Back to results
US 5,510,859 AGranted
Tuned signal detector for use with a radio frequency receiver
AssigneeInformation Resources, Inc.
InventorsRalph G. Douglass, Arthur R. Furman
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeInformation Resources, Inc.
InventorsRalph G. Douglass, Arthur R. Furman
Estimating the term…
Disclosed is a tuned channel detector which includes a cable path between a radio frequency source and a receiver such as a TV, wherein the radio frequency source passes first through an attenuator and second through a signal selection module comprising two opposing directional couplers and a single-pole/double-throw switch. The channel to which the TV is tuned is determined by measuring the TV's local oscillator signal from the cable which feeds the radio frequency signal to the TV and, additionally or alternatively, by comparing the signal strength of the input and reflected TV carrier signals at and around the channels under test. Signal detection is further enhanced by modulating the signal mixed with the local oscillator with a tone and/or testing only during certain intervals such as the vertical synchronization interval or the power line cycle. A tone detector having a synchronous rectifier is used to detect low level local oscillator signals. Tuned channel detection is further enhanced through the use of artificial intelligence techniques.
A continuous wave detection apparatus for detecting the presence of a low level continuous waveform amplitude within an input signal comprising the low level continuous waveform and an interfering signal, said apparatus comprising:
A tuned signal detection apparatus for use with a television receiver tuned by a local oscillator signal to a tuned one of a plurality of incoming television signals demarcated by vertical synchronization intervals;
A tuned signal detection apparatus for use with a television receiver for tuning to one of a plurality of television signals, the television receiver generating local oscillator signals having a different predetermined frequency for tuning said receiver to each of said plurality of television signals, the local oscillator signals being modulated by a 60 Hertz power line signal, said tuned signal detection apparatus comprising:
A tuned signal detection system for detecting one of a plurality of television signals to which a television tuner is tuned, said plurality of television signals comprising a scrambled television signal, said detection system comprising:
Dependencies are inferred from the claim text.