Slide projection control system

Claim 1

IN COMBINATION WITH A PAIR OF SLIDE PROJECTORS EACH HAVING A SLIDE CHANGING MECHANISM AND A PROJECTION LAMP FOR ALTERNATIVELY PROJECTING IMAGES ONTO A COMMON SCREEN AREA, A PROGRAMMING DEVICE PRODUCING SLIDE CHANGEOVER PULSES SYNCHRONIZED WITH AUDIO OUTPUT SIGNALS, PULSE CONTROLLED MEANS OPERATIVELY CONNECTED TO SAID SLIDE CHANGING MECHANISMS FOR OPERATION THEREOF IN RESPONSE TO SAID CHANGEOVER PULSES, MEANS OPERATIVELY CONNECTED TO SAID PROJECTION LAMPS FOR SIMULTANEOUSLY DIMMING ONE OF THE LAMPS AND ILLUMINATING THE OTHER OF THE LAMPS DURING A CHANGEOVER CYCLE OF THE PULSE CONTROLLED MEANS, DISSOLVE CONTROL MEANS RESPONSIVE TO THE DURATION OF SAID PULSES FOR CONTROLLING THE TIME INTERVAL DURING WHICH SAID LAMPS ARE RESPECTIVELY DIMMED TOWARD EXTINCTION AND ILLUMINATED TOWARD MAXIMUM BRILLIANCE, CURRENT CONTROL MEANS CONNECTED IN SERIES WITH EACH LAMP AND RENDERED CONDUCTIVE FOR UNIDIRECTIONALLY LIMITING FLOW CURRENT TO A MINIMUM VALUE MAINTAINING, THE LAMPS HEATED WITHOUT INCANDESCENCE, AND MEANS CONNECTED TO THE CURRENT CONTROL MEANS FOR RENDERING THEREOF CONDUCTIVE TO VARY THE VOLTAGE ACROSS THE LAMPS IN OPPOSITE DIRECTIONS AT NON-LINEAR RATES OF CHANGE PREVENTING IMAGE REDDENING DURING SAID TIME INTERVAL.