U.S. Philips Corporation

Pieter G Van Leeuwen

Albert M Rijckaert

Franciscus A Kneepkens

Johannes P Inghels

Eduard Van Loo

Christian H Baeten

In a transmission system a sequence of digital symbols including concatenated words, is transmitted by a transmitter (2) via a transmission medium (14) to a receiver (16). In order to reduce the transmission capacity no word synchronizing symbols are introduced in the sequence of digital symbols. In order to achieve word synchronization, a synchronization processor estimates the probability function of one single predetermined string as function of the position of the string in the sequence. The correct position of the words is derived from this probability function.

Transmission system having receiver for recovering words from sequence

A circuit for detecting pulses in an electric input signal, which pulses are superposed on a specific reference level (U.sub.ref), has an input terminal for receiving the electric input signal, at least a first and a second comparator device, switching means (S.sub.1), an output terminal and control signal generator means. The control signal generator means supply a control signal to the switching means (S1) to control the position of the switching means. The input terminal (1) is coupled to a first input of the comparator devices, whose outputs are coupled to a terminal (c and a respectively) of the switching means (S.sub.1). The output terminal (b) of the switching means is coupled to the output terminal. The first comparator device transfers only pulses whose relative amplitude in relation to the reference level exceeds a first value (U.sub.D1). The second comparator device transfers only pulses whose relative amplitude in relation to the reference level exceeds a second value (U.sub.D2). When input terminal receives N1 consecutive pulses whose amplitude relative to the reference level exceeds a specific (third) value (U.sub.D3) the switching means (S.sub.1) have been/are set to position c-b in such a manner that the first comparator is coupled to the output terminal. When subsequently N2 consecutive pulses are counted whose relative amplitude lies between a fourth and a fifth value (U.sub.D4 and U.sub.D5 respectively), such that U.sup.D5 &lt;U.sub.D4 &lt;U.sub.D3, the switching means (S.sub.1) have been/are set to position a-b in such a manner that the second comparator device is coupled to the output terminal. N1 and N2 are integers larger than or equal to 1.

Circuit for detecting pulses, and video recorder comprising the circuit

An arrangement for recording an information signal in a track (T.sub.0, T.sub.1, . . . ) on a record carrier (1), includes an input (20) for receiving the information signal, signal processing circuitry (21) for processing the information signal such that it can be recorded in the track, counting device (23) for counting and for generating an array of subsequent different count signals and for supplying the count signals to an output (24), recording apparatus (25, 26, 27) having at least one recording head (26) for recording the processed information signal in a track on the record carrier, and for recording the count signals in a track on the record carrier and a transport apparatus (34,35) for transporting the record carrier with a certain transport velocity (v.sub.t) in a longitudinal direction of the record carrier. The counting device (23) is adapted to supply count signals such that, independent of the value of the transport velocity during recording, a count signal is recorded in a substantially fixed location, viewed in the longitudinal direction of the record carrier, on said record carrier. Further, in the case that the arrangement is capable of recording a first video signal which is based on 25 pictures per second and of recording a second video signal which is based on 30 pictures per second, the following relation exists between the supply rate F.sub.s of the subsequent different count signals by the count signal generator (23), and D, being the difference between subsequent different count signals generated:

Growing community of inventors

Eindhoven, Netherlands

Pieter G Van Leeuwen