动态像散和聚焦校正电路

电视机在制造和维修过程中,都是通过调整装在行输出变压器（FBT）上的聚焦电位器（Focus）来调整显像管的聚焦状态,这时会发现,屏幕中心部分的聚焦调好了,边缘聚焦就不好,反之边缘好时中心部分不好。这是因为显像管电子枪阴极发射的电子束到达屏面的距离不同,如图1a所示,所以,电子束点的大小和形状就不一样。屏的平面度越平,上述现象就越严重。另外,电子束进入偏转线圈形成的磁场中,因本身有一定的束径,造成在偏转场中各部分偏转作用也不相同,故经偏转后将会产生散焦,使光点变粗,此现象称为偏转像差,或称像散。随着显像管…     

一种用于校正品字形偏转散焦的新方法

现已开发了一种用于校正屏周边红、兰散焦的新型电子枪,因其有施加的动态聚焦电压,该电子枪对红、兰电子束有正象散透镜作用。     

采用多片垂直偏转板的扁平CRT的基础研究

一种采用多片垂直偏转板、带有水平方向偏转电极的新型扁平阴极射线管(FCRT)。有关 FCRT的基础部分的概念和实验模型加以了说明。通过实验和计算研究了模型的静电特性。如果在两片连续的垂直偏转板上依次施加适当的聚焦电压和偏转电压,在垂直扫描过程中,垂直方向的束点尺寸未发生变化。如果在水平方向的偏转电极上施加适当的偏转电压,水平方向的束点尺寸减小。电子束偏转的计算结果表明与测试的结果相符。     

椭圆膜孔透镜电子枪中用作动态聚焦和象散控制的四极透镜

引言众所周知,在一列式彩色CRT中使用了自会聚系统,其偏转线圈引起了很大的象散,这种象散大大减弱了屏边缘的分辨率。近来,做了一些尝试以校正这种象散,即在电子枪中使用一种具有双电位主透镜系统的聚焦电极的四极透镜。在四极透镜上加上一个与束偏转同步的动态电压,以补偿由于偏转系统引起的象散。这种动态电压也可以在整个屏上使电子束聚焦,即能够实现动态聚焦。     

41cm细管颈CDT用电子枪

我们开发出了低功耗的４１ｃｍ细管颈ＣＤＴ用电子枪为了消除管颈趋小所产生的问题，这种电子枪应用了２项关键技术。一是采用单一电压、能够动态校正象散的ＤＡＱ系统，校正了通过水平、垂直偏转磁场的电子束的失真。二是主透镜采用扩展电场式透镜，克服了由于细管颈化的机械的制约，从而实现了主透的大口径比，采用这两项技术，实现了与心前的φ２９．１小管颈用电子枪同等或更好的聚焦特性。     

动态聚焦技术及动态聚焦电子枪

截至目前，动态聚焦技术是改进大屏幕、大偏转角显像管边角分辨率和高清晰度彩色显示管分辨率均匀性的最有效方法。本文介绍与讨论了在荧光屏边缘处电子束点畸变原因以及几种典型动态聚焦电子枪的结构与性能。     

关于动态聚焦的探讨

本文介绍了用动态聚焦电压提高电子束聚焦性能的原理。对采用行逆程脉冲电压经低通滤波器取得动态聚焦电压的方案作了较详细的分析。     

具有MALS功能的新型电子枪

一个新型具有多像散透镜系统的电子枪已开发成功,它有效地改进了全屏分辨率的均匀性。该电子枪的特点是有三个像散射镜（Ｇ１、Ｇ２、主透镜）和两个动态像散透镜（Ｇ３和Ｇ５）。在屏的四角,静态像散透镜消除了偏转散焦。在屏中央,动态像散透镜消除了静态像散射镜的影响。结果使电子束尺寸的垂直和水平之比由原来的１：２,改进成１：１．３,使四角电子束尺寸在水平方向的改进达２５％。     

提高9″显象管边缘分辨率的实验研究

本文从分析9″显象管电子枪的结构特点出发,讨论了影响荧光屏上电子束光点尺寸的三个主要因素:透镜放大率、球面象差和空间电荷效应。提出了用减小调制极孔径,增大调制极与加速极之间的距离等方法来减小电子束最小交叉截面的尺寸和电子束的发散张角;并且以调整电子枪在显象管内的位置,即增大它与偏转线圈之间的相对距离,来减小偏转线圈杂散磁场所引起的偏转散焦;从而有效地改善了整管的聚焦性能,并明显地提高了边缘部分的分辨率。 试验结果和批量生产的管子测试表明:上述方法是卓有成效的,其边缘分辨率能提高50线以上。     

电子束扫描式扁平显像管传输系统的电子光学分析

电子束扫描式扁平显像管中，电子束基本要偏转数次后上屏。本文用曲光轴聚焦理论分析了扁平显像管的偏转系统，包括正交场偏转扫描和电极推动方式。文中给出了电子运动所在的电场分布的级数表达式。由变分方程出发，给出了偏转时曲光轴坐标中的高斯轨迹方程，并对方案进行了计算机模拟，分析了各种因素对于偏转电子束的影响。     

A high-resolution electron gun for thermoplastic recording using prefocus deflection

A demagnification gun of high resolution was developed for thermoplastic recording by deflecting the electron beam at the entry of a large focusing lens. The unconventional approach of prefocus deflection allows close spacing between the "short" focusing lens and the target (phosphor screen or thermoplastic tape) required for demagnification and results in a gun with a relatively short length. The diameter of the focusing lens is about three times larger than the 25-mm diameter area to be scanned in order to keep spot distortions of the deflected beam at a minimum. Electrostatic focusing combined with magnetic deflection was selected. The special focusing lens that is used is shaped for low aberrations, increased demagnification and increased deflection sensitivity. Small deflection fields are required since the electron beam is being deflected in the accelerating field while the electron velocities are still low. The gun operates at 10 kv and delivers a 5-micron spot at 1µa. This corresponds to a resolution of 5000 spot diameters at average current densities in excess of 5 amp/cm². In spite of the high resolution, the over-all length of the gun measured from the target is only 9 inches.     

电子束扫描式扁平显像管偏转系统的电子光学分析

电子束扫描式扁平显像管中，电子束基本要偏转数次后上屏．本文用曲光轴聚焦理论分析了扁平显像管的偏转系统，包括正交场偏转扫描和电极推动扫描方式．文中给出了电子运动所在的电场分布的级数表达式．由变分方程出发，给出了偏转时曲光轴坐标中的高斯轨迹方程，并对方案进行了计算机模拟，分析了各种因素对于偏转电子束的影响．     

About scan magnification of TV picture tubes

In a television receiver the horizontal deflection is of critical importance because of the high deflection power. Recently various proposals have been published, according to which the electron beam is to be deflected over a small angle only, in order to diminish the deflection power. Subsequently this small deflection angle is to be increased by an electrostatic or magnetic lens. In the present paper, it is shown with the aid of general laws of electron optics that such a scan magnification by an electrostatic or magnetic lens necessarily causes a decrease of the resolution, and thereby, of the quality of the television picture, unless known possibilities of increasing the resolution are employed simultaneously. The calculation also affirms that with magnetic deflection, unlike electrostatic deflection, post-acceleration does not lead to a significant reduction in deflection power with unchanged resolution.     

HB2电子枪中空间电荷效应的研究

以阴极射线管(CRT)为例,研究了在不同发射电流下空间电荷效应对荧光屏上电子束点大小的影响。研究结果显示,当阴极电流大于1mA时,空间电荷效应开始起显著作用,而当阴极电流小于1mA时,空间电荷效应的影响逐渐减小,以致可以不考虑。此外,除了空间电荷效应最严重的阴极区外,主透镜区和漂移区的空间电荷效应相对预聚焦区较为显著。     

激光光压偏转原子束分离锂同位素

用激光光压偏转原子束进行了锂同位素分离实验。准直比为450:1的原子束装置,炉温600℃时发生的原子束的数密度为10~9个原子/厘米~3,可调谐连续染料激光经柱面镜系统扩束后与原子束正交。激光线宽6兆赫,在1厘米长的交叉区域内功率密度为70毫瓦/厘米~2。当激光频率对准~7Li2~2P_(3/2)F=3←2~2S_(1/2)F=2跃迁时,~7Li原子从束中偏转。被偏转的原子中几乎不合~6Li,为非常纯的~7Li。当激光频率对准~6Li和~7Li2~2P←2~2S跃迁的其它超精细跃迁时,未看到明显的偏转,这是由于基态超精细能级的光泵浦效应所致。     

Computer calculation of deflection aberrations in electron beams

The aberrations of a magnetically deflected electron beam are investigated in detail using an IBM 7094 computer. The computer programming is applicable to the case of one-dimensional deflection through small angles. The beam is treated as a group of electrons having no internal interactions, no energy spread, and producing no external fields. The field distributions that would produce minimum total aberration for a range of specified working distances, maximum deflection distances, coil widths, and coil openings are calculated. The aberrations produced by these ideal fields and by fields that deviate from the model are predicted. Typically, for a working distance of 3 in (7.62 cm), field coverage of 11 mm, and beam convergence angle of 3.54 × 10^-3rad, the maximum increase in spot diameter is of the order of 0.05 micron. Theoretical limitations on the minimum aberration of a specific deflection system are established. The aberration is expected to be further minimized if dynamic astigmatic correction, as described in this paper, is applied.