摘要
对一款折衍混合投影式头盔(Head-mounted projective displays,HMPDs)物镜进行了精确的视空间评价,并给出了详细的评价步骤和评价结果。在对调制传递函数(MTF)进行评价时,充分考虑了人眼的焦距和瞳孔对评价结果的影响,给出了调节和像散所造成的分辨力损失的计算公式。评价结果显示:对于3 mm瞳孔,该系统中心视场调制传递函数在0.5 cycles/(′)达到了0.55,达到了人眼的最小分辨角(1′)。当眼睛注视投影像面中心时,轴外点最大需要0.35D的调节量,由此造成的分辨力损失最大为3.5′。由于像散造成的分辨力损失最大只有1.1′。横向色差和二级光谱最大值分别只有0.57′和0.17′,均小于人眼的最小分辨角。这些结果证明此设计满足投影式头盔物镜的使用需要。该方法适用于所有的头盔系统在视空间的性能评价。
A detailed assessment including the assessment procedure and the result in visual space of a projection lens design for head-mounted projective displays is presented. The influences of the focal length and the pupil size of the eye on the modulated transfer function （MTF） are sufficiently considered. The formulae to compute the loss in resolution due to accommodation shifts and astigmatism are given. The results show that for a 3 mm pupil size, the MTF is 0.55 at 0.5 cycles/（＇）, matching the visual acuity of the human visual system （1＇）. When the eyes gaze at the center of the projected image, the accommodation shifts of points in the full field of view are less than 0.35D. And the loss in resolution due to accommodation shifts is less than 3.5＇. The maximum loss in resolution due to astigmatism is only 1.1＇. The maximum value of the lateral color and secondary color are only 0.57＇ and 0.17＇, less than the visual acuity of the human visual system. The results demonstrate that the lens can fulfill the usability in head-mounted projective displays. That technique can be applied to all the HMDs.
出处
《光学学报》
EI
CAS
CSCD
北大核心
2006年第5期730-735,共6页
Acta Optica Sinica
基金
国家自然科学基金(60577015)资助课题
关键词
应用光学
投影式头盔系统
视空间评价
光学设计
applied optics
head-mounted projective displays
optical assessment in visual spacer optical design
