A display device includes a solid-state light source driven by a PWM signal, a light modulation device that modulates light emitted by the solid-state light source in response to an image signal, and a signal output unit that determines a duty ratio and a current value of the PWM signal in response to brightness of an image represented by the image signal. The signal output unit outputs a PWM signal having a predetermined first current value to the solid-state light source if the duty ratio is equal to or more than a predetermined first threshold value and outputs a PWM signal having a current value less than the first current value to the solid-state light source if the duty ratio is less than the first threshold value.