Process unit and image forming apparatus

A process unit comprising:

• a rotatable image bearing member;
• a charging roller configured to come in contact with a surface of the image bearing member and configured to charge the surface;
• a brush unit including a brush and a holding member, the brush including a plate-shaped brush substrate and brush bristles protruding from the brush substrate, the holding member being configured to hold the brush substrate and movable such that the brush substrate moves closer to and away from the charging roller;
• a regulation member configured to abut the holding member to regulate a position of the holding member;
• and
• an urging member configured to urge the holding member such that the brush bristles come into contact with a surface of the charging roller and the holding member abuts the regulation member,
• wherein in a case where a direction that is parallel to a thickness direction of the brush substrate and directed from the brush substrate toward the charging roller is referred to as a first direction and a direction opposite to the first direction is referred to as a second direction,
• the holding member includes a first force-receiving portion configured to receive a force in the first direction from the urging member, a second force-receiving portion configured to receive a force in the second direction from the regulation member, and a third force-receiving portion configured to receive a force in the second direction from the brush substrate in a case where the brush bristles receive a reaction force from the surface of the charging roller, and
• the first force-receiving portion, the second force-receiving portion, and the third force-receiving portion are disposed on one end side with respect to a center of the holding member in a rotation axis direction of the charging roller, and are arranged in an order of the second force-receiving portion, the first force-receiving portion, and the third force-receiving portion from the one end toward the center.