Powder conveying device, developing device, process cartridge, and image forming apparatus

• US 7,787,784 B2
• Filed: 07/20/2007
• Issued: 08/31/2010
• Est. Priority Date: 07/31/2006
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Hori, Eisuke
• Primary Examiner(s): Brase; Sandra L
• Application Number:
  US11/780,674
• Publication Number:
  US 20080025743A1
• Time in Patent Office: 1,138 Days
• Field of Search: 399/27, 399/30, 399/61, 399/258, 399/260, 399/16, 399/381
• US Class Current: 399/27
• CPC Class Codes: G03G 15/0856 Detection or control means for the developer level
• CPC Class Codes: G03G 15/0877 Arrangements for metering and dispensing developer from a developer cartridge into the development unit
• CPC Class Codes: G03G 15/0879 for dispensing developer from a developer cartridge not directly attached to the development unit
• CPC Class Codes: G03G 15/0886 by mechanical means, e.g. shutter, plug
• CPC Class Codes: G03G 2215/0634 Developing device
• CPC Class Codes: G03G 2215/0802 Arrangements for agitating or circulating developer material

Abstract

A powder conveying device includes a powder container, a powder conveying tube, a powder conveying member, and a detecting unit. The powder container is configured to contain powder. The powder conveying tube guides the powder from the powder container to a conveyance destination located downward from the powder container. The powder conveying member is located inside the powder conveying tube, and moves to convey the powder toward downstream in a conveying direction. The detecting unit is located in the powder conveying tube, and detects a remaining amount of powder. Time t2 taken to convey the maximum amount of powder satisfies t2<t1 where t1 is the sum of time required to feed recording sheets and time interval between feeding of the recording sheets.

Claims

1. A powder conveying device comprising:

a powder container that is configured to contain powder;

a powder conveying path that guides the powder from the powder container to a conveyance destination located downward relative to the powder container;

a powder conveying member that is located inside the powder conveying path, and moves to apply a force to the powder to convey the powder toward downstream in a conveying direction; and

a detecting unit that is located in the powder conveying path, and detects a remaining amount of powder, wherein

a first time interval between feeding of recording sheets for successive printing of images with a large image area is set longer than a second time interval between feeding of recording sheets for the normal printing.

2. The powder conveying device according to claim 1, wherein the first time interval is set longer than the second time interval by at least 0.1 second.

3. The powder conveying device according to claim 2, wherein the images with the large image area have an area at least 80 percent of which is occupied by the image area.

4. A developing device comprising the powder conveying device according to claim 1.

5. A process cartridge comprising the developing device according to claim 4.

6. An image forming apparatus comprising the developing device according to claim 4.

7. A process cartridge comprising the powder conveying device according to claim 1.

8. An image forming apparatus comprising the process cartridge according to claim 7.

9. An image forming apparatus comprising the powder conveying device according to claim 1.

10. The powder conveying device according to claim 1, wherein the large image area is larger than an image area of sheets having normal printing.

11. The powder conveying device according to claim 1, wherein the images with the large image area have an area at least 80 percent of which is occupied by the image area.

12. The powder conveying device according to claim 1, wherein the powder conveying path comprises a powder conveying tube.