AU2021202841B2 - Process cartridge, electrophotographic image forming apparatus and electrographic photosensitive drum unit - Google Patents

Abstract

PROCESS CARTRIDGE, ELECTROPHOTOGRAPHIC IMAGE FORMING APPARATUS AND ELECTROGRAPHIC PHOTOSENSTIVE DRUM UNIT ABSTRACT A process cartridge which is detachably mountable to a main assembly of an electrophotographic 5 image forming apparatus including a driving shaft having a rotational force applying portion by moving in a direction substantially perpendicular to an axis of the driving shaft, includes i) an electrophotographic photosensitive drum rotatable 10 about an axis; ii) process means actable on the drum; iii) a coupling member engageable with the rotational force applying portion to receive a rotational force for rotating the drum, the coupling member being capable of taking a rotational force transmitting 15 angular position for transmitting the rotational force for rotating the drum to the drum, a pre-engagement angular position in which the coupling member is inclined away from the axis from the rotational force transmitting angular position and a disengaging 20 angular position in which the coupling member is inclined away from the axis from the rotational force transmitting angular position; and iv) a regulating portion for regulating an inclination angle of the coupling member such that downward inclination angle 25 of the coupling member is smaller than an inclination angle of the coupling member when the coupling member is at the pre-engagement angular position, wherein in 7274655vl mounting the cartridge to the main assembly by moving the cartridge in the direction, the coupling member moves from the pre-engagement angular position to the rotational force transmitting angular position to 5 oppose the driving shaft, and in dismounting the cartridge from the main assembly by moving the cartridge in the direction, the coupling member moves from the rotational force transmitting angular position to the disengaging angular position to 10 disengage from the driving shaft. 7274655vl

Description

mounting the cartridge to the main assembly by moving

the cartridge in the direction, the coupling member

moves from the pre-engagement angular position to the

rotational force transmitting angular position to

oppose the driving shaft, and in dismounting the

cartridge from the main assembly by moving the

cartridge in the direction, the coupling member moves

from the rotational force transmitting angular

position to the disengaging angular position to

disengage from the driving shaft.

7274655vl

DESCRIPTION PROCESS CARTRIDGE, ELECTROPHOTOGRAPHIC IMAGE FORMING APPARATUS AND ELECTROGRAPHIC PHOTOSENSTIVE DRUM UNIT

[CROSS REFERENCE] The present application is a divisional application of Australian Patent Application No. 2019210524, in turn a divisional application of Australian Patent Application No. 2017210609, filed on 4 August 2017, in turn a divisional application of Australian Patent Application No. 2014277817. Australian Patent Application No. 2014277817 was a divisional application of Australian Patent Application No. 2013202177. Australian Patent Application No. 2013202177 was a divisional application of Australian Patent Application No. 2009261109, which in turn was derived from International Patent Application No. PCT/JP2009/061673, filed on 19 June 2009. Australian Patent Application No. 2019210524 is hereby incorporated by reference in its entirety as if fully set forth herein.

[TECHNICAL FIELD] The present invention relates to a process cartridge, an electrophotographic image forming apparatus to which the process cartridge is detachably mountable, and an electrophotographic photosensitive drum unit.

The electrophotographic image forming apparatus includes an electrophotographic copying machine and an electrophotographic printer (laser beam printer, LED printer, and so on).

The process cartridge contains, as a unit, an electrophotographic photosensitive member and process means actable on said electrophotographic photosensitive member, and is detachably mountable to a main assembly of the electrophotographic image forming apparatus. For example, the process cartridge contains an electrophotographic photosensitive member and at least one of developing means, charging means and cleaning means which are the process means, as a unit. Therefore, an example of the process cartridge comprises an electrophotographic photosensitive member and developing means, charging means and cleaning means which are the process means, as a unit. Another example of the process cartridge comprises an electrophotographic photosensitive member and charging means as the process means, as a unit. A further example of the process cartridge comprises an electrophotographic photosensitive member and charging means and cleaning means as the process means, as a unit. An even further example of the process cartridges comprises an electrophotographic photosensitive member and developing means as the process means, as a unit.

The apparatus main assembly of the

electrophotographic image forming apparatus is parts

of the electrophotographic image forming apparatus

except the process cartridge.

The process cartridge can be mounted to and

dismounted from the main assembly of the apparatus.

Therefore, the maintenance operation of the apparatus

can be carried out in effect by the user without

relying on the service person- This improves the

maintenance operativity of the image forming apparatus.

[BACKGROUND ART]

In the field of the process cartridge, in order

to receive the rotational driving force for rotating the drum -shaped electrophotographic photosensitive member (drum) from the main assembly, following structure is known.

The main assembly of the apparatus includes a

rotatable member for transmitting a driving force of a

motor and includes a twisted hole which is provided at

a center of said rotatable member and which has a non

circular cross-section having a plurality of corner

portions. The process cartridge includes a twisted

projection which has a non-circular cross-section

having a plurality of corner portions and which is

provided on one longitudinal end of the drum, the

twisted projection being engageable with the twisted

hole of the rotatable member. After the process

cartridge is mounted to the main assembly when the

rotatable member rotates in the state that the

projection is in engagement with the hole, the

rotational force is transmitted from the rotatable

member to the drum, while the projection receives the

retracting force in the direction toward the hole. By

this, the rotational force for rotating the drum is

transmitted from the main assembly to the

photosensitive drum (Japanese Patent No. 2875203).

In another known system, a gear fixed to the

drum of the process cartridge is engaged with a

driving gear of the main assembly to rotate the drum

(Japanese Patent 1604488).

Some embodiments of present invention further develops the prior art described above. SUMMARY It is an object of the present invention to substantially overcome, or at least ameliorate, one or more disadvantages of existing arrangements. One aspect of the present disclosure provides a process cartridge which is detachably mountable to a main assembly of an electrophotographic image forming apparatus including a driving shaft having a rotational force applying portion, by moving in a mounting direction substantially perpendicular to an axis of said driving shaft, said process cartridge comprising: i) a bearing member; ii) a photosensitive drum supported by said bearing member rotatably about a drum axis thereof; iii) a coupling member provided at an axial end portion of said photosensitive drum and rotatable about a coupling axis thereof so as to transmit a driving force from the driving shaft to said photosensitive drum, said coupling member being capable of moving relative to said photosensitive drum between a first position in which said coupling axis is coaxial with said drum axis and a second position in which said coupling axis is not coaxial with said drum axis; and iv) a hole portion provided on said bearing member and penetrated by said coupling member, said hole portion being configured to regulate the motion of said coupling member, wherein said hole portion is provided with a recess that is recessed along the mounting direction away from said drum axis, wherein said coupling member moves from the first position to the second position by a movement away from said drum axis toward said recess, and wherein a movable range of the coupling member away from said drum axis along the mounting direction toward the recess is larger than a movable range of the coupling member away from said drum axis along another direction. It is desired to provide a process cartridge which is mountable to the main assembly which is not provided with the mechanism for moving the main assembly side coupling member for transmitting the rotational force to the drum, by the opening and closing operation of the main assembly cover in the axial direction, the process cartridge being capable of rotating the drum smoothly. Disclosed is an electrophotographic photosensitive drum unit usable with the process cartridge and the electrophotographic image forming apparatus relative to which the process cartridge is mountable and dismountable. Also disclosed is a process cartridge which is dismountable in a direction perpendicular to an axis of a driving shaft from the main assembly provided with the driving shaft.

4a

Also disclosed is an electrophotographic photosensitive drum unit usable with such the process cartridge and an electrophotographic image forming apparatus to which such a process cartridge is detachably mountable.

Also disclosed is a process cartridge mounted to the main assembly provided with a driving shaft in a direction substantially perpendicular to an axis of the driving shaft.

Also disclosed is an electrophotographic photosensitive drum unit usable with the process cartridge and an electrophotographic image forming apparatus to which such a process cartridge is detachably mountable.

Also disclosed is a process cartridge mountable and dismountable in a direction substantially perpendicular to an axis of the driving shaft relative to the main assembly provided with the driving shaft.

Also disclosed is an electrophotographic photosensitive drum unit usable with such the process cartridge and an electrophotographic image forming apparatus to which such a process cartridge is detachably mountable.

Also disclosed is a process cartridge in which the rotational accuracy of the electrophotographic photosensitive drum is improved as compared with the in the case where the engagement between gears is used for the transmission of a rotational force to the process cartridge from a main assembly.

Also disclosed is an electrophotographic photosensitive drum unit usable with the process cartridge and an electrophotographic image forming apparatus on which the process cartridge is detachably mountable.

Also disclosed is a process cartridge which has a regulating portion for regulating the inclination angle of the coupling member so that the angle at which the coupling member inclines by the weight is smaller than the angle in the case where the coupling member is in the pre-engagement angular position.

Also disclosed is an electrophotographic photosensitive drum unit usable with the process cartridge and the electrophotographic image forming apparatus on which the process cartridge is detachably mountable.

Also disclosed is a process cartridge in which before mounting the cartridge to a main assembly, the coupling is prevented from inclining greatly in the unnecessary direction, by which the cartridge can be smoothly mounted to the main assembly.

Also disclosed is an electrophotographic photosensitive drum unit usable for such a process cartridge and an electrophotographic image forming apparatus to which such a process cartridge is detachably mountable.

Also disclosed is a process cartridge which is mounted and dismounted in the direction substantially perpendicular to an axis of the driving shaft provided in a main assembly, and the electrophotographic photosensitive drum provided therein is rotated smoothly. Also disclosed is the electrophotographic photosensitive drum unit usable for such a process cartridge and an electrophotographic image forming apparatus to which such a process cartridge is detachably mountable. One aspect of the present disclosure provides a process cartridge which is detachably mountable to a main assembly of an electrophotographic image forming apparatus including a driving shaft having a rotational force applying portion, by moving in a mounting direction substantially perpendicular to an axis of said driving shaft, said process cartridge comprising: i) a photosensitive drum rotatable about a drum axis thereof; ii) a coupling member provided at an axial end portion of said photosensitive drum and rotatable about a coupling axis thereof so as to transmit a driving force from the driving shaft to said photosensitive drum, said coupling member being capable of moving relative to said photosensitive drum between a first position in which said coupling axis is coaxial with said drum axis and a second position in which said coupling axis is not coaxial with said drum axis; and iii) a hole portion surrounding said coupling member, wherein said hole portion is provided with a recess that is recessed along the mounting direction away from said drum axis, and wherein a movable range of the coupling member away from said drum axis along the mounting direction toward the recess is larger than a movable range of the coupling member away from said drum axis along another direction. Another aspect of the present invention provides a process cartridge which is detachably mountable to a main assembly of an electrophotographic image forming apparatus including a driving shaft having a rotational force applying portion by moving in a mounting direction substantially perpendicular to an axis of said driving shaft, said process cartridge comprising: i) an electrophotographic photosensitive drum rotatable about an axis and having a photosensitive layer at its peripheral surface; ii) process means actable on said electrophotographic photosensitive drum; iii) a coupling member engageable with said rotational force applying portion to receive a rotational force for rotating said electrophotographic photosensitive drum, said coupling member being capable of taking a rotational force transmitting angular position for transmitting the rotational force for rotating said electrophotographic photosensitive drum to said electrophotographic photosensitive drum and a pre engagement angular position in which said coupling member is inclined away from the axis of said electrophotographic photosensitive drum from said rotational force transmitting

6a angular position; and iv) a regulating portion for regulating an inclination angle of said coupling member such that downward inclination angle of said coupling member is smaller than an inclination angle of said coupling member when said coupling member is at the pre engagement angular position, wherein in mounting said process cartridge to the main assembly of the apparatus by moving said process cartridge in the mounting direction substantially perpendicular to the axis of said electrophotographic photosensitive drum, said coupling member moves from the pre engagement angular position to the rotational force transmitting angular position to engage with the driving shaft, wherein said regulating portion surrounds said coupling member as seen in a direction along the axis of said electrophotographic photosensitive drum, wherein said regulating portion includes a recessed portion, recessed away from the axis of said electrophotographic photosensitive drum in the mounting direction, for regulating the inclination angle of the coupling member in the pre engagement angular position. Another aspect of the present invention provides an electrophotographic image forming apparatus comprising: i) a main assembly including a driving shaft having a rotating force applying portion; and ii) a process cartridge, detachably mountable to said main assembly, including, an electrophotographic photosensitive drum rotatable about an axis and having a photosensitive layer at its peripheral surface; process means actable on said electrophotographic photosensitive drum; a coupling member engageable with said rotational force applying portion to receive a rotational force for rotating said electrophotographic photosensitive drum, said coupling member being capable of taking a rotational force transmitting angular position for transmitting the rotational force for rotating said electrophotographic photosensitive drum to said electrophotographic photosensitive drum and a pre engagement angular position in which said coupling member is inclined away from the axis of said electrophotographic photosensitive drum from said rotational force transmitting angular position; and a regulating portion for regulating an inclination angle of said coupling member such that downward inclination angle of said coupling member is smaller than an inclination angle of said coupling member when said coupling member is at the pre engagement angular position; wherein in mounting said process cartridge to the main assembly of the apparatus by moving said process cartridge in a mounting direction substantially perpendicular to the axis of said electrophotographic photosensitive drum, said coupling member moves from the pre engagement angular position to the rotational force transmitting angular position to engage with the driving shaft, wherein said regulating portion surrounds said coupling member as seen in a direction along the axis of said electrophotographic photosensitive drum, wherein said regulating portion includes a recessed

6b portion, recessed away from the axis of said electrophotographic photosensitive drum in the mounting direction, for regulating the inclination angle of the coupling member in the pre engagement angular position. Another aspect of the present invention provides an electrophotographic photosensitive drum unit which is detachably mountable to a main assembly of an electrophotographic image forming apparatus including a driving shaft having a rotational force applying portion by moving in a mounting direction substantially perpendicular to an axis of said driving shaft, said drum unit comprising: i) an electrophotographic photosensitive drum rotatable about an axis and having a photosensitive layer at its peripheral surface; ii) a coupling member engageable with said rotational force applying portion to receive a rotational force for rotating said electrophotographic photosensitive drum, said coupling member being capable of taking a rotational force transmitting angular position for transmitting the rotational force for rotating said electrophotographic photosensitive drum to said electrophotographic photosensitive drum and a pre engagement angular position in which said coupling member is inclined away from the axis of said electrophotographic photosensitive drum from said rotational force transmitting angular position; iii) a regulating portion for regulating an inclination angle of said coupling member such that downward inclination angle of said coupling member is smaller than an inclination angle of said coupling member when said coupling member is at the pre engagement angular position; wherein in mounting said process cartridge to the main assembly of the apparatus by moving said process cartridge in the mounting direction substantially perpendicular to the axis of said electrophotographic photosensitive drum, said coupling member moves from the pre engagement angular position to the rotational force transmitting angular position to engage with the driving shaft, wherein said regulating portion surrounds said coupling member as seen in a direction along the axis of said electrophotographic photosensitive drum, wherein said regulating portion includes a recessed portion, recessed away from the axis of said electrophotographic photosensitive drum in the mounting direction, for regulating the inclination angle of the coupling member in the pre engagement angular position. According to another aspect of the present disclosure, there is provided a process cartridge which is detachably mountable to a main assembly of an electrophotographic image forming apparatus including a driving shaft having a rotational force applying portion by moving in a direction substantially perpendicular to an axis of said driving shaft, said process cartridge comprising: i) an electrophotographic photosensitive drum rotatable about an axis and having a photosensitive layer at its peripheral surface;

6c ii) process means actable on said electrophotographic photosensitive drum; iii) a coupling member engageable with said rotational force applying portion to receive a rotational force for rotating said electrophotographic photosensitive drum, said coupling member being capable of taking a rotational force transmitting angular position for transmitting the rotational force for rotating said electrophotographic photosensitive drum to said electrophotographic photosensitive drum, a pre-engagement angular position in which said coupling member is inclined away from the axis of said electrophotographic photosensitive drum from said rotational force transmitting angular position and a disengaging angular position in which said coupling member is inclined away from the axis of said electrophotographic photosensitive drum from said rotational force transmitting angular position; and iv) a regulating portion for regulating an inclination angle of said coupling member such that downward inclination angle of said coupling member is smaller than an inclination angle of said coupling member when said coupling member is at the pre- engagement angular position, wherein in mounting said process cartridge to the main assembly of the apparatus by moving said process cartridge in a direction substantially perpendicular to the axis of said electrophotographic photosensitive drum, said coupling member moves from the pre-engagement- angular position to the rotational force transmitting angular position to oppose the driving shaft, and in dismounting said process cartridge from the main assembly of the apparatus by moving said process cartridge in the direction substantially perpendicular to the axis of said electrophotographic photosensitive drum, said coupling member moves from the rotational force transmitting angular position to the disengaging angular position to disengage from the driving shaft.

According to another aspect of the present disclosure, there is provided an electrophotographic image forming apparatus to which a process cartridge is detachably mountable to a main assembly of the apparatus, said electrophotographic image forming apparatus comprising: i) a driving shaft having a rotating force applying portion; and ii) a process cartridge including, an electrophotographic photosensitive drum rotatable about an axis and having a photosensitive layer at its peripheral surface; process means actable on said electrophotographic photosensitive drum; a coupling member engageable with said rotational force applying portion to receive a rotational force for rotating said electrophotographic photosensitive drum, said coupling member being capable of taking a rotational force transmitting angular position for transmitting the rotational force for rotating said electrophotographic photosensitive drum to said electrophotographic photosensitive drum, a pre engagement angular position in which said coupling member is inclined away from the axis of said electrophotographic photosensitive drum from said rotational force transmitting angular position and a disengaging angular position in which said coupling member is inclined away from the axis of said electrophotographic photosensitive drum from said rotational force transmitting angular position; and a regulating portion for regulating an inclination angle of said coupling member such that downward inclination angle of said coupling member is smaller than an inclination angle of said coupling member when said coupling member is at the pre engagement angular position; wherein in mounting said process cartridge to the main assembly of the apparatus by moving said process cartridge in a direction substantially perpendicular to the axis of said electrophotographic photosensitive drum, said coupling member moves from the pre-engagement angular position to the rotational force transmitting angular position to oppose the driving shaft, and in dismounting said process cartridge from the main assembly of the apparatus by moving said process cartridge in the direction substantially perpendicular to the axis of said electrophotographic photosensitive drum, said coupling member moves from the rotational force transmitting angular position to the disengaging angular position to disengage from the driving shaft.

According to a further aspect of the present disclosure, there is provided an electrophotographic photosensitive drum unit which is detachably mountable to a main assembly of an electrophotographic image forming apparatus including a driving shaft having a rotational force applying portion by moving in a direction substantially perpendicular to an axis of said driving shaft, said process cartridge comprising: i) an electrophotographic photosensitive drum rotatable about an axis and having a photosensitive layer at its peripheral surface; ii) a coupling member engageable with said rotational force applying portion to receive a rotational force for rotating said electrophotographic photosensitive drum, said coupling member being capable of taking a rotational force transmitting angular position for transmitting the rotational force for rotating said electrophotographic photosensitive drum to said electrophotographic photosensitive drum, a pre engagement angular position in which said coupling member is inclined away from the axis of said electrophotographic photosensitive drum from said rotational force transmitting angular position and a disengaging angular position in which said coupling member is inclined away from the axis of said electrophotographic photosensitive drum from said rotational force transmitting angular position; iii) a regulating portion for regulating an inclination angle of said coupling member such that downward inclination angle of said coupling member is smaller than an inclination angle of said coupling member when said coupling member is at the pre engagement angular position; wherein in mounting said process cartridge to the main assembly of the apparatus by moving said process cartridge in a direction substantially perpendicular to the axis of said electrophotographic photosensitive drum, said coupling member moves from the pre-engagement angular position to the rotational force transmitting angular position to oppose the driving shaft, and in dismounting said process cartridge from the main assembly of the apparatus by moving said process cartridge in the direction substantially perpendicular to the axis of said electrophotographic photosensitive drum, said coupling member moves from the rotational force transmitting angular position to the disengaging angular position to disengage from the driving shaft.

According to another aspect of the present disclosure, there is provided a process cartridge which is detachably mountable to a main assembly of an electrophotographic image forming apparatus including a driving shaft having a rotational force applying portion, by moving in a mounting direction substantially perpendicular to an axis of said driving shaft, said process cartridge comprising: i) a photosensitive drum rotatable about a drum axis thereof; ii) a coupling member provided at an axial end portion of said photosensitive drum and rotatable about a coupling axis thereof so as to transmit a driving force from the driving shaft to said photosensitive drum, said coupling member being capable of inclining relative to said photosensitive drum so that the coupling axis inclines relative to the drum axis; and iii) a regulating portion surrounding said coupling member to confine a range of the inclination of said coupling member, wherein said regulating portion is provided with a recess that is recessed in the mounting direction away from said drum axis, and wherein an angle between the coupling axis and the drum axis is larger when at least a part of said coupling member is in said recess that is recessed in a direction away from said drum axis than when said coupling member contacts another portion of said regulating portion.

According to another aspect of the present disclosure, there is provided a process cartridge comprising: (i) a photosensitive drum rotatable about a drum axis thereof; (ii) a rotatable developing roller configured to develop a latent image formed on said photosensitive drum; (iii) a coupling member provided at an axial end portion of said photosensitive drum and rotatable about a coupling axis thereof so as to transmit a driving force to said photosensitive drum, said coupling member being capable of inclining relative to said photosensitive drum so that the coupling axis inclines relative to the drum axis, said coupling member having (iii-i) a first end portion connected to said photosensitive drum, (iii-ii) a second end portion, and (iii-iii) a connecting portion between said first end portion and said second end portion, wherein a maximum distance from the coupling axis to an outermost surface of said connecting portion along a line perpendicular to the

9a coupling axis is less than a maximum distance from the coupling axis to an outermost surface of said second end portion along a line perpendicular to the coupling axis; and (iv) a regulating portion surrounding said coupling member to confine a range of the inclination of said coupling member, wherein said regulating portion is provided with a portion that opens in a direction away from said drum axis and away from said developing roller, and wherein an angle between the coupling axis and the drum axis is larger when at least a part of said connecting portion is in said portion that opens in a direction away from said drum axis and away from said developing roller than when said coupling member contacts another portion of said regulating portion.

These and other objects, features, and advantages of the present invention will become more apparent upon consideration of the following description of the preferred embodiments of the present invention, taken in conjunction with the accompanying drawings.

[BRIEF DESCRIPTION OF THE DRAWINGS] Figure 1 is a sectional view of a main assembly of an image forming apparatus and a cartridge according to an embodiment of the present invention.

Figure 2 is an enlarged sectional view of the cartridge.

Figure 3 is a perspective view illustrating a structure of a frame of the cartridge.

Figure 4 is a schematic perspective view of the main assembly of the apparatus.

Figure 5 is a schematic perspective view of a driving shaft of the main assembly of the apparatus.

Figure 6 is a schematic perspective view of the coupling member.

Figure 7 is an illustration showing the state in which the coupling member and the driving shaft are engaged with each other.

Figure 8 is a sectional view showing the state in which the coupling member and the driving shaft are engaged with each other.

Figure 9 is a perspective view illustrating the

coupling member.

Figure 10 is a perspective view illustrating a

spherical member.

Figure 11 is a sectional view illustrating the

coupling member and a connecting part.

Figure 12 is a perspective view illustrating

the coupling member and the connecting parts.

Figure 13 is an illustration of a drum flange.

Figure 14 is a sectional view taken along a

line S2 - S2 in Figure 13.

Figure 15 is a sectional view taken along a

line Si - Sl in Figure 13, illustrating a process of

mounting the coupling member to the drum flange.

Figure 16 is a sectional view taken along a

line Si - Sl in Figure 13, illustrating a process of

fixing the coupling member to the drum flange.

Figure 17 is a schematic perspective view of an

electrophotographic photosensitive drum unit as seen

from a driving side.

Figure 18 is a schematic perspective view of

the electrophotographic photosensitive drum unit as

seen from a non-driving side.

Figure 19 is a perspective view of a cartridge

set portion of the main assembly of the apparatus.

Figure 20 is a perspective view of a cartridge

set portion of the main assembly of the apparatus.

Figure 21 is a sectional view illustrating a

process of mounting the cartridge to the main assembly

of the apparatus.

Figure 22 is a sectional view of a drum bearing.

Figure 23 is a perspective view illustrating a

driving side of a main assembly guide.

Figure 24 is a side view illustrating a

relation between the main assembly guide and the

coupling member.

Figure 25 is a perspective view illustrating a

relation between the main assembly guide and the

coupling.

Figure 26 is a side view illustrating a

relation between the cartridge and the main assembly

guide.

Figure 27 is a perspective view illustrating a

relation between the main assembly guide and the

coupling.

Figure 28 is a side view illustrating a

relation between the main assembly guide and the

coupling.

Figure 29 is a perspective view illustrating a

relation between the main assembly guide and the

coupling.

Figure 30 is a side view illustrating a relation between the main assembly guide and the coupling.

Figure 31 is a perspective view illustrating a

process of engagement between the driving shaft and

the coupling member.

Figure 32 is a perspective view illustrating a

process of the coupling caught by the driving shaft.

Figure 33 is exploded perspective views of a

driving shaft, a driving gear, a coupling and a drum

shaft.

Figure 34 is an illustration of a coupling

operation in the process of taking the cartridge out

of the main assembly o'f the apparatus.

Figure 35 is an illustration of an end

configuration of the driving shaft.

[BEST MODE FOR CARRYING OUT THE INVENTION]

Embodiments

(General arrangement)

Referring to the accompanying drawings, the

preferred embodiments of the present invention will be

described.

Figure 1 is a sectional views of a main

assembly 1 (main assembly) and a process cartridge 2

(cartridge) of an electrophotographic image forming

apparatus according to the present embodiment. Figure

2 is an enlarged cross-sectional view of the cartridge

2. Referring to Figs. 1 - 2, a general arrangement and

an image formation process of the image forming

apparatus according to the present embodiment will be

described.

The present invention is applied to the process

cartridge itself shown in Figure 2, for example. In

addition, the present invention is applied to the

photosensitive drum unit 21 itself shown in Figure 17

(a), for example. In addition, the present invention

is applied to the electrophotographic image forming

apparatus itself shown in Figure 1, for example.

This image forming apparatus is an

electrophotographic laser beam printer with which the

cartridge 2 is detachably mountable to the main

assembly 1. When the cartridge 2 is mounted to the

main assembly 1, there is an exposure device (laser

scanner unit) 3 above the cartridge 2. A sheet tray 4

which contains a recording material (sheet material) P

which is an image formation object is provided, below

of the cartridge 2. In addition, in the main assembly

1, along the feeding direction of the sheet material P,

there are provided a pickup roller 5a, a feeding

roller 5b, a feeding roller pair 5c, a transfer guide

6, a transfer charging roller 2, a conveyance guide B,

a fixing device 9, a discharging roller pair 10, a

discharging tray 11, and so on.

Designated by 2a is a drum shutter, and when the cartridge 2 is taken out of the main assembly 1, it protects a photosensitive drum 20. The shutter 2a is in an open position in Figure 1 and Figure 2.

(Image formation process)

The outline of the image formation process will

be described. The electrophotographic photosensitive

drum (drum) 20 is rotated in a direction indicated by

the arrow R1 at a predetermined peripheral speed

(process speed) on the basis of the print start signal.

The drum 20 is rotatable about the axis (drum axis) L1,

and has a photosensitive layer as the outermost layer.

A charging roller (charging means) 12 which is

supplied with a bias voltage contacts to an outer

surface of the drum 20, and the outer surface of the

drum 20 is uniformly charged by this charging roller

12.

A laser beam L modulated correspondingly to a

serial electrical digital pixel signal of the image

information is outputted from the exposure device 3.

The laser beam L enters an inside of the cartridge 2

through an exposure window 53 of the upper portion of

the cartridge 2 to expose the outer surface of the

drum 20 scanningly to the laser beam. By this, an

electrostatic latent image corresponding to the image

information is formed on the outer surface of the drum

20. The electrostatic latent image is visualized into

a toner image with the developer T (toner) in the developing device unit 40.

The charging roller 12 is contacted to the drum

20 and charges the drum 20 electrically. The charging

roller 12 is rotated by the drum 20. The developing

device unit 40 supplies the toner to the developing

area of the drum 20 to develop the latent image formed

on the drum 20.

The developing device unit 40 feeds the toner T

out of a toner chamber 45 into a toner feed chamber 44

by the rotation of a stirring member 43. While it

rotates a developing roller 41 which is a developer

carrying member which contains a magnet roller

(stationary magnet) 41a, it forms a layer of the toner

triboelectrically charged by a developing blade 42 on

the surface of the developing roller (developing

means) 41. It forms the toner image by transferring

the toner to the drum 20 in accordance with the latent

image to visualize the latent image. While the

developing blade 42 regulates the toner amount on the

peripheral surface of the developing roller 41, it

triboelectrically charges the toner.

On the other hand, the sheet material P

contained in a lower part of the main assembly 1 is

fed from the sheet tray 4 by the pickup roller 5a, the

feeding roller 5b, and feeding roller 5c in timed

relation with the output of the laser beam L. The

sheet material P is supplied via the transfer guide 6, in the timed relation, to a transfer position formed between the drum 20 and the charging roller for the transferring 7. In the transfer position, the toner image is transferred onto the sheet material P sequentially from the drum 20.

The sheet material P onto which the toner image

has been transferred is separated from the drum 20,

and is fed to a fixing device 9 along a conveyance

guide 8. The sheet material P passes a nip formed

between a fixing roller 9a and a pressing roller 9b

which constitute the fixing device 9. It is subjected

to the pressing and heat-fixing process in the nip, so

that the toner image is fixed on the sheet material P.

The sheet material P which has the fixed toner image

is fed to a discharging roller pair 10, and is

discharged to the discharging tray 11.

On the other hand, as for the drum 20 after the

image transfer, the residual toner on the outer

surface thereof is removed by a cleaning blade

(cleaning means) 52, and it is used for the image

formation operation which starts with the charging.

The residual toner removed from the drum 20 is stored

in the waste toner chamber 52a of the photosensitive

member unit 50.

In the above described example, the charging

roller 12, the developing roller 41, the cleaning

blade 52, and so on are the process means actable on the drum 20.

(Frame structure of the process cartridge)

Figure 3 is a perspective view illustrating a

frame structure of the cartridge 2. Referring to

Figure 2 and Figure 3, the frame structure of the

cartridge 2 will be described.

As shown in Figure 2, the drum 20, the charging

roller 12, and the cleaning blade 52 are mounted to a

drum frame 51 to constitute an integral photosensitive

member unit 50.

On the other hand, a developing device unit 40

is constituted by a toner chamber 45 which contains

the toner, and a toner accommodating chamber 40a and

cover 40b which forms a toner feed chamber 44. The

toner accommodating chamber 40a and cover 40b are

connected integrally with each other by the means such

as welding.

The photosensitive member unit 50 and the

developing device unit 40 are rotatably connected

relative to each other by a connection member 54 of

the round pin.

That is, on a free end of an arm portion 55a

formed on a side cover 55 provided at each end with

respect to the longitudinal direction (an axial

direction of the developing roller 41) of developing

device unit 40 a round rotation hole 55b is provided

in parallel with the developing roller 41. The arm portion 55a is inserted into the predetermined position of the drum frame 51. The drum frame 51 is provided with an engaging hole 51a (in (a) of Figure 3, left-hand side is unshown of Figure 3) for receiving a connection member 54 co-axial with rotation hole 55b.

The connection member 54 penetrates the rotation hole

55b and the engaging hole Sla, by which, the

photosensitive member unit 50 and the developing

device unit 40 are connected with each other rotatably

about the connection member 54. At this time, the

compression coil spring 46 mounted to the base portion

of the arm portion 55a abuts to the drum frame 51 to

urge the developing device unit 40 downwardly. By this,

the developing roller 41 (Figure 2) is assuredly

forced toward the drum 20 direction. A spacing member

(unshown) is mounted to each end of the developing

roller 41 to hold the developing roller 41 with a

predetermined interval from the drum 20.

(Method for rotational force transmission process

cartridge)

Figure 4 is a perspective view of the main

assembly 1 with the open cartridge door (main assembly

cover) 109. The cartridge 2 is not mounted. Referring

to Figure 4, a rotational force transmission method to

the cartridge 2 will be described.

The main assembly 1 is provided with a guiding

rail 130 for the cartridge mounting and demounting, and the cartridge 2 is mounted to the inside of the main assembly 1 along the guiding rail 130. In this case, a driving shaft 100 of the main assembly 1 and a coupling member 150 (Figure 3, coupling) as a rotational force transmitting portion of the cartridge

2 are coupled with each other in interrelation with

the mounting operation of the cartridge 2. By this,

the drum 20 receives the rotational force from the

main assembly 1 to rotate.

The coupling member 150 is, as will be

described hereinafter, provided to the end of the drum

20, and it is pivotable in substantially all

directions relative to the axis L1 of the drum. And,

the coupling member 150 of this drum 20 can take a

rotational force transmitting angular position (first

angular position) for transmitting a rotational force

to the drum 20. In addition, it can take a pre

engagement angular position (second angular position)

inclined in the direction away from the axis Li of the

drum 20 from the rotational force transmitting angular

position. In addition, it can take a disengaging

angular position (third angular position) inclined in

the direction away from the axis Li of the drum from

the rotational force transmitting angular position.

This will be described hereinafter.

1) The driving shaft 100 Figure 5 is a

perspective view of the driving shaft 100 provided in the main assembly 1. The driving shaft 100 is coupled with drive transmission means, such as the unshown gear train provided in the main assembly 1, and with the motor. A free end portion 100a of the driving shaft 100 has a substantially semispherical surface, and has a rotational force transmitting pins 100b as the rotational force applying portion. These configurations will be described hereinafter.

2) Coupling member 150 Figure 6 is a

perspective view of the coupling member 150. The

material of the coupling member 150 is polyacetal,

polycarbonate, and PPS or the like resin material. In

order to enhance the rigidity of the coupling member

150, glass fibers, carbon fibers, and so on may be

mixed in the resin material correspondingly to the

load torque. When these materials are mixed, the

rigidity of the coupling member 150 can be enhanced.

In addition, in order to further raise the rigidity,

the metal may be inserted in the resin material, and

the whole coupling may be made with the metal and so

on

The free end of the coupling member 150 is

provided with a plurality of drive receiving

projections 150d (150d1-150d4). The drive receiving

projection 150d (150dl-l5Od4) is provided with a

rotational force receiving portion 150e (150el-150e4),

and this is provided inclinedly relative to the axis

L2 of the coupling member 150. Furthermore, the inside

of drive receiving projections 150dl - 150d4 provides

a funnel-like driving shaft receiving surface (recess)

150f. The driving shaft receiving surface 150f is in

S the form of a recess.

More particularly, , the rotational force

receiving portions 150e of the coupling member 150 are

opposed to each other and disposed interposing the

center on a phantom circle C(Figure 9) which has

Center 0 on the rotation axis of the coupling member

150 (axis L2). In the present embodiment, four

rotational force receiving portions 150el - 150e4 are

provided. The driving shaft receiving surface 150f

crosses with the rotation axis of the coupling member

150, and has an expanded part which expanded toward

the free end. The rotational force receiving portions

150e (150el-150e4) are disposed at equal intervals

along the circumferential direction of the rotation of

the coupling member 150 at the free end portion of the

expanded part.

3) Connection between driving shaft 100 and the

coupling member 150 Figure 7 illustrates the state

that the coupling member 150 and the driving shaft 100

connect with each other. Figure 8 is the sectional

view illustrating the state that the coupling member

150 and the driving shaft 100 connect with each other.

Referring to Figure 7 and Figure 8, the coupling of the driving shaft 100 and the coupling member 150 will be described.

The rotational force transmitting pins 100b of

the driving shaft 100 are in engagement with the

rotational force receiving portions 150e (150el-150e4).

Although it is not shown in Figure 7, the rotational

force transmitting pin 100b on the back side also is

in engagement with the rotational force receiving

portion 150e. In addition, the free end portion 100a

of the driving shaft 100 is in contact with the

driving shaft receiving surface 150f of the coupling

member 150. By the rotation of the driving shaft 100,

the rotational force is transmitted to the rotational

force receiving portion 150e from the rotational force

transmitting pin 100b. In addition, rotational force

receiving portion 150e is inclined relative to the

axis L2 of the coupling member 150 so that the

coupling member 150 and the driving shaft 100 attract

each other, and the assured contact is stabilized

between free end portion 100a and driving shaft

receiving surface 150f to establish the assured

rotational force transmission.

Two rotational force transmitting pins 100b as

the rotational force applying portions of the driving

shaft 100 are projected in the opposite directions

relative to each other with respect to the direction

substantially perpendicular to the axis of the driving shaft, and projects. Any one of the rotational force receiving portions 150e (150el-150e4) engages with one of the rotational force transmitting pins 100b. In addition, the other one of the rotational force receiving portions engages with the other one of rotational force transmitting pins 100b. By this, the coupling member 150 receives the rotational force from the driving shaft 100 to rotate.

The expanded part of driving shaft receiving

surface 150f of the coupling member 150 has a conical

shape, as shown in Figure 8. This conical shape has an

apex a on the rotation axis of the coupling member 150.

Figure 8 shows the state that the coupling member 150

is at the rotational force transmitting angular

position. In this state, the rotation axis L150 of the

coupling member 150 is coaxial substantially with the

axis of the drum 20. And, an apex a of the conical

shape of the driving shaft receiving surface ISOf

opposes to the free end of the driving shaft 100, and

the coupling member 150 covers the free end of the

driving shaft 100 to transmit the rotational force to

the coupling member 150. The rotational force

receiving portions 150e (150el-150e4) are disposed at

equal intervals in the circumferential direction of

the rotation of the coupling member 150.

4) Coupling and connection parts Figure 9 is a

perspective view illustrating the coupling member 150.

Figure 10 is a perspective view illustrating a

spherical member 160. Figure 11 is a sectional view

illustrating the coupling member 150 and a connection

part. Figure 12 is a perspective view illustrating the

coupling member 150 and the connection parts.

A through-hole 150r is provided adjacent to the

end 150s of the opposite side of the coupling member

150 from the rotational force receiving portion 150e.

A spherical member 160 for connecting with the

coupling member 150 has a substantially spherical

shape, and a hole for inserting the coupling member

150, and a pin 155 as will be described hereinafter

are provided. A hole 160a closed at one end is a

portion into which the end 150s of the coupling member

150 is inserted. In addition, through-hole 160b is a

portion into which the pin 155 is inserted as will be

described hereinafter, and it penetrates one-end

closed hole 160a.

As shown in Figures 11 and 12, the end 150s of

the coupling member 150 is inserted into hole 160a of

the spherical member 160, and the pin 155 is inserted

in the state that the through-hole 150r and the

through-hole 160b are aligned with each other. In the

present embodiment, the coupling member 150 and the

hole 160a are engaged with a loose-fit, the pin 155

and the through-hole 150r are engaged with a loose-fit,

and the pin 155 and the through-hole 160b are engaged with a tight-fit. Accordingly, the pin 155 and the spherical member 160 are connected integrally. This combined structure constitutes a coupling assembly 156.

When the coupling member 150 receives the

rotational force from the driving shaft 100, it

rotates about the axis L150 and the edge of through

hole 150r abuts to the pin 155. In other words, the

rotational force from the main assembly 1 is converted

to the force for rotating the pin 155 about the

rotation axis L150 through the coupling member 150.

5) Rotational force transmission to drum 20

from coupling assembly 156 Figure 13 is an

illustration of drum flange 151 (flange). Figure 14 is

a sectional view taken along a line S2-S2 in Figure 13.

Figure 15 is a sectional view illustrating a process

of attaching the coupling member 150 to the flange 151

with a view taken along a line Si-Si of Figure 13.

Figure 16 is a sectional view illustrating a process

fixing the coupling member 150 to the flange 151 with

a view taken along a line S1-S1 of Figure 13. Figure

17 is a perspective view of the electrophotographic

photosensitive drum unit 21, as seen from a driving

side (coupling member 150). Figure 18 is a perspective

view of the electrophotographic photosensitive drum

unit 21, as seen from a non-driving side (opposite end

portion).

Referring to Figure 13 and Figure 14, an example of a flange 151 for mounting the coupling member 150 will be described. Figure 13 shows the flange 151, as seen from the driving shaft 100 side.

The opening 151g (151gl-151g4) shown in Figure 13 is a

groove extended in the rotation axis direction of the

flange 151. When the coupling member 150 is mounted to

the flange 151, the pin 155 is received by any two of

this openings 151gl - 151g4. Furthermore, the

clockwisely upstream parts of the openings 151gl

151g4 is provided with rotational force transmitting

surfaces (rotational force receiving portion) 151h

(151hl-151h4). When the rotational force is

transmitted to the flange 151 from the pin 155, the

pin 155 and rotational force transmitting surface 151h

contact to each other. In addition, a space (recess

151f) is provided adjacent the center axis L151 of the

flange 151. The flange 151 has a gear 151m (Figure 15,

Figure 16, Figure 17, and Figure 18). The gear 151m

transmits the rotational force received from the

coupling member 150 driving shaft 100 to the

developing roller 41.

The recess 151f is a space surrounded by a

cylinder surface 151j (151j4-151j4), a retaining

portion 151i (151il-151i4), and an opening 151k

(151kl-151k4). The cylinder surface 151j (151j4-151j4)

is a substantial cylinder surface which is adjacent to

the opening 151g and which has a center on the axis

L151, and it is a portion of the cylinder surface

which has a diameter D151a. The retaining portion 151i

(151il-151i4) has a substantially semispherical

surface which is smoothly continuous with the

cylindrical surface 151j, and it has a radius SR151.

The opening 151k (151k1-151k4) is disposed on the

driving shaft 100 side of retaining portion 151i, and

it is an opening which has a diameter D151b.

A relation between them and the outside

dimension D160 of the spherical member 160 is as

follows (Figure 14, Figure 15).

D151b < D160 < D151a t 2xSR15lThe spherical

member 160 can be inserted into recess 151f with a gap,

but it is prevented from moving toward the opening

151k in the direction of the axis L151. A spherical

member 160 (coupling assembly 156) does not separate

from the flange 151 (process cartridge 2) under the

normal condition by this prevention.

The coupling member 150 has a gap between the

rotational force transmitting pin 155 (rotational

force transmitting portion) and the rotational force

transmitting surface (rotational force receiving

portion) 151h so that it is pivotable substantially in

all directions relative to the axis Li of the drum 20.

The pin 155 is movable relative to the rotational

force transmitting surface 151h. In this manner, the

coupling member 150 is mounted to the end of the drum

20 so that the pin 155 and rotational force

transmitting surface 151h contact with each other in

the rotational direction of the coupling member 150.

Referring to Figures 15 and 16, the process for

mounting and fixing the coupling member 150 to the

flange 151 will be described. The end 150s is inserted

in the direction of the arrow X1 into the flange 151.

Then, the spherical member 160 is placed in the arrow

X2 direction. Furthermore, the through-hole 160b of

the spherical member 160 and the through-hole 150r of

end 150s are co-axially aligned, and the pin 155 is

inserted in the direction of the arrow X3 after that.

The pin 155 penetrates the through-hole 160b and the

through-hole 150r. Since the inner diameters of

through-hole 160b and through-hole 150r are smaller

than a diameter of the pin 155, the frictional force

occurs between the pin 155 and through-hole 160b and

between the pin and through-hole 150r. The

interference is about 50 micrometers in the present

embodiment.

By this, at the time of the ordinary use, the

pin 155 is retained assuredly, and the coupling

assembly 156 is maintained integral.

The coupling assembly 156 is moved in an X4

direction, and the spherical member 160 is contacted

or approached to the retaining portion 151i.

Then, the retention member 157 is inserted in the arrow X4 direction to fix to the flange 151. Since the play (gap) is provided relative to the spherical member 160, the coupling member 150 can change the orientation.

Referring to Figure 17 and Figure 18, the

structure of electrophotographic photosensitive drum

unit 21 (photosensitive drum unit) will be described.

The flange 151 which is provided with the coupling

assembly 156 is fixed to the end side of the drum 20

so that drive receiving projection 150d is exposed.

Non-driving side drum flange 152 is fixed to the other

end side of the drum 20. The fixing method may be

crimping, bonding, welding or the like. The

photosensitive drum unit 21 is supported rotatably by

the drum frame 51 in the state that the driving side

is supported by the bearing member 15, and the non

driving side is supported by the photosensitive drum

unit supporting pin 202. The non-driving side is

supported rotatably in hole 152a of drum flange 152 by

the pin 202.

In the present embodiment, the coupling member

150 is mounted to the end of the drum 20 through the

flange 151, and is pivotable and revolvable in all

directions substantially, relative to the axis L1 of

the drum 20.

As has been described hereinbefore, the

rotational force from the motor (unshown) of the main assembly 1 rotates the driving shaft 100 through the drive transmitting means (unshown), such as the gear of the main assembly 1. The rotational force thereof is transmitted to the cartridge 2 through this the coupling member 150. Furthermore, the rotational force is transmitted through the pin 155 from the coupling member 150 to the flange 151, and it is transmitted to the drum 20 integrally fixed to the flange 151.

Designated by 151c is a gear, and the rotational force

received by the coupling member 150 from the driving

shaft 100 is transmitted to the developing roller 41

(Figure 2). The gear 151c is integrally molded with

the flange 151.

(Mounting and demounting structure of the cartridge

2)

The mounting guide for mounting the cartridge 2

to the main assembly 1 will be described. The mounting

means 130 of the present embodiment includes the main

assembly guides 130R1, 130R2, 130L1, 130L2 provided in

the main assembly 1. They are provided on the right

and left internal surfaces of the cartridge mounting

space (cartridge set portion 130a) provided in the

main assembly 1. (Figure 19 shows the driving side and

Figure 20 shows the non-driving side). Correspondingly

to the driving side of the cartridge 2, the main

assembly guide 130Ri, 130R2 extends along the mounting

direction of the cartridge 2. On the other hand, correspondingly to the non-driving side of the cartridge 2, the main assembly guides 130L1, 130L2 extend along the mounting direction of the cartridge 2.

The main assembly guides 130R1, 130R2 and the main

assembly guides 130L1, 130L2 are opposed to each other.

In mounting the cartridge 2 to the main assembly 1,

the cartridge guides as will be described hereinafter

are guided by the guides 130R1,130R2,130L1,130L2 in

order to mount the cartridge 2 to the main assembly 1,

the cartridge door 109 which is openable and closable

relative to the main assembly 1 is opened. The

mounting relative to the main assembly 1 of the

cartridge 2 is completed by closing the door 109. Also,

in taking the cartridge 2 out of the main assembly 1,

the door 109 is opened. These operations are carried

out by the user.

The mounting guides of the cartridge 2 and the

positioning portion relative to the main assembly 1

will be described. In the present embodiment, the

outer periphery 158a of the outside end of the bearing

member 158 functions also as a cartridge guide 140R1.

The cylindrical portion 51a of the drum frame

functions also as the cartridge guide 140L1.

Designated by 158h is a bearing, and supports the drum

20 rotatably (Figure 22 (C), Figure 26). The bearing

158h is provided in a bearing member 158.

One longitudinal end portion (driving side) of the drum frame 51 is provided with a cartridge guide

140R2 substantially above the cartridge guide 140R1.

The other longitudinal end portion (non-driving side)

is provided with a cartridge guide 140L2 substantially

above the cartridge guide 140L1.

The one longitudinal end portion of the drum 20

is provided with the cartridge side guides 140R1,

140R2 outwardly projected from the drum frame 51. The

other longitudinal end portion is provided with the

cartridge side guides 140L1, 140L2 which outwardly

projects from the drum frame 51. The guides 140R1,

140R2, 140L1, 140L2 outwardly project along the

longitudinal direction. The guides 140R1, 140R2, 140L1,

140L2 project from the drum frame 51 along the axis L1

of the drum 20. When the cartridge 2 is mounted to the

main assembly 1, and when the cartridge 2 is demounted

from the main assembly 1, the guide 140R1 is guided by

the guide 130R1, and the guide 140R2 is guided by the

guide 130R2. When the cartridge 2 is mounted to the

main assembly 1, and when the cartridge 2 is demounted

from the main assembly 1, the guide 140L1 is guided by

the guide 130L1, and the guide 140L2 is guided by the

guide 130L2. Thus, the cartridge 2 is moved in the

direction substantially perpendicular to the axial

direction L3 of the driving shaft 100 and is mounted

to the main assembly 1, and it is moved and demounted

from the main assembly 1 in the direction. The cartridge guides 140R1, 14CR2 are molded integrally with the second frame 118 in the present embodiment.

However, separate members may be used as the cartridge

guides 140R1, 140R2.

The mounting operation of the process cartridge

will be described. Referring to Figure 21 , the

mounting operation of the cartridge 2 relative to the

main assembly 1 will be described. Figure 21 shows the

mounting process. Figure 21 is the sectional view

taken along a line S9-S9 in Figure 19.

As shown in (a) of Figure.21, the user opens

the door 109, and mounts the cartridge 2 removably

relative to the cartridge mounting means 130 (set

portion 130a) provided in the main assembly 1.

As shown in (b) of Figure 21, when the

cartridge 2 is mounted to the main assembly 1, the

cartridge guides 140R1,140R2 are guided by the main

assembly guides 130R1,130R2 in the driving side. The

cartridge guides 140L1, 140L2 ((b) of Figure 3) are

guided along the main assembly guide 130L1, 130L2

(Figure 20) also in the non-driving side.

Referring to (a), (b) and (c) of Figure 22, the

detailed description will be made as to the state

until the cartridge 2 is inserted to the main assembly

guide (130R1), and as to the configuration of the drum

bearing member 158 as the regulating portion for

regulating the coupling member 150.

As described above, the coupling member 150 is

pivotable in photosensitive drum unit 21. Therefore,

when the cartridge 2 is outside main assembly 1, it

normally inclines downward by the gravity.

In Figure 22, (a) is a perspective view in the

neighborhood of the drum bearing member of the

cartridge 2, and the coupling is omitted for better

understanding. (b) of Figure 22 is a side view of the

cartridge 2. (c) of Figure 22 is a sectional view of

the cartridge 2 taken along a line S10 of (b) of

Figure 22, wherein the orientations of the axis Li of

photosensitive drum unit 21 (drum 20), and the

inclined axis L2 of the coupling member 150 are shown.

The configuration of the drum bearing member

158 will be described using (a) of Figure 22. The drum

bearing member 158 is provided with a regulating

portion 170 for regulating the motion of the coupling

member 150 around the hole 158f penetrated by the

coupling member 150. More particularly, the bearing

member 158 is provided with the regulating portion 170.

This regulating portion 170 regulates the inclination

angle of the coupling member 150 so that the

inclination angle of the coupling member 150 relative

to the axis Li of the drum 20 in the pre-engagement

angular position is the larger than the inclination

angle in other angular position (rotational force

transmitting angular position, pre-engagement angular position). More particularly, the regulating portion

170 regulates the inclination angle of the coupling

member 150 so that the angle of the inclination of the

coupling member 150 by the weight is smaller then the

angle when the coupling member 150 takes the pre

engagement angular position (second angular position).

Here the rotational force transmitting angular

position is a first angular position. The pre

engagement angular position is a second angular

position. The disengaging angular position is a third

angular position.

The drum bearing member 158 is provided with a

hole 150f. The coupling member 150 is pivotable in the

range surrounded in hole 150f. Along with the outer

periphery of hole 150f, a first arc part 170a which

has an inclination regulating portion 170g is provided.

The coupling member 150 penetrates this hole 150f at

the time of the assemblying operation. In the state

that the cartridge 2 is outside the main assembly 1,

an inclination regulating portion 170g is provided

below the hole 150f. The inclination regulating

portion 17og regulates the inclination angle of the

coupling member 150 in the state that the cartridge 2

is outside main assembly 1. A projection regulating

portion 170c projected outside in the axis Ll

direction from a part of edge of hole 158f is provided

with a second arc part 170d and a flat surface portion

170e connected with the second arc part 170d. The

projection regulating portion 170c constitutes an

inclination regulating portion 140Rla as will be

described hereinafter. The inclination regulating

portion 140Rla regulates the inclining direction of

the coupling member 150 between the left side from the

upper surface. Therefore, the coupling member 150 can

be freely inclined only in the mounting direction (X4)

substantially. The inclination regulating portion

140Rla will be described hereinafter referring to

Figure 24 and Figure 30.

As shown in (c) of Figure 22, in the state that

the cartridge 2 is outside main assembly 1, the axis

L2 of the coupling member 150 is inclined to the

position where the coupling member 150 is held by

inclination regulating portion 170g of the regulating

portion 170. More particularly, , an intermediate part

150c of the coupling member 150 contacts to

inclination regulating portion 170g to be regulated in

the inclination angle (Figure 22 (C)). The inclination

regulating portion 170g holds the intermediate part

150c of the coupling member 150 until the coupling

member 150 is guided by the main assembly guide 130R1,

after the cartridge 2 is inserted into the main

assembly 1. In other words, it regulates the

inclination angle of the coupling member 150.

Therefore, the inclination regulating portion 170g is not extended over the entire area in the circumferential direction of the hole 150f. The a part of the neighborhood of hole 150f is provided with a projection 170b for making larger the inclination angle of the coupling member 150 than the inclination angle in the other neighborhood of hole 150f. The projection 170b projects in the radial direction

(radial direction) of hole 150f from the circumference

of hole 150f. The projection 170b regulates the

inclination angle of the coupling member 150 at the

position remoter than the projection the regulating

portion 170c and the inclination the regulating

portion 170g with respect to the radial direction from

the axis Ll of the drum 20 (Figure 29 (a)). Figure 29

(a) shows the state that the coupling member 150 is

regulated by the projection 170b in the inclination

angle. In Figure 22 (c), the driven portion 150a of

the coupling member 150 is illustrated by the broken

lines. The inclination angle of the coupling member

150 is regulated by the inclination regulating portion

170g at the inclination angle alpha 8. By this, in

mounting the cartridge 2 to the main assembly 1, the

coupling member 150 is transferred to the inserting

portion 130R2 with a small impact, without interfering

with the inserting portion 130R2 of the main assembly

guide 130. The coupling member 150 is elastically

urged by a slider 131 until it is positioned to the main assembly 1. The coupling member 150 is guided to the projection 170b, while abutting to the second arc part 170d and the flat surface portion 170e of the projection regulating portion 170c. Before contacting the coupling member 150 to the driving shaft 100, it takes the pre-engagement angular position. Therefore, the coupling member 150 can be engaged assuredly and smoothly with the driving shaft 100. The coupling member 150 receives an external force (second external force) from the slider 131.

When the cartridge 2 is further inserted in the

arrow X4 direction, the driving shaft 100 and the

coupling member 150 engage with each other, and

subsequently the cartridge 2 is mounted to the

predetermined position (set portion 130a) (setting).

In other words, the cartridge guide 140R1 contacts to

positioning portion 130RIa of the main assembly guide

130R1, and the cartridge guide 140R2 contacts to

positioning portion 130R2a of the main assembly guide

130R2. In addition, the cartridge guide 140Ll contacts

to the positioning portion 13OLla (Figure 20) of the

main assembly guide 13OL1, and, the cartridge guide

140L2 contacts to the positioning portion 130L2a of

the main assembly guide 130L2. Since the situation is

substantially symmetrical, the illustration is omitted

for simplicity. In this manner, the cartridge 2 is

removably mounted to set portion 130a by the mounting means 130. In other words, the cartridge 2 is mounted to the main assembly 1 in place. And, in the state that the cartridge 2 is set to the set portion 130a, the engagement between the driving shaft 100 and the coupling member 150 is established. More particularly, the coupling member 150 takes the rotational force transmitting angular position as will be described hereinafter. When the cartridge 2 is mounted to the set portion 130a, the image forming operation is enabled. When the cartridge 2 is set to the predetermined position as described above, the pressing receptor portion 140Rlb ((a) of Figure 3) of the cartridge 2 receives an urging force from the urging spring 188R (Figure 19). The pressing receptor portion 140Llb ((b) of Figure 3) of the cartridge 2 receives the urging force by the urging spring 188L

(Figure 20). By this, the cartridge 2 (drum 20) is

accurately positioned relative to the transfer roller,

the optical means, and so on of the main assembly 1.

In this manner, the cartridge 2 is provided

with the cartridge guides 140R1, 140R2, 140L1, 140L2

guided in the direction perpendicular to the direction

of the axis L1 of the drum 20. By this, the cartridge

2 is mounted to the main assembly 1, while moving in

the direction substantially perpendicular to the axis

L3 of the driving shaft 100. The cartridge 2 is

demounted from the main assembly 1 in the same direction.

As described above, the regulating portion 170

is provided around the coupling member 150 in the

orthogonality direction substantially perpendicular to

the axis Ll of the drum 20. More particularly, in the

regulating portion 170, a portion of the intermediate

part 150c of the coupling member 150 is surrounded

with a gap so that the coupling member 150 can be

revolved. As has been described hereinbefore, the

regulating portion 170 is provided with a first arc

part 170a and the projection 170b which projects in

the orthogonality direction continuing with the first

arc part 1la. The inclination angle of Lhe coupling

member 150 inclined by the weight is regulated by the

first arc part 158a, and the projection 158b regulates

the inclination angle of the coupling member 150 in

the pre-engagement angular position.

In this manner, when the coupling member 150

inclines by the weight thereof, the inclination angle

of the coupling member 150 is regulated by the

inclination regulating portion 170g of the first arc

part 158a contacting to the intermediate part 150c.

The projection 170b regulates the inclination angle of

the coupling member 150 in the pre-engagement angular

position.

In the present embodiment, the inclination

angle in the pre-engagement angular position is about

30 degrees, and the inclination angle regulated by

first arc part 158a is about 20 degrees (in Figure 22

(c) alpha 8). However, the present invention is not

limited to this angle, but another inclination angle

may be selected properly by one skilled in the art.

The inclination angle of the coupling member 150 is

regulated by the first arc part 120a. In other words,

in the case where the inclination angle of the

coupling member 150 is regulated, the inclination

angle of the coupling member 150 is regulated so that

it is smaller than the inclination angle when the

coupling member 150 is at the pre-engagement angular

position (second angular position). More specifically,

in the radial direction from the axis Ll, the position

where the projection 170b regulates the inclination

angle of this the coupling member 150 is set at a

remote position from the position where the first arc

part 158a regulates the inclination angle of this the

coupling member 150.

Here, the angle when the coupling member 150

inclines by the weight is the inclination angle of the

coupling member 150 when the user holds a gripper T

(Figure 3) and carries the cartridge 2. More

particularly, it is the inclination angle until the

coupling member 150 is guided by the main assembly

guide 130R1. In this case, the inclination angle of

the coupling member 150 is regulated by first arc part

170a (inclination regulating portion 170g).

The predetermined part of the first arc part

170a for regulating the inclination angle of the

coupling member 150 which inclines by the weight, and

the projection regulating portion 170c are opposed to

each other interposing the center 0.

The first arc part 170a is provided with a

projection regulating portion 170c which projects in

the axial direction from the first arc part. The

regulating portion 170 has a second arc part 170d

which has the radius the same as the first arc part

170a, and a flat surface portion 158e extended

continuing with the second arc part toward the side

which has the projection 170a. When the coupling

member 150 receives the external force (second

external force) from the main assembly 1, the coupling

member 150 is guided by the external force to the

projection 170b along the second arc part 158d and the

flat surface portion 158. By this, the coupling member

150 takes the pre-engagement angular position. The

external force (second external force) is the urging

force applied to the coupling member 150 by the slider

131.

As has been described hereinbefore, before the

mounting to the main assembly 1, the regulating

portion 170 prevents the coupling member 150 from

inclining in unnecessary directions. By this, the size with respect to the longitudinal direction of the main assembly 1 is reducible. When the cartridge 2 is mounted to the main assembly 1, the cartridge 2 can be smoothly mounted to the main assembly 1. Here, the unnecessary directions are the directions other than the pre-engagement angular position.

Here, the process cartridge 2 using the present

embodiment has the following structures (i) - (iv).

i) an electrophotographic photosensitive drum

20 rotatable about an axis and having a photosensitive

layer at its peripheral surface.

ii) process means (charging roller 12,

developing roller 41, cleaning blade 52) actable on

the drum 20.

iii) a coupling member 150 engageable with the

rotational force applying portion to receive an

external force (first external force) for rotating the

drum 20, the coupling member 150 being capable of

taking a rotational force transmitting angular

position (first angular position) for transmitting the

external force (first external force) for rotating the

drum 20 to the drum 20, a pre-engagemenL angular

position (second angular position) in which the

coupling member is inclined away from the axis Ll of

the drum 20 from the rotational force transmitting

angular position (first angular position) and a

disengaging angular position (third angular position) in which the coupling member is inclined away from the axis Li of the drum 20 from the rotational force transmitting angular position (first angular position).

Here, the external force (first external force)

is a rotational force which is received by the

coupling member 150 from the driving shaft 100.

iv) a regulating portion 170 for regulating an

inclination angle of the coupling member such that

downward inclination (by the gravity) angle of the

coupling member 150 is smaller than an inclination

angle of the coupling member when the coupling member

is at the pre-engagement angular position (second

angular position).

The regulating portion 170 surrounds the

coupling member 150 in a perpendicular direction

perpendicular to the axis LI of the drum 20, and the

regulating portion is provided with a first arcuate

portion 170a and a projected portion 170b projecting

in the perpendicular direction continuing from the

first arcuate portion 170a, and wherein the first

arcuate portion 170a (inclination regulating portion

170g) regulates the downward inclination of the

coupling member 150, and the projected portion 170b

regulates the inclination angle of the coupling member

in the pre-engagement angular position (second angular

position).

With such structures, in the present embodiment, when the cartridge 2 is inserted into the main assembly 1, the cartridge 2 can be smoothly inserted into the main assembly 1, without the coupling member

150 interfering with the other structure in the main

assembly 1. More particularly, the insertion to the

main assembly 1 of the cartridge 2 is smooth.

The first arc part 170a is provided with the

projection regulating portion 170c which projects in

the axial direction from the first arc part 170a. The

projection regulating portion 170c has the second arc

part 170d which has the radius the same as the first

arc part 170a, and the flat surface portion 170e

extended toward the projection 170b continuing with

the second arc part 170d. When the coupling member 150

receives a second external force different from the

external force (first external force), the coupling

member 150 is elastically urged by the second external

force to move along the second arc part 170d and flat

surface portion 170e. The coupling member 150 is

guided to projection 170a. By this, the coupling

member 150 takes the pre-engagement angular position

(second angular position).

With such a structure, in the present

embodiment, when the coupling member 150 engages with

the driving shaft 100 the engagement is assuredly

established between the coupling member 150 and the

driving shaft 100. The coupling between the cartridge

2 and the main assembly 1 is smoothly establishable.

The coupling member 150 is provided with the

driving shaft receiving surface (recess) 150f co-axial

with the axis L2 of the coupling member 150. The

recess has the expanded part which expands toward the

free end thereof. With such a structure, the coupling

member 150 can engage and disengage smoothly relative

to the driving shaft 100. The coupling member 150 can

stably receive the rotational force from the driving

shaft 100.

The rotational force receiving portions 150e of

the coupling member 150 is disposed at equal intervals

along the rotational direction of the coupling member

150 at the free end side of the expanded part. The

rotational force receiving portion 150e is on the

phantom circle C which has the center 0 on the axis L2

(Figure 9), interposing the center 0. With such a

structure, the coupling member 150 can receive the

rotational force with proper balance from the driving

shaft 100.

The expanded part has a conical shape. The

conical shape has the apex thereof on the axis L2.

With such a structure, the exact positioning

between the coupling member 150 and the driving shaft

100 is accomplished.

.The coupling member 150 is provided to the end

of the drum 20 substantially revolvably around the axis L1. More particularly, it is movable (pivotable) substantially in all directions relative to the axis

Ll.

With such a structure, the coupling member 150

is engageable and disengageable relative to the

driving shaft 100 irrespective of the phase of the

driving shaft 100.

Even when the axis L2 is somewhat deviated from

the axis L3 of the driving shaft 100, the coupling

member 150 can receive the rotational force smoothly.

The cartridge 2 has the guide portion

(cartridge guides 140R1, 140R2, 140L1, 140L2) guided

in the direction perpendicular to the axis Li

direction of the drum 20. By this, the cartridge 2 is

mountable and demountable relative to the main

assembly 1 in the direction substantially

perpendicular to the axis L3 of the driving shaft 100.

Here, the photosensitive drum unit 21, as will

be described hereinafter, is the structure except for

the process means of the structure described above in

ii).

Between the cartridge 2 and the apparatus main

assembly 1, in order to mount and demount the

cartridge 2 smoothly, small gaps are provided. More

specifically, the small gaps are provided $ between

the guide 140R1 and the guide 130R1 with respect to

the longitudinal direction, between the guide 140R2 and the guide 130R2 with respect to the longitudinal direction, between the guide 140L1 and the guide 130L1 with respect to the longitudinal direction, and between the guide 140L2 and the guide 130L2 with respect to the longitudinal direction. Therefore, at the time of the mounting and demounting of the cartridge 2 relative to the apparatus main assembly 1, the whole cartridge 2 can slightly incline within the limits of the gaps. For this reason, the perpendicularity is not meant strictly. However, even in such a case, the present invention is accomplished with the effects thereof. Therefore, the term "perpendicular substantially" covers the case where the cartridge slightly inclines.

Standing-by portions 150k are provided between

the projections 150d. The intervals between the

adjacent projection 150d are larger than the outer

diameter of pin 100b so that they can accept the

rotational force transmitting pins (rotational force

applying portion) 100b of the driving shaft 100

provided in the main assembly 1. The portions between

the adjacent projections provide standing-by portions

150k. When the rotational force is transmitted from

the driving shaft 100 to the coupling member 150,

transmission pin 100b is positioned in any of

standing-by portions 150k (Figure 24).

Designated by 150a is a coupling side driven portion for receiving the rotational force from pin

100b. Designated byl5Ob is a coupling side driving

portion for engaging with the rotational force

transmitting portion 155 and for transmitting the

rotational force to the drum shaft. Designated by 150c

is the intermediate part 150c which connects driven

portion 150a and driving portion 150b relative to each

other (Figure 32 (a)).

Another means for inclining the axis L2 of the

coupling member 150 relative to the drum axis Li will

be described. Figure 23 is a perspective view

illustrating the driving side of the main assembly 1.

Referring to Figure 23, the main assembly guide and

the coupling urging means will be described. According

to this embodiment, even if the frictional force is

increased by rubbing of the intermediate part 150c or

the main assembly guide, the coupling member 150

inclines assuredly to the pre-engagement angular

position. The main assembly guide 130R1 has a guide

surface 130Rlb for guiding the cartridge 2 through the

cartridge guide 140R1 (Figure 3), a guide rib 130Rlc

for guiding the coupling member 150, and a cartridge

positioning part 130Rla. The guide rib 130Rlc is

provided on the mounting locus of the cartridge 2. The

guide rib 130Rlc is extended to the front side of the

driving shaft 100 with respect to the cartridge

mounting direction. The rib 13ORid provided adjacent the driving shaft 100 has such a height as is free of interference when the coupling member 150 engages.

A part of rib 130RIc is cut away. The main

assembly guide slider 131 is mounted on rib 130Rlc

slidably in the direction of arrow W. The slider 131

is pressed by the elastic force of the urging spring

132 (Figure 24). In this state, the slider 131

projects beyond the guide rib 130RIc.

The slider 131 applies an urging force as the

external force (second external force) to the coupling

member 150. More particularly, the slider 131 applies

the urging force to the coupling member 150 as the

external force (second external force).

The main assembly guide 130R2 has a guide

portion 130R2b and a cartridge positioning part 130R2a

for guiding a part of drum frames 51, and determining

the orientation at the time of the mounting of the

cartridge 2.

Referring to Figures 24 - 26, the relation

among the main assembly guides 130R1, 130R2, the

slider 131, and the cartridge 2 during the mounting

operation of the cartridge 2 will be described. Figure

24 is a side view as seen from the driving shaft 100

(Figure 19) side of the main assembly, and Figure 25

is a perspective view thereof. Figure 25 is a Z-Z

sectional view of Figure 24.

In the driving side, the cartridge 2 moves in the state that the cartridge guide 140R1 contacts the guiding surface 130R1b. At this time, the intermediate part 150c is spaced by nl from guide rib 130Ric.

Therefore, a force is not applied to the coupling

member 150. The coupling member 150 is regulated by

regulating portion 140Rla over the upper surface and

the left side. Therefore, the coupling member 150 can

incline freely substantially only toward the mounting

direction (X4).

Referring to Figures 27 - 30, movement of the

slider 131 to the retracted position from the urging

position in the contacted state of the coupling member

150 to the slider 131, will be described. Figure 27

Figure 28 show the state that the coupling member 150

contacts the apex 131b of the slider 131, that is, the

state that the slider 131 has moved to the retracted

position. By the entrance of the coupling member 150

pivotable only to the mounting direction (X4), the

intermediate part 150c, and the inclined surface 131a

of the projection of the slider 131 (Figure 29)

contact with each other. By this, the slider 131 is

depressed to the retracted position.

Referring to Figures 29 - 30, the operation

after the coupling member 150 rides over the apex 131b

of the slider 131 will be described. Figures 29 - 30

show the state after the coupling member 150 rides

over the apex 131b of the slider 131.

When the coupling member 150 rides over the

apex 131b, the slider 131 tends to return from the

retracted position to the urging position by the

elastic force of the urging spring 132. In this case,

a part of the intermediate part 150c of the coupling

member 150 receives a force F from the inclined

surface 131c of the slider 131. More particularly, the

inclined surface 131c functions as a force applying

portion, and a part of a intermediate part 150c

functions as the force receiving portion 150p. The

force receiving portion 150p is provided in the

upstream side with respect to the cartridge mounting

direction of intermediate part 150c. Therefore, the

coupling member 150 can be inclined smoothly. The

force F is divided into component forces El and E2.

The upper surface of the coupling member 150 is

confined by the regulating portion 140Rla. A part of

regulating portion 140Rla is formed as a flat surface

portion 158e ((a) of Figure 22), and the flat surface

portion 158e is substantially parallel with or

slightly inclined relative to the mounting direction

X4. Therefore, the coupling member 150 is inclined

toward the mounting direction (X4) by the component

force F2. In other words, the coupling member 150

inclines toward the pre-engagement angular position.

By this, the coupling member 150 becomes engageable

with the driving shaft 100.

As described above, the main assembly 1 is

provided with a slider 131 which functions as the

urging member which is movable between the urging

position and the retracted positions retracted from

the urging position and which is effective to apply

the external force. When the cartridge 2 is mounted to

the main assembly 1, the slider 131 contacts the

entering cartridge 2, is once retracted from the

urging position to the retracted position, and

thereafter, returns to the urging position. The

coupling member 150 is urged by the elastic force of

the slider 131. By this, it is moved along the second

arc part 158d and flat surface portion 158e, and is

guided to the projection, so that the coupling member

150 takes the pre-engagement angular position.

the coupling member 150 has a rotational force

receiving portion 150e and a rotational force

transmitting portion 155 for transmitting a rotational

force to the drum 20, and has an intermediate part

(connecting portion) 150c of a cylindrical shape

between rotational force receiving portion 150e and

the rotational force transmitting portion 155. When

the cartridge 2 is moved in the direction

substantially perpendicular to the driving shaft 100,

the intermediate part 150c contacts the fixed portion

(main assembly guide 130R1) provided in the main

assembly to take the pre-engagement angular position.

The driving shaft 100 transmits a rotational

force as the external force (first external force) to

the coupling member 150. The driving shaft 100 applies

the rotational force as the external force (first

external force) to the coupling member 150.

In the foregoing embodiments, the intermediate

part 150c receives the force to incline the coupling

member 150. However, the present invention is not

limited to this example. For example, a portion other

than the intermediate part 150c may contact with the

slider 131, if it is pivotable when the coupling

member 150 receives the force from the slider 131 of

the main assembly 1,

(Operation of the coupling member)

The coupling engaging operation and the drive

transmission will be described. The coupling member

150 and the driving shaft 100 engage with each other

immediately before or simultaneously when the coupling

2 is set to the predetermined position or immediately

before the cartridge 2 is positioned to the

predetermined position of the main assembly 1. The

engaging operation of this the coupling member 150

will be described referring to Figure 31 and Figure 32.

Figure 31 is a perspective view illustrating the major

parts of the driving shaft 100 and the driving side of

the cartridge 2. Figure 32 is a longitudinal sectional

view, as seen from the bottom of the main assembly.

[Embodiment]

As shown in Figure 32, in the mounting process

of the cartridge 2, the cartridge 2 is mounted to the

main assembly 1 in a direction (direction indicated by

the arrow X4) substantially perpendicular to an axis

L3 of a driving shaft 100. As for the coupling member

150, the axis L2 thereof inclines toward the

downstream side with respect to the mounting direction

relative to the drum axis Li beforehand as the pre

engagement angular position ((a) of Figure 31, (a) of

Figure 32). By this inclination of the coupling member

150, the free end position 15OAl is nearer to the drum

axial direction Li than the free end 100c3 of a

driving shaft to the body of the drum 20 with respect.

In addition, the free end position 150A2 is nearer to

the pin 100b than the free end 100c3 of the driving

shaft (Figure 32 (a)).

First, the free end position 150A1 passes by

the free end 100c3 of the driving shaft. Thereafter,

the conical driving shaft receiving surface 150f or

the driven projection 150d contacts to the free end

portion 180b of the driving shaft 100, or the

rotational force drive transmission pin 100b. Here,

the driving shaft receiving surface 150f and/or the

projection 150d is the cartridge side contact portion.

In addition, the free end portion 100c3 and/or the pin

100b is the main assembly side engaging portion. In response to the movement of the cartridge 2, the coupling member 150 inclines (Figure 32 (c)) so that the axis L2 substantially co-axial with the axis Li.

Finally, when the position of the cartridge 2 is

determined relative to the main assembly 1, the

driving shaft 100 and the drum 20 are substantially

co-axial with each other. More particularly, in the

state that this cartridge side contact portion of the

coupling member 150 is in contact with the main

assembly side engaging portion, the cartridge 2 is

inserted into the main assembly 1. By this insertion,

the coupling member 150 is pivoted to the rotational

force transmitting angular position from the pre

engagement angular position so that the axis L2

substantially co-axial with the axis Ll. In this

manner, the coupling member 150 and the driving shaft

100 are engaged with each other (Figure 31 (b), Figure

32 (d)).

More particularly, in the state that the

coupling member 150 is at the rotational force

transmitting angular position, the rotation axis L2 of

the coupling member 150 is substantially co-axial with

the axis Ll of the drum 20. In addition, in the state

that the coupling member 150 is in the pre-engagement

angular position, it inclines relative to the axis Ll

of the drum 20 so that the downstream side in the

mounting direction for mounting the cartridge 2 to the main assembly 1 can pass by the free end of the driving shaft 100.

As described above, at the time of mounting the

cartridge 2 to the main assembly 1, while moving it in

the direction perpendicular to the axis Ll of the drum

20, the coupling member 150 moves to the rotational

force transmitting angular position from the pre

engagement angular position. By this, the coupling

member 150 is opposed to the driving shaft 100.

More particularly, the coupling member 150 has

the driving shaft receiving surface 150f on the

rotation axis. When mounting the cartridge 2 to the

main assembly 1, the cartridge 2 is moved in the

direction substantially perpendicular to the axis Ll

of the drum 20. In response to this movement, the

coupling member 150 pivots to the rotational force

transmitting angular position from the pre-engagement

angular position so that a part of the coupling member

positioned at the downstream side as seen in the

direction of mounting the cartridge 2 to the main

assembly 1 is permitted to circumvent the driving

shaft 100. And, in the state that the coupling member

150 is in the rotational force transmitting angular

position, the driving shaft receiving surface 150f

covers the free end of the driving shaft 100. In this

state, the rotational force receiving portion 150e of

the coupling member 150 engages with the rotational force applying portion 100b which projects in the direction substantially perpendicular to the axis L3 of the driving shaft 100 in the free end portion of the driving shaft 100 in the rotational direction of the coupling member 150. By this, the coupling member

150 receives the rotational force from the driving

shaft 100 to rotate.

As has been described hereinbefore, the

coupling member 150 is mounted for inclining motion

relative to the axis L1. And, in response to the

mounting operation of the cartridge 2, by the pivoting

of the coupling member 150, it can be engaged with the

driving shaft 100.

Similarly to embodiment 1, the engaging

operation of the coupling member 150 described above

is possible regardless of the phases of the driving

shaft 100 and the coupling member 150.

In this manner, in this embodiment, the

coupling member 150 is mounted to the end of the drum

substantially revolvably and swingably about the axis

L1. The motion of the coupling shown in Figure 32 may

include the revolution.

In this embodiment, the revolution of the

coupling member 150 is not a rotation of the coupling

per se around the axis of the coupling L2 but the

rotation of the inclined axis L2 around the axis of

the drum 20 Li. However, within the limits of the play or the gap provided positively, the rotation of the coupling per se around the axis L2 is not excluded.

The coupling member is provided to an end of

the electrophotographic photosensitive drum 20 and is

capable of tilting relative to the axis Ll of the

electrophotographic photosensitive drum 20

substantially in all directions. By doing so, the

coupling member 150 can pivot smoothly between the

pre-engagement angular position and the rotational

force transmitting angular position and between the

rotational force transmitting angular position and the

disengaging angular position.

Substantially all directions is intended to

mean that coupling can pivot to the rotational force

transmitting angular position irrespective of the

phase at which the rotating force applying portion

stops.

In addition, the coupling can pivot to the

disengaging angular position irrespective of the phase

at which the rotating force applying portion stops.

A gap is provided between the pin 155 (rotating

force transmitting portion) and the rotating force

receiving member (Figure 13) 155h so that the coupling

member is capable of tilting relative to the axis Ll

of the electrophotographic photosensitive drum 20

substantially in all directions. The coupling member

150 is provided at an end of the electrophotographic photosensitive drum 20. The coupling is mounted to the end of the drum in this manner. The coupling is capable of inclination substantially in all directions relative to the axis Li.

Referring to Figure 33, the description will be

made about the rotational force transmitting operation

at the time of rotating the drum 20. The driving shaft

100 rotates with the drum driving gear 181 in the

direction of X8 in the Figure by the rotational force

received from the motor (unshown). The gear 181 is the

helical gear and the diameter thereof in the present

embodiment is approx. 80mm. The pin 100b integral with

the driving shaft 100 contacts to any two of the four

receiving surfaces 150e (rotational force receiving

portions) of the coupling member 150. The coupling

member 150 rotates by the pin 100b pushing the

receiving surfaces 150e. In addition, the rotational

force transmitting pin 155 (in Figure 11, the coupling

side engaging portion, the rotational force

transmitting portion) contacts the coupling member 150

to the rotational force transmitting surface (in

Figure 13, rotational force receiving portion) 151h

(151h1, 151h2). By this, the coupling member 150 is

coupled with the drum 20 so that the rotational force

can be transmitted. Therefore, the drum 20 rotates

through the flange 151 by the rotation of the coupling

member 150.

In addition, in the case where the axis Li and

the axis L2 are somewhat deviated from concentric

state, the coupling member 150 inclines to a slight

degree. By this, the coupling member 150 can rotate

without applying the large load to the drum 20 and the

driving shaft 100. For this reason, no highly precise

adjustment is required in the assembly operations of

the driving shaft 100 and the drum 20. Therefore, the

cost is reduced.

The operation of the coupling member 150 at the

time of taking the cartridge 2 out of the main

assembly 1 will be described. Figure 34 is a

longitudinal sectional view, as seen from below the

main assembly.

In (a) of Figure 34, the axis L2 is

substantially co-axial with the axis L1 as the

rotational force transmitting angular position of the

coupling member 150 in the state in which the drive of

the drum 20 is at rest.

In (b) of Figure 34, while the cartridge 2

moves to the front side (take-out direction X6) of the

main assembly 1, the drum 20 moves to the front side.

In response to this movement, the driving shaft

receiving surface 150f or the projection 150d of the

coupling member 150 contacts to the free end of the

shaft of the driving shaft 100 100c3 at least, so that

the axis L2 starts the inclination toward the upstream side of the take-out direction X6. This inclining direction is the same as the direction in which the coupling member 150 inclines at the time of the mounting of the cartridge 2.

In (c) of Figure 34, when the cartridge 2 is

further moved to the direction X6, the position of the

upstream free end with respect to the direction X6 150

A3 inclines until it reaches the free end 100c3 of the

shaft. The angle of the coupling member in this case

150 is the disengaging angular position which inclines

in the direction away from the axis Ll of the drum 20

from the rotational force transmitting angular

position.

In (d) of Figure 34, in this state, while

contacting to the free end 100c3 of the shaft, the

coupling member 150 advances. Although the angle

between the axis Li and the axis L2 differs from the

angle at the time of the mounting, the free end

position 150 A3 which is a part of coupling member 150

circumvents the free end 100c3 of the shaft similarly

to the case of the mounting.

In the state that the coupling member 150 is in

the disengaging angular position, it inclines relative

to the axis Li of the drum 20 so that the upstream

side thereof with respect to the removing direction of

dismounting the cartridge 2 from the main assembly 1

can pass by the free end of the driving shaft 100.

More particularly, when dismounting the cartridge 2

from the main assembly 1, the cartridge is moved in

the direction substantially perpendicular to the axis

of the drum 20 Li. In response to this movement, as

seen in the direction opposite from the removing

direction for dismounting the cartridge 2 from the

main assembly 1,, the coupling member 150 pivots to

the disengaging angular position from the rotational

force transmitting angular position so that a part of

the coupling member positioned behind the driving

shaft 100 is permitted to circumvent the driving shaft.

Thus, by the coupling member 150 pivoting, the

coupling member 150 disengages from the driving shaft

100.

Accordingly, in the case where the cartridge is

taken out, it is also expressed as a part of coupling

circumventing the driving shaft.

Thereafter, the cartridge 2 is taken out from

the main assembly 1.

Referring to Figure 35, the description will be

made in more detail about the tip shape of the driving

shaft 100. As an example of the simple configuration

of the driving shaft 100, there is a combination of

the semispherical surface 100f and the cylindrical

surface 100d shown in (a) of Figure 35. By the

semispherical surface 100f abutting to the funnel-like

driving shaft receiving surface (conic surface) 150f of the coupling member 150, the relative position between the driving shaft 100 and the coupling member

150 is determined. For this reason, it is desirable to

position the center (center of the sphere) of the

semispherical surface 100f on the centerline of the

drive transmission pin 100b. As shown in (b) of Figure

35, even if the coupling member 150 inclines during

the rotation, a distance Ra between the rotational

force receiving portion 150e and the drive

transmission pin 100b does not change. In addition, a

distance Rb between the driving shaft receiving

surface 150f and the drive transmission pin 100b does

not change, and therefore, the stabilized rotation can

be continued.

The present embodiment employs the

configuration in which the longitudinal size of the

driving shaft 100 is reducible. The radius of the

semispherical surface 100f which is the first

positioning portion is small in the configuration

shown in (b) of Figure 34. As shown in the description,

the center of the semispherical surface 100f is on the

centerline of the drive transmission pin 100b which is

rotational force applying portion. Correspondingly to

the reduction of the radius semi-spherical shape, the

drive transmission pin 100b approaches to the coupling

member 150.

The portion between the semispherical surface

100f and the cylindrical surface 100d is a conic

surface 100g as the guiding portion. As has been

described with Figure 32, by the time the coupling

member 150 engages completely with the driving shaft

100, it inclines from the pre-engagement angular

position to the rotational force transmitting angular

position. In this embodiment, in order to carry out

this operation smoothly, the conic surface 100g is

formed without a step.

1 The diameter of the cylindrical surface 100d

determines the amount of the play relative to the

coupling member 150. Immediately after the cartridge 2

is mounted to the main assembly 1, the funnel-like

driving shaft receiving surface (conic surface) 150f

of the coupling member 150 and the semispherical

surface of the driving shaft 100 100f may be separated

from each other by the gap, with respect to the

longitudinal direction, determined in consideration of

dimensional tolerance and so on. At this time, the

positioning function of the semispherical surface

(first positioning portion) 100f does not work. In

this embodiment, the play with respect to the radial

direction between the cylindrical surface (second

positioning portion) 100d and the coupling member 150

is small, so that the cylindrical surface 100d work(s)

as the second positioning portion to position the

coupling member 150 temporarily.

As has been described hereinbefore, the driving

shaft 100 has the semispherical surface 100f (first

positioning portion) and the cylindrical surface 100d

(second positioning portion) which are the positioning

portions relative to the coupling member 150. During

the rotational force transmission, the coupling member

150 contacts with the semispherical surface 100f, and

is spaced from the cylindrical surface 100d.

The semispherical surface 100f of the driving

shaft 100 has the substantial spherical shape. The

cylindrical surface 100d has the cylindrical shape.

In addition, the driving shaft 100 has the

conic surface (guiding portion) 100g which connects

between the semispherical surface 100f and the

cylindrical surface 100d.

(1) A process cartridge 2 is detachably

mountable to a main assembly 1 of an

electrophotographic image forming apparatus. The image

forming apparatus includes a driving shaft 100 having

a rotational force applying portion 100b by moving in

a direction substantially perpendicular to an axis of

the driving shaft 100. The process cartridge 2

comprises:

i) an electrophotographic photosensitive drum

20 rotatable about an axis Li and having a

photosensitive layer at its peripheral surface.

ii) process means 12, 41, 52 actable on the electrophotographic photosensitive drum 20.

iii) a coupling member 150 is engageable with

the rotational force applying portion 100b to receive

a rotational force for rotating the

electrophotographic photosensitive drum 20. The

coupling member 150 is capable of taking a rotational

force transmitting angular position for transmitting

the rotational force for rotating the

electrophotographic photosensitive drum 20 to the

electrophotographic photosensitive drum 20, a pre

engagement angular position in which the coupling

member 150 is inclined away from the axis Li of the

electrophotographic photosensitive drum 20 from the

rotational force transmitting angular position and a

disengaging angular position in which the coupling

member 150 is inclined away from the axis of the

electrophotographic photosensitive drum 20 from the

rotational force transmitting angular position.

iv) a regulating portion 170 for regulating an

inclination angle of the coupling member 150 such that

downward inclination angle of the coupling member 150

is smaller than an inclination angle of the coupling

member 150 when the coupling member 150 is at the pre

engagement angular position.

In mounting the process cartridge 2 to the main

assembly 1 of the apparatus by moving the process

cartridge 2 in a direction substantially perpendicular to the axis Li of the electrophotographic photosensitive drum 20, the coupling member 150 moves from the pre-engagement angular position to the rotational force transmitting angular position to oppose the driving shaft 100, and in dismounting the process cartridge 2 from the main assembly 1 of the apparatus by moving the process cartridge 2 in a direction substantially perpendicular to the axis of the electrophotographic photosensitive drum 20, the coupling member 150 moves from the rotational force transmitting angular position to the disengaging angular position to disengage from the driving shaft

100. The disengagement is enabled by movement of the

coupling member 150 to the disengagement angular

position.

With such structures, the cartridge 2 can be

mounted and dismounted relative to the main assembly 1

in a direction substantially perpendicular to the axis

L3.

(2) The regulating portion 170 surrounds the

coupling member 150 in a perpendicular direction

perpendicular to the axis Li of the

electrophotographic photosensitive drum 20 , and the

regulating portion 170 is provided with a first

arcuate portion 170a and a- projected portion 170b

projecting in the perpendicular direction continuing

from the first arcuate portion 170a , and wherein the first arcuate portion 170a regulates the downward inclination (by the gravity) of the coupling member

150 , and the projected portion 170b regulates the

inclination angle of the coupling member 150 in the

pre-engagement angular position.

(3) The first arcuate portion 170a is provided

with a regulating projection 170c projecting in the

axial direction from the first arcuate portion 170a.

The regulating projection 170c is provided with a

second arcuate portion 170d having the same radius of

arc as that of the first arcuate portion 170a, and a

flat surface portion 170e extending from the second

arcuate portion 170d toward the projected portion 170b.

When the coupling member 150 receives an external

force from the main assembly 1 of the apparatus, the

coupling member 150 is moved by the external force

along the second arcuate portion 170d and the flat

surface portion 170e to the projected portion 170b. By

this, the coupling member 150 is positioned at the

pre-engagement angular position.

With such structures, the inclination angle of

the coupling member 150 due to the gravity can be

regulated, and therefore, the cartridge 2 B can be

smoothly mounted to the main assembly 1.

(4) The main assembly 1 of the apparatus

includes a slider (urging member) 131, movable between

an urging position and a retracted position retracted from the urging position, for applying the external force. The coupling member 150 is urged by an elastic force of the slider 131 which when the process cartridge 2 is mounted to the main assembly 1 of the apparatus, contacts the process cartridge 2 to retracts temporarily from the urging position to the retracted position and then restore to the urging position so as to move along the second arcuate portion 170d and the flat surface portion 170e to the projected portion 170b. By this, the coupling member

150 is positioned at the pre-engagement angular

position.

With such a structure, the engagement between

the coupling member 150 and the driving shaft 100 is

assuredly established.

(5) The coupling member 150 has a recess

(driving shaft receiving surface) 150f in which a

rotational axis L2 of the coupling member 150 extends,

wherein when the process cartridge 2 is mounted to the

main assembly 1 of the electrophotographic image

forming apparatus, the process cartridge 2 pivots from

the pre-engagement angular position to the rotational

force transmitting angular position so that downstream

a part of the coupling member 150, with respect to the

mounting direction in which the process cartridge 2 is

mounted to the main assembly 1 of the

electrophotographic image forming apparatus circumvents the driving shaft 100. The recess 150f is over a free end of the driving shaft 100 in the state in which the coupling member 150 is positioned at the rotational force transmitting angular position. The coupling member 150 is rotated by a rotational force through engagement, in a rotational direction of the coupling member 150, to the rotational force applying portion 100b which is projected in a direction substantially perpendicular to an axis L3 of the driving shaft 100 adjacent to the free end of the driving shaft 100. When the process cartridge 2 is dismounted from the main assembly 1 of the electrophotographic image forming apparatus, the coupling member 150 is disengaged from the driving shaft 100 by moving (pivoting) from the rotational force transmitting angular position to the disengaging angular position so that part of the coupling member

150 circumvents the driving shaft 100 in response to

movement of the process cartridge 2 in the direction

substantially perpendicular to the axis Ll of the

electrophotographic photosensitive drum 20. By this,

the coupling member disengages from the driving shaft

100.

(6) A plurality of such rotational force

receiving portions 150e are provided on a phantom

circle C having a center on the rotational axis L2 of

the coupling member 150 at positions substantially diametrically opposite to each other.

(7) The recess includes an expanding portion

expanding toward a free end thereof. A plurality of

the rotational force receiving portions 150e are

provided at regular intervals along a rotational

direction of the coupling member 150. The rotational

force applying portion 100b is provided at each of two

positions which are diametrically opposite to each

other with respect to the axis L3 of the driving shaft

100. The coupling member 150 receives a rotational

force from the driving shaft 100 to rotate by one of

the rotational force receiving portions 150e engaging

to one of the rotational force applying portion 100b

and by the other of rotational force receiving

portions 150e engaging to the other of the rotational

force applying portions 100b. One of the rotational

force receiving portions 150e is opposed to the other

of the rotational force receiving portions 150e, and

one of the rotational force applying portions 100b is

opposed to the other of the rotational force applying

portions 100b.

With such structure, the coupling can rotate

smoothly.

(8) The expanding portion has a conical shape

having an apex "a" (center 0) on the rotational axis

of the coupling member 150. In the state in which

coupling member 150 is positioned at the rotational force transmitting angular position, the apex is opposed to the free end of the driving shaft 100, and the coupling member 150 is over the free end of the driving shaft 100 when the rotational force is transmitted to the coupling member 150. The rotational force receiving portions 150e are provided at regular intervals in a rotational direction of the coupling member 150.

(9) In the state in which coupling member 150

is positioned at the rotational force transmitting

angular position, the rotational axis L2 of the

coupling member 150 is substantially coaxial with the

axis Ll of the electrophotographic photosensitive drum

20, wherein in the state in which coupling member 150

is positioned at the pre-engagement angular position,

the coupling member 150 is inclined relative to the

axis Ll of the electrophotographic photosensitive drum

20 so that downstream a part thereof with respect to

the mounting direction in which the process cartridge

2 is mounted to the main assembly 1 of the apparatus

passes by the free end of the driving shaft, wherein

in the state in which coupling member 150 is

positioned at the disengaging angular position, the

rotational axis L2 of the coupling member 150 is

inclined relative to the axis Ll of the

electrophotographic photosensitive drum 20 so as to

permit an upstream portion of the coupling member 150 passes by the free end of the driving shaft 100 in a removing direction in which the process cartridge 2 is dismounted from the main assembly 1 of the electrophotographic image forming apparatus.

(10) The coupling member 150 is provided to an

end of the electrophotographic photosensitive drum 20

and is capable of revolvable relative to the axis Li

of the electrophotographic photosensitive drum 20

substantially in all directions.

With such structures, the coupling member 150

is capable of engaging and disengaging relative to the

driving shaft 100 irrespective of the phase of the

driving shaft 100.

(11) A gap is provided between the rotating

force transmitting portion 155 and the rotating force

receiving member 151h so that coupling member 150 is

capable of tilting relative to the axis Li of the

electrophotographic photosensitive drum 20

substantially in all directions. The rotating force

transmitting portion 155 is provided at an end of the

electrophotographic photosensitive drum 20 and is

movable relative to the rotating force receiving

member 151h. The rotating force transmitting portion

155 and the rotating force receiving member 151h are

engageable to each other in a rotational direction of

the coupling member 150.

(12) The coupling member 150 is provided with a rotating force transmitting portion 155 for transmitting the rotating force to be transmitted to the electrophotographic photosensitive drum 20, the rotating force transmitting portion 155 being arranged in line with the rotating force receiving portion in the rotational axis L2 direction of the coupling member 150 , the coupling member 150 is further provided with an intermediary portion 150c between the rotating force receiving portion and the rotating force transmitting portion 155 , and wherein when the process cartridge 2 is moved in the direction substantially perpendicular to the driving shaft 100 the intermediary portion 150c is contacted by a fixed portion (main assembly guide 130R1) of the main assembly 1 of the apparatus so that coupling member

150 takes the pre-engagement angular position.

With such structures, the coupling member 150

can assuredly engage with the coupling member 150.

The structures of the electrophotographic image

forming apparatus according to the above-described

embodiments are summarized as follows.

(13) The electrophotographic image forming

apparatus includes a main assembly to which a process

cartridge 2 is detachably mountable. The

electrophotographic image forming apparatus comprises:

i) a driving shaft 100 having a rotating force

applying portion 100b.

ii) a process cartridge 2 including.

an electrophotographic photosensitive drum 20

rotatable about an axis Li and having a photosensitive

layer at its peripheral surface,

process means (12, 41, 52) actable on the

electrophotographic photosensitive drum 20,

a coupling member 150 engageable with the

rotational force applying portion 100b to receive a

rotational force for rotating the electrophotographic

photosensitive drum 20, wherein the coupling member

150 is capable of taking a rotational force

transmitting angular position for transmitting the

rotational force for rotating the electrophotographic

photosensitive drum 20 to the electrophotographic

photosensitive drum 20, a pre-engagement angular

position in which the coupling member 150 is inclined

away from the axis L1 of the electrophotographic

photosensitive drum 20 from the rotational force

transmitting angular position and a disengaging

angular position in which the coupling member 150 is

inclined away from the axis LI of the

electrophotographic photosensitive drum 20 from the

rotational force transmitting angular position,

a regulating portion 170 for regulating an

inclination angle of the coupling member 150 such that

downward inclination angle of the coupling member 150

is smaller than an inclination angle of the coupling member 150 when the coupling member 150 is at the pre engagement angular position, wherein in mounting the process cartridge 2 to the main assembly 1 of the apparatus by moving the process cartridge 2 in a direction substantially perpendicular to the axis Li of the electrophotographic photosensitive drum 20, the coupling member 150 moves from the pre-engagement angular position to the rotational force transmitting angular position to oppose the driving shaft 100, and in dismounting the process cartridge 2 from the main assembly 1 of the apparatus by moving the process cartridge 2 in a direction substantially perpendicular to the axis of the electrophotographic photosensitive drum 20, the coupling member 150 moves from the rotational force transmitting angular position to the disengaging angular position to disengage from the driving shaft 100.

(14) The regulating portion 170 surrounds the

coupling member 150 in a perpendicular direction

perpendicular to the axis Li of the

electrophotographic photosensitive drum 20 , and the

regulating portion 170 is provided with a first

arcuate portion 170a and a projected portion 170b

projecting in the perpendicular direction continuing

from the first arcuate portion 170a , and wherein the

first arcuate portion 170a regulates the downward inclination (by the gravity) of the coupling member

150 , and the projected portion 170b regulates the

inclination angle of the coupling member 150 in the

pre-engagement angular position.

(15) The first arcuate portion 170a is

provided with a regulating projection 170c projecting

in the axial direction from the first arcuate portion

170a. The regulating projection 170c is provided with

a second arcuate portion 170d having the same radius

of arc as that of the first arcuate portion 170a, and

a flat surface portion 170e extending from the second

arcuate portion 170d toward the projected portion 170b.

When the coupling member 150 receives an external

force from the main assembly 1 of the apparatus, the

coupling member 150 is moved by the external force

along the second arcuate portion 170d and the flat

surface portion 170e to the projected portion 170b. By

this, the coupling member 150 is positioned at the

pre-engagement angular position.

With such structures, the inclination angle of

the coupling member 150 due to the gravity can be

regulated, and therefore, the cartridge 2 B can be

smoothly mounted to the main assembly 1.

(16) The main assembly 1 of the apparatus

includes a slider (urging member) 131, movable between

an urging position and a retracted position retracted

from the urging position, for applying the external force. The coupling member 150 is urged by an elastic force of the slider 131 which when the process cartridge 2 is mounted to the main assembly 1 of the apparatus, contacts the process cartridge 2 to retracts temporarily from the urging position to the retracted position and then restore to the urging position so as to move along the second arcuate portion 170d and the flat surface portion 170e to the projected portion 170b. By this, the coupling member

150 is positioned at the pre-engagement angular

position.

(17) The coupling member 150 has a recess

(driving shaft receiving surface) 150f in which a

rotational axis L2 of the coupling member 150 extends,

wherein when the process cartridge 2 is mounted to the

main assembly 1 of the electrophotographic image

forming apparatus, the process cartridge 2 pivots from

the pre-engagement angular position to the rotational

force transmitting angular position so that downstream

a part of the coupling member 150, with respect to the

mounting direction in which the process cartridge 2 is

mounted to the main assembly 1 of the

electrophotographic image forming apparatus

circumvents the driving shaft 100. The recess 150f is

over a free end of the driving shaft 100 in the state

in which the coupling member 150 is positioned at the

rotational force transmitting angular position. The coupling member 150 is rotated by a rotational force through engagement, in a rotational direction of the coupling member 150, to the rotational force applying portion 100b which is projected in a direction substantially perpendicular to an axis L3 of the driving shaft 100 adjacent to the free end of the driving shaft 100. When the process cartridge 2 is dismounted from the main assembly 1 of the electrophotographic image forming apparatus, the coupling member 150 is disengaged from the driving shaft 100 by moving (pivoting) from the rotational force transmitting angular position to the disengaging angular position so that part of the coupling member

150 circumvents the driving shaft 100 in response to

movement of the process cartridge 2 in the direction

substantially perpendicular to the axis Li of the

electrophotographic photosensitive drum 20. By this,

the coupling member disengages from the driving shaft

100.

(18) In the state in which coupling member 150

is positioned at the rotational force transmitting

angular position, the rotational axis L2 of the

coupling member 150 is substantially coaxial with the

axis L1 of the electrophotographic photosensitive drum

20, wherein in the state in which coupling member 150

is positioned at the pre-engagement angular position,

the coupling member 150 is inclined relative to the axis Li of the electrophotographic photosensitive drum

20 so that downstream a part thereof with respect to

the mounting direction in which the process cartridge

2 is mounted to the main assembly 1 of the apparatus

passes by the free end of the driving shaft, wherein

in the state in which coupling member 150 is

positioned at the disengaging angular position, the

rotational axis L2 of the coupling member 150 is

inclined relative to the axis Li of the

electrophotographic photosensitive drum 20 so as to

permit an upstream portion of the coupling member 150

passes by the free end of the driving shaft 100 in a

removing direction in which the process cartridge 2 is

dismounted from the main assembly 1 of the

electrophotographic image forming apparatus.

(19) The coupling member 150 is provided with

a rotating force transmitting portion 155 for

transmitting the rotating force to be transmitted to

the electrophotographic photosensitive drum 20, the

rotating force transmitting portion 155 being arranged

in line with the rotating force receiving portion in

the rotational axis L2 direction of the coupling

member 150 , the coupling member 150 is further

provided with an intermediary portion 150c between the

rotating force receiving portion and the rotating

force transmitting portion 155 , and wherein when the

process cartridge 2 is moved in the direction substantially perpendicular to the driving shaft 100 the intermediary portion 150c is contacted by a fixed portion (main assembly guide 130R1) of the main assembly 1 of the apparatus so that coupling member

150 takes the pre-engagement angular position.

As shown in (d) of Figure 34, in the rotational

force transmitting angular position of the coupling

member 150, the angle relative to the axis Li of the

coupling member 150 is such that in the state where

the cartridge (B) is mounted to the apparatus main

assembly (A), the coupling member 150 receives the

transmission of the rotational force from the driving

shaft 180, and it rotates. In the rotational force

transmitting angular position of the coupling member

150, the rotational force for rotating the

photosensitive drum is transmitted to the drum.

As shown in (d) of Figure 34, in the pre

engagement angular position of the coupling member 150,

the angular position relative to the axis Li of the

coupling member 150 is such that it is in the state

immediately before the coupling member 150 engages

with the driving shaft 100 in the mounting operation

to the apparatus main assembly 1 of the cartridge 2.

More particularly, it is the angular position relative

to the axis L1 which the downstream free end portion

150Al of the coupling 150 can pass by the driving

shaft 100 with respect to the mounting direction of the cartridge 2.

As shown in (d) of Figure 34, the disengaging

angular position of the coupling member 150 is the

angular position relative to the axis Li of the

coupling member 150 at the time of taking out the

cartridge 2 from the apparatus main assembly 1, in the

case that the coupling 150 disengages from the driving

shaft 180. More particularly, as shown in (d) of

Figure 34, it is the angular position relative to the

axis Li with which the free end portion 150 A3 of the

coupling 150 can pass by the driving shaft 180 with

respect to the removing direction (X6) of the

cartridge (B).

In the pre-engagement angular position or the

disengaging angular position, the angle theta 2 which

the axis L2 makes with the axis L1 is larger than the

angle theta 1 which the axis L2 makes with the axis Ll

in the rotational force transmitting angular position.

As for the angle theta 1, 0 degree is preferable.

However, in this embodiment, if the angle theta 1 is

less than about 15 degrees, the smooth transmission of

the rotational force is accomplished. This is also one

of the effects of this embodiment. As for the angle

theta 2, the range of about 20 - 60 degrees is

preferable.

(20) The driving shaft 100 is provided with a

first positioning portion 100f and a second positioning portion 100d relative to the coupling member 150. During rotating force transmission , the coupling member 150 contacts the first positioning portion , and is spaced from the second positioning portion.

The structures of the electrophotographic

photosensitive drum according to -the above-described

embodiments are summarized as follows.

(21) The electrophotographic photosensitive

drum unit 21 is detachably mountable to a main

assembly 1 of an electrophotographic image forming

apparatus. The main assembly includes a driving shaft

100 having a rotational force applying portion 100b by

moving in a direction substantially perpendicular to

an axis of the driving shaft 100, the drum unit 21

comprises:

i) an electrophotographic photosensitive drum

20 rotatable about an axis LI and having a

photosensitive layer at its peripheral surface.

ii) a coupling member 150 is engageable with

the rotational force applying portion 100b to receive

a rotational force for rotating the

electrophotographic photosensitive drum 20. The

coupling member 150 is capable of taking a rotational

force transmitting angular position for transmitting

the rotational force for rotating the

electrophotographic photosensitive drum 20 to the electrophotographic photosensitive drum 20, a pre engagement angular position in which the coupling member 150 is inclined away from the axis Li of the electrophotographic photosensitive drum 20 from the rotational force transmitting angular position and a disengaging angular position in which the coupling member 150 is inclined away from the axis of the electrophotographic photosensitive drum 20 from the rotational force transmitting angular position.

iii) a regulating portion 170 for regulating an

inclination angle of the coupling member 150 such that

downward inclination angle of the coupling member 150

is smaller than an inclination angle of the coupling

member 150 when the coupling member 150 is at the pre

engagement angular position.

In mounting the process cartridge 2 to the main

assembly 1 of the apparatus by moving the process

cartridge 2 in a direction substantially perpendicular

to the axis Ll of the electrophotographic

photosensitive drum 20, the coupling member 150 moves

from the pre-engagement angular position to the

rotational force transmitting angular position to

oppose the driving shaft 100, and in dismounting the

process cartridge 2 from the main assembly 1 of the

apparatus by moving the process cartridge 2 in a

direction substantially perpendicular to the axis of

the electrophotographic photosensitive drum 20, the coupling member 150 moves from the rotational force transmitting angular position to the disengaging angular position to disengage from the driving shaft

100. The disengagement is enabled by movement of the

coupling member 150 to the disengagement angular

position.

(22) The regulating portion 170 surrounds the

coupling member 150 in a perpendicular direction

perpendicular to the axis Ll of the

electrophotographic photosensitive drum 20 , and the

regulating portion 170 is provided with a first

arcuate portion 170a and a projected portion 170b

projecting in the perpendicular direction continuing

from the first arcuate portion 170a , and wherein the

first arcuate portion 170a regulates the downward

inclination (by the gravity) of the coupling member

150 , and the projected portion 170b regulates the

inclination angle of the coupling member 150 in the

pre-engagement angular position.

(23) The first arcuate portion 170a is

provided with a regulating projection 170c projecting

in the axial direction from the first arcuate portion

170a. The regulating projection 170c is provided with

a second arcuate portion 170d having the same radius

of arc as that of the first arcuate portion 170a, and

a flat surface portion 170e extending from the second

arcuate portion 170d toward the projected portion 170b.

When the coupling member 150 receives an external

force from the main assembly 1 of the apparatus, the

coupling member 150 is moved by the external force

along the second arcuate portion 170d and the flat

surface portion 170e to the projected portion 170b. By

this, the coupling member 150 is positioned at the

pre-engagement angular position.

With such structures, the inclination angle of

the coupling member 150 due to the gravity can be

regulated, and therefore, the cartridge 2 can be

smoothly mounted to the main assembly 1.

(24) The main assembly 1 of the apparatus

includes a slider (urging member) 131, movable between

an urging position and a retracted position retracted

from the urging position, for applying the external

force. The coupling member 150 is urged by an elastic

force of the slider 131 which when the process

cartridge 2 is mounted to the main assembly 1 of the

apparatus, contacts the process cartridge 2 to

retracts temporarily from the urging position to the

retracted position and then restore to the urging

position so as to move along the second arcuate

portion 170d and the flat surface portion 170e to the

projected portion 170b. By this, the coupling member

150 is positioned at the pre-engagement angular

position.

(25) A plurality of such rotational force receiving portions 150e are provided on a phantom circle C having a center on the rotational axis L2 of the coupling member 150 at positions substantially diametrically opposite to each other.

(26) The coupling member 150 is provided with

a recess including an expanding portion expanding

toward a free end thereof. A plurality of the

rotational force receiving portions 150e are provided

at regular intervals along a rotational direction of

the coupling member 150. The rotational force applying

portion 100b is provided at each of two positions

which are diametrically opposite to each other with

respect to the axis L3 of the driving shaft 100. The

coupling member 150 receives a rotational force from

the driving shaft 100 to rotate by one of the

rotational force receiving portions 150e engaging to

one of the rotational force applying portion 100b and

by the other of rotational force receiving portions

150e engaging to the other of the rotational force

applying portions 100b. One of the rotational force

receiving portions 150e is opposed to the other of the

rotational force receiving portions 150e, and one of

the rotational force applying portions 100b is opposed

to the other of the rotational force applying portions

100b.

With such structure, the coupling can rotate

smoothly and stably.

The expanding portion has a conical shape

having an apex "a" (center 0) on the rotational axis

of the coupling member 150. In the state in which

coupling member 150 is positioned at the rotational

force transmitting angular position, the apex is

opposed to the free end of the driving shaft 100, and

the coupling member 150 is over the free end of the

driving shaft 100 when the rotational force is

transmitted to the coupling member 150. The rotational

force receiving portions 150e are provided at regular

intervals in a rotational direction of the coupling

member 150.

With such a structure, the coupling member 150

can receive a smooth and stabilized rotating force.

According to the embodiments of the present

invention, a process cartridge which is detachably

mountable to a main assembly of an image forming

apparatus having a driving shaft, in a direction

substantially perpendicular to the axis of the driving

shaft. Also, there are provided an electrophotographic

photosensitive drum unit usable with such a process

cartridge, and an electrophotographic image forming

apparatus to which such a process cartridge is

detachably mountable.

According to the embodiments of the present

invention, the rotation accuracy of the

electrophotographic photosensitive drum can be improved as compared with the case that engaging gears are used to transmit the rotational force from the main assembly to the process cartridge.

According to the embodiments of the present

invention, before the process cartridge is mounted to

the main assembly, the coupling member is prevented

from inclining in an unnecessary direction to a great

extend, and therefore, the process cartridge can be

smoothly mounted to the main assembly. In addition,

there are provided an electrophotographic

photosensitive drum unit usable with such a process

cartridge, and an electrophotographic image forming

apparatus to which such a process cartridge is

detachably mountable.

[INDUSTRIAL APPLICABILITY]

According to the present invention, it is

possible to provide a process cartridge which is

mountable to the-main assembly which is not provided

with the mechanism for moving the main assembly side

coupling member for transmitting the rotational force

to the drum, by the opening and closing operation of

the main assembly cover in the axial direction. The

process cartridge is capable of rotating the drum

smoothly.

The present invention can also provide an

electrophotographic photosensitive drum unit usable with the process cartridge and the electrophotographic image forming apparatus relative to which the process cartridge is mountable and dismountable.

While the invention has been described with

reference to the structures disclosed herein, it is

not confined to the detailsset forth, and this

application is intended to cover such modification or

changes as may come within the purposes of the

improvements or the scope of the following claims.

Claims (7)

CLAIMS:

1. A process cartridge which is detachably mountable to a main assembly of an electrophotographic image forming apparatus including a driving shaft having a rotational force applying portion, by moving in a mounting direction substantially perpendicular to an axis of said driving shaft, said process cartridge comprising: i) a bearing member; ii) a photosensitive drum supported by said bearing member rotatably about a drum axis thereof; iii) a coupling member provided at an axial end portion of said photosensitive drum and rotatable about a coupling axis thereof so as to transmit a driving force from the driving shaft to said photosensitive drum, said coupling member being capable of moving relative to said photosensitive drum between a first position in which said coupling axis is coaxial with said drum axis and a second position in which said coupling axis is not coaxial with said drum axis; and

iv) a hole portion provided on said bearing member and penetrated by said coupling member, said hole portion being configured to regulate the motion of said coupling member, wherein said hole portion is provided with a recess that is recessed along the mounting direction away from said drum axis, wherein said coupling member moves from the first position to the second position by a movement away from said drum axis toward said recess, and

wherein a movable range of the coupling member away from said drum axis along the mounting direction toward the recess is larger than a movable range of the coupling member away from said drum axis along another direction.

2. A process cartridge according to Claim 1, wherein said coupling member includes a first end portion movably connected with said photosensitive drum, a second end portion capable of receiving the rotational force from the rotational force applying portion, and a connecting portion connecting said first end portion and said second end portion with each other, and

wherein at least a part of said connecting portion is capable of entering said recess.

3. A process cartridge according to Claim 2, wherein said connecting portion is in the form of a shaft extending along the coupling axis.

4. A process cartridge according to Claim 2, wherein said hole portion includes a guide portion that guides said coupling member into said recess when said coupling member receives an external force toward said guide portion at a side opposite said guide portion.

5. A process cartridge according to Claim 4, wherein said guide portion extends outwardly along a direction of the drum axis of said photosensitive drum.

6. A process cartridge according to Claim 4, wherein said guide portion guides said coupling member into said recess by contacting said second end portion of said coupling member.

7. A process cartridge according to Claim 1, further comprising a rotatable developing roller configured to develop a latent image formed on said photosensitive drum, wherein said recess is recessed away from said developing roller.

Canon Kabushiki Kaisha Patent Attorneys for the Applicant SPRUSON&FERGUSON wo 2009/154312 PCT/JP2009/061673 1/ 27 May 2021 l.. I 2021202841

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100

130R l o

Fig. 24 wo 2009/15-'312 PCT/JP2009/061673 17/ 27 May 2021

140R i o

l40R2 2021202841

I SOc

l31b

Fig. 25 wo 2009/154312 PCT/JP2009/061673 18/ 27 May 2021

150c 2021202841

150d

ISO 140R l - - 150e 20 130 Ric

--~-- 130R 1b 158h

Fig. 26

WO 2009/1S.t312 PCT/JP2009/061673 19/ 27 May 2021

140Rlo 2021202841

130Ric

Fig. 27 wo 2009/154312 PCT/JP2009/061673 20/ 27 May 2021

130R i c 2021202841

140RI

l30R i o

Fig. 28 wo 2009/1543 12 PCTI JP2009/061673 21 / 27 May 2021 l50c ( a) l40R I o 2021202841

132 13 1

(b)

150c 160

170e

150a

\ f 0 g. Fig. 29 wo 2009/154312 PCT/JP2009/061673 22/ 27 May 2021

X4

~ 2021202841

l30R i b

130R 1o

131

Fig. 30 wo 2009! 15-1312

23127 PCT!JP2009!061673 May 2021

23/27

(a) 2021202841

X4 ~ 170

(b)

Fig. 31 Fig. 31 wo 2009/154312 PCT/JP2009/061673 24/27 May 2021

(a) ~ X4 150

157 / l2 -......._., 2021202841

L wo 2009/154312 PCT/JP2009/061673 25/ 27 May 2021

18 I 2021202841

L1

I 51 lOOb

Fig. 33 wo 2009/154312 PCT/JP2009/061673 26/ 27 May 2021

(a) 151

15 0A3 151m 150 2021202841

(b) 151

IOOb

I l2 L1--· ._ / 100

X6 L3

150f I 00c3· 151m l50d (c) 151 L2 150 100

I X6 L3 100c3

( d) 151

) LI X6 100b

Fig. 34 150A3 wo 2009/15.t312 PCT/JP2009/061673 27/ 27 May 2021

L4

100 2021202841

(a)

(b)

/ 150

LS

(c)

Fig. 35