Retinal projection type super multi-view 3D head-mounted display with the variable function shutter using a DMD

We have previously proposed the retinal projection type super multi-view 3D-HMD which provides the viewer with 3D images by inducing the stimulus of the accommodation of the viewer's eye using the blurring of the multiple projected retinal image. However, in the previous HMD using a mechanical shutter, since we could not flexibly design the function of the shutter, we could not project the ideal multiple retinal image. To overcome this problem, we propose the improved 3D-HMD with the variable function shutter using a DMD as an optical shutter. In the proposed 3D-HMD, multiple parallax images are displayed by time division, and these images are converged on respective points by the holographic lens. However, the parallax image converges not only on the correct convergent point but also on unnecessary convergent points due to using the multiple exposure holographic lens. Therefore, to pass only one convergent light corresponding to the correct parallax image, we used the DMD shutter synchronized to the display device. To verify the effectiveness of using a DMD as a shutter, we made the prototype 3D-HMD and confirmed that the blur of the image by the prototype 3D-HMD can induce the accommodation. Since the high-speed optical shutter using a DMD realizes the function as a shutter by changing the pinhole image on the DMD, we can flexibly design the number and the alignment of convergent points in the proposed 3D-HMD. Therefore, in the proposed 3D-HMD, we can project the ideal multiple projection retinal image by using the DMD shutter.