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:
Feb. 15, 2000
Filed:
Oct. 29, 1998
Akihito Nakayama, Singapore, SG;
Kenji Shintani, Singapore, SG;
Shunsuke Kohama, Chiba, JP;
Yukari Hashimoto, Yokohama, JP;
Sony Precision Engineering Center (Singapore) Pte Ltd., Singapore, SG;
Disk Ware Co., Ltd., Tokyo, JP;
Abstract
A device for measuring characteristic values of an optical pickup and/or an optical disc capable of detecting tracking signals for measuring characteristic values even if optical disc rotation is not subjected to eccentricity. The device for measuring characteristic values of an optical pickup and/or an optical disc 1 samples outputs of photodetectors of an optical pickup 2 as signals A to F directly by a sample-and-hold circuit 8 and an analog-to-digital converter 10 to store the resulting digital data in a second memory 11. An arithmetic-logic unit 12d measures tracking error signals based on the digital data stored in the second memory 11. A signal generating circuit 25 then sends a sine wave signal to a tracking coil 2b for moving the laser light illuminated on the optical disc along the radius of the disc.