LED CONTROL DEVICE, LED CONTROL SYSTEM AND LED CONTROL METHOD

摘要

To provide a technology of LED drive control, capable of controlling a lighting period of an LED satisfactorily up to a small duty ratio while enabling power consumption to be suppressed.SOLUTION: An LED control device includes: a drive circuit for PWM controlling an output of an LED row; a power supply circuit for performing step-up operation interlockingly with a signal executing PWM control and supplying a voltage to at least one LED row; an error amplifier for outputting, to the power supply circuit, a control signal controlling so that a voltage supplied to the LED row from the power supply circuit is a voltage corresponding to a reference voltage; and variable means for varying a voltage value of a reference voltage of the error amplifier on the basis of a duty of a signal executing PWM control.SELECTED DRAWING: Figure 4