| 摘要 |
<p>The optical pick-up for optical or magneto-optical disc drive apparatus, has hologram lens element formed of pattern diffracting spherical wave and focusing reflected light onto the detected offset from source. The pick-up includes an aspherical single lens as a light focusing medium formed with a hologram reflective surface disposed on a centre of a medium surface and having a predetermined hologram pattern for reflecting an incident light toward an opposite medium surface and, at the same time, focussing onto points beside the source focal point, a diffracted spherical wave from the reflected light reflected in an optical information medium. A reflective mirror partially scans a light reflected from the hologram reflective surface of the aspherical single lens; and photodetector detects a light bounced off the hologram reflective surface of the aspherical single lens, thereby performing a reproducing/recording operation of optical information.</p> |
