# US 10,369,785 B2 · Inkjet printhead device, fluid ejection device, and method thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,369,785 B2 - Document ID: US10369785B2 - Status: Granted - Kind: B2 - Application number: 15/793,778 - Filed: 2017-10-25 - Published: 2018-02-15 - Granted: 2019-08-06 - Earliest claimed: 2016-03-28 - Assignees: Hewlett-Packard Development Company, L.P. - Applicants: Hewlett-Packard Development Company, L.P. - Inventors: Andrew L. Van Brocklin; Adam L. Ghozeil; Daryl E. Anderson - Web page: https://patentgrep.com/patent/US10369785B2 ## CPC - B41J 2/04573: {Timing; Delays} - B41J 2/0451: {for detecting failure, e.g. clogging, malfunctioning actuator} - B41J 2/0458: {controlling heads based on heating elements forming bubbles} - B41J 2/04581: {controlling heads based on piezoelectric elements} - B41J 2/14153: {Structures including a sensor} - B41J 2/17566: {Ink level or ink residue control} - G01F 23/185: {for discrete levels} - B41J 2002/17579: {Measuring electrical impedance for ink level indication} - B41J 2202/07: dealing with air bubbles - B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS - G01F: MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME ## Abstract An inkjet printhead device, fluid ejection device and method thereof are disclosed. The fluid ejection device includes a fluid supply chamber to store fluid, an ejection chamber including a nozzle and a corresponding ejection member to selectively eject the fluid through the nozzle, and a channel to establish fluid communication between the fluid supply chamber and the ejection chamber. The fluid ejection device also includes a pressure sensor unit having a sensor plate to output a voltage value corresponding to a cross-sectional area of an amount of fluid in the at least ejection chamber. ## Claims ### Claim 1 A fluid ejection device, comprising: a plurality of ejection chambers comprising nozzles and corresponding ejection members to selectively eject a fluid through the respective nozzles by forming a vapor bubble in an ejection chamber which forces a fluid drop out the corresponding nozzle, wherein: a diameter of a nozzle in a test ejection chamber is greater than a diameter of a nozzle in a non-test ejection chamber; and the test ejection chamber comprises a pressure sensor plate. ### Claim 2 (depends on 1) The fluid ejection device of claim 1, wherein the pressure sensor plate outputs a voltage proportional to a change in back pressure. ### Claim 3 (depends on 1) The fluid ejection device of claim 1, wherein pressure sensor plates are located just in test chambers. ### Claim 4 (depends on 1) The fluid ejection device of claim 1, further comprising a refill determination module to determine an amount of time to refill at least one ejection chamber. ### Claim 5 (depends on 4) The fluid ejection device of claim 4, further comprising a count determination module to determine a supply condition based on an output from the refill determination module. ### Claim 6 (depends on 5) The fluid ejection device of claim 5, wherein the supply condition is a pre-exhaustion condition. ### Claim 7 (depends on 1) A method for detecting a pre-exhaustion condition of an ink reservoir associated with the fluidic ejection device of claim 1, the method comprising: measuring at least one of: a firing chamber pressure and a firing chamber refill time; comparing the measurement with previous measurements; determining based on the comparison that the ink reservoir is in a pre-exhaustion condition, wherein the determination is based on at least one of: a marked rise in refill time and a marked decrease in firing chamber pressure; and providing a notice of the detected pre-exhaustion condition in a user detectable format. ### Claim 8 (depends on 7) The method of claim 7, wherein the measuring and determination are based on refill time. ### Claim 9 (depends on 7) The method of claim 7, wherein the measuring and determination are based on firing chamber pressure. ### Claim 10 A fluid ejection device, comprising: a plurality of ejection chambers comprising nozzles and corresponding ejection members to selectively eject a fluid through the respective nozzles by forming a vapor bubble in an ejection chamber which forces a fluid drop out the corresponding nozzle, wherein: a first subset of the ejection chambers are test ejection chambers; a second subset of the ejection chambers are non-test ejection chambers; the test ejection chambers: have nozzles with diameters greater than diameters of nozzles of the non-test ejection chambers; and comprise a pressure sensor plate; and a number of pressure sensor units comprising at least one pressure sensor plate to output a voltage value corresponding to a cross-sectional area of an amount of fluid in at least one ejection chamber. ### Claim 11 (depends on 10) The fluid ejection device of claim 10, wherein the pressure sensor unit further comprises a current source, a grounding member, and a converter module. ### Claim 12 (depends on 10) The fluid ejection device of claim 10, wherein the number of pressure sensor units comprises multiple pressure sensor units corresponding to the number of test chambers. ### Claim 13 (depends on 10) The fluid ejection device of claim 10, wherein: the number of pressure sensor units comprises a single pressure sensor unit; and the pressure sensor unit comprises multiple pressure sensor plates corresponding to the number of test chambers. ### Claim 14 (depends on 13) The fluid ejection device of claim 13, wherein each test chamber includes a pressure sensor plate. ### Claim 15 (depends on 10) The fluid ejection device of claim 10, wherein pressure sensor plates are located just in test chambers. ### Claim 16 A fluid ejection device, comprising: a plurality of ejection chambers comprising nozzles and corresponding ejection members to selectively eject a fluid through the respective nozzles by forming a vapor bubble in an ejection chamber which forces a fluid drop out the corresponding nozzle; a pressure sensor plate coupled to an ejection chamber of the plurality of ejection chambers; a refill determination module to determine an amount of time to refill a number of ejection chambers; and a count determination module to determine a supply condition based on an output from the refill determination module. ### Claim 17 (depends on 16) The fluid ejection device of claim 16, wherein the supply condition is a pre-exhaustion condition. ### Claim 18 (depends on 17) The fluid ejection device of claim 17, comprising a pressure sensor unit to detect refill time and the amount of fluid in ejection chamber with respect to a predetermined time over successive firing cycles. ### Claim 19 (depends on 18) The fluidic ejection device of claim 18, comprising: a circuit or a number of interconnected circuits to implement a logical function; a memory with machine-readable instructions stored thereon, that, when executed by the circuit or number of interconnected circuits, causes the circuit or number of interconnected circuits to: measure at least one of: a firing chamber pressure and a firing chamber refill time; compare the measurement with previous measurements; determine based on the comparison that an ink reservoir is in a pre-exhaustion condition, wherein the determination is based on at least one of: a marked rise in refill time and a marked decrease in firing chamber pressure; and provide a notice of the detected pre-exhaustion condition in a user detectable format.