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:
Sep. 17, 2013
Filed:
Dec. 20, 2011
Takashi Ohno, Tokyo, JP;
Yoshihiro Noda, Tokyo, JP;
Takashi Ohno, Tokyo, JP;
Yoshihiro Noda, Tokyo, JP;
Mitsubishi Kagaku Media Co., Ltd., Tokyo, JP;
Abstract
A multilayer-type optical recording medium having a translucent recording/reproducing functional layer containing a first protective layer, a second protective layer, a recording layer, a third protective layer, a reflective layer and a fourth protective layer in this order relative to incident laser light. The second protective layer and the fourth protective layer are made of the same kind of material. The refractive index of the second protective layer is higher by at least 0.3 than the refractive index of the first protective layer. When the film thickness of the second protective layer is set as D2, the film thickness of the fourth protective layer is set as D4, and the reflectivity before recording when the laser light is focused on the recording layer is set as R, the derivatives d(R)/d(D2) and d(R)/d(D4) have opposite signs from each other.