Video tape recorder with editing feature and improved tape speed control

Claim 3

Apparatus for controlling the magnetic tape speed of a video tape recorder during editing comprising first circuit means for controlling the speed of the magnetic tape drive by first series of spaced-apart control pulses from the magnetic video tape during the playback mode of operation, second circuit means for controlling the speed of the magnetic tape drive by a second series of spaced-apart pulses in synchronism witH the vertical sync pulses of an incoming video signal during the record mode of operation, and means for switching from said first circuit means to said second circuit means in switching from said playback mode of operation to said record mode of operation, the improvement comprising means in at least said second circuit means for multiplying the frequency of occurrence of the pulses of said first and second series of pulses by substantially the same selected factor.

Claim 4

Apparatus for controlling the magnetic tape speed of a video tape recorder during editing comprising first circuit means for controlling the speed of the magnetic tape drive by first series of spaced-apart control pulses from the magnetic video tape during the playback mode of operation, second circuit means for controlling the speed of the magnetic tape drive by a second series of spaced-apart pulses in synchronism witH the vertical sync pulses of an incoming video signal during the record mode of operation, and means for switching from said first circuit means to said second circuit means in switching from said playback mode of operation to said record mode of operation, the improvement comprising means in at least said second circuit means for multiplying the frequency of occurrence of the pulses of said first and second series of pulses by substantially the same selected factor.

Claim 5

Apparatus as claimed in claim 2 including divider circuit means coupled to the magnetic tape drive for reducing the number of pulses of both series by the same factor that they had been increased.

Claim 6

A video tape recorder comprising a rotating head for recording video signals on a magnetic tape during the record mode of operation and for playing back video signals from a magnetic tape during the playback mode of operation, a tape drive circuit for driving the video tape relative to said head, means for driving said head in synchronism with the vertical sync pulse of an incoming video signal and for producing a control pulse on the video tape during the record mode in synchronism with the head rotation, means for deriving a control signal from the rotating head and control pulse on a video tape during the playback mode, first circuit means for coupling said tape drive circuit to said rotating head during the record mode to control the tape speed in response to the speed of rotation of the rotating head, and second circuit means for coupling said tape drive circuit to the control signal deriving means during the playback mode to control the tape speed in response to the rotating head and control pulse, wherein the improvement comprises a multiplier means in said first circuit means for multiplying the frequency of the rotary head a selected factor and a multiplier means in said second circuit means for multiplying the frequency of said control signal by substantially the same selected factor, and a divider means coupled to said tape drive circuit for dividing the frequency of the control signals from said first and second circuit means by said selected factor.

Claim 7

A video tape recorder comprising a rotating head for recording video signals on a magnetic tape during the record mode of operation and for playing back video signals from a magnetic tape during the playback mode of operation, a tape drive circuit for driving the video tape relative to said head, means for driving said head in synchronism with the vertical sync pulse of an incoming video signal and for producing a control pulse on the video tape during the record mode in synchronism with the head rotation, means for deriving a control signal from the rotating head and control pulse on a video tape during the playback mode, first circuit means for coupling said tape drive circuit to said rotating head during the record mode to control the tape speed in response to the speed of rotation of the rotating head, and second circuit means for coupling said tape drive circuit to the control signal deriving means during the playback mode to control the tape speed in response to the rotating head and control pulse, wherein the improvement comprises a multiplier means in said first circuit means for multiplying the frequency of the rotary head a selected factor and a multiplier means in said second circuit means for multiplying the frequency of said control signal by substantially the same selected factor, and a divider means coupled to said tape drive circuit for dividing the frequency of the control signals from said first and second circuit means by said selected factor.

Claim 10

A video tape recorder comprising a rotating video head for recording video signals on a magnetic tape during the record mode of operation and for playing back video signals from a magnetic tape during the playback mode of operation, a drive motor for driving the video tape relative to said rotating head, a power amplifier circuit for regulating the speed of said tape drive motor, means for driving said video head in synchronism with the vertical sync pulse of an incoming video signal and for producing control signals on the video tape in synchronism with the video head rotation, first circuit means coupled to said rotating video head for producing a series of control pulses in synchronism with the rotating head during the record mode of operation, second circuit means coupled to the control signals on the video tape and to the rotating video head for producing a series of control pulses from the tape during the playbaCk mode of operation, and switch means for coupling the tape drive power amplifier to said first circuit means during the record mode and coupling the tape drive power amplifier to said second circuit means during the playback mode whereby the speed of said tape may be controlled in synchronism with the pulses from said first and second circuit means, the improvement comprising means in said first circuit means for multiplying the frequency of said control pulses by a selected factor relative to the revolutions of said video head and means in said circuit means for multiplying the frequency of said control pulses by substantially the same factor relative to the control signals on the tape, and divider means coupled to said power amplifier for dividing the multiplied series of control pulses by the same factor.

Claim 11

A video tape recorder comprising a rotating video head for recording video signals on a magnetic tape during the record mode of operation and for playing back video signals from a magnetic tape during the playback mode of operation, a drive motor for driving the video tape relative to said rotating head, a power amplifier circuit for regulating the speed of said tape drive motor, means for driving said video head in synchronism with the vertical sync pulse of an incoming video signal and for producing control signals on the video tape in synchronism with the video head rotation, first circuit means coupled to said rotating video head for producing a series of control pulses in synchronism with the rotating head during the record mode of operation, second circuit means coupled to the control signals on the video tape and to the rotating video head for producing a series of control pulses from the tape during the playbaCk mode of operation, and switch means for coupling the tape drive power amplifier to said first circuit means during the record mode and coupling the tape drive power amplifier to said second circuit means during the playback mode whereby the speed of said tape may be controlled in synchronism with the pulses from said first and second circuit means, the improvement comprising means in said first circuit means for multiplying the frequency of said control pulses by a selected factor relative to the revolutions of said video head and means in said circuit means for multiplying the frequency of said control pulses by substantially the same factor relative to the control signals on the tape, and divider means coupled to said power amplifier for dividing the multiplied series of control pulses by the same factor.

Claim 12

A video tape recorder as claimed in claim 6 wherein said means in said first circuit means for multiplying the frequency of said control pulses comprises a voltage-controlled oscillator and wherein said means in said second circuit means for multiplying the frequency of said control pulses comprises a second voltage-controlled oscillator.

Claim 13

A video tape recorder as claimed in claim 6 wherein said means in said first circuit means for multiplying the frequency of said control pulses comprises a tachometer coupled to said video head drive motor and wherein said means in said second circuit means for multiplying frequency of said control pulses comprises a voltage-controlled oscillator.

Claim 14

A video tape recorder as claimed in claim 8 wherein said second circuit means comprises a phase detector circuit for comparing the pulses from the control signal on the tape with tachometer pulses from the video head, the output of the phase detector controlling the frequency of said voltage-controlled oscillator.

Claim 15

Apparatus for reducing phase discontinuities in the tape speed servocontrol of a recorder at the playback to record transition comprising means for deriving a reference signal having a frequency Fv, means for deriving a signal from the tape during playback having a frequency of about Fv, means receiving said reference signal and tape signal for generating a playback tape speed servocontrol signal in response thereto, said last recited signal having a frequency of at least 8 Fv, means for deriving a record tape speed servo control signal having a frequency substantially equal to said playback tape servocontrol signal, and means receiving said playback tape speed servocontrol signal during record for controlling the speed of said tape.

Claim 16

Apparatus for reducing phase discontinuities in the tape speed servocontrol of a recorder at the playback to record transition comprising means for deriving a reference signal having a frequency Fv, means for deriving a signal from the tape during playback having a frequency of about Fv, means receiving said reference signal and tape signal for generating a playback tape speed servocontrol signal in response thereto, said last recited signal having a frequency of at least 8 Fv, means for deriving a record tape speed servo control signal having a frequency substantially equal to said playback tape servocontrol signal, and means receiving said playback tape speed servocontrol signal during record for controlling the speed of said tape.

Claim 17

Apparatus according to claim 10 wherein said tape speed control means includes means for dividing the frequency of said playback and record tape speed servocontrol signals to provide a tape speed signal having a substantially equal frequency to Fv. 12 Apparatus according to claim 11 wherein said playback tape speed servocontrol signal generating means comprises means for comparing the phase of said reference signal and tape signal to provide a phase difference signal in response thereto, and means for generating said playback tape speed servocontrol signal in response to said phase difference signal.

Claim 18

Apparatus according to claim 12 wherein said reference signal is derived from the vertical sync pulses of an incoming video signal.

Claim 19

Apparatus according to claim 13 wherein said recorder has a rotating record transducer and record tape speed servocontrol signal synchronized with the velocity of said record transducer means.

Claim 20

Apparatus according to claim 14 wherein said tape speed control means includes a capstan and capstan drive motor, said drive motor receiving said tape speed signal.

Claim 21

Apparatus according to claim 14 wherein said tape derived signal is derived from a control track signal recorded on said tape.

Claim 22

Apparatus according to claim 14 wherein said playback tape speed servocontrol signal has a frequency on the order of 256v.