US 12,066,771 B2
Developing apparatus having air discharge
Masashi Wakisaka, Saitama (JP)
Assigned to CANON KABUSHIKI KAISHA, Tokyo (JP)
Filed by CANON KABUSHIKI KAISHA, Tokyo (JP)
Filed on Jul. 15, 2021, as Appl. No. 17/376,300.
Claims priority of application No. 2020-128591 (JP), filed on Jul. 29, 2020; and application No. 2021-107354 (JP), filed on Jun. 29, 2021.
Prior Publication US 2022/0035271 A1, Feb. 3, 2022
Int. Cl. G03G 15/08 (2006.01); G03G 15/09 (2006.01); G03G 21/20 (2006.01)
CPC G03G 15/0891 (2013.01) [G03G 15/0882 (2013.01); G03G 15/0893 (2013.01); G03G 15/09 (2013.01); G03G 21/206 (2013.01); G03G 2215/0609 (2013.01); G03G 2215/0687 (2013.01); G03G 2215/0819 (2013.01); G03G 2215/0827 (2013.01); G03G 2215/0838 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A developing apparatus comprising:
a rotatable developing member configured to bear and convey developer containing a toner and a carrier so as to develop an electrostatic latent image formed on an image bearing member;
a developing container configured to accommodate the developer, the developing container comprising a first chamber supplying the developer to the rotatable developing member, a second chamber, and a partition wall separating the first chamber and the second chamber, the developer circulating between the first chamber and the second chamber;
a first communicating portion configured to allow the developer to move from the second chamber to the first chamber;
a second communicating portion configured to allow the developer to move from the first chamber to the second chamber;
a first conveyance screw disposed in the first chamber, and configured to convey the developer in a first direction from the first communicating portion toward the second communicating portion;
a second conveyance screw disposed in the second chamber, and configured to convey the developer in a second direction from the second communicating portion toward the first communicating portion; and
a third communicating portion disposed downstream of the first communicating portion and upstream of the second communicating portion in the first direction, disposed above a rotational axis of the first conveyance screw and a rotational axis of the second conveyance screw in a vertical direction,
wherein the developing container further comprises a third chamber disposed above the second chamber in the vertical direction,
wherein an opening portion for discharging air inside the developing container to outside of the developing container is provided in the third chamber, the opening portion being disposed above the third communication portion,
wherein in a sealing state where a sealing member is stuck to the developing container, the second chamber is not in communication with the third chamber and initial developer is sealed in the third chamber by the sealing member stuck to the developing container, the air inside the developing container communicates between the first chamber and the second chamber through the third communicating portion, and the air inside the developing container does not communicate between the second chamber and the third chamber, and
wherein in an unsealed state where the sealing member is not stuck to the developing container, the second chamber is in communication with the third chamber and the initial developer is not sealed in the third chamber, the air inside the first chamber is allowed to move into the second chamber through the third communication portion, the air inside the second chamber is allowed to move into the third chamber, and the air inside the third chamber is able to be discharged to outside of the developing container through the opening portion.