Patents by Inventor Junichiro Shimizu
Junichiro Shimizu 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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Publication number: 20190165541Abstract: A laser element and a modulator element respectively include first and second mesa portions provided to be connected above a substrate. The first and second mesa portions are formed using individual mask films (dielectric masks). In the first mesa portion, a p-type first clad layer not containing Al as the uppermost layer thereof covers the upper surface and each of the side surfaces of a multi-layer body (including an n-type optical guide layer, an active layer, a p-type optical guide layer, and a p-type semiconductor layer). In the first mesa portion, the multi-layer body including the semiconductor layers containing Al is covered with the p-type first clad layer not containing Al. This can prevent unneeded aluminum oxide from being generated and improve the crystallinities of the constituent layers of the second mesa portion. It is possible to maintain excellent optical coupling between the first and second mesa portions.Type: ApplicationFiled: October 3, 2018Publication date: May 30, 2019Inventors: Isao WATANABE, Masahide KOBAYASHI, Junichiro SHIMIZU
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Patent number: 9007722Abstract: To uniformly determine the positional relationship between a main magnetic pole and a spin torque oscillator while independently optimizing the main magnetic pole and the spin torque oscillator. On a trailing end surface of a main magnetic pole, a step is provided at the boundary between the main magnetic pole and a gap material disposed on both sides thereof, and a spin torque oscillator is formed on the step. The spin torque oscillator is effectively separated into two regions by utilizing the step. Further, a part of the spin torque oscillator is removed so as to disable the unwanted region, thereby realizing a self-alignment type high frequency magnetic field assisted magnetic recording head structure such that the positions of the end portions of the main magnetic pole and the spin torque oscillator are aligned.Type: GrantFiled: August 16, 2013Date of Patent: April 14, 2015Assignee: Hitachi, Ltd.Inventors: Junichiro Shimizu, Kikuo Kusukawa, Yo Sato, Masukazu Igarashi
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Patent number: 9001465Abstract: Embodiments of the present invention generally relate to a MAMR head. The MAMR head includes an STO. The STO has a first surface at a media facing surface, a second surface that is opposite the first surface and a third surface adjacent to the first and second surfaces. The first and third surfaces form a first acute angle and the second and third surfaces form a second acute angle, where the second acute angle is less than or equal to the first acute angle. Having this configuration, the electrical current going through the STO is substantially perpendicular to the STO, which causes the spin torque to be maximized.Type: GrantFiled: April 16, 2014Date of Patent: April 7, 2015Assignee: HGST Netherlands B.V.Inventors: Junichiro Shimizu, Masukaza Igarashi
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Patent number: 8917481Abstract: Provided are a structure of a high frequency magnetic field assisted magnetic recording head in which the positional relationship of a main magnetic pole and a spin torque oscillator in a cross-track direction is accurately determined, and in which variations are not caused in high frequency magnetic field assist characteristics, and a method of manufacturing the structure. The high frequency magnetic field assisted magnetic recording head includes a main magnetic pole, a spin torque oscillator disposed on the main magnetic pole, and an insulating side gap covering a side surface of the main magnetic pole and a side surface of the spin torque oscillator. The main magnetic pole and the spin torque oscillator are formed between both side surfaces of the side gap. Thus, a self-alignment structure of the high frequency magnetic field assisted magnetic recording head is obtained.Type: GrantFiled: April 17, 2014Date of Patent: December 23, 2014Assignee: Hitachi, Ltd.Inventors: Kikuo Kusukawa, Junichiro Shimizu, Katsuro Watanabe
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Publication number: 20140313616Abstract: Provided are a structure of a high frequency magnetic field assisted magnetic recording head in which the positional relationship of a main magnetic pole and a spin torque oscillator in a cross-track direction is accurately determined, and in which variations are not caused in high frequency magnetic field assist characteristics, and a method of manufacturing the structure. The high frequency magnetic field assisted magnetic recording head includes a main magnetic pole, a spin torque oscillator disposed on the main magnetic pole, and an insulating side gap covering a side surface of the main magnetic pole and a side surface of the spin torque oscillator. The main magnetic pole and the spin torque oscillator are formed between both side surfaces of the side gap. Thus, a self-alignment structure of the high frequency magnetic field assisted magnetic recording head is obtained.Type: ApplicationFiled: April 17, 2014Publication date: October 23, 2014Applicant: Hitachi, Ltd.Inventors: Kikuo KUSUKAWA, Junichiro SHIMIZU, Katsuro WATANABE
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Publication number: 20140063658Abstract: To uniformly determine the positional relationship between a main magnetic pole and a spin torque oscillator while independently optimizing the main magnetic pole and the spin torque oscillator. On a trailing end surface of a main magnetic pole, a step is provided at the boundary between the main magnetic pole and a gap material disposed on both sides thereof, and a spin torque oscillator is formed on the step. The spin torque oscillator is effectively separated into two regions by utilizing the step. Further, a part of the spin torque oscillator is removed so as to disable the unwanted region, thereby realizing a self-alignment type high frequency magnetic field assisted magnetic recording head structure such that the positions of the end portions of the main magnetic pole and the spin torque oscillator are aligned.Type: ApplicationFiled: August 16, 2013Publication date: March 6, 2014Applicant: HITACHI, LTD.Inventors: Junichiro SHIMIZU, Kikuo KUSUKAWA, Yo SATO, Masukazu IGARASHI
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Patent number: 8547804Abstract: In a magnetic recording head including an optical waveguide for guiding a laser beam to a surface of a magnetic recording medium, a shield is provided in the vicinity of at least one portion changing discontinuously in structure of the optical waveguide to absorb or reflect non-propagating light leaking from the discontinuous portion to the outside of the optical waveguide.Type: GrantFiled: August 24, 2011Date of Patent: October 1, 2013Assignee: Hitachi, Ltd.Inventor: Junichiro Shimizu
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Patent number: 8477570Abstract: A slider including a magnetic head part, an optical waveguide, and a near field element is fixed by first and second adhesives to a submount on which a semiconductor laser and a mirror are mounted, the mirror being placed at one end of the semiconductor laser in a resonance direction thereof and reflecting a laser in a direction intersecting with the resonance direction. At this time, at least parts of the first and second adhesives are applied to a position opposed to the semiconductor laser with an intermediation of the submount. The first adhesive having a higher Young's modulus than that of the second adhesive is applied onto an inflow end side of the slider including a solder connection portion, the second adhesive being applied onto an outflow end side of the slider.Type: GrantFiled: November 30, 2009Date of Patent: July 2, 2013Assignee: Hitachi, Ltd.Inventors: Satoshi Arai, Irizo Naniwa, Junichiro Shimizu, Takuya Matsumoto, Shigeyuki Sasaki
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Patent number: 8406093Abstract: Provided is a thermal-assisted-magnetic-recording head capable of directing, to a magnetic recording medium, light in which the spot size is reduced to submicron order with high total optical propagation efficiency. A light coupling unit that guides light emitted from the light source into a magnetic head and a high-refractive-index core that couples with the light guided by the light coupling unit to lead the light to an air bearing surface are arranged in the magnetic head. The light coupling unit includes a plurality of thin-film-like cores that are separated from each other by a clad material. An upper part of the high-refractive-index core is placed between two thin-film-like cores.Type: GrantFiled: October 13, 2010Date of Patent: March 26, 2013Assignee: Hitachi, Ltd.Inventors: Yasuhiko Iwanabe, Takuya Matsumoto, Junichiro Shimizu, Harukazu Miyamoto
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Publication number: 20120320719Abstract: A slider including a magnetic head part, an optical waveguide, and a near field element is fixed by first and second adhesives to a submount on which a semiconductor laser and a mirror are mounted, the mirror being placed at one end of the semiconductor laser in a resonance direction thereof and reflecting a laser in a direction intersecting with the resonance direction. At this time, at least parts of the first and second adhesives are applied to a position opposed to the semiconductor laser with an intermediation of the submount. The first adhesive having a higher Young's modulus than that of the second adhesive is applied onto an inflow end side of the slider including a solder connection portion, the second adhesive being applied onto an outflow end side of the slider.Type: ApplicationFiled: November 30, 2009Publication date: December 20, 2012Inventors: Satoshi Arai, Irizo Naniwa, Junichiro Shimizu, Takuya Matsumoto, Shigeyuki Sasaki
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Patent number: 8300503Abstract: In a thermally assisted magnetic recording head having a light source and a waveguide to lead a laser beam radiated from the light source to a front end of the magnetic head, while blocking an adverse effect of heat generated in the light source and securing a good floating characteristic, the light source and the magnetic head are optically coupled with high efficiency and the magnetic head itself is reduced in size. This invention provides a reflection mirror that is formed of a part or whole of one inclined end surface of the semiconductor laser mounted on the first submount. Near one end surface of the slider is provided the optical waveguide that pierces through the slider in a direction of the thickness thereof.Type: GrantFiled: June 3, 2009Date of Patent: October 30, 2012Assignee: Hitachi, Ltd.Inventors: Satoshi Arai, Naoki Matsushima, Irizo Naniwa, Junichiro Shimizu
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Patent number: 8270262Abstract: In a thermally assisted magnetic recording head (10A), a sub-mount (8A) on which a laser diode is mounted is arranged between an HGA (41) and a magnetic head slider (9). The sub-mount has a wiring line (81) which electrically connects a terminal (91) arranged on the magnetic head slider (9) and a terminal (411) arranged on the HGA (41).Type: GrantFiled: June 1, 2009Date of Patent: September 18, 2012Assignee: Hitachi, Ltd.Inventors: Irizo Naniwa, Takuya Matsumoto, Satoshi Arai, Junichiro Shimizu
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Publication number: 20120051195Abstract: In a magnetic recording head including an optical waveguide for guiding a laser beam to a surface of a magnetic recording medium, a shield is provided in the vicinity of at least one portion changing discontinuously in structure of the optical waveguide to absorb or reflect non-propagating light leaking from the discontinuous portion to the outside of the optical waveguide.Type: ApplicationFiled: August 24, 2011Publication date: March 1, 2012Applicant: HITACHI, LTD.Inventor: Junichiro SHIMIZU
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Patent number: 8054571Abstract: A thermally assisted magnetic recording head includes a flying slider, a magnetic field generation device mounted on the flying slider, a first waveguide disposed near the magnetic field generation device for guiding incident light from a top surface of the flying slider on a side of the flying slider toward an air bearing bottom surface of the flying slider, an optical near-field generator disposed at an emission end of the first waveguide, a second waveguide which is separate from the first waveguide and which is spaced from and coupled to the first waveguide at a distance of no greater than a light wavelength, and a first optical detector for detecting the intensity of light propagating in the second waveguide. The first waveguide and the second waveguide are disposed so as to extend in a direction substantially perpendicular to the air bearing bottom surface of the flying slider.Type: GrantFiled: October 26, 2010Date of Patent: November 8, 2011Assignee: Hitachi, Ltd.Inventors: Takuya Matsumoto, Junichiro Shimizu
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Publication number: 20110149698Abstract: In a thermally assisted magnetic recording head (10A), a sub-mount (8A) on which a laser diode is mounted is arranged between an HGA (41) and a magnetic head slider (9). The sub-mount has a wiring line (81) which electrically connects a terminal (91) arranged on the magnetic head slider (9) and a terminal (411) arranged on the HGA (41).Type: ApplicationFiled: June 1, 2009Publication date: June 23, 2011Applicant: HITACHI, LTD.Inventors: Irizo Naniwa, Takuya Matsumoto, Satoshi Arai, Junichiro Shimizu
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Publication number: 20110141862Abstract: In a thermally assisted magnetic recording head having a light source and a waveguide to lead a laser beam radiated from the light source to a front end of the magnetic head, while blocking an adverse effect of heat generated in the light source and securing a good floating characteristic, the light source and the magnetic head are optically coupled with high efficiency and the magnetic head itself is reduced in size. This invention provides a reflection mirror that is formed of a part or whole of one inclined end surface of the semiconductor laser mounted on the first submount. Near one end surface of the slider is provided the optical waveguide that pierces through the slider in a direction of the thickness thereof.Type: ApplicationFiled: June 3, 2009Publication date: June 16, 2011Applicant: Hitachi, Ltd.Inventors: Satoshi Arai, Naoki Matsushima, Irizo Naniwa, Junichiro Shimizu
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Publication number: 20110090770Abstract: Provided is a thermal-assisted-magnetic-recording head capable of directing, to a magnetic recording medium, light in which the spot size is reduced to submicron order with high total optical propagation efficiency. A light coupling unit that guides light emitted from the light source into a magnetic head and a high-refractive-index core that couples with the light guided by the light coupling unit to lead the light to an air bearing surface are arranged in the magnetic head. The light coupling unit includes a plurality of thin-film-like cores that are separated from each other by a clad material. An upper part of the high-refractive-index core is placed between two thin-film-like cores.Type: ApplicationFiled: October 13, 2010Publication date: April 21, 2011Inventors: Yasuhiko IWANABE, Takuya Matsumoto, Junichiro Shimizu, Harukazu Miyamoto
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Patent number: 7921436Abstract: An optical device integrated head having high light utilizing efficiency by decreasing the propagation loss caused from an optical source to a recording medium, conducting by mounting according to compact active alignment method for efficiently guiding a light generated from a laser device to the top end of a head, in which a light source device mounted on a submount has a mirror portion having an inclinated surface to at least a portion of one edge thereof for reflecting an output light from the optical source device at the inclinated surface, a structural member including a lens structure for further allowing a light to pass through the submount, and an optical waveguide disposed passing through a slider for mounting the submount, and the optical source and the slider are positioned by using active alignment of light in a chip-on carrier structure having the optical source device mounted on the submount.Type: GrantFiled: February 14, 2008Date of Patent: April 5, 2011Assignee: Hitachi, Ltd.Inventors: Junichiro Shimizu, Masato Shishikura
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Patent number: 7898759Abstract: A second waveguide is formed near a first waveguide for guiding light to the vicinity of a main pole of a thermally assisted magnetic recording head, and a portion of light propagated through the waveguide 1 is branched to the second waveguide. The light transmitting in the second waveguide is detected by a photodetector to detect an intensity of the light propagated through the first waveguide. In the magnetic recording apparatus, an intensity of a semiconductor laser is decreased when an amount of light incident to the photodetector is large and the intensity of the semiconductor laser is increased when the amount of light incident to the photodetector is small. By constituting a feedback loop as described above, the intensity of the light propagated through the first waveguide is kept constant.Type: GrantFiled: January 17, 2008Date of Patent: March 1, 2011Assignee: Hitachi, Ltd.Inventors: Takuya Matsumoto, Junichiro Shimizu
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Publication number: 20110038235Abstract: A thermally assisted magnetic recording head includes a flying slider, a magnetic field generation device mounted on the flying slider, a first waveguide disposed near the magnetic field generation device for guiding incident light from a top surface of the flying slider on a side of the flying slider toward an air bearing bottom surface of the flying slider, an optical near-field generator disposed at an emission end of the first waveguide, a second waveguide which is separate from the first waveguide and which is spaced from and coupled to the first waveguide at a distance of no greater than a light wavelength, and a first optical detector for detecting the intensity of light propagating in the second waveguide. The first waveguide and the second waveguide are disposed so as to extend in a direction substantially perpendicular to the air bearing bottom surface of the flying slider.Type: ApplicationFiled: October 26, 2010Publication date: February 17, 2011Inventors: Takuya Matsumoto, Junichiro Shimizu