Optical disc apparatus with selectively shiftable seek operation capture range

An optical disc apparatus for reproducing an information data recorded on an optical disc which is rotationally driven with a constant linear velocity, comprising:

• optical pick-up means for reproducing said information data from said optical disc;
• signal detecting means for amplifying and also binarizing output signals from the optical pick-up means, and for outputting a resulted signal as a reproduction signal;
• linear velocity detecting means for detecting the linear velocity of said optical disc from said reproduction signal, and for outputting a linear velocity detection signal corresponding to an error against a predetermined linear velocity;
• and
• clock generating means for generating a clock signal that is synchronous with said reproduction signal, the clock generating means having a phase locked loop configuration including a phase comparator that compares a phase of the clock signal generated by the clock generating means with a phase of said reproduction signal to generate a phase difference signal, a loop filter that filters said phase difference signal to generate a filtered phase difference signal, and a voltage controlled oscillator that generates the clock signal in response to the filtered phase difference signal, the clock generating means further including linear velocity detecting means which selectively generates a linear velocity detection signal, wherein the linear velocity detection signal, when selected to be generated, is combined with the filtered phase difference signal provided to control said voltage controlled oscillator, so that the clock signal which is synchronized with said reproduction signal is generated.