# US 2022/0035271 A1 · Developing apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2022/0035271 A1 - Document ID: US20220035271A1 - Status: Published application - Kind: A1 - Application number: 17/376,300 - Filed: 2021-07-15 - Published: 2022-02-03 - Earliest claimed: 2020-07-29 - Assignees: Canon Kabushiki Kaisha - Applicants: Canon Kabushiki Kaisha - Inventors: Masashi Wakisaka - Web page: https://patentgrep.com/patent/US20220035271A1 ## CPC - G03G 15/0891: {for conveying or circulating developer, e.g. augers} - G03G 15/0882: {by a peelable sealing film (resealing used developer units before refilling: G03G15/0894)} - G03G 15/0893: {in a closed loop within the sump of the developing device} - G03G 15/09: using magnetic brush - G03G 21/206: {Conducting air through the machine, e.g. for cooling, filtering, removing gases like ozone} - G03G 2215/0609: magnetic brush - G03G 2215/0687: using a peelable sealing film - G03G 2215/0819: two or more agitators - G03G 2215/0827: Augers - G03G 2215/0838: Circulation of developer in a closed loop within the sump of the developing device - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract A third communicating portion is disposed downstream of the first communicating portion and upstream of the second communicating portion in the first direction. The third communicating portion is disposed above a rotational axis of a first conveyance screw and a rotational axis of a second conveyance screw in a vertical direction. The third communicating portion is configured to allow air inside the developing container to move between the first chamber and the second chamber. An opening portion for discharging the air inside the developing container outside the developing container is disposed above the second chamber in the vertical direction. ## Claims ### Claim 1 A developing apparatus comprising: a rotatable developing member configured to bear and covey 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, and configured to allow air inside the developing container to move between the first chamber and the second chamber, wherein an opening portion for discharging the air inside the developing container outside the developing container is disposed above the second chamber in the vertical direction. ### Claim 2 (depends on 1) The developing apparatus according to claim 1, wherein the developing container further comprises a third chamber disposed above the second chamber in the vertical direction and configured to accommodate initial developer in an unused state of the developing apparatus, and wherein the opening portion is disposed above the third chamber in the vertical direction. ### Claim 3 (depends on 2) The developing apparatus according to claim 2, wherein the developing container comprises a first case portion configured to accommodate the developer and a second case portion fitted to the first case portion and configured to cover a part of an outer circumferential surface of the rotatable developing member, the first conveyance screw and the second conveyance screw being disposed in the first case portion, and wherein the third chamber is disposed in the second case portion. ### Claim 4 (depends on 2) The developing apparatus according to claim 2, further comprising an initial developer sealing sheet stuck to the developing container in the unused state of the developing apparatus and configured to seal the initial developer in the third chamber, wherein the opening portion is able to discharge the air inside the developing container outside the developing container with the initial developer sealing sheet stuck to the developing container. ### Claim 5 (depends on 4) The developing apparatus according to claim 4, wherein an uppermost edge of the third communicating portion is disposed below a part, on a side of the partition wall, of a sticking portion where the initial developer sealing sheet is stuck to the developing container, in the vertical direction. ### Claim 6 (depends on 1) The developing apparatus according to claim 1, further comprising a magnet non-rotatably fixedly disposed inside the rotatable developing member, the magnet comprising a first magnetic pole and a second magnetic pole, the second magnetic pole being disposed downstream of the first magnetic pole in a rotational direction of the rotatable developing member, the first magnetic pole and the second magnetic pole being disposed adjoiningly to each other and having a same polarity, wherein an uppermost edge of the third communicating portion is disposed below a position where a magnetic flux density of the first magnetic pole in a normal direction of the rotatable developing member becomes maximum, in the vertical direction. ### Claim 7 (depends on 1) The developing apparatus according to claim 1, wherein the third communicating portion is formed across an area equal to or more than 90% of an area between a downstream end of the first communicating portion and an upstream end of the second communicating portion in the first direction. ### Claim 8 (depends on 1) The developing apparatus according to claim 1, wherein a filter configured to catch the toner is disposed in the opening portion. ### Claim 9 (depends on 8) The developing apparatus according to claim 8, wherein a filter cover configured to cover the filter is disposed above the filter in the vertical direction so as to overlap with the filter.