Patent ID: 7425801

Claim:
An LED driving device comprising: a power supply voltage generator; an applied voltage storage that stores therein an applied voltage value on an each-color basis corresponding to a minimum emission voltage of an LED of each of colors, red, green and blue, provided in a display device; an applied voltage former that converts a voltage generated in the power supply voltage generator into the applied voltage value stored in the applied voltage storage to apply to the LED of each of colors; a duty ratio storage which is comprised of writable memory and stores therein, independently of the LED of each of colors, a duty ratio of a PWM signal to make a fine adjustment to luminance during an emission period of the LED of each of colors; a PWM controller which forms the PWM signal based on the duty ratio stored in the duty ratio storage independently for the LED of each of colors; and a signal line connected to the duty ratio storage to input the duty ratio to the duty ratio storage.