VIDEO DISPLAY DEVICE
FIG6 is a diagram illustrating another example of the drive gradation table 
FIG6 shows another example of the drive gradation table. In accordance with the drive gradation table in FIG6, SF4 turns on at the time of Gradation 1, and the subframes which turn on are increased in a temporarily posterior direction as the gradation rises, and SF1 is turned on at Gradation 10. That is, SF1 to SF3 are not turned on up to Gradation 9. At this time, the light source controller 14 only needs to make control so that the visible light source 1 is not turned on during an approximate period equivalent to SF1 to SF3.
diagram
7
projection lens
5
PBS
12
subframe data generator
11
signal processor
1
visible light source
9
Gradation
4
illumination optical system
2
infrared light source
6
liquid crystal display element
10
signal synthesizer
3
dichroic mirror
['1. A video display device (100) comprising: a display element (6); a visible light source (1) configured to irradiate visible illumination light; an infrared light source (2) configured to irradiate infrared illumination light; a subframe data generator (12) configured to generate subframe data based on a mixed video signal in which a frame of a video signal for a visible light image and a frame of a video signal for an infrared light image are alternately repeated, the subframe data indicating on and off of an applied voltage to the display element (6) in the frames; a pixel circuit (13) configured to drive the display element (6) based on the subframe data generated by the subframe data generator (12); and a light source controller (14) configured to control on and off of the visible light source (1), wherein, when gradation of the mixed video signal is equal to or less than a predetermined gradation, the subframe data generator (12) generates the subframe data so that an applied voltage to the display element (6) is turned off during a first predetermined period from a start of the frame of the video signal for a visible light image or the video signal for an infrared light image, and wherein the light source controller (14) turns on the visible light source (1) after a lapse of a second predetermined period from a start of the frame of the video signal for a visible light image, and turns off the visible light source (1) at a  timing when the frame of the video signal for a visible light image is ended.']