# US 2014/0153940 A1 · Transfer device and image forming apparatus including transfer device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0153940 A1 - Document ID: US20140153940A1 - Status: Published application - Kind: A1 - Application number: 14/092,325 - Filed: 2013-11-27 - Published: 2014-06-05 - Earliest claimed: 2012-11-30 - Assignees: KYOCERA Document Solutions Inc. - Applicants: KYOCERA Document Solutions Inc. - Inventors: Sadanori Nakae - Web page: https://patentgrep.com/patent/US20140153940A1 ## CPC - G03G 15/167: {at least one of the recording member or the transfer member being rotatable during the transfer} - G03G 15/0189: {primary transfer to an intermediate transfer belt (G03G15/0184 takes precedence)} - G03G 15/5054: {by measuring the characteristics of an intermediate image carrying member or the characteristics of an image on an intermediate image carrying member, e.g. intermediate transfer belt or drum, conveyor belt} - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract A transfer device includes an intermediate transfer belt, a driving roller, an environment sensor, a resistance detecting sensor, and a speed ratio adjusting section. The toner images are transferred from the plurality of image carriers onto a surface of the intermediate transfer belt in a superimposed manner. The driving roller circumferentially and rotationally drives the intermediate transfer belt. The environment sensor detects a temperature or a humidity around the intermediate transfer belt. The resistance detecting section detects a change in a resistance value of the intermediate transfer belt. The speed ratio adjusting section controls a rotation speed of the driving roller according to results of detection by the environment sensor and the resistance detecting section, thereby adjusting a speed ratio Vb/Vd between a circumferential rotating speed Vb of the intermediate transfer belt and a rotation speed Vd of the image carrier. ## Claims ### Claim 1 A transfer device comprising: an intermediate transfer belt disposed to face a plurality of image carriers each carrying a toner image on a circumferential surface of the image carrier and moreover rotationally driven at an equal speed, the intermediate transfer belt being circumferentially and rotationally driven in one direction, the toner images being transferred from the plurality of image carriers onto a surface of the intermediate transfer belt in a superimposed manner; a driving roller around which the intermediate transfer belt is supported and which circumferentially and rotationally drives the intermediate transfer belt; an environment sensor detecting a temperature or a humidity around the intermediate transfer belt; a resistance detecting section detecting a change in a resistance value of the intermediate transfer belt; and a speed ratio adjusting section controlling a rotation speed of the driving roller according to results of detection by the environment sensor and the resistance detecting section, thereby adjusting a speed ratio Vb/Vd between a circumferential rotating speed Vb of the intermediate transfer belt and a rotation speed Vd of the image carrier. ### Claim 2 (depends on 1) The transfer device according to claim 1, wherein the speed ratio adjusting section sets the speed ratio Vb/Vd to a first speed ratio when the temperature or humidity detected by the environment sensor is lower than a preset threshold, and sets the speed ratio Vb/Vd to a second speed ratio, which is higher than the first speed ratio, when the temperature or humidity is equal to or higher than a preset threshold. ### Claim 3 (depends on 2) The transfer device according to claim 2, wherein the speed ratio adjusting section sets the speed ratio Vb/Vd to a third speed ratio, which is higher than the first speed ratio and lower than the second speed ratio when the resistance detecting section detects that the resistance value of the intermediate transfer belt is greater than a preset threshold. ### Claim 4 (depends on 3) The transfer device according to claim 3, wherein the first speed ratio is lower than 1.0. ### Claim 5 (depends on 4) The transfer device according to claim 4, wherein the first speed ratio is equal to or higher than 0.75 and equal to or lower than 0.85. ### Claim 6 (depends on 4) The transfer device according to claim 4, wherein the second speed ratio is equal to or higher than 1.0. ### Claim 7 (depends on 6) The transfer device according to claim 6, wherein the second speed ratio is equal to or higher than 1.05 and equal to or lower than 1.15. ### Claim 8 (depends on 3) The transfer device according to claim 3, wherein the third speed ratio is lower than 1.0. ### Claim 9 (depends on 8) The transfer device according to claim 8, wherein the third speed ratio is equal to or higher than 0.85 and equal to or lower than 0.95. ### Claim 10 (depends on 1) The transfer device according to claim 1, wherein the resistance detecting section is a belt density sensor that detects a density of a belt surface of the intermediate transfer belt. ### Claim 11 (depends on 10) The transfer device according to claim 10, wherein the belt density sensor also serves as a toner density sensor that detects a density of a toner image formed on the intermediate transfer belt. ### Claim 12 (depends on 1) The transfer device according to claim 1, wherein the driving roller is a metal roller. ### Claim 13 (depends on 12) The transfer device according to claim 12, wherein the driving roller includes a layer disposed on a surface of the driving roller and formed of alumite. ### Claim 14 (depends on 4) The transfer device according to claim 4, further comprising: a plurality of primary transfer rollers each disposed to face the image carrier across the intermediate transfer belt and forming a transfer nip between the primary transfer roller and the image carrier; the driving roller forming a secondary transfer nip where the toner image is transferred from the intermediate transfer belt to a sheet; and a backup roller disposed between the driving roller and the primary transfer roller located on a most downstream side among the plurality of primary transfer rollers in the circumferential rotating direction of the intermediate transfer belt, the intermediate transfer belt being supported around the backup roller. ### Claim 15 (depends on 3) The transfer device according to claim 3, wherein the resistance detecting section is a belt density sensor that detects a density of a belt surface of the intermediate transfer belt, and the speed ratio adjusting section determines that the resistance value of the intermediate transfer belt is greater than the preset threshold when the belt density sensor detects that the belt surface is whitened. ### Claim 16 An image forming apparatus comprising: a transfer device having an intermediate transfer belt; a plurality of image carriers each disposed to face the intermediate transfer belt and carrying a toner image on a peripheral surface of the image carrier and moreover rotationally driven at an equal speed; and a secondary transfer roller transferring the toner image from the intermediate transfer belt to a sheet, wherein the transfer device includes: an intermediate transfer belt circumferentially and rotationally driven in one direction, the toner images being transferred from the plurality of image carriers onto a surface of the intermediate transfer belt in a superimposed manner; a driving roller around which the intermediate transfer belt is supported and which circumferentially and rotationally drives the intermediate transfer belt; an environment sensor detecting a temperature or a humidity around the intermediate transfer belt; a resistance detecting section detecting a change in a resistance value of the intermediate transfer belt; and a speed ratio adjusting section controlling a rotation speed of the driving roller according to results of detection by the environment sensor and the resistance detecting section, thereby adjusting a speed ratio Vb/Vd between a circumferential rotating speed Vb of the intermediate transfer belt and a rotation speed Vd of the image carrier. ### Claim 17 (depends on 16) The image forming apparatus according to claim 16, wherein the speed ratio adjusting section sets the speed ratio Vb/Vd to a first speed ratio when the temperature or humidity detected by the environment sensor is lower than a preset threshold, and sets the speed ratio Vb/Vd to a second speed ratio, which is higher than the first speed ratio, when the temperature or humidity is equal to or higher than a preset threshold. ### Claim 18 (depends on 17) The image forming apparatus according to claim 17, wherein the speed ratio adjusting section sets the speed ratio Vb/Vd to a third speed ratio, which is higher than the first speed ratio and lower than the second speed ratio, when the resistance detecting section detects that the resistance value of the intermediate transfer belt is greater than a preset threshold. ### Claim 19 (depends on 16) The image forming apparatus according to claim 16, wherein the resistance detecting section is a belt density sensor that detects a density of a belt surface of the intermediate transfer belt. ### Claim 20 (depends on 16) The image forming apparatus according to claim 16, wherein the driving roller is a metal roller.