. 21 is an external perspective view showing a state where the protective cover 60 is attached to the cartridge 7. As shown in FIG. 21, the protective cover 60 has slide ribs 60a and 60b and a separation holding portion 60c.

  The protective cover 60 is slidably supported in the longitudinal direction of the cartridge 7 by engaging the slide ribs 60 a and 60 b with the slide grooves 26 h and 26 i formed in the photoconductor unit 26.

  The separation holding part 60c is provided so as to hang down from the protective cover 60 on the upstream side in the mounting direction. On the upstream side in the mounting direction, the separation holding portion 60c is sandwiched between the contact portion 4h of the development unit 4 and the contact portion 26k of the photosensitive unit 26, thereby holding the development unit 4 in the second separation position. To do.

  On the other hand, on the downstream side in the mounting direction, a separation member 50 is attached, and the separation state of the developing unit 4 is maintained.

(Installation of process cartridge)
FIG. 22 is a perspective view showing the middle of mounting the cartridge 7 on the mounting portion 90. FIG. 23 is a cross-sectional view of the cartridge 7 as viewed from the developing unit side showing the middle of mounting the cartridge 7 on the mounting portion 90. FIG. 24 is a cross-sectional view seen from the developing unit side showing a state in which the cartridge 7 is completely attached to the attachment portion 90.

  As shown in FIGS. 22 and 23, when the cartridge 7 is mounted, the protective cover 60 is positioned on the engaging portion 100b of the apparatus main body 100 while holding the handle 60d of the protective cover 60. The protective cover 60 is attached to the apparatus main body 100 while the cartridge 7 is slid with respect to the protective cover 60 with the protective cover 60 as it is.

  As shown in FIG. 23, when the cartridge 7 is slid from the protective cover 60 and mounted in the apparatus main body, the separation holding portion 60c is moved between the contact portion 4h of the developing unit 4 and the contact portion 26k of the cleaning unit 126. Deviate from. Thereby, first, the engagement of the developing unit 4 on the upstream side in the mounting direction is released.

  After the engagement of the developing unit 4 is released, the protective cover 60 is detached from the cartridge 7 by sliding the cartridge 7 as it is.

  At this time, since the engagement state of the separation member 50 on the upstream side in the mounting direction has not yet been released, the development unit 4 is kept in the separation state on the upstream side in the mounting direction. Next, when the cartridge 7 is mounted to the position shown in FIG. 24, the separating member 50 comes into contact with the main body contact portion 57, and the engaged state of the separating member 50 is released.

  Note that the disengagement of the separation member 50 is performed immediately before the completion of the mounting of the process cartridge 7. Therefore, the contact state between the force receiving portion 4e of the developing unit 4 and the separation cam 111 before and after the disengagement of the separation member 50 can be taken in both cases of the first and second embodiments. That is, when the force receiving portion 4e and the separation cam 111 abut after the engagement state is released as in the first embodiment, and when the force receiving portion 4e is released before the engagement state is released as in the second embodiment. Either of the cases where the separation cam 111 is already in contact can be taken.

  Therefore, regarding the relationship between the force receiving portion 4e and the separation cam 111, it is possible to obtain the same action as in the first and second embodiments, and the mounting force can be reduced.

1 is an overall configuration diagram of an image forming apparatus according to a first embodiment. It is a longitudinal cross-sectional view of a process cartridge. FIG. 4 is a diagram illustrating a state in which a developing roller is in contact with a photosensitive drum. FIG. 6 is a diagram illustrating a state where the developing roller is separated from the photosensitive drum. FIG. 4 is a perspective view showing mounting of a process cartridge to the image forming apparatus main body. FIG. 4 is a perspective view showing mounting of a process cartridge to the image forming apparatus main body. FIG. 6 is an external perspective view as viewed from the downstream side in the mounting direction of the process cartridge. FIG. 6 is a perspective view of a separation member on the downstream side in the mounting direction of the process cartridge. (A) It is a figure which shows the engagement state of the separation member of the mounting direction downstream. (B) It is a figure which shows the cancellation | release state of the separation member of the mounting direction downstream. FIG. 6 is an external perspective view as viewed from the upstream side in the mounting direction of the process cartridge. FIG. 6 is a perspective view of a separation member on the upstream side in the mounting direction of the process cartridge. (A) It is a figure which shows the engagement state of the separation member of the mounting direction upstream. (B) It is a figure which shows the cancellation | release state of the separation member of the mounting direction upstream. FIG. 4 is a front view illustrating a process in the process of mounting the process cartridge on the image forming apparatus main body. FIG. 4 is a cross-sectional view showing a process cartridge being attached to the image forming apparatus main body. FIG. 3 is a cross-sectional view illustrating a state where a process cartridge is completely attached to the image forming apparatus main body. FIG. 10 is a front view illustrating a process in the middle of mounting a process cartridge according to a second embodiment on an image forming apparatus main body. FIG. 10 is a perspective view of a process cartridge mounting opening of an image forming apparatus main body according to a second embodiment. FIG. 10 is a cross-sectional view illustrating a process in the middle of mounting a process cartridge according to a second embodiment on an image forming apparatus main body. FIG. 10 is a cross-sectional view illustrating a process in the middle of mounting a process cartridge according to a second embodiment on an image forming apparatus main body. FIG. 10 is a cross-sectional view illustrating a state where the process cartridge according to the second embodiment is completely attached to the image forming apparatus main body. It is an external appearance perspective view of a process cartridge and a protective cover according to a third embodiment. FIG. 9 is a perspective view illustrating a process in the middle of mounting a process cartridge according to a third embodiment on an image forming apparatus main body. FIG. 10 is a cross-sectional view illustrating a process in the middle of mounting a process cartridge according to a third embodiment on an image forming apparatus main body. FIG. 10 is a cross-sectional view illustrating a state in which a process cartridge according to a third embodiment is completely attached to the image forming apparatus main body.

Explanation of symbols

L1 ... Gap L2, L3 ... Separation amount S ... Recording sheet T, T2 ... Gap 1 ... Photosensitive drum 2 ... Charging roller 3 ... Scanner unit 4 ... Development unit 4e ... Force receiving part 4f ... Supporting part 4h ... Contact part 4i鉤 shape portion 6 ク リ ー ニ ン グ cleaning member 7 プ ロ セ ス process cartridge 11 転 写 transfer belt 15 ２ secondary transfer roller 17 カ セ ッ ト cassette 18 給 feed roller 19 搬 送 transport roller 20 定 着 fixing portion 23 排出 discharge roller… photoconductor unit 26 ｆ shaft 26g ... wall surfaces 26h, 26i ... slide groove 26j ... projection 26k ... contact part 27 ... cleaning frame 27b ... hole 37 ... shaft 40 ... developing roller 50, 51 ... separation member 50a ... shaft 50c, 51b ... contact part 50b ... Engagement part 51a ... regulation part 53 ... pressurizing spring (biasing member)
57, 58 ... separation release contact portion 60 ... protective cover (separation member)
60a, 60b ... slide rib 60c ... separation holding part 60d ... handle part 61 ... inclined parts 62 and 63 ... cover member 80 ... rotating shaft 100 ... image forming apparatus main body 100b ... engagement part 111 ... separation cam (action member)
111c ... large diameter part

Claims (11)

In an electrophotographic image forming apparatus capable of forming an image on a recording medium,
A process cartridge having a photoconductor, a developing roller capable of contacting and separating from the photoconductor, and a force receiving portion for receiving a force for separating the photoconductor and the developing roller;
A separation member that is attached to a predetermined position of the process cartridge so as to separate the photosensitive member and the developing roller, and that can be retracted from the predetermined position to contact the photosensitive member and the developing roller;
A mounting portion to which the process cartridge can be mounted;
An abutting member that abuts the spacing member and retracts the spacing member from the predetermined position until the mounting process of the process cartridge to the mounting portion is completed;
A first position for biasing the force to the force receiving portion to separate the developing roller and the photosensitive member, and a first position for bringing the developing roller and the photosensitive member into contact with each other. A force applying member that is movable between the retracted second position and a force applying member that maintains the first position at any point in the mounting process;
Have
The force applying member positioned at the first position in a state in which the spacing member is retracted from the predetermined position when the mounting process is started with the spacing member being mounted at the predetermined position; The mounting process is configured to be completed in a state where the force receiving portion is in contact, and the photosensitive member and the developing roller are configured not to contact at any point in the mounting process. An electrophotographic image forming apparatus.   In the mounting process, after the contact member retracts the separation member from the predetermined position, the force applying member positioned at the first position without the contact between the photosensitive member and the developing roller; The electrophotographic image forming apparatus according to claim 1, wherein the electrophotographic image forming apparatus is configured to come into contact with the force receiving portion.   The distance between the developing roller and the photosensitive member separated by the separation member is larger than the distance between the developing roller and the photosensitive member separated by the force applying member located at the first position. The electrophotographic image forming apparatus according to claim 2.   In the mounting process, the contact member is configured to retract the separation member from the predetermined position after the force applying member positioned at the first position and the force receiving portion contact each other. The electrophotographic image forming apparatus according to claim 1.   The distance between the developing roller and the photoconductor separated by the separating member is smaller than the distance between the developing roller and the photoconductor separated by the force applying member located at the first position. The electrophotographic image forming apparatus according to claim 4.   6. The electron according to claim 4, further comprising an inclined portion that comes into contact with the force receiving portion in order to guide the force receiving portion to the force applying member in front of the force applying member in the mounting direction. Photo image forming apparatus.   5. The process cartridge according to claim 4, further comprising an inclined portion that comes into contact with the force applying member to guide the force applying member to the force receiving portion at the back of the force receiving portion in the mounting direction. 5. The electrophotographic image forming apparatus according to 5. 2. The process cartridge according to claim 1, wherein the separation member is attached to a main body of the process cartridge so as to be retracted from the predetermined position to a retracted position for bringing the photosensitive member and the developing roller into contact with each other. The electrophotographic image forming apparatus described in 1. The spacer member is an electrophotographic image forming apparatus according to claim 8, characterized in that relative to the body of the process cartridge is pivotable to said retracted position from the predetermined position.   The electrophotographic image forming apparatus according to claim 1, wherein the separation member is a member that is removable from a main body of the process cartridge.   The electrophotographic image forming apparatus according to claim 10, wherein the separation member includes a cover portion that protects the photoconductor when attached to the predetermined position.

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