Circuit for the continuous zoom adjustment of the picture width in a television receiver

摘要

In a television receiver, having the ability to display differing image formats, the image width is capable of being continuously adjustable in the manner of a zoom effect. The ability to continuously adjust the image width is accomplished without any perceptible effect on the horizontal scan output. In that circuit, a tangent capacitor is coupled to a second capacitor with a switch being connected for switching the second capacitor into and out of the circuit. The switch is closed for an adjustable period beginning at the line center.