| 摘要 |
<p>PROBLEM TO BE SOLVED: To highly accurately perform the life detection of a backlight by detecting the life of the backlight based on the luminance of the backlight and the resistance value of a luminance adjusting resistance so as to prevent the accuracy of the lifetime detection of the backlight from being lowered, when the device has the luminance adjusting resistance adjusting the luminance of the backlight, while changing an impression voltage to the back light. SOLUTION: This life-detecting device 10 of a backlight 12 which irradiates a liquid crystal display panel 14 with lights from the back of the panel and is provided with a luminance adjusting resistance 18 for adjusting the luminance of the back light by changing a voltage to be impressed in order to light emission, this device is provided with a luminance sensor 20 detecting the luminance of the back light 12 and a resistance sensor 22 detecting the resistance value of a luminance adjusting resistance and a control part 24, which calculates a luminance value based on the detection values obtained by these sensor 20, 22 and detects the life of the back light 12 by comparing the luminance value with the pre initial luminance value set.</p> |
