JPS6321260B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to tape speed and tape tension control schemes for magnetic tape drives, and more particularly for direct reel-to-reel tape drives without capstans.

Conventionally, in magnetic tape drive devices such as general tape recorders, the tape speed is determined by a capstan and a pinch roller that is pressed against the capstan through the tape, and the tape tension is determined by a mechanical tape tension. Detect tape tension from a pick-up, for example a tension arm,
Either controls the motor that drives the reel on the tape supply side (supply reel) or the motor that drives the reel on the tape winding side (take-up reel), or controls the amount of tape wound on the reel, such as the winding diameter. The tape tension is controlled to be constant by detecting the winding diameter and supplying torque proportional to the winding diameter or to the take-up reel drive motor.

However, a drawback of these conventional methods is that the tape tension is not sufficiently controlled during the tape transport transition period, that is, when the tape speed rises (accelerates) and falls (decelerates). In other words, if a tension arm is used, the response of the tension arm may be slow, and if the tape winding diameter detection method is used, the acceleration of the supply and take-up reels may differ when tape transport is accelerated or decelerated. As a result, the tape may become slack or abnormal tension may be applied, resulting in damage to the tape. This tendency is particularly noticeable in recent thin tapes.

Furthermore, in a reel-to-reel drive system that does not use a capstan, such as a data recorder, especially a cassette-type data recorder, there may be some margin for deviation in tape tension or speed.
Since high precision is not required, a constant voltage is supplied to the supply reel drive motor to apply tension to the tape. Even with this method, the tape tension naturally varied depending on the tape winding diameter. However, this method cannot be said to be an ideal tape running drive method;
It could not be used in video tape recorders, high-end audio tape recorders, or high-end data recorders that require a precise tape running system.

The present invention eliminates these conventional drawbacks.

First, the principle and schematic configuration of the present invention will be explained with reference to FIG. 1 and 2 are each reel,
3 is a tape, 4 is a roller rotated by the tape 3, 5 and 6 are posts for regulating the running position of the tape 3, 7 and 8 are motors that drive reel 1 and reel 2, respectively, and 9 and 10 are respectively Torque control circuit for controlling torque of motors 7 and 8, 1
1 and 12 are tape winding diameter detection circuits for detecting the tape winding diameters wound on reels 1 and 2, respectively; 13;
1 is a torque detection circuit that detects the torque generated by the reel motor 8; 14 is a tape speed control circuit that detects the tape speed by the rotation of the roller 4; and 15 is a circuit that receives signals from the respective detection circuits 11, 12, and 13. This is an arithmetic processing circuit that performs calculations.

Furthermore, J ₁ and J ₂ are the moments of inertia of the tape, reel, and motor, R ₁ and R ₂ are the tape radius (winding diameter) of reels 1 and 2, and τ ₁ and τ ₂ are the torques generated by the reel motors 7 and 8. , T ₁ and T ₂ represent the tape tension, and A represents the tape acceleration, respectively.

Torque required for each reel 1, 2 τ ₁ , τ ₂
The counterclockwise direction is positive, and τ ₁ =AJ ₁ /R ₁ −R ₁ ·T ₁ (1) τ ₂ =AJ ₂ /R ₂ +R ₂ ·T ₂ (2). In both formulas, R ₁・ T ₁ and R ₂・ T ₂ are the torques that give tensions T ₁ and T ₂ (steady torque)
, and AJ ₁ /R ₁ and AJ ₂ /R ₂ are the torques (transient torques) that give acceleration A to each reel 1 and 2.
It is. Furthermore, J ₁ and J ₂ are values uniquely determined by the tape winding diameters R ₁ and R ₂ of reels 1 and 2, and R ₁ ,
If R ₂ can be detected, it can be easily determined.
That is, J ₁ = J ₁₁ + J ₁₂ + J ₁₃ (3) J ₁₁ : Moment of inertia of the reel J ₁₂ : Moment of inertia of the motor J ₁₃ : Moment of inertia of the tape, and J ₁₁ and J ₁₂ are constant values. . However
J ₁₃ is, J ₁₃ = π・ρ・t/2・g (R ₁ ⁴ − _{R nio} ⁴ ) ………(4) g: Gravitational acceleration ρ: Tape density t: Tape width R _nio : Tape winding Since it is an inner diameter, if R ₁ can be detected, J ₁₃ and further J ₁ can be calculated. Similarly, J ₂ can be calculated using R ₂ .

On the other hand, in equations (1) and (2), the acceleration A is the same on the supply side and the take-up side, so τ ₁ = R ₂ · J ₁ / R ₁ · J ₂ (τ ₂ - T ₂ · R ₂ ) −T ₁・R ₁ ………(5
) becomes. That is, when the tape is run in the direction of the arrow v, if the motor torque τ ₂ generated by the motor 8 that drives the reel 2 is detected, then τ ₁ is determined by equation (5).
is calculated, and by controlling the torque of the motor 7 that drives the reel 1 to τ ₁ , the accelerations of both reels 1 and 2 become the same, and the tape tension can always be kept constant. That is, tape speed control circuit 1
The signal from 4 passes through the torque control circuit 10 and controls the reel motor 8, thereby controlling the tape 3 to a predetermined speed.

On the other hand, the signal from the torque control circuit 10 is supplied to the torque detection circuit 13, which detects the torque τ ₂ generated by the (take-up) reel motor 8. Furthermore, the respective tape winding diameter detection circuits 11 and 12 detect R ₁ and R ₂ . These R ₁ , R ₂ , and τ ₂ detection signals are led to the arithmetic processing circuit 15, which calculates the above-mentioned equation (5), and uses this output to generate a torque so that the reel motor 7 emits the calculated τ ₁ . The control circuit 9 is controlled.

Next, an embodiment of the apparatus of the present invention based on the above principle and schematic configuration will be described with reference to FIGS. 2 to 6. In Fig. 2, numeral 3 denotes a tape. When traveling in the forward direction (the same direction as during recording and playback, hereinafter referred to as FWD direction), the tape travels from reel 1 to a head device (not shown), and further detects the tape speed and running direction. It is wound onto the reel 2 around the roller 4 for use. Further, when the tape 3 runs in the reverse direction (the direction opposite to that during recording and reproduction, hereinafter referred to as the REV direction), it is wound onto the reel 1 from the reel 2 around the roller 4 and the head device. Also, reel motors 7 and 8 that drive the respective reels 1 and 2
The rollers 4 are provided with encoders 16, 17, and 22 on their respective rotating shafts, and photocouplers 18, 19, 20, and 21 are provided, respectively, so as to sandwich the encoders 16, 17, and 22 therebetween. The surfaces of the encoders 16, 17, and 22 are provided with shading or notches at equal intervals so that light can pass through or be blocked. Therefore, as the reels 1, 2 and rollers 4 rotate,
Each photocoupler 18, 19, 20, 21
Pulses with a frequency corresponding to the rotational speed are extracted from each.

Here, the formula for calculating the tape winding diameter will be described. The radius of the roller 4 is r, the tape winding diameter is R, the number of pulses obtained when the encoder 22 of the roller 4 makes one rotation is N, and the number of pulses obtained from the encoder 22 during one rotation of the reel is n.
Then, R=n/N×r (6) holds true. Therefore, since the values of N and r are constant values, if the value of n is counted, the tape winding diameter R is calculated by equation (6). In this embodiment, the tape winding diameter is detected based on this. That is, the pulses obtained by the encoder 16 and photocoupler 18 as the reel 1 rotates are waveform-shaped by the waveform shaping circuit 23 (FIG. 4a) and then input to the winding diameter detection circuit 11. . Further, the pulses obtained by the encoder 22 of the roller 4 and the photocoupler 20 are also input into the winding diameter detection circuit 11 after being waveform-shaped by the waveform shaping circuit 30 (FIG. 4e). This winding diameter detection circuit 11 is composed of a counting circuit 11a and a tape winding diameter calculation circuit 11b. moreover,
The counting circuit 11a is constructed as shown in FIG. That is, encoder 1 of reel 1 described above
6 and shaped by the waveform shaping circuit 23 (FIG. 4a) is passed through the frequency divider 45.
The frequency is divided by _N1 ( _N1 is the number of pulses obtained by one revolution of the encoder 16) (FIG. 4b).
Therefore, from the rising edge (falling edge) of this pulse b to the next rising edge (falling edge) indicates one revolution of the reels 1 and 2. Next, the monostable multivibrator 46 (hereinafter referred to as MM1) is triggered by the rising edge of pulse b.
The output pulse (FIG. 4c) is input to a latch circuit 49 which uses the rising edge of this signal as a strobe signal and latches the output of the counter 48. MM146 also triggers a monostable multivibrator 47 (hereinafter referred to as MM2) with the falling signal, causing MM247 to generate a pulse as shown in FIG. 4d. This MM247 output pulse d
is used to reset the counter 48. The counter 48 receives the pulses (see e in FIG. 4) obtained from the encoder 22 of the roller 4 and shaped by the waveform shaping circuit 30, counts the number of pulses, and outputs the counted pulses to the latch circuit 49. Therefore, the timing of each signal in this counting circuit 11a is as shown in FIG. 4, and if the output pulse widths of MM146 and MM247 are sufficiently shorter than the period _t1 of pulse b,
Since t ₁ t ₂ , the digital value output from the latch circuit 49 is the number n of pulses obtained from the encoder 22 of the roller 4 during approximately one revolution of the reel 1.
The tape winding diameter calculation circuit 11b obtains this digital value n and calculates the tape winding diameter R ₁ based on equation (6).
Similarly, the tape winding diameter R ₂ is calculated by the tape winding diameter detection circuit 12.

Next, the running of the tape 3 will be explained. The knob 35 is operated to run the tape 3. This knob 35 is a rotating body, and its rotation direction determines the FWD/REV direction of tape travel, and its rotation angle determines the travel speed of the tape 3. That is,
The direction of rotation of the knob 35 is detected by the FWD/REV direction command detection circuit 36, and this circuit generates a direction command signal _Sd whose level changes to "0" or "1" in accordance with the direction of rotation. On the other hand, the rotation angle of the knob 35 is detected by the detection section of the tape speed command circuit 37, and the circuit 37 outputs a DC voltage signal _Sv whose level changes in accordance with the rotation angle.

Now, when the knob 35 is operated to move the tape 3 in the FWD direction, the switch changeover circuit 38 is controlled by the direction command signal _Sd , and the first switch 2
9, second switch 39, third switch 27,
The fourth switch 25 is set as shown in FIG. Further, the output of this switch switching circuit 38 is inputted to a torque τ ₁ calculation processing circuit 15a and a torque τ ₂ calculation processing circuit 15b, which will be described later. When the direction command signal S _d is a FWD command, the switch switching circuit 38 operates the torque τ ₁ calculation processing circuit 15a and prohibits the operation of the torque τ ₂ calculation processing circuit 15b. At the same time, a DC voltage S _v corresponding to the rotation angle of the knob 35 formed by the tape speed command circuit 37 is inputted to the speed control circuit 28 as a reference voltage for controlling the speed of the tape 3 . Furthermore, speed control circuit 2
8, a roller 4 obtained from the photocoupler 20;
Frequency discrimination is performed from a pulse signal having a frequency corresponding to the rotational speed of the tape 3, that is, a frequency corresponding to the running speed of the tape 3, and a tape speed detection DC voltage Vh corresponding to the speed of the tape 3 is input. Frequency discrimination of this pulse signal is performed by a frequency discrimination circuit 33 composed of a monostable multivibrator and an integrating circuit. The speed control circuit 28 compares the detected voltage Vh with the reference voltage S _v and controls the motor drive circuit 55 so that the reel motor 8 that drives the reel 2 generates a torque that will cause the tape to reach a predetermined speed.
is controlled via the second switch 39. At this time,
As mentioned earlier, it is necessary to calculate the torque τ 1 applied to the reel 1 in order to keep the tape tensions T ₁ and T ₂ constant, so the momentary torque τ _{2 '} of the reel motor 8 is calculated as shown in FIG. It is obtained from the torque detection circuit 41 that detects the current i flowing through the reel motor 8 and the value of the current i, and τ=K _i・i (7) K _i : The torque calculation circuit 40 detects the current i flowing through the reel motor 8 based on Calculate torque. The value is input to the torque τ ₁ calculation processing circuit 15a. The torque τ ₁ arithmetic processing circuit 15a further calculates the tape winding diameter value for each reel at that time.
Setting circuit 15c for setting R ₁ , R ₂ and tape tension T ₁ and setting circuit 15 for setting tape tension T ₂
Input the values of T ₁ and T ₂ from d and calculate the moment of inertia.
The values of J ₁ and J ₂ are calculated, and the torque τ ₁ is calculated from these values based on equation (5). Here, τ ₂ in equation (5) is the value of τ ₂ ′ obtained by the torque calculation circuit 40 from current detection of the reel motor 8 as described above.

A signal S〓 ₁ outputted based on the value of τ ₁ is inputted to the torque control circuit 26 via the fourth switch 25 . Further, this torque control circuit 26 controls a motor drive circuit 56 so that the reel motor 7 generates a torque τ ₁ .

On the other hand, when running tape 3 in the REV direction,
The tape running control method is the same as that in the FWD direction, and this time, conversely, the momentary torque τ ₁ ' applied to the reel motor 7 of the reel 1 on the tape winding side is detected, and the output torque of the motor 8 is (1 ) and equation (2) for τ ₂ τ ₂ = R ₁ · J ₂ /R ₂ · J ₁ (τ ₁ + T ₁ R ₁ ) + T ₂ R ₂ ...(8) (However, τ ₁ = τ ₁ ′) so that the torque value τ ₂ is calculated based on
The reel motor 8 of the reel 2 serving as the supply reel is controlled. That is, by operating the knob 35, the switch switching circuit 38 switches each switch 25, 27,
29 and 39 (switched to the contact side opposite to that shown in Figure 2), and at the same time, the knob 3
The reference DC voltage S _v of the desired tape running speed in the REV direction is adjusted according to the rotation angle of the tape speed command circuit 3.
7 to the speed control circuit 28. In the speed control circuit 28, as in the case of the FWD direction, the DC voltage Vh corresponding to the tape speed is compared with the reference DC voltage _Sv .
A corresponding signal is output, but this output signal is then input to a motor drive circuit 56 that drives the reel motor 7, and controls the torque of the reel motor 7 so that the tape speed becomes a predetermined value. At this time, in the same manner as described for the FWD direction, the torque detection circuit 43 and torque calculation circuit 44
The momentary torque value τ ₁ ' of this reel motor 7 is determined. This value of τ ₁ ' is input to the torque τ ₂ calculation processing circuit 15b of the calculation processing circuit 15. At this time, the operation of the torque τ ₁ calculation processing circuit 15a is stopped. The torque τ ₂ calculation processing circuit 15b further calculates the tape winding diameter value for each reel at that time.
Obtain R ₁ , R ₂ and the desired tape tension values T ₁ , T ₂ , calculate the values of the moment of inertia J ₁ , J ₂ ,
Furthermore, from these values, the torque value τ ₂ that the reel motor 8 should generate is calculated based on equation (8), and the corresponding signal S 〓 ₂ is output to the torque control circuit 26 via the fourth switch 25. do. The torque control circuit 26 controls the motor drive circuit 55 so that the reel motor 8 generates torque τ ₂ .

By the way, if you want to change the running direction of the tape 3 to the REV direction while it is running, for example, in the FWD direction, turn the knob 35 in the opposite rotation direction, but at the same time as you operate this knob 35, you can immediately change the running direction of the tape. Rather than changing, the tape 3 is still running in the FWD direction during a certain period of time during the transition of tape running. However, since the first to fourth switches 25, 27, 29, and 39 are switched in accordance with the direction of rotation of the knob 35, when only the running speed of the tape 3 is detected, the actual running speed of the tape 3 cannot be detected. Since direction information cannot be obtained, the speed control circuit 28 compares the reference DC voltage S _v corresponding to the desired speed in the REV direction with the DC voltage Vh corresponding to the tape speed in the FWD direction during this transition period, and 3, and there is a possibility that tape running may malfunction (runaway) during this transition period. That is, for example, if tape 3 is
When driving in the FWD direction at speed v ₁ , turn knob 3.
When the tape 5 is reversely rotated in the REV direction to run the tape at a speed v ₂ , if v ₁ > v ₂ , the speed control circuit 28 controls the reel motor 7 to reduce the speed of the tape 3 to v ₂ . However, since this control works to reduce the torque of the reel motor 7, if the tape 3 is still running in the FWD direction, the tape speed will actually increase in the FWD direction, and the tape 3 may run out of control. become.

In this embodiment, in order to solve this problem, information indicating the relationship between the running direction of the tape 3 and the tape running direction command is provided to the speed control circuit 28.

That is, as shown in FIG. 2, a photocoupler 21 is installed in the encoder 22 of the roller 4 so that the output pulse of the photocoupler 20 has a phase difference of 90 degrees with the output pulse of the photocoupler 20, and waveform shaping is performed to shape the output of the photocoupler 21. The output of the circuit 31 and the signal from the waveform shaping circuit 30 are supplied to a D-type flip-flop circuit 32, and the signal is set to "0" or "0" depending on whether the tape 3 is running in the FWD direction or the REV direction. 1'', that is, a detection signal indicating the running direction of the tape 3, and also outputs this detection signal and the tape running direction command signal _Sd from the FWD/REV direction command detection circuit 36 to the exclusive OR circuit 34. We are trying to supply it to In this way, the exclusive OR circuit 34
A signal is extracted from ``0'' when the tape running direction commanded by the tape running direction command signal S <sub>d</sub> matches the actual running direction of the tape 3, and becomes ``1'' when they do not match. It will be done. This signal is then input to the speed control circuit 28.

Therefore, in this embodiment, for example, while the tape 3 is traveling in the FWD direction, the knob 3
When attempting to change the running direction of the tape 3 to the REV direction by operating the tape 3, the output of the exclusive OR circuit 34 becomes "1" until the actual running direction of the tape 3 becomes the REV direction. During the period when this output is “1”,
The speed control circuit 28 ensures that the actual running of the tape 3 is REV regardless of the value of the speed detection signal Vh.
The motor drive circuit 56 is controlled so as to apply torque to the reel motor 7 until the direction is reached. Then, the speed control circuit 28 detects that the tape 3 is running in the REV direction and the output of the exclusive OR circuit 34 becomes "0", and compares the speed detection signal Vh with the reference voltage S _v to determine the desired tape speed. The motor drive circuit 56 adjusts the torque of the reel motor 7 so that
control through.

Naturally, during such tape running, as mentioned above, the torque of the reel motor 8 of the reel 2 on the tape supply side at this time is calculated by the torque τ ₂ calculation processing circuit 15b. The torque is controlled by the torque control circuit 26 so that the torque value τ 2 becomes the torque value τ ₂ . Here, if the calculated torque of the supply reel is larger than the torque of the supply reel drive motor, the excess torque is subtracted from the drive torque of the take-up reel so that the tape tension is always constant. There is.

Further, when the running of the tape 3 is switched from the REV direction to the FWD direction, contrary to the above, the same control is performed. However, at this time, only the reel motors 7 and 8 controlled by the torque control circuit 26 and the speed control circuit 28 are replaced.

The reel motors 7 and 8 that have been described so far are controlled in both the rotational direction for winding up the tape 3 and the rotational direction for feeding out the tape 3. If the motor is controlled (excited) only, the value of the motor torque on the tape supply side calculated by the arithmetic processing circuit 15 based on the detection of the motor torque on the tape winding side will act in the tape feeding direction. In other words, when τ ₁ or τ ₂ calculated by equation (5) or (8) becomes a negative value, the reel motor 7 or 8 on the supply side is controlled (excited) in the direction in which the tape 3 is fed out. ), an abnormal tension is applied to the tape 3. When using such a reel motor, in this embodiment, when the tape 3 is transferred in the FWD direction, the torque τ ₁ is calculated from the calculation processing circuit 15a, and when the tape 3 is transferred in the REV direction, the torque τ ₂ is calculated. From the processing circuit 15b,
A signal S _a whose level changes in accordance with the direction in which the motor is to be controlled (excited) is outputted through each first switch 29 and inputted to the speed control circuit 28 . As a result of the calculation by the calculation processing circuit 15, the signal S _a
However, if the direction of torque to be applied to the motor on the tape 3 supply side is at a level corresponding to the direction in which the tape 3 is fed out, the speed control circuit 28 receives this signal.
In response to S _a , the torque of the reel motor on the winding side of the tape 3 is decreased, and as a result, the calculation result of the arithmetic processing circuit 15 is that the torque of the reel motor on the supply side is reduced in the tape winding direction (reel motor 7 The reel motor on the winding side of the tape 3 is controlled so that the winding side of the tape 3 is rotated clockwise in the case of the reel motor 8 and counterclockwise in the case of the reel motor 8.

In this embodiment described above, the speed control circuit 28
To detect the torque of the reel motor, which is the object of control, we used a method to obtain the value by detecting the current i flowing through the motor, as shown in Figure 5, but other methods are shown in Figures 6 and 7. The following is explained using .

The torque generated by a motor can be determined from the motor's rotational speed vs. torque characteristic by knowing the voltage applied to the motor and the rotational speed at that time. Applying this principle, the control target of the speed control circuit 28 can be determined. This is to detect the torque of the reel motor.

The torque detection circuits 43 and 41 shown in FIG.
As shown in the figure, monostable multivibrator 5
0, 50', 51, 51', clock signal generator 5
4, counter circuits 52, 52', latch circuit 53,
53', and detects the rotational speed of the reels 1 and 2. To explain its operation, the pulses (Fig. 7a) obtained from the encoders 16, 17 and shaped by the waveform shaping circuits 23, 24 as the reels 1, 2 rotate are shown in Fig. 6 (Fig. 2). Monostable multivibrator 50,5 as shown in dotted line)
0' (hereinafter referred to as MM350, MM3'50'), MM350, MM3'50' are triggered by the falling signal, and their output pulse (Fig. 7 f) strobes the rising edge of this signal. The signals are input to latch circuits 53 and 53' which latch the outputs of the counter circuits 52 and 52'. In addition, MM350 and MM3'50' trigger monostable multivibrators 51 and 51' (hereinafter referred to as MM451 and MM4'51') with their falling signals,
A pulse g as shown in FIG. 7g is generated in the MM451, 51'. The output pulses of the MM451, 51' are used for resetting the counter circuits 52, 52'. The counter circuits 52, 52' receive a constant frequency clock pulse (h in FIG. 7) from the clock signal generator 54, count the number and output it to the latch circuits 53, 53'. Therefore,
The timing diagram for the torque detection circuits 43 and 41' is as shown in FIG.
If the output pulse widths of MM3'50', MM451, and MM4'51' _are sufficiently shorter than the period _t3 of pulse a, it becomes _t3t4 in Fig. 7, so the outputs of latch circuits 53 and 53' A certain digital value n' corresponds to a certain period of the pulse a obtained from the encoders 16,17. Therefore, the encoder 16,
When the shading on the surface of No. 17 or the interval between the notches is l, K _O・n′=l/v _R ∴v _R =l/K _O・n′……(9) v _R : Reel at that moment Rotational speed (m/s) K _O : constant (S/1) for converting pulses into time From the pulse, the momentary rotational speed of reels 1 and 2 can be found based on n'. The torque calculation circuit 4 calculates this equation (9).
4 and 40 receive the value of n' from latch circuits 53 and 53', and motor drive circuits 56 and 55
Information on the voltages applied to the reel motors 7 and 8 is obtained from , and the torques τ ₁ ′ and τ ₂ ′ at that time are calculated. In addition,
In the above, the number in parentheses is for the reel motor 8.

Furthermore, when transferring the tape in the FWD direction or the REV direction, the tape speed is controlled by the tape winding side reel via the tape speed control circuit 28, but since the reel diameter on the tape winding side changes every moment. That is, since the transfer function of the motor including the reel changes, the stability of the speed control system changes depending on the reel diameter. In order to prevent this in the present invention,
A system stability improvement compensation filter (not shown) provided in the speed control circuit 28 is varied depending on the reel winding diameter to always perform stable compensation and realize an optimal speed control system. That is, the winding diameter detection circuit 1
This can be realized by applying one or twelve outputs to the speed control circuit 28, but this is not shown in FIG. 2 to simplify the explanation.

As described above, according to the present invention, the torque of the take-up reel drive motor is not determined independently (without feedback) of the torque value to be generated by the supply reel drive motor; Since the torque of the reel drive motor on the take-up side is controlled in accordance with the state of the torque to be generated by the drive motor, the torque to be generated by the reel drive motor on the supply side may be larger than the torque of the motor,
When the supply reel drive motor is excited in only one direction of rotation, and the torque that this motor should generate is controlled in the opposite direction, the take-up reel drive motor is Abnormal tension during tape transfer transients is a drawback of conventional tape winding devices using a capstan drive system, or simplified digital recorders with a capstan-less reel drive system. Alternatively, tape sagging can be prevented.

Therefore, extremely stable tape running is possible regardless of various reel sizes or tape thicknesses. Furthermore, since the capstan, which has conventionally been generally considered indispensable for tape winding systems, can be removed, the configuration can be simplified, and the cost of the device can accordingly be reduced. Therefore, the present invention can be applied to all types of tape winding devices, from high-end types to popular types.

[Brief explanation of the drawing]

Fig. 1 is a system diagram for explaining the theoretical background of the present invention, Fig. 2 is a system diagram of a tape winding device showing an embodiment of the present invention, and Fig. 3 is a system diagram of a tape winding device according to an embodiment of the present invention. System diagram, Figure 4 is its timing diagram,
5 and 6 are system diagrams of the torque detection circuit according to the present invention, and FIG. 7 is a timing diagram thereof. 1, 2... Reel, 3... Tape, 4... Roller, 7, 8... Reel motor, 11, 12... Winding diameter detection circuit, 15... Arithmetic processing circuit, 16, 1
7, 22... Encoder, 18, 19, 20, 2
1...Photocoupler, 23, 24, 30, 31...
... Waveform shaping circuit, 26 ... Torque control circuit, 28
... Speed control circuit, 33 ... Frequency discrimination circuit, 3
5...Knob, 36...FWD/REV direction command detection circuit, 37...Tape speed command circuit, 38...
Switch switching circuit, 40, 44... Torque calculation circuit, 41, 43... Torque detection circuit, 45... Frequency dividing circuit, 46, 47, 50, 51... Monostable multivibrator, 48, 52... Counter, 4
9, 53... Latch circuit, 56, 57... Motor drive circuit.

Claims (1)

[Claims] 1 first and second motors that drive the first and second reels, respectively; tape speed detection means that detects the speed of the tape transferred between the first and second reels; first and second tape winding diameter detecting means for detecting the winding diameter of each of the two reels of tape wound on the second reel, and the torque of the first motor based on the output signal of the tape speed detecting means. a first torque control means to control, and a second torque to control the torque of the second motor based on output signals of the first torque control means and the first and second tape winding diameter detection means. control means, when the second torque control signal outputted by the second torque control means is outside a predetermined range, the first torque control means controls the second torque control signal so that the second torque control signal is within a predetermined range. A tape winding device characterized in that the first torque control signal is changed as much as possible.