| 摘要 |
PURPOSE:To obtain a discharge lamp with improved starting characteristics by providing a main discharge path that performs main discharge between electrodes and a shortcircuiting discharge path that performs shortcircuiting discharge between electrodes, while specifying the relation between the path length of the discharge path and the cross-sectional area. CONSTITUTION:This discharge lamp consists of a U-shaped bent main discharge tube 10, a shortcircuiting tube 11 provided on the side of both ends of the discharge tube 10, and electrodes 12 and 13 provided in the discharge tube 10 near both openings 11a and 11b of the shortcircuiting tube 11. Besides, supposing that the path length of main discharge A generated in the discharge tube 10 is LA, the cross-sectional area of the discharge tube 10 is SA, the shortcircuiting B path length generated in the shortcircuiting tube 11 is LB, and the cross-sectional area of the shortcircuiting tube 11 is SB, the discharge lamp is arranged in the relation specified in EquationsIand II. Thus, together with the application of power supply, discharge is started in a shorter shortcircuiting discharge path. Thereafter, the when voltage maintained in shortcircuiting discharge becomes fully higher than the voltage maintained in main discharge in the main discharge path, only the main discharge is further performed in the main discharge path and state of stationary discharge is established. As a result, discharge starting characteristics can be improved. |
