VIDEO DISPLAY DEVICE

摘要

Disclosed is a video display device capable of degrading the image quality of video that is secretly videotaped so that the content of the secretly videotaped images cannot be used by emitting light used for other than video display from a video display unit such as a screen together with images to be displayed. Specifically disclosed is a video display system (1) which comprises a projector (202) that generates images to be displayed on the basis of a digital video signal and a screen (203) on which the images generated by the projector (202) are projected and displayed. An infrared emitting unit (204) that emits infrared light (light used for other than video display) from a video display surface while the video is displayed on the screen (203) is disposed behind the screen (203). The amount of infrared light changes in terms of time, and varies in a period of time less than or equal to a time constant of automatic iris control of a content recording device (130).