3D Visual Communications

3.3 Autostereoscopic Display

Instead of splitting left and right view image with the aided glasses at the viewer side for a stereoscopic display, the autostereoscopic display adopts the spatial multiplexing method to direct light emitted by pixels belonging to different views to the corresponding eyes. According to how the light-directing mechanism and optical effect are adopted, in general, we can categorize the autostereoscopic display into two major approaches: occlusion-based and refraction-based.

3.3.1 Occlusion-Based Approach

The occlusion-based approach exploits the parallax effects from the human visual system by utilizing the straight line direction characteristics of light. Imagining watching a scene through a small pinhole with the left eye only or the right eye only, each eye will observe a different image owing to the viewing angle and the occlusion caused by the opaque areas around the pinhole. By carefully applying this principle, one can build a parallax barrier display with a two-layer design as shown in Figure 3.1. The back layer consists of a pixelated emissive display panel, such as LCD, which interleaves the pixels from the left image and the right image such that the odd column pixels show the image for one eye and the even column pixels for the other eye. The front layer consists of an opaque layer with narrow regularly spaced vertical slits to allow light pass only to the desired viewing eye.

Since the light emitted from the left and right pixels is directed/blocked ...