| 摘要 |
In a backlight using an LED, area control is performed such that the backlight is lit only in the bright area of the screen and the backlight is not lit in the dark area. The temperature change in the light emission efficiency of the LED is large. The temperature of the lit LED is high in area control, so that when a completely gray screen is displayed after the area control, the light emission efficiency of the LED decreases in the previously illuminated area, resulting in the occurrence of uneven brightness. The present invention prevents the uneven brightness of the screen in area control, by reducing the temperature change in the light emission efficiency of the LED to 5% or less, and more preferably 3% or less, in a temperature range of 50° C. to 90° C. |
