Abstract: A system and apparatus is disclosed for retrieving analog or digital information stored on an optically sensed disc. In a preferred embodiment, a video disc is disposed between a flooding light source and a matrix array of photosensitive elements, there being provided optical focusing means so that the illuminated data tracks of the video disc are imaged onto the photosensitive array. Circuitry is provided for sensing output signals from selected elements of the array and in response thereto selecting those elements of the array onto which the selected track (or tracks) is best imaged. In this manner the apparatus of the present invention can provide data track following, conventional data retrieval and parallel simultaneous and sequential data retrieval. Alternative circuitry provides signal stream manipulation to compensate for fluctuations in rotational velocity of the data disc and to provide improved signal-to-noise ratios as well as frequency response enhancement.

Abstract: TV playback apparatus and method for a record having track sets comprising video track analogs and a plurality of audio track analogs disposed between the video tracks. All tracks in a respective track set are sensed for playback by a movable reading head incorporating a combination of video and audio sensing elements and including tracking of homing elements flanking the video reading element. A track set switching signal is sensed from the audio signal by an audio reading element for a controller means which very quickly slews the reading head to roughly position the video reading element for next video track. Such video track is sensed by any reading element in the reading head and determined through a multiplexer and controller means. Reading head is further stepped as necessary until video track sensing element is reading video track as controller receives video signal through band pass filter video sensing element.

Abstract: A system for sensing information located in tracks in various layers or depths of a recording medium. The desired information is electro-optically tracked in three dimensions to provide sensing of the information contained in the multi-layered recording medium.