Viewing zone control of super multi-view display with directional backlight

A super multi-view display provides three-dimensional images by emitting a lot of rays of different colors depending on the direction from each point on the display. It provides smooth motion parallax without special glasses, and it is expected that the observer is free from the visual fatigue caused by the accommodation-vergence conflict. However, a huge number of pixels are required on a display device because high-density rays are required for good quality images and each ray needs corresponding pixel. We proposed a new method to reduce the required number of pixels by limiting rays emitted to only around observer's pupils. The display is based on the lenticular method. As stated above, the rays should be shot out to only around observer's pupils. Therefore, the lenticular lens of which viewing zone angle is narrowed is used. But, due to the characteristics of the lenticular lens, the same image is seen repeatedly from different positions out of the viewing zone. It is called side lobe. Because of the side lobes, the rays for one eye enter the other eye. To suppress these side lobes, we proposed the lenticular lens is illuminated by the directional light. The direction of the directional light has to be changed to follow the observer's eye. We implemented optical designs based on the technique as mentioned above, and we produced a prototype display. We experimented with consideration of change of viewing angle and viewing distance. We confirmed usefulness of the proposed display by these experiment result.