JPS6118905B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention forms a track which is sequentially connected on a magnetic medium by two magnetic heads, which are attached to a rotating body and whose air gaps extend in different directions, while the magnetic medium is being transported at a constant speed. A magnetic medium on which a video signal is recorded is transferred to two magnetic heads attached to a rotating body, each having a gap extending in a different direction, while the magnetic medium is being transported at a constant speed. Expansion of the video signal reproducing device adapted to obtain a constant speed transfer playback mode in which the recorded video signal is reproduced as a reproduced video signal in the constant speed transfer mode by operating the sequentially connected tracks as described above. Regarding length.

This type of video signal reproducing device reproduces the video signal by forming a track in which a magnetic medium on which the video signal is recorded is sequentially connected by two magnetic heads having mutually different air gap extension directions, which are attached to a rotating body. This is a magnetic medium on which video signals are recorded, and the video signals recorded on the magnetic medium are reproduced as reproduced video signals in a constant speed transfer reproduction mode by sequentially scanning tracks that connect the recorded video signals in sequence. Since the two magnetic heads are attached to a rotating body and have different air gaps in different directions, the magnetic medium on which the video signal is recorded can only be transferred when the magnetic medium is stopped. Even if the recorded video signal is repeatedly reproduced by scanning with two magnetic heads of the track and the reproduced video signal is obtained as a reproduced video signal in the transfer stop reproduction mode, it is not possible to obtain the reproduced video signal by scanning with one of the magnetic heads. When the reproduced video signal obtained by the other magnetic head is obtained as a substantially satisfactory reproduced video signal, the reproduced video signal obtained by the other magnetic head is obtained in a relationship that is obtained as an unsatisfactory reproduced video signal, so that the overall result is satisfactory. It is something that cannot be obtained as something.

Therefore, the present invention aims to propose a new video signal reproducing device of this kind that can obtain a satisfactory reproduced video signal in the transfer stop reproduction mode with a simple configuration. It will become clear from the detailed description of embodiments of the invention with reference to the drawings below.

FIG. 1 shows a first embodiment of the present invention, which includes a rotating magnetic head device 2 capable of recording and reproducing video signals on a magnetic tape 1 as a magnetic medium.

This rotating magnetic head device 2 has a magnetic tape 1 which is guided diagonally in an Ω shape on a guide cylinder (not shown) and transported at a constant speed, and is arranged concentrically with the guide cylinder at the position of the guide cylinder. 30c/
s, that is, one frame period of the video signal 2T _v
Approximately installed on the rotating body 3 that rotates once every time
The image is scanned by the magnetic heads 4A and 4B, which are arranged at an interval of 180 degrees, and if the video signals to be recorded are supplied to the magnetic heads 4A and 4B, the image will be recorded as shown in FIG. For each successive even numbered field, for example, a magnetic head 4A forms each successive track 5A on the magnetic tape 1, which is inclined in the longitudinal direction of the magnetic tape 1, and for each successive odd numbered field, a similar successive track 5B is formed by the magnetic head 4B. The video signals recorded on the magnetic tape 1 are reproduced by the magnetic heads 4A and 4B from the magnetic tape 1 on which the video signals are recorded. In this case, the constant transfer speed of the magnetic tape 1 is
and 4B are appropriately selected so that the track 5A formed by the magnetic head 4A and the track 5B formed by the adjacent magnetic head 4B are connected as shown in FIG. The extending directions of the gaps 6 of the magnetic heads 4A and 4B are made to be different from each other as shown in the appendix to FIG.
When viewed from the recording pattern of horizontal synchronizing pulses on B, the pattern is generally obtained with mutually different extension directions as shown at 7A and 7B.

Since such a rotary magnetic head device 2 is found in a known rotary magnetic head device in a so-called helical two-head Ω type magnetic recording/reproducing device, no further details regarding the configuration of this rotary magnetic head device 2 will be provided. The explanation will be omitted, but as described above, the present invention reproduces the recorded video signal from the magnetic tape 1 on which the video signal is recorded as a reproduced video signal in the constant speed transfer playback mode, and also reproduces the recorded video signal as a playback video signal in the transfer stop mode. Since the object is to reproduce and obtain a reproduced video signal, a detailed explanation of the system for recording the video signal on the magnetic tape 1 will be omitted. The motor is connected to a head motor 9 which is driven at 8 and rotates at a period of _30c /s or _2Tv .
The magnetic tape 1 is configured to rotate, and the magnetic tape 1 is connected to a capstan 1 which is connected to a capstan motor 10.
1 and a pinch roller 13 which pinches and rolls the magnetic tape 1 against the capstan 11 under the control of a pinch roller rolling contact/separation control mechanism 12, and is driven by a pinch roller 13 to transfer the magnetic tape 1 at a constant speed. A control magnetic head 14 is placed in contact with the side edge of the magnetic tape 1, and a control signal of 30 c/s is supplied to the magnetic head 14, which is then connected to a track 15 extending along the side edge of the magnetic tape 1. The information is recorded in such a manner as to form a magnetic field, and is reproduced by the magnetic head 14.

Also, the reproduced video signals obtained by being reproduced from the magnetic heads 4A and 4B (these are SNA and
SNB), now it is assumed that only the magnetic head 4B is scanning the magnetic tape 1 up to time _t2 , and as a result of this scanning, the first part of the video signal recorded on the magnetic tape 1 by the magnetic head 4B is Assuming that a reproduced video signal for one field can be obtained, as shown in FIG. 3A, for the reproduced video signal SNA, the time t ₂
The second field of the video signal recorded on the magnetic tape 1 from time t ₁ earlier than time t ₂ to time t 4 after time t ₄ , and from time t ₅ after time t ₄ to time t 4. The fourth field of the video signal recorded on the magnetic tape 1 up to t ₈ is obtained as a signal consisting of..., and the reproduced video signal SNB is obtained at time t ₂ as shown in Figure 3B. The first field of the video signal recorded on the magnetic tape 1 during the period from time t ₃ before time t ₄ to time t ₆ after time t ₅ The third field of the video signal recorded in 1 is obtained as a signal consisting of . Therefore, the reproduced video signal SNA
and SNB at time _t1 ~ _t2 , _t3 ~ _t4 , _t5 ~ _t6 , _t7 ~ _t8 ,...
. . . are obtained as intermittent signals having a relationship that partially overlaps with each other.

3A obtained from the magnetic heads 4A and 4B of the rotating magnetic head device 2 as described above.
and reproduced video signals SNA and SNB as shown in B.
However, when recording a video signal on the magnetic tape 1, in order to compose a series of reproduced video signals (this is referred to as SNC) similar to the video signal, an amplifier is used as necessary. The signal is supplied to the switch circuit 17 via 16A and 16B. On the other hand, in connection with the rotating shaft 5 of the rotary body 3 of the rotating magnetic head device 2, a pulse generator 1, which is known per se, is used.
9 is provided, from which a pulse train P1 having a period equal to _the field period Tv of the video signal, consisting of pulses at time points t ₁ , t ₂ , t ₅ , . . . as shown in FIG. 3C, is obtained, This is supplied to _the timing signal forming _{circuit 20} , and from this, for example _, as shown in FIG. 0” square wave R1
It is designed so that you can get The above-mentioned switch circuit 17 is controlled by the rectangular wave R1 _, and as shown in _{FIG .} the first field up to the point in time, the second field between time _t2 and _t4 of the reproduced video signal SNA, and the third field between time _t4 and _t6 of the signal SNB. A signal consisting of minutes, . . . is obtained as the reproduced video signal SNC.

Further, as mentioned above, if the video signal supplied to the magnetic heads 4A and 4B to record the video signal on the magnetic tape 1 is in the form of a modulated wave that is frequency modulated as usual, the switch Since the reproduced video signal SNC obtained from the circuit 17 is also in the form of a modulated wave, the reproduced video signal SNC in the form of a modulated wave is supplied to a demodulation system 21, which is known per se, from which it is sent to the television picture tube. A reproduced video signal SNE capable of reproducing an image in the apparatus is obtained and supplied to the picture tube device 22, so that a reproduced image of the video signal SNE can be obtained on the display surface of the picture tube device 22.

Furthermore, a reproduction control signal (this is referred to as CP1) obtained by reproduction from the magnetic head 14 is transmitted to the amplifier 3.
1 and from this 30c/ as shown in Figure 4A.
A pulse train CP2 of 30 c/s is obtained, which is supplied to a rectangular wave forming circuit 32 composed of a monostable multivibrator, from which a 30 c/s rectangular wave train R2 as shown in FIG. 4B is obtained. On the other hand, this rectangular wave train R2 is supplied to a trapezoidal wave forming circuit 33 having a charging/discharging circuit, and from this, as shown in FIG. A trapezoidal wave train R3 consisting of a trapezoidal wave that falls relatively slowly from the falling point is obtained, and this trapezoidal wave train R3 is transmitted to the sampling and hold circuit 3.
4. On the other hand, the timing signal forming circuit 20 generates a trapezoidal wave train R3 as shown in FIG. 4D based on the pulse train P1 described above.
30c/ consisting of pulses in the falling section of each trapezoidal wave of
A pulse train P2 of s is obtained as a sampling pulse, which is supplied to the sampling and holding circuit 34.
4, as shown in FIG. 4E, each trapezoidal wave of the trapezoidal wave train R3 at the time when the former pulse is obtained from the time when each pulse of the pulse train P2 is obtained until the time when the next pulse is obtained. On the other hand, this output E1 is supplied to a smoothing circuit 35, and this smoothing circuit 35 smoothes the output E1 as shown in FIG. 4F. A DC output E2 is obtained, which is supplied to the drive circuit 8 of the head motor 9 as a control signal. In this case, the rectangular wave forming circuit 3
2 is made so that the width of each rectangular wave of the rectangular wave train R2 obtained from this can be varied as shown by the arrow in FIG. The position of the downhill section is similarly varied as shown by the arrow in FIG. 4C, and based on this, the levels of the outputs E1 and E2 are varied as shown by the arrows in FIG. It is designed so that you can get it.

As described above, two tapes having different extending directions of gaps are attached to a rotating body 3 on a magnetic tape 1 that can be transferred at a constant speed.
A video signal is recorded by forming tracks 5A and 5B sequentially connected by two magnetic heads 4A and 4B, and the magnetic tape 1 on which the video signal is recorded is transported at a constant speed.
Two magnetic heads 4A and 4B, which are attached to the rotating body 3 and whose air gaps extend in different directions, scan tracks 5A and 5B that are connected in sequence to reproduce the recorded video signal and generate a reproduced video signal. An example of a video signal reproducing device which is a premise of the present invention and is designed to obtain SNC or SNE has been clarified, but when such a video signal reproducing device is used,
If the tracks 5A and 5B on the magnetic tape 1 of the magnetic heads 4A and 4B are scanned without deviation from the tracks 5A and 5B, of course, for some reason the magnetic tape 1 and the magnetic head 4A may be scanned.
The relative velocity difference between the magnetic head 4 and 4B changes, and the magnetic head 4
Even if the respective scans of the tracks 5A and 5B of A and 4B are shifted from these tracks 5A and 5B and the magnetic heads 4A and 4B respectively scan two adjacent tracks 5A and 5B, the magnetic heads 4A and 4B The reproduced video signals SNA and SNB obtained from the magnetic heads 4A and 4B, respectively, have characteristics obtained by reproducing the video signals recorded on the tracks 5A and 5B, respectively, because the extending directions of the air gaps are different from each other. It is something. However, if the respective scans of tracks 5A and 5B of magnetic heads 4A and 4B deviate relatively from those of tracks 5A and 5B, the levels of reproduced video signals SNA and SNB obtained from magnetic heads 4A and 4B, respectively, will be compared. In some cases, the levels of the reproduced video signals SNA and SNB are obtained by varying relatively small values, and therefore the reproduced video signals SNA and SNB are
SNB cannot obtain a good S/N, and based on this, the reproduced video signals SNC to SNE also have a relatively poor S/N, so the screen on the picture tube device 22 is obtained as a relatively poor image quality. It is what it is. If the rectangular wave forming circuit 32 adjusts the width of each rectangular wave of the rectangular wave train R2 obtained from this, each trapezoidal wave of the trapezoidal wave R3 obtained from the trapezoidal wave forming circuit 33 The position of the falling interval of is changed with respect to the time position at which each pulse of the sampling pulse train P2 is obtained, and the level of the output E1 obtained from the sampling hold circuit 34 and the control signal E2 obtained from the smoothing circuit 35 accordingly. For this reason, the drive circuit 8 of the head motor 9 is controlled to control the rotational speed of the head motor 9 and thus the rotational speeds of the magnetic heads 4A and 4B, thereby changing the relative speed between the magnetic tape 1 and the magnetic heads 4A and 4B. has been changed, and therefore the magnetic heads 4A and 4
Since the deviation of the respective scans of tracks 5A and 5B of B from these tracks 4A and 4B is changed, if the screen on the picture tube device 22 is obtained as a relatively poor image quality as described above, the received image will be changed. While watching the screen on the tube device 22, adjust the width of each rectangular wave of the rectangular wave train R2 obtained from the rectangular wave forming circuit 32 as described above so that the image quality is the best. For example, the screen on the picture tube device 22 can be obtained with the best image quality.

As described above, predetermined tracks 5A and 5B are formed on the magnetic tape 1 by the magnetic heads 4A and 4B attached to the rotating body 3 in a constant speed transfer state to record video signals. A magnetic head 4 attached to a rotating body 3 is moved from a magnetic tape 1 on which a signal is recorded while the magnetic tape 1 is being transferred at a constant speed.
An example of a video signal reproducing device has been clarified in which a recorded video signal is reproduced by scanning predetermined tracks 5A and 5B by A and 4B to obtain reproduced video signals SNC to SNE. Such a video signal reproducing device is called a video signal reproducing device in which the above-mentioned reproduced video signals SNC to SNE are obtained in a constant speed transport state of the magnetic tape 1, so that a constant speed transport playback mode can be obtained. The above-mentioned reproduced video signals SNC to SNE, as well as the above-mentioned reproduced video signals SNA and SNB, are referred to as reproduced video signals in constant-speed transfer reproduction mode.

However, in such a video signal reproducing device, if the pinch roller switching/separation control mechanism 12 is controlled to separate the pinch roller 13 from the capstan 11,
It is clear that the magnetic tape 1 stops being transported while being guided by the guide cylinder, but now the magnetic tape 1 is moved between three adjacent tracks, for example, one track 5A and two tracks 5B. 5A1, 5B1 and 5A2, the scanning loci of the magnetic heads 4A and 4B are indicated by the symbol 5 in FIG.
Tracks 5A1, 5B1 and 5B as indicated by AB'
The scanning trajectory 5AB' extends linearly with an inclination angle θ _S different from the inclination angle θ _N of the track 2, and the starting end of the scanning trajectory 5AB' straddles the starting ends of the tracks 5B1 and 5A1 approximately half by half. If the end is track 5
At the ends of A1 and 5B2, approximately half of each is obtained. However, in this case, the scanning locus 5AB' and the tracks 5A1, 5B1 and 5B
2 is based on the assumption that the rotating direction of the rotating body 3, and thus the scanning direction of the magnetic heads 4A and 4B as seen on the magnetic tape 1, are in accordance with the transport direction of the magnetic tape 1.

In the video reproducing apparatus described above, if the transport of the magnetic tape 1 is stopped, the relationship between the start and end ends of the scanning trajectory 5AB' of the magnetic heads 4A and 4B and the tracks 5B1, 5A1, and 5B2 changes to the relationship described above. If the magnetic heads 4A and 4B have tracks 5B1 and 5A on the magnetic tape 1 as described above,
1, and 5B2 will be scanned repeatedly. In this case, the extension direction of the horizontal synchronizing pulse train pulse pattern recorded on the tracks 5B1 and 5B2 is different from that of the track 5A1, and the gap 6 of the magnetic heads 4A and 4B is extended accordingly. Since the directions are different from each other, the magnetic head 4A is connected to the tracks 5B1,
Even if it repeatedly scans across tracks 5A1 and 5B2, the reproduced video signal (this is referred to as SSA) obtained from this magnetic head 4A is obtained by repeatedly reproducing only the video signal recorded on track 5A1. Similarly, the magnetic head 4B is connected to the track 5.
Even if the magnetic head 4B repeatedly scans across B1, 5A1 and 5B2, the reproduced video signal (this is referred to as SSB) obtained from the magnetic head 4B remains on tracks 5B1 and 5B2.
Only the video signal to be recorded on B2 is obtained by repeated reproduction, and therefore the current track 5A
If the fourth field of the video signal is recorded in 1, the reproduced video signal from the magnetic head 4A
SSA is obtained by repeatedly reproducing the fourth field of the video signal with interruptions as shown in FIG. 3F, and the reproduced video signal SSB from the magnetic head 4B is obtained as shown in FIG. As shown in G, the field consisting of the first half of the third field and the second half of the fifth field of the video signal is obtained by repeatedly reproducing the video signal with interruptions. . In this case, the reproduced video signal SSA from the magnetic head 4A fluctuates between the maximum level at the center and approximately 1/2 of the maximum level at both ends in each obtained field section. The video signal SSB from the magnetic head 4B has a level near zero or zero at the center and the above-mentioned maximum level at both ends in each field section obtained. It is obtained by taking a swing level that varies between approximately 1/2 of the level of . Therefore, in this case, the video signal SSA obtained by reproducing from the magnetic head 4A
Even if there is no problem in practice, the video signal SSB reproduced from the magnetic head 4B has a problem.

However, in such a state where the transfer of the magnetic tape 1 is stopped, the relative positional relationship between the magnetic head 4A and the magnetic tape 1 changes as indicated by the symbol 5A' in FIG. is obtained with the same relationship as the scanning trajectory 5AB',
The relative positional relationship between the magnetic head 4B and the magnetic tape 1 is such that the scanning locus of the magnetic head 4B traverses the tracks 5A1, 5B2 and 5A2 as indicated by reference numeral 5B' in FIG. If it is obtained by having a relationship in which it is connected to and extends parallel to this, and as mentioned above, the track 5A
If the fourth field of the video signal is recorded in field 1, the reproduced video signal SSA from the magnetic head 4A is obtained as described above in FIG. 3F, and the reproduced video signal SSA obtained from the magnetic head 4B is Signal SSB
However, as shown in FIG. 3G', the fifth field of the video signal is the video signal obtained from the magnetic head 4A.
It is obtained by repeatedly reproducing intermittently at the same amplitude level as SSA. In this case, the magnetic head 4
The reproduced video signals SSA and SSB obtained from A and 4B, respectively, are obtained without any practical problems. Furthermore, when such reproduced video signals SSA and SSB are supplied to the switch circuit 17, the reproduced video signal from which the fourth and fifth fields of the video signal are alternately repeated without interruption as shown in FIG. 3H is generated. (this is referred to as SSC) is obtained, and accordingly, the demodulating system 21 reproduces the image in the picture tube device 22, which alternately and repeatedly receives the fourth and fifth fields of the video signal without interruption. Therefore, a reproduced image of the reproduced video signal SSE, that is, a still image, can be obtained on the display surface of the picture tube device 22.

Therefore, in the video signal reproducing apparatus designed to obtain the above-mentioned constant-speed transfer playback mode, the transfer of the magnetic tape 1 is stopped as described above, and as shown in FIG.
If the above-described reproduced video signal SSC or the reproduced video signal SSE based on the above-mentioned reproduced video signal SSC is obtained, this video signal reproducing device can obtain the above-mentioned reproduced video signals SSC to
This can be called a video signal reproducing device which is capable of obtaining a transfer stop playback mode by obtaining the transfer stop state of the magnetic tape 1, and also obtains the above-mentioned playback video signals SSC to SSE as well as the above-mentioned playback video signals.
SSA and SSB can be referred to as playback video signals in the transport stop playback mode.

An example of the present invention is a video signal reproducing apparatus designed to obtain the above-mentioned constant speed transfer reproduction mode.
It is designed so that the above-mentioned transfer stop regeneration mode can also be obtained, and for this reason, either one or both of the magnetic heads 4A and 4B in the above-mentioned rotating magnetic head device 2, for example, when the magnetic head 4B is located on the rotating surface of the rotating body 3. This magnetic head 4B is attached to the rotating body 3 via a piezoelectric element 40B so that the magnetic head 4B can be displaced in a direction perpendicular to the magnetic head. This will become clear from the detailed description below.

First, the magnetic head 4B of the rotating magnetic head device 2 is attached to the rotating body 3 via the piezoelectric element 40B. To describe an example of the piezoelectric element 40B, as shown in FIGS. 5 and 6, two piezoelectric plates 43 and 44 each having conductive layers 41 and 42 on both sides are used as conductive layers. The outer conductive layers 41 of the plates 43 and 44 are connected to leads 45 and 46, respectively, and the inner conductive layers 42 are connected to each other to form leads 45 and 46. If voltages of opposite polarity are applied to leads 45 and 46 with respect to the voltage applied to lead 47, both plates 43 and 44 will move in the same direction according to the voltage. Therefore, if one end of the piezoelectric element 40B is fixed to the fixed part, the other end of the piezoelectric element 40B is bent from the reference position to the fixed part.
It has a configuration that allows it to be displaced in a direction perpendicular to the plate surface of No. 4.

Next, we will describe an example configuration in which the above-mentioned magnetic head 4B is attached to the above-mentioned rotating body 3 via such a piezoelectric element 40B.As shown in FIGS. 5 and 6, one end of the piezoelectric element 40B is , rotating body 3
For example, adhesive 49 is applied to the substrate 48 to be attached to the substrate 48 so that the surfaces of the plates 43 and 44 are parallel to the substrate 48.
For example, the magnetic head 4B is attached to the free end of the plate 43 of the element 40B so that the length direction of the gap (not shown) is perpendicular to the surface of the plate 43, The magnetic head 4B is attached to the substrate 48 via the piezoelectric element 40B, and the substrate 48 is arranged so that its plate surface is perpendicular to the axis of rotation of the rotating body 3 of the rotating magnetic head device 2 described above. It has a configuration in which it is mounted on a rotating body 3. In this case, from the front lower part of the substrate 48, a plate portion 50 is integrally attached with plate pieces 50a and 50b which are opposed to opposite side surfaces of the piezoelectric element, and is integrally extended forward. Damper materials 51a and 51 are provided between each of these and the piezoelectric element 40B.
b, and as described above, the free damped vibration that tends to occur when the piezoelectric element 40B is bent with its free end to be suddenly deflected with respect to the fixed part (in this case, the substrate 48) is suppressed. The damper materials 51a and 51b can be used to absorb the liquid.

The above has clarified an example configuration in which the magnetic head 4B in the rotating magnetic head device 2 is attached to the rotating body 3 via the piezoelectric element 40B. If no voltage is applied, the free end of the piezoelectric element 40B, that is, the magnetic head 4B, is at a constant position when viewed in the direction perpendicular to the rotating surface of the rotating body 3 (this position is taken as the reference position). In the constant speed transfer playback mode, the playback video signals of the magnetic heads 4A and 4B are
SNA and SNB are obtained in exactly the same manner as described above in FIGS. 3A and 3B, respectively, and in the transfer stop regeneration mode described above,
It is clear that B can draw a scanning locus 5AB' having the above-mentioned inclination angle θ _s on the magnetic tape 1. However, as mentioned above, if the voltage applied to the leads 45 and 46 of the piezoelectric element 40B is applied to the lead 47, If voltages of opposite polarity are applied as a reference, the free end of the piezoelectric element 40B, that is, the magnetic head 4B, will be connected to the rotating body 3.
deviates from the reference position in a direction perpendicular to the plane of rotation. Therefore, now the piezoelectric element 40
If DC voltages of opposite polarity are applied to the leads 45 and 46 of B, the deviation of the magnetic head 4B from the above-mentioned reference position will change in accordance with the value of the DC voltage in this case.

Next, an example embodiment of the magnetic head position displacement signal that supplies the magnetic head position displacement signal to the piezoelectric element 40B described above in the transfer stop reproduction mode described above, and an example configuration for obtaining the signal will be described below.
The magnetic head position displacement signal E3, which is a DC voltage, from the magnetic head position displacement signal source 61 is sent to the DC amplifier 6 via the transfer stop regeneration mode switch 62.
3, and from between the output lines 64 and 66 and between 65 and 66 of this DC amplifier 63, DC voltages of the same polarity and opposite polarity as shown in FIG. The magnetic head position displacement signals E4 and 4 are obtained. These signals E4 and 4 are applied between the leads 45 and 47 and between the leads 46 and 47 of the piezoelectric element 40B, respectively. It is assumed that when the signal E3 is not supplied to the amplifier 63, no voltage is obtained between the output lines 64 and 66 and between the output lines 65 and 66 of the amplifier 63.

The above is an example of the present invention. According to such a configuration, the pinch roller 13 rolls into contact with the capstan 11 via the magnetic tape 1, so that the magnetic tape 1 is transferred at a constant speed, and also in the transfer stop playback mode. The switch 62 is off, so the signal E3 from the signal source 61 is not supplied to the amplifier 63;
3, signals E4 and 4 cannot be obtained and the piezoelectric element 40
If no voltage is applied to B, the magnetic head 4
B is at the reference position with respect to the rotating surface of the rotating body 3 together with the magnetic head 4A, so the magnetic heads 4A and 4
The video signal recorded on the magnetic tape 1 at B is reproduced as a reproduced video signal as described above in FIGS. 3A and B.
Based on this, the magnetic tape 1 as shown in FIG. 3C is reproduced by the switch circuit 17.
A series of reproduced video signals SNC are obtained from the first, second, third... field of the video signal to be recorded in the video signal, and based on this, the demodulation system 21 outputs the picture tube device 22.
In this way, a reproduced video signal SNE capable of reproducing a normal image is obtained, and thus the above-mentioned constant speed transfer reproduction mode can be obtained. Furthermore, the pinch roller contact/separation control mechanism 12 is controlled to move the pinch roller 13 away from the capstan 11, so that the magnetic tape 1 is stopped being transferred, and the transfer stop reproduction mode switch 62 is on, and the pinch roller 13 is separated from the capstan 11. Then, the signal E3 from the signal source 61 is supplied to the amplifier 63. Therefore, if the signals E4 and 4 are obtained from the amplifier 63 and are applied to the piezoelectric element 40B, the piezoelectric element 40B
The tip of the magnetic head 4B, therefore, is displaced perpendicularly from the reference position with respect to the rotating surface of the rotating body 3 in accordance with the values of the signals E4 and 4. Therefore, if the values of the signals E4 and 4 are appropriately selected, If the magnetic head 4A scans the magnetic tape 1 by forming the scanning locus SA' as described above in FIG. The fifth field of the video signal is reproduced by forming a scanning trajectory 5B', and the reproduced video signal SSA obtained from the magnetic heads 4A and 4B, respectively.
and SSB are obtained as described above in FIG. Based on this, the demodulation system 21 obtains a reproduced video signal SSE that can reproduce a still image in the picture tube device 22, and thus the above-mentioned This provides a transport stop regeneration mode that allows

As described above, according to one example of the present invention, a predetermined track is formed on the magnetic tape 1 by the magnetic heads 4A and 4B attached to the rotary body 3 while the magnetic tape is being transferred at a constant speed, and a video signal is generated. Magnetic tape 1 on which the video signal is recorded
Thus, while the magnetic tape 1 is being transported at a constant speed, predetermined tracks are scanned by the magnetic heads 4A and 4B attached to the rotating body 3, and the recorded video signal is reproduced as a reproduced video in the constant speed transport mode. signal
In the constant speed transfer playback mode for playback as SNC or SNE, the magnetic tape 1 on which video signals are recorded is recorded by scanning a predetermined track by the magnetic heads 4A and 4B while the transfer is stopped. A transfer stop playback mode is obtained in which a video signal of
The magnetic head 4B is attached to the rotating body 3 via a piezoelectric element 40B so that the magnetic head 4B is displaced in a direction perpendicular to the rotating surface of the rotating body 3.
0B can be obtained without supplying any signal in the constant speed transfer playback mode, and by supplying signals for magnetic head position displacement in the transfer stop playback mode, so video signal playback is possible. This device has a great feature in that a constant speed transfer regeneration mode and a transfer stop regeneration mode can be obtained without the overall structure of the device becoming large, heavy, or expensive.

In the above description, when the magnetic tape 1 is in a stopped state, the magnetic heads 4A and 4B scan the magnetic tape 1 by drawing the same scanning trajectory having a different inclination angle from the track on which the video signal is recorded. ,
Therefore, if it is assumed that the video signal reproduced from the magnetic head 4A is actually obtained without any problem, the video signal reproduced from the magnetic head 4B is obtained as problematic. Based on this, it has been described that the magnetic head 4B is attached to the rotating body 3 via the piezoelectric element 40B to obtain a transport stop reproduction mode. If the signal is obtained with a problem in practice, the magnetic head 4A is attached to the rotating body 3 via a piezoelectric element so as to obtain a transfer stop reproduction mode without a problem in practice. It is obvious that it can also be done.

Furthermore, in the above description, when the magnetic heads 4A and 4B scan the magnetic tape 1 while the transfer of the magnetic tape 1 is stopped, the scanning trajectories are as shown in FIG. It is assumed that the scanning locus is formed as a scanning locus that extends at a different angle of inclination from the track on which the video signal is recorded, spanning approximately half at the beginning of the track on which the two video signals are recorded. As mentioned above, when the magnetic tape 1 is stopped transferring, the magnetic heads 4A and 4B
When scanning the magnetic tape 1, the scanning locus is not necessarily as just described, but is formed as a scanning locus whose starting edge exactly coincides with the starting edge of the track on which one video signal is recorded. In this case, the intermittent reproduced video signal obtained from the magnetic head 4A will swing from the maximum (or zero) level at the beginning to the zero (or maximum) level at the end in the subsequent section. Conversely, the reproduced video signal obtained by changing the width level and obtained from the magnetic head 4B changes from zero (or maximum level) at the beginning to the maximum (or zero) level at the end in the subsequent section. Since the amplitude levels are obtained by changing, for example, the scanning trajectories of the magnetic heads 4A and 4B as described above are formed by recording two adjacent video signals starting from their starting ends as described above in FIG. It may be formed as a scanning locus that spans half of the track at the starting end of the track, or it may be formed as a scanning locus that exactly coincides with the starting end of the track where one video signal is recorded. is desirable. For this purpose, the pinch roller contact/separation control mechanism 12 may be controlled by the means described in Japanese Patent Laid-Open No. 49-51810, although a detailed explanation thereof will be omitted.

Furthermore, in the above, we have described the case in which video signals are reproduced from a magnetic tape that records video signals by forming a magnetization locus oblique to the longitudinal direction, but this is not the only case. The present invention can also be applied to a device for reproducing video signals from a magnetic sheet that records video signals by sequentially repeating the formation of a magnetization locus in the longitudinal direction, and can be applied to a number of other methods without departing from the spirit of the present invention. Variations and changes may be made.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing an example of a video signal reproducing device according to the present invention, FIG. 2 is a diagram showing a track on a magnetic tape and a scanning locus of a magnetic head, and FIGS. 3 and 4 are diagrams for explaining the same. The signal waveform diagrams, FIGS. 5 and 6, used to explain the present invention are schematic plan views showing embodiments of a configuration in which a piezoelectric element and a magnetic head that can be applied to the present invention are attached via a piezoelectric element, respectively. and a side view. In the figure, 1 is a magnetic tape, 2 is a rotating magnetic head device, 3 is a rotating body, 4A and 4B are magnetic heads, 9
is the head motor, 10 is the capstan motor, 1
1 is a capstan, 12 is a pinch roller contact/separation control mechanism, 13 is a pinch roller, 16A and 1
6B is an amplifier, 17 is a switch circuit, 21 is a demodulation system, 22 is a picture tube device, 40B is a piezoelectric element, 61
Reference numeral 62 indicates a magnetic head position signal source, 62 a transfer stop mode switch, and 63 a DC amplifier.

Claims (1)

[Claims] 1. Select a constant speed transfer playback signal and a transfer stop playback signal from magnetic tracks on which video signals are sequentially recorded on a magnetic medium by two rotating magnetic heads having different magnetic gaps and arranged on the same rotating surface. In a video signal reproducing device that can be obtained generally, at least one of the two rotating magnetic heads is mounted on a rotating body via a piezoelectric element so as to be displaced in a direction perpendicular to its rotating surface, and when the magnetic head is in a stopped state. By supplying a predetermined head position displacement signal to the piezoelectric element, the positions of the two rotary heads are relatively displaced by one track, and these two rotary heads move two connected tracks on the magnetic medium. A video signal reproducing device characterized in that a transfer stop reproduction signal is obtained by scanning alternately.