Image forming apparatus having a detachable cartridge including a photoconductive drum with axis shaft having a minimal rotational eccentricity, and a method of assembling the image forming apparatus

An image forming apparatus, comprising:

• forming means for forming an image;
• bearing means for bearing the image formed by the forming means, the bearing means being in a hollow cylindrical shape and having first and second open end portions and an intermediate hollow portion arranged between and communicating with the first and second open end portions, and comprising;
• a first flange including a first opening at a center portion thereof and arranged at the first open end portion of the bearing means;
• and
• a second flange including a second opening at a center portion thereof and arranged at the second open end portion of the bearing means;
• and
• carrying means for carrying the bearing means,
• wherein the bearing means and the carrying means are unified in one unit and configured to be detachably provided to the image forming apparatus.

A method for assembling an image forming apparatus, comprising the steps of:

• providing an image bearing member formed in a hollow cylindrical shape and having first and second open end portions and intermediate hollow portion arranged between and communicating with the first and second open end portions;
• arranging a first flange including a first opening at a center portion thereof at the first open end portion of the image bearing member;
• arranging a second flange including a second opening at a center portion thereof at the second open end portion of the image bearing member;
• preparing a through shaft;
• inserting the through shaft into the image bearing member through the first opening of the first flange, the intermediate hollow portion, and the second opening of the second flange;
• engaging the through shaft with the image bearing member;
• and
• mounting the image bearing member engaged with the through shaft detachably to the image forming apparatus.

A process cartridge detachably provided to an image forming apparatus, comprising:

• an image forming mechanism;
• and
• an image bearing mechanism detachably provided to the image forming apparatus, the image bearing mechanism comprising:
• an image bearing member configured to bear an electrostatic latent image;
• and
• a through shaft configured to support the image bearing member.

A process cartridge detachably provided to an image forming apparatus, comprising:

• bearing means for bearing the image formed by the forming means, the bearing means being in a hollow cylindrical shape and having first and second open end portions and an intermediate hollow portion arranged between and communicating with the first and second open end portions, and comprising;
• a first flange including a first opening at a center portion thereof and arranged at the first open end portion of the bearing means;
• and
• a second flange including a second opening at a center portion thereof and arranged at the second open end portion of the bearing means;
• and
• carrying means for carrying the bearing means,
• wherein the bearing means and the carrying means are unified in one unit and configured to be detachably provided to the image forming apparatus.

A method for assembling a process cartridge, comprising the steps of:

• providing an image bearing member formed in a hollow cylindrical shape and having first and second open end portions and an intermediate hollow portion arranged between and communicating with the first and second open end portions;
• arranging a first flange including a first opening at a center portion thereof at the first open end portion of the image bearing member;
• arranging a second flange including a second opening at a center portion thereof at the second open end portion of the image bearing member;
• preparing a through shaft;
• inserting the through shaft into the image bearing member through the first opening of the first flange, the intermediate hollow portion, and the second opening of the second flange;
• engaging the through shaft with the image bearing member;
• and
• mounting the image bearing member engaged with the through shaft detachably to the process cartridge.