Patent ID: 6940792

Claim:
An optical disc master board exposing apparatus comprising: a laser light source configured to emit laser light for exposing the optical disc master board painted with a photoresist; an exposure signal generating unit configured to generate an exposure signal in synchronism with a fundamental clock; a light modulator configured to receive and on and off modulate said emitted laser light on the basis of said exposure signal; an optical pickup including a focusing optical system configured to receive said on and off modulated laser light from said light modulator and to then focus said received laser light on to said optical disc master board as an exposure spot; a spindle motor configured to rotate said optical disc master board; a slider configured to move said optical pickup in a radius direction of said optical disc master board; a spindle encoder configured to output a pulse train corresponding to the rotation of said spindle motor; a linear encoder configured to output another pulse train corresponding to the position of said exposure spot on said optical disc master board; and a movement control loop configured to control the rotation of said spindle motor based on rotation and the pulse train output of said spindle encoder, wherein said spindle motor and said slider are further configured to be CLV-driven; and wherein the fundamental clock is configured to provide a pulse train divided to have a frequency proportional to an ideal railroad track length and a spindle rotation ordering pulse train and a slider movement ordering pulse train are generated per one revolution of said spindle motor to thereby generate a CLV drive ordering pulse.