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:
Nov. 25, 1980
Filed:
Jun. 30, 1978
John S Winslow, Altadena, CA (US);
Wayne R Dakin, Redondo Beach, CA (US);
MCA Discovision, Inc., Universal City, CA (US);
Abstract
Method and apparatus for controlling the speed of an information storage medium, such as a disc-shaped record carrier, relative to a device for recovering information recorded thereon. The disc includes a plurality of substantially parallel information tracks arranged in a spiral or in concentric circles, and information recorded thereon includes a pilot signal having a predetermined frequency. The apparatus includes means for comparing the phase angle of the recovered pilot signal with the phase angle of a locally generated reference signal, to produce an error signal for controlling the angular velocity of a spindle motor that rotates the disc. The pilot signal includes an equal integral number of cycles on each information track, so its phase angle is aligned on adjacent tracks and the apparatus can continue to operate even when the information recovering device is traversing the disc from one track to another or is not critically positioned with respect to an individual information track.