Discovision Associates

Mca Disco-vision, Inc.

Lee Mickleson

Eric V Olson

A servo control system for maintaining an information detection device, such as a light beam, at the optimum focused position above an information track for retrieving the maximum amount of reflected radiation from an information track, such as a spiral recording track on a videodisc. The system of the invention includes an optical system, a piezoelectric dither element, a dither oscillator, circuitry for deriving an intermediate signal indicative of the effect of the dither on the detected signal derived from the information track, phase comparison circuitry for deriving an error signal from a comparison of the dither signal applied to the piezoelectric dither element and the actual dither modulation of the light beam retrieved from the information track, and a movable lens assembly responsive to the error signal for accurately focusing the light beam upon an information track.

Dithered focusing systems

A servo control system for maintaining an information detection device, such as a light beam, centered on a moving information track, such as a spiral recording track on a video disc. The system of the invention includes an optical system, a piezoelectric dither element coated with a resistive material, a dither oscillator, circuitry for deriving an intermediate signal indicative of the effect of dither on the detected signal derived from the information track, phase comparison circuitry for deriving a known error signal from a comparison of the dither signal applied to the piezoelectric element and the actual dither modulation of the light beam retrieved from the information track.

Dithered center tracking system

A reproducing objective lens for videodiscs comprising five single lenses for which the working distance is large and flatness of field and resolving power are high.

Reproducing objective lens for videodiscs

A write and read objective lens for encoding and recovery of information upon a storage member comprising three single lenses and one achromatic doublet for which the working distance is large, flatness of field and resolving power are high and utilizable with a plurality of wavelengths of light.

Growing community of inventors

Long Beach, CA, United States of America

Lee Mickleson