LUMINESCENT PHOTOCATHODE LIGHT SOURCE Russian patent published in 2000 - IPC

FIELD: high- brightness light sources. SUBSTANCE: light source has evacuated bulb with transparent screen carrying conductive layer that functions as anode. Conductive layer is coated with phosphor. Planar photocathode is mounted inside bulb opposite to conductive layer. Phosphor has at least two components. One of components provides for luminescence of visible beam and other one, radiation of ultraviolet beam whose wavelength is sufficient to ensure normal operation of photocathode. Proportion of these components is chosen so that current is self-maintained when definite voltage is applied between cathode and anode. Cathode should be made of material ensuring highest possible efficiency of photoemission without being poisoned by phosphor. Starting emitter may be placed inside bulb or at least one grid may be inserted between anode and photocathode. Cathode is usually polished component. Bulb may be filled with working gas. Gas pressure and field parameters should be optimal for starting ultraviolet radiation of working gas. EFFECT: improved efficiency of light source built around low-cost photocathodes. 5 cl, 1 dwg