HEAD-UP DISPLAY, HEAD-UP DISPLAY SYSTEM, AND MOVABLE BODY

A head-up display includes a display panel, a reflective optical element, a controller, and an obtainer. The display panel displays a first image. The reflective optical element reflects image light from the first image displayed by the display panel. The controller controls a position at which the first image is displayed on the display panel. The obtainer obtains, as positional information, a position of an eye of a user. The controller changes the position at which the first image is displayed on the display panel in accordance with the positional information.