The invention relates to a small and light wide-field free-form surface
prism HMD optical
system, which belongs to the field of optical
system and device design and is applied to the
virtual reality and
augmented reality field. The invention comprises a free-form surface
prism with three optical surfaces, and a micro-
image display; the free-form surface
prism is made of plastic glass materials with the
refractive index greater than 1; the three free-form optical surfaces are concave surfaces, which meet one of the three surface-type equations, and the location relationship of each surface meets three condition equations; the incident angle formed between the widest-field upper edge rays emitted by an LCD and the second free-form surface meets the total reflection conditions; and an image
source element is an LCD of 0.61 or 0.59 inches. The small and light wide-field free-form surface prism HMD optical
system is light and compact and has the advantages of good aberration correction and high
light energy utilization rate; the optical system enables the observer to see clear images in a
wide field of view, and the displayed images do not have apparent brightness attenuation and can not easily cause visual fatigue to the observer.