Patents by Inventor Katsuhiko Yasuda
Katsuhiko Yasuda 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: 7652970Abstract: An optical information apparatus includes a laser which emits a light beam, an objective lens and the like which converge a light beam emitted from the laser on an optical recording medium, spherical aberration correction instrument which is arranged on an optical axis of the light beam which links the laser and the objective lens, and corrects a spherical aberration generated on the optical recording medium. Correction is performed so that outgoing power of the laser changes according to a correction amount by the spherical aberration correction instrument.Type: GrantFiled: June 20, 2005Date of Patent: January 26, 2010Assignee: Panasonic CorporationInventors: Katsuhiko Yasuda, Hidenori Wada, Takeharu Yamamoto, Toshio Matsumoto
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Patent number: 7558162Abstract: An optical information apparatus of the present invention includes: an optical pick-up head including: a light source; a diffraction unit; a condensing unit; a beam splitter; a photodetector; and a tracking error signal generator. An optical recording medium has tracks arranged substantially at a constant pitch. An average of a pitch is tp. When a main beam is placed on the track, a first sub-beam and a second sub-beam are placed between the tracks.Type: GrantFiled: October 31, 2007Date of Patent: July 7, 2009Assignee: Panasonic CorporationInventors: Shin-ichi Kadowaki, Kousei Sano, Akihiro Arai, Katsuhiko Yasuda, Tomotada Kamei, Hiroaki Yamamoto, Fumitomo Yamasaki
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Patent number: 7558170Abstract: An optical information apparatus of the present invention includes: an optical pick-up head including: a light source; a diffraction unit; a condensing unit; a beam splitter; a photodetector; and a tracking error signal generator. An optical recording medium has tracks arranged substantially at a constant pitch. An average of a pitch is tp. When a main beam is placed on the track, a first sub-beam and a second sub-beam are placed between the tracks.Type: GrantFiled: October 31, 2007Date of Patent: July 7, 2009Assignee: Panasonic CorporationInventors: Shin-ichi Kadowaki, Kousei Sano, Akihiro Arai, Katsuhiko Yasuda, Tomotada Kamei, Hiroaki Yamamoto, Fumitomo Yamasaki
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Patent number: 7542382Abstract: An optical information apparatus of the present invention includes: an optical pick-up head including: a light source; a diffraction unit; a condensing unit; a beam splitter; a photodetector; and a tracking error signal generator. An optical recording medium has tracks arranged substantially at a constant pitch. An average of a pitch is tp. When a main beam is placed on the track, a first sub-beam and a second sub-beam are placed between the tracks.Type: GrantFiled: October 31, 2007Date of Patent: June 2, 2009Assignee: Panasonic CorporationInventors: Shin-ichi Kadowaki, Kousei Sano, Akihiro Arai, Katsuhiko Yasuda, Tomotada Kamei, Hiroaki Yamamoto, Fumitomo Yamasaki
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Patent number: 7539090Abstract: An optical information apparatus of the present invention includes: an optical pick-up head including: a light source; a diffraction unit; a condensing unit; a beam splitter; a photodetector; and a tracking error signal generator. An optical recording medium has tracks arranged substantially at a constant pitch. An average of a pitch is tp. When a main beam is placed on the track, a first sub-beam and a second sub-beam are placed between the tracks.Type: GrantFiled: October 31, 2007Date of Patent: May 26, 2009Assignee: Panasonic CorporationInventors: Shin-ichi Kadowaki, Kousei Sano, Akihiro Arai, Katsuhiko Yasuda, Tomotada Kamei, Hiroaki Yamamoto, Fumitomo Yamasaki
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Patent number: 7463561Abstract: An optical information apparatus of the present invention includes: an optical pick-up head including: a light source; a diffraction unit; a condensing unit; a beam splitter; a photodetector; and a tracking error signal generator. An optical recording medium has tracks arranged substantially at a constant pitch. An average of a pitch is tp. When a main beam is placed on the track, a first sub-beam and a second sub-beam are placed between the tracks.Type: GrantFiled: April 23, 2007Date of Patent: December 9, 2008Assignee: Panasonic CorporationInventors: Shin-ichi Kadowaki, Kousei Sano, Akihiro Arai, Katsuhiko Yasuda, Tomotada Kamei, Hiroaki Yamamoto, Fumitomo Yamasaki
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Patent number: 7460448Abstract: An optical information apparatus of the present invention includes: an optical pick-up head including: a light source; a diffraction unit; a condensing unit; a beam splitter; a photodetector; and a tracking error signal generator. An optical recording medium has tracks arranged substantially at a constant pitch. An average of a pitch is tp. When a main beam is placed on the track, a first sub-beam and a second sub-beam are placed between the tracks.Type: GrantFiled: April 23, 2007Date of Patent: December 2, 2008Assignee: Panasonic CorporationInventors: Shin-ichi Kadowaki, Kousei Sano, Akihiro Arai, Katsuhiko Yasuda, Tomotada Kamei, Hiroaki Yamamoto, Fumitomo Yamasaki
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Publication number: 20080259750Abstract: An optical information apparatus of the present invention includes: an optical pick-up head including: a light source; a diffraction unit; a condensing unit; a beam splitter; a photodetector; and a tracking error signal generator. An optical recording medium has tracks arranged substantially at a constant pitch. An average of a pitch is tp. When a main beam is placed on the track, a first sub-beam and a second sub-beam are placed between the tracks.Type: ApplicationFiled: October 31, 2007Publication date: October 23, 2008Applicant: Matsushita Electric Industrial Co., Ltd.Inventors: Shin-ichi Kadowaki, Kousei Sano, Akihiro Arai, Katsuhiko Yasuda, Tomotada Kamei, Hiroaki Yamamoto, Fumitomo Yamasaki
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Publication number: 20080089195Abstract: An optical information apparatus of the present invention includes: an optical pick-up head including: a light source; a diffraction unit; a condensing unit; a beam splitter; a photodetector; and a tracking error signal generator. An optical recording medium has tracks arranged substantially at a constant pitch. An average of a pitch is tp. When a main beam is placed on the track, a first sub-beam and a second sub-beam are placed between the tracks.Type: ApplicationFiled: October 31, 2007Publication date: April 17, 2008Applicant: Matsushita Electric Industrial Co., Ltd.Inventors: Shin-ichi Kadowaki, Kousei Sano, Akihiro Arai, Katsuhiko Yasuda, Tomotada Kamei, Hiroaki Yamamoto, Fumitomo Yamasaki
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Publication number: 20080084798Abstract: An optical information apparatus of the present invention includes: an optical pick-up head including: a light source; a diffraction unit; a condensing unit; a beam splitter; a photodetector; and a tracking error signal generator. An optical recording medium has tracks arranged substantially at a constant pitch. An average of a pitch is tp. When a main beam is placed on the track, a first sub-beam and a second sub-beam are placed between the tracks.Type: ApplicationFiled: October 31, 2007Publication date: April 10, 2008Applicant: Matsushita Electric Industrial Co., Ltd.Inventors: Shin-ichi Kadowaki, Kousei Sano, Akihiro Arai, Katsuhiko Yasuda, Tomotada Kamei, Hiroaki Yamamoto, Fumitomo Yamasaki
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Publication number: 20080068944Abstract: An optical information apparatus of the present invention includes: an optical pick-up head including: a light source; a diffraction unit; a condensing unit; a beam splitter; a photodetector; and a tracking error signal generator. An optical recording medium has tracks arranged substantially at a constant pitch. An average of a pitch is tp. When a main beam is placed on the track, a first sub-beam and a second sub-beam are placed between the tracks.Type: ApplicationFiled: October 31, 2007Publication date: March 20, 2008Applicant: Matsushita Electric Industrial Co., Ltd.Inventors: Shin-ichi Kadowaki, Kousei Sano, Akihiro Arai, Katsuhiko Yasuda, Tomotada Kamei, Hiroaki Yamamoto, Fumitomo Yamasaki
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Publication number: 20070253068Abstract: When a spherical aberration generated on an optical recording medium is optically corrected, there has been a problem of irradiation power change of an output on an objective lens side due to a change of a signal level detected by a light quantity detector in response to the correction value.Type: ApplicationFiled: June 20, 2005Publication date: November 1, 2007Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.Inventors: Katsuhiko Yasuda, Hidenori Wada, Takeharu Yamamoto, Toshio Matsumoto
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Publication number: 20070195664Abstract: An optical information apparatus of the present invention includes: an optical pick-up head including: a light source; a diffraction unit; a condensing unit; a beam splitter; a photodetector; and a tracking error signal generator. An optical recording medium has tracks arranged substantially at a constant pitch. An average of a pitch is tp. When a main beam is placed on the track, a first sub-beam and a second sub-beam are placed between the tracks.Type: ApplicationFiled: April 23, 2007Publication date: August 23, 2007Applicant: Matsushita Electric Industrial Co., Ltd.Inventors: Shin-ichi Kadowaki, Kousei Sano, Akihiro Arai, Katsuhiko Yasuda, Tomotada Kamei, Hiroaki Yamamoto, Fumitomo Yamasaki
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Publication number: 20070195663Abstract: An optical information apparatus of the present invention includes: an optical pick-up head including: a light source; a diffraction unit; a condensing unit; a beam splitter; a photodetector; and a tracking error signal generator. An optical recording medium has tracks arranged substantially at a constant pitch. An average of a pitch is tap. When a main beam is placed on the track, a first sub-beam and a second sub-beam are placed between the tracks.Type: ApplicationFiled: April 23, 2007Publication date: August 23, 2007Applicant: Matsushita Electric Industrial Co., Ltd.Inventors: Shin-ichi Kadowaki, Kousei Sano, Akihiro Arai, Katsuhiko Yasuda, Tomotada Kamei, Hiroaki Yamamoto, Fumitomo Yamasaki
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Patent number: 7227819Abstract: An optical information apparatus of the present invention includes: an optical pick-up head including: a light source; a diffraction unit; a condensing unit; a beam splitter; a photodetector; and a tracking error signal generator. An optical recording medium has tracks arranged substantially at a constant pitch. An average of a pitch is tp. When a main beam is placed on the track, a first sub-beam and a second sub-beam are placed between the tracks.Type: GrantFiled: August 22, 2003Date of Patent: June 5, 2007Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Shin-ichi Kadowaki, Kousei Sano, Akihiro Arai, Katsuhiko Yasuda, Tomotada Kamei, Hiroaki Yamamoto, Fumitomo Yamasaki
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Patent number: 7065013Abstract: The quantity of spherical aberration correction is predetermined for each recording plane of an optical disk on which focusing control is performed. Before operating the focusing control, the quantity of spherical aberration to be corrected by an aberration correcting system is set based on an output signal from an aberration correction quantity switching device that corresponds to the type of the optical disk and the recording plane to be subjected to the focusing control. This makes it possible to perform stable focusing control on each recording plane of a multi-layer optical disk with high density by using an objecting lens having a large NA after spherical aberration has been corrected properly.Type: GrantFiled: July 1, 2005Date of Patent: June 20, 2006Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Katsuhiko Yasuda, Kousei Sano, Daisuke Ogata, Yuuichi Kuze
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Patent number: 7031247Abstract: Tilt which is inclination of a normal of optical disk relative to optical axis of optical head is corrected with a liquid crystal element. In a driver for the liquid crystal element, a periodic waveform generator generates periodic waveform and an inverting element inverts the periodic waveform. The periodic waveform and the inverted waveform are connected to two ends of a potential divider which provides partial voltages. The periodic waveform is connected to a common electrode of the liquid crystal element, and the partial voltages of the potential divider are connected to electrodes opposing the common electrode. A structure of a driver circuit for each direction is simple. Tilt in a plurality of directions can be performed independently of each other. Spherical aberration is also corrected. When the liquid crystal element is mounted to a fixed component, deterioration due to jitters is reduced.Type: GrantFiled: September 24, 2003Date of Patent: April 18, 2006Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Katsuhiko Yasuda, Hidenori Wada, Daisuke Ogata, Kanji Wakabayashi, Naoya Hotta
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Publication number: 20050265144Abstract: The quantity of spherical aberration correction is predetermined for each recording plane of an optical disk on which focusing control is performed. Before operating the focusing control, the quantity of spherical aberration to be corrected by an aberration correcting system is set based on an output signal from an aberration correction quantity switching device that corresponds to the type of the optical disk and the recording plane to be subjected to the focusing control. This makes it possible to perform stable focusing control on each recording plane of a multi-layer optical disk with high density by using an objecting lens having a large NA after spherical aberration has been corrected properly.Type: ApplicationFiled: July 1, 2005Publication date: December 1, 2005Applicant: Matsushita Electric Industrial Co., Ltd.Inventors: Katsuhiko Yasuda, Kousei Sano, Daisuke Ogata, Yuuichi Kuze
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Patent number: 6967916Abstract: An optical head apparatus capable of stably obtaining a detection signal of spherical aberration even with a high density optical disk. A spherical aberration error signal is obtained by: dividing the returning light from the optical disk into a transmitted light and a diffracted light; reproducing information with the transmitted light having a larger amount of light while dividing the diffracted light having a small amount of light into two regions, i.e., region near the optical axis and a region distant from the optical axis; determining amounts of focus deviation in respective regions as focus error signals; and taking the difference signal therebetween. Thus, it is possible to detect the amount of spherical aberration with the SN ratio of the information reproducing signal kept at high level.Type: GrantFiled: October 10, 2001Date of Patent: November 22, 2005Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Kousei Sano, Shin-ichi Kadowaki, Yoshiaki Komma, Seiji Nishino, Katsuhiko Yasuda, Akihiro Yasuda
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Publication number: 20050199778Abstract: An optical information apparatus of the present invention includes: an optical pick-up head including: a light source; a diffraction unit; a condensing unit; a beam splitter; a photodetector; and a tracking error signal generator. An optical recording medium has tracks arranged substantially at a constant pitch. An average of a pitch is tp. When a main beam is placed on the track, a first sub-beam and a second sub-beam are placed between the tracks.Type: ApplicationFiled: August 22, 2003Publication date: September 15, 2005Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.Inventors: Shin-ichi Kadowaki, Kousei Sano, Akihiro Arai, Katsuhiko Yasuda, Tomotada Kamei, Hiroaki Yamamoto, Fumitomo Yamasaki