GB1308899A - Matrix hole type colour television receiving tube - Google Patents

Abstract

1308899 Colour television tubes TOKYO SHIBAURA ELECTRIC CO Ltd 15 Oct 1971 [15 Oct 1970] 48139/71 Heading H1D A matrix hole-type colour TV receiving tube comprises a funnel and curved faceplate, the faceplate inner surface being provided with a plurality of valleys and hills, a plurality of matrix holes formed on same, and a plurality of phosphor dots (8) overlying the matrix holes (6), (Fig. 2, not shown), wherein in an X-Y co-ordinate system with the Y axis perpendicular to the outer surface of the glass plate, the distance along the X axis between two adjacent points on a curve along the surface contained in a plane including both X and Y axes is from 10 to 50 Á, and the distance between the two points along the Y axis is 2 to 5 Á, the dY/dX at the two points being zero. The glass surface between the phosphor dots may be coated with a black coating material. The inner surface of the defined geometry ensures true circular matrix holes promoting white uniformity characteristics and image clearness is enhanced, and the resin being more uniformly exposed, as discussed in respect of Fig. 5 (not shown). The black coating is prevented from remaining on the hills. The surface dimensions may be selected by the mould-coarseness, heating temperature, moulding pressure and the rate at which the glass is added to the mould. The screen may be fabricated by applying a p.v.a. photosensitive resin, a Hg lamp illuminating same via a shadow mask (Fig. 7, not shown) in a three step process for each colour, at each step resin being light exposed selectively. Black coating material such as graphite is applied to cover the resin dots, and the surface dipped in an aqueous solution of hydrogen peroxides to dissolve the resin dots with the associated black layer, warm water spray enhancing the removal. Subsequently, the phosphor dots are formed by conventional photographic-mask procedures using phosphor layers with photoresist at each stage. The phosphor dot diameter is slightly larger than the matrix holes. The funnel and faceplate may be fused by a low m.p. binder. R.G.B. dots are instanced.