JPH0520727A - Stepwise winding preventing device for reproducing magnetic tape - Google Patents

Abstract

PURPOSE:To easily eliminate a steplike state of a tape by detecting the occurrence of the steplike state from an increase of torque, fast forwarding the tape after stopping the present processing, bringing the tape back to a position prior to the stopping and starting restoring processing. CONSTITUTION:The torque at the time of becoming the steplike state of the tape is measured in advance, and the torque under the commencing state of the steplike state is regarded as warning torque TA. When torque of a DC motor 11 is denoted as TB, if TA>TB, tape access is continued, and if TA<=TB, the present position and an access mode, etc., are stored via a rotary drum, and a retention operation is started. Then, when the beginning of the tape 5 is detected by a position detector 23, the drive of a DC motor 20 is stopped, and a DC motor 10 is driven to read out a data of the rotary drum, and the tape is restored to the position prior to the above retention, and then the restoring processing is commenced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic tape reproducing device. In particular, the present invention aims to prevent step winding that occurs due to partial repetition of winding and rewinding of the tape.

[0002]

2. Description of the Related Art A magnetic tape reproducing apparatus includes an apparatus for reproducing what is stored on a recording tape as a sound waveform as an analog signal or a digital signal, and an apparatus for similarly reproducing an image stored. These magnetic tape reproducing devices are equipped with a reel for winding the tape and a reel for supplying the tape.

[0003]

However, in the conventional magnetic tape reproducing apparatus, there is no problem in reproducing the tape continuously, but when the winding and rewinding are partially repeated, the tape is wound. A number of step winding states occur in the state, and the convex part comes into contact with the case storing the tape,
There is a problem in that not only winding, but also rewinding and fast-forwarding may not be possible. In such a case, in order to correct the wound state, the user manually performs fast forward, rewind, etc. of the tape several times to remove the wound state.

Therefore, in view of the above problems, it is an object of the present invention to provide a multi-winding prevention device for magnetic tape reproduction which can easily remove the multi-winding state.

[0005]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention relates to a drive unit of a reel for winding a tape in a magnetic tape reproducing apparatus having a reel for winding a tape and a reel for supplying the tape. A torque detector is installed in.

[0006]

According to the magnetic tape reproducing step winding prevention device of the present invention, the warning torque immediately before the step winding state is generated is detected by the torque detector during the repeated processing of winding and rewinding the tape. When the torque is detected, the above process is interrupted, the tape is fast forwarded, rewound after winding, and then the above process interruption is released, so that the tape winding state can be easily removed. It was

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an outline of a magnetic tape reproducing apparatus which is a premise of the present invention. The configuration of this figure will be described. The magnetic reproducing apparatus shown in the figure includes a take-up reel 1 and a supply reel 2.
A control unit 3 for controlling reproduction of the magnetic tape, a rotary head 4 for tracing on a precisely recorded track, a tape 5 for storing digital data, a take-up reel 1 and a supply reel 2. Case 6 and tape 5
Includes a cap stan 41 for keeping the speed constant, a pinch roller 42 sandwiching the cap stan 41 and the tape 5, and other guide rollers 43, 44, 45, 46 and the like.

FIG. 2 is a diagram showing a drive unit of the reel shown in FIG. In the configuration of this drawing, a DC motor 10 for driving the take-up reel 1, a shunt winding exciting coil 11 of the dc motor 10, a variable resistor 12 for adjusting an exciting current of the shunt winding exciting coil, and a tape for the take-up reel 1 Position detector 13 to detect the end position
And a switch 14 for turning the supply voltage on and off, and a DC motor
10, a voltage source 15 for supplying electric power to the DC motor 10, an ammeter 7 for detecting the armature current of the DC motor 10, a DC motor 20 for driving the supply reel 2, and a shunt winding coil 21 for the DC motor 20.
And a variable resistor 22 connected in series with the shunt excitation coil 22.
The position detector 23 for detecting the starting position of the tape on the supply reel 23, and the switch 24 for turning on and off the supply voltage from the voltage power supply 15 to the DC motor 20 are included. The signals from the position detectors 13 and 23 are input, and the operations of the switches 14 and 24 and the variable resistor 12 are controlled based on these signals.

Next, a series of operations will be described. FIG. 3 shows the present invention
It is a figure explaining a series of operation | movement which concerns on. As shown in this figure
During the tape access (step 1),
Switch 14 to ON, switch 24 to OFF, and
Flow motor 10 is supplied with armature current, and
The exciting current is supplied to the coil 11 and the tape 5 becomes the take-up reel.
It is wound up. Switch 14 OFF when rewinding
Switch ON the switch 24 to turn on the DC motor 20 armature.
The current is supplied, and the excitation current is supplied to the shunt excitation coil 21.
Be done. When the above winding and rewinding are repeated
Armature current I of DC motor 11 on the winding side_BTo ammeter 7
Therefore, the detected current I_BInput to the control unit 3
It is converted into the torque of the DC motor 11 by the controller 3. this
The torque is the armature current I_BIt is proportional to_BTosu
It Measure the torque when the tape is wound in advance
The warning torque T
_AAnd T_A> T_BIn case of, continue tape access
Yes (step 2), T _A≤T_BIn case of
Device, access mode, etc. are stored via the rotating drum
(Step 3), start the retention operation (
Step 4). Here the retention operation is to the end of the tape
After fast-forwarding, a series of operations to rewind to the beginning of the tape
is there. This operation will be described below. During retention
At step 5), the controller 24 turns off the switch 24.
Then, turn on the switch 14 to adjust the variable resistor 12 and shunt
To reduce the exciting current to increase the number of revolutions and
It The end of the tape 5 is detected by the position detector 13.
Then, the control unit 3 turns off the switch 14,
Turn on the switch 24 to turn on the armature and the shunt excitation coil of the DC motor 20.
Winding tape 5 on supply reel 20 by supplying current to the reel
Return (step 7). Tape by position detector 23
When the starting point of 5 is detected (step 8), the DC motor 20
Drive the DC motor 10 to
Read the data of the system, return to the position before retention,
The restoration process is started (step 9). In addition, tape access
If it is not in progress or retention, a series of
The operation ends. Furthermore, the ammeter 7 is connected to the DC motor 20.
Even if it is provided, the same effect can be obtained. In addition, the DC motor
Although the description has been made on the shunt winding type, the present invention is not limited to this.

[0010]

As described above, according to the present invention, the occurrence of the step winding state is detected by the increase of the torque, and when the occurrence is detected, the processing is temporarily stopped, the tape is fast forwarded, and after the winding. Since the tape is rewound and the return process is started at the position before the interruption, the tape winding state can be easily removed.

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of a magnetic tape reproducing apparatus which is a premise of the present invention.

FIG. 2 is a diagram showing a drive unit of the reel of FIG.

FIG. 3 is a flowchart illustrating a series of operations according to the present invention.

[Explanation of symbols]

 1 ... Take-up reel 2 ... Supply reel 3 ... Controller 4 ... Rotating drum 5 ... Tape 6 ... Case 7 ... Torque detector

Claims (1)

Claim: What is claimed is: 1. A magnetic tape reproducing apparatus having a reel (1) for winding a tape and a reel (2) for supplying the tape, wherein a drive unit of the reel (1) for winding the tape. A torque detector (7) is provided in the tape, and when the torque value detected by the torque detector (7) exceeds a predetermined value, the take-up reel (1) is fast forwarded to wind the tape, and then the tape is supplied. A multi-winding prevention device for magnetic tape reproduction, which rewinds to a reel and, after rewinding, returns to a forward fast-forward start position to start a reproduction process.