JPH0683424B2 - Magnetic tape video playback device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a VTR (video tape recorder), which is a 5x speed recorder for a VTR using an azimuth recording method.
The present invention relates to a magnetic tape video reproducing apparatus suitable for reproducing a multiple speed image such as a double speed.

[Conventional technology]

Conventionally, a method of reducing noise in multiple speed reproduction is, for example,
It is disclosed in Japanese Patent Application Laid-Open No. 56-162578.

FIG. 6 is a schematic diagram of a head locus at the time of reproducing a multiple speed image in the conventional magnetic recording / reproducing apparatus shown in the above publication.
In FIG. 6, 2 is a magnetic tape, and the dotted line is-
The locus of a magnetic head at 7 times speed, a and b indicate tracks with different azimuths.

The conventional arrangement of magnetic heads is as shown in FIG. 7 (a), and in addition to the first and second magnetic heads A and B having different azimuth angles, both magnetic heads A and B are provided in the rotary cylinder 1. Third and fourth magnetic heads A1 and B1 are arranged in the same rotation plane and in the vicinity of both magnetic heads A and B, respectively.

Further, as shown in FIG. 7B, the first magnetic head A
The azimuth angle of the third magnetic head A1 arranged near the first magnetic head B1 is the same as that of the second magnetic head B, and the azimuth angle of the fourth magnetic head B1 arranged near the second magnetic head B is the first. It is the same as the magnetic head A.

At the time of storage, while the magnetic tape 2 is running at a predetermined speed, of the magnetic heads, the first and second magnetic heads A,
By B, the field signals are sequentially recorded on the tape as recording tracks.

When the magnetic tape 2 is transported at the same speed as when it is rewound and high speed reproduction in the reverse direction is performed, the first to fourth magnetic heads A,
B, A1, and B1 are sequentially scanned over the recording tracks on the magnetic tape 2 to obtain a reproduction output.

In this case, the scanning locus of the magnetic head is as shown in FIG. First, the first magnetic head A and the third magnetic head A1 arranged close to the first magnetic head A and having different azimuth angles travel sequentially from the lower right to the upper left of the magnetic tape 2 across the recording tracks.

At this time, the outputs of the first magnetic head A and the third magnetic head A1 are as shown by the solid line and the broken line in FIG. 7 (c).

That is, when the first magnetic head A moves from the track a to the track b and the head output starts to decrease due to azimuth loss, the head output of the third magnetic head A1 starts to increase.

As a result, the output of either one of the two magnetic heads is always above a certain level. Therefore, the output of both magnetic heads can be
By switching near the point where the outputs of both magnetic heads are at the same level, as shown in FIG. 7 (d), the output level slightly drops near the head switching point, but there is no portion where it becomes 0, and the output level is above a certain level. Continuous reproduction output can be obtained.

When both the magnetic heads A and A1 scan up to the upper left of the magnetic tape 2 and then the second and fourth magnetic heads B and B1 start scanning, reproduction output is obtained in the same manner as described above. By combining the outputs, a continuous playback video output without interruption can be obtained.

Next, the operation of the magnetic recording / reproducing apparatus will be described with reference to FIG. First, at the time of recording, the first and second magnetic heads A and A1 are respectively connected to the recording amplifier 3, and the video signal amplified by the recording amplifier 3 is supplied to both magnetic heads A and B to be recorded on the magnetic tape. Record.

During reproduction, that is, during reproduction of a multi-speed image, the first to fourth magnetic heads A, B, A1 and B1 are connected to the first to fourth preamplifiers 4,5, 6 and 7, respectively. Each of these preamplifiers 4-7
, Has a built-in switcher (not shown).
It is controlled by the Q and output of the second head switching pulse generation circuits 8 and 9, respectively.

Next, the first head switching pulse generating circuit 8 will be described with reference to the waveform chart of each part in FIG. The output of the third preamplifier 6,
That is, the output c (FIG. 9 (A)) obtained by scanning the track b of the third magnetic head A1 is output d (9th output) obtained by detecting the envelope by the first envelope detection circuit 81.
The first waveform shaping circuit 82 in FIG.
For example, the waveform is shaped into a pulse e (Fig. 9 (C)) that becomes high at 50% or more of the maximum level and becomes low at less than 50%, and the Q output is output from the first flip-flop 83 (Fig. 9 (D). ))
And output g (FIG. 9 (E)) are obtained.

These outputs are used as head switching pulses to control the outputs of the first and third preamplifiers 4 and 6, respectively.

Similarly, the output of the envelope detection circuit 91 of the second head switching pulse generation circuit 9 is waveform-shaped by the waveform shaping circuit 92, and the Q output and the output of the flip-flop 93 are used to output the second and fourth preamplifiers 5, Control the output of 7.

Therefore, the output of any one of the first to fourth preamplifiers 4 to 7 is sequentially supplied to the fifth preamplifier 10 and amplified.

The output of the fifth preamplifier 10 is converted into a video signal by the FM demodulator 121.

When reproducing multiple speed images such as high-speed reproduction by the above method, the output of two adjacent magnetic heads with different azimuth angles is selected and the head output is switched, so the reproduction output is significantly reduced. There is nothing to do.

[Problems to be solved by the invention]

However, since noise is generated at the switching point of the output of the preamplifier and the image content of another track changes, the image content does not match and there is a problem that a divided and combined screen is displayed.

The present invention has been made in order to solve the above problems, noise at the output switching point of the preamplifier is eliminated, the contents of another track are not changed, and the image becomes a divided and combined screen. It is an object of the present invention to obtain a magnetic tape image reproducing device that can obtain a good screen without a problem.

[Means for solving problems]

The present invention is a video signal reproducing device for reproducing a video signal recorded on a recording track of a magnetic tape, wherein the rotary cylinder and the rotation center of the rotary cylinder are at respective angular positions of 180 degrees. A plurality of fixed magnetic heads to be provided and the rotation center of the rotary cylinder, each of which is at an angular position of 180 degrees with respect to each other, are provided at positions different from the fixed magnetic head, and A plurality of movable magnetic heads whose positions can be controlled in the width direction, tape drive means for causing the magnetic tape to travel on the peripheral surface of the rotating cylinder at a predetermined speed, and the predetermined running speed of the magnetic tape to be the same as during recording. The speed setting means for giving a command to the tape driving means to set the speed to 1 or an arbitrary second speed different from that at the time of recording, and the magnetic tape to the second speed. When traveling at a speed, position control means for controlling the position of the movable magnetic head in the track width direction so that the movable magnetic head traces the recording track of the magnetic tape, and a reproduction signal from the movable magnetic head Envelope detection, displacement voltage generating means for outputting a displacement voltage for position control of the movable magnetic head based on a hill climbing control signal for controlling the detection signal to be maximum, and a recording track on a magnetic tape. A plurality of adding means for supplying to the position control means a sum signal of a synchronizing signal for matching the inclinations of the loci of the movable magnetic head and an output from the displacement voltage generating means, a reproduction signal from the fixed magnetic head and the above Switching means for selecting one of the reproduction signals from the movable magnetic head, and a decoding means for demodulating the output signal selected by the switching means. And the traveling speed of the magnetic tape is set to the first speed, the switching means outputs the reproduction signal from the fixed magnetic head, and the traveling speed of the magnetic tape is the second speed. When the traveling speed of the magnetic tape reaches the second speed, a signal for activating the displacement voltage generating means and a hill climbing speed increasing signal for increasing the output of the displacement voltage generating means are output. Then, until the time when the movable magnetic head is on-track to the recording track elapses, the switching means outputs the reproduction signal from the fixed magnetic head, and the time when the movable magnetic head is on-track to the recording track elapses. After that, it is configured to include a control means for stopping the hill-climbing speed-up signal and causing the switching means to output a reproduction signal by the movable magnetic head.

[Action]

The present invention, while running at an arbitrary speed different from the time of recording,
The output of the displacement voltage generating means is increased to control the movable magnetic head until the time when the movable magnetic head is on-track on the recording track elapses, and during that time, the reproduction signal from the fixed magnetic head is output to the switching means. Then, after the time when the movable magnetic head is on-track to the recording track,
The reproduction signal from the movable magnetic head is output to the switching means.

〔Example〕

An embodiment of a magnetic tape image reproducing apparatus of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the construction of one embodiment thereof. Prior to the explanation of FIG. 1, the arrangement row of magnetic heads applied to the present invention will be explained first with reference to FIG.

In FIG. 2, the same parts as those in FIG. 8 are designated by the same reference numerals. In addition to the first and second magnetic heads A and B, which have different azimuth angles, the rotary cylinder 1
Third and fourth magnetic heads A1 and B1 are arranged near the first and second magnetic heads A and B, respectively.

The azimuth angle of the third magnetic head A1 arranged in the vicinity of the first magnetic head A is the same as that of the second magnetic head B, and the fourth magnetic head arranged in the vicinity of the second magnetic head B. The azimuth angle of B1 is the same as that of the first magnetic head A.

Further, D and E are fifth and sixth magnetic heads, respectively, which control the position of the magnetic tape 2 in the width direction of the recording track.
It is attached to the tips of the actuators 11 and 12 of
The rotary cylinder 1 is arranged at an angle position of 180 degrees with respect to the center of rotation.

The first and second actuators 11 and 12 are, for example, Japanese Patent Laid-Open No. 58-809.
As disclosed in Japanese Patent Laid-Open No. 80, which is based on an electro-mechanical conversion element, the first and second actuators 11,1
The second and fifth magnetic heads D and E are attached to 2, respectively.

A drive signal is applied to the first and second actuators 11 and 12, and the drive signal and the reproduction envelopes of the fifth and sixth magnetic heads D and E are used to detect the fifth and sixth magnetic heads for the recording track. It knows the position and goes on track.

Next, an embodiment of the present invention shown in FIG. 1 will be described. First
The first and second magnetic heads A and B are connected to the output terminal of the recording amplifier 3 via the rotary transformer R during recording,
At the time of reproduction, the rotary transformer R is connected to the input terminals of the first and second preamplifiers 4 and 5.

The third and fourth magnetic heads A1 and B1 are connected to the input ends of the third and fourth preamplifiers 6 and 7 via the rotary transformer R. The output terminals of these first to fourth preamplifiers 4 to 7 are connected to the input terminals of the preamplifier 10. Preamp 10
The output terminal of is connected to the AB terminal of the switch 120.

Reference numerals 8 and 9 denote first and second head switching pulse generation circuits, respectively, and the first head switching pulse generation circuit 8 obtains the output of the third preamplifier 6, that is, the track scanning of the third magnetic head A1. The output c thus obtained is detected by the first envelope detection circuit 81, the output d thereof is waveform-shaped by the waveform shaping circuit 82, the flip-flop 83 is activated by the output e thereof, and the Q output f is outputted by the first preamplifier 4 The output g is added to the third preamplifier 6 as well.

The outputs f and g control the outputs of the first and third preamplifiers 4 and 6.

Similarly, the second head switching pulse generation circuit 9 also has an envelope detection circuit 91, a waveform shaping circuit 92, and a flip-flop.
Q flip-flop 93 Q output,
Add the output to the 2nd and 4th preamplifiers 5 and 7, respectively.
The output of the second and fourth preamplifiers 5 and 7 is controlled.

On the other hand, the output signals of the fifth and sixth magnetic heads D and E are supplied to the preamplifiers 104 and 114 via the rotary transformer R. The outputs of the preamplifiers 104 and 114 are supplied to the DE terminals of the envelope detection circuit 118 and the switch 120 via the switch 115 for switching the video head.

The output signal of the rotation detector 117 is a waveform shaping circuit in the switch 115.
It is driven by a video switching signal J (described later) processed in 116.

The output signal of the envelope detection circuit 118 is supplied to the displacement voltage generators 103 and 113. The output signals of the displacement voltage generators 103 and 113 are adders 101 and 111, respectively.
I am trying to add it to.

The outputs of the synchronization signal generators 102 and 112 are added to the adders 101 and 111, respectively, and the adders 101 and 111 add the output signals of the synchronization signal generators 102 and 112 and the output signals of the displacement voltage generators 103 and 113, respectively. , The addition result is supplied to the first and second actuators 11 and 12 via the slip ring S, and the first and second actuators 11 and 12 are supplied.
I am trying to drive.

Further, the displacement voltage generators 103 and 113 are sequence signal generators 124.
The output voltage generation signal G controls the generation of output signals, and the voltage of each output signal is controlled so that the output of the envelope detection circuit 118 becomes maximum in response to the video switching signal. "Mountain climbing control" is designed.

Further, the tape speedup signal F is output from the sequence signal generator 124, and the switching signal H is applied to the switch 120 to switch the AB end. In addition, the hill climbing speedup signal I is supplied to the displacement voltage generator 103 in order to perform the "hill climbing control".

The reproduced signals of the fifth and sixth magnetic heads D and E are added from the switch 120 to the demodulation circuit 121, and the video signal is taken out from the demodulation circuit 121. Note that 125 is the sequence signal generator 1
A switch connected between 24 and ground.

The internal structure of the displacement voltage generator 103 is shown in FIG. As is apparent from FIG. 3, the envelope detection output signal L from the envelope detection circuit 118 is input to the comparison circuit 1032 and the storage circuit 1033.

The video head switching signal J is input to the delay circuit 1031 and the comparison timing signal K delayed by 270 degrees from the delay circuit 1031 is added to the comparison circuit 1032 and the storage circuit 1033. At the same time, the storage timing signal K is applied to the storage circuit 1033.

The storage circuit 1033 stores the envelope detection output signal L by the storage timing signal K, and the comparison circuit 1032 compares the storage signal M of the storage circuit 1033 with the envelope detection output signal L by the comparison timing signal K, Based on the comparison result, the lift output signal P is changed to the track width direction drive circuit.
It is designed to output to 1034.

The track width direction drive circuit 1034 synchronizes with the video head switching signal J, and when the climbing speedup signal I is "0", when the elevation output signal P is "1", the displacement voltage Q is increased by a predetermined value and the elevation output is produced. Displacement voltage Q when signal P is "0"
Is reduced by a predetermined value.

Next, the operation will be described. First, at the time of recording, the first and second magnetic heads A and B are respectively connected to the recording amplifier 3, and the video signal amplified by the recording amplifier 3 is passed through the rotary transformer R to the first and second magnetic heads. It is added to A and B and recorded on tape 2.

Further, at the time of reproduction, if the speed of the tape 2 is the same as that at the time of recording, the output signals of the first magnetic head A and the second magnetic head B or the output signals of the third and fourth magnetic heads A1 and B1. Are respectively supplied to the preamplifier 10 of the next stage via the rotary transformer R, the first and second preamplifiers 4,5 or the third and fourth preamplifiers 6 and 7.

The output signal of the preamplifier 10 is led to the AB terminal of the switch 120. At this time, the switch 120 is closed to the AB end side, the output signal of the amplifier 10 is introduced into the demodulator 121, where it is demodulated and converted into a video signal.

The output signals of the fifth and sixth magnetic heads D and E are supplied to the preamplifiers 104 and 114 via the rotary transformer R.
The output signals of the preamplifiers 104 and 114 are supplied to the envelope detection circuit 118 and the DE terminal of the switch 120 via the switch 115.

On the other hand, the output signal of the rotation detector 117 undergoes waveform processing by the waveform shaping circuit 116 and becomes the video head switching signal J,
In addition to the switch 115, the switch 115 is switched.

The output signal of the preamplifier 104 or 114 passing through the switch 115 is envelope-detected by the envelope detection circuit 118, and the output signal is supplied to the displacement voltage generators 103 and 113. The details of the displacement voltage generators 103 and 113 will be described later on behalf of the displacement voltage generator 103.

The output signals of the displacement voltage generators 103 and 113 are added to the adders 101 and 111. The adders 101 and 111 add this output signal and the output signals of the synchronizing signal generators 102 and 112, and the addition result is added to the actuators 11 and 12 via the slip ring S to drive the actuators 11 and 12.

The displacement voltage generators 103 and 113 are controlled by the displacement voltage generation signal G of the sequence signal generator 124 to generate output signals.
Envelope detection circuit according to the video head switching signal
The voltage of each output signal is "climbed" so that the output of 118 is maximized. This "mountain climbing control" will be described in detail later.

The sync signal generators 102 and 112 will be described. For example, in the schematic diagram of the head locus at the multiple speed reproduction in the conventional magnetic recording / reproducing apparatus shown in FIG. 6, since the tape is fed at the speed of -7 times the reproducing speed in the -7 times reproducing, the head at this time is As shown by the dotted line, the locus on the tape further inclines relative to the tracks on the tape at a rate of 8 track pitches per field. That is, the track pitch is P, the tape speed is V, and the tape speed during playback is
When V ₀ is set, the slope is generated at a rate of P × (V−V ₀ ) / V ₀ per field.

The synchronization signal generator corrects the head locus by paying attention to the above relationship and generating a signal for displacing the head at a rate of P × (V−V ₀ ) / V ₀ per field. That is, the synchronization signal generators 102 and 112 generate signals for tracing the fifth and sixth magnetic heads D and E at the same inclination as the track on the magnetic tape 2 according to the tape speed.

Next, the operation of the sequence signal generator 124 will be described together with the time chart of FIG. When the switch 125 is closed as shown in FIG. 4 (a), the tape speed-up signal F is output from the sequence signal generator 124 as shown in FIG. By controlling the drive motor (not shown), the tape speed changes as shown in FIG. 4 (c).

Further, the displacement voltage generation signal G shown in FIG. 4 (d) is output when the speed of the magnetic tape '2 becomes stable. When this displacement voltage generation signal G is output, the displacement voltage generators 103, 113
Is activated, and the actuators 11 and 12 are controlled so that the fifth and sixth magnetic heads D and E are on-track on the recording track.

After a time sufficient for the fifth and sixth magnetic heads D and E to be on-track on the recording track, the polarity of the switching signal H of the switch 120 shown in FIG.
Is closed to the DE end side, and the output signals of the fifth and sixth magnetic heads D and E are demodulated via the preamplifiers 104 and 114 and the switch 120.
Supplied to 121.

After the tape speed-up signal F is output, the switch 120
While is closed to the DE end side, the hill-climbing speedup signal I (FIG. 4 (f)) is output.

After this hill climbing speedup signal I is output, switch 12
Until the polarity of the switching signal H of 0 changes, the outputs of the first to fourth magnetic heads A, B, A1 and B1 are supplied to the preamplifiers 4 to 7 via the rotary transformer R, as in the conventional example. To be done.

One of the outputs of the preamplifiers 4 to 7 is sequentially supplied to the preamplifier 10, amplified, and then input to the demodulator 121 via the switch 120, where it is converted into a video signal.

Next, regarding the “mountain climbing operation” of the fifth magnetic head D,
This will be described in detail with reference to FIGS. 3 and 5. The detailed internal structure of the displacement voltage generating means 103 in FIG. 1 is shown in FIG. 3, and the time chart of the hill climbing operation is shown in FIG.

The video head switching signal J is as shown in FIG.
The fifth magnetic head D is selected at the high level, and the sixth magnetic head E is selected at the low level.

Now, when the video head switching signal J is input to the delay circuit 1031, the storage and comparison timing signal K whose phase is delayed by 270 degrees is output by the delay circuit 1031 (fifth time).
Figure (b)).

In synchronization with the negative edge of the storage comparison timing signal K,
The comparison circuit 1032 outputs an envelope detection output signal L one cycle before the video head switching signal J stored in the storage circuit 1033.
(FIG. 5 (c)), that is, the storage signal M output from the storage circuit 1033 (FIG. 5 (d)) and the envelope detection output signal L in the current period are compared by the comparison circuit 1032. At the same time, the storage circuit 1033 stores the envelope detection output signal L of the current cycle in synchronization with the negative edge of the storage comparison timing signal K.

The comparison circuit 1032 compares the storage signal M of the storage circuit 1033 with the envelope detection output signal L in the current cycle,
When the envelope detection output signal L is small due to the storage signal M, the elevation output P (FIG. 5 (e)) is inverted.

On the contrary, as a result of the comparison, when the envelope detection output L is larger than the storage signal M, the ascending / descending output P is not inverted but held as it is.

The elevation output P is sent to the track width direction drive circuit 1034. The track width direction drive circuit 1034 synchronizes with the negative edge of the video head switching signal J and outputs the sequence signal generator 124.
When the hill climbing speedup signal I from is 0, the up / down output P
When the value is "1", the displacement voltage Q (Fig. 5 (f)) is increased by a predetermined value t, and when the elevation output P is "0", the displacement voltage Q is increased.
Is decreased by a predetermined value t.

Conversely, when the hill climbing speedup signal I is "1", the elevation output P
The displacement voltage Q is increased by a predetermined value s when is 1, and the voltage is decreased by a predetermined value s when the elevation output P is "0". At this time, the predetermined value s is selected to be larger than t.

This displacement voltage Q is applied to the adder 101 of FIG. 1, and the adder 101 adds this displacement voltage Q and the output signal of the synchronizing signal generator 102, and the actuator 11 through the slip ring S.
Added to. As a result, the fifth magnetic head D is displaced in the width direction of the track on the magnetic tape 2.

Since the displacement voltage generator 103 is configured in this way,
Since the track control is performed with a narrow width while the outputs of the fifth magnetic head D and the sixth magnetic head E are demodulated by the demodulation circuit 121 to become a video signal, noise is less likely to occur and the fifth magnetic head D , The output signal of the sixth magnetic head E is controlled in a wide step before demodulation, so that the envelope can be brought close to the maximum point in a short time.

〔The invention's effect〕

As described above, according to the present invention, the magnetic head is provided on the rotary cylinder provided with the fifth to sixth magnetic heads capable of position control in addition to the first to fourth magnetic heads having the same configuration as the conventional one,
During the change to an arbitrary tape speed different from that during recording,
A large one is selected from the output signals of the fourth magnetic head, demodulated and demodulated, and during this time, the fifth and sixth magnetic heads whose positions can be controlled simultaneously are used to control to trace on the recording track, and an arbitrary tape speed is set. Since it is configured to demodulate the output signals of the fifth and sixth magnetic heads, it is the same as the conventional one while the tape speed is fluctuating, but the fifth and sixth magnetic heads can be operated within a predetermined time when the tape speed is stable. The position of the magnetic head can be quickly controlled, and after a predetermined time when the tape speed has stabilized, the output signal of the fifth and sixth magnetic heads is demodulated into a video signal, and there is no noise at the output switching point of the preamplifier and another track There is an effect that a good screen can be obtained without changing the contents of the image, and the image does not become a divided and combined screen.

[Brief description of drawings]

FIG. 1 is a block diagram of a magnetic tape image reproducing apparatus according to an embodiment of the present invention, FIG. 2 is a plan view showing an example of arrangement of magnetic heads in a rotary cylinder applied to the same embodiment, and FIG. FIG. 4 is a block diagram showing the detailed internal structure of the displacement voltage generator in the embodiment, FIG. 4 is a time chart for explaining the operation of the sequence signal generator in the same embodiment, and FIG. 5 is the displacement voltage in FIG. FIG. 6 is a time chart for explaining the hill-climbing operation by the generator, FIG. 6 is a schematic diagram of a head locus at the time of reproducing a multiple speed image in a conventional magnetic recording / reproducing apparatus, and FIG. FIG. 7 (b) is an explanatory view showing the gap relation of the magnetic head of FIG. 7 (a), and FIG. 7 (c) is a conventional magnetic head. Recording / playback device FIG. 7 (d) is a schematic diagram of the trajectory of the magnetic head at the time of reproducing the multiple speed image, FIG. 7 (d) is a schematic diagram of the output of the magnetic head at the time of reproducing the multiple speed image in the conventional magnetic recording / reproducing apparatus, and FIG. FIG. 9 is a block diagram of the recording / reproducing apparatus, and FIG. 9 is a signal waveform diagram of each part of the magnetic recording / reproducing apparatus of FIG. 1 ... Rotary cylinder, 2 ... Magnetic tape, 11,12 ... Actuator, 101,111 ... Adder, 102,112 ... Synchronous signal generator, 103,113 ... Displacement voltage generator, 115,120 ... Switch, 117 ... Rotation Detector 118 ... Envelope detection circuit 121 ... Demodulator 124 ... Sequence signal generator A ...
1st magnetic head, B ... 2nd magnetic head, A1 ... 3rd magnetic head, B1 ... 4th magnetic head, D ... 5th
Magnetic head, E ... 6th magnetic head. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (2)

[Claims] 1. A video signal reproducing apparatus for reproducing a video signal recorded on a recording track of a magnetic tape, comprising: a rotary cylinder;
A plurality of fixed magnetic heads provided at an angular position of 180 degrees, and each of them is an angular position of 180 degrees with respect to the center of rotation of the rotary cylinder, and is provided at a position different from the fixed magnetic head; A plurality of movable magnetic heads whose positions can be controlled in the width direction of tracks on the magnetic tape, tape drive means for causing the magnetic tape to travel on the peripheral surface of the rotating cylinder at a predetermined speed, and the predetermined running speed of the magnetic tape. And a speed setting means for giving a command to the tape driving means so as to set the same first speed as during recording or an arbitrary second speed different from during recording, and the magnetic tape runs at the second speed. And a position control means for controlling the position of the movable magnetic head in the track width direction so that the movable magnetic head traces the recording track of the magnetic tape. Displacement voltage generating means for envelope-detecting a reproduction signal from the movable magnetic head and outputting a displacement voltage for position control of the movable magnetic head based on a hill-climbing control signal for controlling the detected signal to be maximum. A plurality of addition means for supplying to the position control means a sum signal of a synchronization signal for matching the inclination of the track of the movable magnetic head with the recording track on the magnetic tape, and the output from the displacement voltage generation means, The traveling speed of the magnetic tape is provided with switching means for selecting one of the reproduction signal from the fixed magnetic head and the reproduction signal from the movable magnetic head, and demodulation means for demodulating the output signal selected by the switching means. Is set to the first speed, the switching means is caused to output a reproduction signal from the fixed magnetic head, and the magnetic tape is run. When the speed is set to the second speed, when the traveling speed of the magnetic tape reaches the second speed,
The switching means is operated until a signal for activating the displacement voltage generating means and a hill climbing speed increasing signal for increasing the output of the displacement voltage generating means are output, and until the time when the movable magnetic head is on-track on the recording track. To the reproduction signal from the fixed magnetic head, and after the time when the movable magnetic head is on-track to the recording track, the output of the hill-climbing speedup signal is stopped and the reproduction signal from the movable magnetic head to the switching means. And a control means for outputting the magnetic tape image reproducing apparatus. 2. A movable magnetic head switching means for selecting reproduction signals from the plurality of movable magnetic heads on the basis of a video head switching signal, and a displacement voltage generating means for storing the head switching signal by delaying the head switching signal for a predetermined period. A delay circuit for generating a comparison timing signal, a storage means for storing the envelope detection output signal output from the envelope detection means as the timing signal, and the head stored in the storage means in synchronization with the comparison timing signal. If the envelope detection output signal of one cycle before the switching signal and the envelope detection output signal of the current cycle of the head switching signal are compared, and the envelope detection output of the current cycle is smaller than the envelope detection output signal of one cycle before. Is a comparison means for reversing the ascending / descending output, and in the opposite case holding the elevating output without inverting When the hill-climbing speed increasing signal is not output in synchronization with the video head switching signal, and if the elevation output does not reverse, the displacement voltage is increased by a predetermined value t and the elevation output reverses. In this case, the displacement voltage is reduced by a predetermined value t, and when the climbing speed increasing signal is output, the displacement voltage is larger than the predetermined value t when the elevation output is not reversed. When the ascending / descending output is reversed, the displacement voltage is decreased by the predetermined value s to output a signal for displacing the plurality of movable magnetic heads in the track width direction. The magnetic tape image reproducing apparatus according to claim 1, further comprising a driving unit.