Abstract
Several market studies have shown that naked eye 3D display could be especially useful for advertisement in open space, because potential customers come and go randomly, which makes it a difficult occasion for glass-type 3D demonstration. An optical architecture to solve the three main issues: color separation, dark zone and Moiré effect in autostereoscopic 3D LED display panel is proposed in this paper. In order to keep the luminance in outdoors, lenticular array is chosen to be the approach to image 3D images. Color separation issue is caused by horizontal arrangement of RGB LED image to the viewing plane, and gaps between RGB LED chips could induce dark zones. First of all, an optical called converging optics is introduced. It converge the light path of RGB sub-pixels and mix three colors in color mixing pixels. After color mixing pixels, there is a 3D lenticular array to image them to viewing plane to make 3D image. The color converging optics not only eliminates the artifact of color separation associated with most LED displays, but also reduces the dark zone in naked-eye 3D display application. Since the fabrication of the converging optics which both surfaces of the component feature periodic yet complicated and piecewise free form profile is not trivial, an alternative design called double lenticular is proposed for the ease of realization. Double lenticular is composed of two lenticular arrays, both with spherical surface. By using double lenticular, the chromatic artifact and dark zone on the viewing plane have been significantly reduced. If RGB LED arranges in vertical direction, color separation in horizontal would not be significant. Nevertheless, dark zones may still exist in viewing plane. Also using double lenticular can eliminate dark zones, but the Moiré effect is observed according to the interference between double lenticular and 3D lenticular. For reducing this phenomenon, the third method which is named slanted lenticular is described. This final version of micro optics can eliminate dark zones without Moiré effect simultaneously.