Method and apparatus for detecting a focussing condition of an o

Details Method and apparatus for detecting a focussing condition of an o Method and apparatus for detecting a focussing condition of an o

1981-08-14

1983-12-20

Richardson, Robert L.

Dynamic information storage or retrieval

Control of storage or retrieval operation by a control...

Mechanism control by the control signal

250204, G01J 136, G11B 700

Patent

active

044221681

ABSTRACT:
A method and apparatus for detecting a focussing error signal of an objective lens with respect to a video disc on which a light beam emitted from a laser light source is to be focussed as a light spot by the objective lens. A light flux reflected by the video disc is made incident upon a detection prism surface which is set substantially at a critical angle with respect to peripheral light fluxes reflected by the video disc, and the peripheral light fluxes reflected by the reflection surface are separately received by two light receiving regions which are spaced apart from each other. The focussing error signal is derived as a difference between output signals from the two light receiving regions.

REFERENCES:
patent: 4123652 (1978-10-01), Bouwhuis
patent: 4296316 (1981-10-01), Tsuji et al.
patent: 4357533 (1982-11-01), Winslow
patent: 4358200 (1982-11-01), Heemskerk et al.

Affiliated with

Also associated with

Rating

Method and apparatus for detecting a focussing condition of an o does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Method and apparatus for detecting a focussing condition of an o, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for detecting a focussing condition of an o will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-111201