基于LabView的彩电白平衡自动测试系统

采用自行研制的高精度CRT光电探测器和可程控的白场信号生器，在PC机和LabView虚拟仪器平台上设计了彩电白平衡自动测试系统，这种在线自动测试仪器，适合东芝TB系列、三洋LA系列等机芯的I^2C总线彩电的白平衡自动测试与调整，在满足质量要求的前提下，具有快速和高通过率的特点。本文介绍该仪器的工作原理、硬件结构以及LabView图形化应用软件的设计方法。     

家用摄录机原理讲座 第九讲 摄像部分调整(下)

三、白平衡控制单元调整 (一)室内白平衡调整在更换固体摄像器件或信号处理集成块IC304等电路后,需进行室内白平衡调整。所用的调整仪器为矢量仪或示波器。 1.将白平衡操作开关设置在“INDOOR”(室内)档; 2.用跳线连接法,将处理电路板上的基准电压参考点TP511,分别同测试点TP512和TP513相连。把检测时用的反馈色差信号箝位在特定电平上,避免反馈信号对调整数据的影响;     

简讯

多色液晶显示器组件精工仪器和电子公司用电解淀积法在三色滤色器基础上研制成功一种带后光源的多色液晶显示器组件。红、蓝、绿三色象素组成160×64矩阵,显示器可产生红、蓝、绿、黄、紫、青绿、白和黑八种调色。点的尺寸为0.62×0.18(mm),象素为0.62mm~2。显示器长1(?).6mm,宽42.2mm,厚20mm。此液晶显示器组件包含一块 CMOS 大规模集成电路驱动器。显示器和驱动器功耗为200mW,显示器最大对比度为7.5。其结构如下图所示。     

液晶电视的白平衡调整

在液晶电视生产过程中,白平衡的调整是一个关键部分,目前大都采用PC机调整。现有调整方法一般只考虑色温的误差,但基本未考虑色差,所以,产品在显示不同亮度的白信号时有些信号的色差较大,影响电视的主观效果。提出了一种白平衡调整方案,采用PC机与彩色分析仪Chroma7120,通过曲线拟合的方法补偿色温差异,实现液晶电视白平衡的调整。实验结果表明该方案既方便又能满足白平衡的调整要求。     

如何处理索尼DSR-300AP数字摄录一体机成像不实

以索尼DSR-300AP为例,简要介绍1例故障,供同行参考. 　　1 成像原理 　　从镜头、分光镜、摄像管组件(分红、绿、蓝3路)以及各路的预防器板,200 nA的图像信号电流经前置预防器放大到0.4峰值后输出.为了减少图像的惰性沿分光棱镜引入背景光,预防器的输出包含因背景光投射到摄像管靶面而造成的信号成分.经红、绿、蓝各路预防器后输出的信号,送入视频处理器各部分.预防器上有增益选择、可变增益、红、蓝路的白平衡、γ校正、白切割、黑切割、彩色发生器等电路.由于采用了大规模集成电路,板上元件数量很少. 　　视频板G路信号的增益控制放大器输出给图像增强板,G路信号产生水平、垂直轮廓校正信号.所产生的轮廓校正信号从图像增强板输出,并回送到视频处理器板,与经过黑电平调整控制及γ校正后的红、绿、蓝信号混合,再经过各自的白、黑电平切割电路后送入编码板.经过处理和轮廓校正后的红、绿、蓝信号在编码板上编码,形成PAL制全电视信号,并送到录像机和监视器2个插座输出. 　　……     

可用于数码相机的新型滤色器实验研究

目前的数码相机获取彩色大多是由棋盘格状Ｂａｙｅｒ型滤色器与ＣＣＤ构成彩色成像器件获得。本文则提出了一种新型格式的滤色器,其不仅具有三原色空间周期采样的特点,同时又具有三色光栅编码的特点,即编码数字图像的频谱面上红、绿和蓝信号相互分离。本文的分析表明这种滤色器和Ｂａｙｅｒ型相比具有解码步骤较为简单的优点。本文特殊设计的模拟实验验证了其用于数码摄影的实际效果。     

一种新型I2C总线彩电白平衡自动调整仪

介绍一种采用独立仪器机箱，江集白场信号发生器、测量、自动调整、显示为一体的新型Ｉ＾２Ｃ总线彩电白平衡自动调整仪，适合东芝ＴＢ系列、三洋ＬＡ系列等机芯的Ｉ＾２Ｃ总线彩电的白平衡自动调整，它在满足质量要求的前提下，具有快速（７～８ｓ／台）和高通过率（９９．６％）等特点。介绍该仪器的调整原理、硬件结构以及仿真手工调整的自动调整策略等软件设计方法。     

液晶电视的白平衡调整

本文提出了一种白平衡调整方案,采用PC机与彩色分析仪Chroma7120,通过曲线拟合的方法补偿色温差异,实现液晶电视白平衡的调整。实验结果表明该方案既方便又能满足白平衡的调整要求。     

LCD显示器的白平衡调整

在液晶显示器生产过程中,白平衡的调整是一个关键部分,目前大都采用PC机调整。针对现有调整方法的不足,提出了一种白平衡调整方案。该方案包括了两个步骤,首先,利用LCD显示器自身的嵌入式平台实现输入信号和前端采样A/D的误差校正;然后,采用PC机与彩色分析仪Chroma7120,通过曲线拟合的方法补偿后端显示屏的色温差异,实现LCD白平衡的自动调整。实验结果表明该方案既方便又能满足白平衡的调整要求。     

家用摄录机原理讲座 第四讲 色信号处理电路

一、电路工作原理由于各种摄像机的摄像器件和滤色器的滤色形式各异,因而在色信号处理方式中也有所不同。本讲在分析MC-20机型色信号处理电路的同时,对采用MOS型摄像器件,并运用W(白)G(绿)、Cy(青)Ye(黄)滤色器的摄像机色信号处理通路作系统阐述。在色信号处理通路中,有些电路与亮度通路中的相应电路在名称、功能上基本相同;诸如,v校正电路、箝位电路,AGC电路、淡入淡出控制电路等等。另一些特殊工作电路,包括解调电路、色差信号形成电路和编码电路。在信号处理过程中还涉及到白平衡控制,及其它     

A microprocessor-based generator of synchronizing signal and test signal for colour TV

Test card for color TV is a widely used method to evaluate the quality of a TV set directly. We have made a test signal generator (which can also generate synchronizing (abbreviated to sync hereafter) signals) mainly based on microprocessor Z-80. Taking the advantage of microprocessor programming, combining with the technique of microprocessor, digital circuits and analogue devices, we use software as far as possible to generate signals directly or to simplify the controlling circuits. Those signals, such as composite sync signal, blanking signal and a series of test signals are originally realized by a number of sequential circuits and logical gates. Now, this test signal generator has smaller size, higher stability and lower cost compared with former ones which consist of more hardware. All of the programs are stored in EPROM. We can change the test patterns and their orders easily by changing the programs without changing the main structure of the system. On the other hand, varied kinds of non-standard TV sync signals and test patterns can also be obtained in this way.     

16：9宽屏彩电中的图像压缩技术

对于现有１６：９宽屏幕彩电在接收４：３幅型比图像时出现的水平失真现象,提出了一种有效的数字压缩技术,将亮度信号（Ｙ）,两个色差信号（Ｒ－Ｙ,Ｂ－Ｙ）进行数字化处理,按一定规则在存储器中进行信号的存取,实现图像在时间轴上的压缩,解决了图像的水平失真问题。     

16∶9宽屏彩电中的图像压缩技术

对于现有16∶9宽屏幕彩电在接收4∶3幅型比图像时出现的水平失真现象,提出了一种有效的数字压缩技术,将亮度信号（Y）、两个色差信号（R-Y,B-Y）进行数字化处理,按一定规则在存储器中进行信号的存取,实现图像在时间轴上的压缩,解决了图像的水平失真问题。     

A new CCD architecture of high-resolution and sensitivity for colordigital still picture

A new charged-coupled device (CCD) architecture developed for building high-resolution and high-sensitivity image sensors suitable for color digital still picture applications is presented. The sensor is based on the interline CCD structure. Both the interline pixels and the vertical charge transfer lines are utilized as light-sensing elements to improve simultaneously the resolution and sensitivity. This device is named the sea-of-photosensor array (SPA-CCD). A camera and supporting digital system were designed and built specifically to evaluate the device. Digital picture processing for white balance adjustment, chromatic correction, and high-frequency luminance was performed to improve color reproduction and picture resolution. An increased light sensitivity and limiting resolutions of 550 horizontal lines and 400 vertical lines on a TV screen were confirmed with an SPA-CCD of the same chip size as a conventional 190-k pixel IT-CCD. The new design of the SPA-CCD overcomes both the sensitivity and the resolution limitations of previous approaches     

Constant modulus algorithm for blind equalization of multipath transmitted video signals in cable networks

In this paper we present an approach to equalize multipath transmitted video signals without any reference signal. This approach takes advantage of the constant envelope feature of the color burst signal, which is transmitted in the blanking interval of each TV line and can be considered as an angle-modulated signal. The constant modulus algorithm (CMA) after Treichler is modified for our purpose. Special attention is given to the equalization of video signals in PAL systems. By making full use of the genuine phase feature of the color burst signal in PAL systems, the Hilbert transform needed by CMA can be saved for equalizing PAL system video signals. In addition to equalize analog TV signal, this paper can also lead to a joint echo cancellation of analog and digital TV signals transmitted in cable network.     

Digital Separation and Reconstruction of NTSC Signals

A new digital method for separation and reconstruction of NTSC color TV signals is described. Digital conversion between an NTSC signal and its baseband component signals is performed at a sampling rate of(12/5)f_{sc} simeq 8.59MHz (fsc: the color subcarrier frequency), which is lower than the conventionally used3f_{sc}or4f_{sc}sampling rate. Since this lowered sampling rate satisfies the Nyquist condition for NTSC signals, the proposed digital method can provide an effective technique for the component coding of NTSC signals. Simulation results have shown that, with this method, no visible picture quality degradations can be observed for either the color bar signal or SMPTE Pictures.     

基于DDS的电路板检测仪信号源设计

针对某型导弹测试设备电路板检测仪激励信号源具体要求,采用了基于直接数字频率合成技术（DDS）的信号发生器设计方法,介绍了DDS的工作原理,详细阐述了基于FPGA设计DDS信号发生器的主要环节和实现的方法。采用了硬件描述语言Verilog HDL,完成了信号发生器的电路设计和功能仿真,并通过DE2—70开发板结合嵌入式逻辑分析仪Signal—Tap Ⅱ进行了分析验证。实验结果表明,该信号发生器能较好地产生所需激励信号,具有较高的实用价值。     

基于PC的动态电视信号发生器

在计算机上用VisualC ++6 .0语言设计了一系列静态和动态电视信号 ,通过并接在计算机上的VGA到TV信号的转换器 ,输出标准的PAL制或NTSC电视信号。可用作电视信号发生器 ,除了可提供常规的静态电视测试信号外 ,还可提供CIF和QCIF标准序列图像作为动态电视信号 ,弥补传统电视信号发生器在这方面的不足