# US 2013/0155134 A1 · Liquid ejecting apparatus and liquid ejecting method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0155134 A1 - Document ID: US20130155134A1 - Status: Published application - Kind: A1 - Application number: 13/732,186 - Filed: 2012-12-31 - Published: 2013-06-20 - Earliest claimed: 2008-11-05 - Assignees: Seiko Epson Corporation - Inventors: Kinya OZAWA - Web page: https://patentgrep.com/patent/US20130155134A1 ## CPC - B41J 2/04588: {using a specific waveform} - B41J 2/04581: {controlling heads based on piezoelectric elements} - B41J 2/14274: {of stacked structure type, deformed by compression/extension and disposed on a diaphragm} - B41J 29/38: Drives, motors, controls or automatic cut-off devices for the entire printing mechanism - B41J 2202/11: characterised by specific geometrical characteristics - B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS ## Abstract A liquid ejecting apparatus includes: a pressure chamber that communicates with a liquid supply section and a nozzle; an element that changes a pressure of liquid within the pressure chamber; and an ejection pulse generation section that generates an ejection pulse for operating the element to eject the liquid from the nozzle. The viscosity of the liquid is not less than 8 millipascal seconds. The nozzle has a first portion in which a liquid ejection side thereof has a smaller opening area than a pressure chamber side thereof, and a second portion which communicates with an ejection side end portion of the first portion. The ejection pulse has a depressurizing portion for depressurizing the liquid to attract a meniscus positioned on the second portion to the first portion, and a pressurizing portion for pressurizing the liquid to eject the liquid before the meniscus returns to the second portion. ## Claims ### Claim 1 A liquid ejecting apparatus comprising: a pressure chamber that communicates with a liquid supply section and a nozzle; an element that changes a pressure of liquid within the pressure chamber; and an ejection pulse generation section that generates an ejection pulse for operating the element in order to eject the liquid from the nozzle; wherein a viscosity of the liquid is not less than 8 millipascal seconds; wherein the nozzle comprises: a first, tapered portion comprising a first, smaller cross-sectional area at a first, liquid ejection end and a second, larger cross-sectional area at a second, pressure chamber end; and a second portion which communicates with the first end of the first portion, comprising a length in a liquid ejection direction and a width in a cross-sectional direction, wherein the length is smaller than the width; and wherein the ejection pulse comprises: a depressurizing portion for depressurizing the liquid in order to attract a meniscus positioned on the second portion to the first portion, and a pressurizing portion for pressurizing the liquid in order to eject the liquid before the meniscus attracted to the first portion returns to the second portion. ### Claim 2 (depends on 1) The liquid ejecting apparatus according to claim 1, wherein the ejection pulse further comprises a maintaining portion for maintaining a state of the element at the time of stopping the generation of the depressurizing portion during the time period from the time of stopping the generation of the depressurizing portion to the time of starting the application of the pressurizing portion. ### Claim 3 (depends on 1) The liquid ejecting apparatus according to claim 1, wherein an impedance of the nozzle is smaller than an impedance of the liquid supply section. ### Claim 4 (depends on 1) The liquid ejecting apparatus according to claim 1, wherein the first portion of the nozzle comprises a substantially frustoconical shape comprising a taper angle of 40 degrees or more. ### Claim 5 (depends on 1) The liquid ejecting apparatus according to claim 1, wherein the second portion of the nozzle comprises a substantially constant cross-sectional area along the liquid ejection direction. ### Claim 6 (depends on 1) The liquid ejecting apparatus according to claim 1, wherein the element is a piezoelectric element which is deformed in accordance with an electric potential of the applied ejection pulse so as to change a volume of the pressure chamber and thereby change the pressure of the liquid. ### Claim 7 (depends on 6) The liquid ejecting apparatus according to claim 6, wherein the ejection pulse is such that a volume variation of the pressure chamber per unit time caused by the pressurizing portion is larger than a volume variation of the pressure chamber per unit time caused by the depressurizing portion, and wherein the ejection pulse does not have a section, which is subsequent to the pressurizing portion, for suppressing movement of the meniscus after the ejection of the liquid. ### Claim 8 A liquid ejecting method for ejecting liquid comprising a viscosity of 8 millipascal seconds or more, from a nozzle by using a liquid ejecting apparatus comprising: a pressure chamber, which communicates with a liquid supply section; the nozzle, which communicates with the pressure chamber and comprises a first, tapered portion comprising a first, smaller cross-sectional area at a first, liquid ejection end and a second, larger cross-sectional area at a second, pressure chamber end; and a second portion which communicates with the first end of the first portion, comprising a length in a liquid ejection direction and a width in a cross-sectional direction, wherein the length is smaller than the width; and an element, which changes a pressure of liquid within the pressure chamber, the liquid ejecting method comprising: depressurizing the liquid in order to attract a meniscus positioned on the second portion to the first portion; and pressurizing the liquid in order to eject the liquid before the meniscus attracted to the first portion returns to the second portion.