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. 12, 1999
Filed:
Jul. 29, 1997
Hideyo Kamiyama, Tokorozawa, JP;
Pioneer Electronic Corporation, Tokyo, JP;
Abstract
A focus servo pull-in apparatus which discriminates the type of an optical disk and executes focus servo from the optimal position according to the disk type. This focus servo pull-in apparatus performs a focus servo pull-in control operation at the time of reproducing information from one of at least two types of recording media with different distances from surfaces of the recording media to information recording planes where information is recorded. The apparatus comprises a light-emitting unit for irradiating a light beam on an information recording surface of a recording medium in use, a light-receiving unit for receiving reflected light of the light beam from the information recording surface, a moving unit for moving an objective lens for directing the light beam to a focus, in a direction parallel to an optical axis of the light beam, a discrimination unit for discriminating a type of the recording medium in use and outputting a discrimination signal, and a control unit for performing different pull-in controls in accordance with the discrimination signal.