JPH06208746A - Tension controller - Google Patents

Abstract

PURPOSE:To attain stabilized tape tension without requiring any tension lever. CONSTITUTION:A tape medium 101 is fed by a tape feed means 1 at a constant rate. A winding diameter detecting circuit 40 obtains winding diameter information of the tape medium 101 wound around a reel 2. A back torque operating circuit 5 outputs a signal proportional to the output from the winding diameter detecting circuit 4. A torque pattern generating circuit 9 outputs a predetermined variation pattern signal in synchronism with the output from a pulse generator 8. An adder 10 synthesizes signals from the back torque operating circuit 5 and the torque pattern generating circuit 9. A drive circuit 6 drives a motor 7 to generate torque based on an output from the adder 10 and imparts tension to the tape medium 10. In this regard, variation pattern of the torque pattern generating circuit 9 is set to offset variation of torque inherent to the motor 7 thus restraining variation in the tension of the tape medium 101.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape tension control device in a tape running system such as a video tape recorder and an audio tape recorder.

[0002]

2. Description of the Related Art In recent years, with the progress of thinner and thinner tapes in recording / reproducing apparatuses using tapes, higher performance control is required. For example, contact between the tape and the head is required. In order to keep it uniform, tape tension control is essential. On the other hand, since there is a strong demand for downsizing and weight reduction of the device, there has been proposed a tension control device (for example, Japanese Patent Laid-Open No. 1-271953) in which a tape tension detection sensor is not installed and the mechanism is simplified.

A conventional tension control device will be described below with reference to the drawings. FIG. 5 is a block diagram of a conventional tension control device, 2 and 108 are reels and 3
Is a frequency generator, 4 is a winding diameter detection circuit, 5 is a back torque calculation circuit, 6 and 110 are drive circuits, 7 and 109 are motors, 101 is tape, 102 and 103 are posts, and 104 is
Is a recording / reproducing head, 105 is a capstan motor, 10
6 is a speed control circuit, 107 is a pinch roller, and 111 is a winding command terminal.

FIG. 6 is a signal waveform diagram of each part of the conventional tension control device, where m is the output signal of the frequency generator 3 and n is the output signal of the back torque calculation circuit 5 (or the winding diameter detection circuit 4). , T0 are torques generated by the motor 7.

The operation of the tension control device constructed as above will be described below.

The tape 101 is a capstan motor 105.
It is conveyed at a constant speed by the speed control circuit 106 in a state of being sandwiched between the shaft and the pinch roller 107. At this time,
In response to the signal applied to the winding command terminal 111, the drive circuit 110 applies the winding torque to the motor 109 and the reel 10
Since the tape 8 is rotated, the tape 101 is wound on the reel 108. Further, the tape 101 is supplied from the reel 2.

On the other hand, since the frequency generator 3 outputs a signal m having a frequency proportional to the rotation speed of the reel 2, the tape 1
When the transfer speed of 01 is constant, the winding diameter detection circuit 4 detects the cycle of the output signal of the frequency generator 3 to obtain the winding diameter information of the tape 101 wound on the reel 2. The back torque calculation circuit 5 outputs a torque signal n proportional to the output of the winding diameter detection circuit 4, and the drive circuit 6 generates a torque to the motor 7 in the direction in which the feeding of the tape 101 is suppressed in accordance with the torque signal. Therefore, the tape is supplied while applying tension to the tape 101. That is, since the torque T0 proportional to the winding diameter of the tape 101 wound on the reel 2 is applied, the tension of the tape 101 at the supply end becomes almost constant, and the contact state of the recording / reproducing head 104 is kept substantially stable. .

[0008]

However, in the above structure, the tension of the tape fluctuates due to the torque fluctuation peculiar to the motor, no matter how accurately the winding diameter is detected,
As the tape transfer speed fluctuates or the contact between the head and tape becomes unstable, use an expensive motor or
There was a problem that the recording and reproducing performance had to be sacrificed.

In view of the above problems, the first object of the present invention is to stabilize the tape tension fluctuation with a simple structure when the torque fluctuation pattern is known even if there is a torque fluctuation peculiar to the motor. It is an object of the present invention to provide a tension control device that performs the above tension control.

A second object of the present invention is to provide a tension control device for performing stable tension control without fluctuations in tape tension even if there are fluctuations in the torque fluctuations of the motor mounted during manufacturing. .

[0011]

In order to achieve the above first object as a first structure, a tension control device of the present invention comprises a reel around which a tape-shaped medium is wound, and the tape-shaped medium from the reel. A tape transfer means for running the tape at a constant speed for drawing out, a motor for giving a torque to the reel in a direction for suppressing the feeding of the tape-shaped medium, a driving means for generating a torque corresponding to an input signal in the motor, A rotation position detector that detects the rotation position of the motor, a winding diameter detection unit that outputs a signal corresponding to the radius or diameter of the tape-shaped medium wound around the reel, and a proportional to the output signal of the winding diameter detection unit And a torque pattern generation circuit that outputs a torque signal having a predetermined fluctuation pattern in synchronization with the output of the rotational position detector. If, and an adding circuit for transmitting the combined signal with the output of the output and the torque pattern generation circuit of the back torque computing circuit to said driving means.

In order to achieve the above-mentioned second object as a second structure, the tension control device of the present invention comprises a reel around which a tape-shaped medium is wound, and the tape-shaped medium is pulled out from the reel at a constant speed. A tape transfer means for running, a motor for giving a torque to the reel in a direction for suppressing the feeding of the tape-like medium, a driving means for generating a torque corresponding to an input signal in the motor, and a rotation speed of the motor. Alternatively, a rotation state detector that detects a state corresponding to a rotation cycle, a rotation position detector that detects a rotation position of the motor, and a radius of the tape-shaped medium wound on the reel from an output of the rotation state detector. Alternatively, a winding diameter detection circuit that outputs a signal corresponding to the diameter, and a back torque calculation circuit that outputs a torque signal proportional to the output signal of the winding diameter detection circuit, A speed error detection circuit for outputting an error signal with respect to the target rotational speed or a target rotation period from the output of the serial rotation state detector, a speed control circuit which outputs a torque signal to a substantially constant rotational speed of the motor,
A pattern storage circuit for storing a variation pattern of the output signal of the speed error detection circuit for one rotation of the motor in synchronization with the output signal of the rotational position detector when the operation command signal from the outside is a speed control command; When the operation command signal is a tension control command, one of the motors stored in the pattern storage circuit is synchronized with the output signal of the rotational position detector.
A torque pattern generation circuit that outputs a torque signal according to a variation pattern of rotations, an addition circuit that outputs a combined signal of the output of the back torque calculation circuit and the output of the torque pattern generation circuit, and the operation command signal A switching circuit for transmitting the output of the speed control circuit to the drive means when the speed control command is given, and for transmitting the output of the addition circuit to the drive means when the operation command signal is the tension control command. .

[0013]

According to the first aspect of the present invention, the tape-shaped medium is transferred at a constant speed by the tape transfer means, and the winding diameter detection circuit obtains the winding diameter information of the tape-shaped medium wound on the reel. The back torque calculation circuit outputs a torque signal proportional to the output of the winding diameter detection circuit, and the torque pattern generation circuit outputs a torque signal of a predetermined fluctuation pattern synchronized with the output of the rotational position detector. The adder circuit outputs a torque signal that combines the output of the back torque calculation circuit and the output of the torque pattern generation circuit. The drive means causes the motor to generate a torque corresponding to the output of the adder circuit and applies a tension to the tape-shaped medium. At this time, the fluctuation of the tension applied to the tape-shaped medium can be suppressed by setting the fluctuation pattern of the torque pattern generation circuit so as to cancel the torque fluctuation unique to the motor.

According to the second structure of the present invention, first, when a speed control command is given as an operation command signal from the outside before mounting the tape-shaped medium to the tension control device of the present invention, the speed error detection circuit causes the motor to operate. It outputs a torque signal to keep the rotation speed constant. Since the switching circuit transmits the output of the speed control circuit to the drive means, the motor rotates at a predetermined rotation speed. At this time, if there is a torque fluctuation peculiar to the motor, a disturbance is applied to the speed control system of the motor, resulting in a minute rotation speed fluctuation. The pattern storage circuit stores a pattern of rotation speed fluctuation (output of the speed error detection circuit) for one rotation of the motor in synchronization with the output signal of the rotation position detector. Next, when the tape-shaped medium is attached and a tension control command is given as an operation command signal from the outside, the tape-shaped medium is transferred at a constant speed by the tape transfer means. Since the rotation state detector detects the rotation speed (or rotation cycle) of the motor, when the tape-shaped medium transfer speed is constant,
The winding diameter detection circuit obtains winding diameter information of the tape-shaped medium wound on the reel from the output of the rotation state detector. The back torque calculation circuit outputs a torque signal proportional to the output of the winding diameter detection circuit, and the torque pattern generation circuit outputs a torque signal according to the variation pattern of one rotation of the motor stored in the pattern storage circuit to the rotation position detector. Output in synchronization with the output of.
The adder circuit outputs a torque signal that combines the output of the back torque calculation circuit and the output of the torque pattern generation circuit.
Since the switching circuit transmits the output of the adding circuit to the driving means,
The drive means causes the motor to generate a torque corresponding to the output of the adder circuit and applies a tension to the tape-shaped medium. At this time, the output of the torque pattern generating circuit acts to cancel the torque fluctuations peculiar to the motor, and thus the fluctuations in tension applied to the tape-shaped medium can be suppressed.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the structure of a tension control device according to the first embodiment of the present invention. In FIG. 1, the same parts as those of the conventional tension control device shown in FIG. 5 are designated by the same reference numerals and the description thereof will be omitted. 1 is a capstan motor 105, a speed control circuit 106, a pinch roller 107, a reel 108, a motor 109, and a drive circuit 1
10 and a winding command terminal 111, and the tape 101
Means for transferring the tape at a constant speed, 30 is a motor 7
, A frequency generator that outputs a signal of a frequency proportional to the rotation speed of the motor, 40 is a winding diameter detecting means composed of the frequency generator 30 and the winding diameter detection circuit 4, and 8 is a pulse generated once for one rotation of the motor 7. A pulse generator for detecting the rotational position, a torque pattern generating circuit 9 for outputting a torque signal having a predetermined fluctuation pattern in synchronization with the output of the pulse generator 8, and 10 an output of the back torque calculating circuit 5 and a torque pattern generating circuit. 9 is an adder circuit for synthesizing and outputting 9 outputs.

FIG. 2 is a signal waveform diagram of each part in the first embodiment. In FIG. 2, a is an output signal of the frequency generator 30, b is an output signal of the back torque calculation circuit 5 (or the winding diameter detection circuit 4), and c is an output signal of the pulse generator 8.
d is the output signal of the torque pattern generating circuit 9, e is the output signal of the adding circuit 10, and T1 is the torque generated by the motor 7.

The operation of the tension control device of the first embodiment constructed as described above will be described below.

The tape 101 is a capstan motor 105.
It is conveyed at a constant speed by the speed control circuit 106 in a state of being sandwiched between the shaft and the pinch roller 107. At this time,
In response to the signal applied to the winding command terminal 111, the drive circuit 110 applies the winding torque to the motor 109 and the reel 10
Since the tape 8 is rotated, the tape 101 is wound on the reel 108. Further, the tape 101 is supplied from the reel 2.

On the other hand, since the frequency generator 30 outputs a signal a having a frequency proportional to the rotation speed of the reel 2, the winding diameter detection circuit 4 outputs the output signal of the frequency generator 30 when the transfer speed of the tape 101 is constant. The winding diameter information of the tape 101 wound around the reel 2 is obtained by detecting the cycle of a. The back torque calculation circuit 5 outputs a torque signal b proportional to the output of the winding diameter detection circuit 4. Further, the torque pattern generation circuit 9 outputs a torque signal d having a predetermined fluctuation pattern for one rotation of the motor 7 in synchronization with the output signal c of the pulse generator 8. The adder circuit 10 outputs a torque signal e that is a combination of the torque signal b and the torque signal d. The drive circuit 6 drives the motor 7 in response to the torque signal e to apply tension to the tape 101. At this time, the fluctuation pattern of the torque pattern generation circuit 9 is set so as to cancel the torque fluctuation peculiar to the motor 7, so that the torque T1 generated by the motor 7 becomes constant and the fluctuation in tension applied to the tape 101 is suppressed. You can

As described above, in the first embodiment,
Even if there is a torque fluctuation specific to the motor 7, a stable tension can always be applied, and the contact state of the recording / reproducing head 104 can be kept stable.

Next, a second embodiment of the present invention will be described with reference to the drawings. FIG. 3 is a block diagram showing the configuration of the tension control device in the second embodiment.
In FIG. 3, the same parts as those in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted. 11 is an operation command terminal that gives a speed control command or a tension control command, 12 is a speed error detection circuit that outputs an error signal between the frequency (or cycle) of the output signal of the frequency generator 30 and the target frequency (or target cycle), Thirteen
Is a speed control circuit that outputs a torque signal for driving the motor 7 so that the output of the speed error detection circuit 12 approaches zero, and 14 is a pulse generator 8 when a speed control command is given to the operation command terminal 11. Motor 7 in synchronization with the output signal of
1 is a pattern storage circuit that stores the variation pattern of the output signal of the speed error detection circuit 12 for one rotation. Reference numeral 17 is one of the motors 7 stored in the pattern storage circuit 14 when a tension control command is given to the operation command terminal 11. A pattern storage circuit that outputs a torque signal corresponding to the fluctuation pattern of the rotation amount in synchronization with the output signal of the pulse generator 8, and 15 is a composite signal of the output of the back torque calculation circuit 5 and the output of the torque pattern generation circuit 17. An adder circuit 16 outputs a speed control circuit 1 when a speed control command is given to the operation command terminal 11.
3 is a switch for transmitting the output of the adder circuit 15 to the drive circuit 6 when the output of the adder circuit 15 is transmitted to the drive circuit 6 and a tension control command is given to the operation command terminal 11.

FIG. 4 is a signal waveform diagram of each part in the second embodiment. In FIG. 4, f is the output signal of the frequency generator 30, g is the output signal of the pulse generator 8, h is the output signal of the speed error detection circuit 12, i is the output signal of the torque pattern generation circuit 17, and j is the back torque. The output signal of the arithmetic circuit 5, k is the output signal of the addition circuit 15, and T2 is the torque generated by the motor 7.

The operation of the tension control device of the second embodiment constructed as above will be described below.

First, before attaching the tape 101 to the tension control device of the second embodiment or pressing the tape 101 with the capstan motor 105 and the pinch roller 107, a speed control command is given to the operation command terminal 11. The speed error detection circuit 12 outputs an error signal h between the rotation speed (or rotation cycle) of the motor 7 and a predetermined target rotation speed (or target rotation cycle) according to the output signal f of the frequency generator 30, and the speed control circuit 13 is a speed error detection circuit 12
The torque signal is output so that the error output of is eliminated. The switch 16 transmits the output of the speed control circuit 13 to the drive circuit 6, so that the motor 7 rotates at a predetermined rotation speed. At this time, if there is a torque fluctuation specific to the motor 7,
As a result, disturbance is added to the speed control system, and minute rotation speed fluctuations occur. The pattern storage circuit 14 includes a pulse generator 8
The rotation speed fluctuation (output signal h of the speed error detection circuit 12) pattern for one rotation of the motor 7 is stored in synchronization with the output signal g. Next, the tape 101 is attached, and the tape 101 is attached by the capstan motor 105 and the pinch roller 107.
When the tape 101 is pressed and a tension control command is given to the operation command terminal 11, the tape 101 is transferred by the tape transfer means 1 at a constant speed. Since the frequency generator 30 detects the rotation speed (or rotation cycle) of the motor 7, when the tape 101 transfer speed is constant, the winding diameter detection circuit 4 causes the frequency generator 3 to rotate.
Tape 10 wound on reel 2 from output signal f of 0
1. Obtain the winding diameter information of 1. The back torque calculation circuit 5 outputs a torque signal proportional to the output of the winding diameter detection circuit 4, and the torque pattern generation circuit 17 synchronizes with the output of the pulse generator 8 and outputs 1 of the motor 7 stored in the pattern storage circuit 14. The torque signal i corresponding to the variation pattern of the rotation is output. The adder circuit 15 outputs a torque signal k that combines the output of the back torque calculation circuit 5 and the output of the torque pattern generation circuit 17. The switch 16 transmits the output of the adder circuit 15 to the drive circuit 6, so that the drive circuit 6 drives the motor 7 in response to the torque signal k and applies tension to the tape 101.
At this time, the output of the torque pattern generation circuit 17 acts so as to cancel the torque fluctuation unique to the motor 7, so that the torque T2 generated by the motor 7 becomes constant, and the fluctuation in tension applied to the tape 101 can be suppressed.

As described above, in the second embodiment,
The motor 7 to be installed has its own torque fluctuation.
Even if the torque fluctuation state varies, the torque fluctuation state of the motor 7 is learned before performing the tension control, so that a stable tension can always be applied and the contact state of the recording / reproducing head 104 can be kept stable. Be done. Further, it is not necessary to manufacture the motor 7 with uniform torque fluctuation.

The pattern storage circuit 14 or the torque pattern generation circuit 17 in each of the above-described embodiments includes a low-pass filter or a band-pass filter at the time of input or output to cancel torque fluctuation in a limited band.
It is obvious that the signal accuracy of the frequency generator 30 can be prevented from affecting, and the invention is not limited to the embodiment.

When the reel 2 is directly connected to the rotating shaft of the motor 7 in each of the above-described embodiments, the frequency generator 30 and the pulse generator 8 are configured to detect the rotating state of the reel 2. Similar effects are obtained, and the present invention is not limited to the embodiments.

In each of the above embodiments, the winding diameter detecting circuit 4, the back torque calculating circuit 5, the torque pattern generating circuits 9 and 17, the adding circuits 10 and 15, the speed error detecting circuit 1
2. The speed control circuit 13, the pattern storage circuit 14, and the switch 16 can be realized by software processing by a computer system capable of time management, and are not limited to the embodiments.

In each of the above embodiments, the reel 10
As an example of the method for winding the tape 101 around the tape 8, the dedicated motor 109 and its drive circuit 110 have been shown, but the reel 108 is driven by mechanically distributing the driving force of the capstan motor 105. Methods and the like are conceivable and are not limited to the examples.

In each of the above embodiments, the torque pattern generation circuits 9 and 17 and the pattern storage circuit 14 output the torque signal of the fluctuation pattern for one rotation of the motor 7 in synchronization with the pulse generator 8. Although shown, the same effect can be obtained by outputting the torque signal of the fluctuation pattern for one rotation of the motor 7 in synchronization with the output signal of the frequency generator 30 as well as the pulse generator 8. It doesn't stop there.

In the first embodiment, the winding diameter detecting means 40 is composed of the frequency generator 30 and the winding diameter detecting circuit 4, but mechanical detection and optical detection are considered. However, it is not limited to the embodiment.

In the second embodiment, the speed control circuit 13 keeps the output of the speed error detection circuit 12 constant, but the speed control circuit 13 may output a fixed torque signal.
The same effect can be obtained because the speed becomes constant at least below the no-load rotation speed of the motor, and the present invention is not limited to the embodiment.

[0034]

As described above, according to the present invention, even if there is a torque fluctuation peculiar to the motor, it works to cancel the torque fluctuation. Therefore, the fluctuation of the tension applied to the tape-shaped medium is suppressed and the stable tension is always applied. be able to. That is, when the recording / reproducing head is installed, the contact state between the tape-shaped medium and the recording / reproducing head can be kept stable. Further, since a stable tension can be applied, it is not necessary to install a tension detection sensor, and the device can be made smaller and lighter.

[Brief description of drawings]

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

FIG. 2 is a signal waveform diagram of each part in the first embodiment.

FIG. 3 is a block diagram showing a configuration of a tension control device according to a second embodiment of the present invention.

FIG. 4 is a signal waveform diagram of each part in the second embodiment.

FIG. 5 is a block diagram showing a configuration of a conventional tension control device.

FIG. 6 is a signal waveform diagram of each part in a conventional tension control device.

[Explanation of symbols]

 1 Tape Transfer Means 2 Reel 4 Roll Diameter Detection Circuit 5 Back Torque Calculation Circuit 6 Driving Means 7 Motor 8 Rotation Position Detector 9,17 Torque Pattern Generation Circuit 10,15 Addition Circuit 12 Speed Error Detection Circuit 13 Speed Control Circuit 14 Pattern Storage Circuit 16 Switching circuit 30 Rotation state detector 40 Roll diameter detection means 101 Tape-shaped medium

Claims (2)

[Claims] 1. A reel around which a tape-shaped medium is wound, a tape transfer means for pulling out the tape-shaped medium from the reel and traveling at a constant speed, and a torque in a direction for suppressing the delivery of the tape-shaped medium to the reel. A motor for giving, a driving means for generating a torque corresponding to an input signal in the motor, a rotational position detector for detecting a rotational position of the motor, a radius or a diameter of the tape-shaped medium wound on the reel. Winding diameter detection means for outputting a signal corresponding to, a back torque calculation circuit for outputting a torque signal proportional to the output signal of the winding diameter detection means, and a predetermined fluctuation pattern in synchronization with the output of the rotational position detector. A torque pattern generating circuit for outputting a torque signal of the above, and a combined signal of the output of the back torque calculating circuit and the output of the torque pattern generating circuit. Comprising a summing circuit for transmitting the driving means, the tension control device to keep the tension of the tape-like medium to be delivered constant. 2. A reel around which a tape-shaped medium is wound, a tape transfer means for pulling out the tape-shaped medium from the reel and traveling at a constant speed, and a torque in a direction for suppressing the delivery of the tape-shaped medium to the reel. A motor for giving, a drive means for generating a torque corresponding to an input signal in the motor, a rotation state detector for detecting a state corresponding to a rotation speed or a rotation cycle of the motor, and a rotation position of the motor A rotation position detector, a winding diameter detection circuit that outputs a signal corresponding to the radius or diameter of the tape-shaped medium wound on the reel from the output of the rotation state detector, and an output signal of the winding diameter detection circuit And a back torque calculation circuit that outputs a torque signal proportional to the error signal for the target rotation speed or the target rotation cycle from the output of the rotation state detector. Output speed error detection circuit, a speed control circuit that outputs a torque signal for making the rotation speed of the motor almost constant, and an output of the rotational position detector when an operation command signal from the outside is a speed control command A pattern storage circuit that stores a variation pattern of the output signal of the speed error detection circuit for one rotation of the motor in synchronization with the signal; and an output signal of the rotational position detector when the operation command signal is a tension control command. And a torque pattern generation circuit that outputs a torque signal according to a variation pattern of one rotation of the motor stored in the pattern storage circuit, an output of the back torque calculation circuit and an output of the torque pattern generation circuit. An adder circuit for outputting a combined signal of, and an output of the speed control circuit is transmitted to the drive means when the operation command signal is a speed control command, A tension control device comprising a switching circuit for transmitting the output of the adding circuit to the driving means when the operation command signal is a tension control command, and keeping the tension of the tape-shaped medium to be sent constant.