Abstract The screen of a shadow mask type of tricolor picture tube is coated with a light-absorbing layer comprising a composition of a black inorganic pigment material, an acrylic binder and a solvent therefor, specifically toluene. After drying, this layer is overcoated with polyvinyl alcohol and dichromate in water as a solvent and the overcoat is exposed by ultraviolet light, leaving unexposed elemental areas of dot shape. The overcoat is treated with water which removes the unexposed portions and uncovers the corresponding portions of the light-absorbing coating and these portions of the last-mentioned coating are removed by treating with toluene. As a result, elemental dot areas of the screen, which are assigned to one of three phosphor materials, are now laid bare. The exposed elemental portions of the polyvinyl alcohol coating are stripped and all the process steps, except for forming the light-absorbing layer, are repeated two more times, preparing additional elemental screen areas to receive phosphor deposits. The three phosphor materials are then applied in conventional manner.
The method in accordance with claim 1 in which: the sequence of steps (b) through (f) is performed for each of said phosphor materials.
Claim 2
Dependent Claim
49 words
The method in accordance with claim 1 in which said light-absorbing layer is formed of a composition including an ingredient that has light-absorbing capabilities, an acrylic resin binder and a solvent for said binder; and in which step (e) comprises treating said screen with said solvent for said binder.
Claim 3
Dependent Claim
41 words
The method in accordance with claim 3 in which said ingredient of said light absorbing layer is manganous carbonate; And in which, following step (i), said screen is subjected to a heat treatment to convert said manganous carbonate to manganese dioxide.
Claim 4
Dependent Claim
40 words
The method in accordance with claim 3 in which said light-absorbing layer is insoluble in said solvent for said photosensitive layer; and in which said exposed photosensitive layer is insoluble in said solvent for said binder of said light-absorbing layer.
Claim 5
Dependent Claim
32 words
The method in accordance with claim 1 in which said phosphor materials are deposited by photographic printing employing said electrode as an image-defining pattern in the application of each of said phosphors.
Claim 6
Dependent Claim
320 words
In the manufacture of a color image reproducing device having a spherically shaped screen and having a color-selection electrode comprised of a mask having a field of circular apertures, the method of fOrming on said screen a multiplicity of interleaved sets of dot-shaped deposits of different phosphor materials that are separated from one another by light-absorbing material and are smaller in size than said apertures of said masks, which method comprises the following steps: a. coating the inner surface of said screen with a layer of material which has the capability of substantially absorbing ambient light and which is soluble in a first predetermined solvent; b. applying thereover a layer of photosensitive material which is insoluble in said first solvent and which may be rendered insoluble in a second predetermined solvent in response to exposure to actinic energy; c. directing actinic energy from a source through the apertures of said electrode to expose and insolubilize a series of ring-shaped portions of said photosensitive layer individually enclosing an unexposed elemental area which is smaller in size than the apertures of said electrode and which overlays a corresponding elemental area of said screen assigned to a particular one of said phosphor materials; d. treating said screen with said second solvent to remove said unexposed portions of said photosensitive layer and to uncover the portions of said layer of light-absorbing coating that overlay said corresponding elemental areas of said screen; e. treating said screen with said first solvent to remove said uncovered portions of said layer of light-absorbing coating; f. stripping said exposed portions of said photosensitive layer from said screen; and g. repeating the sequence of steps (b) through (f) for remaining ones of said phosphor materials but with the position of said source modified to leave unexposed in each such sequence the portions of said photosensitive layer overlaying elemental areas of said screen assigned to another one of said phosphor materials.