| 摘要 |
<p>An optical pick-up apparatus comprises a light beam generating source (2), an objective lens (5) for causing a light beam from the light beam generating source (2) to impinge upon a record medium (6) and receiving a reflected light beam from the record medium (6), a composite prism (21) constituted by a glass prism element (22), a crystal prism element (23) and a multi-layer (21a) of dielectric material provided between the glass and crystal prism elements (22, 23) which are bonded together, and so disposed that the light beam from the beam generating source (2) and the reflected light beam from the objective lens (5) enter into the glass prism element (22) through respective different optical paths, the light beam from the beam generating source (2) is directed to the objective lens (5) after passing through the glass prism element (22) and at least two light beams obtained based on the reflected light beam from the objective lens (5) emerge from the crystal prism element(23), and a photodetecting unit (26) for detecting separately the light beams emerging from the crystal prism element (23) of the composite prism (21).</p> |
