# US 10,870,274 B2 · 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 10,870,274 B2 - Document ID: US10870274B2 - Status: Granted - Kind: B2 - Application number: 16/473,203 - Filed: 2017-12-07 - Published: 2019-12-05 - Granted: 2020-12-22 - Earliest claimed: 2016-12-22 - Assignees: Seiko Epson Corporation - Applicants: Seiko Epson Corporation - Inventors: Katsutomo Tsukahara; Yuma Fukuzawa - Web page: https://patentgrep.com/patent/US10870274B2 ## CPC - B41J 2/14: Structure thereof {only for on-demand ink jet heads} - B41J 2/175: Ink supply systems {; Circuit parts therefor} - B41J 2/14233: {of film type, deformed by bending and disposed on a diaphragm} - B41J 2/18: Ink recirculation systems - B41J 2002/14241: {having a cover around the piezoelectric thin film element} - B41J 2002/14411: {Groove in the nozzle plate} - B41J 2002/14419: {Manifold} - B41J 2202/11: characterised by specific geometrical characteristics - B41J 2202/12: with ink circulating through the whole print head - B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS ## Abstract In a liquid ejecting head, a reduction in mechanical strength due to a liquid chamber provided to circulate a liquid is limited. The liquid ejecting head includes: a nozzle plate provided with a nozzle; a flow channel forming unit provided with a pressure chamber to which a liquid is supplied, a communication channel through which the nozzle and the pressure chamber communicate with each other, and a circulating liquid chamber communicating with the communication channel; and a pressure generating unit that generates a pressure change in the pressure chamber. A height at a first location in the circulating liquid chamber is larger than a height at a second location on a side of the communication channel when viewed from the first location. ## Claims ### Claim 1 A liquid ejecting head comprising: a nozzle plate provided with a nozzle; a flow channel forming unit provided with a pressure chamber to which a liquid is supplied, a communication channel through which the nozzle and the pressure chamber communicate with each other, and a circulating liquid chamber communicating with the communication channel; and a pressure generating unit that generates a pressure change in the pressure chamber, wherein a height at a first location in the circulating liquid chamber is larger than a height at a second location on a side of the communication channel when viewed from the first location, and wherein the circulating liquid chamber has an upper surface provided with a plurality of grooves extending into a curved shape in a plan view. ### Claim 2 (depends on 1) The liquid ejecting head according to claim 1, wherein the circulating liquid chamber does not overlap the pressure chamber in a plan view. ### Claim 3 (depends on 1) The liquid ejecting head according to claim 1, wherein a maximum value of the height of the circulating liquid chamber is smaller than a flow channel length of the communication channel. ### Claim 4 (depends on 1) The liquid ejecting head according to claim 1, wherein the flow channel forming unit has a first flow channel substrate provided with the communication channel and the circulating liquid chamber and a second flow channel substrate provided with the pressure chamber, and wherein a maximum value of the height of the circulating liquid chamber is equal to or smaller than a half of a thickness of the first flow channel substrate. ### Claim 5 (depends on 1) The liquid ejecting head according to claim 1, wherein a maximum value of the height of the circulating liquid chamber is smaller than a width of the circulating liquid chamber. ### Claim 6 (depends on 1) The liquid ejecting head according to claim 1, wherein the circulating liquid chamber elongates in a first direction, and wherein the plurality of grooves has a convex shape on a first side in the first direction in a plan view. ### Claim 7 (depends on 1) The liquid ejecting head according to claim 1, wherein the nozzle plate is provided with a first nozzle and a second nozzle as the nozzle, wherein the flow channel forming unit is provided with the pressure chamber and the communication channel corresponding to the first nozzle, the pressure chamber and the communication channel corresponding to the second nozzle, and the circulating liquid chamber that is positioned between the communication channel corresponding to the first nozzle and the communication channel corresponding to the second nozzle and that elongates in the first direction, and wherein the grooves formed in a region of the upper surface of the circulating liquid chamber on a side of the first nozzle have a convex shape on a first side in the first direction, and the grooves formed in a region on a side of the second nozzle have a convex shape on a second side opposite to the first side in a plan view. ### Claim 8 (depends on 1) The liquid ejecting head according to claim 1, wherein the nozzle plate is provided with a first nozzle and a second nozzle as the nozzle, wherein the flow channel forming unit is provided with the pressure chamber and the communication channel corresponding to the first nozzle, the pressure chamber and the communication channel corresponding to the second nozzle, and the circulating liquid chamber that is positioned between the communication channel corresponding to the first nozzle and the communication channel corresponding to the second nozzle and that elongates in the first direction, and wherein the grooves formed in a region of the upper surface of the circulating liquid chamber on a side of the first nozzle and the grooves formed in a region on a side of the second nozzle have a convex shape on a first side in the first direction in a plan view. ### Claim 9 (depends on 1) The liquid ejecting head according to claim 1, wherein the nozzle plate is provided with a plurality of nozzles arranged in the first direction, wherein the flow channel forming unit is provided with the pressure chamber and the communication channel corresponding to each of the plurality of nozzles and the circulating liquid chamber elongating in the first direction, and wherein grooves of the plurality of grooves which are positioned on a first side in the first direction have a convex shape on a second side opposite to the first side in a plan view, and grooves of the plurality of grooves on the second side in the first direction have a convex shape on the first side in a plan view. ### Claim 10 (depends on 1) The liquid ejecting head according to claim 1, wherein the flow channel forming unit is provided with a first circulating liquid chamber and a second circulating liquid chamber as the circulating liquid chamber, which are positioned on opposite sides of each other with the communication channel interposed therebetween and which communicate with the communication channel. ### Claim 11 (depends on 10) The liquid ejecting head according to claim 10, wherein the first circulating liquid chamber does not overlap the pressure chamber in a plan view, but the second circulating liquid chamber overlaps the pressure chamber in a plan view. ### Claim 12 (depends on 1) The liquid ejecting head according to claim 1, wherein the flow channel forming unit is provided with a liquid supply chamber that stores a liquid that is to be supplied to the pressure chamber, and wherein the maximum value of the height of the circulating liquid chamber is equal to a height of the liquid supply chamber. ### Claim 13 (depends on 1) The liquid ejecting head according to claim 1, wherein a partition wall having a predetermined thickness is provided between the circulating liquid chamber and the communication channel. ### Claim 14 (depends on 1) The liquid ejecting head according to claim 1, wherein the circulating liquid chamber has a first space and a second space formed between flow channel walls, which are opposite to each other, on a side of the communication channel when viewed from the first space, wherein the first location is positioned within the first space, and wherein the second location is positioned within the second space. ### Claim 15 (depends on 1) The liquid ejecting head according to claim 1, further comprising: a wiring substrate having an end portion disposed on an opposite side of the nozzle plate with the flow channel forming unit interposed therebetween, and wherein the circulating liquid chamber overlaps the end portion of the wiring substrate in a plan view. ### Claim 16 (depends on 1) A liquid ejecting apparatus comprising: the liquid ejecting head according to claim 1. ### Claim 17 A liquid ejecting head comprising: a nozzle plate provided with a nozzle; a flow channel forming unit provided with a pressure chamber to which a liquid is supplied, a communication channel through which the nozzle and the pressure chamber communicate with each other, and a circulating liquid chamber communicating with the communication channel; a pressure generating unit that generates a pressure change in the pressure chamber; and a circulation channel through which the communication channel and the circulating liquid channel communicate with each other, wherein a height at a first location in the circulating liquid chamber is larger than a height at a second location on a side of the communication channel when viewed from the first location, and wherein the circulation channel is formed on a surface of the nozzle plate. ### Claim 18 (depends on 17) The liquid ejecting head according to claim 17, wherein the circulating liquid chamber does not overlap the pressure chamber in a plan view. ### Claim 19 (depends on 17) The liquid ejecting head according to claim 17, wherein a maximum value of the height of the circulating liquid chamber is smaller than a flow channel length of the communication channel. ### Claim 20 (depends on 17) The liquid ejecting head according to claim 17, wherein the flow channel forming unit has a first flow channel substrate provided with the communication channel and the circulating liquid chamber and a second flow channel substrate provided with the pressure chamber, and wherein a maximum value of the height of the circulating liquid chamber is equal to or smaller than a half of a thickness of the first flow channel substrate.