Design of a 50° Field-of-View Object for Head-Mounted Projective Displays and Investigation of Retro-Reflective Materials

A head-mounted projective display lens with a field-of-view of 50° for medical application is designed. The exit pupil diameter of the system is 8mm, while the maximum diameter of the lens is 10 mm. The total length of the designed system is 10 mm and the weight is only 5g .The maximum distortion of the system is less than 0.64% and the maximum field curvature is 0.35 D. The lens can satisfy the requirement of a 0.9 inch miniature display with a display model of SXGA. To know the imaging performance of the HMPDs different retro-reflective materials were investigated. It is shown in the experiments that the image power of the High Intensity Grade Reflective Sheeting is fairly constant for a tilted angle in a range of ±40°. Therefore it can be used as retro-reflective screen. The influence of retro-reflective material´s position on the imaging properties are also investigated.