COMPUTER ASSISTED DIAL ACCESS VIDEO RETRIEVAL FOR AN INSTRUCTIONAL TELEVISION SYSTEM

• US 3,729,581 A
• Filed: 09/03/1970
• Issued: 04/24/1973
• Est. Priority Date: 09/03/1970
• Status: Expired due to Term

• Current Assignee: Deyrol E. Anderson
• Original Assignee: Deyrol E. Anderson
• Inventors: Anderson, Deyrol E.
• Primary Examiner(s): Griffin, Robert L.
• Assistant Examiner(s): Orsino, Jr., Joseph A.
• Application Number:
  US05/069,312
• Time in Patent Office: 964 Days
• Field of Search: 178/DIG.22,5.6,5.8 340/147,171 325/37,55,64
• US Class Current: 348/460
• CPC Class Codes: H04N 2007/1739 the upstream communication being transmitted via a separate link, e.g. telephone line
• CPC Class Codes: H04N 7/162 Authorising the user terminal, e.g. by paying; Registering the use of a subscription channel, e.g. billing
• CPC Class Codes: H04N 7/17318 Direct or substantially direct transmission and handling of requests

Abstract

An instructional television system is provided for making available non-print learning materials upon request. The instructional system includes a central library store for storage of programs of learning materials. Learning materials are selectively transmitted via a TV transmitter link after being addressed with a predetermined three variable (tone, duration and period of silence) code. The code serves to '"'"''"'"''"'"''"'"'unclock'"'"''"'"''"'"''"'"' or activate one or more decoders disposed at a plurality of subscriber stations through a TV receiver at the corresponding subscriber station. Each decoder at a subscriber station can be programmed to any one of a plurality of two-tone sequential codes. The activated encoder serves to actuate an associated video tape recorder to record the selected transmitted material after which all remote subscriber video tape recorders previously activated by the coded transmission signal are deactivated.

Claims

1. An instructional television system for making available nonprint learning materials from a central library store of programs of learning materials, means for transmitting selected programs via a television transmitter link, means for addressing said selected programs with a predetermined call code signal comprising at least two sequential tone pulses each having a discrete frequency and being of a specific duration with adjacent tone pulses being separated by a preselected time interval in which no tone generated signals are present and a single tone deactivation code signal, a plurality of subscriber stations each including a television monitor receiver for receiving the transmitted programs, a decoder connected to each receiver and a video tape recorder for selectively recording transmitted programs, each decoder at a subscriber station being programmed to detect one of a plurality of said call code signals and including first means for activating an associated video tape recorder to record the selected transmitted material in response to a detected call code signal at that decoder and second means for deactivating the associated video tape recorder in response to the detection of said single tone deactivation code signal at that decoder, each said decoder including a pair of electromechanical frequency detectors, one of said detectors being programmed to respond to the sequential tone pulses of a call code signal, the other of said detectors being responsive to said single tone deactivation code signal, and said first means for activating an associated recorder includes a first relay control connected to the programmed detector and having a first set of contacts adapted to establish an energizing circuit for activation of said video tape recorder upon the detection of said call code signal and a delay circuit for delaying the record function of said video tape recorder a predetermined period, said second means for deactivating the recorder including a second relay control connected to the other of said detectors and having a set of contacts connected in the first relay control and adapted to disable said first relay control in response to the detection of said single tone deactivation code.

2. An instructional television system as set forth in claim 1 wherein said first means further includes a time duration detector circuit adapted to measure the time interval between sequential pulses and means operatively connecting said circuit to said first relay control, and said second means further includes a time duration detector circuit adapted to allow said second relay control to be energized only when said single tone deactivation code signal is present for a predetermined period.

3. An instructional television system as set forth in claim 1 wherein said call code signal comprises two individual tones, each tone being approximately one second in duration, said tones being spaced from each other in time by a period of approximately 200 milliseconds and said single tone deactivation signal having a duration of approximately three seconds.

4. An instruction television system as set forth in claim 1 further including a central store for storing the prerecorded instructional programs in the form of video tapes, means for selecting video tapes from said store and transmitting an instructional program prerecorded on the selected tape including encoder means for coding said transmitted program by modulating the auRal carrier of the transmitter with a multi-tone activating call signal and a single tone deactivating signal.

5. An instructional, television system for transmitting via a television transmitting link prerecorded instructional programs from a central television transmitting station to be received at one or more remotely situated receiver stations comprising a central store having prerecorded instructional programs, means for selecting and transmitting an instructional program from said store including encoder means for addressing said transmitted program with an activating call signal comprising at least two sequential tone pulses each having a discrete frequency and being of a specific duration with adjacent tone pulses being separated by a preselected time interval in which no tone generated signals are present and a single tone deactivating signal, television receiver means disposed at each receiver station for receiving said coded transmitted program and separating said tone signals from the program information, a decoder means, operatively connected to each receiver to receive said separated signals each said decoder at a remote location being responsive to a unique call signal and to said single tone signal, a normally deactivated video tape recorder connected to each receiver means, for recording a transmitted program, said decoder including first means for activating said video tape recorder from the associated decoder in response to detection of the unique call signal at that decoder to enable recording of the transmitted program and second means for deactivating all said video tape recorders previously activated in response to detection of said single tone signal, each said decoder including means for connecting the input thereto to the audio output of the associated receiver and a pair of electromechanical frequency detectors, one of said detectors being programmed to respond to a multi-tone sequential call code, the other of said detectors being responsive to said single tone deactivation code, and said first means for activating an associated recorder includes a first relay control connected to the programmed detector and having a first set of contacts adapted to establish an energizing circuit for activation of said video tape recorder upon the detection of said two-tone sequential code, and said first means further including a delay circuit for delaying the record function of said video tape recorder a predetermined period, said second means for deactivating the recorder including a second relay control connected to the other of said detectors and having a set of contacts connected in the first relay control, said contacts being arranged to disable said first relay control in response to the detection of said single tone deactivation code, said first means further including a time duration detector circuit adapted to measure the time interval between sequential pulses, and means operatively connecting said circuit to said first relay control, and said second means further including a time duration circuit adapted to allow said second relay control to be enabled only when said single tone deactivation code signal is present for a predetermined period.

6. An instructional television system as set forth in claim 5 wherein said call code signal comprises two individual tones of a fixed duration and of a fixed frequency, each tone being approximately one second in duration, said tones being spaced from each other in time by a period of approximately 200 milliseconds, and said single tone deactivation signal is approximately three seconds in duration.

7. An instruction television system for transmitting prerecorded instructional programs from a central transmitting station to one or more remotely situated receiver stations comprising a central store for storing the prerecorded instructional programs in the form of video tapes, means for selecting video tapes from said store and transmitting an instructional program prerecorded on the selected tape inCluding encoder means for coding said transmitted program by modulating the aural carrier of the transmitter with a multi-tone activating call signal and a single tone deactivating signal, said encoder including a plurality of oscillators selectably operable to provide the sequential tone signals, a first AND gate, a second AND gate, means connecting one input of said AND gates to said oscillators, a first timing circuit, a second timing circuit, a delay network interconnecting said timing circuits such that an output from the second timing circuit is initiated upon the completion of the timing of said first timing circuit, but with a delay dependent on said delay network and means connecting said first timing circuit to said first AND gate and said second timing circuit to said second AND gate, and means for connecting the outputs of said AND gates to said transmitter to modulate the aural carrier.

8. An instructional television system for making available non-print learning materials from a central library store of programs of learning materials, means for transmitting selected programs via a television transmitter link, means for addressing said selected programs with a predetermined call code signal comprising at least two sequential tone pulses each having a discrete frequency and being of a specific duration with adjacent tone pulses being separated by a preselected time interval in which no tone generated signals are present and a single tone deactivation code signal, a plurality of subscriber stations each including a television monitor receiver for receiving the transmitted programs, a decoder connected to each receiver and a video tape recorder for selectively recording transmitted programs, each decoder at a subscriber station being programmed to detect one of a plurality of said call code signals and including first means for activating an associated video tape recorder to record the selected transmitted material in response to a detected call code signal at that decoder and second means for deactivating the associated video tape recorder in response to the detection of said single tone deactivation code signal at that decoder, said means for transmitting including an encoder having a plurality of oscillators selectably operable to provide the sequential tone signals, a first AND gate, a second AND gate means connecting one input of said AND gates to said oscillators, a first timing circuit, a second timing circuit, a delay network interconnecting said timing circuits such that an output from the second timing circuit is initiated upon the completion of the timing of said first timing circuit, but with a delay dependent on said delay network and means connecting said first timing circuit to said first AND gate and said second timing circuit to said second AND gate, and means for connecting the outputs of said AND gates to said transmitter to modulate the aural carrier.

9. An instructional, television system for transmitting via a television transmitting link prerecorded instructional programs from a central television transmitting station to be received at one or more remotely situated receiver stations comprising a central store having prerecorded instructional programs, means for selecting and transmitting an instructional program from said store including encoder means for addressing said transmitted program with an activating call signal comprising at least two sequential tone pulses each having a discrete frequency and being of a specific duration with adjacent tone pulses being separated by a preselected time interval in which no tone generated signals are present and a single tone deactivating signal, television receiver means disposed at each receiver station for receiving said coded transmitted program and separating said tone signals from the program information, a decoder means, operatively connected to each receiver to receive said separated signals each said decoder at a remote location being responsive to a unique call signal And to said single tone signal, a normally deactivated video tape recorder connected to each receiver means, for recording a transmitted program, said decoder including first means for activating said video tape recorder from the associated decoder in response to detection of the unique call signal at that decoder to enable recording of the transmitted program and second means for deactivating all said video tape recorders previously activated in response to detection of said single tone signal, each encoder means including a plurality of oscillators selectably operable to provide the sequential tone signals, a first AND gate, a second AND gate means connecting one input of said AND gates to said oscillators, a first timing circuit, a second timing circuit, a delay network interconnecting said timing circuits such that an output from the second timing circuit is initiated upon the completion of the timing of said first timing circuit abut with a delay dependent on said delay network and means connecting said first timing circuit to said first AND gate and said second timing circuit to said second AND gate, and means for connecting the outputs of said AND gates to said transmitter to modulate the aural carrier.

10. An instructional television system for transmitting and receiving prerecorded instructional programs comprising a central television transmitting station for transmitting to one or more remotely situated receiver stations selectively precoded video programs coded with an activating call signal comprising at least two sequential tone pulses each having a discrete frequency and being of a specific duration with adjacent tone pulses being separated by a preselected time interval in which no tone generated signals are present and a single tone deactivating signal means for modulating the aural carrier of the television signal with the call signal television receiver means disposed at each receiver station for receiving the modulated aural carrier and video transmitted program and separating said tone signals from the modulated aural carrier and video program information, a decoder connected to each receiver means, each said decoder being responsive to a unique multi-tone call signal and all said decoders being responsive to said single tone signal, a normally deactivated video tape recorder separately connected to each receiver means and to each associated decoder, each said decoder including a pair of electro-mechanical frequency detectors, one of said detectors being programmed to respond to a call code signal, the other of said detectors being responsive to said single tone deactivating signal, first means for activating an associated recorder including a first relay control connected to the programmed detector and having a first set of contacts adapted to establish an energizing circuit for activation of said video tape recorder upon the detection of said two-tone sequential code, said first means further including a delay circuit for delaying the record function of said video tape recorder a predetermined period and second means for deactivating the recorder including a second relay control connected to the other of said detectors and having a set of contacts connected in the first relay control and adapted to disable said first relay control in response to the detection of said single tone deactivation code said first means having a time duration detector circuit adapted to measure the time interval between sequential pulses and means operatively connecting said circuit to said first relay control and said second means further including a time duration circuit adapted to allow said second relay control to be enabled only when said single tone deactivation code signal is present for a predetermined period of at least three seconds and said call code signal comprises individual tones of a fixed duration and of a fixed frequency, each said individual approximately one second in duration, and spaced from each other in time by a period of approximately 200 milliseconds.