A projector includes a light source unit that supplies light, and a spatial light modulator that modulates light supplied from the light source unit according to an image signal. The spatial light modulator is driven by an applied voltage whose polarity is reversed according to a polarity-reversing frequency which is specific to the spatial light modulator. The light source unit supplies light which is modulated according to pulse width modulation for which fundamental frequency is set based on the polarity-reversing frequency.