JPH08293140A - Tape running speed control device - Google Patents

Abstract

PURPOSE: To attain reduction in cost and also to make possible the tape running speed control of high speed by providing a fixed head for reading a part of information signal recorded with a rotary head as a signal for tape running speed control. CONSTITUTION: On the tape driven by a motor M1, the rotary head records the recording signal of information with an azimuth on the recording track of the tape with a helical scanning system. When the recorded signal of this tape reaches a magneto resistance element MR1 (or MR2). A part of the signal is read out as a signal D1 (or D2) for speed control. The signal D1 is applied to a motor M1 via the reproducing amplifier 10, the rectifier circuit 11, the limitter 12, the frequency-voltage converter 13, the adder 14, the driving circuit 15, etc., of a control means 60 and then an optimum tape running speed control is performed. Consequently, the frequency generating signal from a reel motor is unnecessitated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape running speed control device used in, for example, a video tape recorder (VTR) or a digital audio tape recorder (DAT).

[0002]

2. Description of the Related Art FIG. 8 shows a reel servo system used in a conventional video tape recorder.
In FIG. 8, the tape T includes a supply reel (supply reel) 402 to a take-up reel (take-up reel).
It is shown that the vehicle is traveling at 403. The tape running speed when the tape speed Vt of the tape T is increased to N times is N × Vt. This tape running speed N × Vt
However, a tape traveling speed control method based on the reel servo system controls the traveling speed so that the tape T runs at a constant speed from the beginning to the end. The equations (1) to (6) shown in FIG. 9 are derived from the parameters shown in FIG. As shown in the formula (6) of FIG. 9, in the reel servo system, the supply reel 402, the take-up reel 4
03 frequency generation signal (FG signal) Ttf
g and Tsfg are detected, and reel servo is performed so that the square thereof (the left side of Expression (6) in FIG. 9) becomes a constant value.

[0003]

As described above, the motor of the supply reel 402 and the take-up reel 4 shown in FIG.
No. 03 motor generates frequency generation signals Ttfg, T
There is a problem that it is necessary to obtain sfg, and cost reduction cannot be achieved.

Therefore, the present invention has been made in order to solve the above problems, does not require the frequency generation signal of the reel motor, can reduce the cost, and can control the running speed of the tape at high speed. It is an object of the present invention to provide a tape traveling speed control device.

[0005]

According to the invention of claim 1, in the tape traveling speed control device for controlling the traveling speed of the information recording tape, the information recording tape is driven to travel. And a rotary head device having a rotary head for recording an information signal on an information recording tape, and a part of the information signal recorded by the rotary head of the rotary head device for controlling the tape running speed. Based on a fixed head for reading, a tape running system for guiding and running the information recording tape by the driving means, and a signal for controlling the tape running speed read by the fixed head, the driving means drives. This is achieved by a tape running speed control device including a control means for controlling the running speed of the information recording tape. In the invention of claim 2, preferably, the drive means for driving the information recording tape is a reel motor of the information recording tape. In the invention of claim 3, preferably, the drive means for driving the information recording tape is a capstan motor of a tape traveling system. In the invention of claim 4, preferably, the fixed head has a magnetoresistive element head. In the invention of claim 5, the fixed head is preferably arranged in the tape running system. In the invention of claim 6, preferably, the fixed head is arranged in the fixed guide of the tape running system. In the invention of claim 7, the fixed head is preferably arranged in the rotary head device. In the invention of claim 8, preferably, the fixed head comprises a plurality of magnetoresistive element heads having different azimuths.

[0006]

According to the invention of claim 1, the rotary head of the rotary head device records a signal of information on the information recording tape. The fixed head supplies a part of the information signal recorded on the rotary head of the rotary head device to the control means as a signal for controlling the tape running speed, and the control means controls the drive of the drive means to control the information recording tape. The traveling speed can be controlled. In the invention of claim 2, the drive means is a reel motor of the information recording tape, and the control means controls the traveling speed of the tape by the reel motor. According to the invention of claim 3, the drive means is a capstan motor of the tape traveling system, and the control means controls the traveling speed of the information recording tape by the capstan motor. According to the invention of claim 4, the fixed head is a magnetoresistive element head,
Magnetoresistive element heads are
Since the reproduction output is large, it is possible to reliably reproduce the tape traveling speed control signal during high-speed access even if there is a spacing (interval) between the magnetoresistive element head and the information recording tape. Further, since the magnetoresistive element head is of the magnetic flux response type and does not depend on the access speed, the reproduction output level of the signal for controlling the tape running speed is constant. According to the invention of claim 8, since the fixed head is a plurality of magnetoresistive element heads having mutually different azimuths, it is possible to simultaneously read a plurality of tape traveling speed control signals recorded on the information recording tape.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. The examples described below are
Since it is a preferred specific example of the present invention, various technically preferable limitations are attached, but the scope of the present invention is, unless otherwise stated to limit the present invention, in the following description.
It is not limited to these modes.

FIG. 1 shows a video tape recorder equipped with the tape running speed control device of the present invention. The video tape recorder is, for example, a VHS video tape recorder. In FIG. 1, the cassette shell C can be detachably arranged on the base 20. The cassette shell C includes a supply reel (supply reel) 22 and a take-up reel (take-up reel) 24. A VTR tape (hereinafter referred to as a tape) T is fed from a supply reel 22 and wound around a take-up reel 24 side via a tape running system 30 and a rotary head device 40. The supply reel 22 is driven by the motor M0, and the take-up reel is driven by the motor M1. The tape T is guided by the tape running system 30 and runs in the direction of the arrow R. The components of the tape running system 30 will be described. The impedance roller 31, the guide roller 32, and the fixed guide 33 of the tape running system 30 are arranged on the tape inflow side of the rotary head device 40. 1 to 3, the tape running speed control device includes a motor M1 as a driving unit, a rotary head device 40, and a tape running system 3.
0, and the control means 60.

On the other hand, the fixed guide 34, the guide roller 35, the impedance roller 36, and the fixed head 5
0, the pinch roller 37, the capstan 38, and the guide roller 39 are arranged on the tape outflow side of the rotary head device 40. The fixed guides 33 and 34 are attached so as to be inclined with respect to the base 20, and helically scan the tape T with respect to the rotary head device 40. These fixed guides 33 and 34 are arranged near the rotary head device 40 that is arranged at an inclination. By driving the capstan motor M2, the capstan 38 and the pinch roller 37 cause the tape T to travel in the arrow R direction by friction. In the tape running system 30,
Tape T is impedance roller 31 and guide roller 3
It is wound around the outer peripheral surface of the rotary head device 42 from the fixed guide 33 passing between the two. Then, the tape T passes through the fixed guide 34, the guide roller 35 and the impedance roller 36, passes near the fixed head 50, and is wound around the take-up reel 24 by the capstan 38 via the guide roller 39. Has become.

The rotary head device 40 shown in FIG.
1 and a fixed drum 42. The rotary drum 41 is
It has one or more magnetic heads H. The rotary drum 41 is rotated in the direction of arrow V by a motor (not shown) so that the magnetic head H records an information signal on the tape T in a recording track pattern as shown in FIG. There is. The fixed head 50 is arranged between the guide roller 35 and the capstan 38. The fixed head 50 preferably comprises two magnetoresistive element heads MR1, MR as shown in FIGS.
Have two. These magnetoresistive element heads MR1,
The MR2 is a head including azimuths MA1 and MA2 different from each other. This MR head MR
1 and MR2 are magnetoresistive hardening type thin film heads (also referred to as MR heads), the resistance of which depends on the relative angle between the direction of magnetization of the magnetoresistive element and the direction of current flowing through the magnetoresistive element. Is used. In this type of magnetoresistive element head, even if there is a spacing between the magnetoresistive element head and the tape T, if there is a change in the magnetic flux, a reproduced output of the information signal recorded on the tape T can be obtained. .

As shown in FIG. 2, the magnetoresistive element head M
R1 is a recording track TA (TA1, TA2, TA2) of a signal of information recorded by the magnetic head H of the rotary head device 40 along a broken line L1 along the tape edge TE as the tape T runs in the R direction. From ---), the signal D1 for controlling the tape running speed can be reproduced. Similarly, the magnetoresistive element head MR2 is
Along the broken line L2 along the tape edge TE, from the recording track TB (TB1, TB2, ---) of the signal of the information recorded by the magnetic head H of the rotary head device 40, the tape running speed control signal D2 is obtained. Is ready to play. Azimuth MR1 is a recording track TA
It has a sloped azimuth corresponding to (-) azimuth of. Similarly, the azimuth MA2 has a tilted azimuth corresponding to the (+) azimuth of the recording track TB.

Next, FIG. 3 shows the control means 60 of FIG. 1 in detail. The control means 60 controls the drive of the motor M1 of the take-up reel 24 based on the tape running speed control signal D1 (or D2) obtained from the magnetoresistive element MR1 or MR2 of the fixed head 50 to record information. It is a means for controlling the running speed of the tape T. The magnetoresistive element MR1 of the fixed head 50 passes through the reproduction amplifier 10, the control circuit 11 and the limiter 12,
It is connected to a frequency-voltage converter (F / V converter) 13. The adder 14 uses the frequency-voltage converter 13
And a reference voltage Vbias and a reference voltage Vref in the tape constant speed state. The adder 14 is the drive circuit 1
5 is connected to the motor M1 of the take-up reel 24.

Next, the operation of the tape traveling speed control device described above will be described. By driving the motors M1 and M2 and the capstan motor M2 of FIG. 1, the tape T is fed from the supply reel 22 to the take-up reel 24 via the tape running system 30 while maintaining an appropriate tension. In this case, in the rotary head device 40, since the rotary drum 41 is rotated by the motor (not shown),
As shown in FIG. 2, the magnetic head H employs the helical scan method, as shown in FIG.
Information recording signal TA with azimuth A or (+)
The information recording signal TB with the azimuth B is recorded. Then, the tape T passes from the rotary head device 40 through the fixed guide 34 and the guide roller 35, and then the fixed head 5
Reaches 0. As shown in FIG. 2, the fixed head 50 relatively moves as the tape T runs in the direction of arrow R. That is, the magnetoresistive element MR1 of the fixed head 50 relatively moves along the broken line L1, and the magnetoresistive element MR2.
Moves relatively along the broken line L2. Fixed head 5
0 indicates that the magnetoresistive element MR1 records the recording tracks TA (TA1, TA2, ...
The shaded portion corresponding to −) is the signal D1 for tape speed control.
Read as. Similarly, the magnetoresistive element MR2 reads the shaded portion of the recording track TB (TB1, TB2, ---) as the tape speed control signal D2. Based on the signals D1 and D2 thus read, the control means 60
1 controls the drive of the motor M1 of FIG. 1 and controls the running speed of the tape T as follows.

In FIG. 3, a tape running speed control signal D1 obtained from, for example, the magnetoresistive element MR1 of the magnetic head 50 enters the reproducing amplifier 10. Reproduction amplifier 10
4 outputs the reproduction amplifier output (A) of FIG. 4 to the rectifier circuit 11 in correspondence with the tape speed shown in FIG. 4, the speed PS1 slower than the constant speed PS, or the speed PS2 faster than the constant speed PS. . In FIG. 4, the tape speed is constant P so that the state of control of the tape running speed can be seen.
An example is shown in which a speed PS1 slower than S, a constant speed PS, a speed PS2 faster than the constant speed PS, and a constant speed PS are changed in this order. The reproducing amplifier 10 changes according to the tape speed.
The reproduction amplifier output (A) is output to the rectifier circuit 11. The output (A) of the reproduction amplifier has a quadrangle shape in which the horizontal axis of the rhombus extends or contracts depending on the tape speed.

Next, the rectifier circuit 11 outputs the rectified waveform (B) shown in FIG. This rectified waveform (B) is an envelope waveform. Next, the rectified waveform (B) from the rectifier circuit 11
Is input to the limiter 12, the limiter 12 outputs the limiter output (C) according to the threshold voltage Vth.
Is output. This limiter output (C) is a rectangular wave as shown in FIG. This limiter output (C) has a low frequency when the tape speed is slower than the constant speed PS1 and is higher when the tape speed is faster than the constant speed PS2. . The limiter output (C) is input to the frequency-voltage converter 13. The frequency-voltage converter 13 performs voltage conversion such that the output voltage becomes small when the frequency of the limiter output (C) is high, and the output voltage (D) becomes large when the frequency of the limiter output (C) is low. Convert voltage to.

Next, the output voltage (D) and the reference voltage Vbias are added to the adder 14. Then, the reference voltage Vref in the tape constant speed state is subtracted and input to the adder 14. That is, the adder 14 subtracts the reference voltage signal Vref indicating the constant speed state from the output voltage (D) and adds the reference voltage Vbias for driving the motor at the constant speed. As a result, the adder 1
Reference numeral 4 gives a control voltage (E) to the drive circuit 15, and the drive circuit 15 drives the motor M1. As shown in FIG. 4, the control voltage (E) is equal to the reference voltage Vbi in the section where the tape speed is slower than the constant speed PS1.
The voltage becomes higher than as, and the motor drive voltage increases. On the other hand, tape speed P is faster than constant speed
In the section of S2, the control voltage (E) falls below the reference voltage Vbias, and the drive voltage of the motor falls. This allows the tape to run at a constant speed.

As described above, in the embodiment shown in FIGS. 1 to 4, unlike the prior art, the servo control is performed by obtaining the frequency generation signal from the reel motor (the motor for the supply reel, the motor for the take-up reel). There is no need to do it.
Therefore, the frequency generators of both motors are unnecessary, and the cost can be reduced. Also, with the fixed head 50,
By controlling at least part of the information signals of the recording tracks TA and TB already recorded by the magnetic head H of the rotary head device 40 at the same time as the control of the tape traveling speed, the tape traveling control can be performed at high speed. It is possible. The fixed head 50 includes the magnetoresistive element heads MR1 and MR2.
By adopting, the reproduction output of the signal for controlling the tape running speed is larger than that of the conventionally used induction type head. For this reason, when the tape T is accessed at high speed by the tape running system 30, the fixed head 50 and the tape T are
Even if there is a spacing (interval) between, the reproduction output can be made large. Further, since the magnetoresistive element head is a magnetic flux response type head, the reproduction output level becomes constant without depending on the access speed, and it is suitable for tape running speed control. Thus, when controlling the tape running speed of the video tape recorder, at least a part of the signal recorded by the rotary head device is detected by using the fixed head 50, and the tape running obtained by the fixed head 50 is detected. The control means 60 can optimally control the motor based on the speed control signal.

Next, another embodiment of the present invention will be described with reference to FIG. FIG. 5 shows the rotary head device 140. The rotary head device 140 has a rotary drum 141 and a fixed drum 142. The rotary drum 141 has one or more magnetic heads H. Fixed drum 14
2 is the magnetoresistive elements MR1 and MR2 as shown in FIG.
have. Thus, the magnetoresistive element head MR
1, MR2 to the fixed drum 142 of the rotary head device 140
Unlike the embodiment shown in FIG. 1, the fixed head 50 does not need to be set by installing the fixed head 50.

Next, still another embodiment of the present invention will be described with reference to FIGS. 6 and 7. The video tape recorder of the embodiment shown in FIG. 6 has substantially the same structure as the video tape recorder of the embodiment of FIG. Therefore, in the embodiment of FIG. 6, the same components as those of the embodiment of FIG. 1 are designated by the same reference numerals and the description thereof will be omitted. In the embodiment of FIG.
Different from the above embodiment, for example, two magnetoresistive elements MR1 and MR2 are set in the fixed guide 234.
FIG. 7 shows the fixed guide 234 in an enlarged manner.
The two magnetoresistive element heads MR1 and MR2 are the tape T
It is arranged corresponding to. This fixed guide 234 is
It is arranged to be inclined with respect to the base 20. Thus, the magnetoresistive element heads MR1 and MR2 are fixed to the fixed guide 2
If it is provided in 34, the fixed head 50 of FIG. 1 can be omitted, and unlike the embodiment of FIG. 5, the normal rotary head device 40 can be used as it is.

In the above-described embodiment, it is not necessary to obtain the frequency generation signal from the reel motor (supply motor, take-up motor) and perform servo control. Since the fixed head can read the signal of information recorded by the rotary head device at the same time as the tape traveling speed control, high speed tape control can be performed. Unlike the induction type head, the magnetoresistive element head has a large reproduction output level, so that even if there is spacing between the tape and the magnetoresistive element head during high-speed access, the reproduction output for tape running speed control can be reliably performed. Is obtained. Further, since the magnetoresistive element head is of the magnetic flux response type and does not depend on the access speed, the reproduction output level is constant, which is suitable for high speed tape speed control.

The present invention is not limited to the above embodiment. For example, in the above-described embodiments, an analog or digital video tape recorder is taken as an example, but the present invention can be applied to, for example, a digital audio tape recorder, a data streamer, or the like. In the above-described embodiment, the control means 60 controls the drive of the motor of the take-up reel 24. However, the present invention is not limited to this, and may of course control the drive of the motor M2 for the capstan 38 of FIG. Absent.

[0022]

As described above, according to the present invention, the frequency generation signal of the reel motor is not required, the cost can be reduced, and the running speed of the tape can be controlled at high speed.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a video tape recorder including a tape traveling speed control device of the present invention.

FIG. 2 is a diagram showing an example in which a fixed head reads a signal recorded by a rotary head device of the video tape recorder shown in FIG.

FIG. 3 is a circuit diagram showing an example of control means in FIG.

FIG. 4 is a diagram showing waveforms of respective portions of the control means of FIG.

FIG. 5 is a perspective view showing another embodiment of the present invention.

FIG. 6 is a perspective view showing still another embodiment of the present invention.

FIG. 7 is an enlarged view showing a fixed guide of the embodiment of FIG.

FIG. 8 is a diagram showing a reel servo system of a conventional video tape recorder.

9 is a diagram showing a control formula of the reel servo system of FIG.

[Explanation of symbols]

 30 tape running system 40 rotary head device 50 fixed head 60 control means M1 motor (driving means) M2 motor (driving means) MR1, MR2 magnetoresistive element head

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tomohiro Ikegami 6-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation

Claims (8)

[Claims] 1. A tape running speed control device for controlling a running speed of an information recording tape, a driving means for driving the information recording tape to run, and recording a signal of information on the information recording tape. A rotary head device having a rotary head, a fixed head for reading a part of the information signal recorded by the rotary head of the rotary head device as a signal for controlling the tape running speed, and a drive means for guiding the information recording tape. A tape running system for running the tape, and a control means for controlling the running speed of the information recording tape by controlling the driving of the driving means based on the tape running speed control signal read by the fixed head. A tape running speed control device comprising: 2. The tape traveling speed control device according to claim 1, wherein the drive means for driving the information recording tape is a reel motor for the information recording tape. 3. The tape running speed control device according to claim 1, wherein the driving means for driving the information recording tape is a capstan motor of a tape running system. 4. The tape running speed control device according to claim 1, wherein the fixed head has a magnetoresistive element head. 5. The tape running speed control device according to claim 4, wherein the fixed head is arranged in a tape running system. 6. The tape running speed control device according to claim 4, wherein the fixed head is arranged on a fixed guide of a tape running system. 7. The tape running speed control device according to claim 4, wherein the fixed head is arranged in the rotary head device. 8. The tape running speed control device according to claim 4, wherein the fixed head comprises a plurality of magnetoresistive element heads having different azimuths.