System and apparatus for cathodoluminescent lighting

摘要

Electron sources for a cathodoluminescent lighting system are disclosed. An electron source is a broad-beam reflecting-type electron gun having a cathode for emitting electrons and a reflector and/or secondary emitter electrode and no grids. An alternative electron gun has a cathode having a heater welded to a disk, the disk having an emissive surface on a side facing a dome-shaped defocusing grid and an anode. A lighting system incorporating the electron sources has an envelope with a transparent face, an anode with a phosphor layer to emit light through the face and a conductor layer. The system also has a power supply for providing from five to thirty thousand volts of power to the light emitting device to draw electrons from cathode to anode and excite a cathodoluminescent phosphor, and the electrons transiting from cathode to anode are essentially unfocused. A power-factor-corrected embodiment is also disclosed.