HEAD-UP DISPLAY DEVICE

A head-up display device includes an image display device that outputs display light of an image; a mirror having a reflecting surface that reflects the display light toward a reflecting portion, and an input shaft; a motor that has an output shaft located on an extended line of the input shaft, and rotates the output shaft; a transmission member that has a cylindrical fitting portion to which the input shaft is press-fitted and a coupling portion coupled with the output shaft and transmitting output torque of the motor from the output shaft to the input shaft; a holding member that holds the motor; and a first spring that is interposed between the holding member and the transmission member, and imparts, to the transmission member, a biasing force oriented to bring the mirror close to the output shaft.