US Patent 7946708 Display device that projects a virtual image display

A display device includes a light source that supplies light, a phase modulator that modulates the phase of the light from the light source to form an image, and an imaging optical system that focuses the image formed through the modulation performed by the phase modulator. The phase modulator produces diffracted light according to a phase modulation pattern while changing the phase of the light so as to form an intermediate image between the phase modulator and the imaging optical system, and the phase modulator also changes the position of the intermediate image.