Ricoh Company, Ltd.

Yoshiyuki Kageyama

Makoto Harigaya

Yukio Ide

Hiroko Iwasaki

Hiroshi Deguchi

Katsuyuki Yamada

Michiharu Abe

Kazunori Ito

Masaetsu Takahashi

Michiaki Shinotsuka

Nobuaki Onagi

Takashi Shibaguchi

Hajime Yuzurihara

Yoshitaka Hayashi

Hiroko Tashiro

Eiko Suzuki

Hiroshi Miura

Yujiro Kaneko

Kenji Kameyama

Eiko Hibino

Itaru Fujimura

Hiroko Ohkura

Miku Mizutani

Kohichi Ohshima

Mikio Kinoshita

Seiichi Ohseto

Seiichi Oseto

Masako Kunita

Osamu Nonoyama

Noriyuki Iwata

Mikiko Abe

Teruyuki Ohnuma

Katsuhiko Tani

Michiaki Shinozuka

Hiroko Okura

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

A sputtering target contains a target material including as constituent elements Ag, In, Te and Sb with the respective atomic percents (atom. %) of &#x3b1;, &#x3b2;, &#x3b3; and &#x3b4; thereof being in the relationship of 0.5&#x2266;&#x3b1;&#x3c;8, 5&#x2266;&#x3b3;&#x2266;23, 17&#x2266;&#x3b3;&#x2266;38, 32&#x2266;&#x3b4;&#x2266;73, &#x3b1;&#x2266;&#x3b3;, and &#x3b1;+&#x3b2;+&#x3b3;+&#x3b4;=100, and a method of producing the above sputtering target is provided.

Method of producing a sputtering target

An information recording method including irradiating a phase change recording layer of an optical recording medium with either a multi-pulse laser light train having a recording power of Pw or laser light having an erasing power Pe to record a mark having a length nT in the recording layer, wherein n is an integer of from 3 to 14 and T represents a clock cycle, wherein the multi-pulse laser light train has a constitution such that a heating pulse and a cooling pulse are alternated and the number of heating pulses and the number of cooling pulses each increases by 1 when n increases by 2, and wherein when n is from 6 to 14, the last heating pulse and last cooling pulse have a pulse width of from 0.5T to 0.9T and from 0.7T to 1.5T, respectively.

Information recording method and optical recording medium therefor

A phase-change optical information recording medium capable of recording information therein, reproducing recorded information therefrom, rewriting recorded information, and erasing recorded information therefrom, which phase-change optical information recording medium is provided with a recording layer containing therein a phase-change recording material including Ge, Ga, Sb, Te, and one element selected from the group consisting of Mg and Ca, which recording material is capable of performing a reversible phase transition from a noncrystalline phase to a crystalline phase and vice verse with the application of an electromagnetic wave thereto.

Phase-change optical information recording medium

An optical recording medium comprising a recording layer which comprises a phase-change recording material causing a reversible phase change between a crystalline phase and an amorphous phase by irradiation with an electromagnetic wave, wherein the phase-change recording material mainly comprises materials expressed by the composition formula X&agr;Ge&bgr;Mn&ggr;Sb&dgr;Te&egr; with each of the components respectively fulfills 0&lE;&agr;&lE;5, 1&lE;&bgr;&lE;5, 1&lE;&ggr;&lE;10, 65 &lE;&dgr;<80, 15&lE;&egr;&lE;25, and &agr;&lE;&ggr; (where X expresses at least one of Ga and Sn, &agr;, &bgr;, &ggr;, &dgr;, and &egr; expresses atomic percentage, and fulfills &agr;&plus;&bgr;&plus;&ggr;&plus;&dgr;&plus;&egr;&equals;100).

Optical recording medium and recording method

A sputtering target contains a target material including as constituent elements Ag, In, Te and Sb with the respective atomic percents (atom. %) of &agr;, &bgr;, &ggr; and &dgr; thereof being in the relationship of 0.5&lE;&agr;<8, 5&lE;&bgr;&lE;23, 17&lE;&ggr;&lE;38, 32&lE;&dgr;&lE;73, &agr;&lE;&bgr;, and &agr;&plus;&bgr;&plus;&ggr;&plus;&dgr;&equals;100, and a method of producing the above sputtering target is provided. An optical recording medium includes a recording layer containing a phase-change recording material which includes as constituent elements Ag, In, Te and Sb with the respective atomic percents of &agr;, &bgr;, &ggr; and &dgr; thereof being in the relationship of 1&lE;&agr;<6, 7&lE;&bgr;&lE;20, 20&lE;&ggr;&lE;35, 35&lE;&dgr;&lE;70, and &agr;&plus;&bgr;&plus;&ggr;&plus;&dgr;&equals;100, and is capable of recording and erasing information by utilizing the phase change of the recording material in the recording layer. A method of forming the above recording layer for the optical recording medium is also provided. In addition, there is provided an optical recording method using the above-mentioned phase-change optical recording medium.

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.

A sputtering target for fabricating a recording layer of a phase-change type optical recording medium contains a compound or mixture including as constituent. elements Ag, In, Te and Ob with the respective atomic percent (atom. %) of &agr;, &bgr;, &ggr; and &dgr; thereof being in the relationship of 2&lE;&agr;&lE;30, 3&lE;&bgr;&lE;30, 10&lE;&ggr;&lE;50, 15&lE;&dgr;&lE;83 and &agr;&plus;&bgr;&plus;&ggr;&plus;&dgr;&equals;100, and a method of producing the above sputtering target is provided. A phase-change type optical recording medium includes a recording layer containing as constituent elements Ag, In, To and Sb with the respective atomic percent of &agr;, &bgr;, &ggr; and &dgr; thereof being in the relationship of 0<&agr;&lE;30, 0<&bgr;&lE;30, 10&lE;&ggr;&lE;50, 10&lE;&dgr;&lE;80, and &agr;&plus;&bgr;&plus;&ggr;&plus;&dgr;&equals;100, and is capable of recording and erasing information by utilizing the phase changes of a recording material in the recording layer. A method of fabricating the above phase-change type optical recording medium is also provided.

Sputtering target, method of producing the target, optical recording medium fabricated by using the sputtering target, and method of fabricating the optical recording medium

Sputtering target, method of producing the target, optical recording medium fabricated by using the sputtering target, and method of forming recording layer for the optical recording medium

A sputtering target for fabricating a recording layer of a phase-change type optical recording medium contains a compound or mixture including as constituent elements Ag, In, Te and Sb with the respective atomic percent (atom. %) of &agr;, &bgr;, &ggr; and &dgr; thereof being in the relationship of 2&lE;&agr;&lE;30, 3&lE;&bgr;&lE;30, 10&lE;&ggr;&lE;50, 15&lE;&dgr;&lE;83 and &agr;&plus;&bgr;&plus;&ggr;&plus;&dgr;&equals;100, and a method of producing the above sputtering target is provided. A phase-change type optical recording medium includes a recording layer containing as constituent elements Ag, In, Te and Sb with the respective atomic percent of &agr;, &bgr;, &ggr; and &dgr; thereof being in the relationship of 0<&agr;&lE;30, 0<&bgr;&lE;30, 10&lE;&ggr;&lE;50, 10&lE;&dgr;&lE;80, and &agr;&plus;&bgr;&plus;&ggr;&plus;&dgr;&equals;100, and is capable of recording and erasing information by utilizing the phase changes of a recording material in the recording layer. A method of fabricating the above phase-change type optical recording medium is also provided.

An optical information recording medium includes a substrate with guide grooves thereon, a recording layer provided on the substrate, including a recording material of which phase is reversibly changeable from a stable state to a semistable state and vice versa, a heat-resistant dielectric protective layer provided on the recording layer, including a protective material which includes Zn, Si, S and O, and a light reflection and heat dissipation layer provided on the heat-resistant dielectric protective layer.

Optical information recording medium

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Kanagawa, Japan

Yoshiyuki Kageyama