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:
Dec. 29, 2009
Filed:
Oct. 18, 2005
Takuya Tsukagoshi, Sagamihara, JP;
Koji Mishima, Chuo-ku, JP;
Daisuke Yoshitoku, Chuo-ku, JP;
TDK Corporation, Tokyo, JP;
Abstract
A multi-layer optical recording medium in which an effect of an interlayer crosstalk can be accurately measured and a method for evaluating a recording system using the same are provided. The multi-layer optical recording medium has a signal intensity measuring region formed in advance such that each recording layer having an identical address is allowed to have a different reflectivity. A signal intensity variation occurring when data recorded on the signal intensity measuring region is reproduced is measured to obtain signal intensity variation information. The method calculates a coherence parameter m describing the coherence of a recording system from the signal intensity variation information and reflectivity information obtained at each of the recording layers without interference from the other recording layers.