US 5,121,030 AGranted

Absorption filters for chlor display devices

AssigneeHoneywell Inc.

InventorDan J. Schott

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Abstract

A contrast enhancement filter for color displays, particularly adapted for color CRT tubes of the shadow mask type. A transparent plate has applied thereon absorptive areas, each area dyed with a primary color corresponding to the color dots of the CRT display face and a plurality of such color areas randomly disposed over each color dot. Since the absorption areas are spacially independent, each color area acts independently of the others. The filter provides bandpass efficiency comparable to monochrome filters, and has a broad viewing range essentially independent of angle of vision. In a further embodiment, colored oriented fiber-optic elements are disposed over the phosphor dots in a predetermined array, allowing the filter plate to replace a conventional faceplate and filter combination structure, while providing a selective viewing angle of high contrast. The filter is suitable for any light-responsive display screen, also including liquid crystal elements.

Claims8

Dependent claims

An optical filter for contrast enhancement of a color display, said display comprising a light-responsive layer having a plurality of discrete elements, each of said elements adapted for emitting or transmitting light in a predetermined primary color wavelength, said optical filter comprising:

an optically transparent substrate adapted for superposition over said light-responsive layer, and having a plurality of colored areas arranged in clusters of at least one primary color superposed over each of said discrete elements, each of said plurality of colored areas so constructed and adapted to transmit selectively a narrow band color spectrum corresponding to at least one said predetermined primary color wavelength of said discrete elements and substantially to absorb color wavelengths other than said one predetermined primary color wavelength, and wherein each of said discrete elements is further associated with a multiplicity of colored areas of a given color transmissibility, areas of a given primary color transmissibility being illuminated when the underlying discrete element is activated by a source of electrical energy.

Dependencies are inferred from the claim text.