Hiromi Kanai

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.

A new high performance color picture tube the mask-focusing color tube

From a technical point of view improvements of color picture tube could be regarded as having reached their limits. In this respect we have found that the mask focusing tube can achieve this objective when they are combined with the black matrix technique, the high performance gun, dot screen structure, high matrix transparency and large electrode diameter. Two fold improvements of brightness and contrast have been obtained with two fold mask transparency, 22% higher matrix transparency and mask-focusing. 20–30% less deflection power, 70% less mask doming also have been achieved with 110 degree 36.5 mm neck diameter and 1∶2 mask focusing voltage ratio. 20% less spot diameter and sharp beam distribution have been obtained by new multi-stage focusing electron gun and delta arrangement 36.5 mm neck diameter.

The New Brighter Mask-Focusing Picture Tube and its Peripheral System

In a color TV receiver employing a conventional shadow mask picture tube, only about a quarter of the emitted electron beams are used to energize the phosphor screen. For this reason, we have often experienced insufficient brightness with a large-screen color TV receiver. Phosphor material has been improved and the super black martix system has been devised to increase the brightness. These means, however, do not necessarily produce satisfying results. And if we want a brighter large-screen TV receiver, we must increase the high-voltage power.