Deflection system for TV obviating blanking beam - sweeps beam across perfectly horizontally and returns at same speed but displaced by one line

摘要

The t.v. line deflection system generates a horizontal deflection field that deflects the electron beam exactly horizontally. The electron beam returns to the point of departure when it reaches the end of a line after being displaced by the width of one line. The speed at which it returns is equal to the speed of its sweep. There is no beam blanking, i.e. both sweep and return excite a line of picture points. The change-over in the horizontal deflection field is accomplished using a bridge circuit in whose diagonal the horizontal coil is located. The bridge contains electronic switches opened and closed alternately at a rate equal to the line frequency.