Establishment Of Multi-Color Volumetric Display System And Studies On Its Properties

Volumetric three-dimensional (3D) display technique is a feasible way to realize true 3D display which displays images in an actual 3D space, with most characteristics similar to real-world objects. Nowadays with the mature development of two dimensional (2D) display and relative industry, more and more people focus on developing true 3D display technique. Some 3D display prototype systems have been built in the world recent years. However, due to many technical difficulties, most of the systems have poor performance: small display space, low resolution, only monochromatic and static display, etc. Therefore, we tried to develop a high resolution multi-color volumetric display system based on 2D rotating LED panel. It is a system with excellent performance, which provides large display space, multi-color, high resolution and real-time dynamic 3D display. Now it has been successfully completed.In this paper, implementation of software and hardware of the system was presented, including the generation and simulation of the voxel data, high-speed wireless transmission of the massive data, realization of dynamic display for large 3D scene, design of the high-speed drive circuit, realization of the small pitch, large size and high density multi-color LED panel, optimization of the mechanical system, etc. The display space of the system is the largest one in 3D display field in the world up to now.Proper voxelization algorithm namely scan mapping method for line voxelization was presented, which scanned LED array in both row and column directions according to the voxel' s shape, size and distribution. Both simulation results and numerical analysis show that the algorithm is effective. Generation and simulation of voxel data with multi-color for this system was built, which generated color information for voxels and simulated them on PC screen. Different simulation results for the same original model under different LED panel resolution or 2D slice number per rotation were given and compared, which could specify proper hardware parameters.Evaluation of texture distortion due to voxels' position deviations caused in voxelization was proposed, based on human visual system and texture detail distribution. The merit function of texture distortion was set-up, considering voxel' s position deviation, distribution of details in textures and voxel's relative gray scale. 3D Models with textures having different gray scale distribution were built and texture distortion of them was evaluated by the merit function. Numerical analysis and simulating results were also given. The voxelization algorithm was improved for the type of textures in which distortion was serious.Up to now many studies have been done on the establishment of 3D display systems. However, none of them concerns about the testing of optical performance of 3D display systems, evaluation of 3D images and the problems of 3D display. Hence this paper presented studies on the brightness uniformity and chroma uniformity of 3D display space, both accurate testing and numerical analysis were given. The dead zone of 3D images displayed by LED volumetric display system was discussed and investigated in detail. Moreover, experiments were done to show that LED volumetric display was capable of occlusion utilizing lenticular or parallax-barrier.