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:
Oct. 18, 2005
Filed:
Feb. 21, 2002
Masahiro Kato, Tokorozawa, JP;
Naoharu Yanagawa, Tokorozawa, JP;
Tatsuhiro Yone, Tokorozawa, JP;
Yuko Muramatsu, Tokorozawa, JP;
Shinji Suzuki, Tokorozawa, JP;
Masahiro Kato, Tokorozawa, JP;
Naoharu Yanagawa, Tokorozawa, JP;
Tatsuhiro Yone, Tokorozawa, JP;
Yuko Muramatsu, Tokorozawa, JP;
Shinji Suzuki, Tokorozawa, JP;
Pioneer Corporation, Tokyo, JP;
Abstract
An AR measuring apparatus receives the reflection light of an optical beam irradiated on an optical recording medium having a recording surface on which pre-pits are repeatedly formed between tracks by means of a first light receiving surface and a second light receiving surface, obtains a push-pull signal based on the difference between light receiving signals from the first and second light receiving surfaces, collects sample data by sampling the push-pull signals for a predetermined period of time, repeats the sampling for the predetermined period of time by a plurality of times, determines whether or not each data value corresponding to a pre-pit position of the sample data by the plurality of times is obtained by a predetermined number of times or greater, and when data values obtained by the predetermined number of times or greater are determined, calculates as an aperture ratio, a ratio between the minimum value and the maximum value of values corresponding to a pre-pit component of the data values obtained by the predetermined number of times or greater.