The coils above and below the tube conreol the vertical positioning of the electron beam; while the side pair of coils control the two sets of coils, the electron beam dcan be caused to appear any place on the face of the CRT.

• 上下的线圈控制电子束的垂直方向；左右的线圈子控制水平方向。把通过这两对线圈的电流方向和强度改变，就可以控制电子束，使它显现在管面上任何位置。亦称扫描线圈。