Patents by Inventor Yuka Yonekura
Yuka Yonekura has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 8966729Abstract: In sputter etching to improve the adhesion between upper electrodes and lead electrodes, the sputter etching of surfaces of the upper electrodes under an Ar gas flow at a flow rate of 60 sccm or more can reduce the residence time of Ar ions on the surfaces of the upper electrodes because of the Ar gas flow. This can prevent the charging of the upper electrodes due to the buildup of ionized Ar gas on the surfaces, reduce the influence of charging on piezoelectric elements, and provide a method for manufacturing a piezoelectric actuator that includes the piezoelectric elements each including a piezoelectric layer having small variations in hysteresis characteristics and deformation characteristics.Type: GrantFiled: March 3, 2011Date of Patent: March 3, 2015Assignee: Seiko Epson CorporationInventors: Hironobu Kazama, Takahiro Kamijo, Masato Shimada, Hiroyuki Kamei, Yuka Yonekura, Motoki Takabe
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Publication number: 20110219592Abstract: In sputter etching to improve the adhesion between upper electrodes and lead electrodes, the sputter etching of surfaces of the upper electrodes under an Ar gas flow at a flow rate of 60 sccm or more can reduce the residence time of Ar ions on the surfaces of the upper electrodes because of the Ar gas flow. This can prevent the charging of the upper electrodes due to the buildup of ionized Ar gas on the surfaces, reduce the influence of charging on piezoelectric elements, and provide a method for manufacturing a piezoelectric actuator that includes the piezoelectric elements each including a piezoelectric layer having small variations in hysteresis characteristics and deformation characteristics.Type: ApplicationFiled: March 3, 2011Publication date: September 15, 2011Applicant: SEIKO EPSON CORPORATIONInventors: Hironobu KAZAMA, Takahiro KAMIJO, Masato SHIMADA, Hiroyuki KAMEI, Yuka YONEKURA, Motoki TAKABE
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Patent number: 7918543Abstract: A liquid jet head includes a flow passage forming substrate formed of a crystal substrate provided with a pressure generating chamber communicating with nozzle openings, and a piezoelectric element including a lower electrode, a piezoelectric layer, and an upper electrode, which are provided on the flow passage forming substrate to change pressure in the pressure generating chamber. The piezoelectric layer has a thickness of 5 ?m or less and is formed of perovskite type crystals, and the distance between a diffraction peak position A of an X-ray derived from a surface (220) of the flow passage forming substrate and a diffraction peak position B of an X-ray derived from a surface (100) of the piezoelectric layer is within the range of 2?=25.487±0.1°.Type: GrantFiled: April 30, 2009Date of Patent: April 5, 2011Assignee: Seiko Epson CorporationInventors: Hironobu Kazama, Yuka Yonekura, Koji Sumi
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Patent number: 7896479Abstract: A liquid jet head has a channel-forming substrate composed of a crystal substrate having a pressure-generating chamber linked to a nozzle opening as well as a piezoelectric element composed of a lower electrode, a piezoelectric layer, and an upper electrode and formed on the channel-forming substrate so that the pressure in the pressure-generating chamber can be changed, with the piezoelectric layer having a thickness equal to or smaller than 5 ?m, made of a perovskite-type crystal, and formed so that the interval between the X-ray diffraction peak position derived from the (220) plane of the channel-forming substrate and the X-ray diffraction peak position derived from the (111) plane of the piezoelectric layer falls within the range 2?=9.059±0.1°.Type: GrantFiled: April 30, 2009Date of Patent: March 1, 2011Assignee: Seiko Epson CorporationInventors: Hironobu Kazama, Yuka Yonekura, Koji Sumi
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Patent number: 7896480Abstract: A liquid jet head includes a passage-forming substrate composed of a crystal substrate provided with pressure-generating chambers communicating with nozzle orifices and piezoelectric elements disposed on the passage-forming substrate and each composed of a lower electrode, a piezoelectric material layer, and an upper electrode to cause a change of pressure in the pressure-generating chamber. The piezoelectric material layer has a thickness of 5 ?m or less and is made of a perovskite-type crystal and is configured such that the distance between an X-ray diffraction peak position derived from the (220) plane of the passage-forming substrate and an X-ray diffraction peak position derived from the (110) plane of the piezoelectric material layer is within a range of 2?=16.262±0.1 degrees.Type: GrantFiled: April 30, 2009Date of Patent: March 1, 2011Assignee: Seiko Epson CorporationInventors: Hironobu Kazama, Yuka Yonekura, Koji Sumi
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Patent number: 7878631Abstract: A piezoelectric layer held between a first electrode on a substrate side and a second electrode formed on a surface of the piezoelectric layer facing away from the first electrode is formed of a ferroelectric material with a perovskite crystal structure, and the ratio of the surface roughness of the piezoelectric layer to the surface roughness of the first electrode falls within the range of 0.58 to 1.60.Type: GrantFiled: March 20, 2009Date of Patent: February 1, 2011Assignee: Seiko Epson CorporationInventors: Akira Kuriki, Yuka Yonekura
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Publication number: 20090273654Abstract: A liquid jet head includes a flow passage forming substrate formed of a crystal substrate provided with a pressure generating chamber communicating with nozzle openings, and a piezoelectric element including a lower electrode, a piezoelectric layer, and an upper electrode, which are provided on the flow passage forming substrate to change pressure in the pressure generating chamber. The piezoelectric layer has a thickness of 5 ?m or less and is formed of perovskite type crystals, and the distance between a diffraction peak position A of an X-ray derived from a surface (220) of the flow passage forming substrate and a diffraction peak position B of an X-ray derived from a surface (100) of the piezoelectric layer is within the range of 2?=25.487±0.1°.Type: ApplicationFiled: April 30, 2009Publication date: November 5, 2009Applicant: SEIKO EPSON CORPORATIONInventors: Hironobu KAZAMA, Yuka YONEKURA, Koji SUMI
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Publication number: 20090273651Abstract: A liquid jet head has a channel-forming substrate composed of a crystal substrate having a pressure-generating chamber linked to a nozzle opening as well as a piezoelectric element composed of a lower electrode, a piezoelectric layer, and an upper electrode and formed on the channel-forming substrate so that the pressure in the pressure-generating chamber can be changed, with the piezoelectric layer having a thickness equal to or smaller than 5 ?m, made of a perovskite-type crystal, and formed so that the interval between the X-ray diffraction peak position derived from the (220) plane of the channel-forming substrate and the X-ray diffraction peak position derived from the (111) plane of the piezoelectric layer falls within the range 2?=9.059±0.1°.Type: ApplicationFiled: April 30, 2009Publication date: November 5, 2009Applicant: SEIKO EPSON CORPORATIONInventors: Hironobu KAZAMA, Yuka YONEKURA, Koji SUMI
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Publication number: 20090273652Abstract: A liquid jet head includes a passage-forming substrate composed of a crystal substrate provided with pressure-generating chambers communicating with nozzle orifices and piezoelectric elements disposed on the passage-forming substrate and each composed of a lower electrode, a piezoelectric material layer, and an upper electrode to cause a change of pressure in the pressure-generating chamber. The piezoelectric material layer has a thickness of 5 ?m or less and is made of a perovskite-type crystal and is configured such that the distance between an X-ray diffraction peak position derived from the (220) plane of the passage-forming substrate and an X-ray diffraction peak position derived from the (110) plane of the piezoelectric material layer is within a range of 2?=16.262±0.1 degrees.Type: ApplicationFiled: April 30, 2009Publication date: November 5, 2009Applicant: SEIKO EPSON CORPORATIONInventors: Hironobu KAZAMA, Yuka YONEKURA, Koji SUMI
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Publication number: 20090237465Abstract: A piezoelectric layer held between a first electrode on a substrate side and a second electrode formed on a surface of the piezoelectric layer facing away from the first electrode is formed of a ferroelectric material with a perovskite crystal structure, and the ratio of the surface roughness of the piezoelectric layer to the surface roughness of the first electrode falls within the range of 0.58 to 1.60.Type: ApplicationFiled: March 20, 2009Publication date: September 24, 2009Applicant: SEIKO EPSON CORPORATIONInventors: Akira Kuriki, Yuka Yonekura