OPTICAL READING DEVICE FOR WRITING/READING ON/FROM MULTI-LAYER OPTICAL DISKS

摘要

An optical information reader for writing/reading of multi-layer optical disks utilizing light beam from the light source directed to optical carder by the lens and receiving reflected or fluorescent light is described. An optical reader includes the device for the reception of reflected of fluorescent light and the detector of the disk writing/reading layer with the aim to determine a required value of compensation or correction of spherical aberration compare to the calculated one. Optical reader includes also a piezo-ceramic optical element (1, 2, 3, 4) resided in a light beam that is directed from light source to the carder. This piezo-element has a phase difference between central (1, 2) and peripheral (3, 4) zones that depend on sign and value of voltage applied to it. A piezo-ceramic device reduces aberrations by using the phase differences change between its central and peripheral zones as result of current change of record layer thickness.