Novel optical system design method for smart glasses

The design idea of the curved waveguide micro-projection optical system glasses using Fresnel microstructure was proposed.The imaging principle of the proposed optical system was theoretically analyzed, the optical design method was given, and a set of prototype was designed by using this method. The front surface radius of curved waveguide plate (that is, close eye surface) is 140.0 mm, the back surface radius is 143.5 mm, the center thickness is 1.7 mm, the material selected is PMMA(ie plexiglass), the micro-display chosen is 0.23″ silicon-based OLED display, the resolution is 640×480 (pixel), the diameter of the exit pupil is 8 mm, the eye point distance is about 18 mm, the field of view(FOV) angle is 9.6° (H)×7.2° (V), and the modulation transfer function (MTF), at the spatial resolution of 30 lp/mm, is close to 0.45 for the center field, greater than 0.2 for the whole field, which verifying the feasibility of the proposed method.