# US 12,759,286 B2 · Abnormality determination method for liquid ejecting head, and liquid ejecting apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,759,286 B2 - Document ID: US12759286B2 - Status: Granted - Kind: B2 - Application number: 18/616,987 - Filed: 2024-03-26 - Published: 2024-10-03 - Granted: 2026-10-13 - Earliest claimed: 2023-03-29 - Assignees: Seiko Epson Corporation - Applicants: Seiko Epson Corporation - Inventors: Siyuan Xu; Akira Miyagishi - Web page: https://patentgrep.com/patent/US12759286B2 ## CPC - B41J 2/0451: {for detecting failure, e.g. clogging, malfunctioning actuator} - B41J 2/04581: {controlling heads based on piezoelectric elements} - B41J 2/04588: {using a specific waveform} - B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS ## Abstract An abnormality determination method for a liquid ejecting head including a plurality of ejecting portions including a nozzle, a pressure chamber, a first electrode, a second electrode, and a piezoelectric body, and a liquid storage portion that communicates with each of the plurality of ejecting portions, the method including: holding a voltage between the first electrode and the second electrode of a first ejecting portion at a constant voltage in a first period; supplying a drive signal for applying a pressure fluctuation to the liquid in the pressure chamber of a second ejecting portion, to one of the first electrode and the second electrode of the second ejecting portion in the first period; detecting a residual vibration of the first ejecting portion, in a second period following the first period; and determining whether or not the liquid ejecting head has an abnormality based on the residual vibration. ## Claims ### Claim 1 An abnormality determination method for a liquid ejecting head that includes a liquid storage portion that is configured to store a liquid, and a plurality of ejecting portions including at least a first ejecting portion and a second ejecting portion that is different than the first ejecting portion, wherein each of the plurality of ejecting portions includes a nozzle that ejects the liquid, a pressure chamber that communicates with the nozzle, a first electrode, a second electrode, a piezoelectric body that is disposed between the first electrode and the second electrode and is driven to apply a pressure fluctuation to the liquid in the pressure chamber and an individual flow path, wherein the liquid storage portion communicates with the pressure chamber of each of the plurality of ejecting portions via the respective individual flow path, the method comprising: in a first period, holding a constant voltage between the first electrode and the second electrode of the first ejecting portion; supplying a drive signal including a drive pulse to one of the first electrode and the second electrode of the first ejecting portion in the first period, to thereby apply a pressure fluctuation to the liquid in the pressure chamber of the second ejecting portion; in a second period following the first period, detecting a residual vibration resulting from the pressure change in the liquid in the pressure chamber of the second ejecting portion, the residual vibration occurring within the liquid of the pressure chamber of the first ejecting portion after vibration from the pressure change propagates from the pressure chamber of the second ejecting portion, through the individual flow path of the second ejecting portion, through the liquid storage portion, through the individual flow path of the first ejecting portion, and into the pressure chamber of the first ejecting portion; and determining whether or not the liquid ejecting head has an abnormality based on the residual vibration. ### Claim 2 (depends on 1) The abnormality determination method for a liquid ejecting head according to claim 1, wherein determining whether or not the liquid storage portion of the liquid ejecting head has an abnormality is based on the residual vibration. ### Claim 3 (depends on 1) The abnormality determination method for a liquid ejecting head according to claim 1, wherein the drive pulse is an ejection pulse for ejecting a droplet from the nozzle of the second ejecting portion. ### Claim 4 (depends on 1) The abnormality determination method for a liquid ejecting head according to claim 1, wherein in the second period, a voltage between the first electrode and the second electrode of the second ejecting portion is held at a constant voltage. ### Claim 5 (depends on 1) The abnormality determination method for a liquid ejecting head according to claim 1, further comprising: determining, before the first period, whether or not each of the plurality of ejecting portions has an abnormality includes determining that the first ejecting portion is normal and determining that the second ejecting portion is normal, and in response to determining that the first ejecting portion is normal, selecting the first ejecting portion as the ejecting portion in which residual vibrations are to be detected in the first period; and in response to determining that the second ejecting portion is normal, selecting the second ejecting portion as the ejecting portion to which the drive signal is applied in the first period. ### Claim 6 (depends on 1) The abnormality determination method for a liquid ejecting head according to claim 1, the plurality of ejecting portions further including a third ejecting portion, which is an ejecting portion adjacent to the first ejecting portion and different from the second ejecting portion, the method further comprising: in the first period and the second period, holding a constant voltage between the first electrode and the second electrode of the third ejecting portion. ### Claim 7 (depends on 1) The abnormality determination method for a liquid ejecting head according to claim 1, the plurality of ejecting portions further including a first subgroup of ejecting portions that are continuously arranged adjacent to the first ejecting portion and different than the second ejecting portion, the method further comprising: in the first period and the second period, a voltage between the first electrode and the second electrode of each of the ejecting portions of the first subgroup. ### Claim 8 (depends on 7) The abnormality determination method for a liquid ejecting head according to claim 7, wherein the number of the second ejecting portions is more than the number of ejecting portions of the first subgroup. ### Claim 9 (depends on 1) The abnormality determination method for a liquid ejecting head according to claim 1, wherein the drive signal includes a plurality of drive pulses for applying a pressure fluctuation to the liquid in the pressure chamber of the second ejecting portion in the first period. ### Claim 10 (depends on 1) The abnormality determination method for a liquid ejecting head according to claim 1, wherein the detection including the first period and the second period is performed a plurality of times, in each of the plurality of times of the detection, a different ejecting portion is set as the first ejecting portion, and the determination of whether or not the liquid ejecting head has the abnormality is determined based on the residual vibration detected in the second period of each of the plurality of times of the detection. ### Claim 11 (depends on 1) The abnormality determination method for a liquid ejecting head according to claim 1, wherein whether or not the liquid ejecting head has the abnormality is determined based on a comparison result between a predetermined reference residual vibration and the residual vibration detected in the second period. ### Claim 12 (depends on 1) The abnormality determination method for a liquid ejecting head according to claim 1, wherein whether or not the liquid ejecting head has the abnormality is determined based on a comparison result between a reference amplitude value indicated by reference information prepared in advance and an amplitude value of the residual vibration detected in the second period. ### Claim 13 (depends on 12) The abnormality determination method for a liquid ejecting head according to claim 12, wherein the reference amplitude value is determined based on an amplitude value of a reference residual vibration measured in advance, the first ejecting portion in the first period and the second period is an ejecting portion at the same position as the first ejecting portion when the reference residual vibration is measured, and the second ejecting portion in the first period and the second period is an ejecting portion at the same position as the second ejecting portion when the reference residual vibration is measured. ### Claim 14 (depends on 13) The abnormality determination method for a liquid ejecting head according to claim 13, wherein the liquid storage portion includes a compliance portion that absorbs a vibration of the stored liquid, the reference amplitude value includes a first amplitude value, and when the amplitude value of the residual vibration detected in the second period is more than the first amplitude value, it is determined that the compliance portion has an abnormality. ### Claim 15 (depends on 13) The abnormality determination method for a liquid ejecting head according to claim 13, wherein the reference amplitude value includes a second amplitude value, and when the amplitude value of the residual vibration detected in the second period is less than the second amplitude value, it is determined that an air bubble exists in the liquid storage portion. ### Claim 16 (depends on 1) The abnormality determination method for a liquid ejecting head according to claim 1, wherein whether or not the liquid ejecting head has the abnormality is determined based on a comparison result between a reference period indicated by reference information prepared in advance and a period of the residual vibration detected in the second period. ### Claim 17 (depends on 16) The abnormality determination method for a liquid ejecting head according to claim 16, wherein the reference period is determined based on a period of a reference residual vibration measured in advance, the first ejecting portion in the first period and the second period is an ejecting portion at the same position as the first ejecting portion when the reference residual vibration is measured, and the second ejecting portion in the first period and the second period is an ejecting portion at the same position as the second ejecting portion when the reference residual vibration is measured. ### Claim 18 (depends on 16) The abnormality determination method for a liquid ejecting head according to claim 16, wherein the liquid storage portion includes a compliance portion that absorbs a vibration of the stored liquid, the reference period includes a first period, and when the period of the residual vibration detected in the second period is less than the first period, it is determined that the compliance portion has an abnormality. ### Claim 19 (depends on 16) The abnormality determination method for a liquid ejecting head according to claim 16, wherein the reference period includes a second period, and when an amplitude value of the residual vibration detected in the second period is more than the second period, it is determined that an air bubble exists in the liquid storage portion. ### Claim 20 A liquid ejecting apparatus comprising: a liquid ejecting head; a determination portion that is configured to determine whether or not the liquid ejecting head has an abnormality; and a control portion that is configured to control the liquid ejecting head and the determination portion, wherein the liquid ejecting head includes a plurality of ejecting portions including at least a first ejecting portion and a second ejecting portion, each of the plurality of ejecting portions including a nozzle that ejects a liquid, a pressure chamber that communicates with the nozzle, a first electrode, a second electrode, a piezoelectric body that is disposed between the first electrode and the second electrode and is driven to apply a pressure fluctuation to the liquid in the pressure chamber, and an individual flow path, and a liquid storage portion that stores liquid and communicates with the pressure chamber of each of the plurality of ejecting portions via the respective individual flow path, the control portion is configured to control the liquid ejecting head to hold, in a first period, a constant voltage between the first electrode and the second electrode of the first ejecting portion, supply, in the first period, a drive signal including a drive pulse to one of the first electrode and the second electrode of the first ejecting portion, to thereby apply a pressure fluctuation to the liquid in the pressure chamber of the second ejecting portion, and detect, in a second period following the first period, a residual vibration resulting from the pressure change in the liquid in the pressure chamber of the second ejecting portion, the residual vibration occurring within the liquid of the pressure chamber of the first ejecting portion after vibration from the pressure change propagates from the pressure chamber of the second ejecting portion, through the individual flow path of the second ejecting portion, through the liquid storage portion, through the individual flow path of the first ejecting portion, and into the pressure chamber of the first ejecting portion, and the determination portion determines whether or not the liquid ejecting head has an abnormality based on the residual vibration.