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:
Aug. 05, 2003
Filed:
Apr. 25, 2000
Masayoshi Yoshida, Saitama, JP;
Yoshitaka Shimoda, Saitama, JP;
Pioneer Corporation, Tokyo, JP;
Abstract
A pre-pit detection unit having pre-pit detection circuits ( and ) respectively corresponding to beam intensity in mark and space periods that are provided in parallel on the output side of a push-pull circuit ( ) for generating a pre-data signal. The pre-pit detection unit finally outputs the OR of the outputs of both pre-pit detection circuits as a pre-pit detection signal (l). An AGC circuit ( and ) for making the maximum amplitude of a radial push-pull signal (d) obtainable from said push-pull circuit coincide with a reference value is provided in the preceding stages of pre-pit detecting comparators ( and ) in the respective pre-pit detection circuits.