JP2012053402A - Process cartridge and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that the positioning accuracy of the photoreceptor drum of a process cartridge decreases relative to a body due to component tolerance, and in order to fix the process cartridge relative to the body, the process cartridge is pressed in the direction of insertion by use of a pressing member such as a spring, however, load due to torque during driving or paper passage is greater than the pressure of the pressing member, with the result that the position of the process cartridge changes, and may end up disturbing an image.SOLUTION: When a coupling slides and engages with a photoreceptor drum, the coupling causes a drum shaft to slide, thereby engaging the apparatus body and drum shaft and hence positioning a photoreceptor drum to the apparatus body. Since the apparatus body and drum shaft are directly engaged and positioned, the positioning accuracy of the photoreceptor drum is improved. Since both ends of the drum shaft are engaged with the body, the position of the process cartridge can be stabilized even if external force is exerted on the process cartridge during paper passage, distribution, or the like.

Description

  The present invention relates to a process cartridge and an image forming apparatus in which the process cartridge is detachably mounted.

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

  In the conventional example, when the process cartridge is mounted on the apparatus main body, the main body coupling held by the apparatus main body slides in the axial direction of the photosensitive drum. As a result, the photosensitive drum coupling held on the photosensitive drum and the main body coupling are engaged with each other, and printing is enabled. When the process cartridge is taken out from the apparatus main body, the main body coupling slides in a direction to release the engagement with the photosensitive drum coupling. As a result, the process cartridge can be removed from the apparatus main body (Patent Document 1).

  There is also a method of positioning the process cartridge in the main body by sliding it in the photosensitive drum axial direction after the main body is inserted. (Patent Document 2)

JP 2001-92333 A JP-A-8-305259

  However, in the conventional example, the position of the photosensitive drum with respect to the apparatus main body is determined by the coupling bearing, the coupling, and the photosensitive drum coupling on the driving side with respect to the main body frame. On the other hand, the position on the non-driving side is determined by the main body frame, the process cartridge guide, the process cartridge frame, the photosensitive drum shaft, and the photosensitive drum bearing. Thus, on the non-driving side, the photosensitive drum is positioned with respect to the main body frame through a plurality of components such as a component that holds the photosensitive drum, a component that guides the process cartridge, and a driving component that rotates the photosensitive drum. Therefore, these component tolerances may affect the accuracy of positioning the process cartridge with respect to the main body frame.

  Further, in order to fix the process cartridge to the main body, the process cartridge is biased in the insertion direction by using a biasing member such as a spring. However, there is a possibility that the position of the process cartridge may fluctuate due to the driving torque or the load due to paper passing over the pressing force of the urging member.

  Further, when transported with the process cartridge mounted in the apparatus main body, it is necessary to add a part for preventing the process cartridge from moving due to an external force during distribution, resulting in an increase in cost.

  Further, in the case of a configuration in which the process cartridge is slid, it is necessary to secure a space for that purpose, and the main body size becomes large.

  In order to solve the above-described object, an invention according to the present application is a process cartridge that is attachable to and detachable from an image forming apparatus main body, and is in the axial direction of the photosensitive drum with respect to the photosensitive drum and the photosensitive drum. A drum shaft penetrating the photosensitive drum, which is movably provided, and provided on one end side in the axial direction, when the process cartridge is mounted on the image forming apparatus main body, the image forming apparatus A pressed portion that receives a pressing force in the axial direction from the main body, and the pressed portion that is provided on the other end side in the axial direction when the process cartridge is mounted on the main body of the image forming apparatus. An engaged portion that engages with an engaging portion provided in the image forming apparatus main body by receiving pressure, wherein the process cartridge is moved relative to the image forming apparatus main body. And engaged portions for positioning in the direction orthogonal to the line direction, and the drum shaft having, and having a.

  As described above, since the process cartridge is positioned by directly engaging the through shaft of the apparatus main body and the photosensitive drum, the position of the photosensitive drum with respect to the apparatus main body can be determined with few parts. It can be determined with high accuracy. In addition, the process cartridge can be stably fixed to the apparatus main body even when the process cartridge is transported while being mounted on the apparatus main body. Furthermore, since only the through shaft of the photosensitive drum slides, a space for sliding the process cartridge is not required, and the size of the main body can be reduced.

1 is a diagram illustrating an image forming apparatus according to a first embodiment. (A) Cross-sectional view of the center of the photosensitive drum in the printable state according to the first embodiment, (b) Enlarged view of the non-driving side in the cross-sectional view of the center of the photosensitive drum in the printable state according to the first embodiment. (C) Enlarged view of the drive side in the cross-sectional view of the center of the photosensitive drum in the printable state according to the first embodiment. (A) A cross-sectional view of the center of the photosensitive drum in a state where the process cartridge can be removed according to the first embodiment, and (b) a non-drive state in a cross-sectional view of the center of the photosensitive drum where the process cartridge can be removed according to the first embodiment. (C) Enlarged view of the drive side in the cross-sectional view of the center of the photosensitive drum in the state where the process cartridge can be taken out according to the first embodiment. (A) Cross-sectional view of the center of the photosensitive drum in the printable state according to the second embodiment, (b) Enlarged view of the non-driving side in the cross-sectional view of the center of the photosensitive drum in the printable state according to the second embodiment. (C) Enlarged view of the drive side in the cross-sectional view of the center of the photosensitive drum in the printable state according to the second embodiment. (A) A cross-sectional view of the center of the photosensitive drum in a state where the process cartridge can be taken out according to the second embodiment, (b) a non-drive state in a cross-sectional view of the center of the photosensitive drum where the process cartridge can be taken out according to the second embodiment. (C) Enlarged view of the drive side in the cross-sectional view of the center of the photosensitive drum in a state where the process cartridge can be taken out according to the second embodiment. (A) Cross-sectional view of the center of the photosensitive drum in the printable state according to the third embodiment, (b) Enlarged view of the non-driving side in the cross-sectional view of the center of the photosensitive drum in the printable state according to the third embodiment. (A) A cross-sectional view of the center of the photosensitive drum in a state where the process cartridge can be taken out according to the third embodiment, (b) A non-drive state in a cross-sectional view of the center of the photosensitive drum where the process cartridge can be taken out according to the third embodiment. Enlarged view of the side

Example 1
An embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a diagram illustrating a schematic configuration of an image forming apparatus M in which a photosensitive drum of an image forming cartridge is driven by coupling of a main body according to an embodiment of the present invention.

  In FIG. 1, the right side is the front side of the main body, and the left side is the back side of the main body. The paper 2 that is the recording medium before printing stored in the paper feed cassette 1 that can be inserted and removed in the front direction of the main body is fed one by one by the paper feed unit 3 and conveyed to the conveyance roller pair 5 by the conveyance path 4. . On the other hand, the charging roller 6a charges the photosensitive drum 6b, and a latent image is formed on the photosensitive drum 6b by the laser light 8 emitted from the laser unit 7. Then, a toner image is formed on the latent image portion of the photosensitive drum 6b by the developing device 6c. Thereafter, the toner image formed on the photosensitive drum 6b is transferred to the paper 2 by the transfer roller 9, and the toner that has not been transferred is collected inside the process cartridge 6 by the cleaner means 6d. The paper 2 on which the toner image is transferred is fixed on the paper 2 by the fixing device 10. Thereafter, the paper 2 is conveyed to the front side of the main body by the paper discharge roller 11 and is discharged from the image forming apparatus M. As shown in FIG. 1, the photosensitive drum 6 b, the charging roller 6 a, and the cleaner unit 6 d are held by the cartridge frame 19. Then, it is integrally formed as a process cartridge 6 together with the developing device 6 c, and is configured to be detachable from the apparatus main body 13 along the non-driving side guide 12 and the driving side guide 36.

  2A and 3A are longitudinal sectional views of the main body frame at the center of the photosensitive drum 6b. 2B and 3B are enlarged views on the non-driving side, and FIGS. 2C and 3C are enlarged views on the driving side. In the present embodiment, the process cartridge 6 has a drum shaft 14 that penetrates the photosensitive drum 6b and is provided so as to be movable in the axial direction of the photosensitive drum 6b. The drum shaft 14 has a first position (FIG. 2a) engaged with an engaging portion 15a formed on the non-driving main body frame 15, and a second position (FIG. 3a) separated from the engaging portion 15a. Can be moved to. Here, the drum shaft 14 has an engaged portion 14b that engages with the engaging portion 15a.

  The photosensitive drum 14 is rotatably held on the drum shaft 14 via a drum coupling 16 provided on one end side in the axial direction of the photosensitive drum 14 and a drum bearing 17 provided on the other end side. ing. The drum shaft 14 is provided with a receiving portion 14a. The urging member 18 is disposed between the drum bearing 17 and the receiving portion 14a of the drum shaft 14, and urges the drum shaft 14 in the direction of the arrow in FIG. The cartridge frame 19 is held by the drum coupling 16 and the drum shaft 14. The non-driving side guide 12 is held by the non-driving side main body frame 15, and the driving side guide 36 is held by the driving main body frame 35, and regulates the attaching / detaching direction of the process cartridge 6. The main body coupling 20 is held by a coupling bearing 21 held by the drive main body frame 15, and is moved in the direction of the arrow in FIG. 2A by a cam (not shown) interlocked with an opening / closing operation of a main body door (not shown). The non-driving side main body frame 15 has an engaging portion 15 a that engages with the drum shaft 14.

The process cartridge 6 is guided by the non-driving side guide 12 and the driving side guide 36 and inserted to a predetermined position in the main body. By the operation of closing the main body door (not shown), the cam (not shown) slides the main body coupling 20 in the direction of the arrow in FIG. As a result, the main body coupling 20 and the drum coupling 16 are engaged with each other to be connected to a drive mechanism (not shown). Further, since the main body coupling 20 abuts on the drum shaft 14, the pressed portion 14c provided on the other end side in the axial direction of the drum shaft 14 receives a pressing force from the main body coupling 20, and is shown in FIG. Slide in the direction of the arrow, which is the axial direction. Then, the engaging portion 15a of the non-driving side main body frame 15 and the engaging portion 14b of the drum shaft 14 are engaged, so that the positioning of the process cartridge 6 in the direction intersecting the axial direction is performed. Is done. (First position)
When the process cartridge 6 is taken out, an unillustrated cam slides the main body coupling 20 in the direction of the arrow in FIG. 3C by opening the main body door (not shown), and the engagement between the coupling 30 and the drum coupling 16 is performed. The match is released. The drum shaft 14 is slid in the direction of the arrow in FIG. 3C by the urging means 18 and moved to a position away from the engaging portion 15a of the non-driving side main body frame 15. (Second position). Therefore, the process cartridge 6 can be taken out from the apparatus main body 13.

  The photosensitive drum 6 b is held by the drum shaft 14 via the drum bearing 17 and the drum coupling 16, and the drum shaft 14 is directly engaged with the main body frame engaging portion 15 a and the main body coupling 20. Therefore, the position of the photosensitive drum 6b is determined with respect to the non-driving side main body frame 15 through a small number of parts, so that the part tolerance can be reduced, the position can be determined with high accuracy, and accurate printing can be realized. Further, since the drum shaft 14 is engaged with the non-driving side main body frame 15, the position of the photosensitive drum 6b does not move due to the external force applied to the photosensitive drum 6b due to the rigidity of the paper during printing. A biasing means such as a spring for biasing the cartridge 6 is not necessary.

Further, in order to save space during distribution, the process cartridge 6 may be shipped (transported) with the process cartridge 6 mounted in the apparatus main body 13.
In this embodiment, since the process cartridge 6 is engaged with the non-driving side main body frame 15 and the main body coupling 20, the process cartridge 6 does not jump out of the apparatus main body 13 due to an impact during distribution. For this reason, there is no need for a cushioning material to be inserted into the apparatus main body 13 in order to prevent the process cartridge 6 from jumping out of the apparatus main body 13, and cost reduction can be realized.

  Further, as compared with the case where the entire process cartridge 6 is slid, only the drum shaft 14 is slid by the main body coupling 20 for transmitting the driving force to the photosensitive drum 6 b after being inserted into the apparatus main body 13. Therefore, since the opening of the apparatus main body 13 is not widened and there is no need for a space for sliding the process cartridge, the apparatus main body can be downsized. Furthermore, the sliding force is small.

(Example 2)
An embodiment of the present invention will be described with reference to FIGS. In addition, the same code | symbol is attached | subjected to a common location with Example 1, and description is abbreviate | omitted. 4A and 5A are longitudinal sectional views of the apparatus main body at the center of the photosensitive drum 6b. 4 (b) and 5 (b) are enlarged views on the non-driving side, and FIGS. 4 (c) and 5 (c) are enlarged views on the driving side. A characteristic point different from the first embodiment is that the contact member 22 also serves as an urging means.

The contact holding member 23 is provided in the non-driving side apparatus main body 15 and holds the contact member 22 which is an urging connection means.
The contact member 22 is a conductor and is electrically connected to the drum shaft 24 at the first position. Further, the contact member 22 is provided at a position lower than the b surface of the process cartridge guide 25.

  The drum bearing 17, the drum shaft 24, the drum bearing 17, the drum shaft 24, the contact member 22, and the contact holding member 23 are conductors. The non-driving side body frame pair 15 is metal.

  In the present embodiment, the process cartridge 6 is guided by the non-driving side guide 25 and the driving side guide 36 and mounted to a predetermined position in the apparatus main body M. By the operation of closing the main body door (not shown), the cam (not shown) slides the main body coupling 20 in the direction of the arrow in FIG. By sliding, the main body coupling 20 is engaged with the drum shaft 24, and the main body coupling 20 and the drum coupling 16 are engaged with each other, thereby being connected to a drive mechanism (not shown). The main body coupling 20 abuts on the pressed portion 24 c of the drum shaft 24. Then, the drum shaft 24 slides in the direction of the arrow in FIG. 4A, and the engaged portion 24b of the drum shaft 24 is engaged with the engaging portion 15a of the non-driving side main body frame 15 (first position). Position of). Further, the contact member 22 and the drum shaft 24 come into contact with each other and are brought into conduction. Therefore, the photosensitive drum 6 b is grounded through the path of the drum bearing 17, the drum shaft 24, the contact member 22, the contact holding member 23, and the non-driven main body frame 15.

  When the process cartridge 6 is taken out, an unillustrated cam slides the main body coupling 20 in the direction of the arrow in FIG. 5A by opening the main body door (not shown), and the main body coupling 20 and the drum coupling 16 are moved. The engagement is released. The drum shaft 24 is slid by the contact member 22 in the direction of the arrow in FIG. 5A, and the engaged portion 24b moves to a position away from the engaging portion 15a of the non-driving side main body frame 15 (second second). position). Therefore, the process cartridge 6 is released from the main body and can be removed from the main body. When the process cartridge 6 is removed from the main body, there is no means for urging the drum shaft 24, and the drum shaft 24 may slide in the direction of the arrow in FIG. However, when inserting the process cartridge 6 into the apparatus main body, the protruding drum shaft 24 is returned in the direction of the arrow in FIG. Will not be damaged.

  When the process cartridge 6 is taken out from the apparatus main body, the contact member 22 is at a position lower than the b surface of the non-driving side guide 25. Therefore, when the user puts his hand in the main body due to a paper jam processing or the like, it is possible to prevent contact failure due to contamination of the contact.

  Further, since the contact member 22 also serves as an urging means, the number of parts can be reduced, and implementation can be performed at low cost.

(Example 3)
An embodiment of the present invention will be described with reference to FIGS. In addition, the same code | symbol is attached | subjected to a common location with Example 1 and Example 2, and description is abbreviate | omitted. 6A and 7A are longitudinal sectional views of the apparatus main body at the center of the photosensitive drum 6b. 6B and 7B are enlarged views on the non-driving side, and FIGS. 6C and 7C are enlarged views on the driving side.

  A characteristic point different from the first and second embodiments is that the drum shaft 26 is provided with storage means 27 for storing information relating to the process cartridge and the apparatus main body, and the storage means 27 and the apparatus main body are electrically connected. The electrical connection means 28 is provided in the main body 14.

  The drum shaft 26 is provided with a storage means 27 at an end portion and a receiving portion 26a. Further, it is provided in the process cartridge frame 19 so that the phase in the rotation direction is constant.

The storage unit 27 stores information on the process cartridge and the apparatus main body.
The electrical connection means 28 is provided in the non-driving side main body frame 15 at a position where the storage means 27 and the apparatus main body are electrically connected and retracted lower than the non-driving side guide 25.

  In the present embodiment, the process cartridge 6 is guided by the non-driving side guide 25 and inserted to a predetermined position in the main body. By the operation of closing the main body door (not shown), the cam (not shown) slides the main body coupling 20 in the direction of the arrow in FIG. By sliding, the main body coupling 20 is engaged with the drum shaft 26, and the main body coupling 20 and the drum coupling 16 are engaged with each other, thereby being connected to a drive mechanism (not shown). The main body coupling 20 abuts on the pressed portion 26 c of the drum shaft 26. Then, the drum shaft 26 slides in the direction of the arrow in FIG. 6A, and the engaged portion 26b of the drum shaft 26 is engaged with the engaging portion 15a of the non-driving side main body frame 15 to determine the position (first). Position of). Further, the storage means 27 and the electrical connection means 28 are connected. The electrical connection means 28 performs electrical communication with a control unit (not shown) of the apparatus body via a lead wire (not shown).

  When the process cartridge 6 is taken out, an unillustrated cam slides the main body coupling 20 in the direction of the arrow in FIG. 7A by opening the main body door (not shown), and the main body coupling 20 and the drum coupling 16 are moved. The engagement is released. The drum shaft 24 is slid by the urging means 18 in the direction of the arrow in FIG. 7A, and the engaged portion 26b moves to a position away from the engaging portion 15a of the non-driving side frame 15 (second second). position). Therefore, the process cartridge 6 is released from the main body and can be removed from the main body. Further, the electrical connection between the storage means 27 and the electrical connection means 28 is released.

  When the process cartridge 6 is taken out, the electrical connection means 28 is located at a position lower than the b surface of the non-driving side guide 25. Therefore, when the user puts his / her hand into the main body due to a paper jam processing or the like, it is possible to prevent electrical connection failure due to contamination or deformation of the electrical connection means. In addition, troubles to the electrical connection means due to static electricity or the like possessed by the user do not occur. In addition, since the electrical connecting means 28 moves following the movement of the storage means 27 in the drum axis direction, the contact pressure is stable, and the drum shaft 26 holding the storage means 27 is engaged with the apparatus main body 14 and slides. High positional accuracy can be obtained.

6 Process Cartridge 13 Main Body 14 Drum Shaft 14a Receiving Part 15 Non-Drive Side Frame 15a Engaging Part 16 Photosensitive Drum Coupling 17 Drum Bearing 18 Biasing Member 19 Cartridge Frame 20 Coupling 21 Coupling Bearing 22 Contact Member 23 Contact holding member 24 Drum shaft 25 Non-driving side guide 26 Drum shaft 26a Receiving portion 27 Storage means 28 Electrical connection means 29 Process cartridge 29b Photosensitive drum 30 Non-driving side guide 31 Main body 32 Process cartridge frame 33 Drum shaft 34 Coupling 35 Driving device main body 36 Driving side guide 37 Non-driving main body frame 38 Non-driving side guide

Claims (8)

A process cartridge that can be attached to and detached from the image forming apparatus main body,
A photosensitive drum;
The process cartridge, which is provided on one end side in the axial direction, is a drum shaft that penetrates the photosensitive drum and is provided so as to be movable in the axial direction of the photosensitive drum with respect to the photosensitive drum. And a pressed part that receives a pressing force in the axial direction from the image forming apparatus main body when mounted on the main body of the image forming apparatus, and the process cartridge provided on the other end side in the axial direction. An engaged portion that engages with an engaging portion provided in the image forming apparatus main body by receiving the pressing force when the pressed portion is attached to the apparatus main body, wherein the process cartridge is A drum shaft having an engaged portion that positions the image forming apparatus main body in a direction crossing the axial direction;
A process cartridge.   One end of the photosensitive drum in the axial direction is engaged with a main body coupling provided in the image forming apparatus main body when the process cartridge is mounted in the image forming apparatus main body, and the photoconductor A drum coupling to which a driving force for driving a drum is transmitted, wherein a drum coupling through which the drum shaft passes is provided, and the pressed portion receives the pressing force from the main body coupling. The process cartridge according to claim 1.   The process cartridge according to claim 1, wherein the photosensitive drum includes a biasing member that biases the drum shaft from the other end side toward the one end side in the axial direction.   On the other end side of the drum shaft, there is a storage means for communicating with the apparatus main body by connecting to an electrical connection means provided in the apparatus main body when the process cartridge is mounted on the image forming apparatus main body. The process cartridge according to claim 1, further comprising a process cartridge. In an image forming apparatus for forming an image on a recording medium,
(A) an engaging portion;
(B) a process cartridge detachably attached to the main body of the image forming apparatus,
A photosensitive drum;
The process cartridge, which is provided on one end side in the axial direction, is a drum shaft that penetrates the photosensitive drum and is provided so as to be movable in the axial direction of the photosensitive drum with respect to the photosensitive drum. And a pressed part that receives a pressing force in the axial direction from the apparatus main body and the process cartridge provided on the other end side in the axial direction when mounted on the apparatus main body. When the pressed portion receives the pressing force, the pressed portion engages with the engaging portion, and the process cartridge is positioned relative to the apparatus main body in a direction crossing the axial direction. A drum shaft having an engaged portion that performs
A process cartridge having
(C) conveying means for conveying the recording medium;
An image forming apparatus comprising:   Further, the image forming apparatus engages with a drum coupling provided on one end side in the axial direction of the photosensitive drum when the process cartridge is mounted on the apparatus main body, and drives the photosensitive drum. A main body coupling for transmitting a driving force to be moved, wherein the main body coupling moves in the axial direction and presses the pressed portion when the process cartridge is mounted on the apparatus main body. The image forming apparatus according to claim 5.   The image forming apparatus according to claim 5, further comprising an urging member that urges the drum shaft from the other end side toward the one end side in the axial direction. apparatus.   Further, the image forming apparatus is connected to a storage means provided on the other end side of the drum shaft and communicates with the apparatus main body when the process cartridge is mounted on the apparatus main body. The image forming apparatus according to claim 5, further comprising:

Images