We have developed a 128-directional display having SVGA resolution. We had previously constructed 64-directional, 72-directional, and 128-directional displays in order to explore natural 3D display conditions to solve the visual fatigue problem caused by the accommodation-vergence conflict. We found that these displays enlarge the depth of field of an eye imaging system; however, their resolution was as low as ~QVGA. In the present study, we develop a 128-directional display whose resolution is increased to SVGA, thereby enabling investigation of the influence of 3D resolution on human 3D perception. The newly developed display consists of 128 small projectors having SVGA resolution. Each projector uses one LCOS device, and the field sequential technique is used to display color images. All 128 projectors are aligned in a modified 2D arrangement; i.e., all projectors are aligned two-dimensionally and their horizontal positions are made different from one another. All images are displayed in different horizontal directions with a horizontal angle pitch of 0.28°. The horizontal viewing angle is 35.7°, and screen size is 12.8 inches. The display is controlled by a PC cluster consisting of 16 PCs. In order to correct image distortion caused by the aberration of imaging systems, images displayed on the LCOS devices are pre-distorted by reference to correction tables.
We developed a new virtual reality (VR) system that enables direct interaction between a 3D image and a finger without wearing special 3D glasses and without attaching any marker or detector to the finger. Moreover, it frees the user from visual fatigue. The system consists of a 128-directional 3D display, a PC cluster, and a fingertip detection system. The 128-directional display provides a natural 3D image which does not have the accommodation-vergence conflict and has very smooth motion parallax. It differs from conventional multi-view displays in that it precisely reconstructs rays from a 3D object. It contains 128 LCD panels, and the 128 images displayed on them are projected in different horizontal directions with a horizontal angle pitch of 0.23°. The PC cluster consists of 16 PCs. Each PC generates eight video signals. The fingertip detection system employs a stereo infrared (IR) camera. The 3D position of the fingertip is estimated by triangulation. We also made three application programs. The first one enables the fingertip manipulation of a 3D image in VRML format. The second one is a 3D drawing program that allows users to draw lines in the air. The last one enables the rotation of a 3D image of a 360° directional image by the finger.