# US 9,753,416 B2 · Fixing device including a guide having a roughened face and image forming apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,753,416 B2 - Document ID: US9753416B2 - Status: Granted - Kind: B2 - Application number: 15/149,558 - Filed: 2016-05-09 - Published: 2016-12-01 - Granted: 2017-09-05 - Earliest claimed: 2015-05-25 - Assignees: Ricoh Company, Ltd. - Applicants: Jun Okamoto - Inventors: Jun Okamoto - Web page: https://patentgrep.com/patent/US9753416B2 ## CPC - G03G 15/2028: {with means for handling the copy material in the fixing nip, e.g. introduction guides, stripping means} - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract A fixing device includes a fixing rotator rotatable in a predetermined direction of rotation and a pressure rotator to press against the fixing rotator to form a fixing nip between the fixing rotator and the pressure rotator, through which a recording medium bearing a toner image is conveyed. A guide is disposed upstream from the fixing nip in a recording medium conveyance direction to guide the recording medium to the fixing nip. The guide includes a projection extending in the recording medium conveyance direction, a contact face to come into contact with the recording medium, and a roughened face disposed on at least a part of the contact face. ## Claims ### Claim 1 A fixing device comprising: a fixing rotator rotatable in a predetermined direction of rotation; a pressure rotator to press against the fixing rotator to form a fixing nip between the fixing rotator and the pressure rotator, the fixing nip through which a recording medium bearing a toner image is conveyed; and a guide, disposed upstream from the fixing nip in a recording medium conveyance direction, to guide the recording medium to the fixing nip, the guide including: a projection extending in the recording medium conveyance direction; a contact face to come into contact with the recording medium; and a roughened face disposed on at least a part of the contact face. ### Claim 2 (depends on 1) The fixing device according to claim 1, wherein the projection includes a rib. ### Claim 3 (depends on 1) The fixing device according to claim 1, wherein the guide further includes a groove being disposed on the projection and extending in the recording medium conveyance direction. ### Claim 4 (depends on 3) The fixing device according to claim 3, wherein the groove includes a slit. ### Claim 5 (depends on 3) The fixing device according to claim 3, wherein the roughened face is a surface of the groove, the surface being treated with emboss processing and having a surface roughness not smaller than 1 micrometer. ### Claim 6 (depends on 3) The fixing device according to claim 3, wherein the groove has a groove width in a width direction perpendicular to the recording medium conveyance direction and the projection has a projection width in the width direction, and wherein a rate of the groove width to the projection width is in a range of from 0.2 to 0.8. ### Claim 7 (depends on 6) The fixing device according to claim 6, wherein the groove has a groove depth in a height direction perpendicular to the recording medium conveyance direction and the width direction and the projection has a projection height in the height direction, and wherein a rate of the groove depth to the projection height is in a range of from 0.2 to 1.0. ### Claim 8 (depends on 7) The fixing device according to claim 7, wherein the projection height is in a range of from 0.5 mm to 1.5 mm. ### Claim 9 (depends on 1) The fixing device according to claim 1, wherein the contact face of the guide is made of liquid crystal polymer. ### Claim 10 (depends on 1) The fixing device according to claim 1, wherein the guide further includes a body separated from the projection. ### Claim 11 (depends on 10) The fixing device according to claim 10, wherein the projection is made of a material having a volume resistivity that is smaller than a volume resistivity of the body. ### Claim 12 (depends on 1) The fixing device according to claim 1, wherein the guide further includes another projection extending in the recording medium conveyance direction and being aligned with the projection in a width direction perpendicular to the recording medium conveyance direction. ### Claim 13 (depends on 1) The fixing device according to claim 1, wherein the roughened face includes a strip being disposed at a downstream end of the contact face in the recording medium conveyance direction and extending in a width direction perpendicular to the recording medium conveyance direction. ### Claim 14 (depends on 13) The fixing device according to claim 13, wherein the strip is treated with emboss processing and has a surface roughness not smaller than 1 micrometer. ### Claim 15 (depends on 1) The fixing device according to claim 1, wherein the projection is detachably attached to the contact face. ### Claim 16 An image forming apparatus comprising: an image forming device to form a toner image; and a fixing device, disposed downstream from the image forming device in a recording medium conveyance direction, to fix the toner image on a recording medium, the fixing device including: a fixing rotator rotatable in a predetermined direction of rotation; a pressure rotator to press against the fixing rotator to form a fixing nip between the fixing rotator and the pressure rotator, the fixing nip through which the recording medium bearing the toner image is conveyed; and a guide, disposed upstream from the fixing nip in the recording medium conveyance direction, to guide the recording medium to the fixing nip, the guide including: a projection extending in the recording medium conveyance direction; a contact face to come into contact with the recording medium; and a roughened face disposed on at least a part of the contact face. ### Claim 17 A fixing device comprising: a fixing rotator; a pressure rotator configured to press against the fixing rotator to form a fixing nip between the fixing rotator and the pressure rotator, the fixing nip being configured to convey a recording medium bearing a toner image therethrough; and a guide, upstream from the fixing nip in a recording medium conveyance direction, configured to guide the recording medium to the fixing nip, the guide including: at least one rib-shaped projection extending in a recording medium conveyance direction; a slit-shaped groove on the at least one rib-shaped projection and extending in the recording medium conveyance direction; and a contact face in contact with the recording medium. ### Claim 18 (depends on 17) The fixing device according to claim 17, wherein: the at least one rib-shaped projection includes, a first projection; and a second projection adjacent to the first projection; and an interval (A) between the first projection and the second projection in an axial direction of the fixing rotator is smaller than a distance (B) from a lateral edge of the guide to the first projection in the axial direction of the fixing rotator. ### Claim 19 (depends on 18) The fixing device according to claim 18, wherein the first projection is parallel to the second projection. ### Claim 20 (depends on 17) The fixing device according to claim 17, wherein the at least one rib-shaped projection includes a slope at an upstream part thereof in the recording medium conveyance direction. ### Claim 21 (depends on 17) The fixing device according to claim 17, wherein the at least one rib-shaped projection includes a first part and a second part on opposite sides of the slit-shaped groove in an axial direction of the fixing rotator. ### Claim 22 (depends on 21) The fixing device according to claim 21, wherein each of the first part and the second part includes: a first wall; and a second wail opposite and parallel to the first wall. ### Claim 23 (depends on 17) An image forming apparatus comprising the fixing device according to claim 17. ### Claim 24 A guide configured to guide a recording medium in a fixing device, the guide comprising: at least one rib-shaped projection extending in a recording medium conveyance direction; a slit-shaped groove on the at least one rib-shaped projection and extending in the recording medium conveyance direction; and a contact face configured to contact the recording medium; the slit-shaped groove having a surface roughness equal to or greater than about 1.0 μm.