JPH0575965A - Magnetic recording / reproducing device - Google Patents

Abstract

(57) [Abstract] [Purpose] When reproducing the video signal recorded on the magnetic tape by repeating the still reproduction and the normal reproduction, the normal reproduction feed can be switched from the still reproduction by detecting the recording mode of the magnetic tape. Optimal control of speed. When reproducing a video signal recorded on a video track 2 at a preset interval density according to a recording mode on a magnetic tape 1 through a first magnetic head moving along the track of the video track 2. , A capstan motor control circuit 5 for moving or stopping the magnetic tape 1 in the longitudinal direction, a microcomputer 8 and a control head driving device 25 when the capstan motor 4 is stopping the magnetic tape 1. By moving the second control head 6 along the control track 28, a signal corresponding to the recording mode of the video signal is obtained from the control track 28 of the magnetic tape 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing apparatus, and more particularly, in a helical scan type video tape recorder, a magnetic tape in which a recording portion in a standard time recording mode and a recording portion in a long time recording mode coexist is thrown or stilled. The present invention relates to a magnetic recording / reproducing apparatus suitable for reducing noise accompanying switching of recording modes in special reproduction such as.

[0002]

2. Description of the Related Art FIG. 3 is a schematic block diagram of a conventional magnetic recording / reproducing apparatus. In the figure, 1 is a magnetic tape for recording video signals, audio signals, etc., 2 is a magnetic tape 1 on the tape longitudinal direction. A video track formed diagonally with respect to which video signals and hi-fi audio signals are written, 3
Is a magnetic tape running control signal written in a control track 28 formed on the magnetic tape 1 in the tape longitudinal direction, 4 is a capstan motor for running the magnetic tape 1 in its longitudinal direction, and 9 is a capstan motor 4 A frequency generator 5 for generating a signal having a frequency corresponding to the rotation speed according to the rotation, a capstan motor control circuit 5 for controlling the rotation of the capstan motor 4, and a reference numeral 6 for reading the magnetic tape running control signal 3 from the control track 28. For controlling the magnetic tape, 24 is a control signal amplifier for amplifying the magnetic tape running control signal 3 read by the control head 6, and 7 is a control signal amplifier 2.
4. A capstan motor phase comparator 31 and a frequency generator 9 for phase-comparing the magnetic tape running control signal 3 from 4 with a reference.
A capstan servo that outputs a servo control signal of the capstan motor 4 to the capstan motor control circuit 5 and is composed of a capstan motor frequency comparator 32 that compares the frequency from the reference frequency with a reference and a mixing filter 33 that mixes respective outputs. Reference numeral 10 denotes a rotary video head attached to a rotary drum 34 for forming a video track 2 on a magnetic tape 1 and recording / reproducing a video signal.
Is a drum motor for rotating the rotary video head 10 together with the rotary drum 34, 12 is a drum motor control circuit for controlling the drum motor 11, 13 is a magnet piece attached to the rotary drum 34, and 14 is a magnet piece 13 A fixed detection head for detecting the rotation phase of the rotary video head 10 accompanying the rotation of the rotary drum 34;
Is a drum motor frequency generator that generates a signal having a frequency corresponding to the rotation speed of the drum motor 11, 3
A video signal amplifier 5 amplifies the video signal read from the video track 2 by the rotary video head 10.
6 is a changeover switch for generating a changeover signal for the rotary video head 10 from the rotation phase signal from the fixed detection head 14 and giving it to the video signal amplifier 35, and a drum motor phase comparator 37 for comparing the phase of this changeover signal with a reference and a drum motor frequency. The drum motor frequency comparator 38, which compares the frequency signal from the generator 16 with the reference frequency, and the mixing filter 39, which mixes the respective outputs, transmits the servo control signal of the drum motor 11 to the drum motor control circuit 12.
And a drum servo control circuit 8 for outputting the magnetic tape running control signal from the control signal amplifier 24 and a switching signal from the switching switch 15 to the arithmetic unit 4
The capstan motor drive stop control voltage is generated based on 0 and the output of the arithmetic unit 40, and the capstan motor control circuit 5 is generated.
It is a microcomputer including a capstan motor drive stop control circuit 41 for outputting to.

The operation of the above arrangement will be described below.

During normal operation, the capstan motor 4 feeds the magnetic tape 1 at a constant number of revolutions at a constant speed, during which a video signal from the video track 2 on the magnetic tape 1 is driven by the rotating video head 10 rotating at a constant speed. Is reproduced and taken out through the video signal amplifier 35.
In this case, the feeding speed of the magnetic tape 1 reads the magnetic tape running control signal 3 recorded on the control track 28 from the control head 6 through the control signal amplifier 24, while detecting the rotation speed of the capstan motor 4 through the frequency generator 9. Then, a servo control signal is generated by applying these signals to the capstan servo circuit 7, and is applied to the capstan motor control circuit 5 for control. On the other hand, rotating video head 1
The rotation speed of 0 is detected by the fixed detection head 14 of the magnet piece 13 rotating with the rotating drum 34, while the rotation speed of the drum motor 11 is detected by the drum motor frequency generator 16, and these signals are detected by the drum servo control circuit 36. To generate a servo control signal, which is applied to the drum motor control circuit 12 for control. By the way, the rotary drum 34 is provided with a plurality of rotary video heads 10. The heads are switched by applying a signal from the fixed detection head 14 to the video signal amplifier 35 through the changeover switch 15.

In addition to the normal operation as described above, there is special reproduction called still reproduction or slow reproduction. In this still reproduction, the movement of the capstan motor 4 is completely stopped and the video track 2 on the magnetic tape 1 is repeatedly reproduced by the rotary video head 10 over the same one track or a plurality of tracks.
It is possible to reproduce still picture images extracted from the moving picture images continuously recorded on the video track 2 of FIG. It is possible to switch to another still screen by finely feeding and returning the magnetic tape 1 by the capstan motor 4 during the still reproduction. On the other hand, in the slow reproduction, the still reproduction is performed while the magnetic tape 1 is intermittently fed at a desired time interval, so that moving picture images continuously recorded on the magnetic tape 1 are reproduced as slow motion. The capstan motor 4 is controlled in the special reproduction by controlling the capstan motor drive stop control voltage 4 of the microcomputer 8.
To 1.

FIG. 4 is a timing chart for explaining the slow reproduction operation. FIG. 4A shows a video head switching signal 18 obtained from the fixed detection head 14 through the changeover switch 15, and FIG. Is a capstan motor control voltage 17 applied from the capstan motor drive stop control circuit 41 to the capstan motor 4 through the capstan motor control circuit 5, and FIG. 7C is recorded on the control track 28 and reproduced from the control head 6. The control signals 19 are shown respectively. On the other hand, the period 20 is a period during which the capstan motor 4 is controlled by the capstan servo circuit 7,
A period 21 is a period in which the capstan motor 4 is controlled by the microcomputer 8, a period 22 is a period during still reproduction, and a period 23 is a period from the rising of the control signal 19 to the output of the operation stop voltage of the capstan motor 4, that is, a slow period. It corresponds to a time called a tracking value.

As described above, during the slow reproduction, the still picture reproduction and the normal reproduction are repeated, and as a result, the slow motion reproduction is possible. Each of the capstan motor control voltages 17 shown in FIG. The timing is calculated by the calculator 40 of the microcomputer 8 and output from the capstan motor drive stop control circuit 41.

Incidentally, a video tape recorder, which is a general magnetic recording / reproducing apparatus, can generally select either a standard mode or a long-time recording mode. In the long-time recording mode, the standard recording mode can be selected. 1/3 of the running speed of the magnetic tape 1 by the capstan motor 4 compared to
The recording time is tripled by lowering the distance between the video tracks 2 and increasing the density of the video tracks 2 to 1/3.
In this case, the control track 28 on the magnetic tape 1
The recording interval of the magnetic tape running control signal 3 recorded in 1 is also shortened to 1/3 as compared with the standard time. Therefore, at the time of reproduction, the traveling speed of the magnetic tape 1 is switched by determining the servo control signal to be given to the capstan motor 4 based on the magnetic tape traveling control signal 3 from the control track 28, and the standard mode or the long time mode is selected. Playback can be switched. Which mode the reproducing mode is can be known by giving the magnetic tape running control signal 3 obtained by the control head 6 to the microcomputer 8.

In the slow reproduction, the still reproduction in which the movement of the capstan motor 4 is completely stopped and the normal reproduction in which the capstan motor 4 is sent at the normal speed are appropriately switched according to the speed of the slow reproduction. The traveling speed in the period 20 of 4 is determined based on the normal reproduction mode, that is, the standard reproduction mode or the long-time reproduction mode. In other words, when the normal playback is the standard playback mode, the normal playback that is switched from the still playback that is the slow playback is the standard playback mode, and when the normal playback is the long playback mode, the normal playback that is switched from the still playback that is the slow playback is the normal playback The long-time playback mode is set. The mode during normal reproduction is stored in the microcomputer 8 in advance based on the magnetic tape running control signal 3 obtained from the control head 6 through the control signal amplifier 24 during normal reproduction.
The traveling speed of 0 is determined and controlled by the capstan motor drive stop control circuit 41 according to the mode recorded in the microcomputer 8. In addition, since switching to another still screen by feed / return in still playback also shifts through normal playback in exactly the same way as in slow playback, the pitch of feed / return is the recording mode during normal playback. Determined by

[0010]

Since the conventional magnetic recording / reproducing apparatus is constructed as described above, the recording mode of the video signal recorded on the magnetic tape 1 is either standard or long time. If it is fixed to the mode, the slow play and still play screens can be sent and returned without problems, but the standard record mode and the long record mode images are recorded in a mixed manner, and the slow play and still play screens are recorded. If the recording mode is switched during the sending or returning of, the microcomputer 8 cannot determine the change, and there is a problem that noise is increased and clear reproduction cannot be performed.

The present invention has been made to solve the above-mentioned problems, and when a video signal recorded on a magnetic tape is reproduced by repeating still reproduction and normal reproduction, a recording mode of the magnetic tape is used. Of the magnetic tape that can be switched from the still reproduction to the optimum speed of the normal reproduction to improve the image quality when performing special reproduction such as slow or still on a magnetic tape with mixed recording modes. It is intended to provide a recording / reproducing device.

[0012]

In order to achieve the above object, a magnetic recording / reproducing apparatus according to a first aspect of the present invention is characterized in that a video signal is recorded at a preset interval according to a recording mode.
Second track group and a second track group in which a control signal corresponding to the recording mode of the video signal recorded in the first track group is recorded.
A magnetic tape on which tracks are set, running control means for running or stopping the magnetic tape in the longitudinal direction thereof, and a first for reproducing a video signal while moving along the track direction of the first track group. A magnetic head, a second magnetic head for reproducing a control signal from the second track, and a movement control means for moving the second magnetic head along the second track. .. In order to achieve the above object, in the magnetic recording / reproducing apparatus according to claim 2, the movement control means causes the second magnetic head to move when the running control means stops the feeding of the magnetic tape. It is characterized in that the control signal is read by moving along the second track of the magnetic tape.

Further, in order to achieve the above object, in the magnetic recording / reproducing apparatus according to a third aspect of the present invention, when the running control means stops the feeding of the magnetic tape, the second magnetic control means is operated through the movement control means. The head is the second part of the magnetic tape.
And a control means for determining the recording mode of the video signal recorded on the first track group of the magnetic tape by moving the track along the track to read the control signal.

Further, in order to achieve the above object, in the magnetic recording / reproducing apparatus according to a fourth aspect of the present invention, the first track is repeated while the running control means stops the feeding of the magnetic tape or repeats the normal feeding operation. When reproducing the video signal from the group through the first magnetic head, the movement control means moves the second magnetic head along the second track of the magnetic tape when the feeding of the magnetic tape is stopped. It is characterized in that the feeding speed of the magnetic tape during the normal feeding operation is determined.

[0015]

In the above means, in the magnetic recording / reproducing apparatus of the present invention, the video signal recorded on the first track group at the interval density preset according to the recording mode on the magnetic tape is recorded on the first track group. First to move along the track
When the reproduction control means for moving or stopping the magnetic tape in its longitudinal direction is stopping the magnetic tape when reproducing through the magnetic head, the moving means moves the second magnetic head to the second track. A signal corresponding to the recording mode of the video signal is obtained from the second track of the magnetic tape by moving the magnetic tape.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic block diagram of a magnetic recording / reproducing apparatus according to an embodiment of the present invention. In FIG. 1, reference numeral 25 indicates a control head 6 on a control track 28 based on a command from a microcomputer 8 during slow reproduction. It is a control head driving device for moving along arrow 29 and arrow 30.

The operation of the above arrangement will be described with reference to the timing chart of FIG. Incidentally, FIG. 2 shows changes in the capstan motor control voltage 17.

In a normal reproducing operation, the capstan motor 4 feeds the magnetic tape 1 at a constant rotational speed at a constant speed, during which the video track on the magnetic tape 1 is transferred in the same manner as in the configuration shown in FIG. The video signal from 2 is reproduced. In this case, as for the feeding speed of the magnetic tape 1 by the capstan motor 4, the magnetic tape running control signal 3 recorded on the control track 28 is read from the control head 6 through the control signal amplifier 24, while the rotation speed of the capstan motor 4 is changed to the frequency. The servo control signal is detected by the generator 9 and is applied to the capstan servo circuit 7 to generate a servo control signal, which is applied to the capstan motor control circuit 5 for control.

In addition to the above normal operation, the case of special reproduction called still reproduction or slow reproduction will be described. In the case of still reproduction, the movement of the capstan motor 4 is stopped at all, and the video track 2 on the magnetic tape 1 is repeatedly reproduced over the same one track or a plurality of tracks. The still image image extracted from the continuously recorded moving image image is reproduced, but in this case, the control signal is given from the microcomputer 8 to the control head driving device 25 so that the control head 6 is moved on the magnetic tape 1. Arrow 2 along the control track 28
9 or move in the direction of arrow 30. As a result, since the magnetic tape running control signal 3 on the control track 28 is reproduced from the control head 6, the microcomputer 8 supplied with the magnetic tape running control signal 3 through the control signal amplifier 24 causes the video signal on the video track 2 to be supplied to the microcomputer 8. It is possible to discriminate the recording mode, that is, the standard mode or the long time mode. As a result, it is possible to determine the feed or return speed of the magnetic tape 1 by the capstan motor 4 when shifting to another still screen at the time of still reproduction according to the recording mode. By the way, the recording mode is determined by determining the pulse number of the magnetic tape running control signal 3 obtained when the control head 6 is moved a fixed distance by the microcomputer 8.

On the other hand, during slow reproduction in which moving picture images continuously recorded on the magnetic tape 1 are reproduced as slow motion, the above still reproduction and normal reproduction are alternately switched at appropriate time intervals. In this case, Is shown in FIG.
As shown in the timing chart of FIG. 3, the microcomputer 8 controls the drive of the capstan motor 4 through the capstan motor control circuit 5 in the period 20 and the stop control in the period 22. When the feeding of the magnetic tape 1 in the period 22 is stopped, a control signal is given from the microcomputer 8 to the control head driving device 25 so that the control head 6 is moved along the control track 28 on the magnetic tape 1 by the arrow 29 or the arrow 30. Move in the direction. As a result, the magnetic tape running control signal 3 on the control track 28 is sent from the control head 6.
Is reproduced, the microcomputer 8 to which the magnetic tape running control signal 3 is applied through the control signal amplifier 24 can determine the recording mode of the video signal on the video track 2, that is, the standard mode or the long time mode. As a result, in the next period 20, it is possible to determine the feeding speed when the magnetic tape 1 is fed by the capstan motor 4 and the normal reproduction is performed according to the recording mode.

As a result of the above control, even if the recording mode is switched while the magnetic tape 1 is being sent or returned during special reproduction such as still reproduction or slow reproduction, the control head drive device 25 causes Since the magnetic tape running control signal 3 can be reproduced from the control track 28 via the control head 6 which is moved, the microcomputer 8 can determine the recording mode on the magnetic tape 1, and the magnetic field can be detected by the capstan motor 4. The speed at which the tape 1 is fed or returned can be determined according to the recording mode.

The determination of the recording mode can be easily realized by counting the pulse number of the magnetic tape running control signal 3 obtained when the control head 6 is moved by a certain distance by the microcomputer 8, but the magnetic tape running control is performed. Even a system in which a code signal is recorded as the signal 3 can be realized by reading the code by the microcomputer 8.

In the above embodiment, the control head 6 is moved to determine the recording mode when determining the recording mode of the video signal recorded on the magnetic tape during special reproduction such as still or slow. By setting the magnetic tape 1 in the magnetic recording / reproducing apparatus and moving the control head 6 at the time of loading, the recording / non-recording of the signal to / from the magnetic tape 1 based on the presence / absence of recording of the magnetic tape running control signal 3 and the number of pulses. It is possible to determine the recording state and the recording mode before the magnetic tape 1 is run.

[0025]

As described above, according to the present invention, in the helical scan type video tape recorder, the magnetic head running on the control track is moved by moving the control head even when the feeding of the magnetic tape is stopped. Since the control signal can be read, even if the recording mode of the video signal is switched during the forward / backward movement of the screen during still playback and slow playback, the recording mode can be discriminated by the signal from the control head. The speed can be optimally controlled, and a clear special playback image can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a magnetic recording / reproducing apparatus according to an embodiment of the present invention.

FIG. 2 is a timing chart for explaining the operation of the configuration of FIG.

FIG. 3 is a schematic configuration diagram of a conventional magnetic recording / reproducing apparatus.

FIG. 4 is a timing chart for explaining the operation of the configuration of FIG.

[Explanation of symbols]

 1 magnetic tape 2 video track 3 magnetic tape running control signal 4 capstan motor 5 capstan motor control circuit 6 control head 7 capstan servo circuit 8 microcomputer 9 frequency generator 10 rotating video head 11 drum motor 12 drum motor control circuit 13 Magnet piece 14 Fixed detection head 15 Changeover switch 16 Drum motor frequency generator 24 Control signal amplifier 25 Control head driver 28 Control track 31 Capstan motor phase comparator 32 Capstan motor frequency comparator 33 Mixing filter 34 Rotating drum 35 Video signal Amplifier 36 Drum Servo Control Circuit 37 Drum Motor Phase Comparator 38 Drum Motor Frequency Comparator 39 Mixing Filter 40 Computing Unit 41 Yapusutanmota drive stop control circuit

Claims (4)

[Claims] 1. A first track group in which video signals are recorded at preset intervals according to the recording mode, and a control signal corresponding to the recording mode of the video signals in the first track group is recorded. A magnetic tape on which a second track is set, running control means for running or stopping the magnetic tape in the longitudinal direction thereof, and reproducing a video signal while moving along the track direction of the first track group. A first magnetic head, a second magnetic head that reproduces a control signal from the second track, and a movement control unit that moves the second magnetic head along the second track. A magnetic recording / reproducing apparatus characterized by the above. 2. The magnetic recording / reproducing apparatus according to claim 1, wherein the movement control means causes the second magnetic head to move to the second side of the magnetic tape when the running control means stops the feeding of the magnetic tape. A magnetic recording / reproducing apparatus characterized in that the control signal is read out by moving along the track. 3. The magnetic recording / reproducing apparatus according to claim 1, wherein when the running control means stops the feeding of the magnetic tape, the movement control means causes the second magnetic head to move to the second position of the magnetic tape. Magnetic recording / reproducing, characterized by comprising control means for discriminating the recording mode of the video signal recorded on the first track group of the magnetic tape by moving it along the track to read the control signal. apparatus. 4. The magnetic recording / reproducing apparatus according to claim 1, wherein the running control means repeats the operation of stopping the feeding of the magnetic tape or normally feeding the magnetic tape, and then the first magnetic head from the first track group. When reproducing the video signal through the magnetic tape, the movement control means moves the second magnetic head along the second track of the magnetic tape when the magnetic tape is stopped to feed the magnetic tape during the normal feeding operation. A magnetic recording / reproducing apparatus characterized by determining a tape feeding speed.