LCD用彩色滤色器的现状和进展

简要了ＬＣＤ用彩色滤色器研究的现状，报道了彩色滤色器市场和生产的变化情况，介绍了彩色滤色器研究发展的新动向。     

MVA模式TFT-LCD用彩色滤光片制程解析

彩色滤光片简称为CF,是TFT-LCD面板最主要的部件之一,其成本约占面板材料总成本的15%～30%.彩色滤光片的主要制程有BM的制作、RGB的制作、PS的制作、MVA体的制作.     

利用全彩LED和利用滤光器的颜色传感器的比较

颜色的自动识别在人们的生产和生活中有着重要的应用.近年来,TAOS公司推出的具有红、绿、蓝(RGB) 3种滤光器的TCS230光频探测器似乎已成为人们在构建各式颜色传感器时的最佳选择.本文报告一个利用全彩LED和TSL230光频探测器构建的颜色传感器.与目前流行的TCS230+白光LED组合的颜色传感器相比,本颜色传感器的RGB光源具有单色性,应能够更准确地识别颜色.     

利用微锥膜改善反射式液晶显示器件的视角

提出了一种可以改善反射式彩色液晶显示视角的微锥结构膜。模拟计算结果表明,当光从微锥的底部人射时,该膜起到准直作用,当光从微锥的顶部入射时,该膜起到散射作用。利用微锥膜可显著改善反射式干涉滤光膜的视角依赖性。由于微锥膜的作用不依赖了液晶盒结构,所以,可对多种结构的反射式彩色液晶显示有效。     

ATSC与DVB-T数字电视地面广播特性比较

我国的数字电视的发展已经取得了长足的进步，如何制定一个适合我国国情的数字电视地面广播的标准，仍需要广播工作者继续努力。本文介绍了ATSC 8－VSB和DVB－T COFDM两种数字地面发送系统在系统的C／N性能、频谱效率、噪声性能和干扰性能等方面的比较结果，两种系统各有优缺点，供大家参考。     

Design Considerations Between Color Gamut and Brightness for Multi-Primary Color Displays

Color displays show a vivid colorful image by combination of three or above primary colors on every individual pixel. Brightness of color displays, however, strongly restricts the color gamut of displays. From the color mixing theory, the area of color gamut on the color coordination would shrink smaller when brightness grows up. At the maximal brightness, displays can show one system white point only. The difficulties how to obtain the maximal brightness under an assigned color point or color gamut have been a key issue for display manufacturers. The paper proposes a theory to analyze the relation between brightness and color gamut based on the multi-primary color display. Simulations estimate the boundary of color gamut of multi-primary color displays under required brightness which had been proved by experimental results of tri-primary color display. The theory can be applied on the color temperature (CT) design which experimental results show the fact that a display apparatus with higher color temperature could sacrifice brightness less compared to one with lower color temperature when color temperature of the display image needs to change. The theory provides a design guideline for optimization between color gamut, color temperature and brightness on multi-primary color displays     

雷达抗干扰性能定量测试技术的研究

雷达抗干扰性能评估一直是一个技术难题,本文通过对信干比测量理论及信干比对雷达战术性能影响的分析,提出了一种适用于警戒雷达在对抗试验中抗干扰性能定量测试的方法,同时给出了测试系统在基地试验中的测量结果。     

Comparison Between DPCM and Hadamard Transform Coding in the Composite Coding of the NTSC Color TV Signal

Since differential-pulse-code modulation (DPCM) and orthogonal transform coding (OTC) are the most fundamental methods of high-efficiency coding (bit-reduction method), it is important to clarify the basic coding characteristics of these methods and the difference between them in order to utilize the bit-reduction method effectively. This paper theoretically as well as experimentally compares the coding efficiency of a DPCM having a two-dimensional predictor with that of a two-dimensional Hadamard transform coding method (HTC) in the intrafield coding of the NTSC composite signal. The comparison evidenced that the distinctive difference in coding characteristics between DPCM and HTC depends greatly on the power level of carrier chrominance signals. That is, it is confirmed theoretically and experimentally that the coding efficiency of the HTC is far lower than that of the DPCM in the case of a signal having a high power level carrier chrominance signal such as a color-bar signal.     

普通彩电与I2C总线控制彩电的差异分析

从普通彩电与I^2C总线控制彩电在控制技术方面的差异角度，提出了检修I^2C总线控制彩电应具有的数字逻辑思维观念。     

ATSC和DVB-T固定接收时的回波处理性能对比

地面数字电视广播传输美国标准ATSC(单载波)或欧洲DVB-T(多载波)在接收端都开发了回波处理技术。DVB-T在固定接收应用时,其解调器可利用时间域已知信息(由PN码的片断组成)进行0dB回波处理(类似ATSC),不依赖于保护间隔;因而,可采用1/32可选项;而DVB-T2则进一步把保护间隔扩展到1/128。简要介绍了ATSC和DVB-T固定接收时回波处理性能的对比。     

液晶显示器的现状与展望

本文介绍了电子显示器的发展,液晶显示器(LCD)、简单矩阵LCD和有源矩阵LCD的现状,以及LCD的发展趋势与展望。     

GaN基不同电极形状的LED性能比较

对前期工作中使用Crosslight APSYS软件模拟的6种优化电极的GaN基InGaN/GaN多量子阱蓝光LED芯片进行试制并测试分析,将实验结果与软件模拟结果进行比较,并进行可靠性分析。结果表明,优化电极的实验结果和软件模拟结果基本吻合,优化电极的光学、电学等特性的确有明显改善,芯片出光效率也有提升。对称型指形在光通量、光效和电压(电流为20 mA)等方面在这6种电极中最优;旋转形电极的寿命在预测中最高,为37 000 h,对称型指形位居第二;老化对优化电极的影响与未优化电极相差不多,所以综合考虑,对称型指形的性能最优。     

不同DTTB系统抗多径衰落的性能比较

介绍了数字电视地面传输(DTTB)标准中抗多径的方法以及ADTB-T系统在抗多径技术上的改进,通过截止率计算公式,仿真并比较了各系统的抗多径衰落的性能.     

齿轮传动与蜗轮蜗杆传动性能比较与消隙机构

就齿轮传动和蜗轮蜗杆传动2种方式进行较为详细的分析和比较,并计算了同一精度等级的齿轮副和蜗轮蜗杆副的传动副精度,结果显示由于传动形式不同使得蜗轮蜗杆传动副的综合误差要略低于齿轮传动副的综合误差。最后介绍了几种常用的消隙方式并进行比较。     

基于ICC标准的CRT色空问转换方法的研究与比较

分别采用阶调矩阵模型、多项式拟合、三维查找表和神经网络方法,建立CRT显示器设备颜色空间RGB与设备无关色空间的非线性对应关系,完成设备颜色显示的特征化.对两个常用的显示器进行了实验,并进行色差分析,比较了几种方法的精确度.对常用显示器的特征化实验结果表明:阶调矩阵模型色差居中,多项式拟合的方法精度较低,三维查找表和神经网络技术可以满足精度要求,其中神经网络方法最具优势.     

有线和无线通信技术的比较

描述有线与无线通信技术发展的情况，对于两种通信技术可以互为借鉴的部分重点进行了分析，也指出了二者的区别之处。从系统构成的角度给出了二者结合建网的实例。另外结合两种通信方式介绍了目前数字电视和3G技术的现状。     

Quantitative Comparison Between Dislocation Densities in Offcut 4H-SiC Wafers Measured Using Synchrotron X-ray Topography and Molten KOH Etching

Molten KOH etching and x-ray topography have been well established as two of the major characterization techniques used for observing as well as analyzing the various crystallographic defects in both substrates and homoepitaxial layers of silicon carbide. Regarding assessment of dislocation density in commercial wafers, though the two techniques show good consistency in threading dislocation density analysis, significant discrepancy is found in the case of basal plane dislocations (BPDs). In this paper we compare measurements of BPD densities in 4-inch 4H-SiC commercial wafers assessed using both etching and topography methods. The ratio of the BPD density calculated from topographic images to that from etch pits is estimated to be larger than 1/sinθ, where θ is the offcut angle of the wafer. Based on the orientations of the defects in the wafers, a theoretical model is put forward to explain this disparity and two main sources of errors in assessing the BPD density using chemical etching are discussed.     

Wi-Fi与WiMAX技术标准的比较分析

首先介绍了Wi-Fi联盟和WiMAX论坛，比较了Wi-Fi和WiMAX的产品特性参数；然后着重分析技术标准结构以及技术特点；最后展望它们的应用前景。     

一种基于免疫计算的IPS模型研究与设计

免疫计算是模仿生物免疫系统（BIS）具有的自学习、自适应、多样性、分布式并行处理等特点来解决工程问题。文章提出了一种基于免疫计算的IPS（入侵防御系统）模型,该模型利用BIS的机制,可以发现和处理一定的未知攻击,并利用多过滤器技术优化网络流的实时分析处理,提高了网络入侵防御的效率。     

Quantitative Comparison of Solid-State Microwave Detectors

A method for quantitative comparison of solid-state microwave square-law detectors is presented. The threshold response of the square-law detectors are compared for unit video bandwidth using the concept of noise equivalent power (NEP). NEP is the microwave input power required for unity signal-to-noise ratio in a 1 Hz bandwidth at the output of the detector. Contours of constant NEP in the microwave (RF) and video frequency plane clearly describe the dependence of threshold sensitivity on both video and radio frequencies, and thereby provide comparison of the threshold sensitivities of devices over the entire video and RF frequency spectrum. A criterion for the upper RF power lid of square-law operation for detectors is also presented. Dynamic range for a device can be found using this criterion and the threshold sensitivity of the device. Six solid-state detection devices are described briefly, then compared on the basis of the foregoing concepts. Four of these devices are familiar: the point-contact and planar Schottky-barrier ("hot carrier") diodes, and the tunnel and back diodes. Two relatively new devices are also discussed: the so-called "hot carrier" thermoelectric detector, and the space-charge-limited (SCL) dielectric diode.