共查询到20条相似文献,搜索用时 375 毫秒
1.
2.
本文围绕彩色显像管白场不均匀性问题,对偏转线圈上所采用的八极磁场及六极磁场彗差校正系统对白场均匀性的影响进行了对比分析与讨论,结果表明偏转线圈上所加八极磁场组件对光栅白场均匀性有较大的影响,其取舍是导致白场不均匀性的直接原因,在此基础上,给出了相应的解决办法。 相似文献
3.
1 色纯问题及相关原理1.1 色纯度定义三基色光栅中,某一基色不受其它两种基色混杂的程度,称色纯度。这里指的“混杂”包括混色(一种色场中混有另一种颜色)、偏色(色调不对)和白场深浅不匀。色纯不良是一个主观评价的指标,它在光电声色的测量指标中反映为“白场色度不均匀性”。随着顾客消费水平的提高和市场供求关系的改变,市场竞争的日益加剧,顾客对彩电色纯的要求越来越高。例如,前几年,对色纯度的要求,仅仅限于某一单色场中没有其它的颜色,但现在市场对这类问题越来越敏感,不仅不允许出现另外一种颜色,还不允许出现局部… 相似文献
4.
本文阐述了采用D65基准白(x=0.313,y=0.329)作为我国彩色电视机白场色温标准的理由,介绍了“D65基准白”及测量。 相似文献
5.
基于FPGA的液晶显示屏测试用标准白场装置 总被引:1,自引:1,他引:0
针对液晶显示屏生产厂商对标准白场的需求,研制了一种用于现场色彩标定的标准白场装置。介绍了标准白场装置的工作原理,以及该装置的标准定标和用户输出2种工作模式。针对标准白场装置的FPGA主控模块、显示器模块、人机接口模块、探头模块等主要硬件进行了详细说明。以内部显示模块状态机、机械按键去抖和LCM控制器为例说明了标准白场装置的软件设计。对研制的标准白场装置进行了标准定标实验,并对其定标后的性能进行了测试。实验结果表明:该标准白场装置可输出6 500、9 300K和12 500K3种色温的标准白场,具有不依赖标准光源、色温可调和数据存储等功能。标定后的标准白场装置能够生成色温可调的标准白场,24h内输出亮度误差小于0.5%。基本满足液晶显示屏生产厂商对标准白场装置的运行稳定可靠、操作简单方便、精度高等要求。 相似文献
6.
7.
8.
9.
10.
本文利用计及表面电荷的柱面结电场分布表达式,并根据场限环优化条件,首次建立了单场限环表面电荷效应优化模型,得到了考虑表面电荷效应后,优化单场限环洁构击穿电压以及优化环间距的归一化计算公式。分析了表面电荷密度对场限环结构耐压和优化环间距的影响,计算结果与文献中的数值模拟结果相符合,推得的公式可应用于场限环结构的实际设计。 相似文献
11.
12.
相干布局囚禁(Coherent Population Trapping,CPT)原子频标是一种功耗低、体积小、启动快的新型原子频标,温控系统是影响CPT原子频标稳定度指标的重要环节.本文介绍了通过优化设计实现CPT原子频标的高性能温控系统的方案.通过仪表放大器的应用提高了前端温度采集电路的温度分辨能力;通过小波分析算法对温度信号进行降噪处理;通过Δ-Σ算法实现脉冲宽度调制(Pulse Width Modulation,PWM),提高温控输出调节精度并减小谐波干扰.基于该方案实现了体积小、功耗低的温控电路,获得了较好的控温效果,改善了CPT原子频标频率稳定度指标. 相似文献
13.
本文对彩色显像管偏转线圈用两种六极场彗差校正系统进行了分析讨论,对垂直偏转场参量Vo,Vz的测量结果表明六极场校正系统的引入在偏转线圈颈部形成垂直枕形场有利于彗差的校正。同时,文中还对磁八极场对彗差的校正作用进行了分析。 相似文献
14.
15.
介绍了Thomson在CPT生产工艺中独特的滤光片,分析了其原理,提供了生产实践中的优化方法,以经验论的方法取代了繁琐的理论计算,并能迅速取得满意的最优化效果.此外还具体介绍了条纹式滤光片的工程实现--即在AutoCAD上用VBA进行编程实现母片图形制作. 相似文献
16.
The performance and optimization of switched diversity systems are considered. First, the one-dimensional distribution and probability density functions of the envelope of the received signal are obtained for three different switching strategies. This information is used to obtain the average probability of bit error for the case of non-coherent detection of binary FSK signals with Rayleigh fading envelopes and additive white Gaussian noise. The optimization of two of these switching strategies is then considered, and it is shown that by proper selection of switching thresholds, the average probability of bit error during detection can be minimized. It is also shown that these optimized switching strategies yield a significant improvement in performance over non-diversity systems and can approach the performance of more complex receivers such as maximal ratio combining. Computer simulations of switched diversity systems using a practical field model are used to verify the analysis. 相似文献
17.
随着显示器件技术的不断发展,传统显示器件正面临着新型显示器件的严峻挑战。作为传统显示器件的彩色显像管(简称CPT)如何应对这场挑战,并在激烈的市场竞争中立于不败之地,正是本文要讨论的话题。可以预言,CPT的薄型和超薄型化将是应对这一挑战的有效措施之一,也是CPT未来的发展方向。 相似文献
18.
The shape reconstruction of a perfectly conducting 2-D scatterer by inverting transverse magnetic scattered field measurements is investigated. The reconstruction is based on evolutionary algorithms that minimize the discrepancy between measured and estimated scattered field data. A closed cubic B-spline expansion is adopted to represent the scatterer contour. Two algorithms have been examined the differential-evolution (DE) algorithm and the particle swarm optimization (PSO). Numerical results indicate that the DE algorithm outperforms the PSO in terms of reconstruction accuracy and convergence speed. Both techniques have been tested in the case of simulated measurements contaminated by additive white Gaussian noise. 相似文献
19.
Zhang Q. Al-Nuaimy W. Huang Y. 《Geoscience and Remote Sensing, IEEE Transactions on》2007,45(2):410-417
The location and identification of unexploded ordnance (UXO) from magnetometer measurements have long been an area of active research interest. Ground surface methods, which are widely used for objects buried in shallow depths, become ineffective for objects deep in the soil because the object's anomalous field diminishes rapidly with distance, and interference by metal debris on the ground surface is significant. For the location and identification of deeply buried UXO, a total-field magnetometer equipped with a cone penetrometer technology (CPT) drilling system is employed in this paper. A novel inversion method is developed to extract information from individual and multiple CPT profiles. Compared with conventional inversion methods providing a single minimum as an estimate, this approach tests the likelihood distribution over the anticipated solution space, hence providing reliability. Real-world data are collected from a test site for the location and identification of a specific target. All experiments and simulations demonstrate the superior capability of this technique in solving real-world problems when only limited data points are available 相似文献