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:
Jul. 31, 2012
Filed:
May. 15, 2008
Yoshinori Ishikawa, Yokohama, JP;
Koji Mishima, Tokyo, JP;
Tsutomu Aoyama, Tokyo, JP;
Takashi Kikukawa, Tokyo, JP;
Yoshinori Ishikawa, Yokohama, JP;
Koji Mishima, Tokyo, JP;
Tsutomu Aoyama, Tokyo, JP;
Takashi Kikukawa, Tokyo, JP;
Hitachi Consumer Electronics Co., Ltd., Tokyo, JP;
TDK Corporation, Tokyo, JP;
Abstract
In a multi-layer optical disc, having three () or more recording layers thereof, for enabling an easy focus lead-in operation onto a desired recording layer, reflectivity of respective recording layers are so determined that a ratio between the reflectivity of the desired recording layer and the reflectivity of other recording layers is equal or greater than a predetermined value, upon basis of the reflectivity of the other recording layers.