COMMUNICATION SYSTEM

• US 3,757,225 A
• Filed: 03/16/1972
• Issued: 09/04/1973
• Est. Priority Date: 03/16/1972
• Status: Expired due to Term

• Current Assignee: Edward M. Ulicki
• Original Assignee: Edward M. Ulicki
• Inventors: Ulicki, Edward M.
• Primary Examiner(s): Britton, Howard W.
• Application Number:
  US05/235,167
• Time in Patent Office: 537 Days
• Field of Search: 178/5.1,6,6.8,DIG.13,DIG.23 179/2TV,15AP 325/308,430,452
• US Class Current: 725/1
• CPC Class Codes: H04N 2007/1739 the upstream communication being transmitted via a separate link, e.g. telephone line
• CPC Class Codes: H04N 7/17345 Control of the passage of the selected programme

Abstract

A communication system by which a plurality of substantially simultaneously transmitted different subscription programs may be selectively individually displayed on a common display channel. A multiplexed communication signal containing a plurality of different program information signals and a plurality of command signals is provided to a plurality of display devices which are capable of displaying different selected program information displays from the plurality of such signals in response to selected program information signals. Each display device has an associated means for controlling the selection of these programs which is connected to a common condition responsive means, such as a computer. The control means includes means for demultiplexing the communication signal and for generating a program information selection control signal in response to a uniquely identified command signal. A digital frequency synthesizer may be utilized to generate the control signal at a frequency which, when mixed with the demultiplexed plurality of subscription program information signals, provides the selected one at the frequency of the common display channel. A different program may be substantially simultaneously selected on another display device in the same manner by the generation of a different control signal frequency in response to a different associated command signal. The plurality of initially demultiplexed program information signals may be a digital time division multiplexed signal, in which instance a digital sampler, such as a recirculating register, may be utilized in conjunction with a comparator to time demultiplex the program information signals and provide the selected program in response to the generation of an unload signal from the comparator as the selection control signal, the output of the sampler being thereafter converted to an analog signal. In addition, the computer and common communication signal path thereto of the communication system may be utilized to provide premises access monitoring, in which instance a pair of input devices, such as a card reader and a door position sensor, provide input conditions to the computer indicative of the status of the door to the premises and the authorization of the entrant, a randomly selected insertable card providing the authorization information to the computer through the reader.

Claims

1. A secure subscription communication system for selectively providing at least two substantially simultaneous displays of different program information from a first multiplexed communication signal containing a plurality of different program information signals and a plurality of command signals, said system comprising at least a first and a second display means for displaying said different program information in response to selected program information signals, each display means having a display signal path over which said program information signals are provided, a common display channel having an associated predetermined signal frequency and a common command signal path;

a first and a second control means operatively connected to said first and second display means, respectively, via said display signal path; and

a first condition responsive means operatively connected to said first and second control means via a common communication signal path, said first multiplexed communication signal being provided to said first and second control means via said communication signal path, said first condition responsive means providing said command signals;

said first and second control means each including an associated first signal separation means for separating said first multiplexed communication signal into said plurality of program information signals and said plurality of command signals, an associated program information selection control signal generating means operatively connected to said associated first signal separating means for providing a program selection control signal in response to an assocIated unique command signal from said first condition responsive means, said program selection control signal generating means associated with said first control means generating a first selection control signal in response to said first control means associated unique command signal, and said program selection control signal generating means associated with said second control means generating a second selection control signal in response to said second control means associated unique command signal, and an associated first signal operating means operatively connected to said associated first signal separating means and said program selection control signal generating means for operating on said plurality of program information signals with said associated program selection control signal for providing one of said selected program information signals to one of said display means at said associated common display signal frequency via said display signal path, said first selection control signal operating on said plurality of program information signals to provide one of at least said two selected program information signals to said first display means for providing one of said substantially simultaneous displays and said second selection control signal operating on said plurality of program information signals to provide said different one of said selected program information signals to said second display means for providing said different one of said substantially simultaneous displays, whereby a plurality of substantially simultaneously transmitted different programs may be selectively displayed on said common display channel.

2. A system in accordance with claim 1 wherein each of said separated plurality of program information signals has a different associated frequency, said associated frequencies being different from each other and from said common display channel associated frequency;

said first and second program information selection control signals have different associated frequencies; and

said first operating means comprises means for combining said first program information selection control signal at its associated frequency with said plurality of program information signals at their respective associated frequencies to provide said one selected program information signal to said first display means at said common display channel associated frequency, and said second operating means comprises means for combining said second program information selection control signal at its associated frequency with said plurality of program information signals at their respective associated frequencies to provide said different one of said selected program information signals to said second display means at said common display channel associated frequency.

3. A system in accordance with claim 2 wherein at least said first combining means is a mixer.

4. A system in accordance with claim 1 wherein said display signal path associated with at least said first display means includes a first filter means operatively connected between said first signal operating means and said first display means for enabling only program information signals at said common display channel frequency to pass to said first display means.

5. A system in accordance with claim 4 wherein said filter means comprises a fixed frequency filter.

6. A system in accordance with claim 1 wherein said first condition responsive means is further connected to a subscription billing means for billing a predetermined charge for said respective selected program information signal in response to said provision of said associated unique command signal to said associated display means.

7. A system in accordance with claim 6 wherein said first condition responsive means is a computer means.

8. A system in accordance with claim 1 wherein at least said first associated signal separation means comprises a first demultiplexer means for demultiplexing said first multiplexed communication signal and passing only saiD plurality of program information signals to said first associated operating means and only said plurality of command signals to said first associated program selection control signal generating means.

9. A system in accordance with claim 8 wherein said first demultiplexer means comprises filter means.

10. A system in accordance with claim 1 wherein said unique command signal includes a unique identifier portion and a command portion and said associated program information selection control signal generating means includes second signal separating means operatively connected to said first signal separating means for separating said unique command signal into said identifier portion and said command portion, means operatively connected to said second signal separating means for generating an identity check control signal in response to an associated predetermined identifier portion, gating means responsive to said identity check control signal operatively connected to said identity check control signal generating means and said second signal separating means for passing said associated command portion in response to said identity check control signal, and means operatively connected to said gating means for generating said selection control signal in response to said command portion.

11. A system in accordance with claim 10 wherein said unique command signal is a digital signal and said second signal separating means is a shift register means.

12. A system in accordance with claim 11 wherein said identity check control signal generating means is a first digital comparator means, said associated display means control means having an associated unique identity reference, said first digital comparator means comparing said unique identity reference with said unique command signal identifier portion for generating said identity check control signal when said identifier portion is equivalent to said unique identity reference.

13. A system in accordance with claim 12 wherein said gating means comprises an AND gate means, said command portion comprises a command information signal input to said AND gate means and said identity check control signal comprises an enable signal input to said AND gate means, said AND gate means passing said command portion only when said enable signal input is present.

14. A system in accordance with claim 10 wherein each of said separated plurality of program information signals has a different associated frequency, said associated frequencies being different from each other and from said common display channel associated frequency;

at least said first program information selection control signal has an associated frequency different from both said program information signal associated frequencies and said common display channel associated frequency;

said first operating means comprises means for combining said first program information selection control signal at its associated frequency with said plurality of program information signals at their respective associated frequencies to provide at least said one selected program information signal to said first display means at said common display channel associated frequency; and

said means for generating said selection control signal in response to said command portion comprises frequency synthesizer means for snythesizing said selection control signal at said selection control signal associated frequency, said frequency synthesizer means comprising a phase locked loop including first signal frequency generating means for generating said selection control signal at said associated frequency thereof, a reference signal generating means for providing a reference signal to said phase locked loop at a predetermined frequency and means for tuning said first signal generating means in said phase locked loop to said selection control signal frequency, said tuning means being operatively connected in said phase locked loop to said reference signal means and said first signal generating means.

15. A system in accordance with claim 14 wherein said first signal generating means selection control generated signal has an associated phase and said reference signal has an associated phase, said first signal generating means selection control phase, frequency being dependent on an associated driving signal for said first signal generating means, a different driving signal resulting in a different selection control signal frequency, said driving signal being provided by said tuning means, and said tuning means includes phase detector means and means operatively connected to said gating means and said first signal generating means for varying said frequency of said generated selection control signal in response to said command portion, said selection control signal frequency varying means providing a comparison signal having an associated frequency and phase to said phase detector, said comparison signal associated frequency being a predetermined fractional multiple of said selection control signal frequency, said fractional multiple being dependent on said command portion, said comparison signal phase being equivalent to said selection control signal phase, said phase detector means comparing said comparison signal and reference signal phases and providing said associated driving signal when said phase locked loop is in an equilibrium state, said equilibrium state occurring when said comparison signal and reference signal frequencies are substantially equivalent and said comparison signal and reference signal phases are separated by a predetermined phase differential.

16. A system in accordance with claim 15 wherein said means for varying said selection control signal frequency to provide said comparison signal comprises a frequency divider means having a variable division ratio, said division ratio varying in response to variations in said command portion.

17. A system in accordance with claim 16 wherein said unique command signal is a digital signal with said command portion being a digital signal, and said frequency divider means comprises a variable length counter means, said comparison signal frequency being dependent on said count length.

18. A system in accordance with claim 17 wherein said counter means is a down counter means.

19. A system in accordance with claim 17 wherein said reference signal and said comparison signal are digital signals, and said phase detector means comprises an AND gate means having said comparison signal as one input thereto and said reference signal as another input thereto, said AND gate means providing said driving signal as a digital signal, said driving signal having a pulse width proportional to said phase differential.

20. A system in accordance with claim 15 wherein said first signal generating means comprises voltage controlled oscillator means whose signal output frequency is dependent on the voltage of said driving signal, and said phase detector means further comprises means for converting said phase differential resulting from said phase comparison into said driving signal voltage.

21. A system in accordance with claim 10 wherein at least said first associated separated plurality of program information signals is a second time division multiplexed signal, said command portion includes a time slot select portion and a program select portion, and said first associated means for generating said selection control signal in response to said command portion comprises second comparator means for comparing said time slot select portion and said program select portion and providing said selection control signal when said time select portion substantially corresponds to said program select portion, each one of said plurality of program information signals in said second multiplexed signal having a different corresponding time slot in said second multiplexed signal.

22. A system in accordance with claim 21 wherein said unique command signal is a digital signal and said second signal separating means is a shiFt register means.

23. A system in accordance with claim 22 wherein said indentity check control signal generating means is a first digital comparator means, said associated display means control means having an associated unique identity reference said first digital comparator means comparing said unique identity reference with said unique command signal identifier portion for generating said identity check control signal when said identifier portion is equivalent to said unique identity reference.

24. A system in accordance with claim 23 wherein said gating means comprises an AND gate means, said command portion comprises a command information signal input to said AND gate means and said identity check control signal comprises an enable signal input to said AND gate means, said AND gate means passing said command portion only when said enable signal input is present.

25. A system in accordance with claim 21 wherein said second multiplexed signal is a digital signal and said associated program information selection control signal is a digital signal, and at least said first associated signal operating means comprises third signal separating means for separating said one selected program information signal from said plurality of program information signals, said digital program information selection control signal and said digital second multiplexed signal being provided to said third signal separating means whereby said program information selection signal operates on said second multiplexed signal to provide said one selected program information signal.

26. A system in accordance with claim 25 wherein said third signal separating means comprises time division demultiplexer means for demultiplexing said second multiplexed signal.

27. A system in accordance with claim 25 wherein said third signal separating means comprises digital sampler means for operating on said second digital multiplexed signal by sampling said second multiplexed signal when said program information selection control signal is provided thereto, said selection control signal being a sampling pulse.

28. A system in accordance with claim 27 wherein said digital sampling means is a circulating shift register means, said sampling pulse being an unload signal therefor, said circulating register digital length being at least substantially equivalent to the digital length of said one program information signal, said sampling pulse unloading said one selected program information signal from said register means.

29. A system in accordance with claim 27 wherein said first operating means further comprises digital-to-analog converting means operatively connected to said digital sampler means for converting said one digital selected program information signal to an analog signal corresponding thereto, said one selected program information corresponding analog signal being provided to said first display means.

30. A system in accordance with claim 29 wherein at least said first display means is an audio-video display means, said program information signals each have a video portion and an associated audio portion, said second multiplexed signal comprises a plurality of associated audio portion signals, said first signal separating means provides a third plurality of multiplexed video portion signals and said second multiplexed signal, said first signal separating means further comprises means for demultiplexing said third multiplexed signal for providing said one selected program information signal video portion, said converting means provides said one selected program information signal associated audio portion as said analog signal, and said system further includes a combining means operatively connected to said converting means, said demultiplexer means and said first display means in said display signal path for combining said one selected program information audio and video portions to provide said one selected program information signal to said first display means.

31. A systeM for providing secure subscription communication and premises access monitoring wherein said system selectively provides a display of program information from a first multiplexed communication signal containing a plurality of different program information signals and at least one command signal, said system comprising at least a first display means for displaying said selected program information in response to one of said selected program information signals, said display means having a display signal path over which said program information signals are provided, a common display channel having an associated predetermined signal frequency and a common command signal path;

a first control means operatively connected to said first display means via said display signal path; and

a first condition responsive means operatively connected to said first control means via a common communication signal path, said first multiplexed communication signal being provided to said first control means via said communication signal path, said first condition responsive means providing said command signal;

said first control means including an associated first signal separation means for separating said first multiplexed communication signal into said plurality of program information signals and said command signal, an associated program information selection control signal generating means operatively connected to said associated first signal separating means for providing a program selection control signal in response to an associated unique command signal from said first condition responsive means, said program selection control signal generating means associated with said first control means generating a first selection control signal in response to said first control means associated unique command signal, and an associated first signal operating means operatively connected to said associated first signal separating means and said program selection control signal generating means for operating on said plurality of program information signals with said associated program selection control signal for providing said selected one of said program information signals to said display means at said associated common display signal frequency via said display signal path, said first selection control signal operating on said plurality of program information signals to provide said selected program information signal to said first display means for providing said selected display, whereby a plurality of substantially simultaneously transmitted different programs may be selectively individually displayed on said common display channel; and

said system further comprises an identity code input means operatively connected to said first condition responsive means via said communication signal path to provide a first identity input condition thereto and an access status monitoring means operatively connected to said first condition responsive means via said communication signal path to provide a second access status input condition thereto, said first condition responsive means providing an alert output signal condition in response to said first and second input conditions when said input conditions are provided thereto and said first input condition does not correspond to a predetermined authorized identity code signal, whereby an alert to unauthorized entry of an access monitored premises may be provided.

32. A system in accordance with claim 31 wherein said access monitored premises has a means for obtaining physical access to said premises, said access status monitoring means comprises bistable means having an accessed condition and an unaccessed condition, said access status input condition being provided in said accessed condition, said bistable means being operatively connected to said physical access obtaining means and to said first condition responsive means via said communication signal path for providing said access status input condition thereto, and said identity code input means comprises card reader means, said identity code being contained on a card means insertable in said reader means, said reader means being operatively connected to said first condition responsive means via said communication signal path for providing said first input condition thereto in response to said identity code of an inserted card means, only one identity code corresponding to said predetermined authorized identity code signal.

33. In a secure subscription communication system for selectively providing at least one display of program information from a first multiplexed communication signal containing a plurality of different program information signals and at least one command signal, said system comprising at least a first display means for displaying said selected program information in response to one of said selected program information signals, said display means having a display signal path over which said program information signals are provided, a common display channel having an associated predetermined signal frequency and a common command signal path;

and a first condition responsive means, said first condition responsive means providing said command signal;

the improvement comprising a first control means operatively connected to said first display means via said display signal path and to said first condition responsive means via said common communication signal path, said first multiplexed communication signal being provided to said first control means via said communication signal path, said first control means including an associated first signal separation means for separating said first multiplexed communication signal into said plurality of program information signals and said command signal, an associated program information selection control signal generating means operatively connected to said associated first signal separating means for providing a program selection control signal in response to an associated unique command signal from said first condition responsive means, said program selection control signal generating means associated with said first control means generating a first selection control signal in response to said first control means associated unique command signal, and an associated first signal operating means operatively connected to said associated first signal separating means and said program selection control signal generating means for operating on said plurality of program information signals with said associated program selection control signal for providing said selected one of said program information signals to said display means at said associated common display signal frequency via said display signal path, said first selection control signal operating on said plurality of program information signals to provide said selection program information signal to said first display means for providing said selected program information display;

said unique command signal includes a unique identifier portion and a command portion and said associated program information selection control signal generating means includes second signal separating means operatively connected to said first signal separating means for separating said unique command signal into said identifier portion and said command portion, means operatively connected to said second signal separating means for generating an identity check control signal in response to an associated predetermined identifier portion, gating means responsive to said identity check control signal operatively connected to said identity check control signal generating means and said second signal separating means for passing said associated command portion in response to said identity check control signal, and means operatively connected to said gating means for generating said selection control signal in response to said command portion.

34. An improved system in accordance with claim 33 wherein said unique command signal is a digital signal and said second signal separating means is a shifT register means.

35. An improved system in accordance with claim 33 wherein each of said separated plurality of program information signals has a different associated frequency, said associated frequencies being different from each other and from said common display channel associated frequency;

said first program information selection control signal has an associated frequency different from both said program information signal associated frequencies and said common display channel associated frequency;

said first operating means comprises means for combining said first program information selection control signal at its associated frequency with said plurality of program information signals at their respective associated frequencies to provide said selected program information signal to said first display means at said common display channel associated frequency; and

said means for generating said selection control signal in response to said command portion comprises frequency synthesizer means for synthesizing said selection control signal at said selection control signal associated frequency, said frequency synthesizer means comprising a phase locked loop including first signal frequency generating means for generating said selection control signal at said associated frequency thereof, a reference signal generating means for providing a reference signal to said phase locked loop at a predetermined frequency and means for tuning said first signal generating means in said phase locked loop to said selection control signal frequency, said tuning means being operatively connected in said phase locked loop to said reference signal means and said first signal generating means.

36. An improved system in accordance with claim 35 wherein said first signal generating means selection control generated signal has an associated phase and said reference signal has an associated phase, said first signal generating means selection control signal frequency being dependent on an associated driving signal for said first signal generating means, a different driving signal resulting in a different selection control signal frequency, said driving signal being provided by said tuning means, and said tuning means includes phase detector means and means operatively connected to said gating means and said first signal generating means for varying said frequency of said generated selection control signal in response to said command portion for providing a comparison signal having an associated frequency and phase to said phase detector, said comparison signal associated frequency being a predetermined fractional multiple of said selection control signal frequency, said fractional multiple being dependent on said command portion, said comparison signal phase being equivalent to said selection control signal phase, said phase detector means comparing said comparison signal and reference signal phases and providing said associated driving signal when said phase locked loop is in an equilibrium state, said equilibrium state occurring when said comparison signal and reference signal frequencies are substantially equivalent and said comparison signal and reference signal phases are separated by a predetermined phase differential.

37. An improved system in accordance with claim 36 wherein said means for varying said selection control signal frequency to provide said comparison signal comprises a frequency divider means having a variable division ratio, said division ratio varying in response to variations in said command portion.

38. An improved system in accordance with claim 37 wherein said unique command signal is a digital signal with said command portion being a digital signal, said frequency divider means comprising a variable length counter means, said comparison signal frequency being dependent on said count length.

39. An improved system in accordance with claim 36 wherein said first signal generating means comprises voltage controlled oscillator means whose signal output frequency is dEpendent on the voltage of said driving signal, and said phase detector means further comprises means for converting said phase differential resulting from said phase comparison into said driving signal voltage.

40. An improved system in accordance with claim 33 wherein at least said first associated separated plurality of program information signals is a second time division multiplexed signal, said command portion includes a time slot select portion and a program select portion, and said first associated means for generating said selection control signal in response to said command portion comprises second comparator means for comparing said time slot select portion and said program select portion and providing said selection control signal when said time select portion substantially corresponds to said program select portion, each one of said plurality of program information signals in said second multiplexed signal having a different corresponding time slot in said second multiplexed signal.

41. An improved system in accordance with claim 40 wherein said second multiplexed signal is a digital signal and said associated program information selection control signal is a digital signal, and at least said first associated signal operating means comprises third signal separating means for separating said one selected program information signal from said plurality of program information signals, said digital program information selection control signal and said digital second multiplexed signal being provided to said third signal separating means whereby said program information selection signal operates on said second multiplexed signal to provide said one selected program information signal.

42. An improved system in accordance with claim 41 wherein said third signal separating means comprises time division demultiplexer means for demultiplexing said second multiplexed signal.

43. An improved system in accordance with claim 41 wherein said third signal separating means comprises digital sampler means for operating on said second digital multiplexed signal by sampling said second multiplexed signal when said program information selection control signal is provided thereto, said selection control signal being a sampling pulse.

44. An improved system in accordance with claim 43 wherein said digital sampling means is a circulating shift register means, said sampling pulse being an unload signal therefor, said circulating register digital length being at least substantially equivalent to the digital length of said one selected program information signal, said sampling pulse unloading said one selected program information signal from said register means.

45. An improved system in accordance with claim 43 wherein said first operating means further comprises digital-to-analog converting means operatively connected to said digital sampler means for converting said one digital selected program information signal to an analog signal corresponding thereto, said one selected program information corresponding analog signal being provided to said first display means.