Video signal reproducing device with electron beam scanning velocity

Abstract

In a video signal reproducing device having a cathode ray tube in which at least one electron beam is focused at a phosphor screen and is made to scan the screen in line-scanning and vertical directions, and in which the beam focusing is effected by an electron lens constituted by at least two tubular electrodes arranged coaxially in succession along the axis of the tube with a relatively low potential being applied to one of the electrodes and a relatively high potential being applied to the other electrode or electrodes; electron beam scanning velocity modulation is effected by forming the tubular electrode to which the low potential is applied in two parts which are axially separated along a vertical plane inclined relative to the tube axis, and by applying across the two parts of such tubular electrode a control signal which is produced in response to transient changes in the luminance or brightness of the video signal being reproduced. Such control signal is preferably provided by a circuit which employs only a single delay line to provide the velocity modulating control signal as the difference between a luminance or brightness component of the video signal and such component delayed twice by the delay line, and a further control signal constituted by the luminance or brightness component delayed once by the delay line and which is employed for modulating the intensity of the electron beam or beams.