Patent ID: 7508133

Claim:
A hot-cathode type discharge lamp comprising: a glass tube having two electrodes with an electron emissive material coated thereon, each electrode including a heater composed of a filament or coil, said electrodes being provided in respective ends of said glass tube, wherein: said glass tube has a gas containing a luminescent material sealed therein, the luminescent material including mercury, said glass tube further includes a fluorescent material coated on its inner surface, said glass tube has a diameter less than 6.5 mm, said gas sealed into said glass tube is comprised of gases of more than one kind selected from an Ar (argon) gas, a Kr (krypton) gas and a Xe (xenon) gas, and including less than 50% of a Ne (neon) gas, and said sealed gas has a total pressure ranging from 10 to 60 Torr.