Discovision Associates

Mca Disco-vision, Inc.

James E Elliott

Lawrence S Canino

Lee Mickelson

A video signal play back device derives video signals from successive tracks formed as a continuous spiral on a video disc using a light source and a lens system, which is carried by a rotatable element at a predetermined spacing from the surface of the disc and which defines a folded optical path. The rotatable element translates the lens system in the radial direction relative to the disc for 'coarse' steering of the light beam along the information tracks as the disc is rotated by a turntable. The optical path includes a mirror which is articulated for rotational motion about an axis which shifts the point of impingement of the transmitted light beam upon the disc in the radial direction. The returned beam is directed to a photosensitive pick-up which provides input signals to a circuit which generates a 'fine' servo control signal to drive the articulated mirror.

Video disc head tracking apparatus

Video disc read back scanner

A video disc player assembly is described employing a fixed base member with a pair of fixed rails, and a movable carriage member employing a pair of linear bearing assemblies in engagement with said rails. A capstan and pulley assembly provides a means for moving the carriage member over the rails in the base member. A motor and spindle are mounted on the carriage for rotary driving of the video disc, a centering means is provided to accurately center the disc about the spindle, and a stabilization plate is provided adjacent and parallel to the rotating disc.

Video disc player

A video disc player assembly is described employing a fixed base member with a pair of fixed rails, and a movable carriage member employing a pair of linear bearing assemblies in engagement with said rails. A capstan and pulley assembly provides a means for moving the carriage member over the rails in the base member.

A video signal play back device derives video signals from successive tracks formed as a continuous spiral on a video disc using a light source and a lens system, which is carried by a rotatable element at a predetermined spacing from the surface of the disc and which defines a folded optical path. The rotatable element translates the lens system in the radial direction relative to the disc for 'coarse' steering of the light beam along the information tracks as the disc is rotated by a turntable. The optical path includes a mirror which is articulated for rotational motion about an axis which shifts the point of impingement of the transmitted light beam upon the disc in the radial direction. The returned beam is directed to a photosensitive pick-up which provides input signals to a circuit which generates a 'fine' servo control signal to drive the articulated mirror. In an alternative embodiment, a second articulated mirror is included for shifting the point of impingement of the light beam in the tangential direction, along the information tracks, for purposes of time base error correction. The radial position of the first articulatd mirror is monitored to control, with a phase shift equal to one-quarter revolution of the disc, tangential movement of the second articulated mirror.

A video disc player assembly is described employing a fixed base member with a pair of fixed rails, and a movable carriage member employing a pair of linear bearing assemblies in engagement with said rails. A stabilization plate is mounted on the movable carriage for movement therewith. A motor and spindle assembly is mounted on the stabilization plate. A portion of the motor and spindle assembly extends through axially aligned apertures in the stabilization plate and carriage and carries a videodisc mounting surface coplanar with the stabilization plate. A centering means is provided to accurately center the disc about the spindle. A releasable clamp rigidly engages the spindle and holds the videodisc against the mounting surface parallel to the stabilization plate. A motor and spindle are mounted on the carriage for rotary driving of the video disc, a centering means is provided to accurately center the disc about the spindle, and a stabilization plate is provided adjacent and parallel to the rotating disc.

An optical transducer having concentric radiant beam detectors for converting a radiant beam to electrical signals including a first axially placed detector with a second detector concentric therewith. In one embodiment, the detectors receive the radiant beam through an amplifying auxiliary lens. Changes in focus differentially affect the magnitude of the beam impinging on the individual detectors, resulting in corresponding changes in the individual detector outputs. A focusing system employing the transducer moves a focusing lens in response to the differential output of the individual detectors. The focusing system can be employed in a video disc reading system so that the video disc scanning beam is always focused precisely at the disc. An electrical difference circuit leading from the photo-detectors generates a driving signal to energize a lens-moving motor for shifting the focusing lens along the axis of the beam.

Optical transducer and focusing system

A focus detector includes apertured photodetectors which intercept a radiant beam. Changes in focus differentially affect the amount of radiation impinging on the detectors resulting in corresponding changes in their signal output.

Focusing system for videodisc player

A video signal play back device derives video signals from a track on a video disc using a light source and an optical path to a lens system which is supported by an air bearing at a predetermined spacing from the surface of the disc. The optical path includes a mirror which is articulated for rotational motion about an axis which shifts the point of impingement of the transmitted light beam upon the disc in the radial direction. The returned beam is directed to a single photosensitive pick-up which, provides input signals to a circuit which generates a 'fine' servo control signal to drive the articulated mirror. The air bearing member includes apparatus providing a bias force that varies with the radial displacement of the transducer assembly relative to the disc center.

Growing community of inventors

San Pedro, CA, United States of America

James E Elliott