JP2003131543A - Process cartridge and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the accuracy in the positioning of an electrifying member by disposing the electrifying member on one side in the longitudinal thrust direction in a process cartridge. SOLUTION: An inclined face is formed on an end of the electrifying member. The inclined face is held by a support member, thereby supporting an electrifying roller within the frame body of the process cartridge. The electrifying member moves in the longitudinal thrust direction by the urging force of a pressing spring, the holding force of the support member, and the component force of pressing force acting on the inclined face. The movement of the electrifying member is completed when the process cartridge contacts the contact portions of the electrifying member. Thus, in the longitudinal thrust direction, the electrifying member is positioned to the process cartridge.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process cartridge and an electrophotographic image forming apparatus.

The image forming apparatus here is an electrophotographic image forming apparatus, which 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, laser printer, LED printer, etc.), a facsimile machine, and a word processor.

A process cartridge is a cartridge in which at least an electrophotographic photosensitive member, a charging unit, a developing unit and a cleaning unit are integrally formed, and the cartridge can be attached to and detached from the main body of the image forming apparatus. .

Further, at least the electrophotographic photosensitive member and the charging means, and at least one of the developing means and the cleaning means are integrally made into a cartridge so as to be attachable to and detachable from the main body of the image forming apparatus.

Further, at least the electrophotographic photosensitive member and the charging means are integrally made into a cartridge so that it can be attached to and detached from the main body of the image forming apparatus.

[0006]

2. Description of the Related Art Conventionally, a transfer type electrophotographic apparatus generally has the following means structure and image forming process. That is, an electrophotographic photosensitive member such as selenium, cadmium sulfide, zinc oxide, amorphous silicon, or an organic photoconductor, which is generally a rotating drum type as an image bearing member, is used, and the surface of the photosensitive member is charged with a predetermined positive charge. · Evenly charged to a potential, and the exposed photoreceptor surface is imagewise exposed by image exposure means to form an electrostatic latent image corresponding to the exposed image, and developing means develops toner on the electrostatic latent image. Are attached to develop the toner image, and the toner image is transferred. The material to which the toner image has been transferred is subjected to a fixing process by the fixing means and discharged as an image-formed product (copy, print). Further, after the transfer of the toner image onto the transfer material, the rotating photoconductor is subjected to removal of the transfer residual toner by a cleaning means (cleaner) and is repeatedly used for image formation.

As a charging means for a photosensitive member as an image bearing member which is a member to be charged, a "corona charging type" charging means using a corona discharger has been generally used, but a fur brush type (fur The contact charging method in which various types such as brush members) are used can lower the applied voltage compared to the corona charging method, and the generation amount of corona products such as ozone is significantly reduced. Recently, the “contact charging method (direct charging method)” is used because it has advantages such as high power efficiency and has advantages such as lower ozone and lower power than the corona charging method.

In the contact charging system, a corona charging is not used, and a conductive member whose resistance value is adjusted is provided as a charging member (charging member) in contact with a photosensitive member as a member to be charged. By applying a voltage (charging bias), the surface of the photoconductor is charged to a predetermined polarity and potential.

As the charging member, various types such as a conductive elastic roller type (charging roller), a conductive elastic blade type (charging blade), a magnetic brush type (magnetic brush), a fur brush type (fur brush member), etc. However, compared with the corona charging method, the contact charging method can lower the applied voltage, significantly reduce the generation amount of corona products such as ozone, have good electrical efficiency, etc. There are advantages.

Among the above-mentioned contact charging methods, the method of supporting a charging member, such as a conductive elastic roller type, which requires a rotating operation in the image forming state, is a supporting method provided at both longitudinal ends of the cartridge frame. The charging member is rotatably supported in the cartridge frame by the member holding both ends of the cored bar which penetrates the center of the elastic member. Further, the supporting member is urged in the rotation axis direction of the electrophotographic photosensitive member by the urging member arranged between the supporting member and the cartridge frame. Therefore, the charging member supported by the supporting member comes into contact with the electrophotographic photosensitive member to form an electric circuit. Also,
In the case of the conductive elastic roller type, it does not have a positive driving means and is configured to be driven to rotate by the rotation of the electrophotographic photosensitive member.

[0011]

However, in the above-mentioned prior art, the component parts such as the cartridge frame, the supporting member, and the charging member have manufacturing dimensional variations. Therefore, the charging member is supported by the cartridge frame. In this state, there is always play in the longitudinal thrust direction. Further, in order for the charging member to stably rotate following the electrophotographic photosensitive member, it is necessary to avoid increasing the sliding resistance between the supporting member and the core metal significantly. Directional position cannot be regulated.

In order to always stably charge the image area on the surface of the electrophotographic photosensitive member under such a condition, the charging member can cover the image area regardless of the position in the longitudinal thrust direction of the charging member. Dimensional tolerances for components must be set. However, since each component has a limit of dimensional tolerance in manufacturing, in order to realize the above, it is inevitable to increase the size of the device in the longitudinal thrust direction. This is a strict constraint for miniaturization design.

It is also possible to control the play in the longitudinal thrust direction of the charging means by light pressure using an elastic body such as a metal spring, but it is necessary to add an elastic member as a separate body.
This causes a significant cost increase.

The present invention has been made by paying attention to the above-mentioned problems, and the process cartridge in which the longitudinal position of the charging means is stable and the space can be saved in the longitudinal direction without significantly increasing the cost. Another object of the present invention is to provide an image forming apparatus.

[0015]

In order to achieve the above object, a process cartridge according to the present invention has a structure (1) to
In (9), the configurations of the image forming apparatus are shown in (10) to (18), respectively.

(1) A process cartridge which comprises at least an electrophotographic photosensitive member, a charging unit for charging the electrophotographic photosensitive member, and a supporting unit for supporting the charging unit, and which is detachable from the main body of the image forming apparatus. A process cartridge, wherein an inclined surface portion is provided at an end portion of the charging means, and the supporting means supports the charging means by holding the inclined surface portion.

(2) A longitudinal direction positioning portion for positioning the charging member in the longitudinal direction is provided at one end side in the longitudinal direction of the process cartridge, and the inclined surface portion is provided at the end portion of the charging means at the other end side. The process cartridge according to (1) above, wherein the process cartridge is provided.

(3) It is characterized in that the longitudinal direction positioning portion is arranged at one end side in the longitudinal direction of the process cartridge, and the inclined surface portion is arranged at the end portion of the charging means at the same one end side. The process cartridge according to (1) above.

(4) The longitudinal positioning portion is disposed on one end side in the longitudinal direction of the process cartridge, and the inclined surfaces are disposed on both end portions of the charging means on one end side and the other end side. The process cartridge according to (1) above, which is characterized in that

(5) The charging means is a charging roller comprising at least a metal shaft and an elastic body for contact-charging the electrophotographic photosensitive member, and the inclined surface portion is provided at the other end of the metal shaft. The inclined surface of the inclined surface portion has a shape in which the shaft diameter becomes smaller toward the other end side end surface of the metal shaft of the charging roller, and the support member can rotate the charging roller by holding the inclined surface portion. The process cartridge according to (2) above, which is a bearing member that supports the process cartridge.

(6) The charging means is a charging roller comprising at least a metal shaft and an elastic body for contact-charging the electrophotographic photosensitive member, the inclined surface portion is disposed at one end of the metal shaft, and the inclined surface portion is provided. Has a shape in which the shaft diameter increases toward the one end side end surface of the metal shaft of the charging roller, and the supporting member rotatably supports the charging roller by holding the inclined surface portion. The process cartridge according to (3) above, which is a member.

(7) The charging means is a charging roller comprising at least a metal shaft and an elastic body for contact-charging the electrophotographic photosensitive member, and inclined surfaces are provided at both ends of the metal shaft, and the other end is provided. The inclined surface of the inclined surface portion on one side has a shape in which the shaft diameter becomes smaller toward the other end side end surface of the metal shaft of the charging roller, and the inclined surface of the inclined surface portion on the one end side is the metal shaft of the charging roller. (4) has a shape in which the shaft diameter becomes thicker toward the one end side end surface, and the supporting member is a bearing member that rotatably supports the charging roller by holding the inclined surface portion. ) The process cartridge described.

(8) The process cartridge according to any one of the above (5) to (7), wherein the bearing member is made of an elastic restoration body.

(9) The process cartridge according to any one of (5) to (8), wherein the bearing member is made of a conductive member.

(10) At least (a) an electrophotographic photosensitive member, (b) charging means for charging the electrophotographic photosensitive member and having an inclined surface portion at an end thereof, and (c) the inclined surface portion. An image forming apparatus, wherein a process cartridge including a support unit that supports the charging unit by holding the process cartridge is detachable.

(11) In the process cartridge, (a) a longitudinal direction positioning portion for longitudinally positioning the charging member at one end side in the longitudinal direction, and (b) a longitudinal direction end portion at the other end side in the longitudinal direction. The image forming apparatus according to (10) above, wherein a process cartridge including the charging unit having an inclined surface portion is detachable.

(12) In the process cartridge, (a) a longitudinal direction positioning portion for positioning the charging member in the longitudinal direction at one end side in the longitudinal direction, and (b) the inclined surface portion at the end portion at the same one end side. The image forming apparatus according to (10) above, wherein the process cartridge including the charging unit is detachably attachable.

(13) In the process cartridge, (a) a longitudinal direction positioning portion for positioning the charging member in the longitudinal direction at one end side in the longitudinal direction, and (b) the longitudinal positioning portions at both ends on one end side and the other end side. The image forming apparatus according to (10) above, wherein a process cartridge including the charging unit having an inclined surface portion is detachable.

(14) In the process cartridge, (a) a charging roller composed of at least a metal shaft and an elastic body for contact-charging the electrophotographic photosensitive member, and (b) a metal shaft end portion of the charging roller, and the other end side. The inclined surface portion (c) having an inclined surface having a shape in which the shaft diameter becomes smaller toward the end surface (c) A process cartridge including a bearing member that rotatably supports the charging roller by holding the inclined surface portion is detachable. Above (11) characterized in that
The image forming apparatus described.

(15) In the process cartridge, (a) a charging roller composed of at least a metal shaft and an elastic body for contact-charging the electrophotographic photosensitive member, and (b) a metal shaft end portion of the charging roller, which has an end surface on one end side. The inclined surface portion (c) having an inclined surface having a shape in which the shaft diameter becomes thicker toward (1). A process cartridge including a bearing member that rotatably supports the charging roller by holding the inclined surface portion is removable. The image forming apparatus according to (12) above.

(16) In the process cartridge, (a) a charging roller composed of at least a metal shaft and an elastic body for contact-charging the electrophotographic photosensitive member, and (b) both ends of the metal shaft of the charging roller, and the other end. The inclined surface portion (c) has an inclined surface having a shape in which the shaft diameter becomes smaller toward the end surface on the other end side, and the one end side has an inclined surface in which the shaft diameter becomes thicker toward the end surface on the one end side. The image forming apparatus according to (13) above, wherein a process cartridge including a bearing member that rotatably supports the charging roller by holding it is removable.

(17) The image forming apparatus as described in any one of (14) to (16) above, wherein the process cartridge provided with the bearing member made of an elastic restoration body is removable.

(18) The image forming apparatus as described in any of (14) to (16) above, wherein the process cartridge provided with the bearing member made of a conductive member is removable.

[0034]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

In the following description, the longitudinal direction of the process cartridge is a direction (a direction substantially orthogonal to) intersecting with the direction in which the process cartridge is attached to and detached from the apparatus main body, parallel to the surface of the recording medium, and recording. It is a direction intersecting (substantially orthogonal) with the transport direction of the medium. The left and right of the process cartridge are right or left when viewed from above according to the recording medium conveyance direction. Further, the upper surface of the process cartridge is a surface located above when the process cartridge is mounted in the apparatus main body, and the lower surface is a surface located below.

[0036]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be specifically described with reference to the drawings.

The process cartridge and the electrophotographic image forming apparatus to which the process cartridge is attachable / detachable will be specifically described with reference to FIGS. 1 and 2. 1 is a sectional view showing an outline of an electrophotographic image forming apparatus equipped with a process cartridge, and FIG. 2 is a sectional view showing an outline configuration of the process cartridge.

Here, as the order of description, the overall structure of the process cartridge and the electrophotographic image forming apparatus using the process cartridge will be described first.

(Overall Structure) This electrophotographic image forming apparatus (laser beam printer, hereinafter referred to as "image forming apparatus") A has information based on image information from an optical system 1 as an optical means, as shown in FIG. The drum-shaped electrophotographic photosensitive member (hereinafter referred to as "photosensitive drum") 7 is irradiated with light to form an electrostatic latent image on the photosensitive drum 7, and the electrostatic latent image is developed (hereinafter referred to as "toner"). It is developed to form a toner image. Then, in synchronization with the formation of the toner image, the recording medium (recording paper, OHP sheet, cloth, etc.) 2 is loaded into the cassette 3
The toner image formed on the photosensitive drum 7 of the process cartridge B is separated from the sheet a by the pickup roller 3b and the pressure contact member 3c that is in pressure contact with the sheet, and is conveyed by the registration roller 3e. 4 is transferred to the recording medium 2 by applying a voltage to
The recording medium 2 is conveyed to the fixing unit 5 by the conveyance guide 3f. The fixing means 5 is composed of a driving roller 5a and a fixing rotator 5d which has a built-in heater 5b and is rotatably supported by a support 5c. The fixing rotator 5d applies heat and pressure to the recording medium 2 passing therethrough. Apply to fix the transferred toner image. Then, the recording medium 2 is conveyed by the pair of discharge rollers 3g and 3h, and is discharged to the discharge section 6 through the reverse transport path. In this embodiment, the conveying means 3 is constituted by the pickup roller 3b, the pressure contact member 3c, the registration roller 3e and the like.

(Process Cartridge) On the other hand, the process cartridge B includes an electrophotographic photosensitive member and at least one process means. Here, as the process means, for example, a charging means for charging the electrophotographic photoreceptor, a developing means for developing the electrostatic latent image formed on the electrophotographic photoreceptor, a cleaning for cleaning the toner remaining on the electrophotographic photoreceptor There are means, etc. As shown in FIG. 2, the process cartridge B of the present embodiment rotates a photosensitive drum 7 which is an electrophotographic photosensitive member having a photosensitive layer and applies a voltage to a charging roller 8 which is a charging means to apply the voltage to the photosensitive drum 7. Surface is uniformly charged, and information light (optical image) based on image information is exposed from the optical system 1 to the charged photosensitive drum 7 through the exposure opening 9 to form an electrostatic latent image. Is formed, and the electrostatic latent image is developed by the developing means 10.

The developing means 10 sends out the toner in the toner containing portion 10a by the rotatable first feeding member 10b2 and second feeding member 10b1 which are toner feeding means. Then, the developing roller 10d, which is a developing rotator (developer carrying member) having the fixed magnet 10c built therein, is rotated, and a toner layer to which a triboelectric charge is applied by the developing blade 10e is formed on the surface of the developing roller 10d. The toner image is formed by transferring toner to the photosensitive drum 7 according to the electrostatic latent image to form a visible image.

Then, after a voltage having a polarity opposite to that of the toner image is applied to the transfer roller 4 to transfer the toner image onto the recording medium 2, the cleaning blade 11a is used for the photosensitive drum 7.
Scrape off the toner remaining on the
The cleaning means 11 collects the residual toner on the photosensitive drum 7 by scooping by 1b and collecting in the removed toner storage portion 11c.

In the process cartridge B shown in this embodiment, the photosensitive drum 7 is rotatably supported, and the cleaning frame 11 having the cleaning means 11 and the charging roller 8 incorporated therein, the developing means 10, and the toner accommodating portion 10a. And a toner developing frame 12 incorporating therein. Then, the toner developing frame 12 is provided with the developing roller 10d of the developing means 10.
Is rotatably supported with respect to the cleaning frame 13 so as to face the photoconductor drum 7 in parallel with a predetermined space therebetween, and a space holding spacer (not shown) is provided between the developing roller 10d and the photoconductor drum 7. (Illustration) is arranged, and a predetermined pressing force is applied to maintain the distance.

That is, the members such as the photosensitive drum 7, the charging roller 8, the developing roller 10d, the cleaning blade 11a, and the like are the toner developing frame in which the developing frame body 12a, the developing lower frame 12b, and the lid member 12c are fused and integrated. The cartridge 12 is housed in a cartridge frame CF configured by combining the body 12 and the cleaning frame 13 to form a cartridge, and is detachably attached to the image forming apparatus body 14 in the arrow X direction.

(Photosensitive Drum) Next, the photosensitive drum 7 according to this embodiment will be described in detail with reference to FIGS. 3 and 4.

FIG. 3 is an external perspective view of the photosensitive drum 7. In the photoconductor drum 7 of this embodiment, an organic photoconductor layer 7b is formed on the outer peripheral surface of a cylinder 7a made of, for example, aluminum, and at the one end in the longitudinal direction of the cylinder 7a, a polyacetal, which is a drive transmission means, A coupling member 7c made of a resin such as polycarbonate, polyamide, or polybutylene terephthalate is provided, and the coupling member 7c is provided with a twisted substantially triangular prism protrusion 7d at the center thereof.

FIG. 4 is a perspective view of the process cartridge B and the gear 18. A gear 18 for receiving the rotational driving force from a motor (not shown) is arranged inside the image forming apparatus main body 14, and a twisted substantially triangular hole 18a is formed at the center of the gear 18. It is provided and is configured to fit with the protrusion 7d. When the gear 18 rotates while these are fitted, the protrusion 7
The rotation of the gear 18 is transmitted to the photosensitive drum 7 in the state where d is pulled in the direction of the substantially triangular hole 18a, that is, the photosensitive drum 7 is twisted toward the driving side (gear 18 side). .

When viewed from the photoconductor drum 7 side, the twisting direction of the protrusion 7d with respect to the rotation direction C of the photoconductor drum 7 is the opposite direction D from the root of the protrusion 7d toward the tip, which is a substantially triangular hole 1.
The twisting direction of 8a is the opposite direction D from the entrance of the substantially triangular hole 18a toward the inside.

By using such a drive transmission means, the drive of the photosensitive drum 7 can be stabilized as compared with the conventional spur gear, and the occurrence of pitch unevenness and the like can be reduced, especially in a halftone image. Higher quality is possible.

(Charging Roller and Bearing) Next, the charging roller 8 according to this embodiment will be described in detail with reference to FIG. FIG. 5 is an external view of the charging roller 8 and the bearing 19.

The charging roller 8 has a structure in which an elastic layer 8b is formed on the outer peripheral surface of a conductive cored bar 8a made of SUS or the like, and a tube made of a resistance layer 8c and a protective layer 8d is coated on the outer peripheral surface. It has become. A so-called adhesive layer is not provided between the elastic layer 8b and the resistance layer 8c. The elastic layer 8b is made of EPDM sponge containing carbon or the like dispersed therein, and secures a good contact state of the charging roller 8 with the surface of the photosensitive drum 7.

Further, the resistance layer 8c formed on the outer peripheral surface thereof.
Is made of urethane rubber containing carbon or the like, and suppresses a leak current to a pinhole even when there is a pinhole on the surface of the photoconductor drum 7 to prevent a sudden drop in voltage.

Further, the protective layer 8d formed on the outer peripheral surface thereof
Is made of methyl methoxylated nylon containing carbon or the like dispersed therein, and prevents the composition material of the elastic layer 8b and the resistance layer 8c from adhering to the surface of the photosensitive drum 7 and deteriorating it.

FIG. 6 is a longitudinal sectional view of the process cartridge B. As a method of supporting the photosensitive drum 7, on the driving side, the inner diameter portion 15a of the drum bearing 15 is rotatably fitted to the shaft portion 7c1 of the coupling member 7c and is fixed to the driving side surface of the cleaning frame body 13. . Similarly, on the non-driving side, the centering shaft 16 and the inner diameter portion 7e1 of the non-driving side flange 7e are rotatably fitted and fixed to the non-driving side surface of the cleaning frame 13.

The charging roller 8 is supported by the cleaning frame 13 by holding both ends of a cored bar 8a penetrating through the center of the charging roller 8 by bearings 19. Furthermore, the bearing 19 is biased toward the photoconductor drum 7 by a pressure spring 20 that is contracted between the bearing 19 and the cleaning frame 13. Therefore, the charging roller 8 supported by the bearing 19 comes into contact with the photosensitive drum 7 with a predetermined pressure such as the urging force of the pressure spring 20 to form an electric circuit. The charging roller 8 does not have a positive driving means,
It is configured to be driven to rotate by the rotation of.

Both bearings 19 are made of a resin material, and at least the bearing 19 on the side supplying power to the charging roller 8 has a conductive material such as carbon filler dispersed in the resin material at the time of molding. As a result, the conductive property is provided such that the resistance value is 10 ^ 3 to 10 ^ 4 (Ω · cm).

Then, by a high voltage power source (not shown) arranged in the main body, for example, a direct current component and an alternating current component are passed through members (not shown) such as a contact point, a pressure spring 20, a power feeding side bearing 19, and a cored bar 8a. The image area on the surface of the photosensitive drum 7 is charged to a predetermined potential by applying an oscillating voltage on which is superimposed.

(First Embodiment) Next, a first embodiment of the charging roller 8 and the bearing 19 according to the present invention will be described in detail with reference to FIGS. 7 to 12.

FIG. 7 is an external perspective view of the charging roller 8 according to this embodiment. A tapered portion 8a1 is arranged at the end of the cored bar 8a. The tapered portion 8a1 has a shape in which the shaft diameter of the cored bar 8a becomes smaller toward the end surface 8e2.

8 and 9 show the bearing 19 according to this embodiment.
FIG.

As shown in FIG. 8, the bearing 19 is provided with a contact portion 19a which comes into contact with the tapered portion 8a1.

As shown in FIG. 9, since the bearing 19 is made of a resin material, when the bearing 19 is fitted on the core metal 8a of the charging roller 8, the bearing 19 is formed so that the contact portion 19a follows the shape of the tapered portion 8a1. Deform.

FIG. 10 is an external view of the bearing 19 according to this embodiment when it is attached to the cleaning frame 13. The cleaning frame 13 has a bearing guide 13a inside, and the bearing 1
9 is supported by the cleaning frame 13 by being inserted into the bearing guide 13a, and is movable along the bearing guide 13a. Further, the bearing 19 and the cleaning frame 13
Since the pressure spring 20 is contracted between and, and is supported by the cleaning frame 13 as described above, the charging roller 8 is pressed against the photosensitive drum 7 by the urging force of the pressure spring 20. It Further, the bearing 19 will not fall off the bearing guide 13a by the urging force of the pressure spring 20 due to the stopper 13b.

FIG. 11 is a vertical cross-sectional view of the bearing 19 according to this embodiment. The core metal 8a of the charging roller 8 is fitted in the bearing 19, and the charging roller 8 is biased by the pressure spring 20 toward the photoconductor drum 7. Therefore, the surface of the tapered portion 8a1 is urged by the pressure spring 20 and the bearing. The pressing force F due to the holding force of 19 or the like is received. This pressing force F is divided by the tapered surface into a component force Fa acting in the longitudinal thrust direction and a component force Fb acting in the axial direction of the charging roller 8.

FIG. 12 is a longitudinal sectional view of the process cartridge B according to this embodiment. A reference surface E serving as a position reference of the charging roller 8 is provided at the taper portion 8a1 of the charging roller 8 and the other end side in the longitudinal direction of the cleaning frame 13 at the abutting portion 19b of the bearing 19 on the other end side. The charging roller 8 moves in the longitudinal thrust direction G by the component force Fa in the longitudinal thrust direction described above.
The end surface 8e1 on the other end side of the end abuts the reference surface E, and the movement in the direction G ends. Since the end surface 8e1 of the charging roller 8 is always in contact with the reference surface E regardless of whether the charging roller 8 is stationary or in operation, the charging roller 8 stabilizes the position in the longitudinal thrust direction with respect to the cleaning frame 13 and the photosensitive drum 7. be able to.

(Second Embodiment) Next, a second embodiment of the charging roller 8 and the bearing 19 according to the present invention will be described with reference to FIG.
It will be described in detail with reference to FIGS.

FIG. 13 is an external perspective view of the charging roller 8 according to this embodiment. The tapered portion 8a1 is provided at the end of the cored bar 8a.
Is provided. The tapered portion 8a1 has a shape in which the shaft diameter of the cored bar 8a becomes thicker toward the end surface 8e2.

14 and 15 are longitudinal sectional views of the bearing 19 according to this embodiment.

As shown in FIG. 14, the bearing 19 has a tapered portion 8a1.
A contact portion 19a that comes into contact with is provided.

As shown in FIG. 15, since the bearing 19 is made of a resin material, when the bearing 19 is fitted on the core metal 8a of the charging roller 8, the bearing 19 is formed so that the contact portion 19a follows the shape of the tapered portion 8a2. Deform.

FIG. 16 is a vertical cross-sectional view of the bearing 19 according to this embodiment. The core metal 8a of the charging roller 8 is fitted in the bearing 19, and the charging roller 8 is biased by the pressure spring 20 toward the photoconductor drum 7. Therefore, the surface of the tapered portion 8a2 is urged by the pressure spring 20 and the bearing. The pressing force F due to the holding force of 19 or the like is received. This pressing force F is divided by the tapered surface into a component force Fa acting in the longitudinal thrust direction and a component force Fb acting in the axial direction of the charging roller 8.

FIG. 17 is a longitudinal sectional view of the process cartridge B according to the present invention. A reference surface E serving as a position reference of the charging roller 8 is provided at the abutting portion 19b of the bearing 19 on the same side on the same side in the longitudinal direction of the taper portion 8a2 of the charging roller 8 and the cleaning frame body 13. The charging roller 8 moves in the direction G by the component force Fa in the longitudinal thrust direction described above.
However, the end surface 8e1 on the other end side of the charging roller 8 hits the reference surface E, and the movement in the direction G ends. Similar to the first embodiment, the charging roller 8 can be used regardless of whether it is stationary or operating.
Since the end surface 8e1 of the charging roller 8 is always in contact with the reference surface E, the position of the charging roller 8 in the longitudinal thrust direction with respect to the cleaning frame body 13 and the photosensitive drum 7 can be stabilized.

(Third Embodiment) Next, a third embodiment of the present invention will be described in detail with reference to FIG.

FIG. 18 is a longitudinal sectional view of the process cartridge B according to the present invention. Cleaning frame 13
In the longitudinal direction, the tapered portion 8a described in detail in the second embodiment is provided on the cored bar 8a of the charging roller 8 on the side where the photosensitive drum 7 is driven.
2. By disposing the tapered portion 8a1 described in detail in the first embodiment on the non-driving side of the photosensitive drum 7, the moving force of the charging roller 8 in the direction G due to the component force Fa increases. Also, the first
The reference surface E as in the first embodiment and the second embodiment.
By disposing the charging roller 8 at the abutting portion 19b of 9, the position of the charging roller 8 in the longitudinal thrust direction with respect to the cleaning frame 13 and the photosensitive drum 7 can be stabilized. By increasing the moving force in the direction G, the position of the charging roller 8 can be made more stable in the configuration of the third embodiment as compared with the first and second embodiments.

The material of the bearing 19 according to the present invention is
In order to generate the component force Fa by the tapered surfaces 8a1 and 8a2, it is preferable that the elastic restoration body is used.

Since at least one of the bearings 19 constitutes a part of a power feeding path from the image forming apparatus main body 14 to the charging roller 8, it is preferable that the bearing 19 is a conductive member.

The electrophotographic photoconductor 7 is not limited to the photoconductor drum, and includes, for example, the following. First, a photoconductor is used as the photoconductor, and examples of the photoconductor include amorphous silicon, amorphous selenium, zinc oxide, titanium oxide, and organic photoconductor (O).
PC) is included. Further, as a shape for mounting the photosensitive member, for example, a drum shape or a belt shape is used. For example, in the case of a drum type photosensitive member, a photoconductor is vapor-deposited or coated on an aluminum alloy cylinder. It was done.

As the developing method, various known developing methods such as a two-component magnetic brush developing method, a cascade developing method, a touchdown developing method and a cloud developing method can be used.

Further, as a method of cleaning the toner remaining on the photosensitive drum, the cleaning means may be constituted by using a blade, a fur brush, a magnetic brush or the like.

The above-mentioned process cartridge includes, for example, an electrophotographic photosensitive member and at least one process means. Therefore, as the mode of the process cartridge, other than the embodiment described above, for example, the electrophotographic photosensitive member and the charging unit are integrally made into a cartridge, which can be attached to and detached from the apparatus main body. The electrophotographic photosensitive member and the developing means are integrally formed into a cartridge,
It can be attached to and detached from the device body. Further, there is one in which the electrophotographic photosensitive member 7 and two or more of the above-mentioned process means are combined into an integrated cartridge so as to be attachable to and detachable from the apparatus main body.

That is, the above-mentioned process cartridge is one in which the charging means, the developing means or the cleaning means and the electrophotographic photosensitive member are integrally made into a cartridge, and the cartridge can be attached to and detached from the main body of the image forming apparatus. . Also, at least one of the charging means, the developing means, and the cleaning means and the electrophotographic photosensitive member are integrally made into a cartridge so as to be attachable to and detachable from the main body of the image forming apparatus. Further, it means that at least the developing means and the electrophotographic photosensitive member are integrally made into a cartridge so as to be attachable to and detachable from the main body of the image forming apparatus. Then, this process cartridge can be attached to and detached from the apparatus main body by the user himself. Therefore, the maintenance of the image forming apparatus main body can be performed by the user himself.

Further, in the above-mentioned embodiment, the laser beam printer is exemplified as the electrophotographic image forming apparatus, but the present invention is not limited to this, and it is possible to use, for example, an electrophotographic copying machine, a facsimile machine, or an electronic device such as a word processor. It may also be used in a photographic image forming apparatus.

[0083]

As described above, at least the electrophotographic photosensitive member, the charging unit for charging the electrophotographic photosensitive member, and the supporting unit for supporting the charging unit are provided and can be attached to and detached from the main body of the image forming apparatus. In this process cartridge, an inclined surface portion is provided at the end of the charging means, and the supporting means holds the inclined surface portion to support the charging means, thereby stabilizing the longitudinal position of the charging means. Therefore, it is possible to save space in the longitudinal direction of the process cartridge and the image forming apparatus without significantly increasing the cost.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a schematic description of an electrophotographic image forming apparatus.

FIG. 2 is a sectional view showing a schematic configuration of a process cartridge.

FIG. 3 is an external perspective view of an electrophotographic photosensitive member.

FIG. 4 is a perspective view of a process cartridge and a drive transmission gear.

[Fig. 5] Appearance diagram of charging roller and bearing

FIG. 6 is a longitudinal sectional view of a process cartridge.

FIG. 7 is an external perspective view of the charging roller according to the first embodiment of the present invention.

FIG. 8 is a longitudinal sectional view of a bearing according to the first embodiment of the present invention.

FIG. 9 is a longitudinal sectional view of a bearing according to the first embodiment of the present invention.

FIG. 10 is an external view of the bearing according to the first embodiment of the present invention when it is attached to a cleaning frame.

FIG. 11 is a longitudinal sectional view of a bearing according to the first embodiment of the present invention.

FIG. 12 is a longitudinal sectional view of the process cartridge according to the first embodiment of the present invention.

FIG. 13 is an external perspective view of the charging roller 8 according to the second embodiment of the present invention.

FIG. 14 is a vertical sectional view of a bearing according to a second embodiment of the present invention.

FIG. 15 is a longitudinal sectional view of a bearing according to a second embodiment of the present invention.

FIG. 16 is a longitudinal sectional view of a bearing according to a second embodiment of the present invention.

FIG. 17 is a longitudinal sectional view of a process cartridge according to a second embodiment of the present invention.

FIG. 18 is a longitudinal sectional view of a process cartridge according to a third embodiment of the present invention.

[Explanation of symbols]

1 Optical system 2 recording media 3 transportation means 3a cassette 3b Pickup roller 3c Pressure contact member 3e Registration roller 3f transport guide 3g, 3h Ejection roller pair 4 Transfer roller 5 fixing means 5a drive roller 5b heater 5c support 5d fixing rotating body 6 discharge part 7 Electrophotographic photoconductor (photoconductor drum) 7a cylinder 7b Organic photoconductor layer 7c Coupling member 7c1 shaft 7d Approximately triangular prismatic protrusion 7e Non-driving side flange 7e1 inner diameter 8 Charging means (charging roller) 8a core 8a1, 8a2 taper part 8b elastic layer 8c resistance layer 8d protective layer 8e1, 8e2 end face 9 Exposure opening 10 developing means 10a toner container 10b1 second feeding member 10b2 first feeding member 10c fixed magnet 10d developing roller 10e Development blade 11 Cleaning means 11a cleaning blade 11b Squishy sheet 11c Removing toner container 12 toner development frame 12a Development frame 12b Development bottom frame 12c lid member 13 Cleaning frame 13a Bearing guide 13b stopper 14 Image forming apparatus main body 15 Drum bearing 15a inner diameter 16 centering axis 18 gears 18a approximately triangular hole 19 bearings 19a contact part 19b Butt part 20 pressure spring A image forming apparatus B process cartridge C, D, G direction CF cartridge frame E reference plane F pressing force Fa, Fb component force

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2H071 BA04 BA16 BA22 BA29 DA06                       DA15                 2H200 FA02 GA23 GA34 GA46 GB12                       GB25 GB41 HA02 HA28 HB12                       HB22 HB43 HB45 JA02 JB10                       LA01 LA13 LA38 MA02

Claims (18)

[Claims] 1. A process cartridge detachable from an image forming apparatus main body, comprising at least an electrophotographic photosensitive member, a charging unit for charging the electrophotographic photosensitive member, and a supporting unit for supporting the charging unit. A process cartridge, wherein an inclined surface portion is disposed at an end portion of the charging means, and the supporting means supports the charging means by holding the inclined surface portion. 2. A longitudinal positioning portion for positioning the charging member in the longitudinal direction is provided on one end side of the process cartridge in the longitudinal direction, and the inclined surface portion is provided on the other end of the charging means. The process cartridge according to claim 1, wherein the process cartridge is provided. 3. The process cartridge is provided with the longitudinal positioning portion on one end side in the longitudinal direction, and the inclined surface portion is provided on the end portion of the charging means on the same one end side. Item 1. The process cartridge according to Item 1. 4. The longitudinal direction positioning portion is disposed on one end side in the longitudinal direction of the process cartridge, and the inclined surface is disposed on both end portions of the charging means on one end side and the other end side. The process cartridge according to claim 1. 5. The charging means is a charging roller for contact-charging the electrophotographic photosensitive member, the charging roller including at least a metal shaft and an elastic body, and the inclined surface portion is disposed at the other end of the metal shaft. The inclined surface of the inclined surface portion has a shape in which the shaft diameter becomes smaller toward the other end side end surface of the metal shaft of the charging roller, and the support member holds the inclined surface portion to enable rotation of the charging roller. The process cartridge according to claim 2, which is a bearing member that supports the process cartridge. 6. The charging means is a charging roller which is composed of at least a metal shaft and an elastic body for contact-charging the electrophotographic photosensitive member, wherein the inclined surface portion is disposed on one end side of the metal shaft, and the inclined surface portion is provided. The inclined surface has a shape in which the diameter of the shaft becomes thicker toward the one end side end surface of the metal shaft of the charging roller, and the supporting member holds the inclined surface portion to rotatably support the charging roller. The process cartridge according to claim 3, wherein 7. The charging means is a charging roller composed of at least a metal shaft and an elastic body that contact-charges the electrophotographic photosensitive member, and inclined surfaces are provided at both ends of the metal shaft, and the other end side thereof is provided. The inclined surface of the inclined surface portion has a shape in which the shaft diameter becomes smaller toward the end surface on the other end side of the metal shaft of the charging roller, and the inclined surface of the inclined surface portion on the one end side corresponds to the metal shaft of the charging roller. 5. The bearing member has a shape in which the shaft diameter becomes thicker toward the one end side end face, and the support member is a bearing member that rotatably supports the charging roller by holding the inclined surface portion. Process cartridge. 8. The process cartridge according to claim 5, wherein the bearing member is made of an elastic restoration body. 9. The process cartridge according to claim 5, wherein the bearing member is made of a conductive member. 10. At least: (a) an electrophotographic photosensitive member; (b) a charging unit that charges the electrophotographic photosensitive member and an inclined surface portion is disposed at an end; and (c) holds the inclined surface portion. An image forming apparatus, wherein a process cartridge including a supporting unit that supports the charging unit is detachable. 11. In the process cartridge, (a) a longitudinal direction positioning portion for longitudinally positioning the charging member at one end side in the longitudinal direction, and (b) an inclination at the other end side in the longitudinal direction. The image forming apparatus according to claim 10, wherein the process cartridge including the charging unit having a surface portion is detachable. 12. In the process cartridge, (a) a longitudinal direction positioning portion for positioning the charging member in the longitudinal direction at one end side in the longitudinal direction, and (b) having the inclined surface portion at the end portion at the same one end side. The image forming apparatus according to claim 10, wherein the process cartridge including the charging unit is removable. 13. In the process cartridge, (a) a longitudinal direction positioning portion for positioning the charging member in the longitudinal direction at one end side in the longitudinal direction, and (b) an inclination at both end portions on one end side and the other end side. The image forming apparatus according to claim 10, wherein the process cartridge including the charging unit having a surface portion is detachable. 14. In the process cartridge, (a) a charging roller which comprises at least a metal shaft and an elastic body for contact-charging the electrophotographic photosensitive member, and (b) a metal shaft end portion of the charging roller, and an end surface on the other end side. The process cartridge having a bearing member that rotatably supports the charging roller by holding the inclined surface portion (c) is provided. The image forming apparatus according to claim 11, wherein: 15. The process cartridge according to claim 1, wherein: (a) a charging roller including at least a metal shaft and an elastic body for contact-charging the electrophotographic photosensitive member, and (b) a metal shaft end portion of the charging roller, and an end surface on one end side. The inclined surface portion (c) having an inclined surface whose shaft diameter becomes thicker toward the side (c) A process cartridge including a bearing member that rotatably supports the charging roller by holding the inclined surface portion is removable. The image forming apparatus according to claim 12, wherein 16. In the process cartridge, (a) a charging roller which comprises at least a metal shaft and an elastic body for contact-charging the electrophotographic photosensitive member, and (b) is located at both ends of the metal shaft of the charging roller, and is on the other end side. Has a shape in which the shaft diameter decreases toward the end surface on the other end side, and the one end side has an inclined surface in which the shaft diameter increases toward the end surface on the one end side. 14. The image forming apparatus according to claim 13, wherein a process cartridge including a bearing member that rotatably supports the charging roller is detachable. 17. The image forming apparatus according to claim 14, wherein a process cartridge provided with the bearing member made of an elastic restoration body is detachable. 18. The image forming apparatus according to claim 14, wherein the process cartridge provided with the bearing member made of a conductive member is detachable.