Developing device and image forming apparatus

• US 9,459,558 B1
• Filed: 10/02/2015
• Issued: 10/04/2016
• Est. Priority Date: 04/20/2015
• Status: Active Grant

• Current Assignee: Fujifilm Business Innovation Corp. (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Xerox Company Limited (Xerox Holdings Corp.)
• Inventors: Onuki, Tomio, Kato, Masanori, Tanaka, Yoshinori
• Primary Examiner(s): Hyder, G. M.
• Application Number:
  US14/873,442
• Publication Number:
  US 20160306297A1
• Time in Patent Office: 368 Days
• US Class Current: 1/1
• CPC Class Codes: G03G 15/0891 for conveying or circulating developer, e.g. augers
• CPC Class Codes: G03G 15/0893 in a closed loop within the sump of the developing device

Abstract

Provided is a developing device including a container that accommodates a developer, a developer holding member that develops the electrostatic latent image on the image holding member by delivering the developer to a position facing the image holding member, while rotating, a first transport member that extends in a direction of a rotary shaft of the developer holding member, and that transports the developer inside the container in a first direction, and a pushing-back member that pushes back the developer transported in the first direction by the first transport member in a direction opposite to the first direction, and that allows an amount of the developer beyond pushing-back capacity within the developer transported in the first direction, to exit from the container, wherein the container includes a control wall that controls passage of the developer.

Claims

1. A developing device comprising:

a container that accommodates a developer;

a developer holding member that is arranged so that a region close to an image holding member for holding an electrostatic latent image is exposed from the container, and that develops the electrostatic latent image on the image holding member by delivering the developer to a position facing the image holding member, while rotating;

a first transport member that extends in a direction of a rotary shaft of the developer holding member, and that transports the developer inside the container in a first direction; and

a pushing-back member that is arranged ahead of the first transport member in the first direction, that pushes back the developer transported in the first direction by the first transport member in a direction opposite to the first direction, and that allows an amount of the developer beyond pushing-back capacity within the developer transported in the first direction, to exit from the container,

wherein the container includes a control wall that controls passage of the developer by protruding from an inner wall surface forming a space through which the developer passes, in a shape extending in a direction intersecting the first direction, in the space, and the control wall adopts a downward protruding posture.

2. The developing device according to claim 1,

wherein the control wall is formed in a boundary region where both the first transport member and the pushing-back member are arranged on an inner wall surface of the container.

3. The developing device according to claim 2,

wherein a wall surface of the control wall which faces an upstream side in the first direction is a tilting surface that tilts to a downstream side in the first direction, in accordance with the wall surface protruding from the inner wall surface of the container.

4. The developing device according to claim 3,

wherein the control wall is formed at a plurality of locations with a space therebetween in the first direction.

5. The developing device according to claim 4,

wherein the first transport member includes a first spindle which extends in the direction of the rotary shaft and a first spiral vane which is formed around the first spindle, and transports the developer in the first direction by the first spiral vane using rotation of the first spindle,

wherein the developing device further comprises a second transport member that is arranged parallel to the first transport member, that includes a second spindle which extends in the direction of the rotary shaft and a second spiral vane which is formed around the second spindle and which is spirally formed on a same cycle as the first spiral vane, and that transports the developer in a second direction opposite to the first direction by the second spiral vane using rotation of the second spindle,

wherein the container includes a partition wall that partitions a first chamber in which the first transport member is arranged and a second chamber in which the second transport member is arranged, and a developer flow path that connects the first chamber and the second chamber which are respectively formed in both end portions of the first transport member and the second transport member, and

wherein the first transport member and the second transport member are arranged in a phase when both the first spiral vane and the second spiral vane simultaneously open a front surface of the flow path on a pushing-back member side within the flow path.

6. The developing device according to claim 3,

wherein the first transport member includes a first spindle which extends in the direction of the rotary shaft and a first spiral vane which is formed around the first spindle, and transports the developer in the first direction by the first spiral vane using rotation of the first spindle,

wherein the developing device further comprises a second transport member that is arranged parallel to the first transport member, that includes a second spindle which extends in the direction of the rotary shaft and a second spiral vane which is formed around the second spindle and which is spirally formed on a same cycle as the first spiral vane, and that transports the developer in a second direction opposite to the first direction by the second spiral vane using rotation of the second spindle,

wherein the container includes a partition wall that partitions a first chamber in which the first transport member is arranged and a second chamber in which the second transport member is arranged, and a developer flow path that connects the first chamber and the second chamber which are respectively formed in both end portions of the first transport member and the second transport member, and

wherein the first transport member and the second transport member are arranged in a phase when both the first spiral vane and the second spiral vane simultaneously open a front surface of the flow path on a pushing-back member side within the flow path.

7. The developing device according to claim 2,

wherein the control wall is formed at a plurality of locations with a space therebetween in the first direction.

8. The developing device according to claim 7,

wherein the first transport member includes a first spindle which extends in the direction of the rotary shaft and a first spiral vane which is formed around the first spindle, and transports the developer in the first direction by the first spiral vane using rotation of the first spindle,

wherein the developing device further comprises a second transport member that is arranged parallel to the first transport member, that includes a second spindle which extends in the direction of the rotary shaft and a second spiral vane which is formed around the second spindle and which is spirally formed on a same cycle as the first spiral vane, and that transports the developer in a second direction opposite to the first direction by the second spiral vane using rotation of the second spindle,

wherein the container includes a partition wall that partitions a first chamber in which the first transport member is arranged and a second chamber in which the second transport member is arranged, and a developer flow path that connects the first chamber and the second chamber which are respectively formed in both end portions of the first transport member and the second transport member, and

wherein the first transport member and the second transport member are arranged in a phase when both the first spiral vane and the second spiral vane simultaneously open a front surface of the flow path on a pushing-back member side within the flow path.

9. The developing device according to claim 2,

wherein the first transport member includes a first spindle which extends in the direction of the rotary shaft and a first spiral vane which is formed around the first spindle, and transports the developer in the first direction by the first spiral vane using rotation of the first spindle,

wherein the developing device further comprises a second transport member that is arranged parallel to the first transport member, that includes a second spindle which extends in the direction of the rotary shaft and a second spiral vane which is formed around the second spindle and which is spirally formed on a same cycle as the first spiral vane, and that transports the developer in a second direction opposite to the first direction by the second spiral vane using rotation of the second spindle,

wherein the container includes a partition wall that partitions a first chamber in which the first transport member is arranged and a second chamber in which the second transport member is arranged, and a developer flow path that connects the first chamber and the second chamber which are respectively formed in both end portions of the first transport member and the second transport member, and

wherein the first transport member and the second transport member are arranged in a phase when both the first spiral vane and the second spiral vane simultaneously open a front surface of the flow path on a pushing-back member side within the flow path.

10. The developing device according to claim 1,

wherein a wall surface of the control wall which faces an upstream side in the first direction is a tilting surface that tilts to a downstream side in the first direction, in accordance with the wall surface protruding from the inner wall surface of the container.

11. The developing device according to claim 10,

wherein the control wall is formed at a plurality of locations with a space therebetween in the first direction.

12. The developing device according to claim 11,

wherein the first transport member includes a first spindle which extends in the direction of the rotary shaft and a first spiral vane which is formed around the first spindle, and transports the developer in the first direction by the first spiral vane using rotation of the first spindle,

wherein the developing device further comprises a second transport member that is arranged parallel to the first transport member, that includes a second spindle which extends in the direction of the rotary shaft and a second spiral vane which is formed around the second spindle and which is spirally formed on a same cycle as the first spiral vane, and that transports the developer in a second direction opposite to the first direction by the second spiral vane using rotation of the second spindle,

wherein the container includes a partition wall that partitions a first chamber in which the first transport member is arranged and a second chamber in which the second transport member is arranged, and a developer flow path that connects the first chamber and the second chamber which are respectively formed in both end portions of the first transport member and the second transport member, and

wherein the first transport member and the second transport member are arranged in a phase when both the first spiral vane and the second spiral vane simultaneously open a front surface of the flow path on a pushing-back member side within the flow path.

13. The developing device according to claim 10,

wherein the first transport member includes a first spindle which extends in the direction of the rotary shaft and a first spiral vane which is formed around the first spindle, and transports the developer in the first direction by the first spiral vane using rotation of the first spindle,

wherein the developing device further comprises a second transport member that is arranged parallel to the first transport member, that includes a second spindle which extends in the direction of the rotary shaft and a second spiral vane which is formed around the second spindle and which is spirally formed on a same cycle as the first spiral vane, and that transports the developer in a second direction opposite to the first direction by the second spiral vane using rotation of the second spindle,

wherein the container includes a partition wall that partitions a first chamber in which the first transport member is arranged and a second chamber in which the second transport member is arranged, and a developer flow path that connects the first chamber and the second chamber which are respectively formed in both end portions of the first transport member and the second transport member, and

wherein the first transport member and the second transport member are arranged in a phase when both the first spiral vane and the second spiral vane simultaneously open a front surface of the flow path on a pushing-back member side within the flow path.

14. The developing device according to claim 1,

wherein the control wall is formed at a plurality of locations with a space therebetween in the first direction.

15. The developing device according to claim 14,

wherein the first transport member includes a first spindle which extends in the direction of the rotary shaft and a first spiral vane which is formed around the first spindle, and transports the developer in the first direction by the first spiral vane using rotation of the first spindle,

wherein the developing device further comprises a second transport member that is arranged parallel to the first transport member, that includes a second spindle which extends in the direction of the rotary shaft and a second spiral vane which is formed around the second spindle and which is spirally formed on a same cycle as the first spiral vane, and that transports the developer in a second direction opposite to the first direction by the second spiral vane using rotation of the second spindle,

wherein the container includes a partition wall that partitions a first chamber in which the first transport member is arranged and a second chamber in which the second transport member is arranged, and a developer flow path that connects the first chamber and the second chamber which are respectively formed in both end portions of the first transport member and the second transport member, and

wherein the first transport member and the second transport member are arranged in a phase when both the first spiral vane and the second spiral vane simultaneously open a front surface of the flow path on a pushing-back member side within the flow path.

16. The developing device according to claim 1,

wherein the first transport member includes a first spindle which extends in the direction of the rotary shaft and a first spiral vane which is formed around the first spindle, and transports the developer in the first direction by the first spiral vane using rotation of the first spindle,

wherein the developing device further comprises a second transport member that is arranged parallel to the first transport member, that includes a second spindle which extends in the direction of the rotary shaft and a second spiral vane which is formed around the second spindle and which is spirally formed on a same cycle as the first spiral vane, and that transports the developer in a second direction opposite to the first direction by the second spiral vane using rotation of the second spindle,

wherein the container includes a partition wall that partitions a first chamber in which the first transport member is arranged and a second chamber in which the second transport member is arranged, and a developer flow path that connects the first chamber and the second chamber which are respectively formed in both end portions of the first transport member and the second transport member, and

wherein the first transport member and the second transport member are arranged in a phase when both the first spiral vane and the second spiral vane simultaneously open a front surface of the flow path on a pushing-back member side within the flow path.

17. An image forming apparatus comprising:

an image holding member that holds an electrostatic latent image formed thereon, while rotating; and

the developing device according to claim 1.

18. The developing device according to claim 1, wherein the control walls extend in an arc shape.