JPH0479057A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To accurately control traveling speed and tension by providing a supply reel driving means to be controlled in order to make the tension of a magnetic tape constant and a take-up reel driving means to be driven in accordance with set take-up reel driving torque and a speed error detecting output. CONSTITUTION:The tension is controlled in such a manner that a data outputted from a supply reel rotation detecting means 14 is given to a supply side winding diameter detecting means 113 and a tape tension control torque calculating means 114, whereas a supply reel winding diameter is detected by the supply side winding diameter detecting means 113, and this detecting result is given to the tape tension control torque calculating means 114, so that a supply reel driving means 112 is controlled by this calculating result. Then, the magnetic tape traveling speed is controlled in such a way that take-up driving torque required for making the tape speed constant is set by a take-up reel driving torque setting means, and a magnetic tape traveling speed is calculated by a speed detecting means 109, and the take-up reel driving means 112 is controlled in accordance with these factors. By this method, the magnetic tape traveling speed and tension are controlled with high accuracy.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetic recording and reproducing device, and particularly to a magnetic recording and reproducing device that can control the running speed and tension of a magnetic tape at a constant level. Specifically, the present invention relates to tape feeding control of a so-called reel-to-reel magnetic tape device that does not use a capstan.

[Prior Art] In order to perform accurate and high-density recording and reproduction in a magnetic recording and reproducing device using magnetic tape, it is necessary to keep the running speed of the magnetic tape constant and to keep the tension applied to the magnetic tape constant. It won't happen. For this reason, conventional magnetic recording and reproducing devices keep the running speed of the magnetic tape constant by, for example, pressing and driving the magnetic tape using a capstan and a pinch roller. Additionally, tape tension was controlled using a tension detection mechanism called a tension arm.

However, in the conventional magnetic recording/reproducing device mentioned above,
The running speed of the magnetic tape is controlled by a capstan, and the tension is controlled at a constant level by a mechanism using a tension arm, so when the running speed of the magnetic tape becomes high, the running speed can be accurately controlled. Not only is this not possible, but resonance may occur between the magnetic tape and the tension arm. Another problem is that the overall structure becomes complicated.

Therefore, a method of directly transferring the tape from reel to reel without using Moyapustan is being considered. At this time, the tape speed is determined by detecting the rotation period of the rotating speed detection roller and reel, determining the error from the preset period, and amplifying this and applying it to the reel drive motor. , it is conceivable to configure the system to perform feedback control. Further, the tape tension may be configured to, for example, detect the reel winding diameter and apply a torque corresponding to this to the supply reel.

[Problems to be Solved by the Invention] However, the above tape speed control has the following problems. In other words, speed control is performed by feeding back the error between the detected speed and the reference speed, or in the case of a reel-to-reel running system, the gain of the control loop cannot be set high due to resonance between the reel and the tape.
Therefore, there was a problem that highly accurate control could not be performed.

Therefore, the main object of the present invention is to provide a magnetic recording and reproducing device that can accurately control the running speed and tension even when the gain cannot be increased in the reel-to-reel running system.

[Means for Solving the Problems] The present invention is a magnetic recording and reproducing device that runs a magnetic tape while keeping the running speed of the magnetic tape and the tension applied to the magnetic tape constant. a rotating roller that rotates, a speed detecting means that detects the running speed of the tape according to the rotation of the rotating roller, a speed error detecting means that compares the detected running speed with a reference speed that should be a reference, and a magnetic A supply reel rotation detection means for detecting the rotation of the supply reel as the tape runs, a supply reel winding diameter detection means for calculating the winding diameter of the supply reel based on the detection result and the tape speed, and the detection result. tape tension control torque calculation means for calculating the drive torque of the supply reel according to the calculation result; supply reel drive means for controlling the tension of the magnetic tape to be constant according to the calculation result; and supply reel winding diameter detection means. a take-up reel drive torque setting means for setting a take-up reel drive torque to keep the running speed of the magnetic tape constant according to the detection output of the take-up reel drive torque setting means; and a take-up reel drive torque set by the take-up reel drive torque setting means. and a take-up reel drive means that is driven in accordance with the detection output of the speed error detection means.

[Function] The magnetic recording/reproducing apparatus according to the present invention controls the tension and the running speed of the magnetic tape. To control the tension, data output from the supply reel rotation detection means is given to the supply side winding diameter detection means and the tape tension control torque calculation means, and the data indicating the rotation of the rotating roller is guided to the supply side winding diameter detection means. . The supply side winding diameter detection means detects the winding diameter of the supply reel, and provides the detection result to the tape tension control torque calculation means, and the supply reel driving means is controlled based on the second calculation result.

Further, the running speed of the magnetic tape is controlled by setting the take-up drive torque necessary to keep the tape speed constant according to the output of the supply side winding diameter detection means, or by the take-up reel drive torque setting means. Data indicating the rotation of the rotary roller is guided to speed detection means, which is configured to calculate the running speed of the magnetic tape, and the take-up reel drive means is controlled in accordance with the results of both calculations.

[Embodiment 1 of the Invention] An embodiment of the magnetic recording/reproducing apparatus according to the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a block diagram for controlling the running speed and tape tension of a magnetic tape in an embodiment of the present invention, and FIG. 2 illustrates a motor drive signal for controlling the tape speed in an embodiment of the present invention. This is a diagram for

The magnetic recording/reproducing apparatus for a data streamer shown in FIG. 1 is basically configured to record or reproduce a large amount of data on a magnetic tape 2 of a cassette 1 at high speed. The main body of the magnetic recording/reproducing device has an automatic cassette loading mechanism (
(not shown) is installed. The reels 3 and 4 of the cassette 1 automatically loaded by the cassette automatic loading mechanism are rotationally driven by a reel drive mechanism as described below. That is, the reel drive mechanism is installed below the main chassis (not shown) corresponding to the position below the loaded cassette 1, and is mainly composed of reel motors 910 each fixed to the main chassis. There is.

Each of the eight axes of reel motors 9 and 10 has an FG.
A disk (not shown) is connected. Then, when the cassette 1 is loaded, the driving force of the reel motors 9 and 10 is independently transmitted to the respective reels 3 and 4.

Each of the FG disks is a disk in which a plurality of slits are formed at equal pitches on the periphery, and a photointerrupter (not shown) is arranged at the opening position of each of the slits. In other words, the rotational speed of the FG disk is detected as the rotational speed of the reel 34 or the pulse output of the photointerrupter 14, 15, respectively. The magnetic head 74 is disposed between the guide rollers 56 and 57, contacts the magnetic tape 2 to record data, and reproduces the recorded data.

In FIG. 1, the running direction of the magnetic tape 2 is A.

When the tape is running in direction A, reel 3 is used for supply and reel 4 is used for winding. On the other hand, when the tape running direction is B, reel 3 is used for winding, and reel 4 is used for supply. First, a control system for the running speed of the magnetic tape 2 will be explained. The running speed V of the magnetic tape 2 is expressed by the following equation (1).

v=2 πRt/T= ・(1> Ro is the radius of the kite roller 32, and T6 is the rotation period of the kite roller 32. Photo interrupter 5
1, when the kite roller 32 rotates once, the FG signal 51a
N F G Ro pulse signals are output as follows. This FG signal 51a is a signal giving the rotation period T6 of the guide roller 32, and is given to the speed detection circuit 109. Note that the period of the FG signal 51a is assumed to be TFG RE. In addition, the time nav" for dividing the FG signal 51a by nav"
TpThe periods T counted between GREs. The number of pulses of the K reference clock signal (speed reference data of the magnetic tape 2 given by the output signal 116a of the crystal oscillator 116) is n. When CK is assumed, the following equation (2) holds true.

nc CK ・T()(=nav −TpcRt・・
- (2) Also, the rotation period T6 of the guide roller 32 is the (
3) It is expressed by the formula.

To=NF6R0·T, 6R, (3) Therefore, the following equation (4) is established from equations (1), (2), and (3).

V= (2πRE/NFc*p) (na,/Tc
K ) (1/ nc CK ) − (4) Therefore, the number of pulses n. Detect CK and send the detection result to step (4)
By substituting into the equation, the running speed V of the magnetic tape 2 can be calculated. Since the values other than ncCK on the right side of equation (4) are constants, the number of pulses is n. By controlling CK to a constant value, the running speed V of the magnetic tape 2 can be kept constant.

The running speed V of the magnetic tape 2 obtained by substituting the number of pulses of the reference clock signal detected in each nav-divided cycle of the FG signal 51a mentioned above into equation (4) and the speed reference target value. The difference is detected by speed error detection circuit 110. That is, the speed error detection circuit 110 calculates the output signal 11 of the crystal oscillator 116 from the running speed data of the magnetic tape 2 given by the output signal of the speed detection circuit 109.
The circuit configuration is such that the reference speed data of the magnetic tape 2 given by 6a is subtracted, and the result of this subtraction becomes speed error data.

Now, the take-up reel drive torque MT required to keep the tape speed constant can be determined as follows. That is, when the torque generated by the take-up motor is equal to the sum of the additional torque due to the tape tension and the torque loss, the tape speed becomes constant. That is, assuming that the target tape tension is F (constant) and the winding diameter of the take-up reel is R, the following equation (5) holds true.

MT=RT-F+Mo-(5) However, MO is a torque loss in the take-up reel shaft, etc., and is set in advance. On the other hand, the output of the supply reel winding diameter detection circuit 113, which will be explained in detail later, gives the winding diameter of the supply reel.In this case, the reel winding diameter on the take-up side can be determined by the following equation (6). . That is, if the radius of the supply reel is R5, then RT=ET1T (6) where S is a constant determined by the tape length and thickness. Therefore, by equations (5) and (6), if the supply reel winding diameter R5 is given, the winding torque M for keeping the tape speed constant can be determined. Furthermore, if the torque constant of reel motor 9.10 is KM, then
The following equation (7) holds true.

V, = R/KM-MT+KM ・ω (7) where vM is the motor terminal voltage, R is the motor coil winding resistance, and ω is the motor rotational angular velocity. ω is ω=v
/R7 and using equation (5), equation (7) becomes the following equation (8).

VM=R/KM'(R7'F+Mo)+KM
” V/RT...(8) That is, if the take-up reel winding diameter R is determined by equation (6), then the take-up reel motor's The drive voltage V is calculated.

The take-up reel drive torque calculation circuit 117 shown in FIG. The reel drive voltage vM signal is configured to be output.

The output of the take-up reel drive torque calculation circuit 117 and the output of the aforementioned speed error detection circuit 110 are added by a compensation circuit 111 and provided to the reel motor drive circuit 112. The compensation circuit 111 is a phase compensation circuit for stabilizing the speed control system. The reel motor drive circuit 112 includes the compensation circuit 11
The reel motors 9 and 10 are configured by driver circuits that generate electric power for respectively driving the reel motors 9 and 10 according to the error speed data processed by the reel motors 9 and 10. A switch 108 is provided between the reel motor drive circuit 112 and the reel motor 9.10, and is switched alternately depending on the setting of the tape running direction.

In FIG. 1, A
, B correspond to the settings of the tape running directions A and B. The same applies to switches 106 and 107, which will be described later.

In other words, when the contact of the switch 108 is switched to the A side, the reel 4 becomes the take-up reel, so
The output power of the reel motor drive circuit 112 is supplied to the reel motor 10, which is a take-up reel drive means, and the magnetic tape 2 is wound from the reel 3 to the reel 4 by this rotational driving force. In contrast, switch 108
When the contact is switched to the B side, the reel 3 becomes the take-up reel, so the reel motor drive circuit 112
The output power is supplied to the reel motor 9, and the magnetic tape 2 is wound from the reel 4 to the reel 3 by this rotational driving force. By the closed loop speed control system configured as described above, the running speed of the magnetic tape 2 is constant controlled to the reference speed described above. In addition, the number of pulses is nc. Since the sampling period Tvs□9° is detected every time [nav ・TFORE], the sampling period Tvs□9° is the following (9th
) is expressed by the formula.

Tvsmllll = nav - TFaRE - (9) Therefore, since the sampling period T v a m p 1 that determines the responsiveness of the control of the running speed of the magnetic tape 2 is proportional to the frequency division ratio nav, this frequency division ratio n8, The responsiveness of the control can be improved by reducing the . Further, equation (4) can be transformed as shown in equation (10) below.

nccK= (2πRE/NFGRE) (nav
/TCK) (1/v)-(10) In other words, the number of pulses ncc of the reference clock signal is proportional to nav, so the quantization error can be reduced by increasing nav. As described above, since the control responsiveness and quantization error change depending on the size of nav, it is necessary to select an appropriate value of nav using equations (9) and (10).

Next, a control system for keeping the tape tension of the magnetic tape 2 in contact with the magnetic head 74 constant will be described. Photo interrupter 14.15 as supply reel rotation detection means
The FG signals 14a and 15a respectively outputted from the FG signals 14a and 15a include data on the rotation period (Ts) of the reels 3 and 4, respectively, and these signals 14a and 15a are used to detect the winding diameter on the supply side via the switch 106. The signal is applied to circuit 113 and tape tension control torque calculation circuit 114 . In addition, the FG output from the photo interrupter 51
As already mentioned, the signal 51a includes data on the rotation period TE of the guide roller 32, and is also provided to the supply side winding diameter detection circuit 113 in addition to the speed detection circuit 8 circuit 109.

The supply side winding diameter detection circuit 113 detects the tape winding radius (R
The circuit configuration is such that each of the values (denoted as s) is calculated by the method described below.

The relationship between the rotation period Ts of the reel 3.4, the tape winding radius Rs, and the running speed V of the magnetic tape 2 is expressed by the following equation (11).

v=2πRs/Ts-(11) When V is eliminated from the above equations (1) and (11),
The following equation (12) is obtained.

Rs = RE-T S/TE - (12) In the supply side winding diameter detection circuit 113, a photo interrupter 51 has a period T.
The FG signal 51a of FGRE is given, and
F from the photo interrupter 14 via the switch 106
A G signal 14a is provided. Note that the photo ink club 14 is set to output NFGS FG signals 14a having a period of TFGS every time the reel 4 rotates once. Therefore, the rotation period Ts is expressed by the following equation (13).

T S ”NF c s ・TF G SHere, if the number of times the FG signal 51a with the period TFGRE is counted during the time na7-Tpcs is n.Ro, then the following (14)
The formula holds true.

nc RE 6TrciE=na70TFc s゛=
(1 Therefore, equation (3), equation (12), equation (13)
) and equation (14), the following equation (15) holds true.

Rs= (NFGS/NFGRE) (RE/na
T)·nc RE −(15) Therefore, by measuring noRE, the winding diameter Rs of the reel 4, which is the supply reel, can be detected. In other words, the FG signal 14a with period TFGS is set to na7.
The number of pulses of the FG signal 51a is measured for each divided period, and this is calculated as n. The winding diameter Rs of the reel 4 is calculated by substituting RE into equation (15). Supply side winding diameter detection circuit 11
3 is output to the tape tension control torque calculation circuit 114.

The tape tension control torque calculation circuit 114 calculates the reel driving torque (this is assumed to be Ms) necessary to maintain the tape tension (this is assumed to be F) which is a target value that is preset based on the data of the tape winding radius Rs. ) is calculated according to the following equation (16). Note that ML is l·le cross due to viscous resistance of a bearing (not shown). The tape tension F in a steady state can be expressed by the following equation (16).

F= (Ms+ML)/R3...(16) Torque ML
is the viscous resistance MLR of the reel bearing and other guides (guide rollers 3.1, 33, 34, 56, 57, etc.)
The viscous resistance and frictional resistance ML. It can be broadly classified into. The viscous resistances M and R of the reel bearing are proportional to the rotational speed of the reel, so if the viscosity coefficient is DLR, then the (17th)
It can be expressed by the formula.

ML R=Dt, R·2 π/T s-(17) Therefore, the equation (16) is transformed into the following equation (18).

F − (MS + ML o + DL R・2π/Ts
)/R5 (18) M in equation (18) is expressed by the following equation (19).

Ms=F-Rs-MLo-DLR・2yr/, T S
...Equation (19) is a steady state relational expression, but it takes into account the tape tension F and the viscous resistance of the guides.

While data on the frictional resistance ML0 is set in advance, the reel driving torque Ms is calculated by substituting the tape winding radius Rs of the reel 4 into equation (]9).

This calculation result is led to the reel drive circuit 115, where a current necessary to obtain the reel drive torque Ms is generated and supplied to the reel motor 9.10 via the switch 107. That is, when the tape running direction is set to A, the contact of the switch 107 becomes A, and the output current of the reel drive circuit 115 is supplied to the reel motor 9, which is the supply reel drive means, while the tape running direction is set to B.
When this is the case, the contact point of the switch 107 becomes B, and the output current of the reel drive circuit 115 is supplied to the reel motor 10.

With the tape tension control system configured as described above,
The tape tension of the magnetic tape 2 is always controlled to the above-mentioned value of F, regardless of the setting of the tape running direction. At the same time, when the running speed of the magnetic tape 2 is controlled, stable running of the magnetic tape 2 is realized.

Note that although electronic circuits are used here to realize the functions of the present invention, it goes without saying that these may be configured by software using a computer.

Also, a reel drive circuit 11 that drives the aforementioned take-up reel.
2 is configured as a current feedback type, since the take-up reel is torque-controlled, the take-up reel drive torque calculation circuit 11
The output of 7 may be configured to include 8 pieces of MT data based on equation (5).

[Effects of the Invention] As described above, the present invention has a simple reel-to-reel magnetic tape running system without using a capstan or a tension detection mechanism such as a tension arm. Even if the feedback gain for speed detection cannot be increased, the running speed of the magnetic tape can be kept stable and constant, and the tension applied to the magnetic tape can be kept constant, resulting in a simple structure and high accuracy. It is possible to control the running of the magnetic tape with high speed.

[Brief explanation of drawings]

FIG. 1 is a block diagram for controlling the running speed and tape tension of a magnetic tape in an embodiment of the present invention. FIG. 2 is a diagram for explaining a motor drive signal for tape speed control according to an embodiment of the present invention. In the figure, 2 is a magnetic tape, 14, 15.51 is a photointerrupter, 31, 32, 33, 34, 56.57
1 is a guide roller, 74 is a magnetic head, 109 is a speed detection circuit, 110 is a speed error detection circuit, 113 is a supply side winding diameter detection circuit, 114 is a tape tension control torque calculation circuit, 117 is a take-up reel drive torque calculation 8 circuit shows.

Claims (1)

[Scope of Claims] A magnetic recording and reproducing device that runs a magnetic tape supplied from a supply reel and wound onto a take-up reel while keeping constant the running speed of the magnetic tape and the tension applied to the magnetic tape, comprising: a rotating roller that rotates as the magnetic tape runs; a speed detecting means that detects the running speed of the magnetic tape according to the rotation of the rotating roller; and a speed detected by the speed detecting means that serves as a reference. speed error detection means for comparing the speed with a reference speed; supply reel rotation detection means for detecting the rotation of the supply reel as the magnetic tape runs; and detection results of the supply reel rotation detection means and the speed detection means. supply reel winding diameter detection means for calculating the winding diameter of the supply reel according to the tape speed detected by the supply reel winding diameter detection means; and calculating the driving torque of the supply reel according to the detection result of the supply reel winding diameter detection means. tape tension control torque calculation means; supply reel driving means controlled to keep the tension of the magnetic tape constant according to the calculation result of the tape tension control torque calculation means; and detection by the supply reel winding diameter detection means. a take-up reel drive torque setting means for setting a take-up reel drive torque to keep the running speed of the magnetic tape constant according to the output; and a take-up reel drive set by the take-up reel drive torque setting means. A magnetic recording and reproducing device comprising a take-up reel drive means driven in accordance with torque and a detection output of the speed error detection means.