TECHNICAL FIELD

The present invention relates to a process cartridge and an electrophotographic image forming apparatus using the same.

Here, the process cartridge is a cartridge which is integrally formed with a photosensitive member and a process means actable on the photosensitive member so as to be dismountably mounted to a main assembly of the electrophotographic image forming apparatus.

For example, a photosensitive member and at least one of a developing means, a charging means and a cleaning means as the process means are integrally formed into a cartridge. Also, the electrophotographic image forming apparatus forms an image on a recording material using an electrophotographic image forming process.

Examples of the electrophotographic image forming apparatus include an electrophotographic copying machine, an electrophotographic printer (LED printer, laser beam printer, etc.), a facsimile machine, a word processor, and the like.

BACKGROUND ART

In an electrophotographic image forming apparatus (hereinafter also simply referred to as “image forming apparatus”), a drum type electrophotographic photosensitive member as an image bearing member, that is, a photosensitive drum (electrophotographic photosensitive drum) is uniformly charged. Subsequently, the charged photosensitive drum is selectively exposed to form an electrostatic latent image (electrostatic image) on the photosensitive drum. Next, the electrostatic latent image formed on the photosensitive drum is developed as a toner image with toner as developer. Then, the toner image formed on the photosensitive drum is transferred onto a recording material such as recording sheet, plastic sheet, and so on, and heat and pressure are applied to the toner image transferred onto the recording material to fix the toner image on the recording material, so that image recording is carried out.

Such an image forming apparatus generally requires toner replenishment and maintenance of various process means. In order to facilitate toner replenishment and maintenance, process cartridges dismountably mountable to the image forming apparatus main assembly have been put into cartridges by integrating photosensitive drums, charging means, developing means, cleaning means and the like in the frame.

With this process cartridge system, a part of the maintenance operation of the apparatus can be carried out by the user him/herself without relying on a service person in charge of after-sales service. Therefore, it is possible to improve the usability of the apparatus remarkably, and it is possible to provide an image forming apparatus excellent in usability. For this reason, this process cartridge system is widely used with image forming apparatus.

As described in JP H08-328449 (page 20, FIG. 16), a well-known image forming apparatus of the type described above includes a drive transmission member having a coupling at the free end thereof for transmitting drive to the process cartridge from the main assembly of the image forming apparatus, which is spring biased toward the process cartridge.

When an opening and closing door of the image forming apparatus main assembly is closed, the drive transmission member of this image forming apparatus is pressed by the spring and moves toward the process cartridge. By doing so, the drive transmission member engages (couples) with the coupling of the process cartridge and the drive transmission to the process cartridge is enabled. Also, when the opening/closing door of the image forming apparatus main assembly is opened, the drive transmission member moves in a direction away from the process cartridge against the spring by a cam. By this, the drive transmitting member disestablishes the engagement (coupling) with the coupling of the process cartridge, so that the process cartridge can be dismounted from the main assembly of the image forming apparatus.

SUMMARY OF THE INVENTION

Problems to be Solved by the Invention

The object of the present invention is to further develop the aforementioned prior art.

Means for Solving the Problem

Typical structure of the invention of this application is,

A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, said process cartridge comprising a photosensitive member; a coupling portion provided at an end portion of said photosensitive member and including a driving force receiving portion for receiving a driving force for rotating said photosensitive member, from an outside of said process cartridge; and a gear portion including gear teeth for receiving a driving force from an outside of said process cartridge, independently from said coupling portion, wherein said gear teeth include an exposed portion exposed to an outside of said process cartridge, wherein at least a part of said exposed portion (a) faces an axis of said photosensitive member, (b) is disposed outside of said driving force receiving portion in an axial direction of said photosensitive member, and (c) is in a neighborhood of a peripheral surface of said photosensitive member.

Another structure is,

A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, said main assembly including a drive output member having an output gear portion and an output coupling portion which are coaxial with each other, said process cartridge comprising a photosensitive member; an input coupling portion provided at an end portion of said photosensitive member and capable of coupling with the output coupling portion; and an input gear portion capable of meshing engagement with said output gear portion; wherein said input gear portion is configured such that said input gear portion and said output gear portion attract toward each other by rotations thereof in the state that said input gear portion and said output gear portion are in meshing engagement with each other.

A further structure is,

A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, said process cartridge comprising a photosensitive member; a coupling portion provided at an end portion of said photosensitive member and including a driving force receiving portion for receiving a driving force for rotating said photosensitive member, from an outside of said process cartridge; and a gear portion including a gear tooth for receiving, independently of said coupling portion, a driving force from a outside of said process cartridge; wherein said gear tooth is a helical gear tooth, and includes an exposed portion exposed to an outside of said process cartridge, wherein at least a part of said exposed portion is disposed outside of said driving force receiving portion in an axial direction of said photosensitive member and is faced to an axis of said photosensitive member.

A further structure is,

A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, said process cartridge comprising a photosensitive member; a coupling portion provided at an end portion of said photosensitive member and including a driving force receiving portion configured to receive a driving force for rotating said photosensitive member from an outside of said process cartridge; a gear portion including a gear tooth for receiving, independently of said coupling portion, a driving force from a outside of said process cartridge; and a developer carrying member configured to carry the developer to develop a latent image formed on said photosensitive member, said developer carrying member being rotatable in a clockwise direction as seen in such a direction that said gear portion rotates in the clockwise direction; wherein said gear teeth include an exposed portion exposed to an outside of said process cartridge, wherein at least a part of said exposed portion is faced to a axis of said photosensitive member and is disposed outside of said driving force receiving portion in an axial direction of said photosensitive member.

A further structure is,

A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, said process cartridge comprising a photosensitive member; an alignment portion provided coaxially with said photosensitive member; and gear portion including a gear tooth for receiving a driving force from an outside of said process cartridge; wherein said gear teeth include an exposed portion exposed to an outside of said process cartridge, wherein at lease a part of said stopper is (a) faced to an axis of said photosensitive member, (b) is disposed outside beyond said alignment portion in the axial direction of said photosensitive member and (c) is disposed adjacent to a peripheral surface of said photosensitive member in a plane perpendicular to the axis of said photosensitive member.

A further structure is,

A process cartridge detachably mountable to a main assembly of an electrophotographic image forming operation, the main assembly including a drive output member having an output gear portion and a main assembly side alignment portion which are coaxial with each other, said process cartridge comprising a photosensitive member; a cartridge side alignment portion engageable with the main assembly side alignment portion to effect alignment between said photosensitive member and the drive output member; and an input gear portion capable of meshing engagement with said output gear portion; wherein said input gear portion is configured such that said input gear portion and said output gear portion attract toward each other by rotations thereof in the state that said input gear portion and said output gear portion are in meshing engagement with each other.

A further structure is,

A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, said process cartridge comprising a photosensitive member; an alignment portion provided coaxially with said photosensitive member; and a gear portion including a gear tooth for receiving a driving force from an outside of said process cartridge, wherein said gear tooth is a helical gear tooth, and includes an exposed portion exposed to an outside of said process cartridge, wherein at least a part of said exposed portion is disposed outside of said alignment portion in an axial direction of said photosensitive member and is faced to the axis of said photosensitive member.

A further structure is,

A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, said process cartridge comprising a photosensitive member; an alignment portion provided coaxially with said photosensitive member; a gear portion including a gear tooth configured to receive a driving force from an outside of said process cartridge; and a developer carrying member configured to carry the developer to develop a latent image formed on said photosensitive member, said developer carrying member being rotatable in a clockwise direction as seen in such a direction that said gear portion rotates in the clockwise direction, wherein said gear teeth include an exposed portion exposed to an outside of said process cartridge, and wherein at least a part of said exposed portion is faced to the axis of said photosensitive member and is disposed outside of said alignment portion in the axial direction of said photosensitive member.

Effect of the Invention

It is possible to further develop the aforementioned prior art.

