JP2787109B2 - Reel replaceable magnetic tape device and method - Google Patents

Description

The present invention relates to a reel-replaceable magnetic tape apparatus and method for transferring a magnetic tape from one reel to another at a constant speed while applying a constant tension to the magnetic tape. About.

[Conventional technology]

The magnetic tape device includes a reel exchange type in which the reel can be exchanged and a fixed reel type in which the reel cannot be exchanged. Here, the reel exchange type is used.

A conventional reel-replaceable magnetic tape device is disclosed in
As described in -74448, when attaching the replacement reel to the magnetic tape device, the free end of the tape on the replacement reel is fixed, and the replacement reel is rotated in the tightening direction, and any of the replacement reel is rotated. If rotation is sensed, the tape is rewound, otherwise the inter-layer slip on the replacement reel is checked, comprising the step of indicating that the replacement reel is available.

[Problems to be solved by the invention]

However, the conventional reel-replaceable magnetic tape device has a problem in that the quality of the reel attaching / detaching mechanism is deteriorated.
That is, with the mass production, the clutch, which is a component of the reel attachment / detachment mechanism, was changed from metal to plastic, so that the machining accuracy of the clutch became poor and the power transmission characteristics of the reel attachment / detachment mechanism deteriorated. Occur. For this reason, it is difficult to perform the tape speed control or the tape tension control with high accuracy, and erroneous recording or erroneous reading occurs in the magnetic head.

SUMMARY OF THE INVENTION An object of the present invention is to provide a reel-replaceable magnetic tape device and a control method therefor, which can prevent erroneous recording and erroneous reading of a magnetic head by controlling a tape speed and a tape tension with high accuracy, and a magnetic tape device. An object of the present invention is to provide a method for diagnosing a failure of a clutch.

[Means for solving the problem]

In order to achieve the above object, the present invention provides a detachable replacement reel, a fixed reel fixed to an apparatus main body, two motors for separately driving the replacement reel and the fixed reel, A replacement reel-side rotation speed detector that detects a rotation speed; a tension detector that detects a tension of a tape conveyed between the replacement reel and the fixed reel; and a device that records information on the tape or information from the tape. A magnetic head that reproduces or captures detection signals from the tension detector and the replacement reel-side rotational speed detector, and captures a recording or reproduction monitor signal from the magnetic head,
And a control means for controlling the rotation of the two motors based on the signals. A reel-replaceable magnetic tape device comprising: a fixed reel-side rotation speed detector for detecting the rotation speed of the fixed reel; The control means also takes in a detection signal from the fixed reel side rotation speed detector.

In this case, instead of the replacement reel side rotation speed detector,
A replacement reel-side rotation angle detector that detects the rotation angle of the replacement reel may be provided, and a fixed reel-side rotation angle detector that detects the rotation angle of the fixed reel may be provided instead of the fixed reel-side rotation speed detector. .

The present invention also provides a detachable replacement reel, a fixed reel fixed to the apparatus main body, two motors for separately driving the replacement reel and the fixed reel, and a replacement for detecting a rotation speed of the replacement reel. A reel-side rotation speed detector, a tension detector for detecting the tension of the tape conveyed between the replacement reel and the fixed reel, and a magnet for recording information on the tape and reproducing information from the tape A head, a detection signal from the tension detector and a replacement reel-side rotation speed detector, a recording or reproduction monitor signal from the magnetic head, and the two motors based on those signals. Control means for controlling the rotation, and a reel-replaceable magnetic tape device having a fixed reel-side rotation speed detector for detecting the rotation speed of the fixed reel, When the detection signal from the replacement reel-side rotation speed detector becomes abnormal, the detection signal taken into the control means is switched from the replacement reel-side rotation speed detector to the fixed reel-side rotation speed detector. A switching means is provided.

In this case, instead of the replacement reel side rotation speed detector,
A replacement reel-side rotation angle detector for detecting the rotation angle of the replacement reel may be provided, and a fixed reel-side rotation angle detector for detecting the rotation angle of the fixed reel may be provided instead of the fixed reel-side rotation speed detector. .

In addition, the present invention provides a detachable replacement reel, a fixed reel fixed to the apparatus main body, two motors for separately driving the replacement reel and the fixed reel, A tension detector for detecting the tension of the tape to be conveyed, a magnetic head for recording information on the tape or reproducing information from the tape, and a detection signal from the tension detector; And control means for controlling the rotation of the two motors based on these signals, and controlling the rotation of the two motors based on those signals. A fixed reel-side rotational speed detector for detecting the electric current, and an average value calculating means for calculating an average value of the detection signals detected by the fixed reel-side rotational speed detector. .

In this case, instead of the fixed reel side rotation speed detector,
A fixed reel side rotation angle detector for detecting the rotation angle of the fixed reel may be provided.

The present invention also provides a detachable replacement reel, a fixed reel fixed to the apparatus main body, two motors for separately driving the replacement reel and the fixed reel, and a replacement for detecting a rotation speed of the replacement reel. A reel-side rotation speed detector, a tension detector for detecting the tension of the tape conveyed between the replacement reel and the fixed reel, and a magnet for recording information on the tape and reproducing information from the tape A head, a detection signal from the tension detector and a replacement reel-side rotation speed detector, a recording or reproduction monitor signal from the magnetic head, and the two motors based on those signals. Control means for controlling the rotation, and a reel-replaceable magnetic tape device having a fixed reel-side rotation speed detector for detecting the rotation speed of the fixed reel, A vibration noise detecting means for detecting vibration noise of the drive mechanism of the replacement reel is attached, and when it is determined from the vibration noise that the drive mechanism is abnormal, a detection signal taken into the control means is transmitted to the replacement reel. A switching means for switching from the side rotation speed detector to the fixed reel side rotation speed detector is provided.

In this case, instead of the replacement reel side rotation speed detector,
A replacement reel-side rotation angle detector for detecting the rotation angle of the replacement reel may be provided, and a fixed reel-side rotation angle detector for detecting the rotation angle of the fixed reel may be provided instead of the fixed reel-side rotation speed detector. .

Further, the present invention provides a method of transporting a magnetic tape between a replacement reel and a fixed reel, monitoring recording / reproducing signals via a magnetic head, detecting the tension of the magnetic tape, and monitoring the monitor signal and the magnetic tape. When controlling the rotation of the two motors that separately drive the replacement reel and the fixed reel based on the tension detection signal, the cut-off frequency in the control loop is shifted to a low frequency side, so that the clutch The purpose is to eliminate clutch mechanism vibration noise caused by a failure in the process of determining the motor current command value.

Still further, according to the present invention, when inspecting a clutch provided in a replacement reel drive unit of a reel-replaceable magnetic tape device, a microphone is installed near the clutch,
The failure of the clutch is diagnosed by analyzing the frequency of the vibration noise of the clutch mechanism collected by the microphone.

[Action]

In the reel-replaceable magnetic tape device, erroneous recording or erroneous reading that occurs during recording or reproduction is caused by inaccuracy in tape speed control or tape tension control. Therefore, by monitoring the recording or reproduction signal via the magnetic head, the magnitude of the speed fluctuation value included in the monitor signal can be known, and the inaccuracy of the tape speed control is detected from the speed fluctuation value. It is possible.

According to the magnetic tape device having the above configuration, the rotation speed or the rotation angle of the fixed reel without the clutch mechanism can be detected, and the rotation of the motor can be controlled based on the detection result. Thus, the tape speed can be accurately controlled, and erroneous recording or erroneous reading can be avoided.

It is known that when the power transmission characteristic of the clutch is reduced, the vibration frequency of the clutch mechanism shifts to a lower frequency side. By measuring the vibration period and comparing it with the normal vibration period stored in advance, it is possible to diagnose the failure of the clutch.

In this case, the failure diagnosis of the clutch may be performed on-line from the signal being recorded or reproduced via the magnetic head, or may be performed on-line by the inspection jig in the inspection process of the magnetic tape device.

Actually, the failure diagnosis of the clutch can be executed by detecting a low-frequency shift of the frequency of the sound collected by the microphone near the clutch.

Also, when the rotation speed detector or the rotation angle detector is provided on the replacement reel side and the fixed reel side, the rotation speed detector or the rotation angle detector on the replacement reel side is normally used, and an abnormality occurs in the clutch. At this time, by switching to the rotation speed detector or rotation angle detector on the fixed reel side, it is possible to prevent the mechanical vibration noise generated due to the failure of the clutch from being mixed. As a result, the inaccuracy of the tape speed control is corrected, and erroneous recording or erroneous reading of the magnetic head can be avoided.

〔Example〕

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

(First Embodiment) FIG. 1 shows the first embodiment of the present invention and is an overall configuration diagram of a reel-replaceable magnetic tape device. In the figure, a control unit 1 is a computer including a storage unit, a calculation unit, and an input / output port, and takes in respective output signals from encoders 2 and 3, a magnetic head 4 and a tension sensor 5,
The current command value is output to the power amplifiers 6 and 7. Then, the power amplifiers 6 and 7 receive the current command value and control the motors 8 and 9 respectively. The replacement reel 10 is connected to the motor 8 via the clutch 11 and is driven to rotate by the motor 8. The fixed reel 12 is connected to the motor 9 and is driven to rotate by the motor 9.

Then, the magnetic tape 13 is replaced with the replacement reel 10 and the fixed reel 12.
And passes through the magnetic head 4 and the tension sensor 5 on the way. A monitor signal at the time of recording or reproduction is output from the magnetic head 4, and a detection signal that detects the tension of the magnetic tape 13 is output from the tension sensor 5. In addition, pulse signals are output from the encoders 2 and 3 as the motors 3 and 10 rotate.

FIG. 2 shows a procedure for operating the tape operating device of the present invention. In step 201, the replacement reel 10 including the magnetic tape 13 is mounted on the magnetic tape device. At this time, the replacement reel 10 is connected to the motor 8 via the clutch 11. Next, in step 202, the control unit 1
Replaces the magnetic tape 13 along the tape transport path
After loading from 10 to the fixed reel 12, the motors 8 and 9 are energized and tape tension is applied to prepare them for use. In this case, the control unit 1 calculates a current command value to the motors 8 and 9 for maintaining the tape tension based on the output of the tension sensor 5 and calculates the result by using the power amplifier 6 and
Output to 7.

In step 203, the control unit 1 feeds the magnetic tape 13 for recording or reproduction. At this time, the control unit 1 calculates a current command value for each motor for controlling the tape speed based on the output of the encoder 2 and outputs the result to the power amplifiers 6 and 7.

Then, in step 204, the control unit 1
The output during recording or reproduction from the magnetic head 4 is monitored,
The speed fluctuation included in the monitor signal is extracted, and it is checked whether the fluctuation value is within an allowable value that does not cause erroneous recording or erroneous reading. If no, proceed to step 205; if yes, return to step 203. The process of extracting the speed fluctuation from the monitor signal is performed by converting the monitor signal to F /
It is obtained by V-converting and comparing with a fundamental frequency whose known value is known and stored.

In step 205, the control unit 1 diagnoses the failure of the clutch 11 to check the cause of the inaccuracy of the tape speed control. If yes, proceed to step 206 to perform other processing; if no, proceed to step 207. The process of diagnosing the failure of the clutch 11 is based on the frequency ω of the vibration component from the period of the vibration included in the magnetic head output after the F / V conversion.
Is detected and compared with the normal frequency ω _n stored in advance. It is known that when there is an abnormality in the clutch 11, the frequency ω shifts to a lower frequency side, and the abnormality in the clutch 11 can be detected.

Next, in step 207, the control unit 1 performs an initial process for avoiding an abnormality of the clutch 11. clutch
The encoder 2 connected to 11 is switched to the spare encoder 3. At this time, the control unit 1 sets and stores a new flag signal indicating that the encoder 3 is being used. The spare encoder 3 is connected to the fixed reel 12 side, and the mechanical vibration noise generated due to the abnormality of the clutch 11 is not superimposed on the encoder 3, so that the mechanical vibration noise is speed-controlled via the encoder 3. Intrusion into the loop can be prevented. Further, since the tape diameter of the exchange reel 10 and that of the fixed reel 12 are different, the mechanical constants (reel radius, moment of inertia, etc.) of the fixed reel 12 are used in all subsequent processing for determining the motor current command value. Further, for the physical property data already calculated and used on the basis of the encoder 2, a process of converting and using the physical property data for the encoder 3 is performed.

Next, in step 208, the control unit 1 performs a second process for avoiding an abnormality of the clutch 11. At this time, the control unit 1 shifts the cutoff frequency of the low-pass filter in the control loop used when calculating the motor current command value to a lower frequency side. As a result, a noise signal that excites the vibration of the mechanical unit shifted to a low frequency side due to the failure of the crack 11 can be removed in the process of calculating the current command value to the motors 8 and 9, so that the tape speed control can be performed. Or, the inaccuracy of the tape tension control can be corrected.

Further, in step 203, the control unit 1 feeds the tape using the spare encoder 3.

In step 206, the control unit 1 performs another process for investigating the cause of the inaccuracy of the tape speed control. At this time, the control unit 1 checks the signals of the encoders 2 and 3 and the tension sensor 5, and sets a flag signal indicating an abnormal speed in the control unit 1.

(Second Embodiment) FIG. 3 shows a second embodiment of the present invention. This embodiment is suitable for off-line inspection in the inspection process of a magnetic tape device. The difference from FIG. 1 is that the magnetic head 4
Output from the inspection jig 17 to the control unit 1 through the output port (not shown) of the control unit 1, and the control signal m from the inspection jig 17 to the control unit 1.
And that the sound collecting microphone 16 is arranged near the clutch 11.

The operation procedure in this embodiment is basically the same as the procedure in FIG. 2, but there is a difference only in steps 204 and 205 in FIG. 2, and the difference will be described below. By the way, in order to execute the procedure of FIG. 2 off-line, it is necessary to connect the control unit 1 and the inspection jig 17, and the control signal m from the inspection jig 17 is used for this purpose.

In step 204, the inspection jig 17 analyzes the frequency of the monitor signal from the magnetic head 4 obtained via the control unit 1, measures the intensity of the speed fluctuation, compares it with a preset allowable value, If no, proceed to step 205; if yes, return to step 203.

In step 205, the inspection jig 17 diagnoses the failure of the clutch 11 in order to investigate the cause of the inaccuracy of the tape speed control. If yes, go to step 206; if no, go to step 207. Processing of the failure diagnosis of the clutch 11 detects the frequency omega obtained as a result of the frequency analysis is performed by comparing the frequency omega _n of normal.

Further, the processing of steps 204 and 205 can be executed even if the output of the microphone 16 collected near the clutch 11 is subjected to frequency analysis in the inspection jig 17.

Further, the microphone 16 may be provided in the main body of the magnetic tape device, and the microphone 16 and the control unit may be connected to each other so that the control unit 1 performs a failure diagnosis based on an output signal from the microphone 16.

Third Embodiment FIG. 4 shows a third embodiment of the present invention. The difference from FIG. 1 is that a simple encoder 18 having no speed detecting ability is provided in place of the encoder 2.

The operation procedure in this embodiment is basically the same as that in FIG. 2, but there is a difference in steps 204 and 205 in FIG. That is, in steps 204 and 205, the accuracy check of the tape speed control and the failure diagnosis of the clutch are performed on a plurality of magnetic tape devices. If the probability of occurrence of the clutch failure is high, the clutch failure is foreseen in advance to avoid the clutch failure. Precautionary measures must be implemented. In this embodiment, the control unit 1 sets and stores a flag signal indicating that the encoder 3 is being used. As a result, the mechanical constants relating to the encoder 3 and the fixed reel 12 are all used for calculating the current command value to the motors 8 and 9 in the tape feeding. 1 and 3, the mechanical vibration noise generated due to the abnormality of the clutch 11 is not superimposed on the encoder 3. Therefore, the mechanical vibration noise is transmitted through the encoder 3 in the speed control loop. To prevent intrusion into the tape, correct the inaccuracy of the tape speed control,
Erroneous recording or erroneous reading in the magnetic head 4 can be avoided.

(Fourth Embodiment) FIG. 5 shows a fourth embodiment of the present invention. 2 is different from the procedure in FIG. 2 only in that step 210 is configured instead of step 207. In step 210, the control unit 1 performs an averaging process on the detected speed value. Here, encoder 2
6 outputs a pulse signal as shown in FIG. 6, the control unit 1 calculates the tape speed Vn from the pulse cycle by the following equation (1).

Here, gamma: Reel radius N: the number of pulses t _n per one encoder: a pulse period.

The averaging process shown in FIG. 6 covers three pulses. By performing the averaging process as described above, it is possible to reduce the mechanical vibration noise superimposed on the speed detector.

In the above embodiment, the rotation speed of the replacement reel or the fixed reel is detected by the encoder. However, the rotation angle of the replacement reel or the fixed reel may be detected.

〔The invention's effect〕

As described above, according to the present invention, since the speed of the magnetic tape can be accurately controlled, erroneous recording and erroneous reading can be avoided, and the reliability of the magnetic tape device can be improved.

Further, the clutch provided on the replacement reel side can be simplified in structure, which is economical.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a magnetic tape device showing a first embodiment of the present invention, FIG. 2 is a flowchart showing an operation procedure of a control unit of FIG. 1, and FIG. 3 is a second embodiment of the present invention. FIG. 4 is an overall configuration diagram of a magnetic tape device showing a third embodiment of the present invention, and FIG. 5 is a diagram showing a fourth embodiment of the present invention. FIG. 6 is a flow chart in which the operation procedure is modified, and FIG. 6 is an explanatory diagram for explaining the averaging process in FIG. 1 ... control unit, 2, 3, 18 ... encoder, 4 ... magnetic head, 5 ... tension sensor, 6, 7 ... power amplifier, 8, 9 ... motor, 10 ... replacement reel, 11 ... ... clutch, 12 ... fixed reel, 13 ... magnetic tape, 16 ... microphone, 17 ... inspection jig.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-61-248551 (JP, A) JP-A 64-14761 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G11B 15/46

Claims (8)

(57) [Claims] 1. A detachable exchange reel, a fixed reel fixed to an apparatus main body, two motors for separately driving the exchange reel and the fixed reel, and an exchange reel for detecting a rotation speed of the exchange reel. Side rotation speed detector, a tension detector for detecting the tension of the tape conveyed between the replacement reel and the fixed reel, and a magnetic head for recording information on the tape and reproducing information from the tape Detecting signals from the tension detector and the rotation speed detector on the replacement reel side, and capturing monitor signals for recording or reproduction from the magnetic head, and rotating the two motors based on the signals. And a control means for controlling the rotation of the fixed reel, wherein a fixed reel-side rotation speed detector for detecting a rotation speed of the fixed reel is provided, and Switching means for switching a detection signal taken into the control means from the replacement reel-side rotation speed detector to the fixed reel-side rotation speed detector when a detection signal from the replacement reel-side rotation speed detector becomes abnormal. A reel-replaceable magnetic tape device comprising: 2. An exchange reel which is detachable, a fixed reel fixed to the apparatus main body, two motors for separately driving the exchange reel and the fixed reel, and an exchange reel for detecting a rotation angle of the exchange reel. Side rotation angle detector, a tension detector for detecting the tension of the tape conveyed between the replacement reel and the fixed reel, and a magnetic head for recording information on the tape and reproducing information from the tape Detecting signals from the tension detector and the rotation angle detector on the replacement reel side, and capturing monitor signals for recording or reproduction from the magnetic head, and rotating the two motors based on the signals. And a control means for controlling the rotation of the fixed reel. The fixed reel-side rotation angle detector for detecting the rotation angle of the fixed reel is provided, and the replacement reel is provided. When the detection signal from the side rotation angle detector becomes abnormal, switching means is provided for switching the detection signal taken into the control means from the replacement reel side rotation angle detector to the fixed reel side rotation angle detector. An exchangeable magnetic tape device characterized by the following features. 3. A detachable replacement reel, a fixed reel fixed to the apparatus main body, two motors for separately driving the replacement reel and the fixed reel, and a transfer between the replacement reel and the fixed reel. A tension detector that detects the tension of the tape to be performed, a magnetic head that records information on the tape or reproduces information from the tape, and takes in a detection signal from the tension detector. A control means for taking in monitor signals for recording or reproduction and controlling the rotation of the two motors based on the signals, and detecting a rotation speed of the fixed reel. And a mean value calculating means for calculating an average value of the detection signal detected by the fixed reel-side speed detector. Reel exchangeable magnetic tape device. 4. A detachable replacement reel, a fixed reel fixed to the apparatus main body, two motors for separately driving the replacement reel and the fixed reel, and a transfer between the replacement reel and the fixed reel. A tension detector that detects the tension of the tape to be performed, a magnetic head that records information on the tape or reproduces information from the tape, and takes in a detection signal from the tension detector. A control means for taking in monitor signals for recording or reproduction and controlling the rotation of the two motors based on the signals, and detecting the rotation angle of the fixed reel. And a mean value calculating means for calculating an average value of detection signals detected by the fixed reel-side rotation angle detector. Reel replaceable magnetic tape device. 5. A detachable replacement reel, a fixed reel fixed to the apparatus main body, two motors for separately driving the replacement reel and the fixed reel, and a replacement reel for detecting a rotation speed of the replacement reel. Side rotation speed detector, a tension detector for detecting the tension of the tape conveyed between the replacement reel and the fixed reel, and a magnetic head for recording information on the tape and reproducing information from the tape Detecting signals from the tension detector and the rotation speed detector on the replacement reel side, and capturing monitor signals for recording or reproduction from the magnetic head, and rotating the two motors based on the signals. And a control means for controlling the rotation of the fixed reel, wherein a fixed reel-side rotation speed detector for detecting a rotation speed of the fixed reel is provided, and A vibration noise detecting means for detecting vibration noise of the drive mechanism of the replacement reel is attached, and when it is determined from the vibration noise that the drive mechanism is abnormal, a detection signal taken into the control means is transmitted to the replacement reel side rotation. A reel-replaceable magnetic tape device, comprising: switching means for switching from a speed detector to the fixed reel-side rotation speed detector. 6. A detachable replacement reel, a fixed reel fixed to the apparatus main body, two motors for separately driving the replacement reel and the fixed reel, and a replacement reel for detecting a rotation angle of the replacement reel. Side rotation angle detector, a tension detector for detecting the tension of the tape conveyed between the replacement reel and the fixed reel, and a magnetic head for recording information on the tape and reproducing information from the tape Detecting signals from the tension detector and the rotation angle detector on the replacement reel side, and capturing monitor signals for recording or reproduction from the magnetic head, and rotating the two motors based on these signals. And a control means for controlling the rotation of the fixed reel. The fixed reel-side rotation angle detector for detecting the rotation angle of the fixed reel is provided, and the replacement reel is provided. When vibration noise detection means for detecting vibration noise of the drive mechanism is mounted, and when the drive mechanism is determined to be abnormal based on the vibration noise, a detection signal taken into the control means is detected by the replacement reel side rotation angle detection. A reel-replaceable magnetic tape device, further comprising switching means for switching from a device to the fixed reel side rotation angle detector. 7. A magnetic tape is transported between a replacement reel and a fixed reel, a recording / reproducing signal is monitored via a magnetic head, a tension of the magnetic tape is detected, and the monitor signal and the magnetic tape tension are detected. Based on the detection signal of
When controlling the rotation of two motors separately driving the replacement reel and the fixed reel, the cut-off frequency in the control loop is shifted to a lower frequency side, so that a clutch mechanism vibration noise caused by a clutch failure is generated. In a reel-replaceable magnetic tape device, which eliminates the above in the process of determining the motor current command value. 8. When inspecting a clutch provided in a replacement reel drive unit of a replaceable magnetic tape device, a microphone is installed near the clutch, and vibration noise of the clutch mechanism collected by the microphone is collected. A method of diagnosing a clutch failure in a reel-replaceable magnetic tape device, wherein the clutch is diagnosed by analyzing the frequency of the clutch.