A new high-performance color picture tube: The mask-focusing color tube

From a technical point of view, improvements of conventional color picture tubes could be regarded as having reached their limits. In this respect, we have found that the mask-focusing tube can achieve further improvements when combined with the black-matrix technique, a high-performance gun, dot screen structure, high-matrix transparency, and large gun electrode diameter. Two-fold improvements of brightness and contrast have been obtained with mask transparency twice that of conventional tubes, 22-percent higher matrix transparency, and mask-focusing. A 20-30 percent less deflection power has also been achieved with 110° deflection, neck diameter, and 1:2 mask-focusing voltage ratio. A 20-percent less spot diameter and a sharp beam distribution have been obtained by a new multistage-focusing electron gun in a delta arrangement in the 35.5-mm neck diameter.