# US 11,487,224 B2 · Developing device with elastic film to block air input > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,487,224 B2 - Document ID: US11487224B2 - Status: Granted - Kind: B2 - Application number: 17/309,576 - Filed: 2020-02-18 - Published: 2022-02-03 - Granted: 2022-11-01 - Earliest claimed: 2019-10-01 - Assignees: Hewlett-Packard Development Company, L.P. - Applicants: Hewlett-Packard Development Company, L.P. - Inventors: Mitsuru Oikawa; Ohdug Kwon; Yoshihiko Ichikawa - Web page: https://patentgrep.com/patent/US11487224B2 ## CPC - G03G 15/09: using magnetic brush - G03G 15/0921: {Details concerning the magnetic brush roller structure, e.g. magnet configuration} - G03G 15/0812: {characterised by the developer regulating means, e.g. structure of doctor blade} - G03G 15/0815: {characterised by the developer handling means after the developing zone and before the supply, e.g. developer recovering roller} - G03G 15/0891: {for conveying or circulating developer, e.g. augers} - G03G 15/0898: {for preventing toner scattering during operation, e.g. seals (sealing the donor member G03G15/0817; sealing the magnetic brush G03G15/0942)} - G03G 15/0942: {with means for preventing toner scattering from the magnetic brush, e.g. magnetic seals} - G03G 15/0893: {in a closed loop within the sump of the developing device} - G03G 2215/0609: magnetic brush - G03G 2221/1648: using seals, e.g. to prevent scattering of toner - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract An example developing device includes a housing to contain a developer and having an opening, a developing sleeve provided in the housing and partially exposed to the outside of the housing through the opening, a magnetic member including a plurality of magnetic poles and located inside the developing sleeve, and an elastic member blocking an inflow of air through a space between a downstream edge of the opening in a rotation direction of the developing sleeve and an outer circumferential surface of the developing sleeve. The elastic member includes a fixed portion fixed to the housing at a position adjacent to the downstream edge of the opening and an extension portion extending from the fixed portion in a bent form in the rotation direction of the developing sleeve to be elastically in contact with the surface of the developing sleeve. ## Claims ### Claim 1 A developing device comprising: a housing to contain a developer and having an opening; a developing sleeve provided in the housing and partially exposed to an outside of the housing through the opening; a magnetic member comprising a plurality of magnetic poles and located inside the developing sleeve; an elastic member blocking an inflow of air through a space between a downstream edge of the opening in a rotation direction of the developing sleeve and an outer circumferential surface of the developing sleeve, wherein the elastic member comprises: a fixed portion fixed to the housing at a position adjacent to the downstream edge of the opening; and an extension portion extending from the fixed portion and bent from the fixed portion in a forward direction with respect to the rotation direction of the developing sleeve to be elastically in contact with the outer circumferential surface of the developing sleeve; and a regulating member located at an upstream side of the opening in the rotation direction of the developing sleeve to regulate a thickness of the developer supplied to the opening, wherein the regulating member is spaced apart from the outer circumferential surface of the developing sleeve by a regulation gap, wherein the regulation gap is equal to or greater than a minimum gap between the housing and the developing sleeve at a downstream side of the opening in the rotation direction of the developing sleeve. ### Claim 2 (depends on 1) The developing device of claim 1, wherein an angle between a first line tangential to the outer circumferential surface of the developing sleeve at a contact portion where the extension portion contacts the developing sleeve and a second line extending from the fixed portion toward the developing sleeve is 90 degrees or more, the second line being along a length of the fixed portion, and the angle facing away from the developing sleeve and away from the extension portion. ### Claim 3 (depends on 1) The developing device of claim 1, wherein a magnetic flux density formed by the plurality of magnetic poles in a normal direction is 30 millitesla or less at a contact portion between the extension portion and the developing sleeve. ### Claim 4 (depends on 3) The developing device of claim 3, wherein the plurality of magnetic poles comprise a developing pole located to correspond to the opening and a conveying pole located at the downstream side of the opening, and wherein the extension portion is in contact with the developing sleeve between the downstream edge of the opening and the conveying pole. ### Claim 5 (depends on 4) The developing device of claim 4, wherein the extension portion is in contact with the developing sleeve within ±10 degrees of a position where an absolute value of the magnetic flux density in the normal direction is minimized between the developing pole and the conveying pole. ### Claim 6 (depends on 1) The developing device of claim 1, wherein the extension portion bending away from the fixed portion has an arc shape. ### Claim 7 (depends on 6) The developing device of claim 6, wherein the fixed portion is linear. ### Claim 8 (depends on 1) The developing device of claim 1, wherein the elastic member comprises a polyethylene film, and wherein a thickness of the polyethylene film is in a range of 0.01 millimeters (mm) to 0.1 mm. ### Claim 9 (depends on 1) The developing device of claim 1, further comprising a developer outlet to discharge a surplus of the developer contained in the housing. ### Claim 10 A developing device comprising: a housing to contain a developer, the housing comprising an opening and a developer outlet to discharge a surplus of the developer; a developing sleeve provided in the housing and comprising a development region partially exposed to an outside of the housing through the opening; a magnetic member located inside the developing sleeve to generate a magnetic force and comprising a developing pole located to correspond to the opening and a conveying pole located at a downstream side of the opening in a rotation direction of the developing sleeve, the conveying pole having an opposite magnetic polarity to that of the developing pole; an elastic member comprising a fixed portion fixed to the housing at a position adjacent to a downstream edge of the opening, and an extension portion elastically in contact with the developing sleeve upstream of the conveying pole in the rotation direction of the developing sleeve, wherein the extension portion extends from the fixed portion and is bent from the fixed portion in a forward direction with respect to the rotation direction of the developing sleeve to be elastically in contact with an outer circumferential surface of the developing sleeve; and a regulating member located at an upstream side of the opening in the rotation direction of the developing sleeve to regulate a thickness of the developer supplied to the opening, wherein the regulating member is spaced apart from the outer circumferential surface of the developing sleeve by a regulation gap, wherein the regulation gap is equal to or greater than a minimum gap between the housing and the developing sleeve at the downstream side of the opening. ### Claim 11 (depends on 10) The developing device of claim 10, wherein a magnetic flux density in a normal direction provided by the magnetic member is 30 millitesla or less at a contact portion between the extension portion and the developing sleeve. ### Claim 12 (depends on 11) The developing device of claim 11, wherein the extension portion is in contact with the developing sleeve within ±10 degrees of a position where an absolute value of the magnetic flux density in the normal direction is minimized between the developing pole and the conveying pole. ### Claim 13 (depends on 10) The developing device of claim 10, wherein an angle between a first line tangential to the outer circumferential surface of the developing sleeve at a contact portion where the extension portion contacts the developing sleeve and a second line extending from the fixed portion toward the developing sleeve is 90 degrees or more, the second line being along a length of the fixed portion, and the angle facing away from the developing sleeve and away from the extension portion. ### Claim 14 (depends on 10) The developing device of claim 10, wherein the elastic member comprises a polyethylene film, and wherein a thickness of the polyethylene film is in a range of 0.01 mm to 0.1 mm. ### Claim 15 (depends on 10) The developing device of claim 10, wherein the extension portion bending away from the fixed portion has an arc shape, and the fixed portion is linear.