DEVELOPMENT DEVICE

• US 20090257763A1
• Filed: 04/08/2009
• Published: 10/15/2009
• Est. Priority Date: 04/11/2008
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: HAYASHI, Shigeki
• Granted Patent: US 8,103,179 B2
• Time in Patent Office: Days
• US Class Current: 399/53
• CPC Class Codes: G03G 15/0848 Arrangements for testing or measuring developer properties or quality, e.g. charge, size, flowability
• CPC Class Codes: G03G 15/0877 Arrangements for metering and dispensing developer from a developer cartridge into the development unit
• CPC Class Codes: G03G 15/0891 for conveying or circulating developer, e.g. augers
• CPC Class Codes: G03G 2215/0634 Developing device

Abstract

A development device is provided with: a development roller that rotates while carrying a two-component developer in a development tank accommodating the two-component developer; a tubular developer conveyance path having therein a conveyance mechanism that conveys the two-component developer in an axial direction of the development roller; a developer supply mouth for supplying the two-component developer to the developer conveyance path; a developer discharge mouth for discharging the two-component developer from the developer conveyance path; a supply mouth adjustment member that adjusts the area of the opening of the developer supply mouth; and a control unit that causes the supply mouth adjustment member to operate based on the fluidity of the two-component developer in the development tank.

Claims

1. A development device, comprising.

a development roller that rotates while carrying a two-component developer in a development tank accommodating the two-component developer;

a tubular developer conveyance path having therein a conveyance mechanism that conveys the two-component developer in an axial direction of the development roller;

a developer supply mouth for supplying the two-component developer to the developer conveyance path;

a developer discharge mouth for discharging the two-component developer from the developer conveyance path;

a supply mouth adjustment member that adjusts an area of an opening of the developer supply mouth; and

a control unit that causes the supply mouth adjustment member to operate based on information on the two-component developer in the development tank.

2. The development device according to claim 1, wherein

the control unit increases the area of the opening of the developer supply mouth as a cumulative use time of the two-component developer increases.

3. The development device according to claim 2, wherein

the control unit determines the cumulative use time of the two-component developer based on the number of times an electrostatic latent image on a latent image carrier is developed.

4. The development device according to claim 1, further comprising:

a detection unit that detects a fluidity of the two-component developer in the development tank,

wherein the control unit controls the area of the opening of the developer supply mouth based on the fluidity of the two-component developer detected by the detection unit.

5. The development device according to claim 4, wherein

when the fluidity of the two-component developer detected by the detection unit is higher than a predetermined level, the control unit decreases the area of the opening of the developer supply mouth.

6. The development device according to claim 4, wherein

when the fluidity of the two-component developer detected by the detection unit is lower than a predetermined level, the control unit increases the area of the opening of the developer supply mouth.

7. The development device according to claim 1, wherein

the developer supply mouth and the developer discharge mouth are provided at one end and at the other end in the axial direction of the development roller, respectively.

8. The development device according to claim 1, wherein

a restricting member that restricts an amount of two-component developer carried by the development roller and a flow plate that lets an excessive two-component developer restricted by the restricting member flow in a direction away from a peripheral surface of the development roller are provided in the development tank, the developer conveyance path is provided on a bottom side of the flow plate, and the developer supply mouth is formed on the flow plate.