# US 12,007,715 B1 · 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 12,007,715 B1 - Document ID: US12007715B1 - Status: Granted - Kind: B1 - Application number: 18/189,088 - Filed: 2023-03-23 - Granted: 2024-06-11 - Earliest claimed: 2023-03-23 - Assignees: Toshiba Tec Kabushiki Kaisha - Applicants: Toshiba Tec Kabushiki Kaisha - Inventors: Masafumi Yoshida; Takashi Ogiwara - Web page: https://patentgrep.com/patent/US12007715B1 ## CPC - G03G 21/20: Humidity or temperature control {also ozone evacuation; Internal apparatus environment control} - G03G 15/0121: {for developing} - G03G 15/065: {Arrangements for controlling the potential of the developing electrode} - G03G 15/5033: {by measuring the photoconductor characteristics, e.g. temperature, or the characteristics of an image on the photoconductor} - G03G 2215/0103: Plural electrographic recording members - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract An image forming apparatus includes multiple developing devices, a temperature sensor, and a controller. The multiple developing devices are configured to respectively develop electrostatic latent images formed on an image carrier and correspond to multiple colors. The temperature sensor is configured to measure a temperature of a first developing device of the multiple developing devices that develops at least a first color of the multiple colors. The controller includes a processor and a memory. The controller is configured to: stop development performed by the first developing device based on the measured temperature of the first developing device; and operate a second developing device of the multiple developing devices to perform development when the first developing device is stopped. ## Claims ### Claim 1 An image forming apparatus, comprising: a plurality of developing devices configured to respectively develop electrostatic latent images formed on an image carrier, the plurality of developing devices corresponding to a plurality of colors; a temperature sensor configured to measure a temperature of a first developing device of the plurality of developing devices that develops at least a first color of the plurality of colors; and a controller comprising a processor and a memory, the controller configured to: stop development performed by the first developing device based on the measured temperature of the first developing device; and operate a second developing device of the plurality of developing devices to perform development when the first developing device is stopped. ### Claim 2 (depends on 1) The image forming apparatus of claim 1, wherein the controller is configured to operate a third developing device of the plurality of developing devices to perform development when the first developing device is stopped. ### Claim 3 (depends on 1) The image forming apparatus of claim 1, wherein the controller is configured to: determine whether to operate the second developing device when the first developing device is stopped; and operate the second developing device to perform development based on the determination. ### Claim 4 (depends on 1) The image forming apparatus of claim 1, wherein the controller is configured to: receive a selection of a second color from a subset of the plurality of colors that are developable when the first developing device is stopped; and operate the second developing device to perform development, the second developing device configured to develop the second color. ### Claim 5 (depends on 1) The image forming apparatus of claim 1, wherein the controller is configured to operate the second developing device and a third developing device of the plurality of developing devices when the first developing device is stopped, wherein the second developing device and the third developing device are configured to develop the first color. ### Claim 6 (depends on 1) The image forming apparatus of claim 1, wherein the controller is configured to: subsequent to stopping the first developing device, restart development via the first developing device based on a temperature of the first developing device measured subsequent to the first developing device being stopped. ### Claim 7 (depends on 1) The image forming apparatus of claim 1, wherein the controller is configured to: set any one of a plurality of modes including a first mode in which monochrome development is performed by one developing device of the plurality of developing devices and a second mode in which multi-color development is performed by the plurality of developing devices; enable development by one of the plurality of developing devices when the first developing device is stopped and when the first mode is set by the controller, and prevent the one developing device from performing development while the first developing device is stopped and when the second mode is set by the controller. ### Claim 8 (depends on 1) The image forming apparatus of claim 1, wherein the controller is configured to: acquire, via the temperature sensor, a temperature of the first developing device based on a temperature of the image carrier. ### Claim 9 (depends on 8) The image forming apparatus of claim 8, wherein the temperature sensor is in contact with the image carrier at a position downstream of the first developing device in a moving direction of the image carrier. ### Claim 10 (depends on 8) The image forming apparatus of claim 8, wherein the temperature sensor is disposed apart from the image carrier and is configured to detect an ambient temperature of the image carrier. ### Claim 11 An image forming apparatus, comprising: an image carrier; a plurality of developing devices configured to respectively develop electrostatic latent images formed on the image carrier, the plurality of developing devices comprising: a first developing device configured to develop a first color of a plurality of colors; a second developing device configured to develop a second color of the plurality of colors; a third developing device configured to develop a third color of the plurality of colors; a temperature sensor configured to measure a temperature of the first developing device; and a controller comprising a processor and a memory, the controller configured to: obtain a threshold value regarding the temperature of the first developing device; stop development performed by the first developing device based on a comparison between the temperature of the first developing device and the threshold value; and operate the second developing device to perform development when the first developing device is stopped. ### Claim 12 (depends on 11) The image forming apparatus of claim 11, wherein the controller is configured to operate the third developing device to perform development when the first developing device is stopped. ### Claim 13 (depends on 11) The image forming apparatus of claim 11, wherein the controller is configured to: determine whether to operate the second developing device when the first developing device is stopped; and operate the second developing device to perform development based on the determination. ### Claim 14 (depends on 11) The image forming apparatus of claim 11, wherein the controller is configured to: receive a selection of a color from a subset of the plurality of colors that are developable when the first developing device is stopped; and operate the second developing device to perform development of the color from the subset of the plurality of colors. ### Claim 15 (depends on 11) The image forming apparatus of claim 11, wherein the controller is configured to operate the second developing device and the third developing device when the first developing device is stopped, and wherein the second developing device and the third developing device are configured to develop the first color. ### Claim 16 (depends on 11) The image forming apparatus of claim 11, wherein the controller is configured to: resume development via the first developing device based on a comparison between the temperature of the first developing device and the threshold value. ### Claim 17 (depends on 11) The image forming apparatus of claim 11, wherein the controller is configured to acquire, via the temperature sensor, a temperature of the first developing device based on a temperature of the image carrier. ### Claim 18 A method, comprising: obtaining, via a processor of an image forming apparatus, a threshold value regarding the temperature of a first developing device of a plurality of developing devices; stopping, via the processor, development performed by the first developing device based on a comparison between the temperature of the first developing device and the threshold value; and operating, via the processor, a second developing device of the plurality of developing devices to perform development when the first developing device is stopped. ### Claim 19 (depends on 18) The method of claim 18, further comprising determining, via the processor, whether to operate the second developing device when the first developing device is stopped; and operating, via the processor, the second developing device to perform development based on the determination. ### Claim 20 (depends on 18) The method of claim 18, further comprising determining, via the processor, whether to operate the second developing device when the first developing device is stopped; and operating, via the processor, the second developing device to perform development based on the determination; wherein the threshold value comprises a first threshold value and a second threshold value.