Liquid Crystal Motion Picture Projector

ＬｉｑｕｉｄＣｒｙｓｔａｌＭｏｔｉｏｎＰｉｃｔｕｒｅＰｒｏｊｅｃｔｏｒ①ＳＨＩＹｏｎｇｊｉ（ＬｕｏｙａｎｇＴｅｃｈｎｏｌｏｇｙＣｏｌｅｇｅ，Ｌｕｏｙａｎｇ４７１００３，ＣＨＮ）Ａｂｓｔｒａｃｔ：Ａｌｉｑｕｉｄｃｒｙｓｔａｌｍｏｖｉｎｇｐｉｃｔｕｒｅｐ...     

液晶运动图像投影仪

由产生图像的液晶显示元件，投影图像的光学机构和显示屏即构成液晶运动图像投影仪。液晶材料可将图像信息暂时储存，称为储存效应。连续图像投影方法是，在液晶材料中产生图像并暂时储存起来，将投影光源对准液晶材料，然后作为液晶透射或散射光函数的图像投影到投影屏上，可连续地产生投影图像。     

Strain-biased ferroelectric-photoconductor image storage and display devices

A device suitable for image storage and display applications is described in which the image is stored as a spatially varying birefringence and can, by means of suitably polarized light, either be observed directly or projected onto a viewing screen. The basic device consists of a sandwiched structure of uniform thickness layers, comprising transparent electrodes, a photoconductive film, and a plate of fine-grained ferroelectric ceramic. In order to establish a preferred orientation of the polarization in the plane of the plate, a uniform strain is induced in the plate by placing it either in tension or compression ("strain biasing"). The plate then becomes birefringent, with the principal axes of the optical indicatrix along the strain axes. The magnitude of this birefringence can be controlled by an electric field applied in the thickness direction, and this forms the basis of the device operation. In operation, the image to be stored is projected or scanned onto the photoconductive film. A voltage applied to the transparent electrodes develops, in the ceramic, a transverse field having an intensity modulated by the photoconductive film. When the field is removed, the desired image is stored as a spatial modulation of the birefringence of the ceramic plate. To erase the image the entire structure is flooded with light in the presence of an electric field in the reverse direction, and the plate regains its initial state of uniform birefringence. A large number of experimental devices have been fabricated and tested in the laboratory. In addition to describing the basic device structure, experimental results are presented showing the level of performance obtained from present devices, and a physical interpretation of device operation in terms of domain switching processes is provided.     

Dmd-based autostereoscopic display system for 3d interaction

A novel approach to implement the multiview autostereoscopic display system is presented. This implementation brings together a high frame rate digital micro-mirror device (DMD) projector, an active shutter, and an optical wedge. It facilitates the modulation of the DMD to achieve extra high frame rate with a trade-off in greyscale resolution. The results have the great potential for commercializing the autostereoscopic display system.     

反射式液晶器件振幅调制特性的研究

研究了反射式液晶器件(RLCOS)的振幅调制特性.采用2×2的琼斯矩阵计算仿真,从理论上分析了它的振幅调制特性.实验采用He Ne激光为光源,将反射式液晶器件显示器作为液晶空间光调制器,用计算机和相关的电路系统驱动控制,并用CCD采样数据,测试了1024×768反射式液晶器件显示器的振幅调制特性.与未改形光束剖面相比,在特定的入射、出射偏振光配制下,可以用反射式液晶器件显示器来做振幅调制器.     

A silicon diode array scan converter for high-speed transient recording

A double-ended scan converter tube has recently been developed which uses a silicon diode array for the storage target. The purpose of the device is to capture high-speed single transients or low-repetition-rate signals and to retain the information until it can be read out at speeds slow enough for handling by conventional processing and display circuits. Improvements in wide-bandwidth deflection and the resolution of both writing and reading guns, combined with a charge gain of 2000 in the target, enables data to be stored at unprecedented rates. Information writing speeds of 2 × 10¹²tracewidths/s are possible with the device, sufficient for displaying a full-screen 2-GHz Sine wave. To reliably digitize the readout for signal processing, a signal-to-noise ratio of about 20:1 is required which the device, will provide at speeds up to 5 × 10¹¹tracewidths/s. Resolution at a 50-percent modulation level is 400 TV lines per horizontal scan (15.7 cycles/mm at the target).     

The mirror-matrix tube: A novel light valve for projection displays

A completely sealed-off electron beam-addressed light valve offering high reliability, low thermal impedance, and low-voltage operation is described. It is suitable for projection displays and is capable of producing bright high-contrast images with full gray-scale range and long-term storage. The light valve is contained as the faceplate in an otherwise standard, sealed-off 1½-in diameter vidicon tube and utilizes conventional focusing and deflection components. The target, which is fabricated of refractory materials using high-yield semiconductor-processing techniques, is composed of a dense matrix (500 elements/in) of aluminized silicon-dioxide membranes (~ 3000-Å thickness) which are supported centrally on small silicon posts (4-5 µm high) above a transparent sapphire faceplate. These flat, stress-free oxide membranes can be deflected electrostatically (up to 4°) when addressed with the electron beam. Thus an intensity-modulated display of the deposited charge pattern on the "mirror matrix" is produced when this type of light valve is used in conjunction with reflective schlieren optical arrangement, Mechanical and optical considerations have led to a special 4-leaf geometry of the mirror elements, enabling operation at low-voltage levels (175 V) and a high optical gating efficiency (~ 50 percent) to be achieved. Large-screen (2½-by 3½-ft) displays with up to 35-fL highlight brightness ( ×5 screen gain), 15:1 contrast ratio, and 400 TV lines resolution have been demonstrated. In addition, single-frame displays (1/30-s writetime) with full gray scale storage (of many hours) have been achieved. Preliminary studies using higher density mirror matrices (1000 elements/in) show that the display resolution can be extended to 600 TV lines/picture height.     

用于三片式数字光处理投影显示的新型分色结构

针对三片式数字光处理投影机光学系统中分色合色结构复杂、重量大、后焦距长的问题,提出了一种利用一个分色棱镜和两个二向色性滤色片来实现分色合色的方法。数字光处理投影机所用的光调制元件是数字微镜器件DMD,它是利用转动微反射镜改变反射光束的出射方向来实现光阀作用的。基于这一特点,通过精心安排分色棱镜和合色片的空间位置来实现对照明光束的分色以及对调制光束的合色功能。系统光学元件重量仅36 g,通过软件模拟本系统具有良好的色彩还原能力,光利用率达60%,还具有结构简单,对比度高等优点。     

An electron beam activated switch and associated memory

A new type of electron beam activated switch (EBAS) is described which utilizes electron beam induced charge storage in the metal-oxide-semiconductor (MOS) system. The state of the EBAS is determined by monitoring the surface conductance of the semiconductor. After discussing the basic charge-storage phenomena, memory arrays that use the electron beam for storing and reading information are described. A matrix array of EBASs in which information is stored using the electron beam and read by row-column access circuits is discussed in detail. The time to store a bit of information is a function of the current density of the electron beam; an approximate dosage of 10^-5C/cm²is required for storage. A memory design using Schlesinger's microspot tube for the electron optics is discussed. It is shown that storage of 1.0 × 10⁷bits per tube should be possible with presently available electron optical design and semiconductor technology.     

一种针对AMOLED器件劣化的电学补偿技术

AMOLED显示屏经过长时间的使用,不可避免地会有OLED器件劣化的问题。同一显示屏内不同位置的像素器件的劣化程度不同,造成显示屏整体亮度下降和显示残像。使用越久、亮度越高的像素,器件劣化就越严重。本文提出一种电学补偿技术,用以改善OLED器件劣化造成的亮度下降和显示残像。采用电学侦测的方法获得各个像素的OLED器件的VTH,将其存储于闪存芯片内,显示时通过查找表找到对应的OLED发光效率,计算得出各个像素的补偿后灰阶值,实现实时补偿的效果。本技术可以使劣化越严重的像素,获得越大的像素电流,从而弥补由于劣化造成的发光效率下降,最终得到理想的像素亮度。使用该方法可以补偿由于OLED劣化造成的亮度下降和显示残像,残像指标JND小于3.1。     

TV projection display using an amorphous-se-type Ruticon light valve

A display system is described which uses a new high sensitivity a(amorphous)-Se-type Ruticon and projects TV-like images from a conventional 9-in diagonal monitor onto a 40 × 40-in screen. The a-Se-type Ruticon requires 200-400-V dc bias, <15- erg/cm²input exposure, and it is capable of a factor of 10⁶light amplification in real-time operation. The device has an intrinsic image development time of 10²erg/cm². Typically, image erasure requires 4 ms. The readin optical system of the projector consists of the TV monitor, which is imaged with anf1.4lens onto the photoconductor side of the Ruticon. The system uses no mechanical shutters, and image erasure is accomplished with exposure from a flash tube. Readout is performed with a schlieren system using anf2.0projector lens, and a 360-W tungsten halogen lamp and a high gain screen. The readout optical system is capable of producing a maximum of 8.8 fc and 22:1 contrast ratio. Actual output brightness and contrast ratio in real-time operation are limited by the performance of the light valve. The image-storage characteristic of the Ruticon introduces brightness nonuniformity to the projected image.     

立体点阵式LED显示屏设计与实现

为满足某些实际应用场合对立体显示的需求,降低设计成本,设计了彩色立体LED显示屏。采用8*8*8共512个高亮LED灯组成正方体,通过单片机控制LED灯的亮灭时间,按面扫描,显示预设的文字和图形。分析了扫描方法并给出了PWM调制灰度算法,给出了系统设计方案和硬件原理图,制作出了硬件作品,进行了软件编程调试。实测结果表明：采用512个像素点,可清晰显示不同的图形、文字,实现了8级灰度控制,制作出绚丽的立体效果。     

The electrostatic storage display tube

The electrostatic storage display tube is a special vacuum tube which combines the intrinsic charge-storage property of a dielectric membrane with the high-speed high-resolution capability of a newly developed electron gun and an independent optical system to provide bright high-contrast large-screen displays. Writing and recording functions have been completely separated from the actual display function, thus providing several advantages over conventional storage display tubes. The same tube may be used for either theater-size displays or hard-copy outputs on photosensitive media. Four phases of the tube are covered in this paper: its basic characterstics, construction, applications, and preliminary speculations on reliability.     

A portable image overlay projection device for computer-aided open liver surgery

Image overlay projection is a form of augmented reality that allows surgeons to view underlying anatomical structures directly on the patient surface. It improves intuitiveness of computer-aided surgery by removing the need for sight diversion between the patient and a display screen and has been reported to assist in 3-D understanding of anatomical structures and the identification of target and critical structures. Challenges in the development of image overlay technologies for surgery remain in the projection setup. Calibration, patient registration, view direction, and projection obstruction remain unsolved limitations to image overlay techniques. In this paper, we propose a novel, portable, and handheld-navigated image overlay device based on miniature laser projection technology that allows images of 3-D patient-specific models to be projected directly onto the organ surface intraoperatively without the need for intrusive hardware around the surgical site. The device can be integrated into a navigation system, thereby exploiting existing patient registration and model generation solutions. The position of the device is tracked by the navigation system's position sensor and used to project geometrically correct images from any position within the workspace of the navigation system. The projector was calibrated using modified camera calibration techniques and images for projection are rendered using a virtual camera defined by the projectors extrinsic parameters. Verification of the device's projection accuracy concluded a mean projection error of 1.3 mm. Visibility testing of the projection performed on pig liver tissue found the device suitable for the display of anatomical structures on the organ surface. The feasibility of use within the surgical workflow was assessed during open liver surgery. We show that the device could be quickly and unobtrusively deployed within the sterile environment.     

The Light-Emitting-Switch Integrated-Circuit Display

A semiconductor display device utilizing arrays of light-emitting devices with inherent memory has been developed. The central element is a p-i-n device that exhibits current-controlled negative resistance and emits light in the high-conductance state. This light-emitting and switching device has been employed in a monolithic integrated circuit that permits the logic function in addition to the opticaf output function to be perfomed on the display surface. The circuit has been developed in a configuration that permits matrix address. This paper discusses the basic light-emitting switch and its utilization as a matrix display device and describes the development of an integrated structure employing the light-emitting switch and its incorporation into a complete display system. Modifications and improvements of the matrix display system based on this concept are also discussed.     

碳纳米管场发射显示器特性测试方法的研讨

通过低压化学气相沉积法在硅片上制作碳纳米管薄膜阴极,用真空荧光显示器的封装工艺,制备了碳纳米管场发射显示器样管。改变常用的驱动电源电压测试为器件电压测试,得到非常理想的伏安特性曲线和发光特性曲线。从测试结果分析可知,直接测量碳纳米管场发射显示器的器件电压和测试电源驱动电压所得结果是不同的,用后者代替前者不够合理。从电子场发射的角度看,实际的碳纳米管场发射伏安特性曲线应比测试的伏安曲线更陡。     

基于射影变换的结构光测量系统中投影仪标定方法

在结构光三维轮廓测量系统中,对参数的标定是测量的首要关键技术,但投影仪参数的标定目前还存在着标定精度低等问题。提出了一种简便、高精度的投影仪标定方法,该方法通过投影圆点图案到一块本身带有圆形标志点的平板上实现。根据射影变换原理建立投影仪图像和摄像机图像的基本对应关系,然后对基本对应关系的误差使用二元四次函数拟合并进行补偿的方法建立两者的准确对应关系,进而获得平板上圆形标志点在投影仪上的准确图像坐标,完成投影仪标定。仿真和实验结果表明,提出的投影仪标定方法有较高的精度,其中实验验证投影仪标定误差最大值小于0.1pixel,有效值小于0.03pixel,系统测量精度可达0.06mm。     

真空环境下低损耗高反射光学元件性能退化特性

为了研究真空环境对光学薄膜的影响,将离子辅助沉积制备的1064nm强光反射膜样品放置于真空度优于1×10^-5Pa的不锈钢真空室,实验观测其反射率和吸收损耗随放置时间的变化。结果表明,样品在真空环境放置335h后,其反射率从99.9823%下降到了99.9543%,吸收损耗从6.8×10^-6上升到了59.5×10^-6,用酒精乙醚混和液擦拭后其光学性能完全恢复,样品表面的污染层厚度随时间增加;操作过程中的人为因素是导致强光反射膜元件光学性能持续下降的主要原因。这一结果对高能/高功率激光光学元件在真空应用环境中稳定性的提高是有帮助的。     

Spatially antibunched semiconductor laser beam forsub-shot-noise-limited apertured transmission

It is shown that, using a semiconductor laser, one can generate spatially antibunched light. This light displays a smaller variance when measured over finite spatial regions than light from a classical source. In analogy with the common (temporal) amplitude-squeezed light, which possess photon statistics that are more regularly spaced in time than a Poissonian, this spatially amplitude-squeezed light produces a beam having photon statistics that are more highly correlated across its transverse extent than the typical (having Poissonian detection statistics) laser beam. One may have a spatially amplitude-squeezed source which does not display temporal squeezing, and one may have a temporally amplitude-squeezed source which does not display spatial amplitude squeezing. The possibility of having both forms of amplitude squeezing simultaneously is considered and such a device, using semiconductor laser technology, is proposed. Analysis reveals that there is indeed a quantum correlation between different segments of the beam. This spatially antibunched light suffers less signal-to-noise degradation when spatially partitioned in the object or subsequent image planes, making it potentially superior in spatial light modulation, free-space transmission, or imaging applications     

A simplified direct-viewing bistable storage tube

A simplified meshless storage tube has been developed which uses a single-layer dielectric storage target deposited over a transparent conductive coating on a glass faceplate. The dielectric layer serves the two principal purposes of bistable charge storage and production of the visible image. The mechanism of writing, storing and erasing depends on the well-known bistability of a good secondary emitting surface under flood current bombardment. The occurrence of an upper and lower stable potential is used here, as in previous bistable devices, to form light and dark image areas having a sharply defined boundary between them. This boundary is, in bistable tubes in general, an inherently unstable region because it has a high gradient across it, which tends to move the boundary across the face of the target. The principal new structural feature of the storage target is the formation of a semicontinuous porous dielectric layer which will not sustain migration of the boundary of the stored charge image transversely across the target surface, because of the electrical and mechanical discontinuity of the target microstructure. Another target is described in which image boundary migration is inhibited by the formation of the target dielectric in a pattern of islands or dots. The semicontinuous layer and the dot target each prevent image spreading and result in a substantial stable range of operating voltages of the collector electrode. The flood current collimating system is described, as is the erase pulse, the split screen, electrical readout, the integration mode, and measurements of the potential on the vacuum side of the storage dielectric. The dependence of brightness, contrast, resolution, writing speed, and stable range on target thickness is also described.