HOLOGRAPHIC ROM DISC AND HOLOGRAPHIC ROM/DIGITAL DATA DISC COMBO PICK-UP SYSTEM

摘要

The invention alone holographic disc that can be played graphical Rom Rom / digital combo pick-up device and data discs relates to a holographic ROM disk reproducing method for a recording layer, the holographic ROM disk and the reproduction light source for the reference light for firing, and the reference light from the light source was incident on the disk surface at a predetermined angle, each of the diffracted by the incident reference beam and the first optical path for detecting the reproduction light from the hologram recording multiple data layer, the reference beam is diffracted by the reference light by moving the second optical path, the light source for detecting a hologram reproducing light focusing error outputted from the disc surface in a vertical sikimyeo change the angle, the first and the second servo control unit for using an optical detection value detected by the tracking and focusing control of the optical path hole in the graphic ROM disk, the holes located in the graphic ROM disk opposite side focusing holographic ROM disk and it performs servo control by applying the detected focusing error signal to the servo control unit includes a digital data disc pickup for controlling the graphics ROM alone after the initial focusing such focusing operation is interlocked.