Monitoring system for TV, cable and VCR

• US 5,495,282 A
• Filed: 11/03/1992
• Issued: 02/27/1996
• Est. Priority Date: 11/03/1992
• Status: Expired due to Fees

• Current Assignee: Arbitron Inc. (MOOD Media Corporation)
• Original Assignee: Arbitron Inc. (MOOD Media Corporation)
• Inventors: Mostafa, Ayman A., Lynch, Wendell D., Jensen, James M.
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): VO, NGUYEN THANH
• Application Number:
  US07/970,633
• Time in Patent Office: 1,211 Days
• Field of Search: 455/2, 455/67.1, 455/67.4, 455/6.2, 455/3.1, 455/6.2, 455/6.1, 348/1, 348/2, 348/4, 348/5, 348/10, 348/6, 358/84, 358/335, 358/189, 358/191.1, 358/192.1, 358/193.1
• US Class Current: 725/21
• CPC Class Codes: H04H 60/43 for identifying broadcast channels
• CPC Class Codes: H04N 5/765 Interface circuits between an apparatus for recording and another apparatus
• CPC Class Codes: H04N 5/782 on tape

Abstract

In a system for monitoring use of a video monitoring system, RF signals are injected into a cable converter and a VCR in order to detect channels selected by the cable converter and VCR. Installation of probes is not required for channel detection. Channel identification signals are also injected into the VCR and cable converter for recording by the VCR on videotape. Respective channel identification signals are provided to the cable converter and VCR with time multiplexing. The state of the "TV/VCR" switch of the VCR is determined by injecting a code signal into the VCR and determining whether that signal is present in an RF video signal output by the VCR. The system includes a switch for interconnecting the cable converter, VCR and TV and also for coupling injection signals to respective inputs of the cable converter and VCR. The system also includes an injection signal receiver that detects signals injected into and passed through the VCR and cable converter for the purpose of channel detection. The receiver also receives data contained in channel identification signals. The receiver is selectively connectable to the VCR and the cable converter. Changes in the signal source for the cable converter and VCR are optionally detected by sampling and holding signal levels during certain horizontal blanking intervals of the signal output from the cable converter or VCR. Monitoring of a system that includes two VCRs is also disclosed.

Claims

1. A method of monitoring the usage of a video monitoring system that includes a video monitoring device, a cable converter and a VCR, said cable converter having an output terminal that is selectively connected to an input terminal of said VCR, the method comprising the steps of:

determining by means of a monitoring device whether said output terminal of said cable converter is connected to said input terminal of said VCR;

if it is determined that said output terminal of said cable converter is connected to said input terminal of said VCR, supplying a first channel detection signal from said monitoring device to an input terminal of said cable converter while varying a frequency of said first channel detection signal, receiving by means of said monitoring device a signal output from an output terminal of said VCR, determining by means of said monitoring device whether said first channel detection signal supplied to said input terminal of said cable converter is present in said signal output from said output terminal of said VCR, and if so, detecting by means of said monitoring device which of a first plurality of channels has been selected by said cable converter on the basis of the frequency of said first channel detection signal that is present in said signal output from said output terminal of said VCR; and

if it is determined that said output terminal of said cable converter is not connected to said input terminal of said VCR, supplying a second channel detection signal from said monitoring device to said input terminal of said VCR while varying a frequency of said second channel detection signal, receiving by means of said monitoring device a signal output from said VCR, determining by means of said monitoring device whether said second channel detection signal is present in said signal output from said VCR, and if so, detecting by means of said monitoring deyice which of a second plurality of channels has been selected for reception by said VCR on the basis of the frequency of said second channel detection signal that is present in said signal output from said VCR.

2. The method of claim 1, wherein said video monitoring system includes a second VCR and further comprising the steps of:

supplying a third channel detection signal from said monitoring device to an input of said second VCR; and

determining by means of said monitoring device whether said third channel detection signal is present in a signal output from said second VCR, and if so, detecting which of a third plurality of channels has been selected for reception by said second VCR on the basis of the frequency of said third channel detection signal that is present in said signal output from said second VCR.

3. The method of claim 1, further comprising the step of supplying a channel identification signal to said input terminal of said VCR when said output terminal of said cable converter is not connected to said input terminal of said VCR, said channel identification signal including data that identifies a channel selected for reception by said VCR and being recorded on a magnetic tape by said VCR to identify a source of a program signal recorded on said magnetic tape with said channel identification signal.

4. The method of claim 3, wherein said input terminal of said VCR is an RF input terminal.

5. The method of claim 1, further comprising the step of supplying a channel identification signal to said input terminal of said cable converter at a time when said output terminal of said cable converter is connected to said input terminal of said VCR;

said channel identification signal including data that identifies a channel selected by said cable converter and being recorded on a magnetic tape by said VCR to identify a source of a program signal recorded on said magnetic tape with said channel identification signal.

6. The method of claim 5, further comprising the step of supplying a second channel identification signal to said input terminal of said VCR at a time when said output terminal of said cable converter is not connected to said input terminal of said VCR;

said second channel identification signal including data that identifies a channel selected for reception by said VCR and being recorded on a further magnetic tape by said VCR to identify a source of a second program signal recorded on said further magnetic tape with said second channel identification signal.

7. An apparatus for monitoring the usage of a video monitoring system that includes a video monitoring device, a cable converter and a VCR, the apparatus comprising:

means for selectively connecting an output terminal of said cable converter to an input terminal of said VCR;

means for supplying a first channel detection signal to an input terminal of said cable converter while varying a frequency of said first channel detection signal when said output terminal of said cable converted is connected to said input terminal of said VCR;

means for receiving a signal output from an output terminal of said VCR;

means connected to said means for receiving for detecting that said first channel detection signal is present in said signal output from said output terminal of said VCR and for determining which of a plurality of channels has been selected by said cable converter on the basis of the frequency of said first channel detection signal that was detected in said signal output from said output terminal of said VCR;

means for supplying a second channel detection signal to said input terminal of said VCR while varying a frequency of said second channel detection signal when said output terminal of said cable converter is not connected to said input terminal of said VCR; and

means connected to said means for receiving for detecting that said second channel detection signal is present in said signal output from said output terminal of said VCR and for determining which of a second plurality of channels has been selected for reception by said VCR on the basis of the frequency of said second channel detection signal that was detected in said signal output from said output terminal of said VCR.

8. The apparatus of claim 7, wherein said means for supplying said first channel detection signal and said means for supplying said second channel detection signal comprise a single RF generator means for generating both said first and second channel detection signals.

9. The apparatus of claim 7, further comprising means for supplying a channel identification signal to said input terminal of said VCR when said output terminal of said cable converter is not connected to said input terminal of said VCR, said channel identification signal including data that identifies a channel selected for reception by said VCR and being recorded on a magnetic tape by said VCR to identify a source of a program signal recorded on said magnetic tape with said channel identification signal.

10. The apparatus of claim 7, further comprising means for supplying a channel identification signal to said input terminal of said cable converter when said output terminal of said cable converter is connected to said input terminal of said VCR, said channel identification signal including data that identifies a channel selected by said cable converter and being recorded on a magnetic tape by said VCR to identify a source of a program signal recorded on said magnetic tape with said channel identification signal.

11. The apparatus of claim 10, further comprising means for supplying a second channel identification signal to said input terminal of said VCR when said output terminal of said cable converter is not connected to said input terminal of said VCR, said second channel identification signal including data that identifies a channel selected for reception by said VCR and being recorded on a further magnetic tape by said VCR to identify a source of a second program signal recorded on said further magnetic tape with said second channel identification signal.

12. The apparatus of claim 11, wherein said means for supplying said first channel detection signal and said means for supplying said second channel detection signal comprise a single RF generator means for generating both said first and second channel detection signals.

13. The apparatus of claim 12, further comprising means for generating said channel identification signals by modulating an RF signal generated by said RF generator means.

14. A method of monitoring usage of a video monitoring system that includes a video monitoring device and a VCR, the method comprising the steps of:

supplying a channel detection signal to an input terminal of said VCR;

detecting that said channel detection signal is present in a signal outputted from an output terminal of said VCR and determining to which channel said VCR is tuned; and

supplying a channel identification signal from said monitoring device to an RF input of said VCR, said channel identification signal including data that identifies said detected channel and being recorded on a magnetic tape by said VCR to identify a source of a program signal recorded on said magnetic tape with said channel identification signal.

15. The method of claim 14, further comprising the step of monitoring by means of said monitoring device a signal outputted by the VCR to determine whether said channel identification signal is present in said signal output by the VCR.

16. The method of claim 15, wherein said channel identification signal is repeatedly supplied to said RF input by said monitoring device at regular intervals and further comprising the step of detecting by.means of said monitoring device a change in a source of said signal output by the VCR by determining that said channel identification signal is not present in said signal outputted by the VCR.

17. The method of claim 14, wherein said video monitoring system includes a second VCR and further comprising the steps of:

detecting by means of said monitoring device a channel to which said second VCR is tuned; and

supplying a second channel identification signal from said monitoring device to an RF input of said second VCR, said second channel identification signal including data that identifies said channel to which said second VCR is tuned and being recorded on a further magnetic tape by said second VCR to identify a source of a second program signal recorded on said further magnetic tape with said second channel identification signal.

18. The method of claim 17, further comprising the step of generating both of said channel identification signals by using a single RF generating means.

19. An apparatus for monitoring usage of a video monitoring system that includes a video monitoring device and a VCR, the apparatus comprising:

means for supplying a channel detection signal to an input terminal of said VCR;

means for detecting that said channel detection signal is present in a signal outputted from an output terminal of said VCR and for determining to which channel said VCR is tuned; and

signal supply means for supplying a channel identification signal to an RF input of said VCR, said channel identification signal including data that identifies said detected channel and being recorded on a magnetic tape by said VCR to identify a source of a program signal recorded on said magnetic tape with said channel identification signal.

20. The apparatus of claim 19, further comprising means for monitoring said signal outputted by the VCR to determine whether said channel identification signal is present in said signal output by the VCR.

21. The apparatus of claim 20, wherein said signal supply means comprises means for repeatedly supplying said channel identification signal to said RF input at regular intervals and further comprising means for detecting a change in a source of said signal outputted by the VCR by determining that said channel identification signal is not present in said signal outputted by the VCR.

22. The apparatus of claim 19, wherein said video monitoring system includes a second VCR and further comprising:

means for detecting a channel to which said second VCR is tuned; and

means for supplying a second channel identification signal to an RF input of said second VCR, said second channel identification signal including data that identifies said channel to which said second VCR is tuned and being recorded on a further magnetic tape by said second VCR to identify a source of a second program signal recorded on said further magnetic tape with said second channel identification signal.

23. The apparatus of claim 22, further comprising a single RF generating means for generating both of said channel identification signals.

24. A method of monitoring usage of a video recording device that is tuned to a channel in order to receive a program signal, said video recording device being selectively operated in a recording mode in which said program signal is recorded on a recording medium, the method comprising the steps of:

detecting by means of a monitoring device said channel to which said video recording device is tuned;

detecting by means of said monitoring device timing pulses present in said program signal;

generating by means of said monitoring device an identification signal that identifies said detected channel;

modulating by means of said monitoring device an RF carrier with the generated identification signal, the RF carrier having a frequency which corresponds to the frequency of said detected channel;

determining by means of said monitoring device whether said video recording device is being operated in the recording mode; and

when it is determined that said video recording device is not being operated in the recording mode, repeatedly supplying said modulated RF carrier from said monitoring device to an RF input of said video recording device on the basis of said detected timing pulses and in synchronism with a first set of scanning intervals of said program signal, and when it is determined that said video recording device is being operated in the recording mode, repeatedly supplying said modulated RF carrier from said monitoring device to the RF input of said video recording device on the basis of said detected timing signals and in synchronism with a second set of scanning intervals of said program signal so that said identification signal is recorded on said recording medium in said second set of scanning intervals of said program signal to identify a source of said program signal;

said second set of intervals comprising said first set and additional scanning intervals of said program signal.

25. The method of claim 24, wherein said video recording device is selectively operated in a playback mode in which said program signal and said identification signal recorded on said recording medium are played back and further comprising the step of determining by means of said monitoring device whether or not said video recording device is being operated in the playback mode.

26. The method of claim 25, wherein said step of determining whether or not the video recording device is being operated in the playback mode comprises the substeps of:

sequentially supplying a plurality of channel detecting signals to the RF input of the video recording device;

monitoring signals output from the video recording device; and

determining that the video recording device is being operated in the playback mode if none of said plurality of detecting signals are present in said signals output by the video recording device.

27. The method of claim 25, wherein said identification signal includes data representative of a time at which said identification signal was generated and further comprising the steps of detecting and decoding an identification signal that has been recorded on said recording medium when the video recording device is playing back a program signal recorded therewith in order to determine a time at which and a channel from which said program signal was recorded.

28. The method of claim 24, wherein said step of determining whether or not the video recording device is being operated in the recording mode comprises detecting a level of power drawn by the video recording device.

29. The method of claim 24, wherein said step of determining whether or not the video recording device is being operated in the recording mode comprises detecting an erase signal that is applied to the recording medium by the video recording device when the video recording device is being operated in the recording mode.

30. The method of claim 24, wherein said step of supplying said modulated RF carrier to the RF input of the video recording device comprises interrupting said program signal during intervals that are in synchronism with times at which said modulated RF carrier is supplied so that said video recording device receives only said modulated RF carrier during said intervals.

31. An apparatus for monitoring usage of a video recording device that is tuned to a channel in order to receive a program signal, said device being selectively operated in a recording mode in which said program signal is recorded on a recording medium, the apparatus comprising:

means for detecting said channel to which said device is tuned, the channel detecting means being coupled to an output terminal of said device;

means for detecting timing pulses present in said program signal, the timing pulse detecting means being coupled to said output terminal of said device;

means for generating an identification signal that identifies said detected channel;

means for modulating an RF carrier with the generated identification signal, the RF carrier having a frequency which corresponds to the frequency of said detected channel;

means for determining whether said device is being operated in the recording mode, the recording mode determining means including one of erase sensor pickup means located on or near said VCR for detecting a VCR erase signal and power consumption sensing means coupled to an input power terminal of said VCR for sensing a level of power consumption by said VCR; and

means for supplying said modulated RF carrier to an RF input of the device in accordance with a timing based on said detected timing pulses;

said means for supplying comprising means repeatedly supplying said modulated RF carrier in synchronism with a first set of scanning intervals of said program signal when it is determined that the device is not being operated in the recording mode and repeatedly supplying said modulated RF carrier in synchronism with a second set of scanning intervals of said program signal when it is determined that the device is being operated in the recording mode so that said identification signal is recorded on said recording medium in said second set of scanning intervals of said program signal to identify a source of said program signal;

said second set of intervals comprising said first set and additional scanning intervals of said program signal.

32. The apparatus of claim 31, wherein said device is selectively operated in a playback mode in which said program signal and said identification signal recorded on said recording medium are played back and further comprising means for determining whether or not said device is being operated in the playback mode, the playback mode determining means being coupled to said output terminal of said device.

33. The apparatus of claim 32, wherein said means for determining whether or not the device is being operated in the playback mode comprises:

means for sequentially supplying a plurality of channel detection signals to the RF input of the device;

means for monitoring signals output from the device; and

means for determining that the device is being operated in the playback mode if none of said plurality of detection signals are present in said signals output by the device.

34. The apparatus of claim 31, wherein said means for supplying said modulated RF carrier to the RF input of the device comprises means for interrupting said program signal during intervals that are in synchronism with times at which said modulated RF carrier is supplied so that said device receives only said modulated RF carrier during said intervals.

35. A method of monitoring usage of a video monitoring system that includes a video monitoring device, a cable converter and a VCR, the method comprising the steps of:

detecting by means of a monitoring device which of a plurality of channels is selected for reception by said cable converter;

connecting an output terminal of said cable converter to an input terminal of said VCR; and

supplying a channel identification signal from said monitoring device to an input terminal of said cable converter, said channel identification signal including data that identifies said detected channel and being recorded on a magnetic tape by said VCR to identify a source of a program signal recorded on said magnetic tape with said channel identification signal.

36. The method of claim 35, wherein said channel identification signal is repeatedly supplied to said input of the cable converter at regular intervals and further comprising the steps of:

monitoring by means of said monitoring device a signal output by the cable converter to determine whether said channel identification signal is present in said signal outputted by the cable converter; and

detecting by means of said monitoring device a change of channels by the cable converter by determining that said channel identification signal is not present in said signal output by the cable converter.

37. The method of claim 35, wherein said channel detecting step comprises the substeps of:

supplying a channel detection signal to said input terminal of said cable converter while varying a frequency of said channel detection signal;

receiving signals output from an output terminal of said VCR;

detecting that said channel detection signal is present in said signals output from said output terminal of said VCR; and

determining which of said plurality of channels is selected by said cable converter on the basis of the frequency of said channel detection signal that was detected in said signal output from said output terminal of said VCR.

38. An apparatus for monitoring usage of a video monitoring system that includes a video monitoring device, a cable converter and a VCR, the apparatus comprising:

channel detection means for detecting which of a plurality of channels is selected for reception by said cable converter, said channel detection means being included in said monitoring device and being coupled to at least one of an input terminal and an output terminal of said cable converter;

means for connecting said output terminal of said cable converter to an input terminal of said VCR; and

means for supplying a channel identification signal to an input terminal of said cable converter, said channel identification signal including data that identifies said detected channel and being recorded on a magnetic tape by said VCR to identify a source of a program signal recorded on said magnetic tape with said channel identification signal, the supplying means being included in said monitoring device.

39. The apparatus of claim 38, wherein said means for supplying said channel identification signal comprises means for repeatedly supplying said identification signal to said input of the cable converter at regular intervals and further comprising:

means for monitoring a signal output by the cable converter to determine whether said channel identification signal is present in said signal output by the cable converter, the monitoring means being included in said monitoring device; and

means for detecting a change of channels by the cable converter by determining that said channel identification signal is not present in said signal output by the cable converter, the channel change detecting means being included in said monitoring device.

40. The apparatus of claim 38, wherein said channel detection means comprises:

means for supplying a channel detection signal to said input of said cable converter while varying a frequency of said channel detection signal;

means for receiving signals output from an output terminal of said VCR;

means for detecting that said channel detection signal is present in said signals output from said output terminal of said VCR; and

means for determining which of said plurality of channels is selected by said cable converter on the basis of the frequency of said channel detection signal that was detected in said signal output from said output terminal of said VCR.

41. In a video monitoring system including a VCR which has an input terminal for receiving input video signals and an RF output terminal for outputting RF modulated video signals, the VCR being selectively operated in a first mode in which said input video signals are passed through to said RF output terminal without tuning and a second mode in which a tuned RF modulated video signal is output via said RF output terminal, a method of detecting the VCR'"'"'s mode of operation, comprising the steps of:

supplying a code signal from a monitoring device to said input terminal of the VCR;

receiving and tuning a signal output from said RF output terminal by means of said monitoring device in order to provide a tuned video signal for display by a display device;

determining by means of said monitoring device whether said code signal is present in said signal that was received and tuned, and

determining by means of said monitoring device that the VCR is in said first mode if said code signal is present in said signal that was received and tuned, and that the VCR is in said second mode if said code signal is not present in said signal that was received and tuned.

42. The method of claim 41, wherein said receiving and tuning step comprises supplying said signal output from said RF output terminal to a tuning/meter device which tunes said signal output from said RF output terminal, provides said tuned signal to said display device and collects data concerning usage of said display device.

43. An apparatus for detecting a mode of operation of a VCR which has an input terminal for receiving input video signals and an RF output terminal for outputting RF modulated video signals, the VCR being selectively operated in a first mode in which said input video signals are passed through to said RF output terminal without tuning and a second mode in which a tuned RF modulated video signal is output via said RF output terminal, the apparatus comprising:

means for supplying a code signal to said input terminal of the VCR;

means for receiving and tuning a signal output from said RF output terminal in order to .provide a tuned video signal for display by a display device; and

means for determining whether said code signal is present in said signal that was received and tuned, determining that the VCR is in said first mode if said code signal is present in said signal that was received and tunedt and determining that the VCR is in said second mode if said code signal is not present in said signal that was received and tuned.

44. The apparatus of claim 43, wherein said receiving and tuning means comprises a tuning/meter device which tunes said signal output from said RF output terminal, provides said tuned signal to said display device and collects data concerning usage of said display device.

45. A method of monitoring usage of a VCR that is selectively operated in a playback mode in which the VCR reproduces a video signal from a videotape, the method of comprising the steps of:

sequentially supplying a plurality of channel detection signals to an RF input terminal of the VCR;

monitoring signals output from the VCR; and

detecting that the VCR is being operated in the playback mode by determining that none of said channel detection signals are present in said signals output from the VCR.

46. The method of claim 45, further comprising the step of determining whether the VCR is playing back a program recorded on the videotape by the VCR by detecting channel identification signals recorded on the videotape with the program and played back with the program by the VCR, said channel identification signals comprising data that identifies a time at which, a channel from which, and the VCR by which said program was recorded.

47. An apparatus for monitoring usage of a VCR that is selectively operated in a playback mode in which the VCR reproduces a video signal from a videotape, the apparatus comprising:

means for sequentially supplying a plurality of channel detection signals to an RF input terminal of the VCR;

means for monitoring signals output from the VCR; and

means for detecting that the VCR is being operated in the playback mode by determining that none of said channel detection signals are present in said signals output from the VCR.

48. The apparatus of claim 47, further comprising means for determining whether the VCR is playing back a program recorded on the videotape by the VCR by detecting channel identification signals recorded on the videotape with the program and played back with the program by the VCR, said channel identification signals comprising data that identifies a time at which, a channel from which, and the VCR by which said program was recorded.

49. In a device for monitoring usage of a video monitoring system that includes a video monitor, a cable converter and a VCR, an apparatus for interconnecting said video monitor, cable converter and VCR, the apparatus comprising:

a plurality of input terminals for each receiving video signals from respective sources including an output terminal of said cable converter;

a VCR input terminal for receiving signals from an output terminal of said VCR;

a tuning/meter module for receiving an input video signal, tuning said input video signal, providing said tuned signal to an input terminal of said video monitor, and collecting data concerning usage of said video monitor;

a VCR output terminal for providing a selected signal to an input terminal of said VCR;

first switch means for selectively coupling one of said plurality of input terminals to said VCR output terminal;

second switch means for coupling a selected one of said VCR input terminal and said plurality of input terminals to said tuning/meter module; and

control means for controlling operation of said first and second switch means.

50. The apparatus of claim 49, wherein said plurality of input terminals comprises:

an antenna input terminal for receiving broadcast television signals from an antenna;

an auxiliary input terminal for receiving signals from an auxiliary source;

a first cable input terminal for receiving cable television signals from a first cable;

a second cable input terminal for receiving cable television signals from a second cable; and

a cable converter input terminal for receiving signals output by said cable converter.

51. The apparatus of claim 50, further comprising:

an injection signal input terminal for receiving RF injection signals;

two cable converter output terminals;

each coupled to a respective one of said cable input terminals, for providing said cable television signals to said cable converter; and

third switch means controlled by said control means for coupling said injection signal input terminal to a selected one of said two cable converter output terminals and said VCR output terminal.

52. The apparatus of claim 51, further comprising:

means for generating said RF injection signals; and

means for supplying said RF injection signals to said injection signal input terminal.

53. The apparatus of claim 52, wherein said RF injection signals comprise channel identification signals.

54. The apparatus of claim 50, further comprising:

a second VCR input terminal for receiving signals output by a second VCR;

a second VCR output terminal for providing a selected signal to said second VCR; and

third switch means for selectively coupling to said second VCR output terminal a selected one of said input terminals other than said second VCR input terminal;

said second switch means including means for selectively coupling said second VCR input terminal to said tuning/meter module;

said first switch means including means for selectively coupling said second VCR input terminal to said VCR output terminal that is not said second VCR output terminal.

55. The apparatus of claim 54, further comprising:

an injection signal input terminal for receiving RF injection signals;

two cable converter output terminals, each coupled to a respective one of said cable input terminals, for providing said cable television signals to said cable converter; and

fourth switch means controlled by said control means for coupling said injection signal input terminal to a selected one of said second VCR output terminal, said VCR output terminal that is not said second VCR output terminal, and said two cable converter output terminals.

56. An apparatus for receiving channel detection and channel identification signals generated by injection signal generating circuitry and applied to and transmitted through an RF channel selection device, the apparatus comprising:

an input terminal for receiving signals output from said RF channel selection device;

means for selectively coupling said input terminal to one of a plurality of channel selection devices;

means for transmitting a signal indicative of a level of said signals output from said RF channel selection device being below a predetermined level;

means for transmitting to a control means signals indicative of timing pulses present in a video signal output from the channel selection device, said timing pulses being indicative of vertical and horizontal scanning periods of said video signal;

means connected to said input terminal for generating a hit signal in response to said channel detection signal being present at said input terminal and for transmitting said hit signal to said control means; and

means connected to said input terminal for transmitting data contained in said received channel identification signal to said control means.

57. An apparatus for receiving channel detection and channel identification signals generated by injection signal generating circuitry and applied to and transmitted through an RF channel selection device, the apparatus comprising:

an input terminal for receiving signals output from said RF channel selection device;

means connected to said input terminal for generating a hit signal in response to said channel detection signal being present at said input terminal and for transmitting said hit signal to a control means, said hit signal generating means including

means for generating a log power signal that varies as a function of the logarithm of the spectral energy, in a predetermined frequency band, of a signal present at said input terminal;

means for integrating said log power signal;

means for amplifying said integrated log power signal;

means for averaging said amplified signal to produce a reference signal; and

means for comparing said amplified signal to said reference signal and generating said hit signal in response to a level of said amplified signal exceeding a level of said reference signal by a predetermined factor; and

means connected to said input terminal for transmitting data contained in said received channel identification signal to said control means.

58. An apparatus for receiving channel detection and channel identification signals generated by injection signal generating circuitry and applied to and transmitted through an RF channel selection device, the apparatus comprising:

an input terminal for receiving signals output from said RF channel selection device including a video signal having horizontal scanning intervals;

means connected to said input terminal for generating a hit signal in response to said channel detection signal being present at said input terminal and for transmitting said hit signal to a control means; and

means connected to said input terminal for transmitting data contained in said received channel identification signal to said control means and including means responsive to a control signal supplied thereto for preventing said data transmitting means from transmitting data at times other than predetermined ones of said horizontal scanning intervals of said video signal.

59. The apparatus of claim 58, wherein said intervals are concurrent with times at which said channel identification signals are applied to the channel selection device.

60. An apparatus for receiving channel detection and channel identification signals generated by injection signal generating circuitry and applied to and transmitted through an RF channel selection device, the apparatus comprising:

an input terminal for receiving signals output from said RF channel selection device;

means connected to said input terminal for generating a hit signal in response to said channel detection signal being present at said input terminal and for transmitting said hit signal to a control means, said hit signal generating means including

means for generating a ramp signal in response to said channel detection signal being present at said input terminal;

means for differentiating said ramp signal;

means for filtering said differentiated signal;

means for buffering said filtered signal; and

means for comparing said buffered signal against a reference level and generating said hit signal in response to said buffered signal being not less than said reference level; and

means connected to said input terminal for transmitting data contained in said received channel identification signal to said control means.

61. A method of determining whether a channel selection device is receiving an input signal from a predetermined signal source, said method comprising the steps of:

receiving a video baseband signal originating from said channel selection device, said video baseband signal having vertical blanking intervals that each include a plurality of horizontal scanning intervals;

separating vertical and horizontal synchronizing signals from the received video baseband signal;

selecting first, second and third ones of said plurality of horizontal scanning intervals in one of said vertical blanking intervals of said received video baseband signal;

interrupting said input signal during said second and third horizontal scanninq intervals and supplying a comparison signal to said channel selection device during said third horizontal scanning interval;

generating a respective sample level for each of said first, second and third horizontal scanning intervals, by sampling and holding a level of said received video baseband signal during each of said first, second and third horizontal scanning intervals;

storing said generated sample levels;

comparing said stored sample levels; and

determining that said input signal is from said predetermined signal source if said stored sample level corresponding to said third horizontal scanning interval is closer to said stored sample level corresponding to said first horizontal scanning interval than to said stored sample level corresponding to said second horizontal scanning interval.

62. The method of claim 61, wherein said input signal is an RF video signal and said predetermined signal source is a predetermined channel, and said comparison signal is an RF video signal at a frequency that corresponds to said predetermined channel.

63. A method of determining whether a channel selection device is receiving an input signal from a cable over which a plurality of programs are transmitted simultaneously on respective channels, said cable being selectively connected to said channel selection device, said method comprising the steps of:

receiving a video baseband signal originating from said channel selection device, said video baseband signal having vertical blanking intervals that each include a plurality of horizontal scanning intervals;

separating vertical and horizontal synchronizing signals from the received video baseband signal;

selecting first and second ones of said plurality of horizontal scanning intervals

disconnecting said cable from said channel selection device during said second horizontal scanning interval;

generating a respective sample level for each of said first and second horizontal scanning intervals, by sampling and holding a level of said received video baseband signal during each of said first and second horizontal scanning intervals;

storing said qenerated sample levels;

comparing said stored sample levels; and

determining that said channel selection device is not receiving the input signal from said cable if said stored sample levels corresponding to said first and second horizontal scanning intervals differ by less than a predetermined amount.

64. The method of claim 63, wherein said channel selection device is a cable converter.

65. Apparatus for determining whether a channel selection device is receiving an input signal from a predetermined signal source, said apparatus comprising:

means for receiving a video baseband signal originating from said channel selection device, said video baseband signal having vertical blanking intervals that each include a plurality of horizontal scanning intervals;

means for separating vertical and horizontal synchronizing signals from the received video baseband signal;

selecting means for selecting first, second and third ones of said plurality of horizontal scanning intervals in one of said vertical blanking intervals of said received video baseband signal;

means for interrupting said input signal during said second and third horizontal scanning intervals and supplying a comparison signal to said channel selection device during said third horizontal scanning interval;

sample means for generating a respective sample level for each of said first, second and third horizontal scanning intervals by sampling and holding a level of said received video baseband signal during each of said first, second and third horizontal scanning intervals;

storage means for storing said sample levels generated by said sample means;

comparison means for comparing said sample levels stored in said storage means; and

determining that said input signal is from said predetermined signal source if said stored sample level corresponding to said third horizontal scanninq interval is closer to said stored sample level corresponding to said first horizontal scanning interval than to said stored sample level corresponding to said second horizontal scanning interval.

66. The apparatus of claim 65, wherein:

said input signal is an RF video signal;

said predetermined signal source is a predetermined channel; and

said comparison signal is an RF video signal at a frequency that corresponds to said predetermined channel.

67. Apparatus for determining whether a channel selection device is receiving an input signal from a cable over which a plurality of programs are transmitted simultaneously on respective channels, said cable being selectively connected to said channel selection device, said apparatus comprising:

means for receiving a video baseband signal originating from said channel selection device, said video baseband signal having vertical blanking intervals that each include a plurality of horizontal scanning intervals;

means for separating vertical and horizontal synchronizing signals from the received video baseband signal;

means for selecting first and second ones of said plurality of horizontal scanning intervals;

means for disconnecting said cable from said channel selection device during said second horizontal scanning interval;

sample means for generating a respective sample level for each of said first and second horizontal scanning intervals, by sampling and holding a level of said received video baseband signal during each of said first and second horizontal scanning intervals;

storage means for storing said generated sample levels;

comparison means for comparing said sample levels generated by said sample means; and

means for determining that said channel selection device is not receiving the input signal from said cable if said stored sample levels corresponding to said first and second horizontal scanning intervals differ by less than a predetermined amount.

68. A method of determining whether a predetermined channel selected by a channel selection device has been changed, said channel selection device receiving an input RF video signal, said method comprising the steps of:

receiving a video baseband signal originating from said channel selection device, said video baseband signal having vertical blanking intervals that include a plurality of horizontal scanning intervals;

separating vertical and horizontal synchronizing signals from said received video baseband signal;

selecting a first horizontal scanning interval in a vertical blanking interval of said received video baseband signal;

generating a black reference level by sampling, holding and storing a level of said received video baseband signal during said first horizontal scanning interval;

interrupting said input video signal during a second horizontal scanning interval in said vertical blanking interval;

generating a white reference level by sampling, holding and storing a level of said received video baseband signal during said interruption of said input video signal;

interrupting said input video signal during a third horizontal scanning interval in said vertical blanking interval;

supplying a substitute RF video signal to said channel selection device during said interruption of said input video signal during said third horizontal scanning interval, said substitute RF video signal being at a frequency that corresponds to said predetermined channel;

generating a test level by sampling, holding and storing a level of said received baseband signal while said substitute RF video signal is being supplied to said channel selection device;

comparing said test level to said black and white reference levels; and

determining that said predetermined channel has been changed when said test level is closer to said white reference level than to said black reference level.

69. The method of claim 68 wherein said first, second and third horizontal scanning intervals are consecutive horizontal scanning intervals.

70. The method of claim 68, further comprising repeating all of said steps, other than said determining step in sequence a predetermined number of times.

71. The method of claim 69, wherein a signal level of said substitute RF video signal is increased with each repetition of said supplying step.

72. Apparatus for determining whether a predetermined channel selected by a channel selection device has been changed, said channel selection device receiving an input RF video signal, said apparatus comprising:

means for receiving a video baseband signal originating from said channel selection device, said video baseband signal having vertical blanking intervals that include a plurality of horizontal scanning intervals;

means for separating vertical and horizontal synchronizing signals from said received video baseband signal;

means for selecting a first horizontal scanning interval in a vertical blanking interval of said received video baseband signal;

means for generating a black reference level by sampling, holding and storing a level of said received video baseband signal during said first horizontal scanning interval;

means for interrupting said input video signal during a second horizontal scanning interval in said vertical blanking interval;

means for generating a white reference level by sampling, holding and storing a level of said received video baseband signal during said interruption of said input video signal;

means for interrupting said input video signal during a third horizontal scanning interval in said vertical blanking interval;

means for supplying a substitute RF video signal to said channel selection device during said interruption of said input video signal during said third horizontal scanning interval, said substitute RF video signal being at a frequency that corresponds to said predetermined channel;

means for generating a test level by sampling, holding and storing a level of said received baseband signal while said substitute RF video signal is being supplied to said channel selection device; and

comparison means for comparing said test level to said black and white reference levels and for determining that said predetermined channel has been changed when said test level is closer to said white reference level than to said black reference level.

73. The apparatus of claim 72, wherein said first, second and third horizontal scanning intervals are consecutive horizontal scanning intervals.