| 摘要 |
PURPOSE: An LED device including a lifespan measuring system is provided to enable a user to easily grasp a lifespan of the LED device by comparing an initial light property value with a measured light property value. CONSTITUTION: An LED source emits light with a preset wavelength. A measuring unit(162) measures a light property value of the LED source and includes a light measuring unit, an MPD(Monitoring Photo Detector) and a photometer. A control unit(164) transmits an output signal by using the light property value measured by the measuring unit. A display unit(166) receives the output signal of the control unit and displays the output signal. |
