# US 10,481,526 B2 · Image-forming apparatus and image-forming method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,481,526 B2 - Document ID: US10481526B2 - Status: Granted - Kind: B2 - Application number: 15/945,382 - Filed: 2018-04-04 - Published: 2019-03-28 - Granted: 2019-11-19 - Earliest claimed: 2017-09-27 - Assignees: Fuji Xerox Co., Ltd. - Applicants: Fuji Xerox Co., Ltd. - Inventors: Yoshiteru Yamada - Web page: https://patentgrep.com/patent/US10481526B2 ## CPC - G03G 15/105: {Detection or control means for the toner concentration} - G03G 15/0877: {Arrangements for metering and dispensing developer from a developer cartridge into the development unit} - G03G 15/75: {Details relating to xerographic drum, band or plate, e.g. replacing, testing (electrographic recording members per se G03G5/00)} - G03G 15/0849: {Detection or control means for the developer concentration} - G03G 15/101: {for wetting the recording material} - G03G 15/5033: {by measuring the photoconductor characteristics, e.g. temperature, or the characteristics of an image on the photoconductor} - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract An image-forming apparatus includes an electrophotographic photosensitive member including a conductive base and a single-layer photosensitive layer disposed on the conductive base, the single-layer photosensitive layer including a binder resin, a charge-generating material, a hole-transporting material, and an electron-transporting material; and a developing unit including a developing roller that develops an electrostatic latent image formed on a surface of the electrophotographic photosensitive member with a developer including a toner in order to form a toner image, the developing roller being arranged to come into contact with the photosensitive layer. The ratio R/P of the content R [mass %] of the binder resin in the photosensitive layer to the pressing force P [N/mm] at which the developing roller is pressed against the photosensitive layer is about 11.5 or more and about 19.6 or less. ## Claims ### Claim 1 An image-forming apparatus comprising: an electrophotographic photosensitive member including a conductive base and a single-layer photosensitive layer disposed on the conductive base, the single-layer photosensitive layer including a binder resin, a charge-generating material, a hole-transporting material, and an electron-transporting material; and a developing unit including a developing roller that develops an electrostatic latent image formed on a surface of the electrophotographic photosensitive member with a developer including a toner in order to form a toner image, the developing roller being arranged to come into contact with the photosensitive layer, wherein the ratio R/P of the content R [mass %] of the binder resin in the photosensitive layer to the pressing force P [N/mm] at which the developing roller is pressed against the photosensitive layer is 11.5 or more and 19.6 or less, and the content R of the binder resin is 45% by mass or more. ### Claim 2 (depends on 1) The image-forming apparatus according to claim 1, wherein the content R of the binder resin is 45% by mass or more and 70% by mass or less. ### Claim 3 (depends on 1) The image-forming apparatus according to claim 1, wherein the content R of the binder resin is 45% by mass or more and 60% by mass or less. ### Claim 4 (depends on 1) The image-forming apparatus according to claim 1, wherein the pressing force P at which the developing roller is pressed against the photosensitive layer is 2.5 N/mm or more and 6.5 N/mm or less. ### Claim 5 (depends on 4) The image-forming apparatus according to claim 4, wherein the pressing force P at which the developing roller is pressed against the photosensitive layer is 3.0 N/mm or more and 5.5 N/mm or less. ### Claim 6 (depends on 1) The image-forming apparatus according to claim 1, wherein the binder resin is at least one resin selected from the group consisting of a polycarbonate resin, a polyester resin, and a polyarylate resin. ### Claim 7 (depends on 6) The image-forming apparatus according to claim 6, wherein the binder resin is a polycarbonate resin. ### Claim 8 (depends on 1) The image-forming apparatus according to claim 1, further comprising: a charging unit that charges the surface of the electrophotographic photosensitive member; an electrostatic latent image-forming unit that forms an electrostatic latent image on the charged surface of the electrophotographic photosensitive member; and a transfer unit that transfers the toner image onto a surface of a recording medium. ### Claim 9 (depends on 1) The image-forming apparatus according to claim 1, wherein the image-forming apparatus does not include a cleaning unit, other than the developing roller, which cleans the surface of the photosensitive member before the photosensitive member is charged. ### Claim 10 An image-forming method comprising: using an image-forming apparatus including an electrophotographic photosensitive member including a conductive base and a single-layer photosensitive layer disposed on the conductive base, the single-layer photosensitive layer including a binder resin, a charge-generating material, a hole-transporting material, and an electron-transporting material, and a developing unit including a developing roller that develops an electrostatic latent image formed on a surface of the electrophotographic photosensitive member with a developer including a toner in order to form a toner image, the developing roller being arranged to come into contact with the photosensitive layer, developing an electrostatic latent image formed on the surface of the electrophotographic photosensitive member with a developer including a toner in order to form a toner image, wherein the ratio R/P of the content R [mass %] of the binder resin in the photosensitive layer to the pressing force P [N/mm] at which the developing roller is pressed against the photosensitive layer is 11.5 or more and 19.6 or less, and the content R of the binder resin is 45% by mass or more. ### Claim 11 (depends on 10) The image-forming method according to claim 10, the method further comprising: charging the surface of the electrophotographic photosensitive member; forming an electrostatic latent image on the charged surface of the electrophotographic photosensitive member; and transferring the toner image onto a surface of a recording medium. ### Claim 12 (depends on 10) The image-forming method according to claim 10, wherein the image-forming method does not include a cleaning step in which a part of the developer which remains on the photosensitive member is removed with a cleaning blade. ### Claim 13 (depends on 10) The image-forming method according to claim 10, wherein the step of developing an electrostatic latent image formed on the surface of the electrophotographic photosensitive member includes performing cleaning of the photosensitive member.