Digital logic control for audio visual programs and method therefor

Claim 1

For use with a visual projector having a photographic program therein which may be remotely advanced or reversed in frame increments, a control system for synchronizing an audio tape with the photographic program regardless of tape speed and direction comprising: a magnetic tape player having a multiple pole head, for audio program and control signal detection, a play switch, modulated programmed reset switches, cue and review switches for controlling the tape drive motor, a tape having an audio track on which is recorded the audio program to be synchronized with the photographic program and having a signal track on which has been recorded a tape stop modulatible tone and a projector frame change tone, a logic circuit connected in circuit with a signal pole of said tape head, the tape drive motor and adapted to be connected to the reversible visual projector, so that if the play switch is closed actuating the tape motor and magnetic tape player, and the detected control signal is a tape stop tone, the logic circuit identifies it and opens the power supply line to the tape drive motor causing the tape player to stop, said reset switches being in circuit with said tape drive motor so that said tape drive motor cannot be restarted until the proper reset switch as programmed by the stop tone modulation is closed, if the detected control signal is a frame change tone said logic identifies it and sends a frame advancing signal to said visual projector to advance the photographic program one frame, upon closing said play and cue switches and said detected control signal is a frame change tone said logic identifies it and sends an advance command to the visual projector to advance the photographic program one frame and to the tape drive motor to pause while photographic program advances one frame, said logic ignoring tape stop modulatible tones, when play and cue switches are closed; upon closing said play and review switches and said detected control signal is a frame change tone said logic identifies it and sends a reverse command to the visual projector to reverse the photographic program one frame and to said tape drive motor to pause while photographic program reverses one frame, said logic ignoring tape stop modulatible tones when play and review switches are closed, upon play and cue switches remaining closed and said detected control signals are frame change tones said logic identifies them and sends advance commands to the visual projector to advance the photographic program one frame simultaneously causing said tape drive motor to pause while said photographic program advances one frame as each control signal is detected, said logic ignoring tape stop modulatible tones; upon play and review switches remaining closed and said detected control signals are frame change tones said logic identifies them and sends reverse commands to the visual projector to reverse the photographic program one frame simultaneously causing said tape drive motor to pause while said photographic program reverses one frame as each control signal is detected, said logic ignoring tape stop modulatible tones; said logic including a clock, counters, comparator and a control signal preamplifier in circuit with said tape drive motor and visual projector, said switches and multiple pole head, whereby said control signal detected by said multiple pole head and fed to said control signal preamplifier which feeds two counters in circuit with one another so that upon receipt of a tape stop modulatible tone counter one is at positive logic level and counter two is zero logic level and upon receipt of a frame change tone counter one and counter two are both positive logic level which through said comparator controls the tape drive motor and the visual projector by the programming and sequencing of said switches, said clock causing all logic circuit operations to be synchronous and not subject to transient interference.

Claim 5

The method of logically controlling an audio visual program by magnetic tape comprising: a. preparing a tape having two tracks, one of which carries an audio program to describe the visual program and a signal track which carries two detectable control tones one of which is a tape stop tone and the other of which is a projector frame change tone, and said tape being driven by a drive motor having off time during which the tape drive stops momentarily while the visual program changes one frame, b. subjecting the detected signal control tones of the signal track to a digital logic circuit with combinations of play, review and cue switch closures which provide a first and second operating mode for the digital circuit, said digital circuit in a first mode controlling the audio program on the tape in sync with the projector frame presentation regardless of tape speed or direction, and c. in a second mode to provide adjustable and automatic control of the "off" time, of the drive motor during advance or reverse signals allowing the control of projectors with differing operating speeds and characteristics to complete an operation while searching the tape in high speed either varying or constant, either forward or reverse.

Claim 6

The method of logically controlling an audio visual program by magnetic tape comprising: a. preparing a tape having two tracks, one of which carries an audio program to describe the visual program and a signal track which carries two detectable control tones one of which is a tape stop tone and the other of which is a projector frame change tone, and said tape being driven by a drive motor having off time during which the tape drive stops momentarily while the visual program changes one frame, b. subjecting the detected signal control tones of the signal track to a digital logic circuit with combinations of play, review and cue switch closures which provide a first and second operating mode for the digital circuit, said digital circuit in a first mode controlling the audio program on the tape in sync with the projector frame presentation regardless of tape speed or direction, and c. in a second mode to provide adjustable and automatic control of the "off" time, of the drive motor during advance or reverse signals allowing the control of projectors with differing operating speeds and characteristics to complete an operation while searching the tape in high speed either varying or constant, either forward or reverse.