# US 11,077,688 B2 · Liquid discharge head and liquid discharge apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,077,688 B2 - Document ID: US11077688B2 - Status: Granted - Kind: B2 - Application number: 16/572,079 - Filed: 2019-09-16 - Published: 2020-03-26 - Granted: 2021-08-03 - Earliest claimed: 2018-09-20 - Assignees: Ricoh Company, Ltd. - Applicants: Masami Iwama; Shiomi Andou; Satoru Yoshida - Inventors: Masami Iwama; Shiomi Andou; Satoru Yoshida - Web page: https://patentgrep.com/patent/US11077688B2 ## CPC - B41J 29/377: Cooling or ventilating arrangements - B41J 2/04515: {preventing overheating} - B41J 2/14233: {of film type, deformed by bending and disposed on a diaphragm} - B41J 2/14274: {of stacked structure type, deformed by compression/extension and disposed on a diaphragm} - B41J 2/175: Ink supply systems {; Circuit parts therefor} - B41J 2/17553: {Outer structure} - B41J 2202/08: dealing with thermal variations, e.g. cooling - B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS ## Abstract A liquid discharge head includes a plurality of pressure generating elements configured to generate pressure to discharge a liquid, a plurality of wirings configured to transmit a drive signal to the plurality of pressure generating elements, respectively, a plurality of integrated circuits configured to drive the plurality of pressure generating elements, respectively, the plurality of integrated circuits being provided on the plurality of wirings, respectively, and a heat sink configured to contact the plurality of integrated circuits to dissipate heat in the plurality of integrated circuits. The heat sink includes a first dissipation part that directly contacts one of the plurality of integrated circuits, and a second dissipating part that contacts another of the plurality of integrated circuits via one of the plurality of wirings. ## Claims ### Claim 1 A liquid discharge head, comprising: a plurality of pressure generating elements configured to generate pressure to discharge a liquid; a plurality of wirings configured to transmit a drive signal to the plurality of pressure generating elements, respectively; a plurality of integrated circuits including a first integrated circuit configured to drive a first pressure generating element of the plurality of pressure generating elements and a second integrated circuit configured to drive a second pressure generating element of the plurality of pressure generating elements, the plurality of integrated circuits being provided on the plurality of wirings, respectively; and a heat sink configured to contact the plurality of integrated circuits to dissipate heat in the plurality of integrated circuits, wherein the heat sink includes: a first dissipation part that directly contacts the first integrated circuit; and a second dissipation part that contacts the second integrated circuit via one of the plurality of wirings, and a thermal resistance of the first dissipation part is larger than a thermal resistance of the second dissipation part. ### Claim 2 (depends on 1) The liquid discharge head according to claim 1, wherein a length of the first dissipation part is longer than a length of the second dissipation part. ### Claim 3 (depends on 1) The liquid discharge head according to claim 1, wherein a thickness of the first dissipation part is thinner than a thickness of the second dissipation part. ### Claim 4 (depends on 1) The liquid discharge head according to claim 1, wherein the second dissipation part is disposed between the first dissipation part and a portion of the heat sink that contacts outside air. ### Claim 5 (depends on 4) The liquid discharge head according to claim 4, wherein the second dissipation part connects the first dissipation part and the portion of the heat sink that contacts outside air. ### Claim 6 (depends on 1) The liquid discharge head according to claim 1, wherein the heat sink includes: a first sandwiching member at which the heat sink is directly attached to a surface of one of the first integrated circuit; and a second sandwiching member at which the heat sink is attached to a surface of the second integrated circuit via the one of the plurality of wirings, and a thermal resistance of the first sandwiching member is larger than a thermal resistance of the second sandwiching member. ### Claim 7 (depends on 1) The liquid discharge head according to claim 1, wherein an area of the second dissipation part is larger than an area of the first dissipation part. ### Claim 8 (depends on 1) The liquid discharge head according to claim 1, wherein the heat sink includes: the first dissipation part contacting outside air; and the second dissipation part contacting outside air, and an area of the second dissipation part is larger than an area of the first dissipation part. ### Claim 9 (depends on 1) The liquid discharge head according to claim 1, wherein a width of the second dissipation part is longer than a width of the first dissipation part. ### Claim 10 (depends on 1) The liquid discharge head according to claim 1, wherein the heat sink includes a projection on a portion of the second dissipation part of the heat sink, and the portion is disposed outside the liquid discharge head to contact outside air. ### Claim 11 (depends on 1) A liquid discharge apparatus comprising the liquid discharge head according to claim 1. ### Claim 12 (depends on 1) The liquid discharge head of claim 1, wherein the second dissipation part contacts only the second integrated circuit via the one of the plurality of wirings. ### Claim 13 (depends on 1) The liquid discharge head of claim 1, wherein a material of the first dissipation part is different than a material of the second dissipation part. ### Claim 14 A liquid discharge head, comprising: a plurality of pressure generating elements configured to generate pressure to discharge a liquid; a plurality of wirings configured to transmit a drive signal to the plurality of pressure generating elements, respectively; a plurality of integrated circuits configured to drive the plurality of pressure generating elements, respectively, the plurality of integrated circuits being provided on the plurality of wirings, respectively; and a heat sink configured to contact the plurality of integrated circuits to dissipate heat in the plurality of integrated circuits, wherein the heat sink includes: a first dissipation part that directly contacts one of the plurality of integrated circuits; and a second dissipation part that contacts another of the plurality of integrated circuits via one of the plurality of wirings, and a thermal resistance of the first dissipation part s larger than a thermal resistance of the second dissipation part. ### Claim 15 A liquid discharge head, comprising: a plurality of pressure generating elements configured to generate pressure to discharge a liquid; a plurality of wirings configured to transmit a drive signal to the plurality of pressure generating elements, respectively; a plurality of integrated circuits including a first integrated circuit configured to drive a first pressure generating element of the plurality of pressure generating elements and a second integrated circuit configured to drive a second pressure generating element of the plurality of pressure generating elements, the plurality of integrated circuits being provided on the plurality of wirings, respectively; and a heat sink configured to contact the plurality of integrated circuits to dissipate heat in the plurality of integrated circuits, wherein the heat sink includes: a first dissipation part that directly contacts the first integrated circuit; and a second dissipation part that contacts the second integrated circuit via one of the plurality of wirings, a thermal resistance of the first dissipation part is different from a thermal resistance of the second dissipation part, and wherein a material of the first dissipation part is different than a material of the second dissipation part.