JPH06215449A - Tape driving controller - Google Patents

Abstract

PURPOSE:To control a tape tension so as to converge to a target value in a shor time by preventing vibration at the start-up time of tape running. CONSTITUTION:At the time when the tape running is started, the driving predictive value for getting the stable tape tension on the tape winding diameter at this time point is obtained in a discriminating part 64 for tape winding diameter, and the predictive value is set to an initialization part 66. Then, the driving of a reel motor 42 is performed based on this predictive value during the time is counted by a timer 66A. After the time when the tape running is started, the predictive value of an offset integration and the predictive value of a filter variable for getting the stable tape tension on the tape winding diameter are obtained in the discriminating part 64 of tape winding diameter. These predictive values are set to an offset integrating part 58 and a phase compensating filter 60 respectively, then a servo error control based on the output of a photo- inerrupter 38 is started.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a tape drive control device for adjusting tape tension in a tape drive device such as an audio tape recorder, a video tape recorder or a magnetic tape device.

[0002]

2. Description of the Related Art In a tape drive device, for example, a VTR or DAT of a helical scan system, servo control of tape tension is performed by a control device as shown in FIG. In the figure, the tape 10 is a supply reel 1.
2 and a take-up reel (not shown), and the guide 14, the tension arm post 16, the loading post 18, the head drum 20, the loading post 22, and the pinch are provided in the passage. Laura 2
4, the capstan 26 is provided in order.

The tension arm post 16 includes the arm 3
No. 0 is rotatably attached to one end, and the other end of the arm 30 is rotatably attached to the swing shaft 32 serving as a fulcrum. By the action of the arm 30 and the swing shaft 32, the tension arm post 16 can swing in the directions of arrows F1 and F2 in the figure. A torsion spring 34 is provided between the arm 30 and the swing shaft 32.
Is provided, and the arm 30 is biased in the direction of arrow F2. Therefore, if the amount of tape 10 delivered from the supply-side reel 12 is increased, the tape 10 is loosened and the tension arm post 16 moves in the direction of arrow F2. Conversely, if the amount of delivery is decreased, the tape 10 is tensioned. The tension arm post 16 moves in the direction of arrow F1.

Next, the light shield plate 3 is provided at an appropriate position on the arm 30.
6 is extended, and a photo interrupter 38 is provided around the light shielding plate 36. The photo interrupter 38 has a structure in which a light emitting diode LD and an NPN type photo transistor PT are arranged to face each other with a light shielding plate 36 in between, and a variable resistance VR for adjustment is connected to the photo transistor PT. . As a result, the position state of the light shielding plate 36 corresponding to the degree of tape tension is taken out as an electric signal. FIG. 12 shows an example thereof.

The output side of the photo interrupter 38, that is, the collector side of the phototransistor PT is connected to the inverting input side of an operational amplifier (hereinafter referred to as "OP amplifier") A via a resistor R. The OP amplifier A is for performing gain setting and phase compensation, its non-inverting input side is grounded, and its output side is connected to the inverting input side via a capacitor C. The output side of the OP amplifier A is connected to the motor drive circuit 40,
The output side of the motor drive circuit 40 is connected to the reel motor 42. The reel motor 42 drives the supply-side reel 12 to rotate.
A tape tension feedback control system is constructed as a whole.

Next, the operation of the prior art as described above will be described. The tension arm post 16 moves in the direction of arrow F1 or F2 in accordance with the tension of the tape 10. Then, the light shielding plate 36 of the arm 30 also moves, and the output voltage of the photo interrupter 38 changes according to the graph shown in FIG. This voltage fluctuation is fed back to the reel motor 42 via the OP amplifier A and the motor drive circuit 40 to control the rotation of the reel motor. As a result, the tape feed amount from the reel 12 is increased or decreased. By repeating such an operation, the light shielding plate 36 is moved to the target position (corresponding to a desired tape tension), that is, the photo interrupter 38.
The servo control is carried out so that the output of the above becomes the target control voltage.

[0007]

In the conventional tape tension servo system as described above, it is generally difficult to broaden the frequency characteristic due to the resonance of the mechanical system such as the arm 30. This is a cause of deterioration of responsiveness. For this reason, since the servo error is not immediately output at the time of starting the tape running, the reel motor 42 is not driven, and the tension arm post 16 is hit hard by the sudden increase in the tension of the tape 10 which has started running. There is. Then, the tension arm post 16 moves in the direction of arrow F1, but the arm 30 is biased in the direction of arrow F2 by the action of the torsion spring 34, so that the tension arm post 16 repeats vibration outside the linear region of the servo. Will be seen.

Even if such a vibration is once settled and enters the linear region, it takes time until it converges to the target control value because the response is poor as described above. Since a good tape tension value cannot be obtained until the convergence, for example, the contact between the recording / reproducing magnetic head and the tape 10 becomes unstable, and the signal recording / reproducing operation is disturbed. FIG. 13 shows an example of changes in tape tension over time. As shown in the figure, a large vibration occurs immediately after the tape starts to run, and then the tension converges to the target value.

Next, there is also a conventional technique in which the back torque for running the tape is controlled to be substantially constant. In this case, the back torque generated by the reel motor 42 needs to be varied within a range in which the drive voltage of the reel motor 42 and the output torque have good linearity. However, in practice, due to various factors, it is often inevitable to drive the motor even near the lower limit of the range with good linearity. Therefore, in the case where a disturbance occurs at such an operating point, in order to suppress the disturbance, an area with poor linearity or the reel motor 42 is used.
May enter the area where is stopped.

For example, when the motor drive circuit 40 is constructed by using a transistor and the control voltage is applied to the base, the control voltage is a predetermined value (for example,
When the voltage becomes 0.7 V or less, the transistor does not operate, the supply of the drive current to the reel motor 42 is stopped, and the reel motor 42 is stopped. Then, the back torque of the supply-side reel 12 required to obtain the target tape tension becomes small, the torque control linearity of the reel motor 42 deteriorates, the servo becomes unstable, and the reel motor 42 repeatedly stops / starts. The tape tension fluctuates due to the ON / OFF state.

Further, when the winding speed of the tape 10 is reduced under a constant back torque condition, if the moment of inertia on the supply side is larger than the moment of inertia on the winding side or the drive system,
The deceleration on the supply side does not catch up with the deceleration on the winding side.
Loosening or slack occurs, and winding unevenness or tape damage occurs. In addition, the touch between the head (not shown) and the tape 10 is deteriorated, and the recorded contents of the tape 10 cannot be read well, and the speed signal or the like is not output. For this reason, there is a disadvantage that the tape speed cannot be searched.

The present invention focuses on these points,
The first purpose is to perform servo control of the tape tension, which can converge to a target value in a short time to obtain a good tape tension and can perform recording / reproduction of signals without any trouble. The second purpose is to prevent slack of the tape during deceleration. The third object is to stably and satisfactorily control the tape tension constant.

[0013]

In order to achieve the above object, the first invention is to drive the tape reel based on the state of the tape tension detected by the tension detecting means to servo the tape tension to a target value. In the tape drive control device to control, at the start of tape running,
Prediction value setting means for determining the tape winding diameter of the tape reel and obtaining a drive prediction value of the tape reel in which stable tape tension is predicted to be obtained with this winding diameter, and based on the prediction value set by this Reel drive means for starting driving the tape reel.

According to a second aspect of the present invention, the tape reel is driven based on the servo error obtained by using the offset integrating means and the phase compensation filter means from the state of the tape tension detected by the tension detecting means. In a tape drive control device that servo-controls the tension to a target value, the tape winding diameter of the tape reel is determined, and an offset integration predicted value and a filter variable predicted value are predicted that a stable tape tension is obtained with this winding diameter. And a predictive value setting means for setting the offset integrating means and the phase compensation filter means, and a reel drive means for driving the tape reel based on the servo error signal obtained with the predictive value set by the offset value setting means as a reference. It is characterized by having.

A third invention has two reels, and the first invention
In a reel drive control device that controls the back torque on the first reel side when winding the tape from the reel to the second reel, the back torque is controlled to increase when the tape is decelerated during running. A back torque increase control means is provided.

A fourth aspect of the present invention is a tape drive control device for performing back torque control of a tape reel based on the state of the tape tension detected by the tension detecting means to servo-control the tape tension to a target value.
A lower limit limiter means for limiting the control amount of the servo control is provided so that the back torque of the tape reel becomes a predetermined lower limit value or more.

[0017]

According to the first aspect of the present invention, when the tape is started to travel, a drive prediction value for obtaining a stable tape tension at the tape winding diameter at that time is obtained, and the reel motor is driven based on this prediction value. Done. According to the second invention, the offset integrated predicted value and the filter variable predicted value for obtaining the stable tape tension at the tape winding diameter are obtained. Then, these predicted values are set in the offset integrating means and the phase compensation filter, and the servo control is activated. According to the main aspect of the present invention, the tape drive according to the first invention is performed at the start of tape running, and the tape drive according to the second invention is performed after the drive is started.

According to the third invention, the back torque on the tape supply side is increased when the tape running is decelerated. Therefore, the loosening and slack of the tape due to deceleration is prevented. According to the fourth aspect, since the back torque is controlled to be equal to or higher than the predetermined lower limit value, the linearity of the tape tension constant control is favorably maintained, and stable driving is performed.

[0019]

Embodiments of the tape drive control device according to the present invention will now be described in detail with reference to the accompanying drawings. The same reference numerals are used for the same components as those of the above-described conventional technique or components corresponding to the conventional technique.

<First Embodiment> First, a first embodiment of the present invention will be described with reference to FIGS. Figure 1
Shows the configuration of this embodiment. As shown in the figure, in the present embodiment, a portion which is conventionally composed of an OP amplifier A is digitally processed by using a microcomputer, and a servo is realized by software. The function block shown in the figure is included in software in the microcomputer 50, and the output side of the photo interrupter 38 described above is connected to the A / D conversion unit 52. The output side of the A / D conversion section 52 is connected to the servo error generation section 54, and the output side of the servo error generation section 54 is connected to the addition section 56 and the offset integration section 58, respectively. The output side of the offset integration section 58 is also connected to the addition section 56.

The output side of the adder 56 is the phase compensation filter 6
0, and the output side of the phase compensation filter 60 is connected to a PWM (pulse width modulation) processing unit 62.
Further, the microcomputer 50 includes a tape winding diameter discriminating section 64 and an initial setting section 66, respectively, and an output side of the tape winding diameter discriminating section 64 is an offset integration section 58, a phase compensation filter 60, and an initial setting section 66. Respectively connected to. The output side of the initial setting unit 66 is connected to the PWM processing unit 62. The output side of the PWM processing unit 62 is the output side of the microcomputer 50 and is connected to the motor drive circuit 40 via the PWM carrier removal filter 70.

Of the above units, the A / D conversion unit 52 is
This is for converting the output signal of the photo interrupter 30 into a digital signal and loading it into the microcomputer 50. The servo error generator 54 is for comparing the input data with the target value to generate a servo error. The offset accumulating unit 58 is for accumulating the upper bits of the servo error as an offset.

Next, the phase compensation filter 60 is composed of, for example, a first-order IIR (recursive) digital filter as shown in FIG. The basic operation will be described. When the integrated servo error _Xn is input, Un _-1 is multiplied by "B" by the multiplication element 36B, and added by the addition element 60C with the integrated servo error _Xn. get _n On the other hand, the delayed signal U _n-1 is multiplied by "A" in the multiplication element 60D and added to U _n in the addition element 60E.

Then, the added value U _n + AU _{n-1 is} amplified by G times by the amplifying element 60F, and a phase compensation error Y _n = (U _n + AU _n-1 ) · G is obtained. Then, the variable U _{n is set} to U _n-1, and the phase compensation error value Y _n is set to P _n.
It is supplied to the WM processing unit 38. The relationship between the output of the photo interrupter 38 and the tape tension is that the output voltage also increases when the tension is increased, as shown in FIG. Therefore, since it is necessary to perform feedback control, the phase compensation error value Y _n is inverted to −Y _n and supplied to the PWM processing unit 38.

Next, the tape winding diameter discriminating section 64 has a function of discriminating the tape winding diameter of the supply reel 12. For example, the distinction between types such as DAT 60 m tape and 90 m tape can be detected from a hole formed in the tape. The amount of tape winding from the beginning (BOT) of the tape can be detected by counting with the counter 64A. The counter 64A is reset when BOT is detected, and has a function of counting the reel pulse output by a predetermined number for each rotation of the supply-side reel 12. The tape winding diameter discriminating unit 64 has a function of discriminating the tape winding diameter of the supply reel 12 from these pieces of information.

Next, the tape winding diameter discriminating section 64 is a memory 64.
Have B. The filter variable U _n-1 , the offset integrated value F _s , and the error output Y _n in the servo loop when the tape tension is completely stable change according to the tape winding diameter, as shown in FIG. Such a relationship is obtained in advance and stored in the memory 64B. In the present embodiment, as will be described later, since the filter variable U _n-1 according to the tape winding diameter is used as a reference for the tension servo, the tape winding diameter discriminating unit 64 discriminates the tape winding diameter and applies it. The data is read from the memory 64B and output to a required location. In the following description, the memory 6
The stored data of 4B is expressed as a filter variable predicted value UE _n-1 , an offset integrated predicted value FE _s , and an error predicted value YE _n .

Next, the initial setting section 66 is for outputting the stable driving condition in the tape winding diameter at the start of tape driving to the PWM processing section 62 while the timer 66A measures the time. Next, the PWM processing unit 62 is for generating and outputting a PWM servo signal based on the input phase compensation error value −Y _n , and the PWM servo signal is
Carrier removal is performed by a PWM carrier removal filter 70 including a resistor and a capacitor.

Next, the operation of this embodiment configured as described above will be described with reference to FIGS. 4 and 5 are flowcharts of the operation, and FIG. 6 shows changes in the tape tension with time.

Operation at the start of tape running The operation at the start of tape running will be described first. When the user issues a tape running operation instruction, the tape winding diameter determining unit 64 first determines the tape winding diameter at that time, and predicts the filter variable UE _n-1 corresponding to the tape winding diameter and the offset integration predicted value. FE _s , error prediction value Y
E _n is the phase compensation filter 60 from the memory 64B, the offset integration unit 58, are output to the initial setting unit 66.

Then, in the initial setting section 66, the timer 66
During the time measured by A, the error prediction value YE _n is inverted and output to the PWM processing unit 62. In the PWM processing unit 62, PW based on the input error prediction value YE _n
An M servo signal is generated and output (FIG. 4, step S1,
S2). The PWM servo signal is supplied to the motor drive circuit 40 after carrier removal is performed by the PWM carrier removal filter 70. In the motor drive circuit 40, the reel motor 42 is driven based on the input PWM servo signal.

As described above, at the start of the operation, the drive is performed with the error prediction value YE _{n for} a certain period. As shown in FIG. 3, the error prediction value YE _n is a value at which a tape tension that is a roughly target is obtained at the winding diameter,
This corresponds to the brake torque value of the supply-side reel 12 in the stable state. Since the drive is started under such conditions,
The above-described inconvenience that the tape tension of the supply-side reel motor 42 vibrates greatly due to poor response of the servo system can be effectively prevented.

Operation after start of tape running When the timer 66A finishes measuring time, the servo control based on the output of the photo interrupter 38 is started (step S3). As described above, the phase compensation filter 60 is set with the filter variable predicted value UE _n−1 selected corresponding to the tape winding diameter, and the offset integration unit 58 is selected corresponding to the tape winding diameter. The estimated offset integration value FE _s is set. Therefore, the servo control of the tape tension is activated based on these predicted values.

This servo control is performed as shown in the flowchart of FIG. First, the photo interrupter 38
The output of is converted into a digital signal by the A / D conversion unit 52, is taken into the microcomputer 50 (step S10), and is supplied to the servo error generation unit 54. The servo error generator 54 subtracts the control target data from the input data to generate a servo error (step S11). On the one hand, this servo error is output to the addition unit 56, and on the other hand, the upper bits thereof are output to the offset integration unit 58 as offset data (step S12).

The offset integration unit 58 integrates the input data and the preset integration value, that is, the offset integration predicted value FE _s to obtain the offset integration value F _s (step S13). The offset integrated value F _s is output to the adder 56. The adding unit 56 adds the input servo error value and the offset integrated value to obtain the integrated servo error Xn (step S14), and supplies the integrated servo error Xn to the phase compensation filter 60.

Next, when the integrated servo error X _n is input to the phase compensation filter 60, the variable U _{n -1} (at first, the prediction variable UE _{n -1} which has been preset) is changed to the delay element 60A ( as well as delayed by FIG see 2), on the one hand multiplies the "B" in multiplication element 60B, obtain U _n by adding the integrated servo error X _n in addition element 60C (step S1
5). On the other hand, the delayed element of U _n-1 is multiplied by "A" in the multiplication element 60D and added to U _n in the addition element 60E.

Then, the added value U _n + AU _{n-1 is} amplified by G times by the amplification element 60F to obtain the phase compensation error value Y _n = (U _n + AU _n-1 ) · G (step S
16). Then, the variable U _{n is set} to U _n-1 (step S17) and the phase compensation error value Y is sent to the PWM processing unit 38.
_n is supplied (step S18).

In the PWM processing unit 38, a PWM servo signal is generated and output based on the input error value Y _n , and this signal is supplied to the motor drive circuit 40 after carrier removal is performed by the PWM carrier removal filter 70.
In the motor drive circuit 40, the reel motor 42 is driven based on the input PWM servo signal. The above operation is repeated.

As described above, according to the present embodiment, the tape running is started based on the error prediction value YE _n when the tape tension is completely stable, and the filter in the servo loop when the tape tension is completely stable. The servo control is started with the variable predicted value UE _n-1 and the offset integrated predicted value FE _s as initial values. Therefore, vibration at the beginning of running can be prevented and the tape tension target value can be converged in a short time. Therefore, good tape tension can be obtained and signal recording / reproduction can be performed without any trouble.

FIG. 6 shows an example of changes in tape tension with time according to this embodiment. As is clear from the figure, the vibration of the tape tension at the beginning of the tape phase is well prevented, and thereafter, it converges to the target value in a short time.

<Second Embodiment> Next, a second embodiment of the present invention will be described with reference to FIGS. 7 and 8. This embodiment has the configuration shown in FIG. 7, and the motor drive circuit 40 of the reel motor 42 that drives the supply-side reel 12
Are connected to the microcomputer 80. The motor drive circuit 86 of the reel motor 84 that drives the take-up reel 82 is also connected to the microcomputer 80.

The microcomputer 80 is for controlling the operation of the reel motors 42, 84 and the drive motor (not shown) for the capstan 26 (see FIG. 11). In particular, the back torque increase control unit 80A is provided. As a result, when the running tape 10 is decelerated, control is performed to increase the back torque.

For example, when the user instructs a high speed search operation, the microcomputer 80 gives an operation instruction to the motor drive circuit 86 to rotate the reel motor 84 at a high speed. Then, the motor drive circuit 86 drives the reel motor 84 to rotate at high speed, and the tape 10 is wound from the supply reel 12 to the take-up reel 82 at high speed. For example, DA
During the high-speed search of T, the tape running is performed at a speed 300 times (2.45 m / s) that during normal playback. At this time, the reel motor 42 on the supply side is drive-controlled by the microcomputer 80 so that the back torque is 1.1 gfcm (1 gfcm = 9.8 × 10 ⁻³ N).

In this state, for example, it is assumed that the user gives an operation instruction for stopping the tape running. Then, the microcomputer 80 gives a deceleration operation instruction to the motor drive circuit 86. With this, for example, 30 in about 3 seconds
The control is performed so as to decelerate from 0 times speed to 80 times speed (0.65 m / s).

At the same time, the back torque increase control section 80A of the microcomputer 80 issues an operation instruction to increase the back torque to the motor drive circuit 40. Thereby, for example, from 1.1 gfcm to 3.3
Back torque increases up to gfcm. This is as shown by the solid line in FIG. The broken line in the figure is a conventional example. As described above, according to the present embodiment, since the back torque of the tape running increases during deceleration, uneven winding and tape damage due to slack or looseness of the tape 10 can be favorably prevented. Also, since the touch between the head (not shown) and the tape 10 is maintained well,
The recorded contents of the tape 10 can be read well.

In the above description, the reel motor 84 on the take-up side is driven to wind the tape 10 from the supply-side reel 12 directly onto the take-up reel 82, but conversely, from the take-up reel 82. Also when rewinding to the supply-side reel 12, the same effect can be obtained by increasing the back torque by the reel motor 84. Further, the same can be applied to the case where the tape running is performed by the pinch roller 24 and the capstan 26.

<Third Embodiment> Next, a third embodiment of the present invention will be described with reference to FIGS. FIG. 9 shows the configuration of the third embodiment. In the figure,
Similar to the first embodiment, the microcomputer 90 has an A / D to which the output side of the photo interrupter 38 is connected.
The converter 52, the servo error generator 54, the phase compensation filter 60, and the PWM processor 62 are included as functional blocks. Then, the phase compensation filter 60 and the PWM
A lower limit limiter 92 is connected between the processing units 62.

Next, the lower limit limiter 92 will be described. The tape winding diameter and the supply-side reel torque of the supply-side reel 12 when performing servo control with constant tape tension have a relationship as shown in FIG. 10A, for example. The relationship between the drive voltage of the reel motor 42 and the torque of the supply-side reel 12 is as shown in FIG. Normally, in order to obtain a linear relationship as shown in FIG. 9A, the microcomputer 90 controls so as to change the drive voltage within the change range shown in FIG.

If the motor is driven near the lower limit of the change range, as described above, the linearity may be poor or the motor may be stopped due to the intrusion of disturbance. Therefore, in the present embodiment, the lower limit limiter 92 limits the drive voltage so that it does not become lower than the lower limit value of the operation limit shown in FIG.

Next, the operation of the third embodiment as described above will be explained. The tension of the running tape 10 is converted into a voltage signal by the photo interrupter 38 and supplied to the A / D converter 52 of the microcomputer 90. To be done. The servo error generation unit 54 compares the tension value fetched by the A / D conversion unit 52 with a target value, generates an error signal from the difference, and inverts the polarity and outputs the error signal. This error signal is output from the phase compensation and PWM processing unit 62 by the phase compensation filter 60.
After being subjected to PWM processing by and the carrier removal by the PWM carrier removal filter 70, it is supplied to the motor drive circuit 40. In the motor drive circuit 40, drive control of the reel motor 42 is performed based on the input error signal, and thereby constant tape tension control is performed.

In this case, the drive voltage of the reel motor 40 corresponding to the error signal due to some cause is as shown in FIG.
When the value is equal to or less than the lower limit value shown in 0 (B), the lower limit limiter 92 limits the error signal. For this reason, the torque of the supply-side reel 12 is controlled well above the limit value.

<Other Embodiments> The present invention is not limited to the above embodiments, and includes, for example, the following. (1) In addition to the first embodiment, the second embodiment or the third embodiment,
Alternatively, both of them may be combined. (2) In the above embodiment, the tension control was performed on the tape supply side, but the same applies to the case where the tension control is performed on the winding side.

(3) In the above embodiment, the back torque is applied to the tape by using the reel motor, but a mechanical brake (band brake) or an electromagnetic clutch (electromagnetic brake) may be used. (4) In addition, various design changes such as the tape tension mechanism and the configuration of the photo interrupter can be made so as to achieve the same operation, and these are also included in the present invention.

[0053]

As described above, the tape drive control device according to the present invention has the following effects. (1) Since the tape running is started based on the drive prediction value that can obtain a stable tape tension in the tape winding diameter, it is possible to favorably prevent the vibration immediately after the start of the tape running. (2) Since the servo drive for tape running is started based on the offset integrated prediction value and the filter variable prediction value that can obtain a stable tape tension at the tape winding diameter, the convergence time to the tape tension control target value Can be shortened.

(3) Since the back torque is increased during deceleration of tape running, slack or looseness of the tape during deceleration can be prevented and stable running can be obtained. (4) Since the lower limit of the back torque is set in the constant tape tension control, stable tape tension servo control can be performed.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a first embodiment of a tape drive control device according to the present invention.

FIG. 2 is a circuit diagram showing a configuration example of a phase compensation filter in the embodiment.

FIG. 3 is a graph showing the relationship between the tape winding diameter and each value with which a stable tape tension can be obtained.

FIG. 4 is a flowchart showing an operation at the start of tape running of the embodiment.

FIG. 5 is a flowchart showing an operation after the tape running of the embodiment is started.

FIG. 6 is a graph showing a change over time in tape tension in the above-mentioned example.

FIG. 7 is a configuration diagram showing a second embodiment of the tape drive control device according to the present invention.

FIG. 8 is a graph showing changes in back torque in the second embodiment.

FIG. 9 is a configuration diagram showing a third embodiment of the tape drive control device according to the present invention.

FIG. 10 is a graph showing the operation of the third embodiment.

FIG. 11 is a block diagram showing an example of a conventional device.

FIG. 12 is a graph showing a relationship between a light shield plate and a photo interrupter output in the conventional example.

FIG. 13 is a graph showing changes over time in tape tension in the conventional example.

[Explanation of symbols]

10 ... Tape, 12 ... Supply side reel, 38 ... Photo interrupter (tension detecting means), 40, 86 ... Motor drive circuit, 42, 84 ... Reel motor (reel driving means), 50, 80, 90 ... Microcomputer, 5
2 ... A / D converter, 54 ... Servo error generator, 56
... addition section, 58 ... offset integration section (offset integration means), 60 ... phase compensation filter (phase compensation filter means), 62 ... PWM processing section, 64 ... tape winding diameter determination section (predicted value setting means), 64A ... counter , 64B ... Memory, 66 ... Initial setting section, 66A ... Timer, 70 ... PWM
Carrier removal filter, 80A ... Back torque increase control section (back torque increase control means), 82 ... Take-up reel, 92 ... Lower limiter (lower limiter means).

Claims (4)

[Claims] 1. A tape drive control device for driving a tape reel based on the state of the tape tension detected by a tension detecting means to servo-control the tape tension to a target value. While determining the tape winding diameter,
Prediction value setting means for obtaining a drive prediction value of the tape reel predicted to obtain stable tape tension with this winding diameter, and reel drive means for starting driving of the tape reel based on the prediction value set thereby. A tape drive control device comprising: 2. A tape reel is driven from the state of the tape tension detected by the tension detecting means based on a servo error obtained by using an offset integrating means and a phase compensation filter means, and the tape tension is set to a target value. In the tape drive control device that servo-controls, while determining the tape winding diameter in the tape reel, and obtaining the offset integrated predicted value and the filter variable predicted value that are expected to obtain stable tape tension at this winding diameter, Prediction value setting means for setting the offset integration means and phase compensation filter means, and reel drive means for driving the tape reel based on the servo error signal obtained with the prediction value set by the reference value as a reference. A tape drive controller. 3. A tape drive control device having two reels, which controls the back torque on the side of the first reel when winding the tape from the first reel to the second reel. A tape drive control device comprising a back torque increase control means for controlling the back torque to increase during deceleration. 4. A tape drive controller for controlling the tape reel back torque on the basis of the state of the tape tension detected by the tension detecting means to servo-control the tape tension to a target value. To be greater than or equal to the specified lower limit,
A tape drive control device comprising a lower limit limiter means for limiting a control amount of the servo control.