引言在彩色显示器件中,一字型自会聚彩色显象管以价格低廉、会聚性能可靠而最为普遍。然而,这种类型的彩色显象管所用的偏转线圈使电子束产生象散,导致偏转时分辨率大为降低。在显示数据—图形的情况下,满屏都有高分辨率是极为重要的,因而偏转象散散焦就成了严重的问题。也曾有人提出几种方案解决此问题。近几年来为了 INTRODUCTION In color display devices, in-line self-converging color picture tubes are most commonly used at low cost and with reliable convergence. However, the deflection yoke used for this type of color picture tube causes astigmatism in the electron beam, resulting in a much lower resolution when deflected. In the case of data-graphics, it is of paramount importance that the full screen has high resolution, and deflecting astigmatism becomes a serious problem. Some people have also proposed several solutions to this problem. In recent years in order