Ricoh Company, Ltd.

Hiroko Tashiro

Kazunori Ito

Nobuaki Onagi

Hiroshi Deguchi

Makoto Harigaya

Hajime Yuzurihara

Michiharu Abe

Yoshiyuki Kageyama

Takashi Shibaguchi

Eiko Suzuki

Michiaki Shinotsuka

Masaru Shinkai

Hiroshi Miura

Yasutomo Aman

Katsunari Hanaoka

Wataru Ohtani

Kiyoto Shibata

Hiroyuki Iwasa

Miku Mizutani

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.

Phase-change optical recording medium and recording method and apparatus for the same

In an optical disk substrate film-formation apparatus which prepared an optical disk by forming a thin film on a substrate, the optical disk substrate is held by a holder section. A contact support surface is provided to the holder section which closely contacts at least a portion of the surface of the optical disk substrate rear to the surface where the think film is formed.

Optical device substrate film-formation apparatus, optical disk substrate film-formation method, substrate holder manufacture method, substrate holder, optical disk and a phase-change recording type of optical disk

An optical recording medium which comprises a substrate and a recording layer disposed on the substrate, in which the recording layer comprises Ga and Sb, a content of the Sb is 80 atm % to 95 atm % relative to a total content of the Ga and the Sb in the recording layer, and recording and erasing are carried out by a reversible phase change between an amorphous phase and a crystalline phase in the recording layer.

Optical recording medium, process for manufacturing the same, sputtering target for manufacturing the same, and optical recording process using the same

OPTICAL DEVICE SUBSTRATE FILM-FORMATION APPARATUS, OPTICAL DISK SUBSTRATE FILM-FORMATION METHOD, SUBSTRATE HOLDER MANUFACTURE METHOD, SUBSTRATE HOLDER, OPTICAL DISK AND A PHASE-CHANGE RECORDING TYPE OF OPTICAL DISK

A product for recording information by use of laser light includes a recording layer being able to change between an amorphous state and a crystalline state so as to record information, the recording layer having a thickness falling within a first range defined relative to a wavelength of the laser light, a protection layer having a thickness falling within a second range defined relative to the wavelength of the laser light, a heat releasing layer having a thickness falling within a third range defined relative to the wavelength of the laser light, and a transparent substrate supporting the layers. The first, second, and third ranges are selected such that a phase of the laser light reflected by the amorphous state and a phase of the laser light reflected by the crystalline state have a phase difference larger than a predetermined phase amount.

Phase-change medium usable in phase-difference tracking

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.

Optical information recording medium

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Kanagawa, Japan

Hiroko Tashiro