Appliance for recording or playing back information having means for signal generation from a wobble signal

Abstract

The invention proposes an appliance for recording or playing back information having means for signal generation from a wobble signal which is scanned from the undulating track on a recording medium, such as a DVD+RW. According to the invention, a signal scanned from the undulating recording track on the recording medium is supplied to a circuit arrangement for generating a clock signal which is both a square-wave voltage whose phase is synchronous with that of the signal and a signal with an even-numbered multiple of the frequency of the wobble signal contained in the signal. In this regard, the invention provides a phase locked loop which is synchronized with the signal and contains a frequency divider for actuating a digital phase shifter and for providing a clock signal which is a phase-synchronous square-wave voltage having the frequency of the wobble signal. The phase comparator provided is a multiplier which is formed using a changeover switch to which the signal and the inverted signal are applied. For decoding information contained in the waveform of the recording track on the recording medium, a circuit arrangement similar to the aforementioned multiplier is used whose changeover switch is actuated with the clock signal and to which a low-pass filter is connected. The signals generated using the means for signal generation are then made available to further functional units in the appliance for recording or playing back information for recording media with a wobble track.