Liquid-crystal light valves

Liquid-crystal light valves have been built in which a relatively weak-signal image controls the flow of light to a much brighter projected image. The brightness of the projection light is limited only by heating in the light valve, and so great optical gain is possible. Brightness gains of 10?20 have been achieved with 30?W/cm2 of signal light at an efficiency of 15%. Resolutions of 5 line pairs per mm on the light valve and contrast ratios of 10:1 have been obtained, with a response time of about 0.1 s. With improvements, resolutions of 10?20 line pairs per mm relatively fast response and sensitivity to signal-light levels of nW/cm2 may be expected.     

Liquid-crystal light deflector

It is shown experimentally that the cell with an n-type nematic liquid crystal may have two functions, light deflection and shutter, and that the cell with a reflective coating film may deflect a light beam about twice the angle achieved with a transmission type of cell.     

Liquid-crystal color display by DAP-TN double-layered structure

A liquid-crystal display device is reported combining a polarizer, a deformation of aligned phases (DAP) cell, a twisted nematic (TN) cell, and an analyzer in series arrangement. The color of the transmitted light can be modulated by the application of voltage to the DAP cell. The transmission properties of the device can be switched from the DAP mode for crossed polarizers to that for parallel polarizers by the application of voltage to the TN cell. This improves control of the transmitted color.     

Photoactivated birefringent liquid-crystal light valve for color symbology display

Aphotoactivated liquid-crystal projection display device that is based upon the field-effect mode of the liquid crystal has been built and tested. The device displays high-resolution dynamic color symbology by means of the optical birefringence of the liquid crystal. The colors that can be displayed simultaneously are white (with gray scale), blue, green, yellow, and magenta on a dark field. The imaging light power required to excite the device varies from 30-900 µW/cm²at 525 nm and the resolution obtained at an MTF of 50 percent is 40 lines/mm. The basic construction of the device is similar to the dynamic scattering photoactivated liquid-crystal light valve.     

Solid-state light valve

Recent developments in the solid-state light valve promise a high-quality projection display. The heart of the solid-state light valve is a cathode-ray tube which operates with a modulated and scanning write beam depositing charge on an electrooptic crystal target. The charge pattern on the target causes optical changes which result in modulation of an external light source. The tube incorporates an erase flood gun to control persistence of the display. This paper discusses an unique reflected light configuration with the target operating at reduced temperature and illustrates the resulting image performance. Accomplishments of contracts with Isomet Corporation on crystal targets of KD2P (potassium dideuterium phosphate) and with EDO, Ltd., on isomorphs of KDP (potassium dihydrogen phosphate) are included. Work being performed by the National Bureau of Standards on crystal perfection and electrode interaction is also presented. The paper concludes with a brief summary of various applications of the solid-state light valve concept, and a short synopsis of results obtained by others that support our enthusiasm for the device.     

Liquid-crystal bar-graph displays

Analog displays using the twisted-nematic mode have been constructed. Histogram or multibar displays are demonstrated. Within each bar, a narrow rectangular "vane" moves in response to analog voltages. These reflective displays offer low vane-width, sharp vane edges, and a highly legible white-on-black or black-on-white readout.     

液晶偏振型彩色投影

因为传统 LCD 投影系统各个光学元件的光吸收作用,所以光效率低,若未经偏振的输入光的光强I_o=100%,其输出光强则 I_(out)<20%。本文论述了一种大膜孔液晶偏振型彩色投影(LC-PCP)新概念,其功能元件偏振片、滤光片和光调制器均由液晶器件组成。因而跟传统 LCD 投影系统相比,LC-PCP 的光效率有明显地改进。     

Electron-beam addressed liquid-crystal light valve

A new light valve is described. The device is a cathode-ray tube (CRT) that incorporates a liquid-crystal cell as the electron-beam target. This light valve uses simple "slide projector" optics and has demonstrated initial (nonoptimized) performance of 512 × 512 line resolution and > 50:1 contrast ratio.     

平板型液晶波导显示器

本文描述的平板型液晶波导显示器,克服了正交电极结构液晶显示器的寻址局限性,其矩阵是用玻璃芯子/液晶包皮的波导来作列阵列、用与之正交的叉指形电极来作行阵列的,各个像素用光来寻址,寻址方式为一次一行。     

微分型液晶空间光调制器

本文介绍了基于横向电场电光效应的微分型液晶空间光调制器。写入光强度的空间变化梯度产生横向电场,使垂直排列液晶分子倾斜,发生双折射效应。纵向电场提高了写入速度及擦除速度。本文给出了微分型液晶空间光调制器的理论依据及初步实验结果。     

Liquid-crystal display prospects in perspective

The advantages of dynamic scattering liquid-crystal displays--extremely low power consumption, flexibility of size and format, color choice, and washout immunity--are not obtained without cost. Long life requires ac drive and hermetic packaging. The optical characteristics of dynamic scattering make it difficult to design a display that utilizes the liquid-crystal panel effectively under a variety of lighting conditions. Multiplexed drive is cumbersome at best, so cost of drive electronics for more than about four digits is higher than with competing display technologies. The development of twisted nematic displays will reduce drive costs and improve appearance although the changes will not be revolutionary. The large multiplexing capability or color variability of the alterable birefringence effect is offset by prohibitive manufacturing tolerances and narrow field of view. Led by low-power digital wristwatches, liquid crystals should achieve a substantial market in applications whose requirements match unique display properties. Effective penetration of the consumer mass market will await improved field-effect devices and reductions in semiconductor packaging costs.     

Liquid-crystal polarization stabilizers on fiber arrays

We have built polarization stabilizer arrays of ultrathin liquid-crystal (LC) polarization controller (PC) arrays and a tap-type photodetector array on a fiber array. The ultrathin (35-/spl mu/m-thick) LC cells are inserted into trenches cut across the fiber array, which is affixed to V grooves in a glass plate and are used to change the phase of 1.55-/spl mu/m lights from 0.5 to 3.9/spl pi/ with the application of less than 3 Vrms. Two cascaded ultrathin LC cells, where the directions of alignment of the LCs are rotated by 45/spl deg/ relative to each other, are capable of converting light with an arbitrary input polarization to the transverse electric (TE) or transverse magnetic (TM) polarization. We fabricated a multichannel TE- and TM-polarization stabilizer of the previously mentioned 16-channel LC PC array and a feedback system made up of a multichannel tap-type photodetector array, sheet polarizer, and a computer and analog-to-digital converters. Feedback control was applied to maximize and minimize the tapped light, to convert an arbitrary input polarization to TM or TE output polarization, and stabilize it in the given state.     

Liquid-crystal display with electrically controlled birefringence

Applications of electrically controlled birefringence of nematic liquid crystals to display devices are tested with a matrix-type letter-and-number indication system. Such a cell, with 35 × 35 elements, was realised without storage circuits. The display shows bright colours, especially red and green, for low operating voltages (< 20 V). The feasibility of a liquid-crystal matrix display with 100 × 100 points has been demonstrated in the laboratory.     

切变聚合物网络液晶光阀

针对向列型液晶光阀响应速度慢的问题,提出了一种工作在可见光波段的切变聚合物网络液晶光阀(SLCLV).通过测定其电光响应,这种切变聚合物网络液晶(SLC)的响应时间可达几个毫秒,比相同条件下的向列型液晶的响应速度提高了一个数量级,而且对厚度依赖性小.通过理论分析,提出了SLC的工作原理,介绍了工作在可见光波段的反射式电寻址SLCLV的制作过程.器件的制作工艺简单,可靠性高.在可见光-可见光图像转换系统中,测得这种液晶光阀的帧频可达500 Hz,分辨率为81p/mm.如果能进一步提高制作工艺,这种液晶光阀在高速光学信息处理方面有广阔的应用前景.     

新型MEMS器件-光栅光阀(GLV)的原理及应用

MEMS(微机电系统)器件可同时结合机械功能和电子电路,一般采用半导体工艺来制造从微米到毫米级的器件.MEMS器件的应用范围非常广泛,包括传感器、液体力学、光学、RF、存储和生物技术应用.     

Tomorrow's TV - the grating light valve

The host of technologies tussling to displace the CRT have yet to face one strong contender: the grating light valve (GLV). This paper describes the construction and operation of GLVs which are MEMS technology electrostatically operated ribbon-shaped mirrors. Their main application, also outlined in this paper, is in large sized, high quality laser projection displays.     

Liquid-crystal technique for observing integrated-circuit operation

A nondestructive technique has been developed that enables both the electric fields and temperature distributions at the surface of an operating integrated circuit to be viewed with conventional optical microscopes. Packaged chips or unscribed wafers are coated with a nematic liquid-crystal layer and operated in their normal fashion. Practical preparation and observation procedures have been developed.     

中文液晶图文显示器及其应用

OCMJ2X8是1种内含GB2312国标1级简体汉字库的图液晶显示模块，该模块由于片内含有中字库，同时采用了简单的REQ／BUSY2线握手通信协议，使得由该模块构成的显示电路具有软件编程简单、容易，硬件接口相对简单的特点。中给出这种液晶模块的性能特点、接口协议及用户命令，并给出与AT89C52单片机的硬件接口电路及相应程序。     

Design of an electrooptic light valve projection display

A display device, e.g., projection TV, can be made by scanning, with an electron beam, a large sheet of electrooptic crystal in a light valve configuration. The design equations indicate the following. 1) The transfer function will be reasonably linear. 2) The resolution measured at the crystal will be the order of two TV lines per crystal thickness at 15 percent sine; wave response. 3) The output light spectrum can be nearly white. 4) Writing rates of the order of 10 MHz are feasible with conventional high-resolution CRT electron guns. 5) Large screen image brightnesses of the order of 40 to 50 fL are obtainable with xenon arc lamps and f/l collimator lenses. 6) Image contrast will generally be limited by the polarizer-analyzer quality. The electrooptic crystals must be several hundred millimeters in diameter and several tenths of a millimeter thick. Obtaining such crystals is the most serious obstacle to device construction.     

DEVELOPMENT OF AMORPHOUS SILICON LIQUID CRYSTAL LIGHT VALVE

Using the amorphous silicon (a-Si:H) film, which is cheap and has a small time lag, as the photoconductive layer of the liquid crystal light valve(LCLV) is an ideal selection. With the method of impedance matching used, we have designed and fabricated an a-Si:H LCLV and have obtained a clear image on a large screen projection system. The resolution of the valve was 20 lp/mm. The sensitometry measurement showed that the projection light level varies linearly with the writing light level when the latter is below 100 μW/cm2. The measurement of the transient response at the writing light level of 100 μW/cm2 indicated that the rise time and the decay time were 60 ms and 80 ms, respectively.