| 摘要 |
PURPOSE:To provide the optical information reproducing device improved in recording density and a transfer rate. CONSTITUTION:Light emitted from a light source 32 is made to parallel beams by a collimate lens 34 and is made incident on a phase plate 36. The phase plate 36 has two areas divided into two in the track direction of an optical disk 44, and generates substantially a phase difference of pi between a light beam which is made incident on one area and a light beam which is made incident on the other area. The light which passes through the phase plate 36 passes through a deflection beam splitter 38 and a 1/4 wavelength plate 40, and is subjected to image formation on the recording surface of the optical disk 44 by an objective lens 42. A reflected light from the optical disk 44 is condensed by the objective lens 42, reflected by the deflection beam splitter 38, and thereafter, projected to a photodetector 50 by an image forming lens 46. The photodetector 50 detects the presence of pins as the lightness and darkness of an image formed on its surface. |
