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:
Sep. 01, 1998

Filed:

Sep. 06, 1996
Applicant:
Inventors:

Chul-woo Lee, Seoul, KR;

Kyung-hwa Rim, Suwon, KR;

Chong-sam Chung, Sungnam, KR;

Kun-ho Cho, Suwon, KR;

Jang-hoon Yoo, Seoul, KR;

Soo-yeul Jung, Kunpo, KR;

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
369120 ; 369 4423 ; 369 4442 ; 369 94 ;
Abstract

An optical pickup device which is capable of reproducing and recording information from/onto at least two kinds of discs having different thicknesses includes a light source, an objective lens provided along the light path from the light source facing the plane of a disc and having a predetermined effective diameter, a beam splitter provided between the objective lens and the light source, and a photodetector for detecting the beam split from the light splitter and reflected from the disc, wherein the photodetector has a first detection region and a second detection region provided in the peripheral portion of the first detection region. The optical pickup device is simplified and the manufacturing cost therefor is low. Also, by reducing the spherical aberration effect for the light, discs having different thicknesses can be used for a single disc drive.


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