US 12,405,554 B2
Developing device and image forming apparatus
Tamotsu Shimizu, Osaka (JP); Kenichi Tamaki, Osaka (JP); Hiroshi Yamazaki, Osaka (JP); Junichi Nakagawa, Osaka (JP); and Takuji Watanabe, Osaka (JP)
Assigned to KYOCERA Document Solutions Inc., Osaka (JP)
Filed by KYOCERA Document Solutions Inc., Osaka (JP)
Filed on Nov. 22, 2023, as Appl. No. 18/517,655.
Claims priority of application No. 2022-191115 (JP), filed on Nov. 30, 2022.
Prior Publication US 2024/0176262 A1, May 30, 2024
Int. Cl. G03G 15/08 (2006.01)
CPC G03G 15/0898 (2013.01) [G03G 15/0891 (2013.01); G03G 2215/085 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A developing device comprising:
a development container including a first conveyance chamber and a second conveyance chamber placed in parallel juxtaposition and a first communicating portion and a second communicating portion through which the first and second conveyance chambers communicate with each other at their longitudinal both end portions, the development container containing a toner-containing developer to be fed to an image carrier;
a first conveyance member and a second conveyance member which are rotatably supported by the first conveyance chamber and the second conveyance chamber, respectively, and which convey and circulate the developer, while stirring the developer, in mutually opposite directions of the longitudinal direction;
a developer carrier which is rotatably supported by the development container in opposition to the image carrier, and which feeds the toner contained in the second conveyance chamber to the image carrier; and
a toner trapping mechanism for trapping the toner contained in the second conveyance chamber, wherein
the toner trapping mechanism includes:
a duct which is connected to the second conveyance chamber and which allows air present in the second conveyance chamber to flow therethrough;
an air inlet port which is opened at a connecting portion between the duct and the second conveyance chamber and which allows air present in the second conveyance chamber to flow into the duct;
a trapping filter which traps the toner contained in air flowing through the duct; and
a fan which allows air present in the second conveyance chamber to be sucked into the duct and let to flow outside,
the developer is a two-component developer containing magnetic carrier and the toner,
the development container has:
an air vent disposed at a location different from the first and second communicating portions, the air vent being opened in a circumferential wall part of the first conveyance chamber from inside to outside the air vent being communicated with outside of the development container; and
a developer discharge port which is formed at a downstream-side end portion of the second conveyance chamber as viewed in a developer conveyance direction of the second conveyance chamber and which allows excess portion of the developer present within the development container to be discharged outside, and
the air vent is placed on a downstream-side end portion of the first conveyance chamber in its developer conveyance direction, the downstream-side end portion being opposite to a side on which the developer discharge port is placed.