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. 25, 2003
Filed:
Dec. 28, 1999
Riccardo Caponetto, Catania, IT;
Mario Di Guardo, Gravina di Catania, IT;
Matteo Lo Presti, Misterbianco, IT;
Luigi Fortuna, Siracusa, IT;
Giovanni Muscato, Catania, IT;
STMicroelectronics S.r.l., Agrate Brianza, IT;
Abstract
A control device for a focusing system of a compact disk (CD) reader is provided. The control device uses fuzzy logic incorporated to the audio data processing system of the CD reader which is adapted to detect and segregate a light beam reflected by the surface of the compact disk from an incident light beam to the surface. The fuzzy logic control device receives a focus error signal and a derivative of the focus error. It then calculates, using appropriate membership functions, output signals to provide to a focusing servo-system of the CD reader to adjust the distance of the focal plane from the light beam detecting circuitry.