JPH07320343A - Tension controller - Google Patents

Abstract

PURPOSE:To obtain a stable tape tension without providing a tension lever. CONSTITUTION:The expected period of a frequency generator 3 is obtained from the winding diameter information of a winding diameter detector 4. An error between the actual period and expected period of the frequency generator 3 is obtained by an error calculating circuit 10. A correction torque calculating circuit 11 and a learning torque calculating circuit 12 output respective signals corresponding to the output of the error calculating circuit 10. After a pattern memory circuit 15 stores the output signal of the learning torque calculating circuit 12 temporarily, the pattern memory circuit 15 outputs the stored signal synchronously with the rotation of a reel 2. The output of the correction torque calculating circuit 11 is added to the output of the pattern memory circuit 15 by an adder 16 and the output of the adder 16 is added to a signal proportional to the winding diameter information by an adder 18 whose output is used as a torque instruction signal which drives a motor 7. With this constitution, the fluctuation of the tension of a tape-type medium can be suppressed.

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 devices using tapes, higher performance control has been required. For example, the contact state between the tape and the head. In order to keep the tape even, 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. 3 is a block diagram of a conventional tension control device.
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. 4 is a signal waveform diagram of each part of the conventional tension control device. Q is an output signal of the frequency generator 3, r is an output signal of the back torque calculating circuit 5, and T0 is generated by the motor 7. It is torque.

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 q 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 r 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-mentioned structure, the tension of the tape fluctuates due to the torque fluctuation peculiar to the motor and the tape transfer speed fluctuates due to the expansion and contraction of the tape, no matter how accurately the winding diameter is detected. In addition, since the contact between the head and the tape becomes unstable, there is a problem that it is necessary to use an expensive motor with less torque fluctuation peculiar to the motor or to sacrifice the recording / reproducing performance.

In view of the above problems, it is an object of the present invention to provide a tension control device for performing stable tension control with less tape tension fluctuation even if there is torque fluctuation peculiar to the motor. .

[0010]

In order to achieve the above object, a tension control device of the present invention comprises a reel around which a tape-shaped medium is wound, and a tape transfer for pulling the tape-shaped medium out of the reel and running it at a constant speed. Means, a motor for driving the reel, a driving means for causing the motor to generate a torque corresponding to an input signal, a rotation state detecting means for detecting a rotation speed of the motor or a time for rotating the motor by a unit angle, and the reel. A winding diameter detecting means for detecting the winding diameter of the tape-shaped medium included therein, and an expected value output means for outputting an expected value of the output signal of the rotation state detecting means corresponding to the output of the winding diameter detecting means and the set transfer speed. And an error calculating means for outputting an error between the output signal of the rotation state detecting means and the output signal of the expected value outputting means, and based on the output signal of the error calculating means A correction torque calculating means for outputting a first torque signal, and the learning torque calculating means for outputting the second torque signal based on the output signal of said error calculating means,
A rotation position detector that detects the rotation position of the motor, and stores the output of the learning torque calculation means in synchronization with the output of the rotation position detector for a period of one rotation or more of the motor,
Thereafter, storage means for outputting the stored signal in synchronization with the output of the rotational position detector, addition means for adding the output signal of the correction torque calculation means and the output signal of the storage means, and the output signal of the addition means Switching means for outputting or shutting off, a torque setting means for outputting a predetermined torque signal in a direction for suppressing the feeding of the tape-shaped medium, an output signal of the torque setting means and an output signal of the switching means are combined. , Synthesizing means for transmitting to the driving means.

[0011]

According to the present invention, the tape-shaped medium wound on the reel is transferred at a constant speed by the tape transfer means. The rotation state detecting means detects a plurality of rotation speeds or rotation times of a unit angle per one rotation of the motor. The winding diameter detecting means obtains winding diameter information of the tape-shaped medium wound on the reel. The expected value output means outputs the expected value of the output signal of the rotation state detecting means from the winding diameter information of the winding diameter detecting means and the tape transfer speed. The error calculation means detects an error between the output signal of the rotation state detection means and the output signal of the expected value output means, thereby detecting a torque fluctuation or the like peculiar to the motor as a fluctuation in the rotation state. The correction torque calculating means and the learning torque calculating means output torque signals having respective characteristics based on the output signal of the error calculating means. The storage means first stores the output of the learning torque calculation means in synchronization with the output of the rotational position detector for a period of one rotation or more of the motor. Then, the stored torque signal is reproduced and output in synchronization with the output of the rotational position detector.
The torque setting means outputs a predetermined torque signal. The adder circuit outputs a torque signal obtained by adding the output signal of the storage means and the output signal of the correction torque calculation means. The synthesis circuit is
The output of the adder circuit obtained through the output of the connecting means and the output of the torque setting means are combined and transmitted to the drive means. The drive means generates torque in the motor corresponding to the output of the combining means, and applies tension to the tape-shaped medium. That is, since the torque fluctuations peculiar to the motor are canceled by the torque signal of the correction torque calculating means and the torque signal of the memory circuit, the fluctuation of tension applied to the tape-shaped medium is suppressed, and only the torque signal of the torque setting means and the winding diameter of the tape-shaped medium are suppressed. The tension determined by can be obtained.

[0012]

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

FIG. 1 is a block diagram showing the configuration of a tension control device according to an embodiment of the present invention. In FIG. 1, the same parts as those of the conventional tension control device shown in FIG. 3 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 110.
And a winding command terminal 111, which is a tape transfer means for transferring the tape 101 at a constant speed, and 8 is a frequency generator 3.
Of the winding diameter detection circuit 4 and a cycle detection circuit 8 corresponding to the set transfer speed.
Period calculation circuit that outputs the expected value of the output signal of
Is an error calculation circuit that outputs an error between the output signal of the cycle detection circuit 8 and the output signal of the expected cycle calculation circuit 9, 11 is a correction torque calculation circuit that outputs a torque signal proportional to the output signal of the error calculation circuit 10, and 12 Is a learning torque calculation circuit that detects a predetermined frequency component of the output signal of the error calculation circuit 10 and outputs a torque signal that has been phase-corrected, and 13 outputs a pulse signal once per rotation that serves as the rotational position reference of the motor 7. A rotational position detector 14 for externally giving a low level (hereinafter abbreviated as L level) signal corresponding to a memory command or a high level (hereinafter abbreviated as H level) signal corresponding to a reproduction command. A storage / reproduction command terminal, 15 is a pattern for storing and reproducing the output signal of the learning torque calculation circuit 12 in synchronization with the output of the rotational position detector 13 in accordance with the output of the storage / reproduction command terminal 14. A memory circuit, 16 is an adder circuit for adding the output signal of the correction torque calculation circuit 11 and the output signal of the pattern memory circuit 15, 17 is a switch connected to the output of the adder circuit 16 and operated by the memory reproduction command terminal 14, Reference numeral 18 denotes an adder circuit for adding the output signal of the switch 17 and the output signal of the back torque calculation circuit 5 and transmitting the result to the drive means 6.

FIG. 2 is a signal waveform diagram of each part in this embodiment. In FIG. 2, a is an output signal of the expected cycle calculation circuit 9, b is an output signal of the cycle detection circuit 8, c is an output signal of the correction torque calculation circuit 11, and d is a learning torque calculation circuit 12.
Output signal of the position detector 13, f is a signal of the memory reproduction command terminal 14 input from the outside, g is an output signal of the pattern storage circuit 15, h is an output signal of the addition circuit 16, and i is This is the output signal of the adder circuit 18.

The operation of the tension control device of this embodiment 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, the drive circuit 110 applies the winding torque to the motor 109 in accordance with the signal applied to the winding command terminal 111.
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 having a frequency proportional to the rotation speed of the reel 2, the tape 10
When the transport speed of 1 is substantially constant, the winding diameter detection circuit 4 detects the time required for one rotation of the motor 7 from the output signal of the frequency generator 3 to wind the tape 101 wound on the reel 2.
Get the winding diameter information. The back torque calculation circuit 5 outputs a torque signal having a value B proportional to the output of the winding diameter detection circuit 4.
The cycle detection circuit 8 outputs a signal b proportional to the signal cycle of the frequency generator 3. The expected cycle calculation circuit 9 outputs the output signal a of the expected value A of the output signal of the cycle detection circuit 8 which is determined by the winding diameter of the tape 101 wound around the reel 2 and the transfer speed. The error calculation circuit 10 outputs a signal obtained by subtracting the value of the signal b from the value of the signal a. Correction torque calculation circuit 11
Outputs a value proportional to the output signal of the error calculation circuit 10 as the correction torque signal c. The learning torque calculation circuit 12 detects only a predetermined frequency component of the output signal of the error calculation circuit 10 and outputs the torque signal d with the phase corrected.

Here, the operation of the storage / playback command terminal 14 for each state of the signal f will be described. The operation when the signal f at the memory / reproduction command terminal 14 is at the L level will be described. The pattern storage circuit 15 synchronizes with the pulse of the output signal e of the rotation position detector 13, and the learning torque calculation circuit 12 for one rotation of the motor 7.
The output signal d of is sequentially stored. The adder circuit 16 outputs a torque signal h obtained by adding the output signal c of the correction torque calculation circuit 11 and the output signal g of the pattern storage circuit 15. However, since the switch 17 blocks the transmission of the signal h, the adder circuit 18 outputs the signal i which is the output value B of the back torque calculation circuit 5 as it is. The drive circuit 6 causes the motor 7 to generate a torque proportional to the output signal i of the adder circuit 18,
Apply tension to 01. At this time, the rotation speed of the motor 7 fluctuates due to inherent torque fluctuations that the motor 7 has, but a signal d corresponding to this fluctuation is stored in the pattern storage circuit 15.

Next, the operation when the signal f at the memory / reproduction command terminal 14 is at the H level will be described. Pattern memory circuit 1
Reference numeral 5 sequentially reproduces and outputs the memory signal i for one rotation of the motor 7 in synchronization with the pulse of the output signal e of the rotational position detector 13. The adder circuit 16 outputs a torque signal h obtained by adding the output signal c of the correction torque calculation circuit 11 and the output signal g of the pattern storage circuit 15. Since the switch 17 transmits the transmission of the signal h to the addition circuit 18, the addition circuit 18 outputs the signal i obtained by adding the output signal of the back torque calculation circuit 5 and the signal h. The drive circuit 6 outputs the output signal i of the adder circuit 18.
Is generated in the motor 7 and the tape 101
Give tension to. At this time, the inherent torque fluctuation potentially possessed by the motor 7 is reduced, and the total torque appearing in the motor 7 is stabilized. That is, it is possible to suppress the fluctuation in tension applied to the tape 101.

As described above, in this embodiment, torque fluctuations peculiar to the motor 7 and the like are detected as speed fluctuations of the motor 7, one rotation of the motor 7 is temporarily stored, and then the motor 7 is stored based on the stored value. It is possible to always provide a stable tension by correcting the torque generated by and feeding back the signal corresponding to the residual speed fluctuation.

The correction torque calculation circuit 11 in the embodiment includes a low-pass filter or a band-pass filter at the time of input or output so that the same effect can be obtained even if the torque fluctuation limited to the band is canceled. It doesn't stop there.

Further, in the embodiment, the reel 2 is the motor 7
In the case where the frequency generator 3 and the rotational position detector 13 detect the rotational state of the reel 2 in the case of being directly connected to the rotating shaft of No. 1, the same effect can be obtained, and the present invention is not limited to the embodiment. .

Further, in the embodiment, the winding diameter detecting circuit 4,
Back torque calculation circuit 5, cycle detection circuit 8, expected cycle calculation circuit 9, error calculation circuit 10, correction torque calculation circuit 1
1, a learning torque calculation circuit 12, a pattern storage circuit 15,
The addition circuits 16 and 18 and the speed control circuit 106 can be realized by software processing by a computer system capable of time management, and are not limited to the embodiments.

In the embodiment, as a method for winding the tape 101 on the reel 108, the dedicated motor 1 is used.
09 and the drive circuit 110 thereof have been described, the method of driving the reel 108 by mechanically distributing the driving force of the capstan motor 105 may be considered, and the present invention is not limited to the embodiment.

Further, in the embodiment, the pattern storage circuit 15 stores and reproduces the variation pattern for one rotation of the motor 7 in synchronization with the position detector 13, but not only the rotation position detector 13 Even if the fluctuation pattern for one rotation of the motor 7 is stored and reproduced in synchronization with the output signal of the frequency generator 3, the same effect can be obtained, and the present invention is not limited to the embodiment.

Further, in the embodiment, the winding diameter detection circuit 4 is configured to detect using the signal of the frequency generator 3, but mechanical detection, optical detection, etc. are conceivable, and it is not limited to the embodiment. Absent.

In the embodiment, the error signal of the error calculation circuit 10 is obtained as the period error of the frequency generator 3. However, the error signal of the frequency generator 3 may be obtained as the frequency error of the frequency generator 3, and the present invention is limited to the embodiment. is not.

[0028]

As described above, the present invention is provided with the rotation state detecting means, the winding diameter detecting means, the expected value outputting means, the error calculating means, the correction torque calculating means, the learning torque calculating means, the storing means and the adding means. By this, even if there is a torque fluctuation peculiar to the motor or a tape speed fluctuation due to a resonance operation generated between the tape and the reel, it works to cancel the fluctuation. Can be given. Furthermore, it is not necessary to use a motor with uniform torque fluctuation. When the recording / reproducing head is installed, the contact state between the tape-shaped medium and the recording / reproducing head is kept stable. Also, because it is possible to give a stable tension, it is not necessary to install a tension detection sensor,
The size and weight of the device can be reduced. Further, the two methods of reducing fluctuations used in the present invention are a combination with less interference, and realize rationalization in which the constituent elements are shared.

[Brief description of drawings]

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

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

FIG. 3 is a block diagram showing the configuration of a conventional tension control device.

FIG. 4 is a signal waveform diagram of each part in a conventional tension control device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 tape transfer means 2 reel 4 winding diameter detection circuit (rolling diameter detection means) 5 back torque calculation circuit (torque setting means) 6 drive circuit (driving means) 7 motor 8 cycle detection circuit (rotation state detection means) 9 expected Cycle calculation circuit (expected value output means) 10 Error calculation circuit (error calculation means) 11 Correction torque calculation circuit (correction torque calculation means) 12 Learning torque calculation circuit (learning torque calculation means) 13 Rotation position detector 15 Pattern storage circuit ( Storage means 16 Addition circuit (addition means) 17 Switch (switching means) 18 Addition circuit (synthesis means) 101 Tape-shaped medium

Claims (1)

[Claims] 1. A reel around which a tape-shaped medium is wound, a tape transfer means for pulling the tape-shaped medium out of the reel and traveling at a constant speed, a motor for driving the reel, and a torque corresponding to an input signal. A drive means for causing the motor to generate, a rotation state detection means for detecting a rotation speed of the motor or a time for rotating the motor by a unit angle, a winding diameter detection means for detecting a winding diameter of the tape-shaped medium including the reel, Expected value output means for outputting an expected value of the output signal of the rotation state detection means corresponding to the output of the winding diameter detection means and the set transfer speed, an output signal of the rotation state detection means and an output signal of the expected value output means An error calculating means for outputting an error between the error calculating means, a correction torque calculating means for outputting a first torque signal based on an output signal of the error calculating means, and the error calculating means. Learning torque calculating means for outputting a second torque signal based on the output signal of the stage, a rotational position detector for detecting the rotational position of the motor, and a rotational position detector for one or more revolutions of the motor. A storage unit that stores the output of the learning torque calculation unit in synchronization with the output and then outputs the stored signal in synchronization with the output of the rotational position detector; an output signal of the correction torque calculation unit and the storage unit. Adding means for adding the output signals of the above, a switching means for outputting or blocking the output signal of the adding means, a torque setting means for outputting a predetermined torque signal in a direction for suppressing the delivery of the tape-shaped medium, and the torque And a synthesizing means for synthesizing the output signal of the setting means and the output signal of the switching means and transmitting the synthesized signal to the driving means, and the tension for keeping the tension of the tape-shaped medium constant. ® emission control device.