| US 7,485,357 B2 | ||
| Optical recording medium | ||
| Mikiko Takada, Yokohama (Japan); Kazunori Ito, Yokohama (Japan); Hiroshi Deguchi, Yokohama (Japan); Masaki Kato, Sagamihara (Japan); Hiroko Ohkura, Yokohama (Japan); and Hiroyoshi Sekiguchi, Yokohama (Japan) | ||
| Assigned to Ricoh Company, Ltd., Tokyo (Japan) | ||
| Filed on May 25, 2006, as Appl. No. 11/441,284. | ||
| Application 11/441284 is a continuation of application No. PCT/JP2004/017429, filed on Nov. 24, 2004. | ||
| Claims priority of application No. 2003-395680 (JP), filed on Nov. 26, 2003. | ||
| Prior Publication US 2006/0246270 A1, Nov. 02, 2006 | ||
| Int. Cl. B32B 3/02 (2006.01) | ||
| U.S. Cl. 428—64.4 [428/64.5; 430/270.13] | 16 Claims |
| 1. An optical recording medium comprising:
a substrate having translucency;
a first protective layer thereon;
a recording layer composed of a phase-change material;
a second protective layer;
a third protective layer; and
a reflective layer,
wherein laser beam irradiation causes phase-change of the recording layer between a crystalline phase and an amorphous phase
thereby at least one of to rewrite and to record information,
wherein the phase-change material comprises Ga, Sb and Sn, Ga content, Sb content, and Sn content satisfy the following formula,
and the total content of Ga, Sb and Sn is at least 92 atomic % of the entire phase-change material:
GaαSbβSnγ (where, α+β+γ=100 atomic %),
where 20≤−2.75α+0.708β+1.18γ−7.56≤43,
and α/(α+β)≤0.12, and
wherein the first protective layer has a film thickness of 40 nm to 200 nm, the recording layer has a film thickness of 6
nm to 20 nm, the second protective layer has a film thickness of 4 nm to 20 nm, the third protective layer has a film thickness
of 2 nm to 10 nm, and the reflective layer has a film thickness of 100 nm to 300 nm.
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