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.     

Liquid-crystal color light valve

A multilayer color display device employs two kinds of liquid-crystal films, One is a field-effect nematic liquid crystal; the other comprises a mixture of cholesteric and nematic liquid crystals that have the same function as circular polarizers used in place of crossed polarizers. Three colors (red, green, and blue) can be modulated independently by changing three voltages.     

A full-color matrix liquid-crystal display with color layers on the electrodes

A full-color matrix liquid-crystal display panel with color stripe layers of red, green, and blue on theY-electrodes is proposed. The color stripe layers of 300-µm pitch are made by photolithography. The color purities of greenish, bluish, and purplish colors obtained by the liquid-crystal display panel are as good as those of typical printed inks, while those of yellowish and reddish colors are poor at present. In addition, effects of the color layers on the display properties are discussed.     

Two-colour liquid-crystal display

A 7-segment numeric display with electrically controlled colour has been realised which uses the field-dependent birefringence in nematic liquid crystals. The colours obtained are very bright, especially the red and green.     

Matrix-addressed liquid-crystal display

In order to develop simple low-cost liquid-crystal matrix displays, 5 × 7 dots alphanumeric matrix display panels with 7 × 80 elements have been made and tested. A newly synthesized nematic liquid crystal, p-methoxy-p'-ethylazoxybenzene, was used in the panels as the major component of the liquid crystals. The crosstalk was found effectively suppressed by rubbing the surfaces of electrode glasses besides applying a blanking technique. Furthermore, storage-type liquid-crystal matrix display devices with 120 × 120 elements were also reported. Various mixtures of nematic and cholesteric liquid crystals were used depending upon the storage and erasing conditions required for the imaging.     

MBE-grown ZnSSe thin films on ITO substrates for liquid-crystal light valve applications

The MBE growth of ZnSSe alloy thin films on ITO substrates using ZnS and Se sources was studied and various structural and opto-electronic properties of the as-grown thin films were characterised. The XRD rocking curves resulting from these films indicate that the as-grown polycrystalline ZnSSe thin films have a preferred orientation along (1 1 1) direction. The evaluated crystal sizes as deduced from the FWHM of the XRD layer peaks were found to show a strong growth temperature dependence with the optimised temperature at about 290°C. TEM measurements done on these thin films also indicate a similar growth temperature dependence. The TEM cross-sectional micrograph of the sample grown at the optimised temperature shows a well-defined columnar structure whose nucleation seems to be highly correlated with the ITO grains. UV responsivity as high as 0.01 A/W and more than three orders of magnitude in rejection power for wavelengths longer than 450 nm have been achieved. It was also found that the sample grown at the optimised temperature has the lowest resistivity of 4.3×10¹¹ Ω cm, which provides a good match with that of a liquid-crystal layer. These results indicate that MBE-grown ZnSSe thin film is a promising candidate as the photoconductive material of liquid-crystal light valves for UV imaging applications.     

Tunable highly birefringent bandgap-guiding liquid-crystal microstructured fibers

A new type of nematic liquid-crystal infiltrated photonic bandgap-guiding fiber for single polarization or high-birefringence guidance is proposed. Numerical studies demonstrate that modal birefringence can be tuned by proper selection of the structural and material parameters as well as by the application of an external electric field in conjunction with the specific liquid-crystal anchoring conditions.     

Reflective multicolor liquid-crystal display

A reflective multicolor matrix LCD with micro color filters is investigated. In order to improve the brightness of the LCD, contrast and brightness of various liquid-crystal display modes are analyzed. This analysis suggests the choice of the phase-change-type guest-host mode. The optimal parameters for this mode are derived. In addition, the transmission spectrum of the micro color filters is investigated and the optimal doping concentration of the dye in the color filters is determined. This results in a reflective color LCD with acceptable brightness.     

A thin-film-transistor-controlled liquid-crystal numeric display

A thin-film-transistor-controlled liquid-crystal numeric display using vacuum-deposited CdSe TFT's is described. This display incorporates substantial on-substrate signal processing (level shifters, 4-bit latch, BCD-to-seven segment decoder) in addition to the display segment drivers. This is an MSI-level 150 TFT digital circuit which illustrates the level of display system integration that can be achieved using thin-film integrated-circuit technology.     

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.     

TV Image with liquid-crystal display

We present a complex liquid-crystal matrix display used as a TV screen. Its complexity is 128 × 128 and the multiplexing technique permits the display of 8 gray levels. The image change time is greater than 5 images/s.     

Mechanically bistable liquid-crystal display structures

This paper discusses two types of mechanically bistable liquid-crystal display structures, a previously reported type [2], [3] called vertical-horizontal, and a second type, called horizontal-horizontal. In both of them, the director configuration is planar. They are distinguished by the orientation of the director plane, which is perpendicular to the major surfaces of the device in the type called vertical-horizontal, and parallel in the type called horizontal-horizontal. In both types, the bistable states may be differentiated optically by use of a polarizer and dichroic dye, and switching is accomplished electrically by exploiting the dielectric anisotropy of the ordered liquid crystal states. We show calculations of the director configurations, their energy, and optical contrast of the bistable states. The bistable states are topologically distinct, so that the switching transitions are necessarily discontinuous in character. The movement of disclinations governs the switching process, and their detachment forms the basis of stability.     

A design of multiplexing liquid-crystal display for calculators

A numeric liquid-crystal display using the dynamic scattering mode has been developed for calculators by adopting a total system design through the integrated development of material, device, and system. A mixed Schiff-base nematic liquid crystal with the dopants of l-hexadecylpyridinum bromide and p-aminophenol has been developed for the 1:2 selection multiplexing drive over a wide temperature range (0-40°C). A reliable package has been achieved with new technology. A 1-chip CMOS driving circuit with a 42-lead package has been developed for 8-digit 7-segment numeric readout displays in order to eliminate the dc component of the applied voltage, to minimize variations in the drive voltage, and to reduce power consumption. The devices have passed severe reliability tests. Our displays have lasted 15 000 h under normal test conditions. Using the dichroic mirror approach, it has become possible to design color displays of yellow, green, blue, or any color which have high readability and wide viewing angle under severe ambient light conditions.     

Performance of thin-film-transistor-addressed liquid-crystal display circuits

The operation of thin-film-transistor (TFT)-addressed liquid-crystal (LC) display circuits is analyzed. The voltage on the storage capacitor in a simulated TFT-LC circuit is measured. TFT's fabricated in our laboratory have been demonstrated to be able to function satisfactorily in a TFT-LC circuit. The storage capacitor, thus the LC cell, can be charged to desired voltages within a line time and holds the voltage for one frame time under proper bias conditions. TFT's in a TFT-LC circuit perform differently from the dc condition. The dynamic ON current is higher and the dynamic OFF current is lower than the dc currents. Excellent dynamic stability in both on and off conditions is measured.     

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.     

Power reduction in liquid-crystal display modules

A method for driving a liquid-crystal display (LCD) which can reduce power consumption by up to 50 percent is described. While the drive method commonly used requires power-supply current both to charge and to discharge the display capacitance, the method described here allows the capacitance to be discharged by shorting the display electrodes momentarily.     

用液晶光阀实现大尺寸物体光学三维轮廓测量

提出一种用液晶光阀把计算机模拟正弦分布且具有一定榴移量的多幅干涉条纹投影到三维物体上，通过CCD采集被物体调制的变形条纹，在同一位置用计算机窗口来控制相移，实现对物体的光学位相三维轮廓测量，同时针对测量系统误差进行分析和讨论。     

An amorphous silicon triode rectifier switching device for active-matrix liquid-crystal display

A triode rectifier switching (TRS) device composed of two amorphous silicon (a-Si) diodes and one resistor has been demonstrated experimentally to be a good switching device for active-matrix liquid-crystal display (AMLCD). The output and transfer characteristics of a TRS are very similar to those of an a-Si thin-film transistor. High on/off current ratio (>5/spl times/10/sup 6/) and low off-state leakage currents (<0.4 pA) have been demonstrated with a-Si diodes and a-Si resistor, indicating that the TRS is suitable for high-performance switching devices for AMLCD.     

Mechanism of misalignment failure of liquid-crystal display devices

Misalignment failure mechanisms which are a problem in twisted nematic liquid-crystal display devices were investigated. A life test which changes the driving conditions of the applied multiplexing voltage was implemented for devices which use estercy-clohexane liquid crystals. The life tests showed that misalignment life is longer with a lower voltage, a smaller duty ratio, and a higher frequency. These results are highly appropriate for models with alternating current electrolysis of the liquid-crystal material. In addition, electrostatic capacity and applied voltage properties were used to study the relationship of liquid-crystal dielectric anisotropy and the coupling coefficient with temporal misalignment changes. The coupling coefficient decreases along with misalignment failure