# US 9,753,391 B1 · Charging member, process cartridge, and image forming apparatus for reducing production of micro-chromatic line and white spot > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,753,391 B1 - Document ID: US9753391B1 - Status: Granted - Kind: B1 - Application number: 15/217,265 - Filed: 2016-07-22 - Published: 2017-09-28 - Granted: 2017-09-05 - Earliest claimed: 2016-03-22 - Assignees: Fuji Xerox Co., Ltd. - Applicants: Fuji Xerox Co., Ltd. - Inventors: Kosuke Narita; Hiroyuki Miura; Yoshiyuki Hayashi - Web page: https://patentgrep.com/patent/US9753391B1 ## CPC - G03G 15/0233: {Structure, details of the charging member, e.g. chemical composition, surface properties} - G03G 21/18: using a processing cartridge {, whereby the process cartridge comprises at least two image processing means in a single unit} - G03G 21/1814: {Details of parts of process cartridge, e.g. for charging, transfer, cleaning, developing (G03G21/1835 takes precedence)} - G03G 2215/021: by contact, friction or induction - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract A charging member includes a support member, a conductive elastic layer disposed on the support member, and a front surface layer disposed on the conductive elastic layer. Irregularities with a cycle of shorter than 0.1 mm and irregularities with a cycle of 0.1 mm or longer are distributed on an entirety of an outer circumferential surface of the charging member, and satisfy the following conditions of (1) and (2): (1) the irregularities with the cycle of shorter than 0.1 mm have an average height of from 8 μm to 11 μm; and (2) the irregularities with the cycle of 0.1 mm or longer have an average height of from 2 μm to 5 μm. A half-value width of the maximum frequency value of height distribution on the outer circumferential surface is from 1 μm to 3 μm. ## Claims ### Claim 1 A charging member comprising: a support member; a conductive elastic layer disposed on the support member; and a surface layer disposed on the conductive elastic layer, wherein first irregularities of a first type with a cycle of shorter than 0.1 mm and second irregularities of a second type with a cycle of 0.1 mm or longer are distributed on an entirety of an outer circumferential surface of the charging member, and satisfy the following conditions of (1) and (2): (1) the first irregularities with the cycle of shorter than 0.1 mm have an average height of from 8 μm to 11 μm; and (2) the second irregularities with the cycle of 0.1 mm or longer have an average height of from 2 μm to 5 μm, and wherein a half-value width of the maximum frequency value of height distribution on the outer circumferential surface is from 1 μm to 3 μm. ### Claim 2 (depends on 1) The charging member according to claim 1, wherein the first irregularities with the cycle of shorter than 0.1 mm have an average height of from 9.0 μm to 10.8 μm. ### Claim 3 (depends on 1) The charging member according to claim 1, wherein the first irregularities with the cycle of shorter than 0.1 mm have an average height of from 9.5 μm to 10.5 μm. ### Claim 4 (depends on 1) The charging member according to claim 1, wherein the second irregularities with the cycle of 0.1 mm or longer have an average height of from 2.5 μm to 4.5 μm. ### Claim 5 (depends on 1) The charging member according to claim 1, wherein the second irregularities with the cycle of 0.1 mm or longer have an average height of from 3.0 μm to 4.0 μm. ### Claim 6 (depends on 1) The charging member according to claim 1, wherein a mean cycle of the first irregularities with the cycle of shorter than 0.1 mm is 5 μm or longer. ### Claim 7 (depends on 1) The charging member according to claim 1, wherein a mean cycle of the first irregularities with the cycle of shorter than 0.1 mm is 50 μm or shorter. ### Claim 8 (depends on 1) The charging member according to claim 1, wherein a mean cycle of the second irregularities with the cycle of 0.1 mm or longer is 0.20 mm or longer. ### Claim 9 (depends on 1) The charging member according to claim 1, wherein a mean cycle of the second irregularities with the cycle of 0.1 mm or longer is 0.45 mm or shorter. ### Claim 10 (depends on 1) The charging member according to claim 1, wherein the surface layer contains an electrically conductive agent. ### Claim 11 (depends on 10) The charging member according to claim 10, wherein the electrically conductive agent is a metal oxide. ### Claim 12 (depends on 1) A process cartridge that is attachable to and detachable from an image forming apparatus, the process cartridge comprising: an electrophotographic photoreceptor; and a charging device that includes the charging member according to claim 1, wherein the charging device is configured to apply, to the charging member, only a DC voltage or a voltage obtained by superimposing an AC voltage to a DC voltage, and wherein the charging device is configured to charge a surface of the electrophotographic photoreceptor by a contact charging method. ### Claim 13 (depends on 1) An image forming apparatus comprising: an electrophotographic photoreceptor; a charging device that includes the charging member according to claim 1, wherein the charging device is configured to apply, to the charging member, only a DC voltage or a voltage obtained by superimposing an AC voltage to a DC voltage, and wherein the charging device is configured to charge a surface of the electrophotographic photoreceptor by a contact charging method; a latent image forming device configured to form a latent image on the surface of the charged electrophotographic photoreceptor; a developing device configured to develop the latent image formed on the surface of the electrophotographic photoreceptor, using developer containing toner, and configured to form a toner image on the surface of the electrophotographic photoreceptor; and a transfer device configured to transfer the toner image formed on the surface of the electrophotographic photoreceptor to a recording medium. ### Claim 14 (depends on 1) The charging member according to claim 1, wherein the first irregularities of the first type comprise a roughness component of the surface layer, and wherein the second irregularities of the second type comprise a waviness component of the surface layer.