# US 9,002,219 B2 · Developing apparatus 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 9,002,219 B2 - Document ID: US9002219B2 - Status: Granted - Kind: B2 - Application number: 14/075,200 - Filed: 2013-11-08 - Published: 2014-05-08 - Granted: 2015-04-07 - Earliest claimed: 2012-11-08 - Assignees: Kabushiki Kaisha Toshiba; Toshiba Tec Kabushiki Kaisha - Applicants: Kabushiki Kaisha Toshiba; Toshiba TEC Kabushiki Kaisha - Inventors: Kei Onishi - Web page: https://patentgrep.com/patent/US9002219B2 ## CPC - G03G 15/0849: {Detection or control means for the developer concentration} - G03G 15/0877: {Arrangements for metering and dispensing developer from a developer cartridge into the development unit} - G03G 15/553: {Monitoring or warning means for exhaustion or lifetime end of consumables, e.g. indication of insufficient copy sheet quantity for a job} - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract A developing apparatus includes a development unit configured to supply toner to a photoconductor on which an electrostatic image is formed, a supply unit configured to supply toner to the development unit, a sensor configured to detect a concentration of toner in the development unit, and a control unit. The control unit is configured to, when the detected concentration of the toner is lower than a first value, control the supply unit to perform a toner supply process, control the sensor to detect the concentration of the toner after the toner supply process, count the number of times the sensor detects the concentration of the toner to be higher than a second value that is higher than the first value, and control the supply unit to repeat the toner supply process, when the counted number is less than a predetermined number that is equal to or greater than two. ## Claims ### Claim 1 A developing apparatus, comprising: a development unit configured to supply toner to a photoconductor on which an electrostatic image is formed; a supply unit configured to supply toner to the development unit; a sensor configured to detect a concentration of toner in the development unit; and a control unit configured to, in response to the detected concentration of the toner being lower than a first value: control the supply unit to perform a toner supply process, control the sensor to detect the concentration of the toner after the toner supply process, count the number of times the sensor detects the concentration of the toner to be higher than a second value that is higher than the first value, and control the supply unit to repeat the toner supply process, when the counted number is less than a predetermined number that is equal to or greater than two. ### Claim 2 (depends on 1) The developing apparatus according to claim 1, wherein the control unit is further configured to control the supply unit to stop the toner supply process, when the counted number is greater than the predetermined number. ### Claim 3 (depends on 1) The developing apparatus according to claim 1, wherein the control unit is further configured to count the number of times the toner supply process has been performed, and cause a display to show information, when the counted number of times the toner supply process has been performed is greater than a predetermined number and the detected concentration of the toner is lower than the second value. ### Claim 4 (depends on 1) The developing apparatus according to claim 1, wherein the control unit is further configured to count the number of times the toner supply process has been performed, and control the supply unit to repeat the toner supply process, when the counted number of times the toner supply process has been performed is less than a predetermined number and the detected concentration of the toner is lower than the second value. ### Claim 5 (depends on 1) The developing apparatus according to claim 1, wherein the toner supply process includes a predetermined number of sub-processes, in each of which the supply unit supplies the toner to the development unit for a first period of time and then the development unit circulates the supplied toner therein for a second period of time. ### Claim 6 (depends on 5) The developing apparatus according to claim 5, wherein the predetermined number of the sub-processes corresponds to the number of times the sensor detects the concentration of the toner to be higher the second value. ### Claim 7 (depends on 1) The developing apparatus according to claim 1, further comprising: a memory unit configured to store the first value, the second value, and the predetermined number. ### Claim 8 (depends on 1) The developing apparatus according to claim 1, wherein a control unit is further configured to control the development unit not to supply the toner to the photo conductor until the counted number reaches the predetermined number, when the detected concentration of the toner is lower than the first value. ### Claim 9 A method for controlling an image forming apparatus, including a development unit configured to supply toner to a photoconductor on which an electrostatic image is formed, a supply unit configured to supply toner to the development unit, and a sensor configured to detect a concentration of toner in the development unit, the method comprising: controlling the supply unit to perform a toner supply process, when the detected concentration of the toner is lower than a first value; controlling the sensor to detect the concentration of the toner after the toner supply process; counting the number of times the sensor detects the concentration of the toner to be higher than a second value that is higher than the first value; and controlling the supply unit to repeat the toner supply process, when the counted number is less than a predetermined number that is equal to or greater than two. ### Claim 10 (depends on 9) The method according to claim 9, further comprising: controlling the supply unit to stop the toner supply process, when the counted number is greater than the predetermined number. ### Claim 11 (depends on 9) The method according to claim 9, further comprising: counting the number of times the toner supply process has been performed; and causing a display to show information, when the counted number of times the toner supply process has been performed is greater than a predetermined number and the detected concentration of the toner is lower than the second value. ### Claim 12 (depends on 9) The method according to claim 9, further comprising: counting the number of times the toner supply process has been performed; and controlling the supply unit to repeat the toner supply process, when the counted number of times the toner supply process has been performed is less than a predetermined number and the detected concentration of the toner is lower than the second value. ### Claim 13 (depends on 9) The method according to claim 9, wherein the toner supply process includes a predetermined number of sub-processes, in each of which the supply unit supplies the toner to the development unit for a first period of time and the development unit circulates the supplied toner therein for a second period of time. ### Claim 14 (depends on 13) The method according to claim 13, wherein the predetermined number of the sub-processes corresponds to the number of times the sensor detects the concentration of the toner to be higher the second value. ### Claim 15 (depends on 9) The method according to claim 9, further comprising: storing the first value, the second value, and the predetermined number. ### Claim 16 (depends on 9) The method according to claim 9, further comprising: controlling the development unit not to supply the toner to the photo conductor until the counted number of times reaches the predetermined number, when the detected concentration of the toner is lower than a first value. ### Claim 17 An image forming apparatus, comprising: a photoconductor configured to carry an electrostatic image; a development unit configured to supply toner to the photoconductor; a transfer unit configured to transfer the toner on the photoconductor to a medium; a supply unit configured to supply toner to the development unit; a sensor configured to detect a concentration of toner in the development unit; and a control unit configured to, in response to the detected concentration of the toner being lower than a first value: control the supply unit to perform a toner supply process, control the sensor to detect the concentration of the toner after the toner supply process, count the number of times the sensor detects that the concentration of the toner to be higher than a second value that is higher than the first value, and control the supply unit to repeat the toner supply process, when the counted number is less than a predetermined number that is equal to or greater than two. ### Claim 18 (depends on 17) The image forming apparatus according to claim 17, wherein the control unit is further configured to control the supply unit to stop the toner supply process, when the counted number is greater than the predetermined number. ### Claim 19 (depends on 17) The image forming apparatus according to claim 17, wherein the control unit is further configured to count the number of times the toner supply process has been performed, and cause a display to show information, when the counted number of times the toner supply process has been performed being greater than a predetermined number and the detected concentration of the toner is lower than the second value. ### Claim 20 (depends on 17) The image forming apparatus according to claim 17, wherein the control unit is further configured to count the number of times the toner supply process has been performed, and control the supply unit to repeat the toner supply process, when the counted number of times the toner supply process has been performed is less than a predetermined number of times and the detected concentration of the toner is lower than the second value.