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

摘要

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.