| 摘要 |
<p>Apparatus and method for reading optical discs containing information in the form of tracks of high-spacial-frequency, phase-modulating marks (e.g., depressions or pits) includes means for directing the zero and one first diffraction order of read light returned from the scanned track into superimposed relation on a photodetector and means for predeterminedly masking a portion of the zero diffraction order light so that its magnitude is more equal to that of the first diffraction order light.</p> |
