Ricoh Company, Ltd.

Hiroko Iwasaki

Makoto Harigaya

Katsuyuki Yamada

Yukio Ide

Yoshiyuki Kageyama

Hiroshi Deguchi

Yujiro Kaneko

Kenichi Aihara

Kyohji Hattori

Yuki Nakamura

Eiji Noda

Fumiya Ohmi

Masaetsu Takahashi

Michiaki Shinotsuka

Yoshitaka Hayashi

Michiharu Abe

Yoshihiko Hotta

Tetsuo Watanabe

Akihiko Okamoto

Naoshi Mishima

Osamu Nonoyama

Narihito Kojima

Ippei Ogawa

Michiaki Shinozuka

Yoshiyuki Kageyma

A method and apparatus for initializing optical recording media is provided that detects the intensity of a reflective light off of an optical recording media and analyzes the initializing condition based on the detected intensity during an initializing process. The light is radiated on a rotating phase-change optical recording medium. The light may be moved in a radial direction of the optical recording medium. The detected intensity of the reflected light may be used to identify crystallized portions and amorphous portions of the optical media. The initialization process can be adaptively controlled to ensure proper initialization. If desired, re-initialization can be limited to those areas detected to be outside of the predetermined parameters.

Method and apparatus for initializing optical recording media

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 optical information memory medium, including, in the stated order a substrate, an optical information memory layer which is capable of memorizing information therein, and a reversible display recording layer which is capable of rewritably recording therein, in a visibly recognizable form, at least part of an information corresponding to the information memorized in the optical information memory layer, and a display recording method using the optical information memory medium are disclosed.

Optical information memory medium and display recording method using 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 &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.

A method and apparatus for initializing optical recording media is provided that detects the intensity of a reflective light off of an optical recording media and analyzes the initializing condition based on the detected intensity during an initializing process. The light is radiated on a rotating phase-change optical recording medium. The light maybe moved in a radial direction of the optical recording medium. The detected intensity of the reflected light may be used to identify crystallized portions and amorphous portions of the optical media. The initialization process can be adaptively controlled to ensure proper initialization. If desired, re-initialization can be limited to those areas detected to be outside of the predetermined parameters.

In a material for a heat-resistant protection layer and constituting one of the components of a phase variation type recording medium , at least one compound having a thermal conductivity of higher than 10 W/m&middot;deg inclusive in a bulk state is contained. This kind of material realizes a phase variation type optical data recording medium having a high erasure ratio and allowing data to be repeatedly recorded and erased a number of times by small power even at the time of high-speed recording and erasure.

Optical data recording medium and material for heat-resistant protection layer for the same

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

Both a low-linear-velocity recording and a high-linear-velocity recording can be effectively performed by an optical recording method for recording information on a phase-change optical recording medium which is recordable at a low linear velocity and a high linear velocity greater than the low linear velocity. A ratio (Pel/Pwl) of an erasing power Pel to a recording power Pwl in the low-linear-velocity recording and a ratio (Peh/Pwh) of an erasing power Peh to a recording power Pwh in the high-linear-velocity recording are determined so that the ratio (Pel/Pwl) and the ratio (Peh/Pwh) satisfy the relationship &lcub;(Pel/Pwl)<(Peh/Pwh)&rcub;.

Optical recording method for a rewritable phase-change optical recording medium

An optical data storage medium includes a substrate, an optical data storage layer overlaid on the substrate and a reversible image recording layer overlaid on the optical data storage layer, in which information is recorded in the reversible image recording layer so as to be visible. The reversible image recording layer, which includes a matrix resin and a low-molecular-weight organic substance dispersed in the matrix resin, may preferably be thermosensitive and change its transparency or color tone in response to heat.

Optical data storage medium capable of reversibly displaying information

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.

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Tokyo, Japan

Hiroko Iwasaki