| 摘要 |
PROBLEM TO BE SOLVED: To effectively adjust the luminance without changing the voltage to be applied to a light-emitting element by adjusting the total outgoing energy of a surface light source by controlling a number of lighting of light-emitting elements. SOLUTION: An LED array 3 comprises the LEDs 3b arranged by 3 raws ×8 columns, and the lighting on and out of each LED 3b is controlled by a controller. The high driving voltage is applied to each LED 3b. For example, the outgoing luminance can be made half in comparison with a case when all of LEDs 3b are lighted, by lighting the LEDs 3b by each row and making the number of lighting of the LEDs 3b half. The lighting is optionally performed every line or zigzag. That is, by applying the vector radiation coupling type surface light generating source device, the distribution of the luminance of the outgoing light from the lighting system is hardly affected by the change of the in-plane distribution caused by the lighting of a part of LEDs 3b, and any lighting distribution of the LED array 3 can be applied. |
