Moiré Reduction Technique for Near-Virtual-Image-Mode Light Field Displays via Aperture Array Modification

Flat-panel-type light field displays can generate three-dimensional images viewable without glasses; however, they often suffer from a narrow viewing zone, low light efficiency, low resolution, and moiré artifacts. Previously, flat-panel-type light field displays with a near-virtual-image mode were proposed, comprising a lens array and an aperture array; these displays offered an enhanced viewing zone, increased light efficiency, and improved resolution. In this study, a moiré reduction technique is proposed for near-virtual-image-mode light field displays. In this configuration, moiré artifacts arise from the periodic deformation of virtual subpixel images seen through the lens array, caused by the nonrectangular subpixel structures for the R, G, and B colors of the display panel. To suppress the differences in subpixel shapes, the aperture shapes in the aperture array were modified from straight to zigzag shapes. Zigzag-shaped slits were designed, and their effectiveness in reducing moiré artifacts was evaluated using a diffraction-based moiré analysis technique. Experimental results demonstrated a lower moiré contrast with the designed zigzag slit than with the conventional straight slit, confirming the effectiveness of the proposed technique.