Image Forming Apparatus and Developer Cartridge

Abstract

A developer cartridge includes a developer cartridge case for accommodating a developer, a developing roller, a toner layer thickness control blade, and a side sealing member. The developing roller is supported by the developer cartridge case such that a circumferential surface thereof is exposed to an outside of the developer cartridge case along a width direction. The toner layer thickness control blade includes a blade body portion made of a metallic plate. A tip portion of the blade body portion is disposed at a sliding portion of the developing roller and the side sealing member so as to contact with the side sealing member. A frictional heat generated at the sliding portion is released to the outside of the developer cartridge case through the blade body portion in order restrain a leak of the developer as much as possible.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments of the invention in conjunction with the accompanying drawings, in which:

FIG. 1 is a cross-sectional side view of a color laser printer, which is an embodiment of an image forming apparatus of the present invention;

FIG. 2 is an external view of a developer cartridge shown in FIG. 1, as viewed from a rear side of the developer cartridge;

FIG. 3 is an external view of the developer cartridge shown in FIG. 1, as viewed from an obliquely downward side (from a side of the developing roller-exposure opening);

FIG. 4 is a cross-sectional view taken on line A-A in FIG. 3;

FIG. 5 is an external view of the developer cartridge case shown in FIG. 3, in a state where a developing roller and a side guard member are removed;

FIG. 6 is a cross-sectional view illustrating a configuration of a modified example of the developer cartridge shown in FIG. 4; and

FIG. 7 is a cross-sectional enlarged view of a substantial portion of the modified developer cartridge shown in FIG. 6.

Claims

1. An image forming apparatus configured so as to arrange fine particles of a developer in an image-wise manner at an image-forming section to form an image by said developer onto a recording medium, said image forming apparatus comprising: a body frame;a developer-supply section accommodated within said body frame, said developer-supply section being configured so as to be capable of accommodating said developer and supplying said accommodated developer to said image forming section; anda recording-medium-transport mechanism configured so as to transport said recording medium along a predetermined transport path, while attaching said developer onto said recording medium,wherein said developer-supply section comprises:a developer-carrying member formed to have a substantially cylindrical shape having a central axis in a direction perpendicular to a transport direction of said recording medium by means of said recording-medium-transport mechanism;a developer-accommodation section configured so as to be capable of accommodating said developer-carrying member and said developer and to have an opening section which enables a part of a circumferential surface of said developer-carrying member to be exposed along said central axis;a sealing member which is provided so as to be interposed between an end portion in said direction of said central axis of said developer-carrying member and said developer-accommodation section, and is configured so as to slide on said circumferential surface of said developer-carrying member to thereby be capable of restraining a leak of said developer from said opening section to an outside of said developer-accommodation section; anda heat-release member having good heat conductance, said heat-release member being provided so as to extend toward an outside from a sliding portion of said circumferential surface of said developer-carrying member and said sealing member to thereby be capable of releasing a frictional heat which is generated on said sealing member at said sliding portion.

2. An image forming apparatus according to claim 1, wherein said developer-supply section further comprises a developer-carrying-amount control member which includes a control-member body section composed of a metallic plate as said heat-release member, and a developer-carrying-amount control section provided at a tip portion of said control-member body section and configured so as to be capable of adjusting a carrying amount of said developer on said circumferential surface of said developer-carrying member by contacting with said circumferential surface, and said developer-carrying-amount control member is fixed to said developer-accommodation section in such a manner that said sealing member contacts with said control-member body section.

3. An image forming apparatus according to claim 2, wherein said sealing member comprises: a sliding member which is a sheet-like member having a surface of low coefficient of friction and is disposed so as to contact with said circumferential surface at said end portion of said developer-carrying member; anda sealing body which is attached to said sliding member and said developer-accommodation section and is composed of a foamable synthetic resin having an elasticity so as to be able to bias said sliding member toward said circumferential surface of said developer-carrying member, and whereinsaid developer-carrying-amount control member is disposed in such a manner that said control-member body section contacts with said sliding member.

4. An image forming apparatus according to claim 3, further comprising an auxiliary sealing member which is provided so as to be interposed between said control-member body section and said developer-carrying member.

5. An image forming apparatus according to claim 2, further comprising an auxiliary sealing member which is provided so as to be interposed between said control-member body section and said developer-carrying member.

6. An image forming apparatus according to claim 1, wherein said sealing member comprises: a sliding member which is a sheet-like member having a surface of low coefficient of friction and is disposed so as to contact with said circumferential surface at said end portion of said developer-carrying member;a metallic sheet for heat-release as said heat-release member, which is composed of a thin metallic plate set to be attached to said sliding member; anda sealing body which is composed of a foamable synthetic resin having an elasticity so as to be able to bias said sliding member toward said circumferential surface of said developer-carrying member and is attached to said metallic sheet and said developer-accommodation section.

7. An image forming apparatus according to claim 6, wherein said sealing member is configured in such a manner that said metallic sheet is exposed toward space outside of said developer-accommodation section at outside of said opening section.

8. A developer cartridge configured so as to accommodate a developer and to be capable of supplying said developer to an image-forming section at which fine particles of said developer is to be arranged in an image-wise manner in a body frame of an image forming apparatus, said developer cartridge being removably attached to said body frame, comprising, a developer-carrying member formed to have a substantially cylindrical shape;a developer-accommodation section configured so as to be capable of accommodating said developer-carrying member and said developer and to have an opening section which enables a part of a circumferential surface of said developer-carrying member to be exposed along a central axis of said substantially cylindrical shape;a sealing member which is provided so as to be interposed between an end portion in a direction of said central axis of said developer-carrying member and said developer-accommodation section, and is configured so as to slide on said circumferential surface of said developer-carrying member to thereby be capable of restraining a leak of said developer from said opening section to an outside of said developer-accommodation section; anda heat-release member which has good heat conductance and is provided so as to extend toward an outside from a sliding portion of said circumferential surface of said developer-carrying member and said sealing member to thereby be capable of releasing a frictional heat generated on said sealing member at said sliding portion.

9. A developer cartridge according to claim 8, further comprising a developer-carrying-amount control member which includes a control-member body section composed of a metallic plate as said heat-release member, and a developer-carrying-amount control section provided at a tip portion of said control-member body section and configured so as to be capable of adjusting a carrying amount of said developer on said circumferential surface of said developer-carrying member by contacting with said circumferential surface, and wherein said developer-carrying-amount control member is fixed to said developer-accommodation section in such a manner that said sealing member contacts with said control-member body section.

10. A developer cartridge according to claim 9, wherein said sealing member comprises:a sliding member which is a sheet-like member having a surface of low coefficient of friction and is disposed so as to contact with said circumferential surface at said end portion of said developer-carrying member; anda sealing body which is attached to said sliding member and said developer-accommodation section and is composed of a foamable synthetic resin having an elasticity so as to be able to bias said sliding member toward said circumferential surface of said developer-carrying member, and whereinsaid developer-carrying-amount control member is disposed in such a manner that said control-member body section contacts with said sliding member.

11. A developer cartridge according to claim 10, further comprising an auxiliary sealing member which is provided so as to be interposed between said control-member body section and said developer-carrying member.

12. A developer cartridge according to claim 9, further comprising an auxiliary sealing member which is provided so as to be interposed between said control-member body section and said developer-carrying member.

13. A developer cartridge according to claim 8, wherein said sealing member comprises: a sliding member which is a sheet-like member having a surface of low coefficient of friction and is disposed so as to contact with said circumferential surface at said end portion of said developer-carrying member;a metallic sheet for heat-release as said heat-release member, which is composed of a thin metallic plate set to be attached to said sliding member; anda sealing body which is composed of a foamable synthetic resin having an elasticity so as to be able to bias said sliding member toward said circumferential surface of said developer-carrying member and is attached to said metallic sheet and said developer-accommodation section.

14. A developer cartridge according to claim 13, wherein said sealing member is configured in such a manner that said metallic sheet is exposed toward space outside of said developer-accommodation section at outside of said opening section.