Digital video signal reproducing apparatus

Claim 2

A digital video signal reproducing apparatus including a capstan (8) for driving a magnetic tape (2) and a drum (1) having a plurality of magnetic heads (PB1 to PB4) for scanning tracks of said magnetic tape, said capstan and said drum being driven at a non-standard speed so as to reproduce and store data, recorded on said magnetic tape, in a memory and to carry out compression and expansion of the recorded data in reproduction, said apparatus comprising: command signal generating means (86) for generating a command signal in the reproduction so as to instruct compression and expansion of the recorded data including video data and audio data; and data extracting means (19, 20) for controlling the characteristic of said recorded data in response to said command signal so that said recorded data can be transferred at a data transfer rate required for processing said recorded data.

Claim 3

A digital video signal reproducing apparatus according to Claim 1, wherein said command signal generating means includes a relative speed detecting circuit (86) detecting a relative speed which is the vector sum of the moving speed of said magnetic tape (2) and the rotation speed of said drum (1) thereby generating a relative speed signal based on the detected relative speed, and said data extracting means includes at least one data extracting circuit (19, 20) including a waveform equalizer circuit (28) for equalizing the frequency of said recorded data to that having a predetermined frequency characteristic in response to said relative speed signal so as to eliminate waveform interference from said recorded data, so that said recorded data can be transferred at a data transfer rate required for process­ing said recorded data, a clock extracting circuit (30) quantizing the equalized recorded data thereby generating a clock signal determined on the basis of said quantized recorded data, and a data strobe circuit (31) sampling said quantized recorded data by said clock signal thereby generating said recorded data from which jitter is removed.

Claim 4

A digital video signal reproducing apparatus including a capstan (8) for driving a magnetic tape (2) and a drum (1) having a plurality of magnetic heads (PB1 to PB4) for scanning tracks of said magnetic tape, said capstan and said drum being driven at a non-standard speed so as to reproduce and store data, recorded on said magnetic tape, in a memory and to carry out compression and expansion of recorded data in reproduction, said apparatus comprising: a tension detecting circuit (97) detecting the tension of said magnetic tape thereby generating a tape tension signal; a tape tension reference signal generating circuit (97′) generating a speed command signal instructing the rotation speed of a reel having said magnetic tape wound therearound; an arithmetic circuit (98) computing the phase difference between said speed command signal and said tape tension signal thereby generating a phase difference signal; and a tape reel driver (99) generating, in response to said phase difference signal, a drive signal for driving said tape reel.

Claim 5

A digital video signal reproducing apparatus including a capstan (8) for driving a magnetic tape (2) and a drum (1) having a plurality of magnetic heads (PB1 to PB4) for scanning tracks of said magnetic tape, said capstan and said drum being driven at a non-standard speed so as to reproduce and store data, recorded on said magnetic tape, in a memory and to carry out compression and expansion of recorded data in reproduction, said apparatus comprising: a tension detecting circuit (97) detecting the tension of said magnetic tape thereby generating a tape tension signal; a tape tension reference signal generating circuit (97′) generating a speed command signal instructing the rotation speed of a reel having said magnetic tape wound therearound; an arithmetic circuit (98) computing the phase difference between said speed command signal and said tape tension signal thereby generating a phase difference signal; and a tape reel driver (99) generating, in response to said phase difference signal, a drive signal for driving said tape reel.

Claim 6

A digital video signal reproducing apparatus including a capstan (8) for driving a magnetic tape (2) and a drum (1) having a plurality of magnetic heads (PB1 to PB4) for scanning tracks of said magnetic tape, said capstan and said drum being driven at a non-standard speed so as to reproduce and store data, recorded on said magnetic tape, in a memory and to carry out compression and expansion of the recorded data in reproduction, said apparatus comprising: a servo unit (14) driving said capstan (8) and said drum (1), said servo unit including: phase detecting means (83, 13, 87, 82) for comparing a signal indicative of the rotation speed of said drum with a predetermined reference signal thereby detecting the phase difference therebetween; frequency discriminating means (80) for discriminating the frequency of said drum rotation speed signal on the basis of a target value based on a command signal instructing the rotation speed of said drum; drum drive means (85) generating a drum drive signal driving said drum on the basis of the detected phase difference and the result of frequency discrimina­tion, said drum drive signal being changed at a predeter­mined time interval in response to a change in said target value; first error computing means (93, 80′) discrimi­nating the frequency of a signal indicative of the rotation speed of said capstan on the basis of a target value based on a command signal instructing the rotation speed of said capstan thereby computing the phase difference between said capstan rotation speed signal and said target value; second error computing means (13, 87, 88, 89) delaying said drum rotation reference signal according to said capstan rotation speed signal thereby generating a delayed reference signal and computing the phase difference between said delayed reference signal and a predetermined control signal recorded on said magnetic tape; and capstan drive means (91) for generating a capstan drive signal driving said capstan on the basis of the phase differences computed by said first error computing means and said second error computing means respectively, the amount of delay of said delayed reference signal being changed according to said capstan rotation speed command signal.

Claim 7

A digital video signal reproducing apparatus including a capstan (8) for driving a magnetic tape (2) and a drum (1) having a plurality of magnetic heads (PB1 to PB4) for scanning tracks of said magnetic tape, said capstan and said drum being driven at a non-standard speed so as to reproduce and store data, recorded on said magnetic tape, in a memory and to carry out compression and expansion of the recorded data in reproduction, said apparatus comprising: a servo unit (14) driving said capstan (8) and said drum (1), said servo unit including: phase detecting means (83, 13, 87, 82) for comparing a signal indicative of the rotation speed of said drum with a predetermined reference signal thereby detecting the phase difference therebetween; frequency discriminating means (80) for discriminating the frequency of said drum rotation speed signal on the basis of a target value based on a command signal instructing the rotation speed of said drum; drum drive means (85) generating a drum drive signal driving said drum on the basis of the detected phase difference and the result of frequency discrimina­tion, said drum drive signal being changed at a predeter­mined time interval in response to a change in said target value; first error computing means (93, 80′) discrimi­nating the frequency of a signal indicative of the rotation speed of said capstan on the basis of a target value based on a command signal instructing the rotation speed of said capstan thereby computing the phase difference between said capstan rotation speed signal and said target value; second error computing means (13, 87, 88, 89) delaying said drum rotation reference signal according to said capstan rotation speed signal thereby generating a delayed reference signal and computing the phase difference between said delayed reference signal and a predetermined control signal recorded on said magnetic tape; and capstan drive means (91) for generating a capstan drive signal driving said capstan on the basis of the phase differences computed by said first error computing means and said second error computing means respectively, the amount of delay of said delayed reference signal being changed according to said capstan rotation speed command signal.

Claim 8

A digital video signal reproducing apparatus including a capstan (8) for driving a magnetic tape (2) and a drum (1) having a plurality of magnetic heads (PB1 to PB4) for scanning tracks of said magnetic tape, said capstan and said drum being driven at a non-standard speed so as to reproduce and store data, recorded on said magnetic tape, in a memory and to carry out compression and expansion of the recorded data in reproduction, said apparatus comprising: system control means (16) for generating command signals instructing the rotation speeds of said drum and said capstan; pitch control means (77) for controlling the tone pitch of the audio output signal; and interface means (17, 76) disposed between said system control means and said pitch control means for controlling the tone pitch of said audio output signal according to said capstan rotation speed command signal.

Claim 9

A digital video signal reproducing apparatus including a capstan (8) for driving a magnetic tape (2) and a drum (1) having a plurality of magnetic heads (PB1 to PB4) for scanning tracks of said magnetic tape, said capstan and said drum being driven at a non-standard speed so as to reproduce and store data, recorded on said magnetic tape, in a memory and to carry out compression and expansion of the recorded data in reproduction, said apparatus comprising: system control means (16) for generating command signals instructing the rotation speeds of said drum and said capstan; pitch control means (77) for controlling the tone pitch of the audio output signal; and interface means (17, 76) disposed between said system control means and said pitch control means for controlling the tone pitch of said audio output signal according to said capstan rotation speed command signal.

Claim 10

A digital video signal reproducing apparatus according to Claim 5, wherein said rotation speed command signal is a relative speed signal generated from a rela­tive speed detecting circuit (86) on the basis of a relative speed which is the vector sum of the moving speed of said magnetic tape and the rotation speed of said drum.