# US 2024/0201620 A1 · 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 2024/0201620 A1 - Document ID: US20240201620A1 - Status: Published application - Kind: A1 - Application number: 18/592,169 - Filed: 2024-02-29 - Published: 2024-06-20 - Earliest claimed: 2019-02-08 - Assignees: Toshiba Tec Kabushiki Kaisha - Applicants: Toshiba Tec Kabushiki Kaisha - Inventors: Kazuhiko KIKUCHI - Web page: https://patentgrep.com/patent/US20240201620A1 ## CPC - G03G 15/2025: {with special means for lubricating and/or cleaning the fixing unit, e.g. applying offset preventing fluid} - G03G 15/2039: {with means for controlling the fixing temperature} - G03G 15/205: {specially for the mode of operation, e.g. standby, warming-up, error (G03G15/2046 takes precedence)} - G03G 15/2053: {Structural details of heat elements, e.g. structure of roller or belt, eddy current, induction heating} - G03G 15/2064: {combined with pressure} - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract An image forming apparatus includes a fixing unit including a heater including a first surface and a second surface opposite to the first surface, a fixing belt having a surface to which a lubricant is applied and contacting the first surface through the lubricant, a heat conductor contacting the second surface, and a pressing roller capable of pressing and rotating the fixing belt, a power supply configured to supply electric power to the heater, a first thermometer configured to measure temperature of the heat conductor, and a controller configured to determine a first amount of electric power to be supplied to the heater based on the temperature of the heat conductor, and control the power supply to supply the determined first amount of electric power to the heater, before controlling the pressing roller to start rotation. ## Claims ### Claim 1 An image forming apparatus comprising: a fixing unit including: a heater including a first surface and a second surface opposite to the first surface, a fixing belt having a surface to which a lubricant is applied and contacting the first surface of the heater through the lubricant, a heat conductor contacting the second surface of the heater, and a pressing roller capable of pressing and rotating the fixing belt; a power supply configured to supply electric power to the heater; a first thermometer configured to measure a temperature of the heat conductor; and a controller configured to control the power supply, wherein the controller, before controlling the pressing roller to rotate, controls the power supply to supply to the heater: a first amount of electric power when the temperature of the heat conductor is lower than a first value, a second amount of electric power less than the first amount when the temperature of the heat conductor is higher than or equal to the first value. ### Claim 2 (depends on 1) The image forming apparatus according to claim 1, wherein the heater further includes a first heating element to which the electric power is supplied. ### Claim 3 (depends on 2) The image forming apparatus according to claim 2, further comprising: a second thermometer configured to measure a temperature of the first heating element. ### Claim 4 (depends on 3) The image forming apparatus according to claim 3, wherein the first heating element is disposed at a central portion in a longitudinal direction of the heater. ### Claim 5 (depends on 4) The image forming apparatus according to claim 4, wherein the heater further includes a second heating element arranged adjacent to the first heating element in the longitudinal direction. ### Claim 6 (depends on 5) The image forming apparatus according to claim 5, wherein the second thermometer and the first heating element overlap each other when viewed in a first direction perpendicular to a surface of the fixing belt. ### Claim 7 (depends on 6) The image forming apparatus according to claim 6, further comprising: a third thermometer configured to measure a temperature of the second heating element. ### Claim 8 (depends on 7) The image forming apparatus according to claim 7, wherein the third thermometer and the second heating element overlap each other when viewed in the first direction. ### Claim 9 (depends on 8) The image forming apparatus according to claim 8, wherein the controller controls the power supply to supply electric power to the first heating element and to not supply electric power to the second heating element before controlling the pressing roller to rotate. ### Claim 10 (depends on 8) The image forming apparatus according to claim 8, wherein the heater further includes a third heating element arranged adjacent to the first heating element on an opposite side of the second heating element, and the image forming apparatus further comprises: a first thermostat arranged so as to overlap the first heating element when viewed in the first direction and configured to turn off electric power supplied to the first heating element when the temperature of the first heating element exceeds a predetermined temperature, and a second thermostat arranged so as to overlap the third heating element when viewed in the first direction and configured to turn off electric power supplied to the third heating element when a temperature of the third heating element exceeds the predetermined temperature. ### Claim 11 A method for controlling a fixing unit of an image forming apparatus, the fixing unit including a heater including a first surface and a second surface opposite to the first surface, a fixing belt having a surface to which a lubricant is applied and contacting the first surface of the heater through the lubricant, a heat conductor contacting the second surface of the heater, and a pressing roller capable of pressing and rotating the fixing belt, the method comprising: measuring a temperature of the heat conductor; and before rotating the pressing roller, supplying to the heater: a first amount of electric power when the temperature of the heat conductor is lower than a first value, a second amount of electric power less than the first amount when the temperature of the heat conductor is higher than or equal to the first value. ### Claim 12 (depends on 11) The method according to claim 11, further comprising: measuring a temperature of a first heating element included in the heater. ### Claim 13 (depends on 12) The method according to claim 12, wherein the temperatures of the heat conductor and the first heating element are measured by first and second thermometers, respectively. ### Claim 14 (depends on 13) The method according to claim 13, wherein the first heating element is disposed at a central portion in a longitudinal direction of the heater. ### Claim 15 (depends on 14) The method according to claim 14, wherein the heater further includes a second heating element arranged adjacent to the first heating element in the longitudinal direction. ### Claim 16 (depends on 15) The method according to claim 15, wherein the second thermometer and the first heating element overlap each other when viewed in a first direction perpendicular to a surface of the fixing belt. ### Claim 17 (depends on 16) The method according to claim 16, further comprising: measuring a temperature of the second heating element by a third thermometer. ### Claim 18 (depends on 17) The method according to claim 17, wherein the third thermometer and the second heating element overlap each other when viewed in the first direction. ### Claim 19 (depends on 18) The method according to claim 18, wherein the electric power is supplied to the first heating element and is not supplied to the second heating element before the pressing roller is rotated. ### Claim 20 (depends on 18) The method according to claim 18, wherein the heater further includes a third heating element arranged adjacent to the first heating element on an opposite side of the second heating element, and the method further comprises: turning off electric power supplied to the first heating element by a first thermostat arranged so as to overlap the first heating element when viewed in the first direction when the temperature of the first heating element exceeds a predetermined temperature, and turning off electric power supplied to the third heating element by a second thermostat arranged so as to overlap the third heating element when viewed in the first direction when a temperature of the third heating element exceeds the predetermined temperature.