HIGH-PRESSURE DISCHARGE LAMP AND LIGHTING METHOD OF THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a high-pressure discharge lamp capable of preventing a significant blackening from being generated in an inner wall of a luminous tube part while maintaining a lighting state in which mercury is precipitated (condensation) in the luminous tube part and a lighting method of the same.SOLUTION: A high-pressure discharge lamp 10 is constituted of a luminous tube part 12 having an inner space 16; a pair of tungsten electrodes 20 oppositely disposed in the inner space 16; and mercury 24 and halogen 26 encapsulated in the inner space 16. The halogen 26 is encapsulated excessively relative to a capacity of the inner space 16 so that a proper halogen cycle is formed when part of the mercury 24 is precipitated without being evaporated.