Title:
OPTICAL INFORMATION REPRODUCING DEVICE AND ITS RECORDING MEDIUM
Document Type and Number:
Japanese Patent JP3021825
Kind Code:
B2
Abstract:
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 π 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.
Inventors:
Jun Kanehira
Application Number:
JP22743991A
Publication Date:
March 15, 2000
Filing Date:
September 06, 1991
Export Citation:
Assignee:
Olympus Optical Co., Ltd.
International Classes:
G11B7/00; G11B7/005; G11B7/007; G11B7/135; G11B7/14; G11B7/24; (IPC1-7): G11B7/005; G11B7/007; G11B7/135; G11B7/14; G11B7/24
Domestic Patent References:
| JP341622A | ||||
| JP3104021A | ||||
| JP6488922A | ||||
| JP61126635A | ||||
| JP57138065A | ||||
| JP6350933A | ||||
| JP2201750A | ||||
| JP2185732A |
Attorney, Agent or Firm:
Takehiko Suzue
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