DIGITAL CONTROLLER AND DISC DRIVER

摘要

PURPOSE:To suppress eccentric components having frequencies integer times that of motor rotation by varying the idle time corresponding to the variation of period of disturbance. CONSTITUTION:An error signal 8 between an eccentricity detection signal 7 and a control amount signal 12 is subjected to A/D conversion through an A/D converter 1 with a predetermined time interval T1. A sum 11 of digital data 9 subjected to A/D conversion and data 10 outputted from a memory 2 is fed through a phase lead compensator 3 to a tracking actuator 5. The memory 2 brings the memory address (K) to 1 upon reception of a phase signal for every revolution of a motor when an interruption signal is provided with a time interval T2. When no phase signal is received, the memory address (K) is not varied. Thereafter, the digital data 9 are added to the memory data and the added value is stored at the memory address (K), while simultaneously the memory address (K) is brought to (K+1).