JP2004037914A - Process cartridge and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce thrust play due to a gap between a drum and a fall stop part of a drum support shaft. <P>SOLUTION: The drum support shaft is drawn outside a bearing supporting the support shaft about a cartridge frame body and a thrust play stopper is fitted to a shaft end. The thrust play is made small by using a stop ring member for axial insertion as the thrust play stopper. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a process cartridge used for a copying machine, a printer, or the like employing an electrophotographic method, and an image forming apparatus using the same.
[0002]
Here, the electrophotographic image forming apparatus forms an image on a recording medium using an electrophotographic image forming method. Examples of the electrophotographic image forming apparatus include, for example, an electrophotographic copying machine, an electrophotographic printer (for example, a laser beam printer, an LED printer, and the like), a facsimile machine, a word processor, and the like.
[0003]
The process cartridge is a unit in which a charging unit, a developing unit, or a cleaning unit and an electrophotographic photosensitive drum are integrally formed into a cartridge, and this cartridge is detachable from an electrophotographic image forming apparatus main body. 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 so that the cartridge can be attached to and detached from the electrophotographic image forming apparatus main body. Further, it means that at least the developing means and the electrophotographic photosensitive drum are integrally formed into a cartridge so as to be detachable from the main body of the electrophotographic image forming apparatus.
[0004]
[Prior art]
In an electrophotographic image forming apparatus, a photosensitive drum uniformly charged by a charging unit is selectively exposed to form a latent image on the surface of the photosensitive drum. Then, the latent image is visualized by a developer (toner) supplied from a developing unit, transferred to a recording medium, and the image is fixed on the recording medium by heat, pressure, or the like, thereby performing image recording on the recording medium. I have.
[0005]
Further, the developer remaining on the photosensitive drum after the transfer is removed by a cleaning means such as a cleaning blade, and is stored as a residual developer (removed toner) in the cleaning container. The next development can be performed without remaining.
[0006]
Of these parts related to image formation, the photosensitive drum, the charging unit, the developing unit, the cleaning unit, and the like are integrally configured, and a cartridge that is detachably attached to the image forming apparatus main body is put into practical use as a process cartridge. In this case, the user can replace the cartridge by himself. Thus, consumable parts such as the photosensitive drum and the developer can be replaced without maintenance by a service person.
[0007]
The photosensitive drum is constituted by fixing a flange to an end of a cylindrical conductive base having a photosensitive layer on the surface. The photosensitive drum is rotatably supported integrally with a support shaft rotatably supported by a bearing disposed at a predetermined position in the cartridge housing. At one end of the support shaft, there is provided a drive transmission unit for rotating the photosensitive drum in response to the drive from the image forming apparatus main body. Further, the photosensitive drum is urged in one longitudinal direction, and is abutted against a part of the cartridge housing to determine the longitudinal position. On the other hand, a retaining means is provided on the opposite side to the urging direction so that the photosensitive drum and the support shaft do not move more than a predetermined amount in the thrust direction.
[0008]
[Problems to be solved by the invention]
The present invention is a further development of the above-mentioned invention.
[0009]
For example, in the case of a configuration in which a cleaning blade is brought into contact with a photoconductor drum as a cleaning unit, it is desirable to suppress the thrust movement of the photoconductor drum as much as possible, and to prevent an image problem such as a rubbing memory. In addition, it is desirable to reduce the amount of thrust movement of the photosensitive drum, the support shaft, and the drive transmission unit to save space in the thrust direction in the drive transmission unit with the image forming apparatus main body. SUMMARY OF THE INVENTION An object of the present invention is to reduce the thrust play of the photosensitive drum, the support shaft, and the drive transmission means of the process cartridge, thereby preventing image problems such as a rubbing memory and saving the space of the drive transmission unit. .
[0010]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a process cartridge detachably mountable to an electrophotographic image forming apparatus, wherein a photosensitive drum, a process unit acting on the photosensitive drum, and the photosensitive drum and the process unit are held. Housing, flange members provided at both ends of the photoconductor drum, and integrally rotatable with the photoconductor drum via the flange members and rotatably mounted on a bearing portion provided on the housing. A supporting shaft that is supported and extends to the outside of the housing at least at one longitudinal end side, and a thrust retaining member that can be inserted in the axial direction and is provided in the extending portion is a constituent requirement.
[0011]
According to a second aspect of the present invention, there is provided a process cartridge according to the first aspect, wherein the thrust retaining member is a metal ring-shaped elastic member.
[0012]
According to a third aspect of the present invention, in the process cartridge according to the first or second aspect, the thrust retaining member is mounted at a predetermined gap based on the housing or the bearing. It is a matter.
[0013]
According to a fourth aspect of the present invention, there is provided a process cartridge according to the first or second aspect, wherein the thrust retaining member is mounted by abutting against the bearing portion.
[0014]
According to a fifth aspect of the present invention, in the process cartridge according to any one of the first to third aspects, the supporting shaft is a through shaft extending to the outside of the housing on both sides in the longitudinal direction, and is opposite to the one end side. It has an end face coupling for transmitting the rotation drive of the photosensitive drum on the side.
[0015]
According to a sixth aspect of the present invention, in the process cartridge according to any one of the first to third aspects, the support shaft is formed integrally with the flange member, and extends to the outside of the housing on both sides in the longitudinal direction. An end surface coupling for rotating the photosensitive drum is provided on a side opposite to the one end side.
[0016]
According to a seventh aspect of the present invention, there is provided an image forming apparatus in which a process cartridge is detachably mountable, wherein a photosensitive drum, a process unit acting on the photosensitive drum, a photosensitive drum, and a housing holding the process unit. A support shaft that rotates integrally with the photosensitive drum and is rotatably supported by a bearing portion provided in the housing, and extends to the outside of the housing at least at one longitudinal end. An axially insertable thrust retaining member disposed in the extending portion, mounting means for mounting the process cartridge having the above configuration, and driving means for transmitting drive to the process cartridge having the above configuration. And
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
(1st Embodiment)
Hereinafter, an embodiment of a multicolor image forming apparatus according to the present invention will be described in detail with reference to the drawings.
[0018]
[Overall Configuration of Multicolor Image Forming Apparatus]
First, the overall configuration of the multicolor image forming apparatus will be outlined with reference to FIG. FIG. 1 is a longitudinal sectional view showing the overall configuration of a full-color laser beam printer 100 which is one mode of a multicolor image forming apparatus.
[0019]
The multicolor image forming apparatus 100 shown in FIG. 1 includes four photosensitive drums 1a, 1b, 1c, 1d arranged in a vertical direction. The photosensitive drum 1 is driven to rotate counterclockwise in FIG. 1 by a driving unit (not shown). A charging device 2 (2a, 2b, 2c, 2d) for uniformly charging the surface of the photoconductor drum 1 in order according to the rotation direction around the photoconductor drum 1, irradiating a laser beam based on image information to the photoconductor 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 attaching toner to the electrostatic latent image and developing it as a toner image ), An electrostatic transfer device 5 for transferring the toner image on the photosensitive drum 1 to the transfer material S, and a cleaning device 6 (6a, 6b, 6c, 6b, 6c, 6c) for removing transfer residual toner remaining on the surface of the photosensitive drum 1 after the transfer. 6d) and so on.
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 in order.
[0020]
The photosensitive drum 1 is configured by providing a photosensitive layer on the outer peripheral surface of an aluminum cylinder having a diameter of, for example, 30 mm. The photosensitive drum 1 is rotatably supported at both ends by a support member, and is driven to rotate counterclockwise by transmitting a driving force from a driving motor (not shown) to one end. You.
[0021]
As the charging device 2, a charging device of 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 a charging bias voltage is applied to the roller to make the surface of the photosensitive drum 1 uniform. Is charged. In the present embodiment, since the reversal developing system is used, the surface of the photosensitive drum 1 is charged to a negative polarity.
[0022]
The scanner unit 3 is arranged in a substantially horizontal direction of the photosensitive drum 1, and a polygon mirror 9 (9a, 9a, 9a, 9a, 9b) which rotates image light corresponding to an image signal by a laser diode (not shown) at a high speed by a scanner motor (not shown). 9b, 9c, 9d). The image light reflected by the polygon mirror 9 selectively exposes the surface of the charged photosensitive drum 1 via the imaging lens 10 (10a, 10b, 10c, 10d) to form an electrostatic latent image. Make up.
[0023]
The developing device 4 includes toner containers 41 (41a, 41b, 41c, 41d) containing toners of yellow, magenta, cyan, and black, respectively. The toner is applied to the outer circumference of the developing roller 40 which rotates clockwise in the figure by a developing blade 44 pressed against the outer circumference of the toner supply roller 43 and the developing roller 40 which rotate clockwise in the figure, and charges the toner. Give.
[0024]
By applying a developing bias to the developing roller 40 facing the photosensitive drum 1 on which the latent image is formed, toner development is performed on the photosensitive drum 1 in accordance with the latent image.
[0025]
The electrostatic transfer device 5 is provided with an electrostatic transport belt 11 that circulates and moves so as to face all the photosensitive drums 1a, 1b, 1c, and 1d. As the electrostatic transport belt 11, a resin film or a multilayer film-like member having a resin layer provided on a rubber base layer is used. The electrostatic transport belt 11 is stretched around a drive roller 13, driven rollers 14a and 14b, and a tension roller 15. The electrostatic transport belt 11 electrostatically attracts the transfer material S to the outer peripheral surface on the left side in FIG. The transfer material S is circulated so as to come into contact therewith. As a result, the transfer material S is transported to the transfer position by the electrostatic transfer belt 11, and the toner image on the photosensitive drum 1 is transferred.
[0026]
Transfer rollers 12 (12a, 12b, 12c, 12d) are arranged side by side at positions facing 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 these transfer rollers 12 during transfer, and positive polarity charges are applied to the transfer material S via the electrostatic transfer belt 11. Due to the electric field generated at this time, a negative polarity toner image on the photosensitive drum 1 is transferred to the transfer material S in contact with the photosensitive drum 1.
[0027]
The paper feed unit 16 feeds and conveys the transfer material S to the image forming unit. A plurality of transfer materials S are stored in a 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 materials S in the paper feed cassette 17 one by one, and Stops once, stops once, forms a loop, and is fed to the electrostatic transfer belt 11 by the registration roller pair 19 by synchronizing the rotation of the electrostatic transfer belt 11 and the image writing position. .
[0028]
The fixing unit 20 fixes the toner images of a plurality of colors transferred to the transfer material S. The fixing unit 20 includes a rotating heating roller 21a, and a pressing roller 21b that presses against the heating roller 21a to apply heat and pressure to the transfer material S. Consists of
[0029]
That is, the transfer material S on which the toner image on the photosensitive drum 1 has been 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. Thus, the toner images of a plurality of colors are fixed on the surface of the transfer material S.
[0030]
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 rotate 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 applies a uniform charge to the peripheral surface of the photosensitive drum 1, and the scanner unit 3 performs exposure on the peripheral surface of the photosensitive drum 1 according to an image signal, and An electrostatic latent image is formed on the peripheral surface. The developing roller 40 in the developing device 4 transfers toner to a low potential portion of the electrostatic latent image to form (develop) a toner image on the peripheral surface of the photosensitive drum 1.
[0031]
At the timing when the leading end of the toner image on the peripheral surface of the photosensitive drum 1 at the most upstream position is rotated and conveyed to a point facing the electrostatic transfer belt 11, the printing start position of the transfer material S coincides with the point. Then, the registration roller pair 19 starts rotating and feeds 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 attraction roller 22 and the electrostatic transfer belt 11, and a voltage is applied between the electrostatic transfer belt 11 and the electrostatic attraction roller 22. By applying the charge, electric charges are induced in the transfer material S which 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. Thereby, the transfer material S is stably adsorbed on the electrostatic transfer belt 11 and is conveyed to the most downstream transfer unit.
[0032]
While being conveyed in this manner, the toner image on each photosensitive drum 1 is sequentially transferred onto the transfer material S by an electric field formed between each photosensitive drum 1 and the transfer roller 12.
The transfer material S onto which the four color toner images have been transferred is separated from the electrostatic transfer belt 11 by the curvature of the belt drive roller 13 and is carried into the fixing unit 20. After the toner image is heat-fixed by the fixing unit 20, the transfer material S is discharged from the main body by the discharge roller pair 23 with the image surface facing down from the discharge unit 24.
[0033]
[Configuration of process cartridge]
Next, a process cartridge embodying the present invention will be described in detail with reference to FIG. 2 and 3 show a main cross section and a perspective view of the process cartridge 7 containing the toner. FIG. 6 shows a schematic frame structure of the image forming apparatus main body. The yellow, magenta, cyan, and black process cartridges 7a, 7b, 7c, and 7d have the same configuration.
[0034]
The process cartridge 7 includes an electrophotographic photosensitive drum 1 (hereinafter, referred to as a photosensitive drum 1) as a photosensitive drum, a cleaner unit 50 including a charging unit and a cleaning unit, and an electrostatic latent drum on the photosensitive drum 1. It is divided into a developing unit 4 having a developing means for developing an image.
[0035]
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 shaft member 72. Primary charging means 2 for uniformly charging the photosensitive layer provided on the outer peripheral surface of the photoconductor drum 1 is provided on the circumference of the photoconductor drum 1, and the developer remaining on the photoconductor drum 1 after the transfer ( A cleaning blade 60 for removing residual toner) and a flexible sheet member 80 are provided. Further, the 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 behind the cleaning frame by a toner feeding mechanism 52. The transfer residual toner on the drum reaches the position of the cleaning blade 60 through the drum contact portion of the flexible sheet member 80, but the residual toner removed from the drum by the cleaning blade 60 is removed by the cleaning frame. The contact condition of the flexible sheet member 80 is set so as not to leak out of the body 51.
[0036]
The developing unit 4 includes a developing roller 40 that contacts the photosensitive drum 1 and rotates in the direction of arrow Y, a toner container 41 containing toner, and a developing frame 45. The developing roller 40 is rotatably supported by a developing frame 45 via a bearing member. On the periphery of the developing roller 40, a toner supply roller 43 and a developing blade which are in contact with the developing roller 40 and rotate in the direction of arrow Z. 44 are respectively arranged. Further, a toner transport mechanism 42 for stirring the stored toner and transporting the toner to the toner supply roller 43 is provided in the toner container 41.
[0037]
The entire developing unit 4 is swingable with respect to the photosensitive drum unit 50 by a pin 49 a around a support shaft 49 provided on bearing members 47 and 48 attached to both ends of the developing unit 4. It has a suspended structure supported by. When the process cartridge 7 is alone (not mounted on the printer main body), the developing unit 4 is constantly urged by the pressure spring 54 so that the developing roller 40 comes into contact with the photosensitive drum 1 by a rotational moment about the support shaft 49. ing. During development, the toner stored in the toner container 41 is transported to the toner supply roller 43 by the toner stirring mechanism 42. The toner supply roller 43 rotating in the direction of the arrow Y supplies the toner to the developing roller 40 by rubbing against the developing roller 40 rotating in the direction of the arrow Z, and carries the toner on the developing roller 40. The toner carried on the developing roller 40 reaches the developing blade 44 with the rotation of the developing roller 40, and the developing blade 44 regulates the toner to form a predetermined toner thin layer, and a desired amount of charge Is given. As the developing roller 40 rotates, 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. 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 into the developing device with the rotation of the developing roller 40, and is rubbed with the toner supply roller 43 by the developing roller. Peeled from 40 and collected. The collected toner is stirred and mixed with the remaining toner by the toner stirring mechanism 42.
[0038]
In the contact developing method in which the photosensitive drum 1 and the developing roller 40 come into contact with each other to perform development as in the present invention, the photosensitive drum 1 is made rigid and the developing roller 40 is a surface layer (a contact portion with the photosensitive drum 1). Is preferably an elastic body. As the elastic body, a solid rubber single layer or a solid rubber layer coated with a resin in consideration of the charging property to the toner is used.
[0039]
[Photoconductor drum support and rotation configuration]
Next, a supporting structure and a driving structure of the photosensitive drum will be described with reference to FIGS.
[0040]
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 at both ends in the longitudinal direction (axial direction) of the drum cylinder. 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 the conductive shaft member 72 is fitted therein. The conductive shaft member 72 is made of a metal material such as iron. In the present embodiment, the surface of the free-cutting steel bar is plated. At this time, the conductive shaft member 72 and the contact member 81 are in contact with each other at the contact 81a, and the photoconductive drum cylinder 70 and the conductive shaft member 72 are electrically connected. The conductive shaft member 72 extends outward from the length of the photosensitive drum 1, and bearing members 73a and 73b that rotatably support the conductive shaft member 72 are disposed on the extending portions 72a and 72b. . 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 via the bearing members 73a and 73b.
[0041]
Next, positioning of the photosensitive drum 1 with respect to the image forming apparatus 100 will be described with reference to FIGS. The outer peripheral surfaces of the bearing members 73a and 73b are located at longitudinal positions (in the drum axis direction) in contact with the left and right plates 74 and 75 made of sheet metal 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 against the outer peripheral surfaces of the bearing members 73a, 73b. Thus, the photosensitive drum 1 is positioned with respect to the side plates 74 and 75 via the bearing members 73a and 73b. Next, a method of pressing the photosensitive drum 1 will be described. Here, one end in the longitudinal direction will be described in detail, but the other end has the same configuration. In the outer peripheral surface of the bearing member 73b, a region other than a region facing the abutting surfaces 75a and 75b is covered with a part of the cleaning frame body 51 for holding the bearing member 73b. On the other hand, a metal shaft 76 is crimped to the side plate 75, and a torsion coil spring 77 is supported. An 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 has a bent portion at the tip hooked on a hole 79 provided in the side plate 75 to regulate the position in the rotation direction. When the process cartridge 7 is mounted, the arm 77 b on the other end urges the pressing portion 51 c provided on the cleaning frame 51, so that the process cartridge 7 and the photosensitive drum 1 are pressed and positioned against the side plate 75. .
[0042]
Next, the positioning of the process cartridge 7 in the thrust direction (axial direction of the photosensitive drum) will be described with reference to FIGS. Here, it is assumed that there is a thrust direction position reference of the process cartridge 7 on the side plate 75 side. The side plate 74 is provided with a cartridge thrust pressing member 74c for urging 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 74 c presses a thrust pressing receiving portion 51 j provided on the cleaning frame 51, thereby causing a thrust abutting portion provided on the cleaning frame 51. 51i is abutted against a 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, the thrust position is such that the pressing portion 74c2 and the thrust pressing receiving portion 51j face each other in a state where the spring portion 74c1 is bent, so that the cleaning frame is moved in the thrust direction. It is configured to generate a force for urging the body 51 and the process cartridge 7.
[0043]
Next, a method of driving the photosensitive drum 1 will be described with reference to FIGS. One extending portion 72a of the conductive shaft member 72 extends outside the frame side surface 51a of the cleaning frame 51 through the bearing member 73a. An end face coupling 90 for transmitting the drive from the image forming apparatus main body 100 is attached to the end of the extending portion 72 a of the conductive shaft member 72, and rotates integrally with the conductive shaft member 72. A drive transmission pin 72c to the photosensitive drum 1 is inserted into the conductive shaft member 72 in a direction orthogonal to the axial direction of the drum. The drive transmission pin 72c fits into a pin groove 71b1 provided in the flange 71b to transmit rotational drive, and also performs thrust positioning between the conductive 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 drive to the end face coupling 90 and a large gear portion 110b for transmitting rotation of the motor 111.
Next, positioning of the photosensitive drum 1 in the thrust direction will be described with reference to FIGS. As described above, the cleaning frame 51 and the process cartridge 7 are urged toward the side plate 74, that is, the non-drive side. Similarly, the photosensitive drum 1 is urged to the non-drive side by the drum drive gear 110, and the flange 71c on the non-drive side is abutted against the abutment portion 51z of the cleaning frame 51, and the position in the thrust direction is changed. Decided.
[0044]
Next, a structure for preventing the thrust of the photosensitive drum 1 and the conductive shaft member 72 from coming off will be described. As described above, the photosensitive drum 1 and the conductive shaft member 72 are urged toward the side plate 74, that is, the non-driving side. On the other hand, the photosensitive drum 1 may receive a biasing force toward the side plate 73, that is, the driving side, by each process means (cleaning blade, charging roller, developing roller, etc.) acting on the drum surface during rotation. Further, even when the drum drive gear 110 retreats from the end face coupling 90, the photosensitive drum 1 and the conductive shaft member 72 may receive a force on the drive side. The extending portion 72b of the conductive shaft member 72 (the side opposite to the above-described extending portion 72a) extends outside the bearing member 73b and the cleaning frame side surface 51b through the bearing member 73b. A ring-shaped retaining member 91 is attached to a portion of the extending portion 72b outside the bearing member 73b. The retaining member 91 is positioned so as to have a predetermined gap between the retaining member 91 and the bearing member 73b. The retaining member 91 in the present embodiment is made of metal such as stainless steel, and has a claw portion 91b provided inside the retaining portion 91a. The retaining member 91 is inserted in the axial direction while the claw portion 91b abuts on the outer peripheral surface of the conductive shaft member 72 and bends. In order to minimize the gap between the retaining member 91 and the bearing member 73b, the thrust position of the retaining member 91 is determined on the basis of the end surface of the bearing member 73b to reduce the accumulation of tolerance. Further, the retaining member 91 may be attached by abutting against the bearing member 73b. In this case, the thrust play between the photosensitive drum 1 and the conductive shaft member 72 can be eliminated, but since the stopper member 91 and the bearing member 73b that rotate integrally with the conductive shaft member 72 slide, the stopper member A washer or the like may be interposed between the bearing 91 and the bearing member 73b.
[0045]
(Second embodiment)
Here, parts that are the same as in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
[0046]
[Configuration of photoconductor drum]
The photosensitive drum 1 has a photosensitive drum cylinder 70 provided with a photosensitive layer on the outer peripheral surface, and flanges 92b and 92c are fitted at both ends in the longitudinal direction (axial direction) of the drum cylinder. A contact member 81 that contacts the inner peripheral surface 70a of the drum cylinder 70 is fixed. The flanges 92b and 92c are fixed to the photosensitive drum cylinder 1 by fixing means such as caulking or bonding. Conductive support shafts 93b and 93c concentric with the photosensitive drum cylinder 70 are attached to the flanges 92b and 92c, and extend outward from the end surface of the photosensitive drum 1 in the thrust direction. The flanges 92b and 92c in the present embodiment are made of resin, and the conductive support shaft is attached by insert molding or the like. The extending portion 93b1 of the conductive support shaft 93b extends through the bearing member 73a to extend outside the frame side surface 51a of the cleaning frame 51, and the end portion 93b2 of the extending portion 93b1 extends from the image forming apparatus main body 100. An end face coupling 90 for transmitting drive is provided. On the other hand, the conductive support shaft 93c on the opposite side, that is, the non-drive side also extends through the bearing member 73c and extends outward from the cleaning frame body side surface 51b to form an extended portion 93c1. A ring-shaped retaining member 91 is attached to a portion of the extending portion 93c1 outside the bearing member 73c, and is positioned so as to have a predetermined gap between the extending portion 93c1 and the bearing member 73c.
[0047]
【The invention's effect】
As described above, in the process cartridge in which the photosensitive drum and the support shaft are integrally rotatably supported by the cleaning frame and the support shaft extends longitudinally outward from the bearing member, one end of the support shaft is provided. On the other side, there is an end face coupling for transmitting the drive from the image forming apparatus main body, and on the other end side, a ring-shaped thrust retaining member is inserted longitudinally outside the bearing member. By making the thrust retaining member a metal toothed retaining ring that can be inserted in the axial direction, the thrust position can be determined based on the end surface of the bearing member, and the gap between the bearing member and the thrust retaining member can be determined. The generated thrust play can be minimized. Thus, the rubbing memory between the photosensitive drum and the process means that contacts the photosensitive drum can be reduced, and the space for the drive transmission unit can be saved.
[Brief description of the drawings]
FIG. 1 is a sectional view showing an example of a multicolor image forming apparatus according to the present invention.
FIG. 2 is a sectional view showing a process cartridge according to the present invention.
FIG. 3 is a sectional view showing a method for supporting a drum of a process cartridge according to the present invention.
FIG. 4 is a perspective view illustrating a method for supporting a drum of the process cartridge and a method for driving the drum according to the present invention.
FIG. 5 is a schematic perspective view showing a configuration for positioning a process cartridge according to the present invention with respect to the image forming apparatus main body.
FIG. 6 is a side view showing a configuration for positioning a process cartridge according to the present invention with respect to an image forming apparatus main body.
FIG. 7 is a schematic perspective view showing a configuration for positioning a process cartridge according to the present invention with respect to an image forming apparatus main body.
FIG. 8 is a perspective view illustrating a thrust pressing configuration of the process cartridge according to the present invention.
FIG. 9 is a perspective view showing a method for driving the drum of the process cartridge according to the present invention.
FIG. 10 is a perspective view showing a thrust retaining structure of the process cartridge according to the present invention.
FIG. 11 is a cross-sectional view illustrating a drum supporting method in a second embodiment of the process cartridge according to the present invention.
[Explanation of symbols]
1 (1a, 1b, 1c, 1d) Photoconductor 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 Separation means
11 Electrostatic transfer belt
20 Fixing unit
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 support
51c pressing part
51j Thrust pressure receiving part
51i thrust abutment
51z butting part
52 Toner feed mechanism
53 Waste toner chamber
54 Pressure spring
60 Cleaning blade
70 Photosensitive drum cylinder
70a Inner circumference
71b, 71c, flange
71b1, 71c1 Through hole
71b1 Pin groove
80 Flexible sheet member
81 Contact material
81a contact
72 Conductive shaft member
72a, 72b stretching section
72c Drive transmission pin
73a, 73b bearing
74 Left side plate
74a, 74b butting surface
74c Cartridge thrust pressing member
74c1 spring part
74c2 pressing part
75 Right side plate
75a, 75b butting surface
76 Metal shaft
77 Torsion coil spring
77a arm
77b Arm on the other end
78 holes
79 holes
80 Flexible sheet member
90 End face coupling
91 Retaining member
91a Retaining part
91b claw
92b, 92c flange
93b, 93c conductive support shaft
93b1, 93c1 stretching part
93b2 end
100 Image Forming Apparatus Main Body
100a Cartridge thrust receiver
110 Drum drive gear
110a Coupling part
110b Large gear

Claims (7)

The components of a process cartridge that can be attached to and detached from the electrophotographic image forming apparatus are as follows: photosensitive drum process means acting on the photosensitive drum; a photosensitive drum and a housing for holding the process means; The flange member is disposed integrally with the photosensitive drum via the flange member, and is rotatably supported by a bearing provided on the housing, and at least one longitudinal end of the housing. An axially insertable thrust retaining member disposed in the extending portion of the support shaft extending outside the body. The process cartridge according to claim 1,
The thrust retaining member is a metal ring-shaped elastic member. The process cartridge according to claim 1, wherein
The thrust retaining member is mounted at a predetermined gap based on the housing or the bearing. The process cartridge according to claim 1, wherein
The thrust retaining member is mounted so as to abut the bearing portion. The process cartridge according to claim 1, wherein
The support shaft is a penetrating shaft extending to the outside of the housing on both sides in the longitudinal direction, and has an end face coupling for transmitting the rotation drive of the photosensitive drum on the side opposite to the one end. The process cartridge according to claim 1, wherein
The support shaft is formed integrally with the flange member, extends to the outside of the housing on both sides in the longitudinal direction, and has an end face coupling on the opposite side to the one end side for rotationally driving the photosensitive drum. The configuration requirements of the image forming apparatus to which the process cartridge can be attached and detached are as follows: photosensitive drum process means acting on the photosensitive drum; the photosensitive drum; and a housing holding the process means. A support shaft that is rotatably supported by a bearing portion provided in the housing and is rotatable at least at one longitudinal end to the outside of the housing. Thrust retaining member that can be inserted into the cartridge mounting means for mounting the process cartridge having the above-described configuration; and driving means for transmitting drive to the process cartridge having the above-described configuration.

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