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. 03, 2001
Filed:
Jul. 07, 1998
Norio Matsuda, Kawagoe, JP;
Hiroyuki Abe, Kawagoe, JP;
Shinichi Naohara, Kawagoe, JP;
Hitoshi Yamazaki, Kawagoe, JP;
Takashi Suzuki, Kawagoe, JP;
Yuichi Kimikawa, Kawagoe, JP;
Kenichi Takahashi, Kawagoe, JP;
Pioneer Electronic Corporation, Tokyo, JP;
Abstract
A focusing control apparatus is designed to perform a focus jumping operation successfully. The apparatus has reading device which irradiates read light to a recording medium,having information recording surfaces formed on at least two layers, respectively, receiving return light of the read light from the recording medium, and generating a read signal; and control device which executes a focus jumping process to generate a drive signal of a focusing actuator to move an optimum light converging position of the read light from one of the recording surfaces to the other based on a focusing error signal that is generated based on the return light. The apparatus further has drop-out detecting device which detects a drop-out of the read signal and vibration detecting device which detects a vibration of the recording medium or reading device. The control device executes the focus jumping process only when the drop-out is not detected and a vibration detection level of the vibration detecting means is lower than a predetermined value.