Abstract: An optical recording medium having a number of adjacent tracks for storing digital optical information extending in a first direction. The tracks are separated by a pitch amount in a second direction and each track has a servo field comprising at least one synchronization mark and at least one tracking mark in one of at least three positions on the track. The tracking marks of tracks adjacent in the second direction to a first track are in different positions from each other and from the position of the tracking mark on the first track. The track marks extend in the second direction to give rise to cross-talk from the tracking marks of adjacent tracks when the first track is being read.

Abstract: A method, circuit and system for selectively and adaptively effecting level conditioning of selected samples of a read signal in storage technologies. A circuit embodying the present invention includes sample logic, arithmetic logic and conditioning logic. The sample logic receives samples and provides a main sample and one or more selected neighbor samples. The arithmetic logic compares the main sample to the neighbor samples toward determining satisfaction of selected conditioning criteria. If the selected conditioning criteria are satisfied, the conditioning logic selectively and adaptively effects level conditioning as to the main sample.

Abstract: A method, circuit and system for canceling inter-symbol interference from samples of a read signal in storage technologies. A circuit embodying the present invention includes sample logic, arithmetic logic and cancellation logic. The sample logic receives samples and provides a main sample and one or more selected neighbor samples. The arithmetic logic compares the main sample to the neighbor samples toward determining satisfaction of selected cancellation criteria. If the selected cancellation criteria are satisfied, the cancellation logic selectively and adaptively effects ISI cancellation as to the main sample.

Abstract: Disclosed is a record carrier for optically detectable data storage, apparatus for manufacturing such a record carrier and apparatus for recording and/or reproducing information on such a record carrier. The record carrier is provided with periodic track variations whose period corresponds to a frequency for which the power spectrum of the digitally coded information substantially exhibits a zero point. When scanned by a beam of radiation, the periodic track variations produce periodic modulation in the beam of a frequency corresponding to the period of the track variations in order to generate a clock signal of a frequency equal to the bit frequency during recording or reproduction.