Abstract: A disc playback apparatus for reproducing data from a disc having digital data including at least image data or computer data recorded sequentially thereon includes: a spindle motor for rotating the disc; a pick-up assembly for reading and outputting data from the disc, as an electrical signal; waveshaping circuit for shaping the electrical signal into a pulse signal; a clock extracting circuit for extracting a playback clock signal from the pulse signal; a reference clock generating circuit controlled by a reference clock control circuit, for continuously varying and outputting a frequency of the reference clock signal; and a switching circuit which is switched on and off, the reference clock control circuit increasing the frequency of the reference clock signal when the switching circuit is switched on, and decreasing it when the switching circuit is switched off; a rotation servo circuit for controlling the spindle motor so that the frequency of the playback clock signal is consistent with the frequency of