| 摘要 |
PROBLEM TO BE SOLVED: To provide a metal halide lamp having high light emission efficiency, and an illumination device restraining increase of lamp voltage during lighting, preventing the lamp from non-lighting, restraining respective lamps from scatter of lamp voltage. SOLUTION: A pair of electrodes 18 are arranged in a light-emitting tube 6 having an envelope made of translucent ceramics. lanthanoid group halide containing at least either cerium (Ce) or praseodymium (Pr), halide of sodium (Na), and halide of mercury (Hg) are sealed in the light-emitting tube, and a relation; L/D≥1 is fulfilled, wherein, D (mm) is an inner diameter of the light-emitting tube 6, and L (mm) is a distance between electrodes 18. COPYRIGHT: (C)2005,JPO&NCIPI |
