LIGHT SOURCE LIGHTING DEVICE, LIGHT SOURCE LIGHTING METHOD AND ELECTRONIC DEVICE

摘要

PROBLEM TO BE SOLVED: To improve the conversion efficiency of a light source driver.SOLUTION: A light source lighting device comprises: a DC/DC converter 2 which converts an input voltage into a first voltage; and a light source driver 3 which receives, as its input, the first voltage outputted from the DC/DC converter 2 and changes its output voltage to be applied to a light-emitting device 4 so that a predetermined amount of driving current may be flowed to the light-emitting device 4. At the start of lighting the light-emitting device 4, the DC/DC converter 2 fixes the first voltage at a predetermined voltage, whereas after lighting the light-emitting device 4, the DC/DC converter 2 adjusts the first voltage in such a manner that a difference between an input voltage Vin and an output voltage Vout of the light source driver 3 may be at a predetermined value.