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:
Dec. 28, 2004
Filed:
Jun. 12, 2000
Infineon Technologies, AG, Munich, DE;
Abstract
A lensless optical servo system has an unfocused light source and patterned photodetectors. The unfocused light is reflected by markings on a rotating disk and the reflected light carriers the pattern of the markings to the photodetectors. The convolution of this light pattern and a mating geometric pattern on the photodetectors causes the photodetectors to generate signals representing the position of the track on the disk. In one embodiment, a laser diode and three detectors are formed on the same silicon substrate. Sinusoidal metalization is applied to the detectors in the radial direction. The period of the sinusoidal metalization is two times the tracking pitch of the disk. The metalization on the first detector is approximately ninety degrees behind the metalization on the second detector and the metalization on the third detector is approximately ninety degrees ahead of the metalization on the second detector.