Abstract: Strategy and methodology by which the various error sources are taken into account and methods applied to compensate substantially entirely for such errors and/or diminish the effect of such errors.

Abstract: A method and system for formatting of recording media.

Abstract: Disclosed is a record carrier for storage of digital data which is provided with a first periodic track variation having a period corresponding to a frequency at which the power spectrum of the digital signals is at a zero level. The first track variation produces a corresponding modulation of the radiation when scanned by a beam so that a clock signal can be derived from the detected radiation for synchronizing readout or recording of the data. The record carrier is further provided with a second periodic track variation in a direction transverse to the track direction having a period of the same order of magnitude, and preferably equal to the period of the first periodic track modulation. The second track variation produces a corresponding modulation of the beam which is detected and is used to generate to a tracking signal, the clock signal being used as phase reference signal for demodulation of the tracking signal.

Abstract: An apparatus for recording optically detectable information in a record carrier provided with information areas arranged in accordance with a spiral or concentric track pattern, which areas alternate with synchronization areas each containing the address of the associated information area. Recording is effected with a first modulated laser beam, while a second beam is projected after the first beam for reading the recorded information. The track pattern has previously been provided with a periodic track modulation of a frequency at which the power spectrum of the information to be recorded has a substantially zero value. The apparatus comprises a first and a second filter for filtering a signal corresponding to the track modulation out of the signal derived by detecting the first or second laser beam reflected or transmitted by the record carrier. In series with the second filter there is included a delay network from which a synchronization signal is available.

Abstract: A disc-shaped record carrier having an information track which is divided into a plurality of sectors per track circumference. Each sector is divided into a data section, in which the data can be recorded, and a synchronizing section. This synchronizing section consists of an optically detectable relief structure and comprises an indicator portion and an address portion. The address portion contains the information about the track number and the sector number. The indicator portion serves to define the beginning of the address portion unambiguously and for this purpose has such a relief structure that the indicator signal produced after cooperation with the radiation beam has a frequency which is clearly distinguishable from signal components resulting from the address portion.

Abstract: A transmission system for a color television signal, in particular a system for recording on and reproducing from a record carrier. The chrominance signal is divided into two separate color signals, which in a line-sequentially alternating fashion are modulated on two separate color carrier waves. The transmitted or recorded color television signal can simply be transformed into both a standard PAL and a standard SECAM signal. Owing to the line sequential alternation of the color signal, color errors which may arise owing to a mutual difference of the transfer characteristics for the two color signals are automatically compensated for in the case of reproduction via a PAL receiver.