JP2005099231A - Processing cartridge and electrophotographic image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a retaining means for preventing a through-hole shaft supporting a photoreceptor drum from being moved in the direction of thrust, in which retaining performance for image formation and distribution is improved and space is saved in its longitudinal direction. <P>SOLUTION: A processing cartridge which is attachable/detachable to/from an electrophotographic image forming apparatus main body includes: the electrophotographic photoreceptor drum; a cleaning frame which holds the electrophotographic photoreceptor drum; the through-hole shaft which is connected to the drum to support it; bearing members which fit on the through-hole shaft in order to support the through-hole shaft in the cleaning frame so that the through-hole shaft freely rotates; a coupling member which transmits drive from the electrophotographic image forming apparatus main body to the through-hole shaft. A projection larger in diameter than the bearing member fitted on the through-hole shaft is formed on the through-hole shaft at the end which is longitudinally opposite to the coupling member. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a process cartridge and an electrophotographic image forming apparatus using the same. In particular, it is suitable for application to a color electrophotographic image forming apparatus.

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

  The process cartridge is a cartridge in which a charging unit, a developing unit or a cleaning unit and an electrophotographic photosensitive drum are integrally formed, and the cartridge can be attached to and detached from the main body of the electrophotographic image forming apparatus. In addition, at least one of the charging unit, the developing unit, and the cleaning unit 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. Further, it means that at least the developing means and the electrophotographic photosensitive drum are integrated into a cartridge so that it can be attached to and detached from the main body of the electrophotographic image forming apparatus.

  In the electrophotographic image forming apparatus, the photosensitive drum uniformly charged by the charging unit is selectively exposed to form a latent image on the surface of the photosensitive drum. Then, the latent image is visualized with a developer (toner) supplied from the developing means, transferred to a recording medium, and further fixed with an image such as heat or pressure to record an image on the recording medium. Yes.

  Further, the developer remaining on the photosensitive drum after the transfer is removed by a cleaning means such as a cleaning blade and stored as a residual developer (removed toner) in the cleaning container. The next development can be performed without remaining.

  In such an electrophotographic image forming apparatus, the electrophotographic photosensitive drum and the process means acting on the electrophotographic photosensitive drum are integrally formed into a cartridge, and the process cartridge is detachable from the main body of the electrophotographic image forming apparatus. The method is adopted.

  According to this process cartridge system, the user can replace the cartridge himself without relying on a service person, so that the operability can be remarkably improved. As a result, consumable parts such as the photosensitive drum and developer can be replaced without maintenance by a service person. Therefore, the process cartridge system is widely used in electrophotographic image forming apparatuses.

The photosensitive drum is configured by fixing a flange to an end portion of a cylindrical conductive substrate having a photosensitive layer on the surface. The photosensitive drum is supported so as to be rotatable integrally with a through shaft that is rotatably supported by a bearing portion disposed at a predetermined position of the cartridge housing. Drive transmission means for rotating the photosensitive drum in response to driving from the image forming apparatus main body is provided on one end side of the through shaft. Further, the photosensitive drum is urged in one longitudinal direction, and a longitudinal position is determined by being abutted against a part of the cartridge housing. A thrust retaining member that can be attached to the penetrating shaft is provided so that the photosensitive drum and the support shaft do not move by a predetermined amount or more (see, for example, Patent Document 1).
JP 2002-189384 (page 3, FIG. 10-11)

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

  For example, in the case where the cleaning blade is in contact with the photosensitive drum as the cleaning means, it is desirable to suppress the thrust movement of the photosensitive drum as much as possible to prevent image defects such as a rubbing memory. However, the conventional retaining member for restricting the thrust movement is attached to the through shaft as a separate member. In this configuration, the retaining member is detached due to excessive vibration that may occur at the time of physical distribution or an error during assembly. There was a danger. In addition, there is a problem that the longitudinal space must be increased by attaching another member in consideration of accumulation of dimensional tolerances, assembling property, and the like.

  An object of the present invention is to reduce the amount of movement in the thrust direction of the photosensitive drum, the support shaft, and the drive transmission means of the process cartridge by integrating the member that suppresses the amount of movement in the thrust direction with the support shaft. It is intended to prevent image defects such as memory and the like, and to enhance the removal strength of the retaining member for restricting the thrust movement, thereby saving the space of the drive transmission unit.

A typical configuration of a process cartridge and an electrophotographic image forming apparatus according to the present invention for solving the above problems is a process cartridge that is detachable from an electrophotographic image forming apparatus main body, and an electrophotographic photosensitive drum;
A cleaning frame that holds the electrophotographic photosensitive drum, a through shaft that is coupled to and supported by the electrophotographic photosensitive drum, and a through shaft that rotatably supports the through shaft on the cleaning frame. A bearing member to be fitted, and a coupling member for transmitting driving from the electrophotographic image forming apparatus main body to the through shaft; the through shaft has the coupling member at the end opposite to the longitudinal direction of the coupling member; A protrusion having a larger diameter than the fitting diameter of the bearing member with the penetrating shaft is provided.

  As described above, in the process cartridge in which the photosensitive drum and the penetrating shaft are rotatably supported integrally with the cleaning frame, and the penetrating shaft extends outward in the longitudinal direction from the bearing member, one end of the penetrating shaft On the side, an end face coupling for transmitting drive from the main body of the image forming apparatus is provided, and on the other end side, a projection larger than the fitting diameter of the bearing member and the through shaft is integrated with the through shaft on the outer side in the longitudinal direction. Is provided. Providing the protrusion for preventing thrust removal integrally with the penetrating shaft can significantly improve the retaining performance for restricting movement in the thrust direction. Further, it is possible to reduce the space in the thrust direction necessary for disposing the retaining member. This prevents sliding memory between the photosensitive drum and the process means that contacts the photosensitive drum, strengthens the removal strength of the retaining member for restricting the thrust movement, and saves space in the drive transmission unit. Can be planned.

(Example 1)
Embodiments of a multicolor image forming apparatus according to the present invention will be described below in detail with reference to the drawings.

[Overall configuration of multicolor image forming apparatus]
First, the overall configuration of the multicolor image forming apparatus will be outlined with reference to FIGS. FIG. 1 is a longitudinal sectional view showing the entire configuration of a full-color laser beam printer 100 which is an embodiment of a multicolor image forming apparatus, and FIG. 2 is a main section of a process cartridge 7 containing toner.

  A multicolor image forming apparatus 100 shown in FIG. 1 includes four photosensitive drums 1a, 1b, 1c, and 1d arranged in parallel in the vertical direction. The photosensitive drum 1 is driven to rotate counterclockwise in the drawing by a driving means (not shown). A charging device 2 (2a, 2b, 2c, 2d) for uniformly charging the surface of the photosensitive drum 1 in order according to the rotation direction, and a laser beam is irradiated around the photosensitive drum 1 based on image information. A scanner unit 3 (3a, 3b, 3c, 3d) for forming an electrostatic latent image on the drum 1, and a developing device 4 (4a, 4b, 4c, 4d) for developing the toner image by attaching toner to the electrostatic latent image ), An electrostatic transfer device 5 that transfers the toner image on the photosensitive drum 1 to the transfer material S, and a cleaning device 6 (6a, 6b, 6c, which removes transfer residual toner remaining on the surface of the photosensitive drum 1 after transfer). 6d) and the like are provided.

  Here, the photosensitive drum 1, the charging device 2, the developing device 4, and the cleaning device 6 are integrated into a cartridge to form a process cartridge 7.

  Hereinafter, the photosensitive drum 1 will be described in detail.

  The photosensitive drum 1 is configured by providing a photosensitive layer on the outer peripheral surface of an aluminum cylinder having a diameter of 30 mm, for example. Both ends of the photosensitive drum 1 are rotatably supported by a support member, and a driving force from a driving motor (not shown) is transmitted to one end, so that the photosensitive drum 1 is rotated counterclockwise. The

  As the charging device 2, a contact charging type can be used. The charging member is a conductive roller formed in a roller shape. The roller is brought into contact with the surface of the photosensitive drum 1 and the surface of the photosensitive drum 1 is made uniform by applying a charging bias voltage to the roller. To be charged. In this embodiment, since the reversal development system is used, the surface of the photosensitive drum 1 is charged with a negative polarity.

  The scanner unit 3 is arranged in a substantially horizontal direction of the photosensitive drum 1, and image light corresponding to an image signal is rotated at high speed by a scanner motor (not shown) by a laser diode (not shown). 9b, 9c, 9d). The image light reflected by the polygon mirror 9 selectively exposes the surface of the charged photosensitive drum 1 through the imaging lens 10 (10a, 10b, 10c, 10d) to form an electrostatic latent image. It is composed.

  The developing device 4 includes toner containers 41 (41 a, 41 b, 41 c, 41 d) that respectively store yellow, magenta, cyan, and black toners, and the toner in the toner container 41 is supplied by a feeding mechanism 42 to a toner supply roller. 2 and rotated in the clockwise direction (arrow Y direction) shown in FIG. 2 by the toner supply roller 43 rotating in the clockwise direction (arrow Z direction) shown in FIG. 2 and the developing blade 44 pressed against the outer periphery of the developing roller 40. A toner is applied to the outer periphery of the developing roller 40 and an electric charge is applied to the toner.

  Then, a developing bias is applied to the developing roller 40 facing the photosensitive drum 1 on which the latent image is formed, whereby toner development is performed on the photosensitive drum 1 in accordance with the latent image.

  The electrostatic transfer device 5 is provided with an electrostatic conveyance belt 11 that circulates and moves so as to face and contact all the photosensitive drums 1a, 1b, 1c, and 1d. The electrostatic transport belt 11 is made of a resin film or a multilayer film member having a resin layer provided on a rubber base layer. The electrostatic conveyance belt 11 is stretched around a driving roller 13, driven rollers 14a and 14b, and a tension roller 15, and electrostatically attracts the transfer material S to the left outer peripheral surface of the electrostatic conveyance belt 11 shown in FIG. Then, the transfer material S is circulated so as to come into contact with the photosensitive drum 1. As a result, the transfer material S is conveyed to the transfer position by the electrostatic transfer belt 11, and the toner image on the photosensitive drum 1 is transferred.

  The transfer roller 12 (12a, 12b, 12c, 12d) is arranged in parallel at a position in contact with the inside of the electrostatic transfer belt 11 and facing the four photosensitive drums 1a, 1b, 1c, 1d. A positive polarity bias is applied to the transfer rollers 12 during transfer, and positive polarity charges are applied to the transfer material S via the electrostatic transfer belt 11. The negative polarity toner image on the photosensitive drum 1 is transferred to the transfer material S in contact with the photosensitive drum 1 by the electric field generated at this time.

  The paper feed unit 16 feeds and conveys the transfer material S to the image forming unit, and a plurality of transfer materials S are stored in the paper feed cassette 17. At the time of image formation, the paper feed roller 18 (half-moon roller) and the registration roller pair 19 are driven and rotated in accordance with the image forming operation to separate and feed the transfer material S in the paper feed cassette 17 one by one and , Abuts against the registration roller pair 19 and temporarily stops. After forming a loop, the rotation of the electrostatic transfer belt 11 and the image writing position are synchronized, and the sheet is fed to the electrostatic transfer belt 11 by the registration roller pair 19. .

  The fixing unit 20 fixes a plurality of color toner images transferred to the transfer material S, and includes a heating roller 21a that rotates, and a pressure roller 21b that presses and applies heat and pressure to the transfer material S. Consists of.

  That is, the transfer material S to which the toner image on the photosensitive drum 1 is transferred is conveyed by the fixing roller pair 21 when passing through the fixing unit 20, and is given heat and pressure by the fixing roller pair 21. As a result, the toner images of a plurality of colors are fixed on the surface of the transfer material S.

  As an image forming operation, the process cartridges 7a, 7b, 7c, and 7d are sequentially driven in accordance with the print timing, and the photosensitive drums 1a, 1b, 1c, and 1d are rotated counterclockwise in accordance with the drive. Driven. Then, the scanner units 3 corresponding to the respective process cartridges 7 are sequentially driven. By this driving, the charging roller 2 imparts a uniform charge to the circumferential surface of the photosensitive drum 1, and the scanner unit 3 exposes the circumferential surface of the photosensitive drum 1 according to the image signal to perform photosensitive drum 1. An electrostatic latent image is formed on the peripheral surface. The developing roller 40 in the developing device 4 forms (develops) a toner image on the circumferential surface of the photosensitive drum 1 by transferring the toner to the low potential portion of the electrostatic latent image.

  At the timing when the leading edge of the toner image on the circumferential surface of the uppermost photosensitive drum 1 is rotated and conveyed to a point facing the electrostatic transfer belt 11, the printing start position of the transfer material S coincides with that point. Then, the registration roller pair 19 starts rotating to feed the transfer material S to the electrostatic transfer belt 11.

  The transfer material S is pressed against the outer periphery of the electrostatic transfer belt 11 so as to be sandwiched between the electrostatic adsorption roller 22 and the electrostatic transfer belt 11, and a voltage is applied between the electrostatic transfer belt 11 and the electrostatic adsorption roller 22. By applying the charge, charge is induced in the transfer material S that is a dielectric and the dielectric layer of the electrostatic transfer belt 11, and the transfer material is electrostatically attracted to the outer periphery of the electrostatic transfer belt 11. As a result, the transfer material S is stably adsorbed to the electrostatic transfer belt 11 and conveyed to the most downstream transfer unit.

  While being conveyed in this way, the toner image on each photoconductive drum 1 is sequentially transferred to the transfer material S by an electric field formed between each photoconductive drum 1 and the transfer roller 12.

  The transfer material S on which the toner images of four colors are transferred is separated from the electrostatic transfer belt 11 by the curvature of the belt driving roller 13 and is carried into the fixing unit 20. After the toner image is thermally fixed by the fixing unit 20, the transfer material S is discharged out of the main body by the paper discharge roller pair 23 with the image surface facing down from the paper discharge unit 24.

[Process cartridge configuration]
Next, the process cartridge embodying the present invention will be described in detail with reference to FIGS. FIG. 2 shows a main cross section of the process cartridge 7 containing toner. The yellow, magenta, cyan, and black process cartridges 7a, 7b, 7c, and 7d have the same configuration.

  The process cartridge 7 includes an electrophotographic photosensitive drum 1 that is a photosensitive drum (hereinafter referred to as the photosensitive drum 1), a cleaner unit 50 that includes a charging unit and a cleaning unit, and an electrostatic latent image on the photosensitive drum 1. It is divided into a developing unit 4 having developing means for developing an image.

  In the cleaner unit 50, the photosensitive drum 1 is rotatably attached to the cleaning frame 51 via bearings 73 (73a, 73b) (bearings) and a conductive through shaft member 72. On the periphery of the photosensitive drum 1, a primary charging unit 2 for uniformly charging the photosensitive layer provided on the outer peripheral surface of the photosensitive drum 1, and a developer (on the photosensitive drum 1 after transfer) ( A cleaning blade 60 and a flexible sheet member 80 for removing residual toner) are provided. Further, residual toner (waste toner) removed from the surface of the photosensitive drum 1 by the cleaning blade 60 is sequentially sent to a waste toner chamber 53 provided at the rear of the cleaning frame by the toner feeding mechanism 52. The transfer residual toner on the drum passes through the drum contact portion of the flexible sheet member 80 and reaches the position of the cleaning blade 60. The residual toner removed from the drum by the cleaning blade 60 is removed from the cleaning frame. The contact condition of the flexible sheet member 80 is set so as not to leak out of the body 51.

  The developing unit 4 includes a developing roller 40 that contacts the photosensitive drum 1 and rotates in the arrow Y direction, a toner container 41 that contains toner, and a developing frame 45. The developing roller 40 is rotatably supported by the developing frame body 45 via bearing members 47 and 48, and on the periphery of the developing roller 40, a toner supply roller 43 that rotates in the direction of arrow Z in contact with the developing roller 40. And a developing blade 44 are arranged. Further, a toner transport mechanism 42 for stirring the toner stored in the toner container 41 and transporting it to the toner supply roller 43 is provided.

  The developing unit 4 is entirely connected to the photosensitive drum unit 50 by pins (not shown) around the support shafts 49 provided on bearing members 47 and 48 attached to both ends of the developing unit 4. The suspension structure is supported so as to be swingable. In the state of the process cartridge 7 alone (not attached to the printer main body), the developing unit 4 is always urged by the pressure spring 54 so that the developing roller 40 comes into contact with the photosensitive drum 1 by the rotational moment about the support shaft 49. ing. At the time of development, the toner stored in the toner container 41 is conveyed to the toner supply roller 43 by the toner stirring mechanism 42. The toner supply roller 43 that rotates in the arrow Y direction supplies the toner to the developing roller 40 by rubbing against the developing roller 40 that rotates in the arrow Z direction, and carries the toner on the developing roller 40. The toner carried on the developing roller 40 reaches the developing blade 44 as the developing roller 40 rotates, and the developing blade 44 regulates the toner to form a predetermined toner thin layer, and a desired charged charge amount. Is granted. The toner thinned on the developing roller 40 is conveyed to the developing unit where the photosensitive drum 1 and the developing roller 40 are in contact with each other as the developing roller 40 rotates. The applied DC developing bias adheres to the electrostatic latent image formed on the surface of the photosensitive drum 1 and develops the latent image. The toner remaining on the surface of the developing roller 40 without contributing to the development of the electrostatic latent image is returned to the developing device as the developing roller 40 rotates, and the developing roller is rubbed with the toner supply roller 43. 40 is peeled off and collected. The collected toner is stirred and mixed with the remaining toner by the toner stirring mechanism 42.

  In the contact development method in which development is performed by contacting the photosensitive drum 1 and the developing roller 40 as in the present invention, the photosensitive drum 1 is a rigid body, and the developing roller 40 is a surface layer (contact portion with the photosensitive drum 1). Is preferably an elastic body. As this elastic body, a solid rubber single layer or a solid rubber layer coated with a resin coating in consideration of charge imparting property to toner is used.

[Support and rotation structure of photosensitive drum]
Next, the support structure and drive structure of the photosensitive drum will be described with reference to FIGS. FIG. 3 is a cross-sectional view and a perspective view showing a method for supporting the photosensitive drum.

  The photosensitive drum 1 has a photosensitive drum cylinder 70 provided with a photosensitive layer on the outer peripheral surface, and flanges 71b and 71c are fitted to both ends in the longitudinal direction (axial direction) of the drum cylinder, and at least one flange 71b has a photosensitive member. A contact member 81 that contacts the inner peripheral surface 70a of the drum cylinder 70 is fixed. The flanges 71b and 71c are fixed to the photosensitive drum cylinder 70 by caulking. Further, through holes 71b1 and 71c1 concentric with the photosensitive drum cylinder 70 are provided in the flanges 71b and 71c, and a conductive through shaft member 72 is fitted therein. The conductive penetrating shaft member 72 is made of a metal material such as iron. In this embodiment, the surface of the free-cutting steel bar is plated. At this time, the conductive penetrating shaft member 72 and the contact member 81 are in contact with each other at the contact 81a, and the photosensitive drum cylinder 70 and the conductive penetrating shaft member 72 are electrically connected. The conductive through shaft member 72 extends outward from the length of the photosensitive drum 1, and bearing members 73 a and 73 b that rotatably support the conductive through shaft member 72 are disposed in the extending portions 72 a and 72 b. ing. Since the bearing members 73a and 73b are fixed to the bearing member support portions 51a and 51b of the cleaning frame 51, the photosensitive drum 1 is positioned with respect to the cleaning frame 51 through the bearing members 73a and 73b.

  Next, positioning of the photosensitive drum 1 with respect to the image forming apparatus 100 will be described with reference to FIGS. 5 and 6 are a schematic perspective view and a side view showing the positioning configuration of the process cartridge to the image forming apparatus main body. The outer peripheral surfaces of the bearing members 73 a and 73 b are in a longitudinal (drum axis direction) position where they contact the left plate 74 and the right plate 75 that are the metal plate constituting the image forming apparatus main body 100. The left side plate 74 and the right side plate 75 are provided with abutting surfaces 74a, 74b and 75a, 75b of the bearing members 73a, 73b, and abut the outer peripheral surfaces of the bearing members 73a, 73b. Thus, the photosensitive drum 1 is positioned with respect to the side plate 74 and the side plate 75 via the bearing members 73a and 73b. Next, a method for pressing the photosensitive drum 1 will be described. Here, one end side in the longitudinal direction will be described in detail, but the other end side has the same configuration. Of the outer peripheral surface of the bearing member 73b, a region other than the range facing the abutting surfaces 75a and 75b is covered with a part of the cleaning frame 51 for holding the bearing member 73b. On the other hand, a metal shaft 76 is crimped on the side plate 75 and a torsion coil spring 77 is supported. The arm portion 77 a on one end side of the torsion coil spring 77 is fitted and fixed in a hole 78 provided in the side plate 75. When the process cartridge 7 is not provided, the arm 77b on the other end side is regulated in position in the rotational direction by hooking a bent portion at the tip of the hole 79 provided in the side plate 75. When the process cartridge 7 is mounted, the arm 77b on the other end side urges the pressing portion 51c provided on the cleaning frame 51, whereby the process cartridge 7 and the photosensitive drum 1 are pressed and positioned with respect to the side plate 75. .

  Next, positioning of the process cartridge 7 in the thrust direction (photosensitive drum axial direction) will be described with reference to FIGS. 6, 7, and 8. FIG. 7 is a schematic perspective view showing a positioning configuration of the process cartridge to the image forming apparatus main body, and FIG. 8 is a perspective view showing a thrust pressing configuration of the process cartridge. Here, it is assumed that the side position of the process cartridge 7 is on the side plate 75 side. The side plate 74 is provided with a cartridge thrust pressing member 74c that urges the process cartridge 7 toward the side plate 75. When the process cartridge 7 is mounted on the main body 100, the cartridge thrust pressing member 74c presses the thrust pressing receiving portion 51j provided on the cleaning frame 51, so that the thrust abutting portion provided on the cleaning frame 51 is obtained. 51i is abutted against the cartridge thrust receiving portion 100b provided on the side plate 75, and the position of the process cartridge 7 in the thrust direction with respect to the main body 100 is determined. The cartridge thrust pressing member 74c is made of resin and includes a spring portion 74c1 having one end fixed to the side plate 74 and a pressing portion 74c2. When the process cartridge 7 is mounted on the main body 100, a cleaning frame is formed in the thrust direction by setting the thrust positional relationship such that the pressing portion 74c2 and the thrust pressing receiving portion 51j face each other while the spring portion 74c1 is bent. It is configured to generate a force for urging the body 51 and the process cartridge 7.

  Next, a method for driving the photosensitive drum 1 will be described with reference to FIGS. FIG. 9 is a perspective view showing a photosensitive drum driving method of the process cartridge. One extending portion 72 a of the conductive through shaft member 72 extends through the bearing member 73 a and extends outward from the frame side surface 51 a of the cleaning frame 51. An end face coupling 90 that transmits drive from the image forming apparatus main body 100 is attached to the end of the extending portion 72 a of the conductive through shaft member 72, and rotates integrally with the conductive through shaft member 72. Further, a drive transmission pin 72c to the photosensitive drum 1 is inserted into the conductive penetrating shaft member 72 in a direction orthogonal to the drum axis direction. The drive transmission pin 72c is fitted in a pin groove 71b1 provided in the flange 71b to transmit rotational drive, and performs thrust positioning of the conductive through shaft member 72 and the photosensitive drum 1. The image forming apparatus main body 100 is provided with a drum drive gear 110, and includes a coupling portion 110a for transmitting driving to the end face coupling 90 and a large gear portion 110b for transmitting rotation of the motor 111.

  Next, the thrust direction positioning of the photosensitive drum 1 will be described with reference to FIGS. FIG. 10 is a perspective view showing a thrust retaining structure of the process cartridge. As described above, the cleaning frame 51 and the process cartridge 7 are biased to the side plate 74 side, that is, the non-driving side. Similarly, the photosensitive drum 1 is also urged to the non-driving side by the drum driving gear 110 and the like, and the flange 71c on the non-driving side is abutted against the abutting portion 51z of the cleaning frame 51, so that the position in the thrust direction is increased. Is decided.

[Construction for retaining the conductive through shaft]
The thrust release prevention structure of the photosensitive drum 1 and the conductive through shaft member 72, which is the most characteristic feature of the present invention, will be described. As described above, the photosensitive drum 1 and the conductive penetrating shaft member 72 are biased toward the side plate 74 side, that is, the non-driving side. On the other hand, the photosensitive drum 1 may receive a force on the side plate 73 side, that is, on the driving side due to each process means (cleaning blade, charging roller, developing roller, etc.) acting on the drum surface during rotation or vibration during distribution. . Further, when the drum drive gear 110 is retracted from the end face coupling 90, the photosensitive drum 1 and the conductive through shaft member 72 may receive a force toward the drive side. In such a case, the following configuration is adopted in the present embodiment in order to restrict movement in the thrust direction. The extending portion 72b of the conductive penetrating shaft member 72 (opposite to the extending portion 72a described above) passes through the bearing member 73b and extends outward from the bearing member 73b and the cleaning frame body side surface 51b. A protruding portion 91 larger than the fitting diameter of the bearing member 73b and the conductive through shaft member 72 is provided on the conductive through shaft 72 at a portion outside the bearing member 73b in the extending portion 72b. The protrusion 91 is formed integrally with the conductive penetrating shaft at the non-driving side end (on the side opposite to the end face coupling) of the conductive penetrating shaft of the free-cutting steel rod, and has a predetermined gap between it and the bearing member 73b. It is provided to become. Here, the protrusion 91 may have a shape as shown in FIGS.

(Example 2)
Here, portions that are the same as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

[Construction for retaining the conductive through shaft]
As in the first embodiment, the photosensitive drum 1 and the conductive penetrating shaft member 72 are biased toward the side plate 74 side, that is, the non-driving side. On the other hand, the photosensitive drum 1 may receive a force on the side plate 73 side, that is, on the driving side due to each process means (cleaning blade, charging roller, developing roller, etc.) acting on the drum surface during rotation and vibration during distribution. . Further, when the drum drive gear 110 is retracted from the end face coupling 90, the photosensitive drum 1 and the conductive through shaft member 72 may receive a force toward the drive side. In this case, in order to restrict the movement in the thrust direction, the present embodiment has the following configuration shown in FIG. The extending portion 72b of the conductive penetrating shaft member 72 (opposite to the extending portion 72a described above) passes through the bearing member 73b and extends outward from the bearing member 73b and the cleaning frame body side surface 51b. A cylindrical protrusion 91a larger than the fitting diameter of the bearing member 73b and the conductive through shaft member 72 is provided on the conductive through shaft 72 at a portion outside the bearing member 73b in the extending portion 72b. . The cylindrical protrusion 91a is formed integrally with the conductive penetrating shaft at the non-driving side end (on the opposite side to the end face coupling) of the conductive penetrating shaft of the free-cutting steel rod, and is predetermined between the bearing member 73b. It is provided to be a gap.

  The integral formation includes a case where a cylindrical member which is a separate member is caulked and joined to the conductive penetrating shaft. In addition, it is more effective for space saving in the thrust direction to design the thickness of the cylindrical protrusion in the longitudinal direction so that the strength of the single component and the strength for restricting the thrust direction are guaranteed.

Sectional drawing which shows an example of the multicolor image forming apparatus which concerns on this invention Sectional drawing which shows the process cartridge which concerns on this invention Sectional drawing which shows the drum support method of the process cartridge which concerns on this invention The perspective view which shows the drum support method and drum drive method of the process cartridge which concern on this invention 1 is a schematic perspective view showing a positioning configuration of a process cartridge according to the present invention to an image forming apparatus main body. 1 is a side view showing a positioning configuration of a process cartridge according to the present invention to an image forming apparatus main body. 1 is a schematic perspective view showing a positioning configuration of a process cartridge according to the present invention to an image forming apparatus main body. The perspective view which shows the thrust press structure of the process cartridge which concerns on this invention The perspective view which shows the drum drive method of the process cartridge based on this invention 1 is a perspective view showing a thrust retaining structure in Embodiment 1 of a process cartridge according to the present invention. FIG. The perspective view which shows the other thrust removal prevention structure in Example 1 of the process cartridge based on this invention. FIG. 6 is a perspective view showing a thrust retaining structure in Embodiment 2 of a process cartridge according to the present invention.

Explanation of symbols

1 (1a, 1b, 1c, 1d) Photosensitive drum 2 (2a, 2b, 2c, 2d) Charging device 3 (3a, 3b, 3c, 3d) Scanner unit 4 (4a, 4b, 4c, 4d) Developing device, Developing unit 5 Electrostatic transfer means 6 (6a, 6b, 6c, 6d) Cleaning device 7 (7a, 7b, 7c, 7d) Process cartridge 8 Separating means 11 Electrostatic transfer belt 20 Fixing section 40 (40a, 40b, 40c, 40d) Developing roller 41 Toner container 42 Toner transport mechanism 43 Toner supply roller 44 Developing blade 47, 48 Bearing member 49 Support shaft 51 Cleaning frame 51a, 51b Bearing member supporting portion 51c Pressing portion 51j Thrust pressing receiving portion 51i Thrust abutting portion 51z Abutting portion 52 Toner feeding mechanism 53 Waste toner chamber 54 Pressure spring 60 Leaning blade 70 Photosensitive drum cylinder 71a Pin groove 71b, 71c Flange 71b1, 71c1 Through hole 72 Conductive through shaft member 72a, 72b Extending portion 72c Drive transmission pin 73a, 73b Bearing 74 Left side plate 74a, 74b Abutting surface 74c Cartridge thrust Press member 74c1 Spring part 74c2 Press part 75 Right side plate 75a, 75b Abutting surface 76a, 76b Metal shaft 77a, 77b Torsion coil spring 77b1 Arm part 77b2 Arm part 78a, 78b Hole 79a, 79b Hole 80 on the other end side Flexible Sheet member 81 contact member 81a contact 90 end face coupling 91 protrusion 91a cylindrical protrusion 93 conductive through shaft 93a cylindrical protrusion 100 image forming apparatus main body 100b cartridge thrust receiver 110 drum drive Gear 110a coupling portion 110b large gear portion

Claims (4)

In a process cartridge that can be attached to and detached from the electrophotographic image forming apparatus main body,
An electrophotographic photosensitive drum;
A housing for holding the electrophotographic photosensitive drum;
A through shaft coupled to and supported by the electrophotographic photosensitive drum;
In order to rotatably support the through shaft in the housing, a bearing member provided in the housing that fits in the through shaft;
A coupling member for transmitting the drive from the electrophotographic image forming apparatus main body to the through shaft;
Have
The process cartridge according to claim 1, wherein a protrusion larger than a fitting diameter of the bearing member with the through shaft is provided on the end of the through shaft opposite to the longitudinal direction of the coupling member.   The process cartridge according to claim 1, wherein the protruding portion of the through shaft has a cylindrical shape larger than a fitting diameter between the through shaft and the bearing member. An electrophotographic image forming apparatus that removably supports a process cartridge including at least an electrophotographic photosensitive drum and process means acting on the electrophotographic photosensitive drum,
The process cartridge is
A housing for holding the electrophotographic photosensitive drum;
A through shaft coupled to and supported by the electrophotographic photosensitive drum;
In order to rotatably support the through shaft in the housing, a bearing member fitted to the previous through shaft;
A coupling member for transmitting the drive from the electrophotographic image forming apparatus main body to the through shaft;
Have
Mounting means for enabling removal of the process cartridge in which the through shaft is provided with a protrusion larger than the fitting diameter of the bearing member with the through shaft at the end opposite to the longitudinal direction of the coupling member. An electrophotographic image forming apparatus comprising: 4. The electronic device according to claim 3, further comprising mounting means for making it possible to remove the process cartridge having a cylindrical shape in which the protruding portion of the through shaft is larger than the fitting diameter of the through shaft and the bearing member. Photo image forming apparatus.

Images