| 摘要 |
PROBLEM TO BE SOLVED: To provide an LED illumination lamp capable of keeping constant brightness for a long term by managing total sum of lighting time and dimming an LED illumination lamp according to the cumulative time.SOLUTION: The passage of lighting time of LED light-emitting elements of each LED illumination lamp is calculated and stored, and reduction in light intensity of the LED illumination lamp is corrected, then the LED illumination lamp is lighted at reset brightness. In the passage of the lighting time at an initial stage, lighting life is extended by limiting a lighting current and delaying deterioration of light intensity. Moreover, the LED light-emitting elements of the LED illumination lamp are mounted to make them face the light-emitting direction to the whole spherical surface, and a control circuit capable of calculation is built in. |
