Video display

DETAILED DESCRIPTION Accordingly, it is an object of the invention to provide a circuit arrangement for the visual representation of a periodic signal in which the frequency of the periodic signal to be represented need not be less than the horizontal frequency of the receiver, and in which the displayed curve has a horizontal time axis.
According to the present invention there is provided a circuit arrangement for visually representing a horizontal frequency coupled input signal upon the picture screen of a video display device, comprising means for generating a vertical frequency sawtooth signal, means for comparing the input signal with the sawtooth signal so as to produce as output a further signal identifying the moments when the input and sawtooth signals are equal, and a video display device coupled to the output of the comparing means in such manner that the brightness of the picture screen of the display device is controlled by the further signal.
Using the invention it is possible to represent horizontal periods of a video signal in a horizontal position upon the picture screen of a normal video display device.
The frequency resolution of the horizontal periods of the video signal corresponds to the horizontal resolution of the picture reproduction tube (ca.
5Mhz).
Consequently it is also possible to render visible the oscillations of colour carrier frequency in a colour video signal.
It is also possible, in addition to level representation, to achieve reproduction with colour tone fidelity of the colour carrier information in the colour video signal.
Furthermore it is also possible to carry out comparative measurements, e.
g.
by the use of superimposed level indication lines.
An embodiment of the invention, illustrating the foregoing and other objects, features and advantages of the invention, will now be described with reference to the accompanying drawings.