Screening a black-surround color cathode-ray tube

Abstract

Abstract THE SCREEN IS COVERED WITH SENSITIZED PVA AND EXPOSED FROM EACH OF THREE POSITIONS SIMULATING THE THREE BEAMS OF THE TUBE IN PROCESS BUT WITH THE EXPOSURE POSITIONS DISPLACED INWARD TOWARD THE TUBE AXIS IN THE PLANE OF DEFLECTION. THE LATENT IMAGE THUS PRODUCED ON THE SCREEN IS THEN DEVELOPED AND LIGHT-ABSORBING MATERIAL IS DEPOSITED IN THE PORTIONS OF THE SCREEN FROM WHICH UNEXPOSED PVA HAS BEEN REMOVED IN THE DEVELOPING STEP. THE SCREEN IS THEN STRIPPED OF THE REMNANT PVA LAYER AND AGAIN COATED WITH PVA. THEREAFTER, A SIMILAR EXPOSURE IS UNDERTAKEN BUT NOW WITH THE EXPOSURE POSITIONS DISPLACED OUTWARDLY FROM THE TUBE AXIS IN THE PLANE OF DEFLECTION. FOLLOWING THE THIS THERE IS A FURTHER DEVELOPMENT STEP AND AGAIN THE DEPOSITION OF LIGHT-ABSORBING MATERIAL ON THE PORTIONS OF THE SCREEN FROM WHICH PVA HAS BEEN REMOVED. THE THREE EXPOSURE POSITIONS IN EACH OF THESE TWO SEQUENCES OF PROCESS STEPS CAUSE THE MATRIX, WHICH IS MADE IN TWO SEGMENTS, TO EXHIBIT APPROXIMATELY CIRCULAR HOLES PROPERLY LOCATED TO RECEIVE PHOSPHOR AND FORM THE CUSTOMARY PHOSPHOR DOT TRIADS ON THE SCREEN OF THE TUBE.

Inventors

• 👤 Sam H Kaplan

Bibliographic Details