Developing device and image forming apparatus

Abstract

A developing device includes a developer tank, a developing roller, a supply roller, a stirring member, and a doctor blade. The developing device is provided with: a cleaning member detachably provided on a contact portion of the doctor blade with the developing roller, which slides to rub a surface of the doctor blade upon contacting; a supporting section for supporting the cleaning member so as to be capable of being attached to and detached from the contact portion of the doctor blade with the developing roller; and a driving mechanism for moving the cleaning member so as to be attached to and detached from the contact portion of the doctor blade with the developing roller.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

Other and further objects, features, and advantages of the invention will be more explicit from the following detailed description taken with reference to the drawings wherein:

FIG. 1 is a sectional view schematically showing a configuration of a developing device according to a first embodiment of the invention;

FIG. 2 is a sectional view showing the developing device shown in FIG. 1, in which a cleaning member is positioned at its contact position with a doctor blade;

FIG. 3 is a sectional view schematically showing a configuration of chief part of a developing device according to a second embodiment of the invention;

FIG. 4 is a sectional view schematically showing a configuration of chief part of a developing device according to a third embodiment of the invention;

FIG. 5 is a sectional view schematically showing a configuration of chief part of a developing device according to a fourth embodiment of the invention;

FIG. 6 is a top view showing a configuration of chief part of a cleaning member used in the developing device shown in FIG. 5; and

FIG. 7 is a sectional view schematically showing a configuration of an image forming apparatus according to another embodiment of the invention.

Claims

1. A developing device provided in an electrophotographic image forming apparatus, comprising: a developer tank having an internal space for containing a toner;a developing roller for carrying a toner layer on a surface thereof and supplying a toner to an electrostatic latent image on a photoreceptor drum;a doctor blade in contact with a surface of the developing roller, for regulating a layer thickness of the toner layer on the surface; anda cleaning member composed of a platy member, the cleaning member being disposed so that one end of the cleaning member extends in parallel with an axis line of the developing roller and makes angular contact with a contact portion of the doctor blade with the developing roller and its adjacent portion of the doctor blade while another end of the cleaning member is inserted into a through hole formed in a developer tank wall of the developer tank and extends to outside of the developer tank.

2. The developing device of claim 1, wherein the developer tank wall is in a vertical direction of the developer tank, a through hole is formed in an upper part of the developer tank wall, and the other end of the cleaning member is inserted into the through hole and extends upwardly in the vertical direction of the developer tank.

3. The developing device of claim 1, further comprising: a supporting section having at least a part provided inside the developer tank, which supports the cleaning member so as to be detachable from the contact portion of the doctor blade with the developing roller and its adjacent portion of the doctor blade; anda driving mechanism which moves the cleaning section to be attached to and detached from the contact portion and its adjacent portion of the doctor blade.

4. The developing device of claim 3, wherein the driving mechanism comprises: a rotary driving section which rotates; anda drive transmitting section having one end coupled to the rotary driving section and another end coupled to the cleaning member, which converts a rotary drive caused by the rotary driving section into a reciprocal linear drive and transmits the reciprocal linear drive to the cleaning member,wherein the cleaning member is driven by the reciprocal linear drive transmitted from the drive transmitting section to be attached to and detached from the contact portion and the adjacent portion of the doctor blade.

5. The developing device of claim 1, wherein a tip of the cleaning member in contact with the doctor blade is formed into a hook shape which is bent in a rotational direction of circumference of the developing roller.

6. The developing device of claim 1, wherein at least the tip of the cleaning member in contact with the doctor blade is brush-shaped.

7. The developing device of claim 1, wherein the cleaning member is of a resin sheet.

8. The developing device of claim 7, wherein the resin sheet is divided into plural pieces in a longitudinal direction of the developer tank.

9. The developing device of claim 1, wherein the cleaning member comprises: a first platy member which is inserted into the through hole formed in the developer tank wall and extends to outside of the developer tank; anda second platy member which extends toward the doctor blade inside the developer tank and is detachable from the doctor blade,wherein a side end portion of the first platy member extending in parallel with an axis line of the developing roller inside the developer tank is coupled to a side end portion of the second platy member which extends in parallel with the axis line of the developing roller and is located on an opposite side of a side end portion of the second platy member facing the doctor blade.

10. The developing device of claim 1, wherein a tip of the doctor blade in contact with the surface of the developing roller is formed into a hook shape which is bent in an outward direction from the contact portion with the developing roller.

11. An electrophotographic image forming apparatus comprising: a photoreceptor drum;a charging section;an exposing section;a developing section;a transfer section; anda fixing section,wherein the developing section is the developing device of claim 1.