Patent ID: 8294387
Filing Date: 2012-10-23
Classification: H05B

Abstract:
1. A backlight device that emits illumination light toward the exterior, comprising: a white light-emitting diode that emits white light; and a lighting control section that is capable of controlling lighting drive of the light-emitting diode by using PWM dimming, the lighting control section modifies ON time of a duty ratio by the PWM dimming and a value of supply current to be supplied to the light-emitting diode, and thereby to adjust a color tone of the illumination light, wherein the lighting control section comprises a drive instructing section that has a timer section that modifies the ON time of the duty ratio and the value of supply current in accordance with the lighting time of the light-emitting diode, where a value of effective current to be supplied to the light-emitting diode is kept constant, at the time of adjusting the color tone of the illumination light to a predetermined color tone.