VEHICULAR DISPLAY DEVICE

A vehicular display device includes a display that emits, as display light, a display image projected onto a windshield, a transparent cover that blocks an opening of a housing and transmits at least a part of the display light emitted from the display, a plurality of reflecting mirrors, and a quarter wave plate. Using a vibration direction of the display light from the display as a reference vibration direction, the quarter wave plate converts the display light transmitted from the transparent cover toward the reflecting mirror into circularly polarized light vibrating in a direction tilted by 45 degree from the reference vibration direction and converts the circularly polarized light transmitted toward the reflecting mirror from the reflecting mirror into display light vibrating in a direction orthogonal to the reference vibration direction.