Laminated filter-electroluminescent recitular index for cathode ray display
AssigneeSperry Rand Corporation
InventorsJames B. Armstrong, J. Robert Trimmier
Life of this patent
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Abstract
An optical filter possessing narrow pass band characteristics selectively absorbs impinging ambient white light components and is used in combination with a laminate graticule having transparent electrodes lying in a common plane for defining a multiplicity of electrically insulating gaps in the pattern of the graticule for exciting associated partially over-lying electroluminescent phosphor patterns. The graticule pattern being composed of an electroluminescent material, night viewing of the graticule is readily accomplished by electrically exciting it. For daylight viewing, the unexcited phosphor material is itself directly viewed.
Claims20
Bright image display apparatus of the cathode ray tube having a viewing face with a predetermined spectral emission characteristic when energized comprising:
- contrast enhancement filter means on said viewing face having an optical band pass related to said predetermined spectral emission characteristic for absorbing scattered light emissions from said viewing face and rendering said image readily visible under high and low ambient light conditions,
- graticule index means associated with said filter means comprising first and second electrode means, at least one of said electrode means being transparent and at least one of said electrode means forming narrow gap means with the other electrode means, said gap having a predetermined generally lineal graticule pattern,
- electroluminescent means disposed within said gap means, said electroluminescent means having a reflectance characteristic rendering it visible by reflected light under high ambient light conditions, and
- means for applying a voltage between said transparent electrode means for exciting said electroluminescent means and rendering said graticule pattern visible under low ambient light conditions.
Bright image display apparatus having a viewing face and a predetermined optical emission spectrum comprising:
- contrast enhancement filter means disposed on said viewing face for transmitting a predetermined portion of said optical emission spectrum and for absorbing scattered light lying outside of said portion,
- transparent graticular index means disposed on said contrast enhancement filter means at a common interface,
- at least first and second transparent electrode means disposed at said common interface on said transparent graticular index means for forming lineal gap means therebetween, and
- electroluminescent means disposed within said lineal gap means thereby forming lineal index means,
- said lineal index means being adapted to selective viewing by application of a voltage between said first and second transparent electrode means for viewing said electroluminescent means in electrically excited state or by removal of said voltage for direct viewing of said electroluminescent means by ambient light reflected therefrom.
Dependencies are inferred from the claim text.