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:
Apr. 15, 2003
Filed:
Feb. 27, 2002
Chin-Sung Liu, Maio-Li, TW;
Shin-Ter Tsai, Taipei, TW;
Industrial Technology Research Institute, Hsin-Chu, TW;
Abstract
A dual optical pick-up head for accessing CD, CD-R and DVD discs is provided. The provided dual optical pick-up head uses an objective lens and a laser source for DVD discs, and uses another objective lens and another laser source for CD and CD-R discs. Spirit of the invention is that both objective lenses are located in the same lenses holder which connect to a guide rod, and the lenses hold moves only along a radius of the corresponding disc. Moreover, the laser beam produced by any laser source is transmitted through corresponding objective lens to a disc, and the reflected laser beam is transmitted through corresponding objective lens to a PDIC and then a spot is formed and detected. Hence, the location of each objective lens must satiate the requirement that any spot that corresponds to a specific track of disc does not mix with other spots that correspond to other track of disc.