Photosensitive member unit and development unit

A development unit mountable on a photosensitive member unit including a photosensitive member and configured to be attachable to and detachable from an image forming apparatus, the development unit comprising:

• a development roller;
• a developer accommodation portion;
• a first agitation member and a second agitation member each configured to agitate toner accommodated in the developer accommodation portion;
• and
• a pressed portion configured to be pressed by a pressing portion of the photosensitive member unit when the development unit is mounted on the photosensitive member unit,
• wherein the development roller is pressed by being pressed at the pressed portion and urged toward the photosensitive member,
• wherein a rotation center of the second agitation member is disposed at a position farther from the development roller than a rotation center of the first agitation member is, and
• wherein a distance from a contact portion to contact the photosensitive member of the development roller to the pressed portion is longer than a distance from the contact portion to the rotation center of the second agitation member.

A development unit mountable on a photosensitive member unit including a photosensitive member and configured to be attachable to and detachable from an image forming apparatus, the development unit comprising:

• a development roller;
• and
• a first pressed portion and a second pressed portion each configured to be pressed by a pressing portion of the photosensitive member unit when the development unit is mounted on the photosensitive member unit,
• wherein the first pressed portion and the second pressed portion are disposed at different positions in an axial direction of the development roller,
• wherein the development roller is pressed at the first pressed portion and the second pressed portion and urged against the photosensitive member, and
• wherein a distance from a contact portion to contact the photosensitive member of the development roller to the first pressed portion is longer than a distance from the contact portion to the second pressed portion in a pressing direction in which the first pressed portion and the second pressed portion are pressed by the pressing portion.

A photosensitive member unit comprising:

• a photosensitive member;
• a mounting portion capable of mounting a development unit thereon;
• two side walls disposed to sandwich a toner accommodation portion of the development unit mounted on the mounting portion in an axial direction of the photosensitive member;
• a movable member configured to press and move the development unit mounted on the mounting portion;
• and
• an operation portion provided on the movable member and configured to receive a force for pressing and moving the development unit mounted on the mounting portion,
• wherein the operation portion is disposed on one end side in the axial direction of the photosensitive member, and
• wherein an outermost end of the operation portion is disposed on an outer side of one of the two side walls disposed at the one end in the axial direction of the photosensitive member.

A photosensitive member unit, comprising:

• a photosensitive member;
• a mounting portion capable of mounting thereon a development unit including a development roller;
• a pressing member configured to press the development unit mounted on the mounting portion and cause the development roller to contact the photosensitive member,
• a movable member configured to press and move the development unit mounted on the mounting portion;
• and
• an operation portion provided on the movable member and configured to receive a force to press and move the development unit mounted on the mounting portion,
• wherein the operation portion is disposed at a position where the operation portion overlaps the pressing member when the operation portion and the pressing member are projected on a horizontal plane in a state where the photosensitive member unit is placed on the horizontal plane.

A development unit capable of mounting thereon a photosensitive member unit including a photosensitive member, the development unit comprising:

• a housing including a side wall;
• a rotary member rotatably supported on the housing;
• a projection formed to project from the side wall in a rotational axis direction of the rotary member;
• a bearing portion provided on an inner peripheral surface of the projection and configured to rotatably support the rotary member;
• and
• a contact portion provided on an outer peripheral surface of the projection and configured to contact to be pressed by a movable member of the photosensitive member unit when the development unit is detached from the photosensitive member unit.

A development unit capable of mounting on a photosensitive member unit including a photosensitive member, the development unit comprising:

• a housing including a side wall;
• a rotary member rotatably supported on the housing;
• a first projection and a second projection each formed to project from the side wall in a rotational axis direction of the rotary member;
• a bearing portion provided on an inner peripheral surface of the first projection and configured to rotatably support the rotary member;
• a contact portion provided on an outer peripheral surface of the second projection and configured to contact to be pressed by a movable member of the photosensitive member unit when the development unit is detached from the photosensitive member unit;
• and
• an intermediate portion provided to project from the side wall in a rotational axis direction of the rotary member and connecting the first projection and the second projection.

A development unit capable of mounting on a photosensitive member unit including a photosensitive member, the development unit comprising:

• a development roller;
• an accommodation portion configured to accommodate toner;
• a first agitation member and a second agitation member each configured to agitate the toner accommodated in the accommodation portion;
• and
• a contact portion configured to contact a movable member of the photosensitive member unit to be pressed thereby when the development unit is detached from the photosensitive member unit,
• wherein a rotation center of the first agitation member is closer to a rotation center of the development roller than a rotation center of the second agitation member is as viewed along an axial direction of the development roller, and
• wherein the rotation center of the first agitation member is closer to the rotation center of the development roller than the contact portion is as viewed along the axial direction of the development roller.