Image display device with exit pupil moving for tracking viewer's pupil

Abstract

An image display device for optically displaying an image is disclosed. This device includes: a light source; an imaging-light generator converting light emitted from the light source, into imaging light representative of the image to be displayed to a viewer, to thereby generate the imaging light; and an exit-pupil controlling unit configured to control a position of an exit pupil of the image display device. The exit-pupil controlling unit includes: an electrically controllable element configured to diffract the imaging light incoming from the imaging-light generator, at an electrically-variable diffraction angle; and a controller configured to electrically control the diffraction angle of diffracted light emitted from the electrically controllable element, to thereby control the position of the exit pupil.

Dependencies are inferred from the claim text.