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:
Sep. 20, 2005
Filed:
Feb. 26, 2002
Seong Yun Jeong, Kyeonggi-do, KR;
Seong Yun Jeong, Kyeonggi-do, KR;
LG Electronics Inc., Seoul, KR;
Abstract
A tilt detecting apparatus of an information-recording medium having a photo diode for detecting a light reflected from an information-recording medium and outputting a light amount signal according to the detected light amount; and a calculating unit for calculating a radial tilt amount by using the light amount signal, wherein the photodiode is divided into a plurality of cells which are identified as regions according to a light amount of the reflected light, based on which a tilt signal is detected. A portion of the reflected light diffracted at the information-recording medium is detected by using the 8-divided photo diode, the region having a large difference in a light amount by the tilt and the region having a small difference in a light amount by the tilt in view of the characteristic of the reflected light are detected. And then, after push-pull values of each region are computed to remove an influence of the radial shift by using the two push-pull values, a corresponding difference between the tilt amounts, thereby obtaining an accurate tilt direction and degree of the information-recording medium.