HEAD-UP DISPLAY, HEAD-UP DISPLAY SYSTEM, MOBILE OBJECT, AND DESIGN METHOD FOR HEAD-UP DISPLAY

A head-up display includes a display panel, a parallax barrier, an optical system including a reflector and an optical member, and a controller. The optical system projects a virtual image of an image displayed by the display panel onto a virtual image plane which is positioned at a distance of 3.5 m to 7.5 m from eyes of a user. The controller controls the display panel such that a first image and a second image which have a parallax with each other are projected as a three-dimensional image in a field of view of the user, and a convergence angle at which the user views a point on the three-dimensional image is equal to or less than a maximum convergence angle and is equal to or greater than a minimum convergence angle, the maximum convergence angle being greater by 0.43 degrees than a convergence angle for viewing a point on the virtual image plane, and the minimum convergence angle being less by 0.43 degrees than the convergence angle for viewing a point on the virtual image plane.