| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a metal halide lamp of a mercury-free type wherein occurrence of a glare caused by a fish-eye to inevitably occur accompanied with aging can be prevented. <P>SOLUTION: This has a light-permeating bulb 4, a pair of electrodes 5, a discharge medium substantially not containing the mercury, and a mark 9. A bulb 4 is provided with the inner tube 2 in which the fish-eye 12 exists in the inner bottom face 2c of a wall 2a prescribing a discharging space 11, and the outer tube 3 arranged at the outer side of the inner tube 2. A pair of electrodes 5 makes one end parts protruded into the discharging space 11 oppose, and is installed in the inner tube 3. The discharging medium contains a metal halide 6 adhered to the inner bottom face 2c in which the fish-eye 12 exists in non-lighting, and contains a rear gas, and is sealed in the discharging space 11. The mark 9 related with the position of the fish-eye 12, is installed at the outer tube 3, and prescribes the utilizing direction of a light as the upward one. The mark 9 is used as a criterion to reverse nearly 180° around the shaft line from the horizontal lighting posture in aging the lamp 1. <P>COPYRIGHT: (C)2004,JPO |
