HEAD-UP DISPLAY

A head-up display for displaying an image as a virtual image to an observer includes a projection optical system that includes a lens element and a reflecting mirror. A light beam reaching a center of a viewpoint region of the observer and corresponding to a center of the virtual image is defined as a reference light beam. The lens element is inclined with respect to the reference light beam. The lens element includes an entrance surface on which light of the image is incident, an exit surface from which light of the image emerges, a first edge portion, and a second edge portion. The second edge portion is inclined so that, when light emitted from the image travels through the entrance surface, the second edge portion, and the exit surface in this order, light emerging from the exit surface reaches below a central portion of the reflecting mirror.