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:
Jan. 03, 2012
Filed:
May. 15, 2008
Akemi Hirotsune, Saitama, JP;
Junko Ushiyama, Kokubunji, JP;
Hiroyuki Minemura, Kokubunji, JP;
Takahiro Kurokawa, Fujisawa, JP;
Harukazu Miyamoto, Higashimurayama, JP;
Akemi Hirotsune, Saitama, JP;
Junko Ushiyama, Kokubunji, JP;
Hiroyuki Minemura, Kokubunji, JP;
Takahiro Kurokawa, Fujisawa, JP;
Harukazu Miyamoto, Higashimurayama, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
Regarding a signal recorded with a first frequency in a recording area on a specific first recording layer and a signal recorded with a second frequency different from the first frequency in a recording area on a second recording layer which might cause interlayer crosstalk in relation to the first recording layer, a reproducing signal measurement method for a multilayer optical recording medium having at least three recording layers includes reproducing the signal recorded in the recording area on the first recording layer, separating signals recorded respectively with the first and second frequencies, discriminating signal amplitude of the first frequency and a maximum value in signal amplitude of the second frequency, and calculating a signal amplitude ratio between them to measure interlayer crosstalk contained in the signal reproduced from the recording area on the first recording layer. Thus, the interlayer crosstalk quantity caused by unnecessary light can be measured quantitatively.