Focus control system for optical read-out apparatus

Details Focus control system for optical read-out apparatus Focus control system for optical read-out apparatus

1979-03-12

1981-01-06

Konick, Bernard

Dynamic information storage or retrieval

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

Mechanism control by the control signal

250202, 369112, 369124, G11B 712

Patent

active

042438489

ABSTRACT:
In a video and/or audio disc player wherein a laser beam is focused by an objective on a record disc for scanning same along a spiral information track thereon, a focus control is provided which comprises a converging lens disposed across the path of the information-modulated laser beam. Two or three photodetector elements are disposed on one of the conjugate planes of the converging lens the other of which substantially coincides with a focal plane of the objective. Aligned in the direction in which the successive images of pits on the record disc travel thereover, the photodetector elements produce electrical outputs having a phase relationship representative of the variable distance between record disc and objective. A focus control circuit produces an output signal corresponding to the phase relationship of the outputs from the photodetector elements, for delivery to a drive coil capable of electromagnetically moving the objective toward and away from the record disc for readjustment of the distance therebetween.

REFERENCES:
patent: 3932700 (1976-01-01), Snopko
patent: 3952191 (1976-04-01), Tinet
patent: 3969575 (1976-07-01), Gerritsen et al.
patent: 4025784 (1977-05-01), Lehureau et al.
patent: 4051527 (1977-09-01), Braat
patent: 4097730 (1978-06-01), Korpel
patent: 4165519 (1979-08-01), Goto

Affiliated with

Also associated with

Rating

Focus control system for optical read-out apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Focus control system for optical read-out apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Focus control system for optical read-out apparatus will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-286636