| 摘要 |
PROBLEM TO BE SOLVED: To provide a lighting device without generating sway in the light emitted therefrom, without flicker on an irradiating face, having a discharge lamp free from fading away. SOLUTION: The lighting device has both a discharge lamp 1 and a lighting circuit 4 housed in a same casing 5. Provided that a lighting frequency of the lighting circuit is f(kHz), the lighting frequency f(kHz) is defined by formula: 0.95×(nV/2L)≤f≤1.05×(nV/2L) äwhere, n is a natural number (n=1, 2, 3 etc.), V is the velocity of sound (440m/s), L is an inner diameter (m) of a luminous tube in a direction passing the center between the electrodes of the discharge lamp and orthogonally crossing the electrode axis}. COPYRIGHT: (C)2004,JPO |
