Patent ID: 6084351
Filing Date: 2000-07-04
Classification: H01J

Abstract:
A metal halide lamp which includes a discharge tube retaining a fill of mercury and at least one metal halide added as a luminous material in an inert gas atmosphere sealed therein, comprising:a pair of discharge electrodes oppositely disposed with a space of a gap distance defining a length of an arc discharge portion produced between the paired discharge electrodes in the discharge tube,wherein an energy density of the arc discharge portion represented by a product E.times.j is in the range of70.0.ltoreq.E.times.j.ltoreq.150.0 (VA/mm.sup.3)where E=V/d, j=I/S, assuming that I is a lamp current in amperes with a lamp voltage of V volts applied between the paired discharge electrodes in a stable lighting condition of the lamp and that each of the electrodes has a tip face of which a cut area in section is S mm.sup.2 and the gap distance is d in millimeters.