Photoelectric modulator with transparent electrostatic shields

Claim 1

A PHOTOELECTRIC MODULATOR COMPRISING FIRST AND SECOND PHOTOCELLS EACH HAVING AN ENVELOPE, A D.C. INPUT CIRCUIT AND A.C. OUTPUT CIRCUIT CONNECTED TO SAID PHOTOCELLS, EACH OF SAID PHOTOCELLS HAVING A LIGHT TRANSPARENT ELECTRICALLY CONDUCTIVE COATING ON A PORTION OF SAID ENVELOPE, ELECTRICALLY CONDUCTING GUARD SHIELD SURROUNDIN EACH OF SAID PHOTOCELLS AND ELECTRICALLY CONNECTED TO SAID COATINGS, FIRST AND SECOND GASEOUS DISCHARGE LIGHT SOURCES, SAID LIGHT SOURCES BEING RESPECTIVELY POSITIONED IN PROXIMITY TO SAID COATINGS ON THE ENVELOPES OF SAID FIRST AND SECOND PHOTOCELLS, AN A.C. ENERGIZING VOLTAGE ALTERNATELY CONNECTED TO SAID LIGHT SOURCES SO THAT SAID LIGHT SOURCES ARE ALTERNATELY ENERGIZED, ELECTRICALLY CONDUCTING GROUND SHIELDING INTERVENING BETWEEN SAID LIGHT SOURCES AND SAID ELECTRICALLY CONDUCTING GUARD SHIELDS, PORTIONS OF SAID GROUND SHIELDING ADJACENT SAID PHOTOCELLS BEING LIGHT TRANSPARENT AND ELECTRICALLY CONDUCTING, SAID GUARD SHIELDS AND SAID GROUND SHIELDING BEING ELECTRICALLY ISOLATED SO THAT SAID PHOTOCELLS AND SAID D.C. INPUT CIRCUIT AND SAID A.C. OUTPUT CIRCUIT ARE ALL ISOLATED FROM THE A.C. ENERGIZING VOLTAGE FOR SAID LIGHT SOURCES.