Optical information reading apparatus comprising a diffraction g

Details Optical information reading apparatus comprising a diffraction g Optical information reading apparatus comprising a diffraction g

1989-04-07

1991-09-10

Envall, Jr., Roy N.

Dynamic information storage or retrieval

With servo positioning of transducer assembly over track...

Optical servo system

369112, 369109, 369100, 2502051, 35011617, 356124, G01J 120, G11B 700

Patent

active

050480006

ABSTRACT:
An optical information reading apparatus for reading recorded information by detecting the presence or absence of pits on an optical disk using a laser beam. The laser beam converged a lens irradiates the optical disk in the form of light spots when in the in-focus state. A dividing line of a holographic grating used for detecting offset of the lens from the in-focus state and a dividing line of a photosensitive detector receiving a light diffracted by the holographic grating are adapted to as to be parallel to a radial direction of the optical disk. Therefore, when a light spot formed on the optical disk by astigmatism of the lens assumes an elliptical shape, the light spot becomes an ellipse whose long axis extends to the direction of the dividing line of the photosensitive detector, so that no error signal is generated in the in-focus state.

REFERENCES:
patent: 3913076 (1975-10-01), Lehureau et al.
patent: 4733065 (1988-03-01), Hoshi et al.

Affiliated with

Also associated with

Rating

Optical information reading apparatus comprising a diffraction g does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Optical information reading apparatus comprising a diffraction g, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Optical information reading apparatus comprising a diffraction g will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-546028