Disc player apparatus having a disc rotational speed controller

A disc reproduction apparatus comprising:

• a speed control signal production means for receiving a reproduced signal from a disc, detecting a speed error with respect to a target rotational speed of the rotational speed of disc, and outputting a speed control signal in accordance with this speed error;
• an oscillation means whose oscillation output changes in accordance with said speed control signal;
• a speed control means for detecting a phase difference of said oscillation output with respect to a reference clock and controlling the rotational speed of the disc in accordance with that phase difference;
• a selection means for selecting either of said oscillation output and said reference clock in accordance with a changeover control signal and supplying the same as a system clock to said signal processing means;
• an acceleration detection means for receiving said oscillation output and reference clock and detecting a roll acceleration;
• and
• a control means which outputs said changeover control signal in accordance with the result of a comparison between said detected acceleration and a preliminarily set acceleration to said selection means.

A disc reproduction apparatus comprising:

• a speed control signal production means for receiving a reproduced signal from a disc, detecting a speed error of a rotational speed of the disc with respect to a target rotational speed, and outputting a speed control signal in accordance with this speed error;
• a filter means whose cut-off frequency is variable in accordance with a first changeover control signal and which extracts only a predetermined frequency range of said speed control signal by a related cut-off frequency and outputs the same;
• an oscillation means whose oscillation output changes in accordance with the speed control signal output from said filter means;
• a speed control means for detecting a phase difference of said oscillation output with respect to a reference clock and controlling the rotational speed of the disc in accordance with that phase difference;
• a selection means for selecting either of said oscillation output and said reference clock in accordance with a second changeover control signal and supplying the same as a system clock to said signal processing means;
• an acceleration detection means for detecting a roll acceleration by receiving said oscillation output and reference clock;
• and
• a control means for outputting said first changeover control signal in accordance with a result of a comparison between said detected acceleration and a preliminarily set acceleration to said filter means and outputting the second changeover control signal to said selection means.