Penetration phosphors and display devices
AssigneeSperry Rand Corporation
InventorStanley F. Ignasiak
Life of this patent
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Abstract
La.sub.2 O.sub.2 S particles are employed as carrier hosts in a cathodo-luminescent penetration phosphor composition for cathode ray display tubes. Tb and Eu ions are used in low concentrations as activators in the control of the red and green optical emission from within a film of the activated host material.
Claims20
An electron tube including an evacuated envelope, a cathodo-luminescent screen therein, and means for exciting said screen within said envelope by electrons, said screen including cathodo-luminescent particles each comprising:
- a generally central region, and
- a generally peripheral region surrounding said central region in contiguous relation therewith,
- said particle being composed of a La phosphor material with a substantially uniform distribution of Tb ions, and
- said generally peripheral region having a distribution of Eu ions increasing toward the exterior surface of said particle,
- said La phosphor material being La.sub.2 O.sub.2 S,
- said Tb ions being provided by Tb.sub.2 O.sub.2 S,
- said Eu ions being provided by Eu.sub.2 O.sub.2 S, and the respective concentrations of Tb.sub.2 O.sub.2 S and Eu.sub.2 O.sub.2 S each being substantially smaller than the concentration of La.sub.2 O.sub.2 S.
An electron tube including an evacuated envelope, a cathodo-luminescent screen therein, and means for exciting said screen within said envelope by electrons, said screen having cathodo-luminescent particles each comprising:
- a generally central region composed of a La.sub.2 O.sub.2 S :
- Tb.sub.2 O.sub.2 S phosphor,
- a generally peripheral region surrounding said central region in contiguous relation therewith composed of La.sub.2 O.sub.2 S :
- Tb.sub.2 O.sub.2 S :
- Eu.sub.2 O.sub.2 S phosphor,
- the La.sub.2 O.sub.2 S and Tb.sub.2 O.sub.2 S materials being substantially uniformly distributed in said particle and the relative concentrations of said Tb.sub.2 O.sub.2 S and said Eu.sub.2 O.sub.2 S being such that relatively low velocity electrons striking any one of said particles excite said phosphor in said peripheral region preferentially to produce red line emission, and relatively high velocity electrons striking one of said particles excite said phosphor in said central region preferentially to produce green line emission.
Dependencies are inferred from the claim text.