In recent years, head-mounted display systems tend to develop into planar see-through display which is much smaller and lighter. Considering ghost images in planar display based on transparent film array with 45° inclination, a novel improved structure is proposed. By reducing inclination of films, the inclinations of different Field of View (FOV) in the waveguide increase, which means exit-pupil can be extended. In such case, beams that may cause ghost images also change their propagating paths. At the same time, dual-layer waveguide which has a filmed layer and a non-filmed layer can constrain conditions of ghost images when its size is limited. According to analysis and calculation, a design with 24° film inclination is presented, which can realize horizontal and vertical expansion. The system can also achieve 20° horizontal FOV and 114° vertical FOV.%微型化、轻型化的穿透式平板显示是近年来穿透式头盔显示的主要发展方向.本文针对传统的45°倾角半透膜阵列式平板显示的鬼像产生问题进行分析,提出了一种改进型的平板显示结构.通过减小膜层倾角,不仅使得各视场光线在波导中的倾角增加从而保证出瞳扩展,而且改变了产生鬼像光线的传播路径.同时,采用有膜层和无膜层的双层波导结构以及特定的尺寸限制,有效地约束鬼像产生的条件.根据分析计算,设计了一种膜层倾角为24°的系统结构,实现了水平和垂直方向的二维扩展,以及20°水平视场和13.4°垂直视场的显示输出.
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