US 4,053,203 A · Automatic centering

Abstract

Automatic centering apparatus for use in a television camera having first and second video pickup devices for registering the video signals produced thereby. A first delay circuit responds to the first video signal to provide a first delayed signal, and a second delay circuit responds to the second video signal to provide a second delayed signal. The second delay circuit provides a time delay substantially equal to twice the delay provided by the first delay circuit. If the undelayed first and second video signals are registered properly, the delayed and undelayed second video signals are misregistered by equal yet opposite amounts from the first delayed signal. Relative misregistration of the two signals is detected by subtracting the delayed first video signal from the delayed and undelayed second video signals, and then clipping, integrating and comparing the two difference signals. Two comparator outputs indicate respectively when the first clipped and integrated signal is higher than the second, and when the second clipped and integrated signal is higher than the first. These two comparator outputs control the changes in amplitude of an analog output signal which serves as the registration correction signal for one of the two video pickup devices.

Claims17

Dependent claims

Automatic centering apparatus for use with a video camera having means for providing at least first and second video signals and means responsive to a registration control signal for adjusting the registration of said signals, said centering apparatus comprising:

first delay means responsive to said first video signal for delaying said signal by a first amount to provide a first delayed signal;
second delay means responsive to said second video signal for delaying said signal by a second amount substantially twice the length of said first amount to provide a second delayed signal;
detector means comprising signal subtractor means for differentially combining said second video signal and said first delayed signal to provide a first difference signal and similarly combining said second delayed signals and said first delayed signal to provide a second difference signal, signal clipper means responsive to said first and second difference signals for selectively limiting the amplitudes thereof to respectively provide first and second clipped signals, and integrator means responsive to said first and second clipped signals for respectively integrating the amplitudes thereof to provide first and second detector output signals;
and,
means responsive to said first and second detector output signals for providing said registration control signal and for changing said registration control signal in response to the difference between said detector output signals.

2 more elements

first delay means responsive to said first video signal for delaying said signal by a first amount to provide a first delayed signal;
second delay means responsive to said second video signal for delaying said signal by a second amount substantially twice the length of said first amount to provide a second delayed signal;
detector means responsive to said first delayed signal and said second video signal to provide a first detector output signal indicative of the misregistration therebetween and further responsive to said first delayed signal and said second delayed signal to provide a second detector output signal indicative of the misregistration therebetween;
means responsive to said first and second detector output signals for providing said registration control signal and for changing said registration control signal in response to the difference between said detector output signal;
gating means interposed between said signal detector means on the one hand and said second video signal and said second delayed signal on the other hand, said gating means having a single output connected to said detector means for sequentially gating said second video signal and then said second delayed signal to said signal detector means along said single output in accordance with the state of a periodic gating signal;
and,
delay control means for providing said gating signal.

4 more elements

Dependencies are inferred from the claim text.

Automatic centering

Life of this patent

Automatic centering

Life of this patent

Abstract

Claims17