狭缝光栅、柱面透镜光栅及其新构型在三维显示中的应用

介绍了三维显示技术的研究现状,综述了狭缝光栅和柱面透镜光栅在自由立体显示技术中的重要应用。回顾了各种光栅式自由立体显示系统的结构和原理;提出了如何根据狭缝光栅和柱面透镜光栅的特殊光学性质,在传统的立体显示系统中添加各种光栅形成灵活组合结构来提高立体显示效果,强调了它们在减小串扰、增大视场角、避免摩尔条纹以及提供更全面的三维信息等方面的作用。最后指出基于两种光栅的叠加构成面积大、参数均匀、价格低廉的新型透镜可实现全视差立体显示,对探索自由立体显示技术的研究很有意义。     

立体显示用柱面透镜光栅的设计

分析了柱面透镜光栅的单柱面透镜的光传输特性,进而推导出柱面透镜光栅的曲率半径、节距和厚度等重要参量的计算公式.根据这些理论公式,为15英寸柱面透镜光栅自由立体显示器设计了柱面透镜光栅的参量,通过应用光学软件ASAP模拟该立体显示器的立体视区分布,得出该立体显示器能显示良好立体图像,从而验证了理论的正确性.     

基于TracePro的狭缝光栅自由立体LED显示器件的串扰仿真

利用TracePro仿真软件对狭缝光栅自由立体LED显示器件的串扰进行仿真。首先,通过对狭缝光栅的设计原理分析,并基于LED模块的发光像素面积2 mm×2 mm,黑矩阵的面积1 mm×1 mm,设定最佳观看距离为5 m的两视点狭缝光栅自由立体LED显示器件,计算出光栅的狭缝宽度和挡光宽度都为2.87 mm。其次,利用这些参数,通过TracePro软件建立狭缝光栅自由立体LED显示器件的仿真模型,通过仿真运算得到左、右视频的光照度分布图,并通过归一化发现它们的光照度均匀性较差,观看时会导致"眩晕"现象。最后,借助自由立体显示器件串扰的测量方法,根据仿真左、右视频照度分布图的交叉曲线,定性分析了仿真结果,并结合Orign 9.1软件定量对仿真的串扰值进行计算,得出其串扰值为42.4%。这为进一步优化狭缝光栅自由立体LED显示器件的设计和性能提供了理论依据和技术支持。     

狭缝光栅自由立体显示器立体可视区域的研究

提出了反映观察区域某一点是否是合适的立体观察点立体图像质量因子的概念.根据狭缝光栅自由立体显示器的结构和工作原理并应用几何光学知识,分析得出了立体图像质量因子的计算公式,并给出了立体显示器的立体图像质量因子的计算结果.通过定义立体图像质量因子的阈值,得到狭缝光栅自由立体显示器的立体可视区域.     

自由立体显示器倾斜锯齿交错狭缝光栅的设计(英文)

针对光栅型自由立体显示方案易存在串扰和莫尔条纹的问题,提出一种莫尔条纹和可视区域均在可接受范围内的倾斜锯齿交错光栅设计方法,该方法在斜光栅结构基础上以一个像素高度的一半为单位对光栅进行分段,将相邻两段狭缝用对称三角形狭缝代替.该结构与斜光栅相比,减少了通过同一狭缝看到相邻子像素而产生的相互串扰,即减小了斜光栅存在的视点间的串扰,扩大了可视区域范围.仿真及实测结果表明倾斜锯齿交错光栅比斜光栅可视区域增加了25%,而莫尔条纹亮度只减少4.5%,具有一定的实用价值.     

自由立体显示器中锯齿状交错狭缝光栅的设计

光栅式自由立体显示由于易存在莫尔条纹和串扰的问题而影响其显示效果.利用斜光栅可减轻莫尔条纹但增加了视点间的串扰.本文提出一种减轻莫尔条纹的光栅设计方法,同时对可视区域影响较小.设计中对光栅进行分段,并将相邻两段狭缝错开一定距离.该方法能减小通过同一狭缝看到两相邻子像素之间的黑条的比例,获得较宽且较淡的莫尔条纹,从而减轻了视觉干扰.仿真结果表明该光栅相比传统垂直光栅,莫尔条纹亮度下降了108.1%,而可视区域仅减小32.8%,具有较高的实用价值.     

自由立体显示器中锯齿状交错狭缝光栅的设计

光栅式自由立体显示由于易存在莫尔条纹和串扰的问题而影响其显示效果.利用斜光栅可减轻莫尔条纹但增加了视点间的串扰.本文提出一种减轻莫尔条纹的光栅设计方法,同时对可视区域影响较小.设计中对光栅进行分段,并将相邻两段狭缝错开一定距离.该方法能减小通过同一狭缝看到两相邻子像素之间的黑条的比例,获得较宽且较淡的莫尔条纹,从而减轻了视觉干扰.仿真结果表明该光栅相比传统垂直光栅,莫尔条纹亮度下降了108.1％,而可视区域仅减小32.8％,具有较高的实用价值.     

凹面全息光栅单色仪设计

提出了单色仪在光纤传感系统中的应用,通过分析Ⅳ型凹面全息光栅的光程函数、像差校正原理和像差校正效果,以光栅为分光元件,设计了一种小型凹面光栅单色仪。单色仪使用自聚焦透镜作为入射狭缝和准直元件,PIN光电二极管作为接收元件,使用步进电机带动凹面光栅旋转扫描光谱。LabVIEW程序控制数据采集卡的数字输出,并显示采集到的光谱。单色仪结构简单、价格低廉,通过实验实现了对单色光的检测。     

导波弧光栅的曲率分布及实验设计

本文由柱面透镜会聚光的波前干涉场强度分布推导了弧光栅条纹的周期方程和曲率方程,为设计和制备各种周期和曲率的导波弧光栅器件提供了依据。     

导波弧光栅的曲率分布及实验设计

本文由柱面透镜会聚光的波前干涉场强度分布推导了弧光栅条纹的周期方程和曲率方程，为设计和制备各种周期和曲率的导波弧光栅器件提供了依据．     

平面三维显示技术的研究现状

平面三维显示技术是近年来最新出现的虚拟现实显示技术,其最大的特点是观察者无需使用任何辅助附加设备,直接用肉眼就可看到屏幕上显示的三维图像。为推进三维显示技术的发展,进一步研究了视差立体成像原理,并据此介绍几种平面三维显示方法及其工作原理,包括障栅立体显示、微柱透镜阵列立体显示、偏振片立体显示和基于微柱透镜立体显示原理的多视点系统,阐述并分析了系统的优缺点。以日本三洋公司的四视角立体显示装置、南京大学的多视点三维显示系统和NEC液晶科技的HDDP三维显示系统为例,描述了国内外该项技术近期的研究现状,分析了存在的技术难点,展望了该应用领域的发展前景。     

One-dimensional integral imaging based on parallax barrier

One-dimensional integral imaging (1DII) which only has horizontal disparity is a practical solution of high resolution in the vertical direction, low-cost, easy-viewable three-dimensional (3D) display. A 1DII based on a parallax barrier is proposed in this paper. The 1DII consists of a parallax barrier and a display panel. The operation principle and parameter calculation of the 1DII are described in detail. Two prototypes of the proposed 1DII and conventional 1DII based on a lenticular lens array are developed. The proposed 1DII improves the quality of the 3D image and provides larger viewing angle than that based on a lenticular lens array, and it is simpler and has lower cost than that based on a lenticular lens array.     

Micro-projection dynamic backlight for multi-view 3D display

A micro-projection dynamic backlight for multi-view three-dimensional(3 D) display is proposed. The proposed backlight includes a light emitting diodes(LEDs) array, a lenticular lens array, and a scattering film. The LED array, the lenticular lens,and the scattering film construct a micro-projection structure. In this structure, the LEDs in the array are divided into several groups. The light from each LED group can be projected to the scattering film by the lenticular lens and forms a series of bright stripes. The different LED groups have different horizontal positions, so these bright stripes corresponding to different LED groups also have different horizontal positions. Therefore, they can be used as a dynamic backlight.Because the distance between the LEDs array and the lenticular lens is much larger than the distance between the lenticular lens and the scattering films, the imaging progress will make the width of the bright stripes much smaller than that of the LEDs, and the pitch of the stripes is also decreased. According to the 3 D display theory, the bright stripes with small width and pitch help to increase the number of views. Therefore, the proposed micro-projection dynamic backlight is very suitable for multi-view 3 D display. An experimental prototype was developed, and the experimental results show that the micro-projection dynamic backlight can correctly complete the directional projection of the parallax images to form a 3 D display.     

Stereoscopic Full-Color Light Emitting Diode Display Using Parallax Barrier for Different Interpupillary Distances

The viewing areas of stereoscopic full-color light emitting diode (LED) displays using parallax barriers are investigated for viewing by observers with different interpupillary distances. We have developed stereoscopic full-color LED displays using three types of parallax barriers for different interpupillary distances. Experiments on distance perception of stereoscopic targets have been conducted with the stereoscopic LED displays using parallax barriers, as well as a stereoscopic LED display using polarizing eyewear. It was shown that enlargement of the viewing area allows several viewers with different interpupillary distances to view a stereoscopic image. It is suggested that parallax barriers designed for narrower interpupillary distances than the viewer’s own provide a viewer with stereoscopic perception.     

Autostereoscopic 3D projection display based on two lenticular sheets

We propose an autostereoscopic three-dimensional (3D) projection display. The display consists of four projectors, a projection screen, and two lenticular sheets. The operation principle and calculation equations are described in detail and the parallax images are corrected by means of homography. A 50-inch autostereoscopic 3D projection display prototype is developed. The normalized luminance distributions of viewing zones from the simulation and the measurement are given. Results agree well with the designed values. The proposed prototype presents full-resolution 3D images similar to the conventional prototype based on two parallax barriers. Moreover, the proposed prototype shows considerably higher brightness and efficiency of light utilization.     

Autostereoscopic display based on multi-layer lenticular lens

An autostereoscopic display based on a multi-layer lenticular lens was proposed. The autostereoscopic display is composed of a flat panel display and a multi-layer lenticular lens sheet, which includes a traditional single lenticular lens and an additional transparent layer. The focal length of the multi-layer lenticular lens can be changed by choosing the refractive index of the additional transparent layer to adjust the stereoscopic depth, and it is an easier and much more flexible way than changing lenticular lens's curvature radius. A 22-in. 9-view autostereoscopic display prototype was developed. The image crosstalk of the prototype is very small and it has good presentation to several viewers without wearing eyeglasses.     

Combined lenticular lens for autostereoscopic three dimensional display

When an autostereoscopic three dimensional (3D) display based on a single lenticular lens keeps working for a long period, the thermal expansion of lenticular lens results in serious crosstalk and 3D image deterioration. To overcome this problem, a combined lenticular lens is proposed. The combined lenticular lens is composed of a single lenticular lens used in the traditional autostereoscopic 3D display, a transparent glue layer and a glass substrate. The design method of the combined lenticular lens and analysis of thermal expansion effect is given. A 42-inch autostereoscopic 3D display based on the combined lenticular lens is developed. The experiment results verify that the proposed combined lenticular lens effectively avoids the crosstalk and 3D image deterioration happened in the traditional autostereoscopic 3D display.     

Crosstalk elimination in multi-view autostereoscopic display based on polarized lenticular lens array

An autostereoscopic display composed of a directional backlight,an image display panel,a striped half-wave plate,and a polarized lenticular lens array is proposed.The directional backlight emitting the parallel light can redirect the cones of light to lenticular lens array and reduce the chromatic spatial-interference effect.The striped half-wave plate,located in front of the image display panel,transformed the polarization direction of the lights from the directional backlight into two mutually perpendicular directions.The polarized lenticular lens array not only can divide the light from the left and right view images to send to left and right eyes but also can reduce the crosstalk of the stereoscopic images.The proposed autostereoscopic display can produce high quality stereoscopic images without crosstalk at the optimal viewing distance.     

Crosstalk reduction in multi-view autostereoscopic three-dimensional display based on lenticular sheet

A method to reduce crosstalk in multi-view autostereoscopic three-dimensional (3D) displays based on the lenticular sheet is proposed. Correcting the luminance values of each parallax image displayed on the display screen is employed. We analyze the causes of crosstalk. We deduce the formulas of crosstalk reduction according to the relationship between crosstalk coefficients of each parallax image observed through the lenticular sheet, luminance values of each parallax image displayed on the display screen,...