Developing apparatus having recycling paths for recycling of toner and image forming apparatus including the same

Patent metadata

Field	Value
Publication number	US-9551958-B2
Application number	US-201514694444-A
Country	US
Kind code	B2
Filing date	Apr 23, 2015
Priority date	May 12, 2014
Publication date	Jan 24, 2017
Grant date	Jan 24, 2017

Abstract

A developing apparatus that develops an electrostatic latent image on an image supporting body using developer including toner and carrier includes a circulation path where the developer circulates, a discharge path connected to the circulation path through which some of the developer passes, and a first recycle path connected to the discharge path and allowing some of the developer flowing into the discharge path to return to the circulation path. The discharge path includes a discharge opening for discharging the developer flowing into the discharge path, and a first return opening for connecting to the first recycle path. The first return opening is located on an upper side in a vertical direction with respect to the discharge opening and located on an upstream side in a pass-through direction of the developer flowing into the discharge path.

First claim

What is claimed is:

1. A developing apparatus that develops an electrostatic latent image on an image supporting body, using developer including toner and carrier, the developing apparatus comprising:
a circulation path where the developer circulates;
a discharge path which is connected to the circulation path and through which some of the developer passes; and
a first recycle path connected to the discharge path and allowing some of the developer flowing into the discharge path to return to the circulation path,
wherein:
the discharge path is provided with:
a discharge opening for discharging the developer flowing into the discharge path;
a first return opening for connecting to the first recycle path; and
a supply screw for transporting the developer flowing into the discharge path,

the first return opening is located on an upper side in a vertical direction with respect to the discharge opening and located on an upstream side in a pass-through direction of the developer flowing into the discharge path, and
the developer transported within the discharge path is biased to one side of the discharge path by rotation of the supply screw, and the first return opening is provided in a side wall that is located opposite to the one side of the discharge path in a direction orthogonal to an axis of the supply screw.

2. The developing apparatus according to claim 1 , further comprising:
a second recycle path connected to the discharge path and allowing some of the developer flowing into the discharge path to return to the circulation path,
wherein:
the discharge path is provided with a second return opening for connecting to the second recycle path, and
the second return opening is located on a downstream side in the pass-through direction of the developer flowing into the discharge path, with respect to the discharge opening.

3. The developing apparatus according to claim 2 , wherein the second return opening is located on a lower side in the vertical direction with respect to the discharge opening.

4. The developing apparatus according to claim 1 , wherein a plurality of first return openings are provided in the pass-through direction of the developer flowing into the discharge path.

5. The developing apparatus according to claim 1 , wherein the first return opening is provided over substantially an entire area ranging from a connecting portion between the circulation path and the discharge path to the discharge opening.

6. The developing apparatus according to claim 1 , wherein the first return opening is disposed so as to be adjacent to the discharge opening.

7. The developing apparatus according to claim 1 , wherein
the developing apparatus is included in an image forming apparatus, and
at startup of the image forming apparatus, a supply screw temporarily rotates in an opposite direction to a normal rotation direction of the supply screw.

8. An image forming apparatus comprising the developing apparatus according to claim 1 .

9. A developing apparatus that develops an electrostatic latent image on an image supporting body, using developer including toner and carrier, the developing apparatus comprising:
a circulation path where the developer circulates;
a discharge path which is connected to the circulation path and through which some of the developer passes; and
a first recycle path connected to the discharge path and allowing some of the developer flowing into the discharge path to return to the circulation path,
wherein:
the discharge path is provided with:
a discharge opening for discharging the developer flowing into the discharge path; and
a first return opening for connecting to the first recycle path,

the first return opening is located on an upper side in a vertical direction with respect to the discharge opening and located on an upstream side in a pass-through direction of the developer flowing into the discharge path, and
the first return opening is provided over substantially an entire area ranging from a connecting portion between the circulation path and the discharge path to the discharge opening.

10. The developing apparatus according to claim 9 , further comprising:
a second recycle path connected to the discharge path and allowing some of the developer flowing into the discharge path to return to the circulation path,
wherein:
the discharge path is provided with a second return opening for connecting to the second recycle path, and
the second return opening is located on a downstream side in the pass-through direction of the developer flowing into the discharge path, with respect to the discharge opening.

11. The developing apparatus according to claim 10 , wherein the second return opening is located on a lower side in the vertical direction with respect to the discharge opening.

12. The developing apparatus according to claim 9 , wherein a plurality of first return openings are provided in the pass-through direction of the developer flowing into the discharge path.

13. The developing apparatus according to claim 9 , wherein the first return opening is disposed so as to be adjacent to the discharge opening.

14. The developing apparatus according to claim 9 , wherein
the developing apparatus is included in an image forming apparatus, and
at startup of the image forming apparatus, a supply screw temporarily rotates in an opposite direction to a normal rotation direction of the supply screw.

15. An image forming apparatus comprising the developing apparatus according to claim 9 .

Assignees

• Konica Minolta Inc

Inventors

• Mandai Yuusuke
• Inada Yasuyuki
• Ogawa Shinji
• Kimura Masato
• Mukobayashi Yu

Classifications

• G03G15/0891

  for conveying or circulating developer, e.g. augers · CPC title

• G03G15/0893 Primary

  in a closed loop within the sump of the developing device · CPC title

• G03G2215/0819

  two or more agitators · CPC title

• G03G2215/0607

  two-component · CPC title

• G03G21/10

  Collecting or recycling waste developer · CPC title