To provide a video display device capable of making a boundary part on a screen inconspicuous by easy control, when displaying video on a large-size screen, by using a plurality of projection devices.

The video display device is equipped with phototransistors performing photoelectric conversion, when receiving infrared rays, and red, blue and green light-emitting diodes connected to the phototransistors on the screen 2, and bias voltage is applied to them. The phototransistor on the screen is constituted so that the wavelength of infrared light, for which the photoelectric conversion is performed may be different in every region, and outputs a current in accordance with emitted light quantity and gives it to the light-emitting diode only when receiving the infrared light radiated from the corresponding projector. The light-emitting diode emits visible light having luminance in accordance with the current amount.