32×32矩阵式FED的驱动电路

FED( Field Emission Display)是一种新型的平板显示技术 ,本文简要介绍了其基本结构、工作原理和驱动电路 ,并给出了一种在 FED开发过程中用于展示和分析显示屏的二极管结构的驱动电路。该电路可以驱动 3 2× 3 2矩阵式FED显示屏 ,进行动态字符显示和简单的动态图像显示 ,采用脉宽调制的方法来实现 1 6级灰度 ,其动态扫描的占空比为 1 /3 2     

基于STV7610芯片的FED显示屏驱动电路设计

介绍了STV7610芯片的功能,具体阐述了用其作为FED(场致发射显示器)的驱动芯片的驱动电路实现以及相应的FPGA(现场可编程门阵列)控制电路,并对整体设计进行仿真和功能验证.采用FPGA对STV7610芯片进行控制和数据处理,可以实现对FED的灰度调制.采用将行数据划分子场的驱动方法,充分利用了PDP(等离子显示屏)驱动芯片优越的高压驱动特性,提高了驱动电路的整体性能,对现阶段FED驱动电路的集成化具有重要意义.     

FED新型灰度调制系统的研制

描述了FED新型灰度调制系统的构成,采用PDP驱动芯片uPD16347,利用其优越的高压驱动特性,通过FPGA模拟PWM进行控制,实现FED屏的驱动,本文还引入了误差扩散法,阐述了其在FED新型灰度调制系统中的作用,对现阶段的FED驱动电路的设计具有重要的意义。     

一种类OLED驱动的FED驱动电路的设计

通过与有机发光二极管(Organic light emitting diode,OLED)显示驱动电路的比较,得出了场致发射显示器(Field emission display,FED)驱动电路的特征,并在此基础上设计了基于简单IC与专用IC芯片的驱动电路,为FED驱动电路的实际应用提供了一种切实可行的思想方案.     

基于小波包变换的FED驱动电路故障诊断

根据FED驱动电路的特性,提出了一种小波包变换和神经网络相结合的方法,并将其应用于FED的驱动电路故障诊断.首先采用小波包变换对电路输出节点的电压信号进行分解,提取各频段的能量作为故障样本输入神经网络.仿真实验证明,该方法减少了故障诊断的时间,提高了故障诊断的准确率,使准确率达到87.17％.     

大屏幕FED功率集成系统的研制

介绍了场致发射显示器(FED)驱动系统的工作原理,并根据人眼视觉特性与FED光电效应,提出了适用于FED的自动功率控制(APC)方案.论述了SVGA级彩色FED功率集成系统的研制,包括前级APC模块和后级高压驱动模块.通过采用专用集成网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FED功率集成系统.实验证明,FED功率集成系统能够有效驱动63.5 cm(25 in)彩色印刷型FED显示屏,图像清晰,系统稳定、可靠.     

彩色FED自动功率控制方法的研究

从FED系统功率构成入手,提出了采用软件方式减小驱动电流,引入适用于FED驱动电路的自动功率控制(APC)方案,并根据灰度与亮度的关系对高灰度的像素点进行处理.实验证明,这种自动功率控制方法有效地降低了驱动电路的电流和整机功耗,提高了系统的稳定性.     

一种16×16点阵纳米金刚石FED驱动电路的软件设计

文章介绍了FED驱动系统字符点阵显示原理,针对纳米金刚石FED特点,设计了扫描显示程序,运用汇编语言编写了软件程序,在Keil μVision3环境下进行编译和调试,通过XLISP下载软件下载到驱动电路的单片机中对单片机进行控制口的控制,最后在LED屏上显示了一些汉字效果,验证了所编软件的扫描程序,进而验证了所设计的纳米金刚石FED逻辑控制电路的正确性,为金刚石FED驱动电路的商品化奠定了一定的基础。     

基于FPGA的FED显示器PWM灰度调制电路研制

介绍了场致显示器的灰度调制的原理及其灰度调制驱动电路的设计。采用FPGA控制技术实现前端视频信号接口、脉宽灰度调制的功能。通过串并转换模块与寻址芯片的连接，将PWM信号放大驱动FED显示屏实现视频图像的显示。该电路能驱动63．5cm彩色FED样机实现256级灰度显示。     

SAA7111A在彩色视频FED中的应用

介绍了增强型数字视频处理器SAA7111A芯片的主要性能，着重论述了彩色视频信号数字化技术以及在FED平板显示器件视频驱动电路中的应用。此电路方案已在25英寸彩色FED驱动系统中使用，为系统提供了优质的数字视频源，显示分辨率从QVGA到VGA，FED显示器获得了良好的图像显示效果。     

An Activity-Triggered 95.3 dB DR $-$75.6 dB THD CMOS Imaging Sensor With Digital Calibration

Imaging sensors are being used as data acquisition systems in new biomedical applications. These applications require wide dynamic range (WDR), high linearity and high signal-to-noise ratio (SNR), which cannot be met simultaneously by existing CMOS imaging sensors. This paper introduces a new activity-triggered WDR CMOS imaging sensor with very low distortion. The new WDR pixel includes self-resetting circuits to partially quantize the photocurrent in the pixel. The pixel residual analog voltage is further quantized by a low-resolution column-wise ADC. The ADC code and the partially quantized pixel codes are processed by column-wise digital circuits to form WDR images. Calibration circuits are included in the pixel to improve the pixel linearity by a digital calibration method, which requires low calibration overhead. Current-mode difference circuits are included in the pixel to detect activities within the scene so that the imaging sensor captures high quality images only for scenes with intense activity. A proof-of-concept 32 times 32 imaging sensor is fabricated in a 0.35 mum CMOS process. The fill factor of the new pixel is 27%. Silicon measurements show that the new imaging sensor can achieve 95.3 dB dynamic range with low distortion of -75.6 dB after calibration. The maximum SNR of the sensor is 74.5 dB. The imaging sensor runs at frame rate up to 15 Hz.     

A Simple and Effective Approach to Improve the Output Linearity of Switched-Current AMOLED Pixel Circuitry

Switched-current (S-I)-type pixel circuits are widely studied for high-performance active-matrix organic light-emitting-diode displays but suffer significant sampling and hold (S/H) nonidealities. In this letter, a simple and effective capacitive compensation method is proposed to suppress the S/H nonidealities and, thus, to greatly improve the current-reproducing accuracy and the output linearity of the circuits. The analysis procedure clearly demonstrates the operation mechanism of the method, and the simulation results of simulation program with integrated circuit emphasis prove its excellent applicability for S-I pixel circuits.     

Functional Pixel Circuits for Elastic AMOLED Displays

While fabrication of active matrix organic LED (AMOLED) displays on plastic substrates continues to face technological challenges, stable electrical operation of thin-film transistor (TFT) pixel circuits under mechanical stress induced by substrate bending remains a critical issue. This paper investigates strain-induced shifts in hydrogenated amorphous silicon TFT characteristics and the compound impact on TFT circuit behavior. Measurements show that the magnitude of the shifts is determined by the direction of current flow in the TFT with respect to the bending stress orientation as well as bias conditions. Physically based compact models are developed that relate device characteristics to material behavior for design and optimization of AMOLED pixel circuits that can maintain immunity to bending stress. In particular, current mirror-based pixel circuits are presented that compensate for the long term threshold voltage shift and instantaneous strain-induced shifts in device characteristics.     

Low-Power and Compact CMOS APS Circuits for Hybrid Cryogenic Infrared Fast Imaging

This brief presents a complete set of CMOS basic building blocks for low-cost scanning infrared (IR) cryogenic imagers. Low-power and compact novel circuits are proposed for single-capacitor integration and correlated double sampling, embedded pixel test, pixel charge-multiplexing and video composition and buffering. In order to validate the new basic building blocks, experimental results are reported in standard 0.35-mum CMOS technology for a 50 mum x 100 mum active pixel cell operating at 77 K. Based on the proposed circuits, IR imagers capable of capturing up to 256 x 2560 pixels at 25 fps can be implemented.     

电压倍增之像素设计

为了节省面板电路驱动芯片的功率损耗以及制作成本,本研究提出一种新的像素电路设计,而在设计中将会融合电荷泵电路。利用这种电路设计的像素可有效地将像素电极上的驱动电压提高到输入电压的2～3倍以上。此像素电路设计具有两个优势:第一,可以有效降低显示面板的像素功率损耗;第二,不需高电压的面板电路驱动芯片,因此可节省芯片的成本及功率损耗。由模拟结果可知,像素电极上的驱动电压确实可由此像素电路设计而提高到输入电压的2～3倍以上;而像素的功率损耗也可有效地降低,约为传统像素的1/2。     

Device and circuit level optimization for high performance a-Si:H TFT-based AMOLED displays

Active matrix organic light-emitting diode (AMOLED) displays with amorphous hydrogenated silicon (a-Si:H) thin-film transistor (TFT) backplanes are becoming the state of art in display technology. Though a-Si:H TFTs suffer from an intrinsic device instability, which inturn leads to an instability in pixel brightness, there have been many pixel driving methods that have been introduced to counter this. However, there are issues with these circuits which limit their applicability in terms of speed and resolution. This paper highlights these issues and provides detailed design considerations for the choice of pixel driver circuits in general. In particular, we discuss the circuit and device level optimization of the pixel driver circuit in a-Si:H TFT AMOLED, displays for high gray scale accuracy, subject to constraints of power consumption, and temporal and spatial resolution.     

Optoelectronic InP-InGaAs smart pixels for optical interconnectionsand computing

We describe InP-InGaAs optoelectronic smart pixels for applications in optical interconnection and computing. These circuits consist of monolithically integrated p-i-n photodiodes, heterojunction bipolar transistor (HBT) receivers and transmitters, and surface-bonded folded-cavity surface-emitting lasers (FCSEL's). Design, fabrication, and performance of two different circuits: a high-sensitivity pixel, and a high-bandwidth pixel with logic functions are discussed. We achieve a minimum switching energy of 6 fJ, a maximum pixel bandwidth of 800 MHz, and an optoelectronic gain of 3. To our knowledge, these are the best overall performance characteristics of any optoelectronic smart pixel technology and are competitive or superior to that achieved using all-electronic interconnects     

Accelerated stress testing of a-Si:H pixel circuits for AMOLED displays

Electronics reliability testing is traditionally carried out by accelerating the failure mechanisms using high temperature and high stress, and then predicting the real-life performance with the Arrhenius model. Such methods have also been applied to organic light-emitting diode (OLED) testing to predict lifetimes of tens of thousands of hours. However, testing the active matrix OLED thin-film transistor (TFT) backplane is a unique and complex case where standard accelerated testing cannot be directly applied. This is because the failure mechanism of pixel circuits is governed by multiple material and device effects, which are compounded by the self-compensating nature of the circuits. In this paper, we define and characterize the factors affecting the primary failure mechanism and develop a general method for accelerated stress testing of TFT pixel circuits in a-Si AMOLED displays. The acceleration factors derived are based on high electrical and temperature stress, and can be used to significantly reduce the testing time required to guarantee a 30 000-h display backplane lifespan.     

Low power design of a field sequential color LCoS chip

The low power design of a field sequential color （FSC） liquid crystal on silicon （LCoS） chip for near-to-eye application is presented in this paper. Dual power supplies are used in the design, that is, the supply for part of driving circuits is 3.3 V, and the one for the active matrix is 5.0 V. Serial-to-parallel conversion circuits are adopted to lower the pixel clock frequency of the chip. Also, an idle state is inserted into the pixel clock signal to decrease the switching activity factor to further reduce the power consumption. The LCoS chip is fabricated with 0.35 μm CMOS process and its power consumption is only about 300 mW.     

有源矩阵有机电致发光像素电路的研究进展

有源驱动方式的有机发光二极管（AMOLED）较之无源驱动方式易于实现高亮度和高分辨率、功耗更小,更适合大屏幕显示。但传统的两管驱动电路会出现驱动管阈值电压在整个屏幕上分布不均匀,或长时间加偏压后驱动管的阂值电压发生漂移。本文在两管驱动电路的基础上介绍了几种最近提出的补偿电路并描述了它们的改善效果及各自存在的问题。