Electrophotographic image forming apparatus to which a process cartridge is detachably mountable and process cartridge comprising cartridge drum positioning portion or recess

A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, comprising:

• a cartridge frame;
• an electrophotographic photosensitive drum supported on said cartridge frame;
• wherein said electrophotographic photosensitive drum has a leading end portion, with respect to a mounting direction in which said process cartridge is mounted to the main assembly of the electrophotographic image forming apparatus in the axial direction of said electrophotographic photosensitive drum, and is supported on said cartridge frame for movement in a direction crossing with the axial direction of said electrophotographic photosensitive drum;
• a developing roller for developing an electrostatic latent image formed on said electrophotographic photosensitive drum;
• a charging roller for charging said electrophotographic photosensitive drum;
• a cartridge drum positioning recess for positioning said electrophotographic photosensitive drum to the main assembly of the electrophotographic image forming apparatus by engagement with a main assembly drum positioning portion provided in the main assembly of the electrophotographic image forming apparatus when said process cartridge is mounted to the main assembly of the electrophotographic image forming apparatus;
• wherein said cartridge drum positioning recess is disposed coaxially with said electrophotographic photosensitive drum, and said cartridge drum positioning recess is provided at a center of a circular projected portion of a flange of said electrophotographic photosensitive drum, and wherein said flange is mounted at one end portion of a cylinder of said electrophotographic photosensitive drum in the axial direction of said electrophotographic photosensitive drum,
• a positioning cylindrical portion for positioning said cartridge frame to the main assembly of the apparatus by engagement with a main assembly frame positioning portion provided in the main assembly of the electrophotographic image forming apparatus when said process cartridge is mounted to the main assembly of the apparatus;
• wherein said positioning cylindrical portion is disposed at a leading end of said process cartridge, with respect to the mounting direction in which said process cartridge is mounted to the main assembly of the apparatus, and said positioning cylindrical portion is disposed such that it is coaxial with said electrophotographic photosensitive drum when said electrophotographic photosensitive drum is positioned to the main assembly of the apparatus by engagement of said cartridge drum positioning recess with the main assembly drum positioning portion, wherein said positioning cylindrical portion is extended in the mounting direction on said cartridge frame, wherein said positioning cylindrical portion is outwardly projected from a free end surface of said cartridge frame, and wherein said positioning cylindrical portion is extended from outside to inside of said cartridge frame;
• and
• a cartridge coupling for reception of a driving force for rotating said electrophotographic photosensitive drum through a main assembly coupling provided in the main assembly of the electrophotographic image forming apparatus when said process cartridge is mounted to the main assembly of the electrophotographic image forming apparatus, and said cartridge drum positioning recess is disposed at a center of said cartridge coupling and said circular projected portion.

An electrophotographic image forming apparatus for forming an image on a recording material, to which a process cartridge is detachably mountable, comprising:

• (a) a main assembly drum positioning portion;
• (b) a main assembly frame positioning portion;
• (c) a mounting member for detachably mounting a process cartridge, the process cartridge including:
• a cartridge frame;
• an electrophotographic photosensitive drum supported on the cartridge frame;
• wherein the electrophotographic photosensitive drum has a leading end portion, with respect to a mounting direction in which the process cartridge is mounted to a main assembly of said electrophotographic image forming apparatus in the axial direction of the electrophotographic photosensitive drum, and is supported on the cartridge frame for movement in a direction crossing with the axial direction of the electrophotographic photosensitive drum;
• process means actable on the electrophotographic photosensitive drum;
• a cartridge drum positioning portion for positioning the electrophotographic photosensitive drum to the main assembly of said electrophotographic image forming apparatus by engagement with said main assembly drum positioning portion when the process cartridge is mounted to the main assembly of said electrophotographic image forming apparatus, wherein the cartridge drum positioning portion is disposed coaxial with the electrophotographic photosensitive drum;
• and
• a cartridge frame positioning portion for positioning the cartridge frame to the main assembly of said electrophotographic image forming apparatus by engagement with said main assembly frame positioning portion when the process cartridge is mounted to the main assembly of said electrophotographic image forming apparatus, wherein the cartridge frame positioning portion is disposed at a leading end portion of the process cartridge with respect to the mounting direction in which the process cartridge is mounted to the main assembly of said electrophotographic image forming apparatus.

An electrophotographic image forming apparatus for forming an image on a recording material, to which a process cartridge is detachably mountable, comprising:

• (a) a main assembly drum positioning portion;
• (b) a main assembly frame positioning portion;
• (c) a main assembly coupling;
• (d) a mounting member for detachably mounting a process cartridge, the process cartridge including:
• a cartridge frame;
• an electrophotographic photosensitive drum supported on the cartridge frame;
• wherein the electrophotographic photosensitive drum has a leading end portion, with respect to a mounting direction in which the process cartridge is mounted to a main assembly of the electrophotographic image forming apparatus in the axial direction of the electrophotographic photosensitive drum, and is supported on the cartridge frame for movement in a direction crossing with the axial direction of the electrophotographic photosensitive drum;
• a developing roller for developing an electrostatic latent image formed on the electrophotographic photosensitive drum;
• a charging roller for charging the electrophotographic photosensitive drum;
• a cartridge drum positioning recess for positioning the electrophotographic photosensitive drum to the main assembly said electrophotographic image forming apparatus by engagement with the main assembly drum positioning portion when the process cartridge is mounted to the main assembly of said electrophotographic image forming apparatus, wherein the cartridge drum positioning recess is disposed coaxially with the electrophotographic photosensitive drum, and the cartridge drum positioning recess is provided at the center of a circular projected portion of a flange of the electrophotographic photosensitive drum, and wherein the flange is mounted at one end portion of a cylinder of the electrophotographic photosensitive drum in an axial direction of the electrophotographic photosensitive drum;
• a positioning cylindrical portion for positioning the cartridge frame to the main assembly of said electrophotographic image forming apparatus by engagement with said main assembly frame positioning portion when the process cartridge is mounted to the main assembly of said electrophotographic image forming apparatus;
• wherein the positioning cylindrical portion is disposed at a leading end, with respect to the mounting direction in which the process cartridge is mounted to the main assembly of said electrophotographic image forming apparatus, and the positioning cylindrical portion is disposed such that it is coaxial with the electrophotographic photosensitive drum when the electrophotographic photosensitive drum is positioned to the main assembly of said electrophotographic image forming apparatus by engagement of the cartridge drum positioning recess with said main assembly drum positioning portion,
• wherein the positioning cylindrical portion is extended along the mounting direction on the cartridge frame, and the positioning cylindrical portion is projected outwardly from a free end surface of the cartridge frame, and the positioning cylindrical portion is extended from outside to inside of the cartridge frame;
• and
• a cartridge coupling for receiving a driving force for rotating the electrophotographic photosensitive drum through a main assembly coupling provided in the main assembly of said electrophotographic image forming apparatus when the process cartridge is mounted to the main assembly of said electrophotographic image forming apparatus, and the cartridge drum positioning recess is disposed at a center of the cartridge coupling and the circular projected portion.