A projection device comprises a light source, a color wheel which is inserted into an optical path of the light source and in which a plurality of color segments are formed along a peripheral direction of the color wheel. The color segments are configured to transmit a plurality of wavelength band components in the white light in a time division manner during a rotation of the color wheel. A light source driving unit alternating-current discharges the light source at a period shorter than a rotation period of the color wheel while reverses a polarity at a timing to switch the segment of the color wheel inserted into the optical path.