| 摘要 |
PURPOSE:To obtain color temperature which is harmonious with an incandescent lamp or the like by specifying the relationship between the area of the cross section of a metal foil conductor at the electrode-sealing part and the electric power of a lamp as well as the relationship between the distance between the inner ends of the emission tube and its whole length. CONSTITUTION:In a metal halide lamp the internal volume of the emission tube of which is below 1c.c, the area (Smm.<2>) of the cross section of a molybdenum foil conductor 4 at the sealing part 2 of an electrode 3 is adjusted to 0.1XP<=S<= 0.4XP+4 relative to the electric power (P wat) of the lamp. In addition, the ratio (M/L) of the distance (M) between the inner ends of the emission tube to its whole length (L) is restricted to 3.5X10<-1M/L<4.7X10<-1>. As a result, loss caused by the thermal conduction of the sealing part 2 is reduced without deteriorating the sealing function of the molybdenum foil 4 thereby increasing the temperature of the coldest part. Consequently, the color temperature of such a lamp can be made almost equal to that of a fluorescent lamp. Besides, such a lamp can be used in substitution for or in combination with a fluorescent lamp. |
