Method of producing a color picture tube screen
AssigneeU.S. Philips Corporation
InventorJan van der Waal
Life of this patent
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Abstract
A method of producing a color picture tube screen particularly for a high definition tube. In producing a high definition screen light from a point source (S) is directed through a segmented lens (18) and a shadow mask (24) onto a layer of photoresist applied to the internal surface of a faceplate panel (12). The segmented lens (18) comprises a rectilinear array of differently inclined facets (F). In order to obtain a substantially uniform illumination of the faceplate panel (12), the segmented lens (18) is wobbled in an oblique direction such that in moving from one extreme position to another, the image of a facet on the panel occupies substantially the previous position of the image of another facet obliquely adjacent the first mentioned facet when at the one extreme position.
Claims9
A method of producing a colour picture tube screen, comprising exposing a photosensitive material on a faceplate panel to light emitted by a point light source and passed through a segmented lens, the segmented lens comprising an array of facets at least two of the facets being inclined at different angles, and simultaneously changing the relative position between the segmented lens and the faceplate panel in a direction oblique to the boundaries of the facets during exposure of the photosensitive material, wherein the extent and direction of changing the relative position between the segmented lens and the faceplate panel is such that in moving from one extreme position to another extreme position, the image of a facet on the panel occupies substantially the previous position of the image of another facet obliquely adjacent the first mentioned facet when at the one extreme position.
Dependencies are inferred from the claim text.