# US 2024/0201624 A1 · Fixing device including elastic plate for nipping endless belt in cooperation with heating roller, and holder having supporting surfaces for supporting elastic plate > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2024/0201624 A1 - Document ID: US20240201624A1 - Status: Published application - Kind: A1 - Application number: 18/518,149 - Filed: 2023-11-22 - Published: 2024-06-20 - Earliest claimed: 2022-12-14 - Assignees: Brother Kogyo Kabushiki Kaisha - Applicants: Brother Kogyo Kabushiki Kaisha - Inventors: Mingguang ZHANG; Tokifumi TANAKA - Web page: https://patentgrep.com/patent/US20240201624A1 ## CPC - G03G 15/2064: {combined with pressure} - G03G 15/2017: {Structural details of the fixing unit in general, e.g. cooling means, heat shielding means (G03G15/2053 takes precedence)} - G03G 15/2028: {with means for handling the copy material in the fixing nip, e.g. introduction guides, stripping means} - G03G 15/2053: {Structural details of heat elements, e.g. structure of roller or belt, eddy current, induction heating} - G03G 15/206: {Structural details or chemical composition of the pressure elements and layers thereof} - G03G 2215/20: Details of the fixing device or porcess - G03G 2215/2003: Structural features of the fixing device - G03G 2215/2009: Pressure belt - G03G 2215/2032: the belt further entrained around additional rotating belt support members - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract A fixing device includes a heating roller and a pressure unit configured to nip a sheet therebetween to thermally fix a toner image onto the sheet. The pressure unit includes: an endless belt; an elastic plate; and a holder having an upstream supporting surface and a downstream supporting surface. The elastic plate has: a nip-forming surface having at least a portion for nipping the endless belt in cooperation with the heating roller to form a nipping region between the nip-forming surface and the heating roller; an upstream supported surface in contact with and supported by the upstream supporting surface; a downstream supported surface in contact with and supported by the downstream supporting surface; an upstream connecting surface connecting the nip-forming surface and the upstream supported surface to each other; and a downstream connecting surface connecting the nip-forming surface and the downstream supported surface to each other. ## Claims ### Claim 1 A fixing device comprising: a heating roller rotatable about a rotational axis extending in a rotational axis direction; and a pressure unit configured to nip a sheet and convey the sheet in a conveying direction in cooperation with the heating roller and to thermally fix a toner image onto the sheet, the pressure unit comprising: an endless belt circularly movable while in contact with the heating roller; an elastic plate extending in the rotational axis direction, the elastic plate making contact with an inner peripheral surface of the endless belt to nip the endless belt in cooperation with the heating roller; and a holder extending in the rotational axis direction, the holder being positioned within a space encircled by the endless belt and supporting the elastic plate, the holder having: an upstream supporting surface facing the heating roller; and a downstream supporting surface positioned further downstream than the upstream supporting surface in the conveying direction, the downstream supporting surface facing the heating roller, wherein the elastic plate has: a nip-forming surface having at least a portion for nipping the endless belt in cooperation with the heating roller to form a nipping region between the nip-forming surface and the heating roller; an upstream supported surface in contact with and supported by the upstream supporting surface; a downstream supported surface in contact with and supported by the downstream supporting surface; an upstream connecting surface connecting the nip-forming surface and the upstream supported surface to each other, the upstream connecting surface being curved when viewed in the rotational axis direction; and a downstream connecting surface connecting the nip-forming surface and the downstream supported surface to each other, the downstream connecting surface being curved when viewed in the rotational axis direction. ### Claim 2 (depends on 1) The fixing device according to claim 1, wherein the upstream connecting surface is positioned further upstream than the nip-forming surface in the conveying direction, and wherein the upstream connecting surface is curved so as to expand upstream in the conveying direction. ### Claim 3 (depends on 1) The fixing device according to claim 1, wherein the downstream connecting surface is positioned further downstream than the nip-forming surface in the conveying direction, and wherein the downstream connecting surface is curved so as to expand downstream in the conveying direction. ### Claim 4 (depends on 3) The fixing device according to claim 3, wherein the pressure unit further comprises: a restricting surface positioned further downstream than the downstream supporting surface in the conveying direction and positioned closer to the heating roller than the downstream supporting surface is to the heating roller, the restricting surface facing upstream in the conveying direction, and wherein the downstream connecting surface is in contact with the restricting surface. ### Claim 5 (depends on 1) The fixing device according to claim 1, wherein the downstream supported surface is in contact with the downstream supporting surface while the downstream supported surface is not movable in the conveying direction. ### Claim 6 (depends on 1) The fixing device according to claim 1, wherein the upstream supported surface is in contact with the upstream supporting surface while the upstream supported surface is movable upstream in the conveying direction. ### Claim 7 (depends on 4) The fixing device according to claim 4, wherein the holder has the restricting surface. ### Claim 8 (depends on 4) The fixing device according to claim 4, wherein the downstream connecting surface has a portion that makes contact with the restricting surface, and wherein, in a state where the elastic plate is not elastically deformed, the portion is positioned closer to the downstream supported surface than to the nip-forming surface in a direction in which the heating roller and the pressure unit are aligned. ### Claim 9 (depends on 1) The fixing device according to claim 1, wherein, when viewed in the rotational axis direction in a state where the elastic plate is not elastically deformed, the nip-forming surface is formed in one of a linear shape, and a curved shape in which a middle portion in the conveying direction of the nip-forming surface is separated from the heating roller. ### Claim 10 (depends on 9) The fixing device according to claim 9, further comprising an urging mechanism supporting the pressure unit so that the heating roller and the pressure unit can approach each other and separate away from each other, the urging mechanism can exert a first urging force for pressing the pressure unit against the heating roller, wherein, when the elastic plate is elastically deformed by the first urging force, a downstream end in the conveying direction of the nip-forming surface constitutes the nipping region. ### Claim 11 (depends on 10) The fixing device according to claim 10, wherein the urging mechanism is configured to exert selected one of the first urging force, and a second urging force for pressing the pressure unit against the heating roller, the second urging force being smaller than the first urging force, and wherein, when the elastic plate is elastically deformed by the second urging force, the downstream end in the conveying direction of the nip-forming surface does not constitute the nipping region. ### Claim 12 (depends on 1) The fixing device according to claim 1, wherein the elastic plate is made of stainless steel.