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.

Date of Patent:
Jul. 11, 2000

Filed:

Jun. 15, 1999
Applicant:
Inventors:

Jin-Yong Kim, Kyungki-Do, KR;

Dae-Young Kim, Seoul, KR;

Man-Hyung Lee, Seoul, KR;

Song-Chan Park, Kyungki-Do, KR;

In-Sang Song, Kyungki-Do, KR;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
369 58 ; 369 54 ;
Abstract

An improved optical pick-up apparatus capable of reading data irrespective of disc type capable of reading various kinds of discs having different thicknesses and writing densities using only one pick-up apparatus, which includes a light source; a beam splitter for passing through or splitting a beam from the light source; an objective lens for condensing the beam onto corresponding disc among discs having different thicknesses and different densities; a numerical aperture control unit for controlling an effective numerical aperture of the objective lens so as to execute a focussing operation with respect to a certain disc; and a photo-detector for receiving the beam reflected by the disc and transmitted from the beam splitter.


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