A projection device for providing an image light includes a light source module configured to provide an illumination light, a dichroic film configured to allow a first portion of the illumination light to transmit therethrough to form a light in a first wavelength range and to reflect a second portion of the illumination light into a light in a second wavelength range different from the first wavelength range, a first digital micromirror device (DMD) configured to reflect the light in the first wavelength range from the dichroic film into a first light, and a second DMD configured to reflect the light in the second wavelength range from the dichroic film into a second light, wherein the first light and the second light together form the image light.