The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 28, 2012
Filed:
Sep. 07, 2005
Hiroyoshi Sekiguchi, Yokohama, JP;
Kazunori Ito, Yokohama, JP;
Hiroshi Deguchi, Yokohama, JP;
Hiroko Ohkura, Yokohama, JP;
Masaki Kato, Sagamihara, JP;
Mikiko Takada, Yokohama, JP;
Hiroyoshi Sekiguchi, Yokohama, JP;
Kazunori Ito, Yokohama, JP;
Hiroshi Deguchi, Yokohama, JP;
Hiroko Ohkura, Yokohama, JP;
Masaki Kato, Sagamihara, JP;
Mikiko Takada, Yokohama, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
An optical recording medium contains a recording layer being composed of a phase-change recording material where at least four elements, Ga, Sb, Sn and Ge are contained and the transfer linear velocity is 20 m/s to 30 m/s, and when the wavelength of a recording/reproducing light is within the range of 650 nm to 665 nm and the recording linear velocity is 20 m/s to 28 m/s, the refractive index Nc and the extinction coefficient Kc in a crystalline state and the refractive index Na and the extinction coefficient Ka in an amorphous state in the recording layer respectively satisfy the following numerical expressions: 2.0≦Nc≦3.0, 4.0≦Kc≦5.0, 4.0≦Na≦5.0, and 2.5≦Ka≦3.1, and information is recordable at the range of 20 m/s to 28 m/s of recording linear velocity.