Cathode ray tube screen exposure system

An improvement in an exposure system for photo-forming a stripe-patterned screen for an in-line gun color cathode ray tube, said system utilizing a defined linear source of radiant energy for selectively photoexposing the sensitized inner surface of the tube viewing panel through a spatially related multi-opening mask member and a conjunctively positioned light refractive medium, said improvement relating to adjustable means for predeterminately oscillating said source of radiant energy, said means comprising:

• a substantially planar control disk having a fixed center shaft therethrough, and evidencing a multitude of similar equi-spaced index apertures arranged in an orderly arcuate linear manner near the periphery thereof, and at least one control aperture oriented near said linear arrangement of index apertures but not in linear relationship therewith;
• a positionally-adjustable reset probe in the form of a photo-sensing unit oriented at a location adjacent said disk to respond to associated light energy beamed through said disk control aperture thereby providing controlling electronic pulses;
• a positionally-adjustable index probe in the form of a photo-sensing unit oriented at a location adjacent said disk spatially removed from said reset probe, said index probe being in a position to respond to associated light energy beamed through said index apertures as they move thereacross thereby providing index electronic pulses;
• a cam member associated with said control disk and affixed to said center shaft at a position adjacent said control disk, said member having a definitive surface of discretely shaped contour;
• cam follower means formed to mate with said cam contour in a manner to translate cam motion into reciprocating movement;
• slide means and companion support means positioned relative to said cam follower and fashioned to accommodate said source of radiant energy, said slide being attached to said cam follower means to receive the reciprocating movement imparted therefrom;
• motor means attached to said center shaft to provide a degree of rotary motion thereto;
• and
• electric power source means and associated electronic control circuitry, said circuitry reading the input of said controlling and index electronic pulses from said probes with reference to adjustable index counting means and related switching control means, said circuitry effecting controlled rotary movement of said motor and related disk and cam members with repetitive reversal of directional rotation thereof, thereby achieving predetermined oscillation of said radiant energy source.