A projection-type video-image-displaying device efficiently displays an image by reducing the loss of light in the device. The device is provided with a light source radiating white light, a rod lens, a rotary color filter, a DMD, illumination optical elements, a projection lens and a control device. The rod lens collects light from the light source and emits the light. The rotary color filter selectively transmits, from the white light, light of a specific color. The DMD modulates incident light in accordance with an image signal, and the illumination optical elements form illumination light for projection onto the DMD. The projection lens projects an image formed using the DMD. The control device synchronizes the rotary color filter with the image displayed by the DMD. The DMD is disposed in a substantially conjugate relationship with the light-emitting surface on the rotary color filter.