Patent ID: 6897613

Claim:
A discharge lamp comprising: a light emitting bulb having two ends; a sealing member located at each of said two ends of said light emitting bulb; a pair of electrodes, one of which is sealed in each of said sealing members and located in said light emitting bulb opposing each other at a predetermined spacing; and a discharge medium enclosed in said light emitting bulb, wherein each of said electrodes comprises an electrode shaft and a discharge member integral with a tip of said electrode shaft and having an outside diameter larger than that of said electrode shaft, said discharge member having a taper formed on its tip, said electrode having a heat dissipating conductor located at an end opposite said discharge member and surrounding the electrode shaft, and wherein said discharge lamp satisfies the following conditions: φ/L≦0.6 20°≦θ≦60° where the reference symbol L denotes a spacing between said electrodes located in said light emitting bulb, the reference symbol φ denotes a diameter of the tip of the discharge member, and the reference symbol θ denotes an angle between said taper and said electrode shaft.