Head-mounted display with LCOS using diffractive optical element

We designed a 60degrees hybrid refractive-diffractive eyepiece for head mounted display (HMD), and applied it in micro-display of liquid crystal on silicon (LCOS) by introducing a relay system. The hybrid eyepiece design is based on a traditional Erfle eyepiece. It has a 10mm exit pupil and a 22mm eye relief, which satisfies the requirements of HMD used in computer entertainment and visual reality. Moreover, the proposed eyepiece possesses better performances with a considerable reduction in physical size and weight compared to the traditional refractive type. The relay system can solve the matching problem between micro-display device and eyepiece, and provides the space for illuminating light source. The whole optical system is suitable for display of 18mm-diagonal LCOS with a VGA resolution.