Optical system of augmented reality glasses with saw tooth-type partial reflector array

Abstract

The present disclosure relates to an optical system of augmented reality glasses with a saw tooth-type partial reflector array which projects image light and external image light to user's eyes with a high transmittance. To this end, the optical system of augmented reality glasses includes a display devicewhich generates image light; a polarization elementwhich is opposite to be parallel to the display deviceand determines a polarized component of S-pol or P-pol; a lenswhich is provided at one side of the polarization elementand magnifies and focuses the image light passing through the polarization elementto form a focal surface in the waveguide; and a lenswhich is provided at one side of the polarization elementand focuses image light passing through the polarization element; and a waveguidewhich allows the image light to be incident from the lensand expand an exit pupil of the incident image light to a horizontal direction to be emitted toward the user, in which the waveguideincludes: a first surfaceand a second surfacewhich allow the image light to be incident to be totally reflected and are parallel to each other; an incident surfacewhich forms a predetermined incident angle θi with the first surface; a partial reflector arraywhich is provided on the first surfaceand the second surfaceand has a saw tooth structure formed by alternately providing the transmissive surfacethrough which the totally reflected image light is transmitted and the reflective surfacethrough which the transmitted image light is reflected; and a polarization coating layerwhich is formed on the saw tooth structure and has an angular bias that shows different reflectance according to the incident angle at which the light is incident on the transmissive surfaceor the reflective surface