# US 12,001,151 B2 · Developing device including regulation member with different diameters of central portion and both end portions > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,001,151 B2 - Document ID: US12001151B2 - Status: Granted - Kind: B2 - Application number: 18/039,926 - Filed: 2021-03-23 - Published: 2024-01-04 - Granted: 2024-06-04 - Earliest claimed: 2020-12-21 - Assignees: Hewlett-Packard Development Company, L.P. - Applicants: Hewlett-Packard Development Company, L.P. - Inventors: Seongwoong Yang; Youngchae Kim; Jinhong Kim; Sunghoon Oh - Web page: https://patentgrep.com/patent/US12001151B2 ## CPC - G03G 15/0812: {characterised by the developer regulating means, e.g. structure of doctor blade} - G03G 15/06: for developing - G03G 15/0808: {characterised by the developer supplying means, e.g. structure of developer supply roller} - G03G 15/0817: {characterised by the lateral sealing at both sides of the donor member with respect to the developer carrying direction} - G03G 15/0881: {Sealing of developer cartridges} - 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: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract A developing device may include a housing to accommodate a developing agent, a developing roller to convey the developing agent adhered to an outer periphery of the developing roller to an outside of the housing, a regulation member positioned apart from the developing roller and having a circular cross-sectional shape to regulate a thickness of the developing agent adhered to the developing roller, and a sealing member between the regulation member and the housing to prevent leakage of the developing agent. A diameter of a central portion of the regulation member may be different from diameters of both end portions of the regulation member. ## Claims ### Claim 1 A developing device comprising: a housing to accommodate a developing agent; a developing roller to convey the developing agent adhered to an outer periphery of the developing roller to an outside of the housing; and a regulation member positioned apart from the developing roller and having a circular cross-sectional shape to regulate a thickness of the developing agent adhered to the developing roller, wherein a central portion of the regulation member has a first diameter different from a diameter of each of end portions of the regulation member. ### Claim 2 (depends on 1) The developing device of claim 1, wherein a difference between the first diameter of the central portion of the regulation member and the diameter of each of the end portions of the regulation member is 0.2 millimeters or less. ### Claim 3 (depends on 1) The developing device of claim 1, further comprising a sealing member to prevent leakage of the developing agent through a gap between the regulation member and the housing by blocking the gap. ### Claim 4 (depends on 3) The developing device of claim 3, wherein a sealing member presses the regulation member in a direction toward the developing roller, and the first diameter of the central portion is less than the diameter of each of the end portions. ### Claim 5 (depends on 4) The developing device of claim 4, wherein the regulation member decreases in diameter along a longitudinal axis of the regulation member from both of the end portions to the central portion. ### Claim 6 (depends on 4) The developing device of claim 4, wherein the regulation member decreases in diameter in stages along a longitudinal axis of the regulation member from both of the end portions to the central portion. ### Claim 7 (depends on 3) The developing device of claim 3, wherein a sealing member presses the regulation member in a direction away from the developing roller, and the first diameter of the central portion is greater than the diameter of each of the end portions. ### Claim 8 (depends on 7) The developing device of claim 7, wherein the regulation member increases in diameter along a longitudinal axis of the regulation member from both of the end portions to the central portion. ### Claim 9 (depends on 7) The developing device of claim 7, wherein the regulation member increases in diameter along a longitudinal axis of the regulation member in stages from both of the end portions to the central portion. ### Claim 10 (depends on 1) The developing device of claim 1, wherein the housing has an opening portion, and the developing roller comprises a developing sleeve and a magnet, wherein the developing sleeve is rotatably supported by the housing and is partially exposed to the outside of the housing through the opening portion, and the magnet is arranged inside the developing sleeve and provides a magnetic force to cause adherence of the developing agent to an outer periphery of the developing sleeve. ### Claim 11 (depends on 10) The developing device of claim 10, wherein the regulation member is arranged at an upstream side end portion of the opening portion based on a rotation direction of the developing sleeve. ### Claim 12 An image forming apparatus comprising: a photoconductive drum; and a developing device to supply a developing agent to an electrostatic latent image formed on the photoconductive drum to develop the electrostatic latent image, wherein the developing device comprises: a housing to accommodate the developing agent; a developing roller to convey the developing agent adhered to an outer periphery of the developing roller to an outside of the housing; and a regulation member positioned apart from the developing roller and having a circular cross-sectional shape, wherein a first diameter of a central portion of the regulation member is different from diameters of both of end portions of the regulation member, the regulation member to regulate a thickness of the developing agent adhered to the developing roller. ### Claim 13 (depends on 12) The image forming apparatus of claim 12, wherein a difference between the first diameter of the central portion and the diameter of each of the end portions of the regulation member is 0.2 millimeters or less. ### Claim 14 (depends on 12) The image forming apparatus of claim 12, further comprising a sealing member to prevent leakage of the developing agent through a gap between the regulation member and the housing by elastically blocking the gap. ### Claim 15 (depends on 14) The image forming apparatus of claim 14, wherein the sealing member presses the regulation member in a direction toward the developing roller, and the first diameter of the central portion is less than the diameter of each of the end portions. ### Claim 16 (depends on 14) The image forming apparatus of claim 14, wherein the sealing member presses the regulation member in a direction away from the developing roller, and the first diameter of the central portion is greater than the diameter of each of the end portions.