JP2004234721A - Tape drive - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tape drive which can realize FF/REW quicker than before even if it is a tape drive which cannot make power source voltage high. <P>SOLUTION: Speeding up of tape transfer speed is achieved; by setting up a lead angle setting means 20 and performing setting of the lead angle in accordance with the tape speed information supplied from a terminal 21 when energizing switching of a coil 15 is performed according to a rotor position detecting means 17 of a reel motor; and by reducing counter electromotive voltage of a reel motor by making it operate so that a reel motor torque constant may become lower when a tape is transferred at a high speed. The concerted operation between both reels can be performed smoothly by setting the lead angle of reel motors of a rolling up side and a supply side simultaneously. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a tape drive, and more particularly, to speeding up fast forward / rewind of a tape drive.
[0002]
[Prior art]
VTRs are well known as a tape drive for recording and reproducing video information, audio information, and data. However, since these tape drives do not allow random access, fast forward / rewind (hereinafter referred to as FF / REW). It is desired to do so.
[0003]
The following is known as a conventional tape drive device.
[0004]
A VTR, which is an example of a conventional tape drive, is configured as shown in FIG. 3 (for example, see Patent Document 1). The magnetic tape 100 is driven by engaging with an S reel 1 which is a supply side reel of the tape cassette and a T reel 8 which is a take-up side reel of the tape cassette. The magnetic tape 100 pulled out from the S reel of the tape cassette is loaded on the cylinder 10 and wound on the T reel of the tape cassette. Arrows indicate the running direction of the magnetic tape 100 and the rotation direction of the reel during normal recording and reproduction.
[0005]
At the time of REW, the S reel motor of the S reel 1 is driven. The REW tape speed control of the S reel 1 is performed as follows. From the tape speed command information V supplied from the system control means (not shown), the S reel target speed Sr corresponding to the speed is calculated, and the S reel rotation speed Ss actually detected by the S reel winding diameter detecting means 6 is calculated. The S reel speed control means 3 compares the S reel target speed Sr with the S reel target speed Sr. Then, the speed error information (Sr-Ss) is calculated so that the S reel rotation speed Ss approaches the S reel target speed Sr, and the S reel corresponding to the speed error information (Sr-Ss) via the S reel driving means 4. The motor torque is supplied to the S reel 1.
[0006]
The S reel target rotation speed calculation means 5 obtains the S reel target speed Sr by dividing the tape speed command information V by the S reel radius RS calculated by the S reel winding diameter detection means 6. The S-reel radius RS can be calculated from the tape total amount information 7 and the rotation speed information 9s and 9t of the S and T reels 1 and 8, as is known.
[0007]
The cylinder 10 at the time of REW can reproduce data by controlling the rotation speed to be different from that at the time of recording. This control is called relative speed correction. In FIG. 3, the tape speed command information V supplied from the system control unit is also supplied to the cylinder speed control unit 11, and a cylinder target rotation speed corresponding to the tape speed is calculated. The difference information between the cylinder target rotation speed and the cylinder rotation speed Hs actually detected by the cylinder rotation speed detection means 12 is supplied to the cylinder drive means 13 and the cylinder rotation speed is controlled to the target speed.
[0008]
Here, the number of rotations of the S reel motor at the time of REW of the S reel 1: S torque characteristic (hereinafter referred to as ST characteristic) is as shown in FIG. When the rated voltage is applied to the S reel motor, the vertical axis shows the motor rotation speed [rpm] and the horizontal axis shows the motor generated torque [gr · cm]. The intersection indicates the generated torque Tmax at the time of motor lock, and the intersection of the y-axis indicates the motor rotation speed Smax under no load. If the applied voltage supplied to the motor decreases, the characteristic (1) has the same slope but changes like the characteristic (3).
[0009]
Hereinafter, the S reel side during the REW will be considered. The take-up tape speed is controlled to be constant until the take-up tape tension is constant and the tape diameter of the T-reel 8 is reduced from the start of the REW until the tape speed approaches the start of the tape and slows down as shown in FIG. , The ST characteristic when the voltage applied to the S reel motor is constant is as shown in (2).
[0010]
Therefore, it is necessary to supply the applied voltage so as to include the characteristic (1) and secure the dynamic range. In the conventional VTR shown in FIG. 4, the dynamic range margin A at the beginning of rewinding (hereinafter, the dynamic range margin is referred to as torque margin) A of the characteristic (2) is smaller than the torque margin B at the end of winding.
[0011]
It should be noted that the above-mentioned ST characteristic changes when the motor used differs, so that the tape speed, the control tension value, the shape of the tape cassette used (hub diameter, maximum diameter) even when the motor used is the same. 6 (a) and 6 (b) depending on the difference.
[0012]
FIG. 6A shows the ST characteristic when the torque margin A at the start of REW is larger than the torque margin B at the end of winding, and FIG. 6B shows the torque margin A at the beginning and end of winding at the REW. Also shows the ST characteristic when the torque margin C in the middle part is large.
[0013]
In the VTR, the tape tension is controlled to be constant and the tape speed is also controlled to be constant during the REW from the viewpoint of stable data reproduction and tape protection.
[0014]
[Patent Document 1]
JP 2000-322791 A
[Problems to be solved by the invention]
In a portable use device used outdoors, a battery is often used as a power source. In this case, the maximum power supply voltage supplied to the device is often restricted and cannot be set to a high voltage. In addition, since the voltage of semiconductor devices has been reduced in recent years, the voltage of power supplies provided in equipment has also been reduced. For this reason, the power supply voltage supplied to the tape drive is inevitably restricted, making it difficult to increase the number of revolutions of the motor, and also increasing the tape speed in FF / REW. Especially when trying to achieve power saving by reducing motor power consumption, if a motor with good torque efficiency is used, the motor back electromotive voltage will also increase, making it increasingly difficult to increase the motor speed. It has become.
[0016]
SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to increase the FF / REW speed in a tape drive device having a low power supply voltage.
[0017]
[Means for Solving the Problems]
In order to solve the above problems, the present invention can detect a rotor position of a reel motor when a tape is transferred at high speed, and can set a plurality of types of coil energization switching timings according to the rotor position and the tape transfer speed information. This is a configuration provided with a lead angle setting means.
[0018]
As a result, it is possible to suppress an increase in the back electromotive voltage of the reel motor during the high-speed transfer of the tape, and it is possible to realize an increase in the tape transfer speed.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
According to a first aspect of the present invention, there is provided a tape driving device for driving a reel motor to transfer a tape, wherein a rotor position detecting means for detecting a rotor position of the reel motor and a tape transfer speed information are detected. And a lead angle setting unit that sets a plurality of types of coil energization switching timings according to at least one of the rotor position and the tape transfer speed information. Yes, the rise of the reel motor back electromotive voltage during high-speed tape transfer can be suppressed, the restriction on the maximum rotation speed of the reel motor, which was limited by the power supply voltage of the equipment, can be relaxed, and the FF / REW speed can be increased. It has the effect that it becomes possible.
[0020]
According to a second aspect of the present invention, there is provided the tape drive device according to the first aspect, wherein the lead angle setting means sets coil energization switching timing using fast-forward / rewind mode information. Also has the effect that the FF / REW speed can be increased.
[0021]
The invention according to claim 3 further includes an S reel motor for driving a supply reel and a T reel motor for driving a take-up reel, wherein the advance angle setting means sets the coil switching timing to the S reel. 2. The tape drive device according to claim 1, wherein the tape drive is performed simultaneously with respect to a motor and the T-reel motor, and the FF / REW speed can be increased and the tension when the advance angle setting is changed. It has the effect that fluctuation can be suppressed.
[0022]
According to a fourth aspect of the present invention, there is provided acceleration compensation for controlling the tape tension to be constant by using the ratio of the torque constant of the supply reel driving reel motor to the take-up reel driving reel motor during tape transfer acceleration / deceleration. 2. The tape drive device according to claim 1, which performs a torque calculation. This also enables the FF / REW speed to be increased, and suppresses a tension variation when the advance angle setting is changed. Has the effect of being able to.
[0023]
Hereinafter, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a reel motor driving means, and a three-phase brushless motor full-wave driving method, which is commonly used, will be described as an example. In FIG. 1, reference numeral 15 denotes a coil of a reel motor, 16 denotes a Hall sensor, the Hall sensor 16 detects a position of the coil 15 of the motor, and a rotor position detecting means 17 outputs a rotor magnet by an output of the Hall sensor 16. Is detected. The motor rotation information command means 18 commands the tape transfer direction to the coil energization switching means. Normally, the coil energization switching means 19 sequentially switches the current applied to the coil 15 in accordance with the rotor magnet position detected by the rotor position detection means 17 to control the motor generated torque.
[0024]
The advancing angle setting means 20 designates advancing a plurality of current timings for energizing the coil 15 with respect to the rotor magnet rotation phase. As a brushless motor drive circuit equipped with a lead angle setting means, there is, for example, a semiconductor IC: TB6537P / F manufactured by Toshiba.
[0025]
The lead angle setting means 20 operates not only to obtain the optimum torque but also to reduce the generated torque efficiency so as to reduce the efficiency, thereby obtaining a new effect as described below.
[0026]
In the brushless motor shown in FIG. 1, if the timing of switching the coil energization according to the rotor position is shifted from the timing at which the motor-generated torque is maximized, the efficiency of the force acting on the electromagnetic force generated from the coil and the magnetic force generated from the rotor is improved. And the torque generated by the motor decreases.
[0027]
FIG. 2 is a diagram for explaining the relationship between the torque constant (generally referred to as Kt) of the motor and the ST characteristic. The ST characteristic of the motor (Kt = b, b = 0.5 × a) indicated by the dotted line and the ST characteristic of the motor (Kt = a) indicated by the solid line are obtained when the same applied voltage Vm1 is used. Are shown. As is clear from FIG. 2, when the motor torque constant falls to half, the generated torque Q2 at the time of locking also falls to half of Q1. On the other hand, the number of revolutions S2 under no load can be twice as large as S1.
[0028]
As described above, the reel motor in the tape drive device is required to have two contradictory functional performances, that is, an operation of performing high-speed transfer by FF / REW or the like and an operation of performing low-speed transfer during normal recording and reproduction. The lead angle setting means 20 is supplied from a terminal 21 with the tape transfer speed information detected by the tape transfer speed detecting means (not shown). In accordance with the tape transfer speed information, the lead angle setting means 20 is operated by switching between high-speed transfer and low-speed transfer so that during high-speed transfer, the motor torque constant Kt is reduced to increase the motor rotation speed. On the contrary, at the time of low-speed transfer, the motor torque is set to the optimum efficiency by maximizing Kt.
[0029]
In general, when the motor torque constant Kt is switched, torque fluctuations are likely to occur at the time of switching. Therefore, if a plurality of types of settings are prepared and the switching is finely performed according to the tape transfer speed information, the reels may be changed. The effect can be expected to reduce the motor torque fluctuation and suppress the tape tension fluctuation. Note that the finer the setting of Kt is, the smoother the switching can be performed. Therefore, it is desirable to set the Kt to be fine enough to be regarded as stepless switching. Also, instead of having a plurality of Kt settings in advance, calculation is performed by the lead angle setting means 20 or a new calculation means is provided to perform the calculation and the result is input to the lead angle setting means 20. Kt can be set in a stepless manner.
[0030]
The tape drive has two reels, a supply reel and a take-up reel. During low-speed transfer such as recording / reproduction, the tape is driven with the capstan and pinch rollers sandwiching the tape. It is common to transfer directly between the two reels. During this high-speed transfer, the tape speed and tape tension are controlled.
At this time, the two reels do not independently constitute a control system but perform a cooperative operation. In the present invention, the lead angle setting means of both reel motor drive circuits are set to the same setting at the same time, so that the above-described cooperative control technology can be utilized. When the lead angle setting means is individually set, the ratio (KtS / KtT) of the respective torque constants (KtS: S reel motor torque constant, KtT: T reel motor torque constant) is set.
Or, KtT / KtS) is multiplied in the above-described compensation torque calculation to calculate.
[0031]
In the above description, an example has been described in which the lead angle setting means is switched in accordance with the tape transfer speed information. It can also be implemented using the tape transfer speed information obtained. Further, the present invention can be implemented by using FF / REW control operation mode information indicating whether the current operation is FF or REW, and speed information thereof.
[0032]
Further, in the present invention, a configuration in which the FF / REW tape is transferred using a reel motor has been described. However, a VTR that performs FF / REW using a capstan motor and does not use a reel motor is also known. It goes without saying that the present invention can be applied to a stun motor.
[0033]
【The invention's effect】
As described above, according to the present invention, at the time of high-speed transfer, the reel motor torque constant is set to a low characteristic, and the back electromotive voltage of the reel motor is suppressed, so that the tape transfer speed can be reduced without increasing the power supply voltage of the device. The advantageous effect that high speed can be achieved is obtained.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a main part of a tape drive device according to an embodiment of the present invention. FIG. 2 is an ST characteristic diagram of a reel motor according to an embodiment of the present invention. FIG. 3 is a configuration diagram of a conventional tape drive device. FIG. 4 is an ST characteristic diagram at the time of rewinding of the conventional tape drive. FIG. 5 is a characteristic diagram of a tape speed change at the time of rewinding of the conventional tape drive. FIG. 6 is another conventional tape drive. ST characteristic diagram at the time of rewinding
1 S reel 2 S reel rotation detection means 3 S reel speed control means 4 S reel drive means 5 S reel target rotation speed calculation means 6 S reel winding diameter detection means 8 T reel 9s, 9t S, T both reels 1, 8 Rotation speed information 10 Cylinder 11 Cylinder speed control means 12 Cylinder rotation speed detection means 13 Cylinder drive means 15 Coil 16 Hall sensor 17 Rotor position detection means 18 Motor rotation information command means 19 Coil energization switching means 20 Lead angle setting means 21 Terminal 100 Tape

Claims (4)

A tape drive device that drives a reel motor to transfer a tape,
Rotor position detecting means for detecting a rotor position of the reel motor;
Tape transfer speed detection means for detecting tape transfer speed information,
A tape drive device having lead angle setting means for setting a plurality of types of coil energization switching timing according to at least one of the rotor position and the tape transfer speed information. 2. The tape drive according to claim 1, wherein the lead angle setting means sets the coil energization switching timing using fast-forward / rewind mode information. An S reel motor for driving a supply reel,
And a T-reel motor for driving the take-up reel.
2. The tape drive device according to claim 1, wherein the advance angle setting unit sets the coil switching timing for the S reel motor and the T reel motor substantially simultaneously. 3. 2. The acceleration compensation torque calculation for controlling the tape tension to be constant using a ratio of a torque constant of a supply reel driving reel motor to a take-up reel driving reel motor during tape transfer acceleration / deceleration. Tape drive.

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