HEAD-UP DISPLAY

Head-up display includes: display element for displaying an image, and a projection optical system for projecting the image, which is displayed on display element, onto viewing region of viewer. The projection optical system includes combiner that is disposed at a position in an optical path from display element to viewing region of viewer. Combiner has a surface at which light incident from display element enters; the surface has a curved surface shape. Combiner has an effective region corresponding to viewing region of viewer. In the effective region, combiner has a horizontal cross-sectional shape that changes in thickness along from the center toward an end.