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:
Nov. 21, 2000
Filed:
Jun. 26, 1998
Shinichi Naohara, Kawagoe, JP;
Takashi Suzuki, Kawagoe, JP;
Alex Bradshaw, Kawagoe, JP;
Motoi Kimura, Kawagoe, JP;
Norio Matsuda, Kawagoe, JP;
Kazushige Kawana, Kawagoe, JP;
Kenichi Takahashi, Kawagoe, JP;
Pioneer Electronic Corporation, Tokyo, JP;
Abstract
A focus jump control apparatus of a player for playing a multilayer recording disc surely achieves a focus jump. This apparatus includes: a focusing servo loop for allowing a focal point to trace a recording surface in accordance with a focusing error signal by using a focusing actuator to displace the focal point of read light to a disc in the optical axial direction; and a tracking servo loop for allowing the focal point to trace disc tracks. A loop opening/closing control unit opens/closes focusing/tracking servo loops in response to an instruction and closes the focusing servo loop when the movement of the focal point from one of the recording surfaces to the other. During the movement of the read light focal point, the closing state of the tracking servo loop is maintained. Jump driving means generates a drive signal of the actuator to move the focal point from one of the recording surfaces to the other based on the error signal under the opening/closing control of the focusing/tracking servo loops.