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:
May. 05, 1998
Filed:
Dec. 30, 1996
Applicant:
Inventors:
Jin Yong Kim, Kyungki-Do, KR;
Seong Yun Jeong, Seoul, KR;
Assignee:
LG Electronics, Inc., Seoul, KR;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
369112 ; 369110 ;
Abstract
An improved optical pickup apparatus for different discs which is capable of writing and reading a data onto discs having different writing densities and thicknesses by using one optical pickup apparatus and a liquid crystal deflector (LCD) or a Grating Polarizing Beam Splitter (GPBS). The apparatus includes an objective lens for focusing a beam onto optical discs each having different thicknesses, and a numerical aperture control means for selectively passing through a beam in accordance with the thickness of the optical discs, diffracting a portion of the beam, and controlling the numerical aperture of the objective lens.