US 4,027,332 A · Apparatus for monitoring television receivers

Abstract

Apparatus for monitoring the use of television receivers to obtain information for the rating of television programs. The apparatus makes a comparison between the intercarrier frequency signal (i.e., phase) produced by extracting from an operating television receiver tuned to a channel the visual and aural IF frequencies and the respective intercarrier frequency signals (i.e., phase) produced by successively extracting from transmitting sources of television channels the visual and aural IF frequencies. The intermediate frequency signals of the television receiver are sampled and converted into an intercarrier frequency signal. A voltage controlled tuner is tuned to the radio frequency carriers of the various television channels in a hunting sequence. The output signals of the voltage controlled tuner are intermediate frequency signals, which are converted into intercarrier signals. When the intercarrier frequency emanating from the voltage controlled tuner is phase coherent with the intercarrier frequency signal emanating from the operating television receiver over a prescribed period of time, such as 10 seconds, then an identification is made of the channel to which the operating television receiver is tuned and this information is recorded.

Claims20

Dependent claims

Apparatus for monitoring a television receiver comprising:

(a) first means responsive to aural and visual intermediate frequency signals from a television receiver being tuned to a broadcasting channel for producing a first intercarrier signal;
(b) second means tunable to a broadcasting channel and responsive to aural and visual intermediate frequency signals from a television broadcasting signal source for producing a second intercarrier signal in response to being tuned to a broadcasting channel;
(c) third means connected to said second means for causing said second means to be tuned sequentially to a plurality of television broadcast channels;
and
(d) fourth means including a phase detector comparator circuit responsive to said first intercarrier signal and said second intercarrier signal, said fourth means applying a first output voltage to said third means in response to said first and second intercarrier signal being incoherent for causing said second means to be tuned to another broadcasting channel, said fourth means producing a second output voltage in response to said first and second intercarrier signals being coherent to represent said first and second means being tuned to the same broadcasting channel.

2 more elements

Apparatus for monitoring a television receiver comprising:

(a) first means responsive to intermediate frequency signals from a television receiver being tuned to a broadcasting channel for producing a first intercarrier signal;
(b) second means tunable to a broadcasting channel and responsive to intermediate frequency signals from a television broadcasting signal source for producing a second intercarrier signal in response to being tuned to a broadcasting channel;
(c) third means connected to said second means for causing said second means to be tuned sequentially to a plurality of television broadcast channels;
(d) fourth means including a phase detector comparator circuit responsive to said first intercarrier signal and said second intercarrier signal, said fourth means applying a first output voltage to said third means in response to said first and second intercarrier signal being incoherent for causing said second means to be tuned to another broadcasting channel, said fourth means producing a second output voltage in response to said first and second intercarrier frequencies being coherent to represent said first and second means being tuned to the same broadcasting channel;
(e) a data receiver connected to said fourth means for recording data in response to said fourth means producing either said first or said second output voltage;
and
(f) a power line interconnecting said data receiver to said fourth means.

4 more elements

Dependencies are inferred from the claim text.

Apparatus for monitoring television receivers

Life of this patent

Apparatus for monitoring television receivers

Life of this patent

Abstract

Claims20