3D Imaging System for Tele-Manipulation

Abstract

In accordance with the advancement of flat panel display technologies, recent researches of 3D display technologies are mostly focused on thin 3D displays using parallax barriers, lenticular lenses, or fry-eye lenses. Though some products based on these technologies have already been commercialized, they have not acquired many users. One of the main reasons why these 3D displays have not attained commercial successes is that most of these displays are developed for general purposes, not for a specialized purpose. In general, realization of 3D display has to sacrifice resolution. Also 3D displays give the viewer more eyestrains than 2D displays. In addition to these factors it should be noted that most 3D information can be obtained from 2D display with the intelligence of the viewer. Therefore 3D displays cannot be an attractive option unless they can offer substantial merits besides the impact at first impression. Then where 3D displays become necessary and essential? To answer this question, let us consider how we perceive 3D information from 2D displays. There are several factors which can help depth perception from a simple 2D image. One of the most important factors is motion. Near objects tend to move faster than far objects in the 2D image. When the motion comes from the camera work, this relation always holds as long as the objects themselves are static. In this case it can be said that motion pictures on 2D display are presenting 3D information composed of x axis, y axis, and time axis. In other word, 2D displays cannot present 4D space composed of x axis, y axis, z axis, and time axis, which 3D displays showing motion pictures can present. Then when 4D perception is necessary? One answer is real-time operation of 3D space. In real-time tasks such as tele-manipulation of robots or remote car driving, the operators or the drivers are required to grasp 3D location of the objects on the real-time basis. They cannot spare time to wait and see the change of image to perceive depth. Real-time interaction systems where the viewer needs to perceive 3D space instantly include interactive visualization, 3D drawing, surgery simulations, etc. besides robot tele-operation and car driving. Since interactive systems can be used for various kinds of tasks, desired design of the system varies depending on the features of interaction. Therefore ready-made 3D displays cannot meet up with the requirement of the users. To increase the number of 3D display users for specialized purposes, it is important to present 3D displays designed for each use with low cost because we cannot expect cost reduction by mass production. 34