Patents by Inventor Takashi Shibaguchi
Takashi Shibaguchi 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: 7507523Abstract: An optical information recording medium is provided. This medium at least stores information that indicates a maximum recording linear velocity Vh. The medium comprises a substrate having a concentric circular guide groove. This guide grove has land portions and groves portions. At least a phase change type recording layer is formed on the substrate. The recording layer has such a composition and thickness that a dislocation linear velocity V satisfies the relation V?Vh×0.85.Type: GrantFiled: September 28, 2001Date of Patent: March 24, 2009Assignee: Ricoh Company, LtdInventors: Katsuyuki Yamada, Shinya Narumi, Makoto Harigaya, Katsuhiko Tani, Noriyuki Iwata, Nobuaki Onagi, Kazunori Ito, Takashi Shibaguchi, Eiko Hibino, Hajime Yuzurihara, Hiroko Ohkura, Akira Shimofuku, Yuki Nakamura
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Patent number: 7366075Abstract: An optical recording medium has a phase-change recording layer containing Sb and Te as essential elements therefor, to which is added at least one element selected from the group consisting of Ag, Au, Cu, Zn, B, Al, Ga, In, Si, Ge, Sn, Pb, N, P, Bi, La, Ce, Gd, and Tb, the recording layer being capable of assuming an amorphous phase changed from a crystalline phase by the application of a laser beam thereto, thereby optically recording information. Recording marks are formed in the recording medium by converting a light emission wave of laser beam into a recording pulse train comprising a plurality of on-pulses and off-pulses, with a recording frequency being continuously changed corresponding to the location of each of the recording marks in the radial direction of said recording medium. A recording apparatus has laser beam driving circuit means, signal generation means, and signal transmission means for achieving the above recording method.Type: GrantFiled: July 21, 2006Date of Patent: April 29, 2008Assignee: Ricoh Company, ltd.Inventors: Kazunori Ito, Michiharu Abe, Makoto Harigaya, Takashi Shibaguchi, Eiko Suzuki, Nobuaki Onagi, Hiroko Tashiro, Yoshiyuki Kageyama
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Patent number: 7364781Abstract: An optical recording medium including a recording layer which includes a reversible phase-change recording material, the recording layer being capable of writing information therein, reading written information therefrom, and rewriting written information by utilizing the reversible phase change of the phase-change recording material, wherein when a recording mark formed in the recording layer is repeatedly read 5000 times, using a continuous wave laser beam having such an intensity Pr that satisfies the condition of 1.1?R?2.0, in which R is ?repeat/?1 as defined in the specification, the optical recording medium satisfies a relationship of d1>dow as defined in the specification. The phase-change recording material, a method of producing the optical recording medium, and a method of writing information in the optical recording medium, reading written information therefrom and rewriting written information therein are proposed.Type: GrantFiled: April 24, 2006Date of Patent: April 29, 2008Assignee: Ricoh Company, Ltd.Inventors: Kazunori Ito, Eiko Hibino, Makoto Harigaya, Takashi Shibaguchi, Hajime Yuzurihara, Nobuaki Onagi, Hiroko Ohkura, Katsuhiko Tani, Noriyuki Iwata
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Publication number: 20060256706Abstract: An optical recording medium has a phase-change recording layer containing Sb and Te as essential elements therefor, to which is added at least one element selected from the group consisting of Ag, Au, Cu, Zn, B, Al, Ga, In, Si, Ge, Sn, Pb, N, P, Bi, La, Ce, Gd, and Tb, the recording layer being capable of assuming an amorphous phase changed from a crystalline phase by the application of a laser beam thereto, thereby optically recording information. Recording marks are formed in the recording medium by converting a light emission wave of laser beam into a recording pulse train comprising a plurality of on-pulses and off-pulses, with a recording frequency being continuously changed corresponding to the location of each of the recording marks in the radial direction of said recording medium. A recording apparatus has laser beam driving circuit means, signal generation means, and signal transmission means for achieving the above recording method.Type: ApplicationFiled: July 21, 2006Publication date: November 16, 2006Inventors: Kazunori Ito, Michiharu Abe, Makoto Harigaya, Takashi Shibaguchi, Eiko Suzuki, Nobuaki Onagi, Hiroko Tashiro, Yoshiyuki Kageyama
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Patent number: 7102977Abstract: An optical recording medium has a phase-change recording layer containing Sb and Te as essential elements therefor, to which is added at least one element selected from the group consisting of Ag, Au, Cu, Zn, B, Al, Ga, In, Si, Ge, Sn, Pb, N, P, Bi, La, Ce, Gd, and Tb, the recording layer being capable of assuming an amorphous phase changed from a crystalline phase by the application of a laser beam thereto, thereby optically recording information. Recording marks are formed in the recording medium by converting a light emission wave of laser beam into a recording pulse train comprising a plurality of on-pulses and off-pulses, with a recording frequency being continuously changed corresponding to the location of each of the recording marks in the radial direction of said recording medium. A recording apparatus has laser beam driving circuit means, signal generation means, and signal transmission means for achieving the above recording method.Type: GrantFiled: March 28, 2005Date of Patent: September 5, 2006Assignee: Ricoh Company, Ltd.Inventors: Kazunori Ito, Michiharu Abe, Makoto Harigaya, Takashi Shibaguchi, Eiko Suzuki, Nobuaki Onagi, Hiroko Tashiro, Yoshiyuki Kageyama
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Publication number: 20060188686Abstract: An optical recording medium including a recording layer which includes a reversible phase-change recording material, the recording layer being capable of writing information therein, reading written information therefrom, and rewriting written information by utilizing the reversible phase change of the phase-change recording material, wherein when a recording mark formed in the recording layer is repeatedly read 5000 times, using a continuous wave laser beam having such an intensity Pr that satisfies the condition of 1.1?R?2.0, in which R is ?repeat/?1 as defined in the specification, the optical recording medium satisfies a relationship of d1>dow as defined in the specification. The phase-change recording material, a method of producing the optical recording medium, and a method of writing information in the optical recording medium, reading written information therefrom and rewriting written information therein are proposed.Type: ApplicationFiled: April 24, 2006Publication date: August 24, 2006Inventors: Kazunori Ito, Eiko Hibino, Makoto Harigaya, Takashi Shibaguchi, Hajime Yuzurihara, Nobuaki Onagi, Hiroko Ohkura, Katsuhiko Tani, Noriyuki Iwata
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Publication number: 20050169149Abstract: An optical recording medium has a phase-change recording layer containing Sb and Te as essential elements therefor, to which is added at least one element selected from the group consisting of Ag, Au, Cu, Zn, B, Al, Ga, In, Si, Ge, Sn, Pb, N, P, Bi, La, Ce, Gd, and Tb, the recording layer being capable of assuming an amorphous phase changed from a crystalline phase by the application of a laser beam thereto, thereby optically recording information. Recording marks are formed in the recording medium by converting a light emission wave of laser beam into a recording pulse train comprising a plurality of on-pulses and off-pulses, with a recording frequency being continuously changed corresponding to the location of each of the recording marks in the radial direction of said recording medium. A recording apparatus has laser beam driving circuit means, signal generation means, and signal transmission means for achieving the above recording method.Type: ApplicationFiled: March 28, 2005Publication date: August 4, 2005Inventors: Kazunori Ito, Michiharu Abe, Makoto Harigaya, Takashi Shibaguchi, Eiko Suzuki, Nobuaki Onagi, Hiroko Tashiro, Yoshiyuki Kageyama
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Patent number: 6884487Abstract: An optical recording medium including a recording layer which includes a reversible phase-change recording material, the recording layer being capable of writing information therein, reading written information therefrom, and rewriting written information by utilizing the reversible phase change of the phase-change recording material, wherein when a recording mark formed in the recording layer is repeatedly read 5000 times, using a continuous wave laser beam having such an intensity Pr that satisfies the condition of 1.1?R?2.0, in which R is ?repeat/?1 as defined in the specification, the optical recording medium satisfies a relationship of d1>dow as defined in the specification. The phase-change recording material, a method of producing the optical recording medium, and a method of writing information in the optical recording medium, reading written information therefrom and rewriting written information therein are proposed.Type: GrantFiled: January 31, 2003Date of Patent: April 26, 2005Assignee: Ricoh Company, Ltd.Inventors: Kazunori Ito, Eiko Hibino, Makoto Harigaya, Takashi Shibaguchi, Hajime Yuzurihara, Nobuaki Onagi, Hiroko Ohkura, Katsuhiko Tani, Noriyuki Iwata
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Patent number: 6884488Abstract: An optical recording medium has a phase-change recording layer containing Sb and Te as essential elements therefor, to which is added at least one element selected from the group consisting of Ag, Au, Cu, Zn, B, Al, Ga, In, Si, Ge, Sn, Pb, N, P, Bi, La, Ce, Gd, and Tb, the recording layer being capable of assuming an amorphous phase changed from a crystalline phase by the application of a laser beam thereto, thereby optically recording information. Recording marks are formed in the recording medium by converting a light emission wave of laser beam into a recording pulse train comprising a plurality of on-pulses and off-pulses, with a recording frequency being continuously changed corresponding to the location of each of the recording marks in the radial direction of said recording medium. A recording apparatus has laser beam driving circuit means, signal generation means, and signal transmission means for achieving the above recording method.Type: GrantFiled: May 12, 2004Date of Patent: April 26, 2005Assignee: Ricoh Company, LimitedInventors: Kazunori Ito, Michiharu Abe, Makoto Harigaya, Takashi Shibaguchi, Eiko Suzuki, Nobuaki Onagi, Hiroko Tashiro, Yoshiyuki Kageyama
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Publication number: 20050058055Abstract: An optical recording medium including a recording layer which includes a reversible phase-change recording material, the recording layer being capable of writing information therein, reading written information therefrom, and rewriting written information by utilizing the reversible phase change of the phase-change recording material, wherein when a recording mark formed in the recording layer is repeatedly read 5000 times, using a continuous wave laser beam having such an intensity Pr that satisfies the condition of 1.1?R?2.0, in which R is ?repeat/?1 as defined in the specification, the optical recording medium satisfies a relationship of d1>dow as defined in the specification. The phase-change recording material, a method of producing the optical recording medium, and a method of writing information in the optical recording medium, reading written information therefrom and rewriting written information therein are proposed.Type: ApplicationFiled: October 27, 2004Publication date: March 17, 2005Inventors: Kazunori Ito, Eiko Hibino, Makoto Harigaya, Takashi Shibaguchi, Hajime Yuzurihara, Nobuaki Onagi, Hiroko Ohkura, Katshuiko Tani, Noriyuki Iwata
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Publication number: 20040209036Abstract: An optical recording medium has a phase-change recording layer containing Sb and Te as essential elements therefor, to which is added at least one element selected from the group consisting of Ag, Au, Cu, Zn, B, Al, Ga, In, Si, Ge, Sn, Pb, N, P, Bi, La, Ce, Gd, and Tb, the recording layer being capable of assuming an amorphous phase changed from a crystalline phase by the application of a laser beam thereto, thereby optically recording information. Recording marks are formed in the recording medium by converting a light emission wave of laser beam into a recording pulse train comprising a plurality of on-pulses and off-pulses, with a recording frequency being continuously changed corresponding to the location of each of the recording marks in the radial direction of said recording medium. A recording apparatus has laser beam driving circuit means, signal generation means, and signal transmission means for achieving the above recording method.Type: ApplicationFiled: May 12, 2004Publication date: October 21, 2004Inventors: Kazunori Ito, Michiharu Abe, Makoto Harigaya, Takashi Shibaguchi, Eiko Suzuki, Nobuaki Onagi, Hiroko Tashiro, Yoshiyuki Kageyama
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Patent number: 6777057Abstract: An optical recording medium has a phase-change recording layer containing Sb and Te as essential elements therefor, to which is added at least one element selected from the group consisting of Ag, Au, Cu, Zn, B, Al, Ga, In, Si, Ge, Sn, Pb, N, P, Bi, La, Ce, Gd, and Tb, the recording layer being capable of assuming an amorphous phase changed from a crystalline phase by the application of a laser beam thereto, thereby optically recording information. Recording marks are formed in the recording medium by converting a light emission wave of laser beam into a recording pulse train comprising a plurality of on-pulses and off-pulses, with a recording frequency being continuously changed corresponding to the location of each of the recording marks in the radial direction of said recording medium. A recording apparatus has laser beam driving circuit means, signal generation means, and signal transmission means for achieving the above recording method.Type: GrantFiled: February 7, 2003Date of Patent: August 17, 2004Assignee: Ricoh Company, Ltd.Inventors: Kazunori Ito, Michiharu Abe, Makoto Harigaya, Takashi Shibaguchi, Eiko Suzuki, Nobuaki Onagi, Hiroko Tashiro, Yoshiyuki Kageyama
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Publication number: 20030143365Abstract: An optical recording medium including a recording layer which includes a reversible phase-change recording material, the recording layer being capable of writing information therein, reading written information therefrom, and rewriting written information by utilizing the reversible phase change of the phase-change recording material, wherein when a recording mark formed in the recording layer is repeatedly read 5000 times, using a continuous wave laser beam having such an intensity Pr that satisfies the condition of 1.1≦R≦2.0, in which R is &sgr;repeat/&sgr;1 as defined in the specification, the optical recording medium satisfies a relationship of d1>dow as defined in the specification. The phase-change recording material, a method of producing the optical recording medium, and a method of writing information in the optical recording medium, reading written information therefrom and rewriting written information therein are proposed.Type: ApplicationFiled: January 31, 2003Publication date: July 31, 2003Inventors: Kazunori Ito, Eiko Hibino, Makoto Harigaya, Takashi Shibaguchi, Hajime Yuzurihara, Nobuaki Onagi, Hiroko Ohkura, Katsuhiko Tani, Noriyuki Iwata
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Publication number: 20030124298Abstract: An optical recording medium has a phase-change recording layer containing Sb and Te as essential elements therefor, to which is added at least one element selected from the group consisting of Ag, Au, Cu, Zn, B, Al, Ga, In, Si, Ge, Sn, Pb, N, P, Bi, La, Ce, Gd, and Tb, the recording layer being capable of assuming an amorphous phase changed from a crystalline phase by the application of a laser beam thereto, thereby optically recording information. Recording marks are formed in the recording medium by converting a light emission wave of laser beam into a recording pulse train comprising a plurality of on-pulses and off-pulses, with a recording frequency being continuously changed corresponding to the location of each of the recording marks in the radial direction of said recording medium. A recording apparatus has laser beam driving circuit means, signal generation means, and signal transmission means for achieving the above recording method.Type: ApplicationFiled: February 7, 2003Publication date: July 3, 2003Inventors: Kazunori Ito, Michiharu Abe, Makoto Harigaya, Takashi Shibaguchi, Eiko Suzuki, Nobuaki Onagi, Hiroko Tashiro, Yoshiyuki Kageyama
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Patent number: 6548137Abstract: An optical recording medium has a phase-change recording layer containing Sb and Te as essential elements therefor, to which is added at least one element selected from the group consisting of Ag, Au, Cu, Zn, B, Al, Ga, In, Si, Ge, Sn, Pb, N, P, Bi, La, Ce, Cd, and Tb, the recording layer being capable of assuming an amorphous phase changed from a crystalline phase by the application of a laser beam thereto, thereby optically recording information. Recording marks are formed in the recording medium by converting a light emission wave of laser beam into a recording pulse train comprising a plurality of on-pulses and off-pulses, with a recording frequency being continuously changed corresponding to the location of each of the recording marks in the radial direction of said recording medium. A recording apparatus has laser beam driving circuit means, signal generation means, and signal transmission means for achieving the above recording method.Type: GrantFiled: May 11, 2000Date of Patent: April 15, 2003Assignee: Ricoh Company, Ltd.Inventors: Kazunori Ito, Michiharu Abe, Makoto Harigaya, Takashi Shibaguchi, Eiko Suzuki, Nobuaki Onagi, Hiroko Tashiro, Yoshiyuki Kageyama
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Publication number: 20030031823Abstract: An optical recording medium has a phase-change recording layer containing Sb and Te as essential elements therefor, to which is added at least one element selected from the group consisting of Ag, Au, Cu, Zn, B, Al, Ga, In, Si, Ge, Sn, Pb, N, P, Bi, La, Ce, Gd, and Tb, the recording layer being capable of assuming an amorphous phase changed from a crystalline phase by the application of a laser beam thereto, thereby optically recording information. Recording marks are formed in the recording medium by converting a light emission wave of laser beam into a recording pulse train comprising a plurality of on-pulses and off-pulses, with a recording frequency being continuously changed corresponding to the location of each of the recording marks in the radial direction of said recording medium. A recording apparatus has laser beam driving circuit means, signal generation means, and signal transmission means for achieving the above recording method.Type: ApplicationFiled: May 11, 2000Publication date: February 13, 2003Inventors: Kazunori Ito, Michiharu Abe, Makoto Harigaya, Takashi Shibaguchi, Eiko Suzuki, Nobuaki Onagi, Hiroko Tashiro, Yoshiyuki Kageyama
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Publication number: 20020110063Abstract: An optical information recording medium is provided. This medium at least stores information that indicates a maximum recording linear velocity Vh. The medium comprises a substrate having a concentric circular guide groove. This guide grove has land portions and groves portions. At least a phase change type recording layer is formed on the substrate. The recording layer has such a composition and thickness that a dislocation linear velocity V satisfies the relation V≧Vh×0.85.Type: ApplicationFiled: September 28, 2001Publication date: August 15, 2002Inventors: Katsuyuki Yamada, Shinya Narumi, Makoto Harigaya, Katsuhiko Tani, Noriyuki Iwata, Nobuaki Onagi, Kazunori Ito, Takashi Shibaguchi, Eiko Hibino, Hajime Yuzurihara, Hiroko Okura, Akira Shimofuku, Yuki Nakamura
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Patent number: 6096398Abstract: A phase-change optical recording medium has a substrate, and a lower heat-resistant protective layer, a recording layer capable of recording and erasing information by utilizing changes in the phase of a phase-change recording material in the recording layer, an upper heat-resistant protective layer and a light reflecting and heat dissipating layer, which are successively overlaid on the substrate in this order, the recording material including Ag, In, Sb and Te as the main elements, at least one additional element selected from the group (1) consisting of B, C, N, Al, Si and P, and at least one additional element selected from the group (2) consisting of halogen atoms and alkali metal elements.Type: GrantFiled: November 25, 1998Date of Patent: August 1, 2000Assignee: Ricoh Company, Ltd.Inventors: Hajime Yuzurihara, Hiroshi Deguchi, Michiaki Shinotsuka, Takashi Shibaguchi, Makoto Harigaya, Mikio Kinoshita, Yoshiyuki Kageyama, Michiharu Abe
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Patent number: 5587826Abstract: In an optical beam scanning apparatus having an electrooptic lens, a focal point of a light beam is adjusted to be exactly positioned on a scanning surface by a feedback control at any positions scanned by the light beam during a single scanning period. A deviation of a focal position of the light beam relative to the scanning surface is detected, and a detection signal corresponding to the deviation of the focal position is output. A focusing signal is stored and supplied which corresponds to the detection signal obtained when a focal position of the light beam is exactly positioned on the scanning surface. A differential signal is obtained as a difference between the focusing signal and the detection signal. A level of a driving voltage to be supplied to the electrooptic lens is controlled by a driving voltage controlling signal which is a sum of the differential signal and the focusing signal.Type: GrantFiled: February 27, 1996Date of Patent: December 24, 1996Assignee: Ricoh Company, Ltd.Inventor: Takashi Shibaguchi
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Patent number: 5541761Abstract: In an optical beam scanning apparatus having an electrooptic lens, a focal point of a light beam is adjusted to be exactly positioned on a scanning surface by a feedback control at any positions scanned by the light beam during a single scanning period. A deviation of a focal position of the light beam relative to the scanning surface is detected, and a detection signal corresponding to the deviation of the focal position is output. A focusing signal is stored and supplied which corresponds to the detection signal obtained when a focal position of the light beam is exactly positioned on the scanning surface. A differential signal is obtained as a difference between the focusing signal and the detection signal. A level of a driving voltage to be supplied to the electrooptic lens is controlled by a driving voltage controlling signal which is a sum of the differential signal and the focusing signal.Type: GrantFiled: April 12, 1995Date of Patent: July 30, 1996Assignee: Ricoh Company, Ltd.Inventor: Takashi Shibaguchi