Optical communication and display system

Claim 1

In a system of the type in which deflecting means scans a light beam applied thereto, which light beam is intensity-modulated with video information manifesting a given scene, comprising translating means coupled to said deflecting means and responsive to received light wave energy from a remotely located source applied as an input thereto which light wave energy as received is modulated in some given form with a video signal manifesting both said given scene and sync signals for synchronizing the scan of said deflecting means, said translating means including means for employing said received light wave energy as the wave energy of said light beam, obtaining said intensity modulation of said light beam from said given form of modulation of said received light wave energy, and separating said sync signals from said received light wave energy and applying them to said deflecting means to synchronize the scan thereof, the improvement: wherein said given form of modulation comprises a subcarrier modulated by the video signal of said light wave energy, the entire bandwidth of said modulated sub-carrier being above the highest baseband frequency component of said video signal itself, and wherein said translating means comprises means including a photodetector for demodulating only a portion of said light wave energy, an electro-optic modulator having the remainder of said light wave energy applied as an input thereto, means coupled to said photodetector including a sub-carrier detector responsive to the output of said photodetector for reducing said video signal to baseband, sync separator means for removing said sync signals from said baseband video signal, said baseband video signal being applied as a modulating signal to said electro-optic modulator and said separated sync signals being applied to said deflecting means to synchronize the scan thereof, the output from said electro-optic modulator constituting said light beam applied to said deflecting means.