| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for turning on an optical device for a short arc metal halide lamp and a liquid crystal projector device using the optical device where the compression strain of the light emitting tube of a short arc metal halide lamp, especially, the compression strain or the tensile stress of an anode side electrode sealing part is restrained to reduce the mechanical fatigue of quartz glass caused by the flickering of the lamp. SOLUTION: This device is constituted of the short arc metal halide lamp which is equipped with a pair of electrodes 2a and 2b at both ends of a quartz tube, inside which at least mercury, rare gas and metallic halide are enclosed and where the light emitting tube 1 having single tube structure is arranged so that an arc axis may be horizontal; a concave reflection mirror 8 which is arranged to be combined with the short arc metal halide lamp and whose reflection surface 8 is constituted to be spherical, parabolic or ellipsoidal; and the optical device where the arc axis of the short arc metal halide lamp is positioned on the optical axis of the mirror 8 and which is DC-turned on. After starting up the short arc metal halide lamp, the rush current of the lamp after shifting from glow discharge to arc discharge is set to a value nearly equal to the value of a lamp current at the time when the lighting of the lamp is stable. |
