| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a metal halide lamp free from cracks at a pinch seal part of an inner tube. <P>SOLUTION: The metal halide lamp has a double-tube structure 42 containing an arc tube in an inner tube with its one end pinch-sealed and held by a holder 102 inside an envelope consisting of an outer tube and a case. The arc tube has a pair of electrodes inside, and a pinch seal part 78 of the double-tube structure 42 is held by a holding hole of the holder 102. Out of positions where an outer periphery face of the holder 102 is in contact with an inner periphery face of the outer tube, when the nearest position from a tube axis Y of the arc tube is point A, and a diameter of a circle passing the point A around a point on the tube axis crossing a tube axis Y is D, a distance L (a direction going away from the holder 102 is to be positive) of the point A against a reference face X passing a center O between the electrodes and crossing the tube axis Y satisfies: L≤0.25×D+0.14×Wla-21 (Wla:lamp power). <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
