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:
Dec. 07, 1993
Filed:
Apr. 08, 1992
Applicant:
Inventor:
Akio Terada, Tokyo, JP;
Assignee:
Sony Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
369 4429 ; 369 4425 ; 369 4435 ; 2502015 ;
Abstract
The present invention is directed to apparatus. Upon actuation, a system controller controls a digital-to-analog converter to derive a pulse-shaped wave sweep signal. This sweep signal is supplied through an adder and a driver to a focusing actuator, and the focusing actuator drives an objective lens of an optical pickup in response to the sweep signal. According to the focusing servo apparatus of the invention, the focusing servo can be locked in smoothly.