Patent ID: 8633892

Claim:
A projection display device comprising: a light source unit configured to emit lights, the light source unit including first to third light sources; a light combining unit configured to divide a light from the lights emitted by the light source unit and to selectively combine the lights from the light source unit; an image projection unit configured to project an image using the combined light from the light combining unit; and a virtual input unit configured to project an input unit image using the light divided from the light combining unit, wherein the light combining unit includes: a first dichroic mirror arranged at a position where a first light from the first light source and a second light from the second light source cross each other, the first dichroic mirror configured to transmit the first light while reflecting the second light, but also to reflect a portion of the first light or to transmit a portion of the second light such that the portion of the first or second light is sent toward the virtual input unit; and a second dichroic mirror arranged at a position where the first light from the first light source and a third light from the third light source cross each other, the second dichroic mirror configured to transmit the first light and the second light while reflecting the third light.