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. 14, 1993
Filed:
Jun. 29, 1990
Johannes J Verboom, Black Forest, CO (US);
North American Philips Corporation, New York, NY (US);
Abstract
The present invention provides a track format for an optical record carrier that is useful in producing a tracking signal with a substantially constant slope at its zero-crossing point for a range of track pitches. The preferred embodiment of track format is also useful in producing a tracking signal that has a substantially constant amplitude over a range of track pitches. The track format, in the preferred embodiment, employs wobbled pits. The sequence in which the wobbled pits occur alternates between adjacent tracks and the offset of the wobbled pits with respect to the center line of a track remain constant regardless of the track pitch. The preferred embodiment of the track format also includes a reference pit that is used to establish the threshold detection level for the read electronics. The location of the reference alternates between tracks to reduce the effect of radial interference on the signal produced using the reference pit and thereby allow an optimal threshold level to be established.