Field Reconstruction of Holograms for Interactive Free Space True Three Dimensional Display

Abstract

Holographic display can show pictures in the way that looks like the same with the real world, and is thought as the ultimate display technology. But due to the complexity of the traditional holographic technique, it can hardly be applied to commercial display systems. In this paper, the field reconstruction of holograms (or real-time reconstruction of holograms) method, which is more practical and better than traditional holographic technique in image quality, is first proposed for realizing the display of true 3D image at free space. By combining the advantages of geometrical optics and the wave optics, a true 3D display is successfully designed.And by designing an interactive image generation chip, the designed 3D display allows user to interact with the 3D image in the style that's natural to them.Keywords: Field reconstruction of holograms; Interactive; True 3D display movies. This kind of magical displaying form always makes us admire. Nowadays, the 3D display technology attracts great academic and industrial attention due to its rapid development and applications in providing more realistic, natural, and extra depth images that are lacking in the traditional 2D display[1]. To achieve natural and comfortable 3D visual perception, a considerable amount of efforts have been dedicated, and some practical designs have been proposed. Among them the 3D display technology those based on two eyes parallax are the most mature ones [2]. But these kinds of 3D displays are not real 3D displays which are easily cause visual fatigue because of the accommodation-vergence conflict [3,4] and they have some other disadvantages, i.e., the fixed range of the viewing distance, view position, and the fixed interpupillary distance value (usually 65mm). The parallax barrier technology seriously reduces the brightness of images, so it is replaced by lenticular sheet technology in most products. In the lenticular based autostereoscopic display, the role of the lenticular lens is to magnify and transfer the information of specific pixels to a designated position [5]. The depth-reversal is considered as an inherent disadvantage of the lenticular based or the parallax barrier based autostereoscopic displays. Integral imaging is a kind of true 3D technology, which is based on the principle of reversibility of light [6,7]. But due to the poor resolution and complex structure, even it has been proposed by Lippmann for around a century, it still not been accepted by the market. Volumetric 3D display is another kind of true 3D displays, which also has some inherent defects [8]. The mechanical rotating components of it limits the image's spatial and brings in some potential danger.

Application of the technical - pedagogical resource 3D holographic LED-fan display in the classroom

“…"It is difficult to construct a three-dimensional image in free space allowing view from all directions or positions. From a mathematical point-of-view, the construction of 3D image in free space is a definite boundary solution problem of passive space" (Wang, 2017).…”