在如硫化锑、氧化铝等薄膜靶面的摄象管中,信号是由电子束扫描读取的。由于电子束不是无限细,而具有一定的有效半径,因而随图象的分解度增大,其输出的光电流的调制度将越小。这种效应称为阑效应。这样,在监示器重现出来的图象无论是垂直分解度还是水平 In tubes such as antimony sulfide, aluminum oxide and other film targets, the signal is read by electron beam scanning. Since the electron beam is not infinitely thin and has a certain effective radius, the degree of modulation of the photocurrent outputted by the electron beam is smaller as the resolution of the image is increased. This effect is called the stop effect. In this way, the image reproduced on the monitor is either vertically decomposed or level