Abstract: In an information signal recording and reproducing apparatus, reproduced data is equalized by an equalizer and a clock signal synchronized in phase with the reproduced data is generated. An equalizing characteristic of the equalizer is controlled according to a difference in frequency between the clock signal and the reproduced data, and a generating operation for the clock signal is controlled according to a phase difference between the clock signal and the reproduced data. The clock signal thus can be stably generated without being affected by variations of temperature and variations due to aging. The equalizer thus has an adequate equalizing characteristic. The apparatus includes a recording mode and a reproduction mode. In the recording mode, a recording clock signal is generated by a clock signal generating circuit and a digital signal is recorded by using the recording clock signal.

Abstract: A reproducing apparatus includes an equalizer for equalizing reproduced data, a clock generating circuit for generating a clock synchronized with the reproduced data, and a phase difference detector for detecting a phase difference between the reproduced data equalized by the equalizer and the clock. The clock generating circuit receives an output from the phase difference detector as a control signal, and generates a clock of frequency according to the output from the phase difference detector. The equalization characteristic of the equalizer is controlled by the control signal of the clock generating circuit. With this arrangement, it is possible to generate a clock which follows a variation in the frequency of the reproduced data, and it is also possible to realize an optimum equalization characteristic according to the variation in the frequency of the reproduced data.