Method of screening a color image reproducing device

Abstract

Abstract THE SCREEN OF A THREE GUN SHADOW MASK TYPE OF COLOR CATHODE-RAY TUBE IS FORMED OF THREE INTERLEAVED SETS OF FILTERS, WITH THE FILTERS OF EACH SET PREDOMINANTLY TRANSMISSIVE OF AN ASSIGNED ONE OF THE PRIMARY COLORS GREEN, BLUE AND RED. THE FILTERS ARE CIRCULAR AND ARE OF SUCH DIAMETER THAT THEIR OUTER PERIPHERAL PORTIONS OVERLAP, LEAVING A CENTRAL SECTION OF EACH FILTER FREE TO ACCEPT A PHOSPHOR THAT EMITS LIGHT OF A WAVELENGTH FOR WHICH THE ASSOCIATED FILTER IS PREDOMINANTLY TRANSMISSIVE. THE SCREEN, IN EFFECT, HAS A MULTIPLICITY OF ELEMENTAL PICTURE AREAS GROUPED TO FORM COLOR TRIADS AND INDIVIDUALLY SURROUNDED BY A FILTER THAT ATTENUATES SUBSTANTIALLY ALL VISIBLE LIGHT. SCREENING IS ACCOMPLISHED WITH PHOTOSENSITIVE COATINGS THAT ARE SELECTIVELY EXPOSED BY ACTINIC ENERGY PROJECTED THROUGH THE SHADOW MASK. EACH SUCH EXPOSURE DEVELOPS AN IMAGE OF ONE SET OF FILTERS WHICH IS THEN DEVELOPED. THIS PROCESS IS CONDUCTED FOR EACH OF THE THREE COLORS TO DORM THREE SETS OF FILTERS WITH OVERLAPPING PERIPHERAL PORTIONS. THEREAFTER OR ESSENTIALY AT THE SAME TIME, THE PHOSPHOR MATERIALS ARE DEPOSITED WITH THE EMISSION OF EACH PHOSPHOR MATERIAL PROPERLY CORRELATED COLORIMETRICALLY WITH THE FILTER OVER WHICH IT IS SUPERPOSED.

Inventors

• 👤 Howard G Lange

Bibliographic Details