BASE OPTICAL SYSTEM OF AN OPTICAL DISK REPRODUCTION DEVICE, SPECIALLY IN CONNECTION WITH SIMPLIFYING THE STRUCTURE OF A DUAL OPTICAL PICKUP

摘要

PURPOSE: A base optical system of an optical disk reproduction device is provided to comprise an optical path compensation plate for according beams emitted from two laser diodes at one light guide shaft, thereby being useful for a small-sized thin optical disk reproduction device while playing more than two kinds of media in one optical disk reproduction device. CONSTITUTION: The first laser diode(171) emits a beam toward a light guide shaft(101). The second laser diode(172) emits a beam having a wavelength different from the beam of the first laser diode(171), and emits the beam in a direction different from the light guide shaft(101). An optical path compensation plate(160) is formed with gratings, and accords the beam emitted from the second laser diode at the light guide shaft(101). The first and second laser diodes(171,172) are installed to radiate the beams in parallel. The optical path compensation plate(160) is formed with the two-layered gratings.