Patent ID: 7049752

Claim:
A control device of LEDs, comprising: driving means for driving LEDs; and pulse output means for varying a cycle and a corresponding duty ratio of a pulse signal outputted to the driving means to control the driving means, wherein the pulse output means includes lighting-up means that gradually increases the cycle and the corresponding duty ratio of the pulse signal during a lighting-up period of the LEDs beginning at a start of a lighting-up of the LEDs. wherein the lighting-up period includes a plurality of cycles, wherein the cycles serially take place and wherein each of the cycles is corresponded to by a duty ratio, wherein the lighting-up means includes: given cycle set means for setting a cycle of the pulse signal; given duty ratio set means for setting a duty ratio of the pulse signal; and given update means, wherein, during the lighting-up period of the LEDs since the lighting-up of the LEDs starts, the given update means outputs, within a cycle set by the given cycle set means, a pulse signal having a time width relative to a corresponding duty ratio set by the given duty ratio set means, and wherein, when a cycle elapses, the given update means instructs the given cycle set means to set a cycle taking place subsequently to the elapsed cycle by increasing the elapsed cycle and instructs the given duty ratio set means to set a duty ratio corresponding to the cycle taking place subsequently to the elapsed cycle by increasing the duty ratio corresponding to the elapsed cycle.