| With the rise of the technical level of display, the functions of novel displays we are seeking become more and more diverse. Human-computer interaction (HCI), three-dimensional (3D) display and laser display are the important research fields in modern optical display. However, there are some problems for the technology itself or its application in the display, for example, the theory of the3D display based on lens array is not sound, the problem that traditional imaging device can’t be effectively integrated with display system makes it difficult to realize HCI, and so on. Making realization of the HCI in display system as the structural thread, a variety of bi-directional imaging and display methods, where the function of imaging and display do not affect each other, are proposed and studied. Among them, LCD screen-lens array far field imaging system with high integration can achieve HCI based on2D information, such as facial expressions, eyeball action, lips and gesture. The3D bi-directional imaging and display system using lens arrays makes observer personal on the scene, and3D imaging extracts complex information such as body movement to effectively achieve the advanced HCI-virtual reality(VR) effect. Close to the demand and application of market, this paper presents two kinds of new3D display solutions, especially single projection3D display system using laser source.Laser scattering can be not only applied to eliminate laser speckle, but also used to determine parameters of object by the measurement of scattered light. This inverse scattering technique inherits many advantages for traditional optical diagnosis technology. For the particle size distribution and concentration are very important parameters in design of rear projection screen and stutdy of kerosene-fuel supersonic scramjet combustor, particle-sizing from scattered light pattern has been studied in this paper.The main research works are as follows:1. The basic imaging theory of lens array is described in detail by light field. For the application in HCI, various digital techniques to recover3D information form array image are introduced and summarized, including their basic principle and numerical algorithm.2. The model of3D display by lensarray is established with consideration of the parameters and focus characteristics of human eye. The evaluation of the performance of3D display system is given from view. We study the optimum design method for display with high quality, where the conjugate position of display plane and fill-factor of lensarray are variable. The results show that:the response range of eye for each element lens is proportional to the filling factor of lensarray and pupil aperture; Large value of F-number can extend view field, while introduced more aberration which may decrease the quality of display, F-number>2must be met; small display pixel and fill factor of lensarray makes the conjugate position of display plane away from the lensarray, the maximum depth of3D reconstructed image become large.3. In order to resolve problem of eye-gazing, imaging module consisted of lensarray and detector array is integrated with LCD to perform far field imaging without affecting display, i.e. LCD-lensarray bi-directional imaging and display method. The model of Far-field imaging by lensarray is built, based on which effect of system parameters on array imaging is researched. The results show that:the value of F-number should be larger than4.5to achieve image with diffraction limit for on-axis detector;2%criterion can be used to determine the number of the sampling points contributing to the detector. The ratio of focal length and detector pixel size should be at reasonable value in order to maintain high light collection and far working distance. Two experiments are carried out, where limiting field and separating light are used to prevent signal disturbance respectively. The image restoration algorithm is applied to improve lateral resolution and working distance. It is proved that the truncation error by2%criterion has very little influence on inversion result.4. Various bidirectional3D imaging and display solution are proposed in order to realize virtual reality HCI. For the Polymer Dispersed Liquid Crystal (PDLC)-lensarray3D imaging and display projection type system, imaging characteristics of the lensarray associated with camera are analyzed. Combined the3D display analysis results, the overall system design is presented. This paper also studies the highly integrated flat panel display-lensarray bidirectional3D imaging and display scheme. Two new3D display method wearing glasses type are also proposed, including polarization film-LED display big screen3D display and single projection 3D display based on the liquid crystal (LC) polarization rotation. For the latter, different design schemes are given in view of the different liquid crystal response, projection type. We also build a single chip rear projection display system with the laser source, good display quality is achieved.5. Light scattering theory and the principle of inverse scattering measurements are described in detail. In order to retrieve particle size, we study the traditional Chin-Shifrin integral transform inversion algorithm, including work mechanism, existing problems and inversion performance. The results show that the diffraction approximation error can cause peak position of the inversion distribution shift, and the influence of approximation error can be ignored when approximation error ε<3%for the particle size parameters x <100and ε<10%for x>100. This paper proposes a novel iterative algorithm based on the maximum likelihood estimation-EM iterative inversion method, and the performances in the inverse problem of particle sizing are numerical calculated for different distribution types, noise level, etc. The results show that:when angle of the measurement is large enough, EM inversion algorithm can produce more accurate size distribution. Experiment measuring device using linear CCD as detector has been established, and the experimental results are analyzed.Highlights of the dissertation are as follows:1. It is first time to propose LCD-lensarray bidirectional imaging and display solution to eye-gazing problem. We establish the physical model of lens array far field imaging and study effect of main system parameters on the array imaging. Image restoration algorithms are used to improve the system and the working distance of the resolution of the system.2. It is first time to proposed bidirectional3D imaging and display solutions to realize the virtual reality HCI. This paper establishes the model of3D display by lensarray with consideration of all human eye parameters and focus features of human eye. The condition for3D display with high quality from view point is analyzed, such as no gap, continuous pattern, wide field and low aberration. Especially, the influence of the lens aperture fill factor is studied. We present two bidirectional3D imaging and display solutions PDLC-Lensarray projection system and highly integrated flat panel display-lensarray, and specific implementations are described. 3. This paper proposes and studies two wearing polarizer glass3D display techniques:polarizer film-LED display panel scheme and single chip projection3D display based on the LC polarization rotation, and a single chip rear projection display system with the laser resource is built, which effectively combines three topics of modern display technology:HCI,3D display and laser display.4. We study the influence of the diffraction approximation error on the result of Chin-Shifrin inversion algorithm, and access to the smallest retrievable range of particle size. At the same time, a novel type solution of inverse problem-EM iterative algorithm are derived, and applied to the inverse scattering particle size inversion, the experiments show that the algorithm has high convergence speed, low noise sensitivity. |
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