HEAD-UP DISPLAY DEVICE

A head-up display device includes: light sources; a light source driver that drives the light sources; a second control unit that illuminates the light sources via the light source driver on the basis of illumination control data; and a DMD display element that generates display light on the basis of illumination light emitted by the light sources. The illumination control data includes control modes for generating the illumination light brightness corresponding to a requested brightness. The control modes have differing brightness ranges, which partially overlap each other. The second control unit switches modes between the control modes when the requested brightness has reached a mode switching value, which is located in a non-end part of an overlapping region where one of the brightness ranges of one of the control modes and another one of the brightness ranges of another one of the control modes overlap.