JPH09180311A - Magnetic recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high precision tape traveling system by suppressing fluctuation of tape speed due to tension control. SOLUTION: A tension error ferr is calculated from the tension of a magnetic tap detected by a tension sensor guide 10 and a target tension by an adder 3b and a tension system gain 30b. A tension take-up reel gain Gdt is calculated from winding diameters of a supply side reel 8b and a take-up side reel 8a respectively and an increasing rate of tension generated between the supply side reel and the take-up side reel by a calculating part 2. The product of the tension error ferr and the tension take-up reel gain Gdt is calculated by a multiplier 4a. The supply side reel 8b is rotated by a supply side reel driving circuit 6b based on the tension error ferr . The take-up side reel is rotated by a tale-up side reel driving circuit 6a based on output of the multiplier 4a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing apparatus such as a VTR, and more particularly to a magnetic recording / reproducing apparatus capable of precisely controlling the tension of a magnetic tape.

[0002]

2. Description of the Related Art In a magnetic recording / reproducing apparatus such as a VTR,
In order to perform accurate and high-density recording / reproducing, the running speed of the magnetic tape must be kept substantially constant, and the tape tension at the drum entrance should be made almost constant. This also applies to so-called high-speed search, in which the tape speed and tape tension are controlled by the left and right reel motors without using the capstan to drive the tape.

In this reel-to-reel tape feeding technique, normally,
Speed control and tension control are performed. Speed control is tape speed information calculated from the rotation information of both reels,
Alternatively, it is a control for controlling the reel on the take-up side using speed information proportional to the amount of movement of the tape, which is the output of a rotation detector that rotates in contact with the tape, while tension control is information on the winding radius of the reel or This is a control for controlling the supply side reel from the tape tension information.

However, in the method of performing both the speed control and the tension control as described above, there is a so-called mutual interference in which the torque control or the speed operation by either one of the controls affects the other control.
There is a problem that speed fluctuation and tension fluctuation increase.

As a method for solving the above problems, for example, Japanese Patent Laid-Open Nos. 1-158654 and 4-790.
The method described in Japanese Patent No. 56 is known.

In the control method disclosed in Japanese Unexamined Patent Publication No. 1-158654, speed control and tension control are performed using both reel motors, and the inertia and reel winding of each reel motor are used as the control gain. The value obtained from the radius is used. According to this method, the mutual interference described above can be suppressed.

Further, in the method described in Japanese Patent Laid-Open No. 4-79056, the tension control is performed by open loop control, but in order to suppress interference with the speed control system,
The product of the control voltage (speed control voltage) to the winding-side reel motor and a value proportional to the linear acceleration ratio of each reel is applied to the supply-side reel together with the tension control voltage obtained from the reel winding radius. According to this method, it is possible to suppress interference with the speed control system and improve control performance.

[0008]

However, the magnetic recording / reproducing apparatus which controls the running of the tape by the above-mentioned control method has the following problems.

FIG. 7 is a diagram for explaining this problem.
FIG. 7A schematically shows a tape running system in an apparatus having a rotating drum such as a VTR. The tape running path in this system is the supply side reel 8b, the rotating roller guide 9, the tension sensor guide 10, and the fixed guide 1.
The magnetic tape is wound around the rotary drum 12 on which the magnetic head 1 and the magnetic head are arranged, and the take-up reel. When the magnetic tape is wound around each of the travel path forming members and travels, the member upstream side (winding side) tension f ₁ is equal to the member downstream side (supply side) tension f ₀ due to the influence of load such as friction torque. X _s times (f ₁ = f ₀ ×
X _s ). Therefore, the tension increase rate X = X ₀ × X ₁ × X ₂ (X ₀ is each member from the supply-side reel 8b to the tension sensor guide 10 in the entire traveling route from the supply-side reel 8b to the winding-side reel 8a. , X ₁ is an increase rate from the tension sensor guide 10 to the drum entrance portion P _d , and X ₂ is an increase rate in each member from the drum entrance portion P _d to the winding side reel 8 a.

Here, for example, each increase rate is X ₀ = 1.
1, X ₁ = 1.4, X ₂ = 1.7, and supply side tension f
_{When sr} is 5 gf, the tension at the drum entrance is f _sr ×
X ₀ × X ₁ = 5 gf × 1.1 × 1.4 = 7.7 gf, and when the winding side tension f _tr is 15 gf, the tension at the drum entrance is f _tr × X ₂ ⁻¹ = 15 gf × 1 ．
7 ⁻¹ = 8.8 gf. Incidentally, of course, also the tension variation occurring in each reel, the drum inlet P _d
Then, it appears as a value obtained by multiplying each increase rate.

As described above, the tension increases between the supply-side reel and the take-up-side reel. However, the conventional control method does not consider such an increase in the tension, and the reel diameters of both reels are not taken into consideration. Since we are only considering the ratio,
As shown in FIG. 7B, the tape tension f _s ′ based on the supply-side reel control viewed from the entrance P _{d of} the drum 12 and the tape tension f _t ′ based on the winding-side reel control viewed from the entrance P _d of the drum 12. And the tape speed fluctuates. This can be expressed as follows. First, the gain distribution on both reels is determined by the supply side reel 8
b and the output torques of the motors driving the take-up reel 8a are Ms and Mt,

[0012]

[Equation 1]

[0013] Each tape tension fs', f
t'is

[0014]

[Equation 2]

## EQU1 ## Here, since X ₀ , X ₁ and X ₂ are usually larger than 1,

[0016]

(Equation 3)

It becomes In this way, if the tension increase rate is not taken into consideration, the tape will be pulled by the one with the larger tension control distribution (supply side in the above case), tape speed fluctuation will occur, and a stable tape running system will be realized. Can not.

The tension increase rate X is also related to the tape speed. Generally, as the tape speed increases, the air layer (spacing) between the magnetic tape and the travel path forming member increases. Therefore, if the tape speed changes, the apparent friction coefficient of each member decreases due to the effect of spacing, and the tension increase rate X also decreases.

Further, when reproducing a control signal such as a cue recorded on the tape during a high speed search, the rotational speed of the drum is controlled so that the relative speed between the magnetic tape and the magnetic head becomes constant, and the control is performed. A method of reproducing and detecting a signal is generally used. For example, a home digital V
According to the HD specifications defined by the "HD Digital VCR Council" as TR, the recommended drum rotation speed is 9000.
Under the conditions of rpm and drum diameter of 21.7 mm, in order to keep the relative speed constant, in the normal direction of recording and reproduction, the drum rotation speed is 9000 rpm and the forward direction (forward direction).
It is necessary to control the speed to about 15500 rpm in the 200 times search and to about 2435 rpm in the reverse direction (reverse direction) 200 times search. As described above, the rotation speed of the drum largely changes depending on the winding direction of the tape, but this affects the spacing amount in the drum, and thus the tension increase rate X in the drum changes.

As described above, in the control which does not consider the rate of increase in tension as in the prior art, it is impossible to appropriately distribute the gain in the tension control, and the speed variation due to the tension control occurs. There's a problem.

The present invention has been made to solve the above problems, and by taking into consideration the rate of increase of the tension of the take-up reel with respect to the tension of the supply reel, the tape speed caused by tension control can be improved. An object of the present invention is to provide a magnetic recording / reproducing device capable of suppressing fluctuation.

[0022]

A magnetic recording / reproducing apparatus according to claim 1, wherein a magnetic tape is run from a supply reel to a take-up reel through a drum, and a magnetic head mounted on the drum drives the magnetic tape. In a magnetic recording / reproducing apparatus for recording / reproducing information with respect to, a tension detecting section for detecting the tension of the magnetic tape, an error calculating section for calculating an error between the tension and the target tension,
An operation for correcting an error based on a winding diameter calculation unit that calculates the winding diameters of the supply-side reel and the winding-side reel, and a tension increase rate and a winding diameter that occur between the supply-side reel and the winding-side reel. An operation amount calculation unit that calculates the amount for each of the supply-side reel and the winding-side reel,
A reel motor drive unit that drives a supply-side reel motor that rotates the supply-side reel and a winding-side reel motor that rotates the winding-side reel based on an operation amount.

A magnetic recording / reproducing apparatus according to a second aspect of the present invention comprises a speed detecting section for detecting the running speed of the magnetic tape, and a speed correcting section for correcting the tension increase rate based on the running speed. .

A magnetic recording / reproducing apparatus according to a third aspect of the present invention comprises a running direction detecting section for detecting the running direction of the magnetic tape, and a direction correcting section for correcting the tension increase rate based on the running direction. is there.

According to another aspect of the magnetic recording / reproducing apparatus of the present invention, in the operation amount calculating section, at the entrance of the magnetic tape to the drum, the tension in the supply side direction of the magnetic tape is equal to the tension in the winding side direction. The operation amount is set to be calculated for each of the supply-side reel and the winding-side reel so that they are substantially the same.

The operation of the present invention will be described below.

In the magnetic recording / reproducing apparatus of the present invention, the operation amount of the tension control is distributed based on the winding diameters of the supply side reel and the winding side reel and the rate of increase in tension generated in the tape running path. In addition, the tension increase rate is corrected based on the running speed of the tape. Further, the tension increase rate is corrected based on the tape running direction. Also, the tension is balanced at the drum entrance.

As a result, the operation amount of the tension control can be appropriately distributed to the supply-side reel motor and the take-up-side reel motor, and the fluctuation of the tape speed due to the fluctuation of the tension can be suppressed and the high precision can be achieved. It can realize tape running.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION

<First Embodiment> FIG. 1 is a schematic view showing the arrangement of the main parts of a magnetic recording / reproducing apparatus according to the first embodiment of the present invention. Hereinafter, the magnetic recording / reproducing apparatus of the present embodiment will be described with reference to FIG.

In FIG. 1, a magnetic tape 13 is supplied from a supply side reel 8b and has a rotating roller guide 9, a tension sensor guide (tension detecting portion) 10, a fixed guide 11 and a magnetic head (not shown) mounted thereon. After passing through the drum unit 12, the reel 8a is wound up. The supply-side reel 8b and the winding-side reel 8a are respectively supplied-side reel motors 7 driven by reel motor drive circuits (reel motor drive units) 6b and 6a.
b, it is rotated by the operation of the winding side reel motor 7a.

The tape running as described above is controlled by the control unit 1.
Is controlled by First, the operation of the calculation unit 2 of the control unit 1 will be described.

The operation unit 2 receives the rotation speed signals 14a and 14b, which are pulse signals corresponding to the rotations of both the supply reel 8b and the take-up reel 8a, as a tape speed V.
_Tape , reel winding radii R _s and R _t , supply side reel feed forward value ff _s , and winding side reel feed forward value ff _t are calculated. Further, a speed system supply reel gain G _ds and a tension system take-up reel gain G _dt which will be described later are also calculated. The calculation part of the reel winding radii R _s and R _t of the calculation part 2 constitutes a winding diameter calculation part in the claims.

The tape speed V _tape 15 is generally calculated as follows.
The supply reel side rotation pulse period is T _t , the winding reel side rotation pulse period is T _s , and the constants are k ₁ and k ₂ .

[0034]

(Equation 4)

This is performed by the arithmetic expression represented by

Reel winding radius R of the supply side reel 8b
_s is generally k ₃ as a constant,

[0037]

(Equation 5)

It is calculated by an arithmetic expression represented by

Further, the reel winding radius R _t of the take-up side reel 8a is calculated by an equation in which _s in the above equation is replaced with _t .

The feedforward values ff _s and ff _t on the supply side and the winding side are

[0041]

(Equation 6)

It is calculated by an arithmetic expression represented by In addition,
Here, k ₄ to k ₇ are constants such as axial viscosity and inertia.

The control unit 1 performs feedforward control, tape speed control, and tape tension control using the calculation result of the calculation unit 2 described above. Hereinafter, each control method will be described.

(1) Feedforward control The feedforward values ff _s and ff _t from the calculation unit 2
Input to the reel motor drive circuits 6b and 6a, and the reel motors 7b and 7a feed feedforward values ff _s and f.
driving both reels 8a, and 8b on the basis of f _t.

(2) Speed control The adder 3 obtains the difference between the tape speed V _tape calculated by the calculation unit 2 and the speed target V _ref . Then, the speed system gain 30a multiplies the difference by the speed gain G _s to obtain the speed error V
_It is output as _err to the winding side reel motor drive circuit 6a and the multiplier 4b. Winding side reel motor drive circuit 6
A uses the speed error V _err to control the rotation of the take-up reel motor 7a. On the other hand, the multiplier 4b multiplies the speed error V _err by the speed system supply reel gain G _ds and inputs the output side speed error 21 to the supply side reel motor drive circuit 6b to rotate the supply side reel motor 7b. Take control. It should be noted that the speed system supply reel gain G _ds is set to a value that prevents an appropriate minute fluctuation due to speed control from interfering with the tension control system, and that suppresses resonance between the left and right reels and the magnetic tape 13. There is a need to. To this end, the tape accelerations on the left and right reels may be equalized to suppress the vibration of the magnetic tape 13.
That is, the speed system supply reel gain G _ds is

[0046]

(Equation 7)

It may be set as follows. Here, J _s and Jt are the inertia of each reel.

(3) Tension Control The tension sensor guide 10 senses the fluctuation of the tape tension and outputs a displacement signal to the adder (error calculation unit) 3b of the control unit 1. The adder 3b _obtains the difference between the displacement signal and the tension target f _ref, and outputs it to the tension system gain 30b. The tension gain 30b multiplies the above difference by the tension gain G _{t to} obtain the tension error f _err.
Supply side reel motor drive circuit 6b and multiplier 4a
Output to The supply-side reel motor drive circuit 6b uses the tension error f _err to supply-side reel motor 7
The rotation control of b is performed. On the other hand, the multiplier 4a multiplies the tension error f _err by the tension system take-up reel gain G _dt , and outputs the output, the take-up side tension error 25, to the take-up side reel motor drive circuit 6a, and the take-up side reel motor drive circuit 6a. The motor 7a is controlled. The tension gain 30b, the multiplier 4a, and the calculation portion of the tension take-up reel gain G _dt of the calculation unit 2 constitute the operation amount calculation unit in the claims.

Here, the tension system take-up reel gain G _dt needs to be set to an appropriate value so as to suppress the tape speed fluctuation due to the imbalance of the control ratio during the tension control by both reels. In particular,

[0050]

(Equation 8)

The value may be determined by The minus sign in the above expression means control in the direction opposite to the control direction of the supply reel motor 7b, and X is the tension f immediately before the take-up reel 8a compared to the tape f _sr immediately after the supply reel 8b. Rate at which _tr increases (rate of tension increase)
Is represented.

Here, the tension increase rate X will be described in detail. Usually, when a magnetic tape is wound around a guide or the like and travels, a value obtained by multiplying the tension on the downstream side (tape supply side) by the increase rate is the tension on the upstream side (winding side).

Here, the tension increase rate in the fixed guide 11 will be described with reference to FIG. Winding tension f ₁ when the magnetic tape 13 is wound around the fixed guide 11 at the winding angle θ and is wound in the direction of the arrow.
Is

[0054]

[Equation 9]

Is represented by Here, f ₀ is the supply tension, μ is the friction coefficient of the guide, and e is the base of the natural logarithm. That is, the tension increase rate X _s of the fixed guide is e
^μθ . Next, the tension increase rate of the rotary roller guide 9 will be described with reference to FIG. The rotary roller guide 9 is usually a fixed shaft 9a to which a rotary roller 9b is attached via a bearing or oil (not shown). When the magnetic tape 13 moves, the rotary roller 9b also rotates. It is a structure that does. The winding tension f _{1 at} this time is D
_{Let d be} the diameter of the fixed shaft, d _{d be} the friction coefficient of the fixed shaft 9a, and ignore terms such as shaft viscosity and inertia.

[0056]

(Equation 10)

Is represented by That is, the rotary roller guide 9
The rate of increase in tension is X _r .

As described above, the tension increases in various portions in the tape running path from the supply side reel 8b to the winding side reel 8c. Therefore, the tension increase rate of the entire tape running path is a value obtained by multiplying the tension increase rate of each part.

Next, the control operation when the tape is run in the magnetic recording / reproducing apparatus having the above-mentioned structure will be described. FIG. 3A is a diagram showing the tension increase rate X,
X ₀ indicates the tension sensor guide 1 from the supply side reel 8b
An increase rate of each member up to 0, X ₁ is an increase rate from the tension sensor guide to the drum entrance, and X ₂ is an increase rate of each member from the drum entrance to the winding side reel 8a. Here, the tension increase rate X of the entire tape running system is X ₀ × X ₁ × X ₂ .

At this time, the tape tension f _s by the supply-side reel control seen at the drum entrance P _d and the tape tension f _t by the take-up reel control seen at the drum entrance P _{d represent} the output torque of each motor by M. _{Let s} and M _t be

[0061]

[Equation 11]

Is as follows. Here, in a device such as a VTR,
Tension variation of the head near i.e. drum inlet P _d, by a constant tape speed variations, stable reproduction signal can be obtained. Therefore, when tension control is performed by the supply-side reel motor and the take-up-side reel motor, the tension at the drum entrance P _d is f _{s when} viewed at the drum entrance.
Under the condition of = f _t , the magnetic tape is prevented from being pulled to one side by the tension control, and the speed variation due to the tension control does not occur. This state is shown in FIG. However, in the figure, f _s and f _t
The length of the arrow indicates the tension value. Here, the gain distribution to both reels to satisfy the above condition (f _s = f _t ) is

[0063]

(Equation 12)

Therefore, the control gain, that is, the gain distribution, in the take-up reel 8a with respect to the supply reel 8b is
As described above, the tension system take-up reel gain G _dt may be set. In the above formula, the directions of tension and torque are also taken into consideration, and the minus sign in the formula indicates that the tension direction and torque direction on the supply side and the winding side are opposite.

The tension system take-up reel gain G _dt, that is, the gain distribution is a value that not only suppresses the speed fluctuation of the drum entrance portion P _d , but is also valid at any place of the tape running system.

As described above, in the present embodiment, since the gain distribution for the tension control is performed in consideration of the tension increase rate, the tape speed does not fluctuate due to the tension control, and highly accurate tape running can be realized. You can

<Second Embodiment> The magnetic recording / reproducing apparatus according to the second embodiment has the following features in the gain distribution of the tension control system in the magnetic recording / reproducing apparatus according to the first embodiment.
This is to consider the effect of spacing caused by the change in tape speed.

FIG. 4 is a schematic diagram showing the structure of the main part of the magnetic recording / reproducing apparatus according to the second embodiment. FIG.
In FIG. 2, the same parts as those in FIG.

The tape system take-up reel constant G _dt1 output from the arithmetic unit 2 is the same value as the tension system take-up reel gain G _dt described in the first embodiment.

Speed proportional gain calculating section (speed correcting section) 26
The tension system take-up reel constant G _dt1, and the function k _sp receiving tape speed V _tape, represented the tension system take-up reel constant G _dt1 tape speed V _tape
It is converted into a value proportional to (V _tape ) and output. That is,
The following tension system take-up reel gain G _dt 'is output.

[0071]

(Equation 13)

Then, by using this tension system take-up reel gain G _dt ′, tension control is performed in the same manner as in the first embodiment.

By the way, normally, when the tape runs at a high speed, inflow (spacing) of air occurs at a portion around the magnetic tape 13 such as the tape guides 11 and 9 and the drum unit 12, so that the contact pressure to the guide is increased. The apparent friction coefficient becomes smaller. Therefore, the rate of increase in tension decreases. Actually, when the tape speed magnification by the high speed search changed from 25 times to 200 times, the tension increase rate decreased from 3.5 to 1.8.

In the present embodiment, the function k _sp (V
_tape ) is used. That is, the function k _sp (V
_tape ) is set to a function such that the magnitude of the tension system take-up reel gain G _dt 'becomes smaller as the tape speed increases. Therefore, the velocity proportional gain calculation unit 2
6 can output the tension system take-up reel gain G _dt ′ that well follows the fluctuation of the tension increase rate due to the change of the tape speed.

As described above, according to the magnetic recording / reproducing apparatus of the present embodiment, the tension system take-up reel gain which well follows the tension increase rate is generated even when the tape speed is switched and the tape is run. be able to. Therefore, it is possible to further suppress the tape speed fluctuation due to the gain distribution imbalance.

<Third Embodiment> In the magnetic recording / reproducing apparatus of the third embodiment, in the tape distribution in the tape running direction in the gain distribution of the tension control system in the magnetic recording / reproducing apparatus of the first and second embodiments. The effect of is taken into consideration.

FIG. 5 shows the configuration of a magnetic recording / reproducing apparatus in which a traveling direction gain calculating section (direction correcting section) for changing the tension increase rate according to the tape traveling direction is added to the magnetic recording / reproducing apparatus of the first embodiment. It is a schematic diagram showing. However, FIG.
In FIG. 1, the same parts as those in FIG.
The description is omitted.

The tension system take-up reel gain constant G _dt1 output by the calculation unit 2 is the same value as the tension system take-up reel gain G _dt described in the first embodiment.

The running direction gain calculating section 27 receives the tension system take-up reel gain G _dt and the tape running direction signal s _dir from the computing section 2 and sets the tension system take-up reel constant G _dt1 to the tape running direction s. It is converted into a value proportional to the function k _dr (s _dir ) represented by _dir and output.
That is, the following tension system take-up reel gain G _dt ″ is output.

[0080]

[Equation 14]

By the way, normally, at the time of reproducing by the magnetic recording / reproducing apparatus, the signal frequency reproduced by making the relative speed of the magnetic tape 13 and the magnetic head constant is made constant. The rotation speed of the drum unit 12 is changed. Therefore, the spacing of the magnetic tape 13 in the drum unit 12 is
It changes depending on the tape running direction. Therefore, the tension increase rate in the drum unit 12 also changes in the tape running direction, and the tension increase rate of the entire tape running system also changes. According to the actual measurement, when traveling at the same speed in both forward and reverse directions (search at 200 times speed), the tension increase rate is 1.500 at the drum rotation speed of 15500 rpm in the forward direction (arrow in the figure).
8 and 2.6 in the reverse direction at a drum rotation speed of 2435 rpm.

The magnetic recording / reproducing apparatus of the present embodiment uses the function k _{dr in} order to correct the fluctuation of the tension increase rate.
(S _dir ) is used. This function is set to change the tension system take-up reel gain G _dt ″ according to the running direction of the tape. Specifically, the tension system take-up reel gain G _dt ″ is set to be larger when the tape running direction is the reverse direction than when the tape running direction is the positive direction. This allows
It is possible to perform the tension control adapted to the tension increase rate irrespective of the running direction of the tape, and it is possible to further suppress the speed fluctuation of the tape.

FIG. 6 is a schematic diagram showing the construction of a magnetic recording / reproducing apparatus in which a traveling direction gain calculating section for changing the tension increase rate depending on the tape traveling direction is added to the magnetic recording / reproducing apparatus of the second embodiment. However, in FIG. 6, the same parts as those in FIG. 4 are designated by the same reference numerals, and the description thereof will be omitted.

The tension system take-up reel constant G _dt1 output from the arithmetic unit 2 is the same value as the tension system take-up reel gain G _dt described in the first embodiment.

Tape speed / running direction gain calculator 29
The tension system take-up reel gain G _dt, tape running direction signal s _dir, using a tape speed V _tape, functions tension system take-up reel gain G _dt k _ds (V _tape,
The tension system take-up reel gain G _dt ″ ″ obtained by multiplying by s _dir ) is output. Where k _ds (V
_tape , s _dir ) indicates that k _ds is a function of s _dir , V _tape . The tension system take-up reel gain G _dt '''is as follows.

[0086]

(Equation 15)

The above function k _dr (V _tape , s _dir )
Is a function for correcting the fluctuation of the tension increase rate depending on the tape speed and the tape running direction. This makes it possible to perform tension control adapted to the rate of increase in tension regardless of the tape speed and tape running direction, and further suppress tape speed fluctuations.

Incidentally, in FIGS. 1, 4, 5, and 6 in the first to third embodiments, the capstan motor, which is less related to the reel traveling, is ignored, and compared with the actual traveling system. The number of guides is also omitted.

Further, in each of the embodiments, the tape speed is calculated from the reel rotation pulse, but a speed detector may be provided in the tape traveling path to directly detect the tape speed.

Further, the tape running direction is the direction of the arrow in the figure, but the tape running direction is not particularly limited to this, and when running in the opposite direction, 8a is the supply reel and 8b is the take-up reel.

Further, in each embodiment, in the calculation of the tension increase rate, the terms unrelated to the tape speed and the tape running direction are neglected because they are substantially very small. To the rate of tension increase,
It suffices to add them in an offset manner.

Further, although these configurations may be configured by circuits in hardware, they can be downsized and simplified by performing them in software using a microcomputer or the like. Further, the above-mentioned constants and the like are made into a table on a memory and called with the corresponding parameters, whereby the calculation time can be shortened.

[0093]

As described above, in the present invention, since each reel is driven based on the tension increase rate, it is possible to suppress fluctuations in the tape speed that occur in the tension control system, and to stably run the tape. Can be made.

Further, by correcting the fluctuation of the tension increase rate depending on the tape speed and the tape running direction, the fluctuation of the tape speed can be suppressed more reliably.

Further, since the tension is balanced at the drum entrance, fluctuations in the relative speed of the magnetic tape with respect to the magnetic head can be eliminated.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a main configuration of a magnetic recording / reproducing apparatus according to a first embodiment.

FIG. 2 is a diagram illustrating a tension increase rate by a guide.

FIG. 3 is a diagram illustrating an effect of the present invention.

FIG. 4 is a schematic diagram showing a configuration of a main part of a magnetic recording / reproducing apparatus according to a second embodiment.

FIG. 5 is a schematic diagram showing a configuration of a main part of a magnetic recording / reproducing apparatus according to a third embodiment.

FIG. 6 is a schematic diagram showing another configuration of the main part of the magnetic recording / reproducing apparatus of the third embodiment.

FIG. 7 is a diagram illustrating a problem of a conventional magnetic recording / reproducing device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 control part 2 calculation part 3a, 3b, 5a, 5b adder 4a, 4b multiplier 6a winding side reel motor drive circuit 6b supply side reel motor drive circuit 7a winding side reel motor 7b supply side reel motor 8a winding side Reel 8b Supply-side reel 9 Rotating roller guide 10 Tension sensor guide 11 Fixed guide 12 Drum unit 26 Speed proportional gain calculator 27 Travel direction gain calculator 29 Tape speed / travel direction gain calculator f _err Tension error G _dt , G _dt ', G _dt ″, G _dt ″ '' Tension system take-up reel gain s _dir Tape running direction V _tape Tape speed

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mitsunobu Yoshida 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation

Claims (4)

[Claims] 1. A magnetic recording / reproducing apparatus in which a magnetic tape is run from a supply-side reel to a winding-side reel through a drum, and information is recorded / reproduced on / from the magnetic tape by a magnetic head attached to the drum. A tension detecting unit that detects the tension of the magnetic tape; an error calculating unit that calculates an error between the tension and the target tension; a winding diameter calculation that calculates the winding diameters of the supply-side reel and the winding-side reel. Section, the rate of increase in tension generated between the supply-side reel and the winding-side reel, and the winding diameter, the operation amount for correcting the error is set to the supply-side reel and the winding-up reel. An operation amount calculation unit for calculating each of the supply reels, and a supply reel for rotating the supply reel based on the operation amount. Magnetic recording and reproducing apparatus characterized in that it comprises a reel motor driving unit for driving the motor and the take-up side reel motor for rotating said take-up reel, the. 2. A speed detecting unit that detects a running speed of the magnetic tape, and a speed correcting unit that corrects the tension increase rate based on the running speed. The magnetic recording / reproducing apparatus described. 3. A traveling direction detection unit that detects a traveling direction of the magnetic tape, and a direction correction unit that corrects the tension increase rate based on the traveling direction. Alternatively, the magnetic recording / reproducing apparatus described in 2. 4. The operation amount calculation unit is configured such that, at the entrance of the magnetic tape to the drum, the tension in the supply side direction of the magnetic tape is substantially the same as the tension in the winding side direction. The magnetic recording / reproducing apparatus according to any one of claims 1 to 3, wherein the operation amount is set to be calculated for each of the supply-side reel and the winding-side reel.