# US 2022/0035289 A1 · 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 2022/0035289 A1 - Document ID: US20220035289A1 - Status: Published application - Kind: A1 - Application number: 17/233,749 - Filed: 2021-04-19 - Published: 2022-02-03 - Earliest claimed: 2020-08-03 - Assignees: Toshiba Tec Kabushiki Kaisha - Applicants: Toshiba Tec Kabushiki Kaisha - Inventors: Yohei DOI - Web page: https://patentgrep.com/patent/US20220035289A1 ## CPC - G03G 15/2039: {with means for controlling the fixing temperature} - G03G 15/5004: {Power supply control, e.g. power-saving mode, automatic power turn-off} - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract According to at least one embodiment, an image forming apparatus includes a voltage measuring device, a fixing device, and a controller. The voltage measuring device measures an input voltage. The fixing device includes a heater that heats a sheet. When the measured voltage becomes equal to or greater than a threshold value, the controller determines a heating timing of the heater based on the voltage and activates the heater at the determined heating timing. ## Claims ### Claim 1 An image forming apparatus comprising: a voltage measuring device configured to measure an input voltage; a fixing device comprising a heater configured to heat a sheet; and a controller configured to determine a heating timing of the heater based on the voltage when the measured voltage becomes equal to or greater than a threshold value and to activate the heater at the determined heating timing. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the controller activates the heater when the heating timing is a timing after a peak of an AC voltage input from a power supply. ### Claim 3 (depends on 1) The apparatus of claim 1, further comprising: a zero crossing detection circuit configured to detect a zero crossing point of the AC voltage. ### Claim 4 (depends on 3) The apparatus of claim 3, wherein the controller activates the heater at a time when the heating timing is reached, based on the zero crossing point detected by the zero crossing detection circuit. ### Claim 5 (depends on 1) The apparatus of claim 1, wherein when the voltage measured by the voltage measuring device becomes equal to or greater than a threshold value, the controller executes a sheet printing process by performing a printing control in which an efficiency of a printing operation is reduced. ### Claim 6 (depends on 5) The apparatus of claim 5, wherein the controller is configured to perform at least one of a control for making a sheet conveyance speed slower than a normal conveyance speed, a control for reducing a density during printing, a control that enables printing of a specific sheet type, and a control that enables single-color printing, as a printing control that reduces the efficiency of the printing operation. ### Claim 7 (depends on 6) The apparatus of claim 6, wherein the controller is configured set the normal conveyance speed at a normal time and the sheet conveyance speed slower than the normal conveyance speed in advance, the normal time being a time where no abnormality occurs in the image forming apparatus. ### Claim 8 (depends on 1) The apparatus of claim 1, wherein the voltage measuring device is configured to measure the voltage at a predetermined timing. ### Claim 9 (depends on 8) The apparatus of claim 8, wherein the predetermined timing is at least one of a timing at which the power of the image forming apparatus is turned on and a timing at which the predetermined time is reached. ### Claim 10 (depends on 1) The apparatus of claim 1, wherein the controller is configured to cause a display of a notification indicating an error due to a voltage abnormality, and to execute a printing operation under protection control in response to the error indication. ### Claim 11 A method of printing control processing performed by an image forming apparatus comprising: measuring an input voltage; heating a sheet, via a heater; determining a heating timing of the heater based on the voltage when the measured voltage becomes equal to or greater than a threshold value; and activating the heater at the determined heating timing. ### Claim 12 (depends on 11) The method of claim 11, further comprising: activating the heater when the heating timing is a timing after a peak of an AC voltage input from a power supply. ### Claim 13 (depends on 11) The method of claim 11, further comprising: detecting a zero crossing point of the AC voltage. ### Claim 14 (depends on 13) The method of claim 13, wherein the heater is activated at a time when the heating timing is reached, based on the detected zero crossing point detected. ### Claim 15 (depends on 11) The method of claim 11, further comprising: when the measured voltage becomes equal to or greater than a threshold value, executing a sheet printing process by performing a printing control in which an efficiency of a printing operation is reduced. ### Claim 16 (depends on 15) The method of claim 15, further comprising: at least one of making a sheet conveyance speed slower than a normal conveyance speed, reducing a density during printing, enabling printing of a specific sheet type, and enabling single-color printing, as a printing control that reduces the efficiency of the printing operation. ### Claim 17 (depends on 16) The method of claim 16, further comprising setting in advance the normal conveyance speed at a normal time and the sheet conveyance speed slower than the normal conveyance speed, the normal time being a time where no abnormality occurs in the image forming apparatus. ### Claim 18 (depends on 11) The method of claim 11, further comprising measuring the voltage at a predetermined timing. ### Claim 19 (depends on 18) The method of claim 18, further comprising the predetermined timing is at least one of a timing at which the power of the image forming apparatus is turned on and a timing at which the predetermined time is reached. ### Claim 20 (depends on 11) The method of claim 11, further comprising displaying of a notification indicating an error due to a voltage abnormality, and executing a printing operation under protection control in response to the error indication.