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:
Jan. 27, 2004
Filed:
Dec. 11, 2000
Anthonius L. J. Dekker, Eindhoven, NL;
Antonius H. M. Akkermans, Eindhoven, NL;
Koninklijke Philips Electronics N.V., Eindhoven, NL;
Abstract
A device according to the invention for scanning a rotating information carrier ( ) comprises a transducer ( ) and controller ( ) for controlling a scanning parameter of the transducer ( ), such as the radial position and the setting of a focus. The controller comprise difference signal generator ( ) for generating a difference signal (RE) which is indicative of a difference between a current value and a desired value of the scanning parameter, and correction signal generator ( ) for generating a correction signal (S ) in response to the difference signal. The correction signal generator ( ) comprise a delay loop ( ) having first in first out memory ( ) for generating a delayed signal (S ) and feedback filter ( ) for filtering the delayed signal (S ). The device comprises rotation speed detector ( ) for generating a clock signal (CL) having a frequency which is indicative of the rotation speed of the information carrier ( ), the delay in the memory ( ) being proportional to a period of the clock signal.