US 2026/0099121 A1 · PROCESS UNIT AND IMAGE FORMING APPARATUS

Abstract

A process unit includes a rotatable image bearing member, a charging roller configured to come into contact with a surface of the image bearing member and to charge the surface, a brush unit including a brush configured to come into contact with a surface of the charging roller at a contact position and a holding member configured to hold the brush, a frame member configured to swingably support the holding member about a swing axis, and a regulation member configured to abut the holding member at an abutment position and regulate a position of the holding member in a rotational direction about the swing axis. As viewed in a rotation axis direction of the charging roller, the abutment position is positioned between the contact position and the swing axis in a tangent direction of the charging roller at the contact position.

Claims32

Dependent claims

A process unit comprising:

a rotatable image bearing member;
a charging roller configured to come into contact with a surface of the image bearing member and to charge the surface;
a brush unit including a brush configured to come into contact with a surface of the charging roller at a contact position and a holding member configured to hold the brush;
a frame member configured to swingably support the holding member about a swing axis;
and
a regulation member configured to abut the holding member at an abutment position and regulate a position of the holding member in a rotational direction about the swing axis,
wherein as viewed in a rotation axis direction of the charging roller, the abutment position is positioned between the contact position and the swing axis in a tangent direction of the charging roller at the contact position.

4 more elements

An image forming apparatus comprising:

a rotatable image bearing member;
a charging roller configured to come into contact with a surface of the image bearing member and to charge the surface;
an exposing unit configured to irradiate the image bearing member with light such that a latent image is formed on the surface of the image bearing member;
a brush unit including (i) a brush including a plate-shaped brush substrate and brush bristles protruding from the brush substrate and configured to come into contact with the surface of the charging roller, (ii) a brush holding portion configured to hold the brush substrate, and (iii) an extending portion extending in a direction intersecting with a rotation axis direction of the charging roller from one end portion of the brush holding portion in the rotation axis direction;
and
a frame member configured to support the extending portion,
wherein the extending portion overlaps an optical path of the light from the exposing unit to the image bearing member as viewed in the rotation axis direction.

4 more elements

A process unit comprising:

a rotatable image bearing member;
a charging roller configured to come into contact with a surface of the image bearing member and to charge the surface;
a brush unit including (i) a brush including a plate-shaped brush substrate and brush bristles protruding from the brush substrate and configured to come into contact with the surface of the charging roller, (ii) a brush holding portion configured to hold the brush substrate, and (iii) a swing support portion extending in a direction intersecting with a rotation axis direction of the charging roller from one end portion of the brush holding portion in the rotation axis direction;
and
a frame member configured to support the swing support portion,
wherein in a case where a cross-section including a center of the brush in the rotation axis direction and orthogonal to the rotation axis direction is viewed in the rotation axis direction, at least part of the swing support portion protrudes downstream in a rotation direction of the image bearing member in image formation with respect to an imaginary straight line passing through a center of the image bearing member and a most downstream end portion of the brush holding portion in the rotation direction in the cross-section.

3 more elements

Dependencies are inferred from the claim text.

Process unit and image forming apparatus

Life of this patent

Process unit and image forming apparatus

Life of this patent

Abstract

Claims32