Patent ID: 8148902

Claim:
A mercury-free arc tube for a discharge lamp device, the mercury-free arc tube comprising: a pair of electrodes; a pair of molybdenum foils connected to the electrodes, respectively; a pair of lead wires connected to the molybdenum foils, respectively; and a closed glass bulb in which luminescent substances other than mercury are enclosed and in which the pair of electrodes are opposed each other, a region of the electrodes including the molybdenum foil being pinch-sealed by glass, wherein the electrode, the molybdenum foil and the lead wire are integrated, and wherein the molybdenum foils comprise TiO 2 doped or coated in a discontinuous lands manner, and a surface which is etched by oxidation and reduction; wherein the molybdenum foils are TiO 2 coated in a discontinuous lands manner, and the ratio of the amount of TiO2 to the total area is 6 to 8 μg/cm 2 .