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三、彩色电视信号(一)频谱交错法及副载频的选择为了满足兼容的要求,在彩色电视信号中必须包含一个代表图象亮度的亮度信号 E_Y,并且要使黑白电视机接收到的黑白图象具有良好的质量。E_Y 信号的传送方式和频带宽度与黑白电视传送时一样,那么代表图象颜色的两个色差信号究竟如何传送呢?理论和实践都证明,亮度信号并没有全部占满整个频带,它是由行频谐波为中心的一束束离散的谱线(主谱线)组成,并以行频为间距排列的。离主谱频越远,主谱线幅度越小,在主谱线旁边又存在着以场频
Third, the color TV signals (A) the choice of frequency spectrum and subcarrier frequency In order to meet the compatibility requirements, the color television signal must contain a brightness signal representative of the brightness of the image E_Y, and to make black and white TV receiver to receive the black and white The image is of good quality. E_Y signal transmission and frequency bandwidth and black and white television transmission the same, then the representative of the image color of the two color difference signal transmission? Theory and practice have proved that the brightness signal does not fully fill the entire frequency band, which is by the line Frequency harmonics as the center of a bundle of discrete lines (main line) composition, and the frequency of the array for the pitch. The farther away from the main spectrum, the smaller the main spectral line, there is a field frequency next to the main spectral line