Positioning member, holding device, process cartridge, and image forming apparatus

2:

• The positioner according to claim 1,
• wherein the abutting region of the groove includes an arc-shaped surface region having substantially a same diameter as an outer diameter of the shaft.

3:

• The positioner according to claim 1,
• wherein the abutting region of the groove includes a face formed in an arc shape around a rotation center of the receiver.

4:

• The positioner according to claim 1,
• wherein the abutting region of the groove includes two surface regions whose facing distance gradually decreases toward the receiver.

5:

• The positioner according to claim 1,
• wherein the predetermined direction is a direction in which an imaginary line passing through a center of the receiver and a center of the abutting region extends.

6:

• The positioner according to claim 1,
• wherein the restrictor includes an elastic structure to bias the shaft toward the projection.

8:

• The positioner according to claim 7,
• wherein the leaf spring includes a convex region to make point contact with the shaft disposed at the abutting region.

9:

• The positioner according to claim 7,
• wherein the positioner includes a fixing region into which a tip of the pressing region of the leaf spring having passed through the groove is inserted and fixed.

12:

• The process cartridge according to claim 10, wherein a developing bias is applied to the shaft of the developer bearer via the restrictor of the positioner.

13:

• An image forming apparatus, comprising the positioner according to claim 1,
• wherein the positioner is detachably disposed in the image forming apparatus.

15:

• The holder according to claim 14, wherein the section to restrict of the housing includes two walls facing each other with the shaft interposed between the two walls.

16:

• The holder according to claim 15, wherein each of the two walls is parallel to an imaginary line passing through a rotation center of the first rotating body and a rotation center of the second rotating body when viewed in a cross-section orthogonal to the rotation center of the first rotating body.

17:

• The holder according to claim 15,
• wherein each of the two walls protrudes in a direction away from the first rotating body with respect to the housing, and
• wherein a base of the two walls is disposed at a position closer to the first rotating body than an abutting region at which the positioner abuts on the shaft.

18:

• The holder according to claim 15,
• wherein one end of the restrictor is held by one of the two walls, and another end of the restrictor is fitted into a recess in another one of the two walls to restrict movement in a direction away from the first rotating body.

20:

• The holder according to claim 14,
• wherein the positioner is disposed in the housing such that the facing distance between the first rotating body and the second rotating body is adjustable adjusted.