JP2003317348A - Magnetic tape recording and reproducing method and magnetic tape recording and reproducing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic tape recording and reproducing method with which a time for fast forwarding or rewinding a tape is shortened in the case of FF or REW. <P>SOLUTION: In the magnetic tape recording and reproducing method with which a magnetic tape is fed out by driving a supply side reel motor while loading a back tension to the supply side reel motor 16 for driving a supply side reel around which the magnetic tape is wound and the magnetic tape is taken up by a take-up side reel by driving a take-up side reel motor 20 after recording or reproducing an information on the fed-out magnetic tape, when starting fast forwarding or rewinding the magnetic tape, a driving voltage of the take-up side reel motor is detected and until its value reaches a prescribed level higher than a voltage in an ordinary state during the rewinding operation or reaches a higher level, the supply side reel motor is driven to feed out the magnetic tape. After the value reaches the level, driving of the supply side reel motor is stopped to take up the magnetic tape only by the take-up side reel motor. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement of control of a reel drive system in a magnetic tape recording / reproducing apparatus such as a VTR.

[0002]

2. Description of the Related Art Currently, in a domestic VTR, a magnetic tape is pinched between a capstan and a pinch roller when the magnetic tape is traveling at a high speed (when fast-forwarding or rewinding), and the capstan motor and gear work together. There are two types: a reel that is wound up with a reel and a type that is directly wound with a reel motor installed.
There are types.

In the case of the latter type, since the feeding speed of the magnetic tape can be increased, the time required for cueing at the time of data reproduction is shortened. Unload,
It is very convenient to do this while the tape is stored in the tape cassette, because the time can be further shortened. However, in this latter case, since a reel motor is newly mounted, an increase in cost cannot be avoided. Therefore, a brushless DC motor used as a reel motor is made into a motor having high versatility as in the case of being used in other information devices, and an attempt is made to suppress the cost increase as much as possible.

Further, as in the tape running controller disclosed in Japanese Patent Application Laid-Open No. 7-262652, a predetermined back tension is applied to the supply reel motor so that the tape speed does not increase more than necessary during high speed running of the tape. In some cases, the supply side reel motor is controlled. In this case, the back tension value is detected by the tension arm.

On the other hand, in special reproduction in a magnetic tape recording / reproducing apparatus such as a VTR, there are cases where the mode change from search reproduction to normal reproduction or reproduction stop cannot be performed well.

Conventionally, in a helical scan type VTR, a video signal is recorded on a tape, and at the same time, a fixed-period control pulse synchronized with the video signal in the longitudinal direction of the tape is recorded by a fixed head.

This control pulse is, for example, VHS.
In the case of the (registered trademark) system, one cycle is a period corresponding to one frame of a video signal and also a period corresponding to one drum rotation (30 Hz). In the D-VHS (registered trademark) system, the period corresponding to one rotation of the drum is the same.

The rising edge of the control pulse is used for tape running control, and the trailing edge of the control pulse is used as the duty ratio of the recording position with respect to the rising period to change the ratio to obtain the cue information of the program. It can be used for recording.

For example, in the case of VISS (VHS index search system) and VASS (VHS address search system), a duty ratio of 60% is identified as a "0" pulse, and a duty ratio of 27.5% is identified as a "1" pulse. Record cue information and address information of programs.

When further distinguishing the wide aspect ratio of 16: 9, the duty ratios of 62.5% and 30% are "L" pulses, and the duty ratios of 57.5% and 25% are "S" pulses. Are combined for identification.

In order to determine the aspect ratio of the recorded video signal from the duty ratio of the pulse of the reproduction control signal, there is a device as disclosed in Japanese Patent Laid-Open No. 6-339102, which is the reproduction control described above. Prevents erroneous discrimination between "L" and "S" pulses of the signal,
The aspect ratio is accurately determined.

[0012]

In the magnetic tape recording / reproducing apparatus described above, the first problem is as follows.
When fast-forwarding and rewinding magnetic tape, which is high-speed running,
By reducing the load on the reel motor, for example, by reducing the winding time, a brushless DC motor that suppresses the cost increase as much as possible often has insufficient rotation torque, which is the minimum required capacity. At present, there is almost no margin when designing.

Therefore, in the acceleration state until the tape starts to run at high speed, the acceleration does not proceed as expected and it takes a considerable time to reach the constant speed state. In other words, despite the new installation of the breaker reel motor, the time saving effect could not be exhibited. Therefore,
The appearance of a magnetic tape recording / reproducing apparatus in which the acceleration is effectively advanced in the acceleration state until the tape starts to run at high speed has been awaited.

A second problem with the above-mentioned magnetic tape recording / reproducing apparatus is that the tape reaches a desired position during fast-forward or rewind search / reproduction by the user.
Even if a command such as normal reproduction or reproduction stop is issued, the tape does not stop instantaneously and often goes beyond the desired position. Then, the excessive amount increases as the track pitch of the video signal becomes narrower. As described above, when the search cannot be performed as desired, the user feels that it is not very convenient.

In recent years, the capacity of tape storage has been increasing, and the track pitch is becoming narrower. From the above, when the user fast forwards or rewinds, it is convenient if the feeding speed of the magnetic tape increases so that the time required for cueing at the time of data reproduction can be shortened. It is very convenient if the tape can quickly reach the desired position and perform normal playback or playback stop at the desired position when a command such as normal playback or playback stop is issued during return search playback. The emergence of new magnetic tape recording and reproducing devices has been awaited.

[0016]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and as a solution to the first problem, the invention according to claim 1 provides a magnetic tape 11.
The supply-side reel motor 16 for driving the supply-side reel 17 wound with is driven to drive the supply-side reel motor 16 while applying the back tension to feed out the magnetic tape 11, and onto the fed-out magnetic tape 11. In the magnetic tape recording / reproducing method of driving the winding-side reel motor 20 to wind the magnetic tape 11 by the winding-side reel 21 after recording or reproducing the information signal, the fast-forwarding or rewinding operation of the magnetic tape 11 is started. At this time, the drive voltage of the take-up reel motor 20 is detected, and the supply-side reel motor 16 is driven until the value reaches a predetermined level higher than the steady-state voltage during the take-up operation. The magnetic tape 11 is fed out, and after reaching the level, the drive of the supply-side reel motor 16 is stopped to carry out the winding operation. Only by the reel motor 20 is characterized in that to perform the winding of the magnetic tape 11.

According to the second aspect of the invention, the supply-side reel motor 16 for driving the supply-side reel 17 on which the magnetic tape 11 is wound is driven to drive the supply-side reel motor 16 while applying back tension. The magnetic tape 11
And the information signal is recorded or reproduced on the sent-out magnetic tape 11, and then the winding-side reel motor 20
The magnetic tape 1 is driven by the take-up reel 21 by driving
In the magnetic tape recording / reproducing method for winding 1, the drive voltage of the winding-side reel motor 20 for driving the winding-side reel 21 is detected during the fast-forwarding or rewinding operation of the magnetic tape 11, and the value is wound. When the voltage is lower than the steady-state voltage during the take-up operation, the magnetic tape 11 is taken up by the take-up reel 21 while applying back tension to the supply-side reel motor 16. .

In order to solve the second problem, the invention according to claim 3 winds the supply side reel 17 for sending out the magnetic tape 11, and the magnetic tape 11 sent out from the supply side reel 17. Take-up reel 21
And a recording / reproducing means 2 which is arranged between the supply side reel 17 and the winding side reel 21 and records a video signal on the magnetic tape 11, and a control signal synchronized with the video signal is generated. In a magnetic tape recording / reproducing apparatus for recording in the tape longitudinal direction at the end portion of the magnetic tape 11, a plurality of predetermined duty ratios of the pulse of the control signal are combined to obtain one or several frame periods of the video signal. A recording unit 42 that sequentially cyclically switches and records the duty ratio one by one,
43 and 44, the duty ratio of the pulse of the reproduction control signal is stored when a desired tape position is reached and a command such as normal reproduction or reproduction stop is issued during fast forward or rewind search reproduction. Storage means 48,
Counting means 4 for counting how many times the duty ratio of the pulse of the reproduction control signal circulates from the time the command is issued until the magnetic tape actually stops.
9, and rewinding means 51, 52 for rewinding the magnetic tape by the amount of the magnetic tape overshoot calculated by the storage means 48 and the counting means 49.

[0019]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. Since the embodiments described below are preferred specific examples of the present invention, various technically preferable limitations are attached, but the scope of the present invention particularly limits the present invention in the following description. Unless otherwise stated, the present invention is not limited to these modes.

A preferred embodiment of the magnetic tape recording / reproducing apparatus according to the present invention will now be described with reference to FIGS. FIG. 1 is a plan view of a tape running system of a general magnetic tape recording / reproducing apparatus, FIG. 2 is a schematic plan view showing a state in which a magnetic tape runs at high speed in FIG.
FIG. 4 is a block diagram showing a configuration example of a main part of the magnetic tape recording / reproducing apparatus according to the present embodiment, FIG. 4 is an explanatory diagram showing timing of a reel motor control signal, and FIG. 6 is an explanatory diagram showing a drive voltage of the reel motor, FIG. 6 is a block diagram showing a configuration example of another embodiment, FIG. 7 is an explanatory diagram showing a duty ratio (first example) of the control pulse, and FIG. 10 is an explanatory view showing the duty ratio of the control pulse (second example). FIG. 9 is an explanatory view showing the duty ratio of the control pulse (third example).
Is the duty ratio of the control pulse (fourth example)
11 is an explanatory diagram showing the operation of calculating the tape overshoot amount, and FIG. 12 is an explanatory diagram showing the control pulse when recording the cueing signal.

(Embodiment 1) Here, a solution to the first problem will be described with reference to FIGS. Figure 1
FIG. 6 is a plan view of a tape running system showing a parallel loading system adopted in the VHS (registered trademark) system, and is supplied (delivered) from a supply-side reel 17 connected to a supply-side reel motor 16 using a brushless DC motor. The magnetic tape 11 is wound around the rotary drum 2 through the tension pole 3, the guide pole 4, the full erase head 5, and the supply guide roller 6 by about 180 degrees, and the take-up guide roller 7, the audio / control head 8, the capstan. The winding-side reel 21 is connected to a winding-side reel motor 20 using a brushless DC motor similar to the supply-side reel motor 16 described above.

FIG. 2 is a schematic plan view showing a state in which the above-mentioned magnetic tape 11 is traveling at high speed. When the magnetic tape 11 is traveling at high speed (so-called fast forward or rewind),
Supply guide roller 6 / Take-up guide roller 7
Back to the unloading position,
Also, the magnetic tape 11 is separated from the capstan 10 and the magnetic tape 11 is stored in the tape cassette 14. In addition, 18 and 19 are guide poles, respectively.

Fast forward (FF) or rewind (REW)
At this time, the magnetic tape 11 is sent from the supply reel 17 to the take-up reel 21 at high speed via the guide poles 18 and 19. Here, a reel disk (not shown) is provided below the supply-side reel 17 and the winding-side reel 21, and the supply-side reel motor 16 and the winding-side reel motor 20 described above are attached to the reel disk. ing. In the reel motors 16 and 20, the take-up reel motor 20 rotates in a clockwise direction (forward direction), and the supply-side reel motor 16 rotates in both forward and reverse (counterclockwise) directions in some cases.

FIG. 3 is a block diagram 30 showing a structural example of the main part of the magnetic tape recording / reproducing apparatus according to this embodiment.
System control circuit 31 that constitutes this block diagram 30
Manages the feed speed and rotation direction of the reel motor control circuit 32 that controls the take-up reel motor 20 and the reel motor control circuit 33 that controls the supply reel motor 16.

The timing control circuit 34 supplies the Speed signal of the supply side reel motor 16 and F (Forward) /
R (Reverse) signal and reel motor control circuit 33
The drive voltage of the supply reel 17 is monitored and the rotation direction of the supply reel 17 is switched from the forward direction to the reverse direction or from the reverse direction to the forward direction.

FIG. 4 is a diagram showing the timing of control signals for the take-up reel motor 20 and the like. When the take-up reel motor 20 switches from the OFF state to the ON state, it starts to rotate and accelerates. Go (acceleration section shown in the figure). After that, a constant speed state is entered (constant speed section shown in the figure), and deceleration is performed before the tape stops (deceleration section shown in the figure).

Forward signal 1 of supply side reel 17
7F is when a predetermined condition is satisfied, that is, FF,
In the REW mode, the drive voltage of the take-up reel motor 20 that drives the take-up reel 21 is detected, and when the value is larger than a first predetermined value, the take-up reel motor 20 is accelerated. Because it will not move smoothly,
As shown in FIG. 4, the Forward signal 17F is switched from OFF to ON, and the supply reel motor 16
Drive voltage is applied to the reel motor 16 on the supply side.
Rotates in the direction of supplying (sending out) the magnetic tape 11.

The drive current amount is the potential difference between both ends of the resistor connected in series with the winding side reel motor 20, and its voltage is A / in the system control circuit 31 from the drive IC.
Input to D port. This input value is compared with a preset a point and b point level value, which will be described later, inside the system control circuit 31. For example, the drive voltage of the take-up side reel motor 20 is a normal 3.0V, the point a level in FIG. 5 is 4.0V, and the point b level is 2.0V.
That is, the first predetermined value means the a point level and the second predetermined value.
The predetermined value of is the b point level.

The rotation of the supply-side reel motor 16 in the direction of supplying the magnetic tape 11 accelerates the acceleration of the winding-side reel motor 20, and the winding-side reel motor 20.
When the vehicle shifts to a predetermined acceleration state, the Forward
The d signal 17F switches from ON to OFF. However, when the drive voltage of the winding-side reel motor 20 is smaller than the first predetermined value, the switching from OFF to ON is not performed.

Reverse signal 1 of the supply side reel 17
7R is switched from OFF to ON at a timing before the magnetic tape 11 is stopped in the FF and REW mode states, that is, in order to prevent the reel drive motor 20 on the winding side from being given an excessive rotational driving force. A braking force is substantially applied to the take-up reel motor 20. When the reel motor 20 on the winding side is stopped, the Reverse signal 17R changes from ON to OFF.
It is configured to switch to.

When the user receives a stop command by pressing a STOP button (not shown), the timing before the stop is the time when the command reaches the system control circuit 31, and when the user runs to the end of the tape, the supply side It is the time when the winding amount of the magnetic tape 11 on the supply-side reel 17 is reduced to a predetermined amount by controlling the winding amount of the tape in the FG pulse cycle of the reel motor 16 and the winding-side reel motor 20.

FIG. 5 shows, for example, the winding side reel motor 2
It is explanatory drawing which showed the relationship of the drive voltage of 0, and the acceleration time, and a drive voltage is suddenly applied to the winding side reel motor 20 at the time of a running start of the magnetic tape 11 in FF and REW mode, and in the figure. When the level reaches point a as shown in
The torque increases. As described above, since the take-up reel motor 20 requires time until the tape is accelerated, the supply-side reel motor 16 is rotated in the magnetic tape running direction to send out the magnetic tape 11, thereby winding the tape. The side reel motor 20 is easily accelerated.

As shown in FIG. 5, the reel motor 16 on the supply side is provided.
The drive voltage of 1 decreases once with acceleration, but increases again after a while. Then, when the level reaches the point b shown in the figure, the take-up reel motor 20 is sufficiently accelerated in the tape running direction. Therefore, since it is not necessary to rotate the supply reel motor 16 in the traveling direction, the supply reel motor 16 stops feeding the magnetic tape 11 and uses a brake mechanism (not shown) provided in the supply reel motor 16. And return to the conventional tape running method.

According to the invention of the first embodiment, FF, R
In the EW mode, it takes about 5 seconds for the tape running speed to reach the top speed (constant speed state in FIG. 4) in the past, which is about 5 seconds. The winding time can be shortened.

(Embodiment 2) Next, a method for solving the second problem will be described with reference to FIGS. In this description, the configuration of FIG. 1 described above will be appropriately referred to, and the same portions will be described using the same reference numerals.

FIG. 6 is a block diagram 40 showing a structural example of another main part of the magnetic tape recording / reproducing apparatus according to the second embodiment.
Is. The system control circuit 41 constituting this block diagram 40 generates a control reference signal (30 Hz) of one frame period synchronized with the input video signal and supplies it to the duty ratio ROM table 42.

The duty ratio ROM table 42 has a predetermined number of duty ratios of the pulse of the control signal, and the duty ratio is sequentially and cyclically switched one by one every one or several frame periods of the video signal. This data is supplied to the recording control (CTL) duty ratio generating circuit 43.

The recording CTL duty ratio generating circuit 43
Based on the data sent from the duty ratio ROM table 42 described above, a rectangular wave is supplied to the recording amplifier 44 so that the duty ratio of the pulse of the control signal becomes a plurality of predetermined ratios.

The above-mentioned rectangular wave is amplified by the recording amplifier 44, and then the switch 45 connected to the terminal REC side.
It is supplied to the control head 8 through the recording medium and is recorded as a control pulse in the longitudinal direction of the edge portion of the magnetic tape 11.

Next, the point of connecting the switch 45 to the terminal PB side to reproduce the control signal will be described. The control pulse reproduced from the control head 8 is amplified by the reproduction amplifier 46 through the switch 45 connected to the terminal PB side, and then supplied to the reproduction CTL duty ratio detection circuit 47.

The reproduction CTL duty ratio detection circuit 47 is
The duty ratio of the control pulse is detected, and the detected data is supplied to the duty ratio storage circuit 48 and the cycle count circuit 49.

The duty ratio storage circuit 48 stores the duty of the pulse of the reproduction control signal at the moment when the user reaches a desired tape position during fast forward or rewind search reproduction and issues a command such as normal reproduction or reproduction stop. The ratio is stored and the data is supplied to the system control circuit 41. The timing is sent from the reproduction speed command signal 50 to the duty ratio storage circuit 48 through the system control circuit 41.

The cycle count circuit 49 described above outputs the command from the user, that is, the normal reproduction or the reproduction stop command in the fast-forward or rewind search reproduction,
Until the magnetic tape 11 is actually stopped, the duty ratio of the pulse of the reproduction control signal is counted, and the data is supplied to the system control circuit 41. The timing of starting and ending the counting is sent to the cycle counting circuit 49 through the system control circuit 41.

The capstan servo circuit 51, in addition to rotating the capstan motor 52 by a conventional method, is calculated by the above-mentioned two circuits, that is, the duty ratio storage circuit 48 and the cycle count circuit 49,
For example, when the tape is overwhelmed from the predetermined position, the system control circuit 41 receives a command for rewinding the tape position by the excessive amount, and the tape position is wound by the excessive amount. It is configured to do a reversion.

Reference numeral 53 is a drum servo circuit for controlling the drum motor 54 connected to the rotary drum 2.

FIG. 7 is a diagram showing the duty ratio (first example) of the control pulse according to the second embodiment.

In FIG. 7, the control signal from frame 1 to frame 9 is the duty ratio R described above.
9 types of duty ratios preset in the OM table 42: 10%, 20%, 30%, 40%, 50%, 60
%, 70%, 80%, and 90%, which are configured to be switched up by stepping up, for example, 10% for each frame period of the video signal.

The control signal after the frame 10 is
When the nine kinds of duty ratios make one cycle, it is configured so as to be repeatedly recorded in a cyclic manner, and again, 10%, 20%, and so on, stepping up by 10% for each frame period of the video signal. ing.

Although the control signal explained here is made to step up by 10% for each frame period of the video signal by using nine kinds of duty ratios, it may be stepped down more finely. Of course, it doesn't matter if you step down more coarsely. When determining the duty ratio, it is preferable to perform it according to the reproduction search speed and other conditions.

FIG. 8 is a diagram showing the duty ratio (second example) of the control pulse according to the second embodiment.

In FIG. 8, the control signal from frame 1 to frame 9 is the duty ratio R described above.
9 kinds of duty ratios preset in the OM table 42: 90%, 80%, 70%, 60%, 50%, 40
%, 30%, 20%, and 10% are configured to be switched stepwise by, for example, 10% every one frame period of the video signal.

The control signals after the frame 10 are
When the nine kinds of duty ratios make one cycle, it is configured to be switched so as to be repeatedly recorded in a cyclic manner by 90%, 80%, and so on, for example, by stepping down by 10% for each frame period of the video signal. Has been done.

Although the control signal explained here is made to step down by 10% for each frame period of the video signal by using nine kinds of duty ratios, it may be stepped down more finely. Of course, it doesn't matter if you step down more coarsely. When determining the duty ratio, it is preferable to perform it according to the reproduction search speed and other conditions.

FIG. 9 is a diagram showing the duty ratio (third example) of the control pulse according to the second embodiment.

In FIG. 9, the control signals from frame 1 to frame 5 are the duty ratio R described above.
10%, which is one of nine kinds of duty ratios preset in the OM table 42, is continuously used during the five frame periods of the video signal.

The control signal from frame 6 to frame 10 is one of nine kinds of duty ratios preset in the duty ratio ROM table 20.
% Is used continuously during the 5 frame periods of the video signal.

The control signals after frame 11 are
The duty ratio is used in the same manner as described above, and when the nine types of duty ratios make one cycle, 10%, 20%, ...
For example, it is configured to be switched up by stepping up by 10% for each frame period.

The control signal described here is configured to step up by 10% every 5 frame periods of the video signal using 9 kinds of duty ratios, but the frame period may be set more finely than that. Of course, the frame period may be set coarser than that.
When determining the duty ratio, it is preferable to perform it according to the reproduction search speed and other conditions.

FIG. 10 is a diagram showing the duty ratio (fourth example) of the control pulse according to the second embodiment.

In FIG. 10, in the control signals from frame 1 to frame 5, 90%, which is one of nine kinds of duty ratios preset in the duty ratio ROM table 42, is 5 frames of the video signal. It is used continuously during the period.

The control signals from frame 6 to frame 10 are 80%, which is one of nine kinds of duty ratios preset in the duty ratio ROM table 42.
It is used continuously during the 5 frame periods of the video signal.

The control signals after frame 11 are
A similar duty ratio is used in the same manner as above,
When the kind of duty ratio has made one cycle, it is configured so that it is switched to be repeatedly recorded in a cyclic manner, such as 90%, 80%, ..., Every 5 frame periods of the video signal, for example, by stepping down by 10%. ing.

The control signal described here is configured so as to be stepped down by 10% every 5 frame periods of the video signal by using 9 kinds of duty ratios, but even if the frame period is set finer than that. It does not matter, and it is of course possible to set the frame period coarser than that. When determining the duty ratio, it is preferable to perform it according to the reproduction search speed and other conditions.

FIG. 11 is an explanatory view showing the operation of calculating the overshoot amount when the magnetic tape 11 has overshot from the predetermined position.

During fast forward or rewind search reproduction, at the moment when the user reaches a desired tape position and the user issues a command such as normal reproduction or reproduction stop (user command shown in the figure),
The duty ratio storage circuit 48 stores the duty ratio of the pulse of the reproduction control signal. (40% memory shown in the figure)

After the user's command is issued, the magnetic tape 11
The cycle count circuit 4 described above determines how many times the duty ratio of the pulse of the reproduction control signal circulates until the drive actually stops (the position where the tape actually stops in the figure).
Count at 9. Specifically, the cycle count is incremented by 1 when switching from 90% to 10%.
(Cycle count shown in the figure)

By the above operation, when the magnetic tape 11 goes beyond the predetermined position, the overshoot amount is calculated. Therefore, the system control circuit 41 issues a command for rewinding the tape position by the excess amount. The capstan servo circuit 51 receives and the capstan motor or the like rewinds the tape position by the amount of the overshoot.

Specifically, the system control circuit 41 manages the actual stop by the user's stop command and the motor FG from the capstan servo circuit 51, and checks the duty ratio during that period. Then, the capstan servo circuit 51 is instructed to slowly rotate the capstan motor 52 in the direction of returning by the excess amount, and is instructed to stop when the stored duty ratio, that is, 40% is reached.

In the above description, the case where the user stops the magnetic tape 11 at the desired position has been described.
Apart from that, there are cases where it is desired to automatically rewind the recorded program to the recording start position. In that case, it is convenient to use the cue signal.

FIG. 12 is a diagram showing control pulses when recording the cue signal.

In FIG. 12, when the cue signal is recorded, the duty ratio is not changed (the duty ratio is constant), and the signal is recorded at a predetermined duty ratio for a predetermined time.

The control signal from the frame 1 to the predetermined frame (only the frame 6 is shown in the figure) is 50%, which is one of nine kinds of duty ratios preset in the duty ratio ROM table 42. ,
It is used continuously.

The number of continuous frames may be, for example, 60 frames, or may be set to a smaller number of frames or a larger number of frames. When determining the number of frames, it is preferable to perform it according to the reproduction search speed and other conditions.

[0074]

As described above in detail, according to the magnetic tape recording / reproducing method of the first and second aspects, the acceleration is effectively advanced in the acceleration state until the high speed running of the magnetic tape is started. The time required for fast-forwarding or rewinding the magnetic tape can be shortened.

In particular, when the brushless DC motor having a low rotational torque that suppresses the cost increase as much as possible is used, the effect of the present invention is maximized in terms of cost.

According to the magnetic tape recording / reproducing apparatus of the third aspect, when the user reaches the desired tape position during the fast-forwarding or rewinding search / reproduction and issues a command such as normal reproduction or reproduction stop, Since it is possible to shift to the normal reproduction or the reproduction stop at the position, it is extremely convenient.

Particularly, when the capacity of the tape storage is increased and the track pitch is narrowed more and more, even if the tape position is overwhelmed by the user, the rewinding is performed promptly by the excess amount. , Don't feel uncomfortable.

[Brief description of drawings]

FIG. 1 is a plan view of a tape running system of a general magnetic tape recording / reproducing apparatus.

FIG. 2 is a schematic plan view showing a state where the tape runs at high speed in FIG.

FIG. 3 is a system circuit block diagram showing a configuration example of a main part of the magnetic tape recording / reproducing apparatus according to the present embodiment.

FIG. 4 is an explanatory diagram showing timing of control signals for the reel motor.

FIG. 5 is an explanatory view showing a drive voltage of the supply-side reel motor.

FIG. 6 is a system circuit block diagram showing a configuration example of another embodiment.

FIG. 7 is a control pulse duty ratio (first
It is an explanatory view showing an example).

FIG. 8 is a control pulse duty ratio (second
It is an explanatory view showing an example).

FIG. 9 is a control pulse duty ratio (third embodiment)
It is an explanatory view showing an example).

FIG. 10 is an explanatory diagram showing a duty ratio of a control pulse (fourth example).

FIG. 11 is an explanatory view showing the operation of calculating the tape overshoot amount.

FIG. 12 is an explanatory diagram showing a control pulse when recording a cue signal.

[Explanation of symbols]

1 chassis 2 rotating drums 3 tension pole 4 guide pole 5 full erase head 6 Supply guide rollers 7 Take-up guide rollers 8 audio / control heads 9 pinch rollers 10 capstans 11 magnetic tape 12 Take-up reel disc 13 Supply reel disc 14 cassettes 15 loading motor 16 Supply side reel motor 17 Supply side reel 17F Supply side reel Forward signal 17R Supply side reel Reverse signal 18 guide pole 19 Guide pole 20 Reel side reel motor 21 winding reel 30 System circuit block diagram 31 System control circuit 32 First Reel Motor Control Circuit 33 Second reel motor control circuit 34 Timing control circuit 40 system circuit block diagram 41 System control circuit 42 Duty ratio ROM table 43 Recording CTL Duty Ratio Generation Circuit 44 recording amplifier 45 switch 46 playback amplifier 47 Reproduction CTL duty ratio generation circuit 48 duty ratio memory circuit 49 cycle counting circuit 50 Playback speed command signal 51 Capstan servo circuit 52 capstan motor 53 drum servo circuit 54 drum motor

Claims (3)

[Claims] 1. A supply-side reel motor that drives a supply-side reel around which a magnetic tape is wound, drives the supply-side reel motor while applying back tension, and sends out the magnetic tape, and the sent-out magnetic tape. In the magnetic tape recording / reproducing method of winding the magnetic tape by the winding reel by driving the winding reel motor after recording or reproducing the information signal thereon, at the start of the fast-forwarding or rewinding operation of the magnetic tape, The drive voltage of the take-up reel motor is detected, and the supply-side reel motor is driven until the value reaches a predetermined level or higher higher than the steady-state voltage during the take-up operation. After feeding out and after reaching the level, the drive of the supply side reel motor is stopped, and the magnetic field is controlled by only the winding side reel motor. A magnetic tape recording / reproducing method characterized by winding a magnetic tape. 2. A supply reel motor for driving a supply reel on which a magnetic tape is wound is driven to drive the supply reel motor while applying back tension, and the magnetic tape is fed out, and the magnetic tape fed out. A magnetic tape recording / reproducing method of driving a winding-side reel motor to wind the magnetic tape by a winding-side reel after recording or reproducing an information signal on the magnetic tape, during the fast-forwarding or rewinding operation of the magnetic tape, The drive voltage of the take-up reel motor that drives the take-up reel is detected, and if the value is lower than the steady-state voltage during the take-up operation, back tension is applied to the supply-side reel motor. Meanwhile, the magnetic tape recording / reproducing method characterized in that the magnetic tape is wound by the winding reel. 3. A supply-side reel for sending out a magnetic tape, a winding-up reel for winding up the magnetic tape sent out from the supply-side reel, and a supply-side reel arranged between the supply-side reel and the winding-side reel. A magnetic tape recording / reproducing apparatus having a recording / reproducing means for recording a video signal on the magnetic tape, wherein a control signal synchronized with the video signal is recorded in a tape longitudinal direction at an end of the magnetic tape. A recording unit is provided which has a plurality of predetermined duty ratios of the pulse of the control signal, and sequentially and cyclically switches and records one duty ratio for each one or several frame periods of the video signal. During fast forward or rewind search playback, when the desired tape position is reached and a command for normal playback or playback stop is issued, Storage means for storing the duty ratio of the pulse of the raw control signal, and counting how many times the duty ratio of the pulse of the reproduction control signal circulates from the time the command is issued until the magnetic tape stops. A magnetic tape recording / reproducing apparatus comprising: a counting unit for controlling the magnetic tape and a rewinding unit for rewinding the magnetic tape by an amount of the overshooting amount of the magnetic tape calculated by the storage unit and the counting unit.