高灰度视频OLED显示控制系统设计与应用

在详细分析AFD公司OLED面板电气特性和各种OLED灰度扫描原理的基础上,对AM-OLED扫描驱动电路进行研究,采用FPGA作为核心控制器件,完成了高灰度OLED视频显示系统设计。系统主要包括DVI接口信号处理模块、内存管理模块和灰度扫描控制模块,其中成像核心模块采用子场扫描工作方式;解码后的DVI信号经过一系列处理,可实时地送到OLED屏上显示,且灰度等级256级和64级可选。视频OLED显示系统实现了240×RGB(H)×320(V)QVGA分辨率,256级灰度显示,帧扫描频率为60～100Hz。电源驱动板共有7个电源输出,可根据外部环境来分别进行调节OLED屏的亮度,以实现OLED高灰度视频显示。     

自关闭脉宽调制OLED灰度控制系统的研究

根据有机发光显示器(OLED)的灰度显示特性,采用对像素的开启和关闭分别进行控制的策略,提出了基于存储器的自关闭脉宽调制(PWM)方法。给出了系统实现方案,完成了系统设计、仿真及FPGA实现。实验结果表明:在显示平板像素点数及灰度级相同的条件下,与传统基于比较器的实现方法相比,本文方法不仅具有同样的占空比和扫描效率,而且降低了系统硬件资源的开销,在节约芯片面积上具有明显的优势,有利于专用芯片性价比的提高;灰度控制系统应用于20×20pixel绿色无源OLED的驱动,能够正确完成16级灰度显示。     

12.7 cm彩色AM-OLED显示器分场驱动研究

研究分场数字灰度方案,以提高低温多晶硅（LTPS）有源驱动有机电致发光显示器（AM—OLED）的亮度均匀性和灰度精确性。随着显示器尺寸和分辨率的提高,驱动频率会呈指数上升,在保证各像素发光时间的前提下,采用数字信号处理（DPS）复合乒乓结构和双通道内存输出技术,实现了16级灰度的彩色12．7cm QVGAAM—OLED的动态视频显示。     

基于FPGA的VGA图像显示系统的设计

VGA(视频图形阵列)是一种标准的显示接口,被广泛应用。根据VGA,FPGA(现场可编程门阵列)的作用原理,设计的基于FPGA的VGA接口可以直接将数据送至显示器,同时增添了关于输出图像灰度等级的设计。与传统设计相比,该设计没有计算机的处理过程,可节省硬件成本,加快数据处理速度,被广泛应用到视频显示领域。     

256级灰度OLED驱动电路

设计了一种OLED矩阵屏的驱动电路,在64×48像素OLED矩阵屏上,采用脉宽调制的方法实现了256级灰度、无交叉效应的静态图案显示.通过在未选中行上施加正向偏压、未选中列上施加反向偏压的方法,有效地抑制了交叉效应.     

基于OLED灰度显示的新方法

介绍了有机发光二极管(OLED)技术特点、彩色实现方式和驱动方式.针对OLED灰度显示,介绍了实现灰度显示的两种常用方法即脉宽调制和帧灰度调制,并分析了各自的特点.在此基础上,尝试了一种新的方法,将二者结合起来共同实现灰度显示.这种方法不仅可以保持脉宽调制灰度显示的高速度,还可以保持帧灰度方式的均匀、稳定和足够的响应速度,而且可以大大提高灰度级别数.介绍了利用这种新方法实现OLED灰度显示数据的具体方式,该方法在硬件实现上简单易行,节约面积成本.     

AMOLED的图像缩放及时序控制方案

为研制中的分辨率为640×RGB×480的有源矩阵有机发光显示器(AMOLED)设计了图像缩放和时序控制方案。为了达到良好的显示效果且同时节省硬件资源,水平缩放采用基于边缘的插值算法,垂直缩放采用双线性插值算法;此外,利用图像缩小后产生的"行空白"时间增加写屏时间,避免了片外存储器的使用。FPGA验证结果表明,该方案可以实现64级灰度的VGA AMOLED的动态视频显示。     

VGA级大屏幕印刷型FED视频显示系统的研制

论述印刷型场致发射显示器驱动系统的工作原理,介绍了采用DVI、VGA视频接口技术、专用集成图像灰度调制和集成扫描电路接口技术以及FPGA控制等技术研制出了能驱动显示VGA分辨率的印刷型FED视频显示系统。该系统能显示各种彩色视频图像,图像亮度已达400cd/m2、对比度达1 000:1,电路灰度等级达256级,有效显示对角线尺寸为635 mm(25 in)。     

基于 AM-OLED 立体显示接口电路的设计

为了将PC机上的视频源在双AM-OLED微型显示器上实现立体显示,设计了立体视频显示接口电路。对该系统所采用的人眼的双目视差原理和SVGA050微显芯片立体显示功能进行研究。针对AM-OLED显示器的结构与特点,提出了双VGA接口为视频输入接口、PIC18LF2550为MCU控制芯片,双AM-OLED微型显示器的立体显示系统的电路设计方案;介绍了母版和OLED板的设计以及主控器利用IIC串行总线对各模块寄存器进行配置。介绍了立体显示功能实现的原理和配置SVGA050微显芯片的立体功能控制参数的方法。实验结果表明,通过对开发的立体显示系统进行左右格式的立体视频源播放测试,实现了视频源在双1.27cm(0.5in)、800×600分辨率SVGA050微显芯片上的立体显示。最后验证了基于AM-OLED微型显示器的立体显示接口电路设计方案的有效性。     

基于分形IP核的平板显示控制器设计与应用

论述了基于分形IP核的平板显示(FPD)控制器的设计与工程实现,所设计的分形扫描控制器可用于LED、OLED、TFT-LCD等平板显示器;平板显示系统由多媒体视频显示卡、以太网视频发送卡、分形扫描控制器及显示屏四大部分组成。使用高速以太网的物理层协议技术取代传统多芯差分长线数据传送,具有高速、长距离传输的优点;扫描控制器用FPGA实现,有效提高了成像灰度等级和画面质量。通过LED平板显示器的设计与实现,说明分形扫描IP核在FPD产业应用的可行性,以及对平板显示系统灰度等级、帧频等参数提高的贡献度。     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Nanoimprint Lithography -A Next Generation High Volume Lithography Technique

IntroductionNanoimprint Lithography is a well-acknowl-edged low cost, high resolution, large area pattern-ing process. It includes the most promising methods,high-pressure hot embossing lithography (HEL) [2],UV-cured imprinting (UV-NIL) [3] and micro contactprinting (m-CP, MCP) [4]. Curing of the imprintedstructures is either done by subsequent UV-lightexposure in the case of UV-NIL or by cooling downbelow the glass transition temperature of the ther-moplastic material in case of HEL…     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

Influence of PVK ： NPB hole transporting layer on the characteristics of organic light-emitting devices

A doping system consisting of NPB and PVK is employed as a composite hole transporting layer （CHTL）. By adjusting the component ratio of the doping system, a series of devices with different concentration proportion of PVK ： NPB are constracted. The result shows that doping concentration of NPB enhances the competence of hole transporting ability, and modifies the recombination region of charge as well as affects the surface morphology of doped film. Optimum device with a maximum brightness of 7852 cd/m^2 and a power efficiency of 1.75 lm/W has been obtained by choosing a concentration proportion of PVK ： NPB at 1：3.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.     

Analysis of error performance on Turbo coded FDPIM

Due to variable symbol length of digital pulse interval modulation（DPIM）, it is difficult to analyze the error performances of Turbo coded DPIM. To solve this problem, a fixed-length digital pulse interval modulation（FDPIM） method is provided. The FDPIM modulation structure is introduced. The packet error rates of uncoded FDPIM are analyzed and compared with that of DPIM. Bit error rates of Turbo coded FDPIM are simulated based on three kinds of analytical models under weak turbulence channel. The results show that packet error rate of uncoded FDPIM is inferior to that of uncoded DPIM. However, FDPIM is easy to be implemented and easy to be combined, with Turbo code for soft-decision because of its fixed length. Besides, the introduction of Turbo code in this modulation can decrease the average power about 10 dBm, which means that it can improve the error performance of the system effectively.     

A method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.