Retinal projection display with realistic accommodation cue

Although retinal projection displays have the feature of being always in focus and no loss of image resolution, the lack of accommodation cue makes it difficult to perceive the depth correctly. In this paper, we proposed a retinal projection display system with realistic accommodation cue. The proposed system adds an optometric device to the conventional holographic optical element (HOE)-based retinal projection display. The optometric device detects the accommodation response of the human eyes to observe a real scene at different distances. According to the focused depth of the human eye, refocused images containing realistic focusing and defocusing information are generated through the light field refocusing technology. By establishing a focus depth-lookup table, the refocused images matching with the focused depth of human eye was presented to the human eye, so as to restore the retinal projection display with realistic accommodation cue. A proof-of-concept prototype based on the proposed structure was developed, and the experimental results presented retinal projection displays with realistic accommodation cue at a depth between 250 mm and 400 mm. The proposed system retains the characteristics of high resolution and free focusing while adding the accommodation cue. The developed prototype has great competitiveness in near-eye displays.