JPS6429971U - - Google Patents

Description

[Brief explanation of drawings]

FIG. 1 shows a keyed type AG according to an embodiment of the present invention.
The circuit diagram of the C circuit, FIG. 2, is a waveform diagram of the video detection output for explaining the operation of the AGC circuit. Third
The figure is a circuit diagram of a keyed AGC circuit according to a conventional example.
FIG. 4 is a waveform diagram of the video detection output for explaining the operation of the AGC circuit. 20... AGC circuit, 22, 24... Gate signal generation means, 26... First comparison circuit, 28... Second comparison circuit, 30... Third comparison circuit, 32... Selection circuit, S0
...flyback pulse, S1a...first gate signal, S1b...second gate signal, S3...reference voltage, S
4...Video detection output, S4'...Peak detection output, S
4a...video signal part, S4b...front porch part, S4c...horizontal synchronizing signal, S4d...back porch part, S5a...first comparison signal, S5b...second comparison signal, S5c...third comparison signal.

Claims (1)

[Claims for Utility Model Registration] First and second gate signal generation means for respectively generating and outputting first and second gate signals from flyback pulses, an input section to which a reference voltage is applied, and a peak detection output for the video detection output. , and compares the reference voltage applied to both input parts with the peak detection output in response to the first and second gate signals, respectively, and performs a magnitude comparison between the reference voltage applied to both the input parts and the peak detection output, and also performs a magnitude comparison between the reference voltage applied to both input parts and the peak detection output. comprising first and second comparison circuits that output first and second comparison voltages, respectively; and an input section that receives the first and second comparison voltages from both of the comparison circuits, respectively; a third comparison circuit that compares the magnitude of comparison voltages and outputs a third comparison voltage corresponding to the comparison; and an input section to which comparison voltages from the first and second comparison circuits are respectively applied, both input sections a selection circuit that selects one of the comparison voltages in response to the third comparison voltage from the third comparison circuit and outputs the selected comparison voltage as an AGC voltage from the output section, The means is characterized by having a configuration for generating and outputting first and second gate signals having a pulse width shorter than a horizontal retrace period and longer than a horizontal synchronizing signal period, and whose output timings are shifted from each other. Keyed AGC circuit for television receivers.