Three-electrode-per-pel AC plasma display panel

A new ac plasma display technique is described in which the alternating sustain function is achieved on the back or substrate glass surface and thex-yselected write-addressing uses a transparent front cover electrode and a substrate electrode. The three-electrode-per-pel structure achieves high overall emission efficiency as a result of nonshielded sustain discharges and low electrode capacitances.     

A hybrid liquid-crystal display with a small number of interconnections

A numerical display cell (nine digits of seven segments) with nematic liquid crystals can be driven in a dynamic or a static mode. The static mode combines a flicker-free display with optimum contrast, but it has the drawback of a large number of interconnections (63). This paper describes a method to reduce this number to only four: a 63-b buffer memory in the form of an I²L shift register is attached directly to the glass plate carrying the electrode pattern. The required transparent electrode patterns provided with metallized contacts are prepared by means of thin-film techniques.     

Electroosmotic display device

A black-matrix-type electroosmotic display (EOD) device is described. It makes use of a transparent porous substance with fine dot-shaped depressions on its surface and whose pores are filled with a transparent liquid with a high electroosmotic mobility. The device is manufactured using an embossing process and conventional printing techniques. The principle of operation involves electroosmotic movement to control the wetting of the depression's sloped surfaces on the porous substance. Characteristics of the EOD device are presented and a multicolor experimental numerical display is described. The EOD device has a relatively fast response time and low power consumption (less than 10² μW/cm²)     

Performance characteristics of nematic liquid crystal display devices

Display devices using nematic liquid crystal materials offer advantages over other display media in low-voltage low-power operation, cost of materials and fabrication methods, electrical compatibility with MOS drive circuits, and flexibility of character size and format. This paper describes liquid crystal display devices that utilize dynamic scattering to modify transmitted or reflected light. We have synthesized individual materials that have nematic temperature ranges as large as -15-115°C without super-cooling effects at low temperatures. When these materials are used in transmissive displays having liquid crystal layers 12 µm thick sandwiched between transparent electrodes, contrast ratios of 30:1 to 50:1 are realized at 10-40 V dc or ac with a current density of ∼1-10 µA/cm². Turn-on times are 10-50 ms and turn-off times are 30-100 ms, precise values being dependent on the specific material, temperature, and voltage used. The contrast ratio versus voltage exhibits a threshold so that it may be possible to matrix address liquid crystal display panels. Operating lifetime and display applications are also discussed.     

Large Area Flat—screen Liquid Crystal Television

A modular flat-screen liquid crystal television display is described.The picture elements of the modules may be emissive ,reflective or transmissive .The flat-screen liquid crystal television also comprised of an electrical control circuit capable of categorizing incoming television picture signals corresponding to the modules in the array and directing the electrical signals to the drive circuits of each module according to the portion of the television picture to be reproduced by the picture elements of that module.The picture elements are preferably formed in a light modulating film composed of a liquid crystal dispersion in a polymeric binder.A color display was also produced by placing a patterned red-green-blue filter adjacent the active matrix so that each picture element could also be coordinated with the color components of a color video signal.     

Large Area Flat—screen Liquid Crystal Television（continued 1）

A modular flat-screen liquid crystal television display is described .The picture elements of the modules may be emissive ,reflective or transmissive .The flat-screen liquid crystal television also comprised of an electrical control circuit capable of categorizing incoming television picture signals corresponding to the modules in the array and directing the electrical signals to the drive circuits of each module according to the portion of the television picture to be reproduced by the picture elements of that module.The picture elements are preferably formed in a light modulating film composed of a liquid crystal dispersion in a polymeric binder.A color display was also produced by placing a patterned red-green-blue filter adjacent the active matrix so that each picture element could also be coordinated with the color components of a color video signal.     

Thermal Modeling of a Hybrid Thermoelectric Solar Collector with a Compound Parabolic Concentrator

In this study radiant light from the sun is used by a hybrid thermoelectric (TE) solar collector and a compound parabolic concentrator (CPC) to generate electricity and thermal energy. The hybrid TE solar collector system described in this report is composed of transparent glass, an air gap, an absorber plate, TE modules, a heat sink to cool the water, and a storage tank. Incident solar radiation falls on the CPC, which directs and reflects the radiation to heat up the absorber plate, creating a temperature difference across the TE modules. The water, which absorbs heat from the hot TE modules, flows through the heat sink to release its heat. The results show that the electrical power output and the conversion efficiency depend on the temperature difference between the hot and cold sides of the TE modules. A maximum power output of 1.03 W and a conversion efficiency of 0.6% were obtained when the temperature difference was 12°C. The thermal efficiency increased as the water flow rate increased. The maximum thermal efficiency achieved was 43.3%, corresponding to a water flow rate of 0.24 kg/s. These experimental results verify that using a TE solar collector with a CPC to produce both electrical power and thermal energy seems to be feasible. The thermal model and calculation method can be applied for performance prediction.     

A true three-dimensional display

A new three-dimensional (3D) display concept is described that employs a random accessed flying spot in a transparent volume of material viewable from any position outside the volume. Arbitrary, true 3D figures may be presented ranging from line to full surface drawings and including alphanumerics. The display has a multicolor capability, continuously variable intensity, and can exhibit fixed or moving objects with good resolution. Display volumes of several cubic feet with high information capacity seem feasible.     

Particle on Bump (POB) technique for ultra-fine pitch chip on glass (COG) applications by conductive particles and adhesives

Chip on glass (COG) technology is widely used in liquid crystal display (LCD) modules for connecting driver ICs to the displays especially for middle and small size panels. The most common COG technology currently used in display applications is based on anisotropic conductive films (ACF). As the increasing demand in higher resolution and cost reduction, the bump pitch of the driver ICs becomes finer and finer. With the reduction of bump pitch, the current ACF based COG technology is confronted with two issues: one is the increase of the chances of open circuit; the other is the increase of the chances of forming shorts. A new approach for ultra-fine pitch chip on glass (COG) bonding, named ”Particle on Bump (POB)”, is proposed in this paper. In this technique, conductive particles are planted on the top surface of bumps of a driver IC through Au–Sn intermetallic connection. The driver IC is then assembled on the glass substrate of a LCD panel with an insulated adhesive by thermal press. The new method ensures that electrical connections are established only between bumps and corresponding pads. The Au–Sn reflow process for particle planting and corresponding COG bonding process were investigated in detail. The results showed that reliable connections were formed between particles and bumps through an Au–Sn intermetallic layer and final COG interconnections thus formed performed well in reliability tests. It is concluded that the POB technique overcomes the shortcomings of current ACF technique and has good potential to provide a viable ultra-fine pitch flip chip on glass solution for display applications.     

基于选择性湿法粗化方法制作n型欧姆接触的垂直结构发光二极管的电学性能研究

低阻和高稳定性的氮极性面N型欧姆接触对于GaN基垂直结构发光二极管尤为重要。研究发现,相对于未湿法粗化N型GaN面,湿法粗化N型GaN面的欧姆接触电阻较大,且最终制成的发光二极管具有较高的开启电压和较低的反向漏电。本文提出了一种选择性湿法粗化方法制作氮极性面N型GaN欧姆接触,基于此方法最终制成的垂直结构发光二极管具有更低的开启电压和反向漏电,并且输出光功率略有提升。进一步的老化实验表明该法制作的欧姆接触具有良好的稳定性。     

液晶含量对聚合物/液晶复合膜电光特性的影响--从正型向反型显示模式的转变

预聚物与正性液晶以适量配比合成的聚合物／液晶复合膜通常呈正型显示,即膜在关态时呈散射态,在开态时呈透射态。然而实验发现,用高的液晶配比合成的膜在适度电压驱动下能呈现反型显示,即这种膜在关态时呈透射态,在适度电压作用下呈散射态。在制膜过程中,如能将液晶做沿面取向处理,则膜的反型效应更加明显。用聚合物／液晶复合膜的反型显示机理,可开发出一系列新的光学显示器件。本实验研究了这种反型模式器件的电光特性,并建立相关的结构模型解释了实验结果。     

热敏液晶聚合物彩色图像显示器

描述了热敏液晶聚合物彩色图像形成和显示方法。在一定温度范围内,液晶聚合物能可逆地呈现透明与不透明光学态,使包含至少两种颜色的像素显示区域形成一个平面。显示器彩色区域内与彩色对应的像素可被选择,颜色的频谱传输中心位于被显示的各种颜色中,紧靠最长的波长。对被行距选中的像素加热,其最大不清晰度大于其它颜色像素的不清晰床。     

Electrical characteristics of a vertical light emitting diode with n-type contacts on a selectively wet-etching roughened surface

Low resistance and thermally stable n-type contacts to N-polar GaN are essentially important for vertical light emitting diodes(VLEDs).The electrical characteristics of VLEDs with n-type contacts on a roughened and flat N-polar surface have been compared.VLEDs with contacts deposited on a roughened surface exhibit lower leakage currents yet a higher operating voltage.Based on this,a new scheme by depositing metallization contacts on a selectively wet-etching roughened surface has been developed.Excellent electrical and optical characteristics have been achieved with this method.An aging test further confirmed its stability.     

Excimer-laser crystallized poly-Si TFT's with transparent gate

A new poly-crystal silicon thin-film transistor (poly-Si TFT) with a transparent bottom-gate electrode has been fabricated by XeF excimer-laser light irradiation from the glass substrate side. Compared with poly-Si TFTs made by XeF or ArF excimer-laser light irradiation to the top Si surface, the new TFT shows a higher electron mobility of about 100 cm²/Vs, independent of the Si film thickness. Therefore, poly-Si driver TFTs and amorphous-silicon (a-Si) TFTs for the matrix can be formed with the same channel-etch type bottom-gate structure simultaneously on the same glass substrate by using the same starting materials. This is expected to open the way for making driver monolithic and active matrix liquid crystal displays     

Surface roughening of SiC and Ga-containing semiconductors in reactive plasmas

Roughening of SiC and the Ga-containing semiconductors GaN, GaP, and GaAs is investigated in high-frequency reactive plasmas: in capacitively-coupled discharges at 13.56 MHz in a parallel-plate reactor and in plasmas driven by electron cyclotron resonance at 2.45 GHz. Objects to be roughened are rectangular slabs. With these devices, not only the surface which is directed rectangular to the electric field of the plasma sheath can be roughened but also the faces parallel to this field. As expected by high etch rates which exceed values obtained in argon by more than a factor of 20, processes in chlorine-containing plasmas are chemically dominated which causes partly crystallographic etching. The efficiency of the roughening process is demonstrated with high brightness GaN/InGaN LEDs on a transparent SiC substrate.     

Thermosensitive Liquid Crystal Polymer Color Image Display

A color image formation method is presented with thermosensitive liquid crystal polymers .The liquid crystal polymers are capable of reversibly assuming optical states of transparent and scattering lights ,and allow picture-element display areas in two colors at least to be composed on a surface,The picture elements within color areas are selected if they correspond to the color which is the spectral transmission center ,A heat is applied such that the maximum haze degree of the selected picture elements is greater than that of picture elements corresponding to any of the other colrs.     

A back-wafer contacted silicon-on-glass integrated bipolar process. Part I. The conflict electrical versus thermal isolation

A novel silicon-on-glass integrated bipolar technology is presented. The transfer to glass is performed by gluing and subsequent removal of the bulk silicon to a buried oxide layer. Low-ohmic collector contacts are processed on the back-wafer by implantation and dopant activation by excimer laser annealing. The improved electrical isolation with reduced collector-base capacitance, collector resistance and substrate capacitance, also provide an extremely good thermal isolation. The devices are electrothermally characterized in relationship to different heat-spreader designs by electrical measurement and nematic liquid crystal imaging. Accurate values of the temperature at thermal breakdown and thermal resistance are extracted from current-controlled Gummel plot measurements.     

应变液晶调光玻璃显示

介绍了聚合物分散液晶和应变液晶(SLC)的性质,SLC调光玻璃的结构特点,调光原理和光学特性以及制备方法。在SLC调光玻璃制备时,采用文字图案遮挡部分区域进行曝光,得到有文字图案的制品,遮光处形成透明状态,无遮光处处于散射状态。对制品施加剪切应力,散射区域变成半透明状态,文字图案消隐。依据此原理用SLC调光玻璃制作出一种特殊应力显示玻璃,可以开发成为节能的门窗等实用产品、在商场、公司以及酒店等场所装修上具有应用前景。     

透明液晶显示器色度特性研究

透明显示器适用于建筑物窗户、汽车车窗与商店橱窗等多种应用,除了原有的透明显示功能以外,还具有未来可能作为信息显示器的发展潜力,因而备受市场关注.但是目前厂商开发的重点仅集中在如何提高透明液晶面板的全光透过率,而对其色度特性研究却很少,导致在实际应用上全光透光率高的产品,其背后物品的色彩显示并不准确,应用效果不理想.在本文中,我们采用本公司量产的315UV2A透明液晶面板,对不同颜色光线通过透明显示器时的色度坐标偏移情况进行研究,确定了透明显示器对色度的影响.     

Light‐Driven Electrohydrodynamic Instabilities in Liquid Crystals

The induction of electrohydrodynamic instabilities in nematic liquid crystals through light illumination are reported. For this purpose, a photochromic spiropyran is added to the liquid crystal mixture. When an electrical field is applied in the absence of UV light, the homeotropic liquid crystal reorients perpendicular to the electrical field driven by its negative dielectric anisotropy. Upon exposure to UV light, the nonionic spiropyran isomerizes to the zwitterionic merocyanine form inducing electrohydrodynamic instabilities which turns the cell from transparent into highly scattering. The reverse isomerization to closed‐ring spiropyran form occurs thermally or under visible light, which stops the electrohydrodynamic instabilities and the cell becomes transparent again. It is demonstrated that the photoionic electrohydrodynamic instabilities can be used for light regulation. Local exposure, either to drive the electrohydrodynamics or to remove them enables the formation of colored images.