Servo control system for information storage device

A servo control system for an optical information storage device, said servo control system comprising:

• an optical detector for detecting information stored on an information storage media and for detecting a servo error signal, said optical detector providing a sum information signal output and at least one servo error signal output;
• a motor for positioning said optical detector relative to the information storage media;
• an analog to digital converter for receiving said sum information signal output and said servo error signal output to thereby output a digital servo error signal at a predetermined sampling rate, said digital servo error signal being normalized to said sum information signal by said analog to digital converter;
• a digital signal processor for processing said digital servo error signal and outputting a servo control signal, said digital signal processor including a digital servo compensation transfer function for producing said servo control signal, said digital servo compensation transfer function providing a magnitude null with a minimal phase disturbance occurring at a predetermined frequency being approximately one half of said sampling rate;
• and
• a driver receiving said servo control signal to control said motor.

A servo control system for an information storage device, said servo control system comprising:

• detection means for detecting information stored on an information storage media and for detecting a servo error signal, said detection means providing a sum information signal output and at least one servo error signal output;
• positioning means for positioning said detection means relative to the information storage media;
• an analog to digital converter for receiving said sum information signal output and said servo error signal output and for outputting a digital servo error signal at a predetermined sampling rate, said digital servo error signal being normalized to said sum information signal by said analog to digital converter;
• and
• digital signal processor means for processing said digital servo error signal and outputting a servo control signal, said digital signal processor means including a digital servo compensation transfer function for producing said servo control signal, said digital servo compensation transfer function providing a magnitude null with a minimal phase disturbance occurring at a frequency being approximatly one half of said sampling rate.