# US 11,029,623 B2 · Powder amount detector including a pair of measuring electrodes > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,029,623 B2 - Document ID: US11029623B2 - Status: Granted - Kind: B2 - Application number: 16/914,720 - Filed: 2020-06-29 - Published: 2021-02-04 - Granted: 2021-06-08 - Earliest claimed: 2019-07-31 - Assignees: Ricoh Company, Ltd. - Applicants: Tatsuya Kubo; Junichi Matsumoto; Shuntaroh Tamaki; Hiroaki Okamoto - Inventors: Tatsuya Kubo; Junichi Matsumoto; Shuntaroh Tamaki; Hiroaki Okamoto - Web page: https://patentgrep.com/patent/US11029623B2 ## CPC - G03G 15/0856: {Detection or control means for the developer level} - G03G 15/086: {the level being measured by electro-magnetic means} - G03G 21/203: {Humidity} - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract A powder amount detector detects an amount of powder in a powder container of a cylindrical shape arranged horizontally. The powder amount detector includes a pair of measuring electrodes configured to detect capacitance between the pair of measuring electrodes to detect the amount of powder. The pair of measuring electrodes is disposed around the powder container. One of the pair of measuring electrodes has a flat shape, and the other of the pair of measuring electrodes has an arc shape following a shape of the powder container. ## Claims ### Claim 1 A powder amount detector configured to detect an amount of powder in a powder container of a cylindrical shape arranged horizontally, the powder amount detector comprising: a pair of measuring electrodes configured to detect capacitance between the pair of measuring electrodes to detect the amount of powder, the pair of measuring electrodes disposed outside the powder container, one of the pair of measuring electrodes having a flat shape, and another of the pair of measuring electrodes having an arc shape following a shape of the powder container. ### Claim 2 (depends on 1) The powder amount detector according to claim 1, wherein the pair of measuring electrodes is arranged below and above the powder container in a vertical direction. ### Claim 3 (depends on 2) The powder amount detector according to claim 2, wherein projected areas of the pair of measuring electrodes projected in the vertical direction have a same size. ### Claim 4 (depends on 1) The powder amount detector according to claim 1, further comprising ground electrodes disposed outboard of the pair of measuring electrodes and grounded electrically. ### Claim 5 (depends on 1) The powder amount detector according to claim 1, further comprising a memory to store a calibration curve indicating a relation between the capacitance between the pair of measuring electrodes and the amount of powder in the powder container, wherein the powder amount detector is further configured to detect the amount of powder in the powder container based on the calibration curve and the capacitance between the pair of measuring electrodes, and wherein the powder amount detector is further configured to measure the capacitance between the pair of measuring electrodes in at least two states in which the amount of powder between the pair of measuring electrodes is different from each other to acquire the calibration curve. ### Claim 6 (depends on 1) The powder amount detector according to claim 1, further comprising: a memory to store a calibration curve indicating a relation between the capacitance between the pair of measuring electrodes and the amount of powder in the powder container; and a temperature and humidity sensor configured to detect temperature and humidity, wherein the powder amount detector is further configured to detect the amount of powder in the powder container based on the calibration curve, the capacitance between the pair of measuring electrodes, and the temperature and humidity detected by the temperature and humidity sensor. ### Claim 7 (depends on 1) A powder supply device comprising: the powder amount detector according to claim 1; and the powder container, wherein the powder supply device is configured to supply powder in the powder container. ### Claim 8 (depends on 7) The powder supply device according to claim 7, further comprising a rotary drive device configured to rotate the powder container. ### Claim 9 (depends on 7) The powder supply device according to claim 7, further comprising a plurality of powder containers, including the powder container, arranged in parallel; a plurality of powder amount detectors, including the powder amount detector, provided corresponding to the plurality of powder containers, respectively; and a plurality of ground electrodes disposed between the plurality of powder containers and electrically grounded. ### Claim 10 (depends on 7) An image forming apparatus comprising: an image bearer configured to bear a latent image; a developing device configured to develop the latent image on the image bearer with a developer; the powder container configured to contain the developer to be used in the developing device; and the powder supply device according to claim 7 configured to supply the developer in the powder container to the developing device. ### Claim 11 (depends on 7) The powder supply device of claim 7, wherein the pair of measuring electrodes is arranged below and above the powder container in a vertical direction. ### Claim 12 (depends on 11) The powder supply device of claim 11, wherein projected areas of the pair of measuring electrodes projected in the vertical direction have a same size. ### Claim 13 (depends on 10) The image forming apparatus of claim 10, wherein the pair of measuring electrodes is arranged below and above the powder container in a vertical direction. ### Claim 14 (depends on 13) The image forming apparatus of claim 13, wherein projected areas of the pair of measuring electrodes projected in the vertical direction have a same size.