JPH11250529A - Magnetic tape unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restore a tape to the state before the power supply is interrupted by safely unwinding the slack in the tape which is generated by the interruption of power supply, without giving damage to the tape. SOLUTION: The detection of the positions of movement guiding system 8, 9, 10, 11 is performed during the initial operation after the power is supplied, but the following tape unwinding process is executed since there is the possibility of generating the slack of tape in the case other than the tape unloading state. After the stopping state of the rotation of a rotary drum 4 is confirmed, the movement guiding systems 8, 9, 10, 11 are returned to the direction of the position in the tape unloading state. By driving a reel 3 of the take-up side at the same time, the elimination of the tape slack is started. At this time, the reel 2 of the supply side is being in the free state (free rotation). The movement guiding systems 8, 9, 10, 11 are stopped at the prescribed position advantageous as to the tape protection. The tape winding angles on the rotary drum 4 becomes small at these movement guiding positions, so the interaction of tape-rotary drum due to the friction is hardly generated. The eliminating operation of the tape slack is completed in this state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic tape drive for driving a magnetic tape for recording and reproducing magnetic signals,
In particular, the present invention relates to a helical scan type magnetic tape device using a rotating drum.

[0002]

2. Description of the Related Art Heretofore, attention has been paid to the danger of power interruption occurring during tape transfer. Since the reels on the tape supply side and the winding side become uncontrollable due to power cutoff during the tape transfer, there is a possibility that the tape may be slackened or the tape may be subjected to excessive tension. In particular, in a commercial VTR or the like, since the diameter of each reel is large, the influence of the inertia of the reel when control becomes impossible is large, and therefore, there is a high risk of tape damage. In order to prevent such tape damage, some commercial VTRs are provided with mechanical braking means that operates when power is shut off on each reel.

[0003]

In recent years, the size and cost of magnetic tape units for computers have been reduced due to the demand for downsizing. Therefore, it is necessary to reduce the number of parts, and it is not appropriate to provide a mechanical brake mechanism for shutting off the power supply as described above. However, if the tape can be returned from the sagging state without damaging the tape when the power is cut off during the tape transfer, a certain amount of tape slack can be allowed. At this time, the tape running system is required to have a function of restraining the tape to some extent in the tape width direction so that the tape returns to the inside of the reel by the reel winding operation after the power is restored even if the tape sags. You.

In the case of a magnetic tape device using a specific cassette, the maximum value of the tape slack can be predicted within a certain range, but the slack state is the tape running direction, the tape speed, and the diameter of each reel (tape winding amount). Changes under the influence of In other words, in the tape running system, there is a case where the tape slacks around the supply reel of the cassette and a case where the tape slacks around the reel of the take-up side of the cassette. At this time, if it is attempted to wind the tape on only one of the reels without any special consideration, it is considered that the tape may move on the rotating drum.

After the power is turned off, the upper portion (upper drum) of the rotating drum is in a free state (free) in the rotating direction. At this time, when the tape moves on the rotating drum and the frictional force between the tape and the rotating drum is large, the upper drum, which has been freely rotated, starts rotating under the influence of the movement of the tape. When the upper drum starts rotating in this way,
This time, a frictional force is applied to the tape, but the speed direction on the upper drum surface has a certain angle to the speed direction of the tape movement. In the width direction. This risks damaging the tape.

SUMMARY OF THE INVENTION It is an object of the present invention to allow a certain amount of tape slack in a power supply interruption and complete a recovery operation for rewinding a tape without damaging the tape and returning to a tape transferable state. The objective is to supply a low-cost and highly reliable magnetic tape device.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide two reel motors for driving a tape, a rotation detector provided on at least one of the reels and detecting rotation of the motor, a moving guide, a moving guide driving mechanism, and a reel. This is achieved by a controller that controls the rotation of the motor and the movement of the movement guide. The outline of the operation is shown below.

After the power is turned on, a predetermined initial operation is performed. During this operation, the controller detects the position of the moving guide system. When the position of the movement guide system is other than the tape unloading state, the state before the power was turned off could not be specified, and the tape may have slack in the device. I do.

After confirming that the rotation of the rotary drum has stopped, the moving guide system is returned to the direction of the tape unloading position. At the same time, by driving the take-up reel, the slack of the tape is started. At this time, the supply reel is in a free (rotatable) state. When moving the moving guide system, the frictional force between the tape and the rotating drum is reduced by intermittently moving the moving guide system. The moving guide stops at a predetermined position which is advantageous with respect to the tape protection. At this movement guide position, the tape winding angle of the rotating drum is small, and almost no tape-rotating drum interaction due to friction occurs. In this state, the tape slack removal operation is continued, but the presence or absence of the tape slack is determined by monitoring the rotation of the supply-side reel that is not driven, and the slack removal operation is terminated when it is determined that the tape slack has disappeared. .

As described above, since the tape-rotating drum interaction is prevented from occurring, the tape can be safely rewound into the reel without causing tape damage due to the interaction. .

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described based on embodiments.

FIG. 1 is a perspective view of a magnetic tape device according to the present invention. In the drawing, the cassette 16 indicated by a broken line is replaceable, and includes an S reel 2 (supply reel) and a T reel 3 (winding reel), and the tape 5 is wound around each reel. The cassette 16 is inserted into the apparatus from the outside, and then the tape 5 inside the cassette is positioned so as to be wound around the rotating drum 4 after being pulled out of the cassette. Hereinafter, the tape positioning operation is referred to as a tape loading operation, and the operation of returning the tape 5 into the cassette 16 is referred to as a tape unloading operation.

FIG. 1 shows a state in which the tape loading operation has been completed. In this state, the tape 5 is transferred from the S reel 2 to the T reel 3 in order to input and output a magnetic signal. At the time of tape transfer, the tape 5 comes out of the cassette 16, and the guide 6, the guide 17, the guide 7, the moving guide 8, the moving pin 9, the rotating drum 4, the moving pin 10,
After moving guide 11, guide 12, and guide 13, T
It is wound on a reel 3. A magnetic head (not shown) is provided on a rotating portion of the rotating drum 4, and inputs and outputs a magnetic signal to and from the tape 5. In addition, main components other than the movable components such as the movement guide are fixed to the chassis 1.

FIG. 2 is a plan view for explaining a main part of the magnetic tape device of the present invention. FIG. 2 shows a state immediately after the cassette 16 is mounted in the apparatus and before the tape loading operation. Hereinafter, this state is called a tape unloading state.

The moving guide 8 and the moving pin 9 are set on the moving base 26, and move together during the tape loading operation. The circular member 2 is placed at a predetermined position below the moving base 26 so that the moving base 26 can move along the groove 30 of the base member 15 and the groove 31 of the base member 18.
7 is connected. Moving guide 11, moving pin 10,
The configurations of the moving base 29 and the circular member 28 are the same as those of the above-described moving guide structure, and the moving base 29 is movable along the groove 32 of the base member 15 and the groove 33 of the base member 18. The rotational force of the tape loading motor 25 is transmitted to the moving bases 26 and 29 by a gear mechanism or the like (not shown) and moves them simultaneously. The gear mechanism simultaneously drives the rotary switch 14 to rotate. By the output of the rotary switch 14, the controller can detect the approximate position of the moving bases 26 and 29.

As shown in FIG. 2, each moving guide is located around the cassette 16 in the tape unloading state. A reel motor 21 and a reel motor 23 are provided below the S reel 2 and the T reel 3, respectively, and each reel is driven. The reel motors 21 and 23 are provided with rotation speed detectors 22 and 24, respectively.

FIG. 3 is a plan view showing the position of each tape guide and the tape running path in the tape unloading state. Immediately after the cassette 16 is inserted from the outside and set in the apparatus, the state is as shown in FIG. The moving guide 8, the moving pin 9, the moving pin 10, and the moving guide 11 are located near the cassette 16 and at a location surrounded by the tape 5. When the tape loading operation is started, the moving bases 26, 29 are moved along the grooves 30, 32 as described with reference to FIG.
Move, the moving guide 8 and the moving pin 9 are indicated by arrows 3
6, the moving guide 11 and the moving pin 10 are indicated by arrows 3
Move in the direction of 7. Thereby, the tape 5 is pulled out from the cassette and finally wound around the rotating drum 4.

FIG. 4 is a plan view showing the position of each tape guide and the tape running path when the tape loading operation is completed and the tape 5 is wound around the rotary drum 4. Hereinafter, this state is referred to as a tape loading completed state. At this time, each moving guide is at a predetermined position for performing a tape transfer operation, and the tape 5 is wound around the rotary drum 4 at a predetermined angle (about 230 ° in this embodiment).

During the tape loading operation and the tape unloading operation, the S-reel 2 and the T-reel 3 each generate a torque in a direction for applying a tension to the tape, so that the tape does not sag. Also, during the tape transfer operation, the S reel 2 and the T reel 3 are controlled so that the tape tension is constant, so that the tape does not sag. However, if the power is interrupted during the tape transfer operation, the control of both reels becomes impossible, and the tape may be slackened. Especially in a configuration where no mechanical brake is attached to each reel due to cost restrictions, if power is cut off while the tape is being transported at high speed, the rotation of the tape continues for a while due to the inertia of the reel, and the tape sags. There is a risk that the amount will be large.

FIG. 5 shows an example of a tape state after a power supply interruption in the forward direction, that is, in a state where the tape 5 is being transferred from the S reel 2 to the T reel 3 at a high speed. The tape 5 is mainly the S reel 2 on the side that sends out the tape.
There is a large slack in the vicinity. However, since the tape slack around the reel occurs inside the cassette 16, the tape is not damaged in most cases in the process of the tape slack. Although tape slack sometimes occurs outside the cassette 16, it has been experimentally found that a small amount of tape slack occurs in the section between the guide 7 and the rotary drum 4 as shown in FIG. Also, almost no tape sag occurs on the T reel 3 side. As described above, the tape sag occurs locally. This is because, after the power supply of the tape in the magnetic tape device has been cut off, the running is stopped immediately by the frictional force from the guide in the running system, while the reels are stopped. Is caused by the fact that rotation continues for a while due to inertia. That is, the tape on the T reel side is wound on the T reel 3, but the tape on the S reel side is fed out from the inside of the S reel 2.

FIG. 6 shows an example of the state of the tape after the power is turned off in the reverse direction, that is, in the state where the tape 5 is being transferred from the T reel 3 to the S reel 2 at high speed. The tape 5 is mainly a T reel 3 on the side from which the tape is sent.
There is a large slack in the vicinity. Also, a small amount of tape slack is generated in a section between the rotary drum 4 and the guide 13.

As described above, FIGS. 5 and 6 show two tape slack states when the power is cut off. These are typical examples when the power is cut off during the forward running or the reverse running, and the tape slack state includes the tape winding amount of the S reel 2 and the T reel 3, the tape transfer speed, the friction state, and the like. Changes under the influence of However, if the tape can be rewound safely even in the state where the slack amount is the largest, it is possible to recover from any possible tape slack state.

FIG. 7 is a perspective view showing the structure of the rotary drum 4. The rotating drum 4 is roughly classified into an upper drum 41 that rotates at a high speed during operation and a fixed lower drum 42. The lower drum 42 is fixed to the chassis 1 via a drum base 43. The shaft 46 is fixed to the lower drum 42. The upper drum 41 is a ball bearing (not shown)
, And is rotatably attached to a shaft 46 via a shaft motor, and is rotatably driven at high speed by a drum motor (not shown).

In this embodiment, a plurality of magnetic heads 45 are dispersedly provided around the lower edge of the upper drum 41, and rotate at high speed integrally with the upper drum 41. Lower drum 4
2 is provided with a lead portion 44 having a slightly larger diameter, and the tape runs with the lower end of the tape 5 along the lead 44. The rotation locus of the magnetic head 45 and the tape running direction running along the lead 44 are set to be at a predetermined angle. Further, by synchronizing the tape running and the rotation of the rotary drum 4, the magnetic head 45 5 is always scanned at a fixed angle. The above configuration is a known technology widely used as a helical scan system in a VTR deck or the like.

FIG. 8 is a diagram for explaining the interaction between the tape and the rotating drum. For the sake of explanation, the tape 5 is shown in a two-dimensionally developed manner, and the drawing is not accurate in terms of dimensions, coordinates, and the like. Actually, as described above, the tape 5 is attached to the rotating drum 4 at a predetermined angle (about 23 in this embodiment).
0 °). (See FIG. 1.) When the power is cut off, the tape sags as described above, and it is necessary to rewind the tape on the reel. In the process of performing the tape rewinding operation, the tape 5 moves in a certain direction around the drum, which may cause a tape damage.
This will be described with reference to FIG.

After the power supply is shut off, the drum motor for rotating the upper drum 41 is also turned off, so that the upper drum 41 connected to the shaft 46 via the ball bearing is in a free state (free) in the rotation direction. If the tape rewind operation is performed by driving the T reel to wind up the slack that has occurred on the S reel side, for example, the tape 5 may move on the drum. At this time, if the frictional force between the tape and the rotating drum is large, the upper drum 41, which is in a freely rotatable state, starts to rotate due to the movement of the tape 5. Thus, the upper drum 41
When this rotates, a frictional force is applied to the tape 5 in reverse. Here, the velocity direction 4 on the surface of the upper drum 41
Numeral 7 has a certain angle with respect to the speed direction 48 (longitudinal direction) of the movement of the tape 5, and the difference between the speed directions acts as a frictional force for moving the tape 6 in the width direction (upward in FIG. 8). . This tape 6 is made up of guides 8 and 11 (FIG. 1)
The position in the width direction is regulated by the flange member provided in
If it becomes large, the tape 6 will in most cases buckle in the flange member, resulting in damage.

The risk of tape damage during the tape rewinding operation has been described above. In this embodiment, the tape is rewound without causing the tape-rotating drum interaction to avoid tape damage. Hereinafter, this will be described.

FIG. 9 shows a configuration including the flow of signals in the tape loading device of the present invention. The controller 61 includes a memory, an arithmetic unit, and the like, and operates based on a clock from a clock generator (not shown).

The controller 61 includes a reel motor 21,
The drive signals 73 and 74 of the motor 23 are output, and the motor drive signals are amplified by the reel motor drivers 62 and 63, respectively, and then input to the reel motors 21 and 23. Supply-side reel motor 21 detected by rotation speed detector 22
The rotation speed signal 72 of the winding-side reel motor 23 detected by the rotation speed detector 24 and the rotation speed signal 75 of
It is input to the controller 61.

The controller 61 outputs a drum drive signal 71. The motor drive signal is amplified by a drum motor driver 64 and then input to a drum motor 66. The rotation speed signal 77 of the rotating drum 4 detected by the rotation speed detector 67 is input to the controller 61. The controller 61 outputs a TL (tape loading) motor drive signal 78.
Is input to The driving force of the tape loading motor 25 is transmitted by a gear mechanism to rotate the rotary switch 14, and further transmitted by another gear mechanism to move the moving guide 8, the moving base 26 on which the moving pin 9 is mounted, and the moving pin 10, The moving base 29 on which the moving guide 11 is mounted is simultaneously driven.

Hereinafter, the moving guide 8, the moving pin 9, the moving base 26, the moving pin 10, the moving guide 11, and the moving base 29, which are the moving guide members, are collectively referred to as a moving guide system.

The amount of rotation of the rotary switch 14 is input to the controller 61. Since the amount of rotation of the rotary switch and the amount of movement of the moving guide system are substantially proportional,
The controller 61 can detect the approximate position of the movement guide system.

Next, referring to FIG. 10, an initial operation flow including a tape rewinding process performed after the power is turned on will be described.

In step S2, a self-diagnosis of the magnetic tape device controller is performed. If it is determined that the controller is abnormal, the process proceeds to step S8, where the content of the abnormality is reported to the host computer, and the process is interrupted.
If it is determined that it is normal, the process proceeds to step S3, where the rotary switch 14 provided for detecting the position of the movement guide
Check output. If it is determined here that there is an abnormality, the process proceeds to step S8. The processing at the time of the abnormality is all the same as the above-described processing, and thus the description is omitted.

If it is determined in step S3 that the operation is normal, the process proceeds to step S4, where the driving circuit of the loading motor 25 for moving the moving guide is checked. Step S4
If it is determined that is normal, the process proceeds to step S5, and the position of the movement guide system is detected from the output of the rotary switch 14. In this case, any one of the three states, that is, the tape unloading state, the tape loading completed state, and the indefinite state is detected. When the moving guide system is located between the tape unloading state and the tape loading completed state, the rotary switch 14 is set to output an indefinite state. If it is determined that the position of the movement guide system is in the tape unloading state, step S
Go to 7. If the status is other than the tape unloading status, that is, if the tape loading is completed or the status is undefined, the status before the power is turned off cannot be determined, and there is a possibility that tape slack has occurred in the device. Proceeding to S6, a tape rewinding process is performed. Although the details of the tape rewinding process S6 will be described later, when this process ends, the movement guide system enters a tape unloading state. Thereafter, the process proceeds to step S7. In step S7, the output of the tape end detection sensor for optically detecting the end of the tape is checked. If it is determined to be abnormal, the process proceeds to step S8. When it is determined that the magnetic tape device is normal, the process proceeds to step S25, and the host is notified that the magnetic tape device is normal, and the initial operation ends.

Next, the details of the tape rewinding process shown in step S6 of FIG. 10 will be described with reference to FIG.

First, it is confirmed in step S12 that the rotation of the rotary drum 4 has stopped. Next, in step S13, the drive of the tape loading motor 25 is started, and the motor 25 rotates in a direction to return the movement guide system to the position in the tape unloading state.

Next, proceeding to step S14, the controller 61 waits for a predetermined time while monitoring the timer. This waiting time is provided because there is a slight time delay from when the tape loading motor 25 starts to be driven to when the movement guide system starts to move due to mechanical factors. Next, the process proceeds to step S15, in which the slack of the tape is started by driving the T reel 3. At this time, S reel 2
Is in a free (rotatable) state. Next, in step S16, the drive signal 78 input to the tape loading motor 25 is turned ON / OFF at regular intervals, and
Is driven intermittently. In response to this, the movement guide system moves intermittently.
The state in which the tape 5 and the rotary drum 4 are in close contact with each other is prevented from continuing. As described with reference to FIG. 8, the primary cause of tape damage is the interaction between the tape and the rotating drum. By performing the above-described operation, the frictional force between the tape and the rotating drum is reduced. Tape damage due to the interaction can be avoided.

Next, after waiting a predetermined time in step S17, the tape loading motor 25 is stopped in step S18, and each of the moving guides 8, 9, 10, 11 is stopped.
Is stopped at a predetermined position. The position of each movement guide at this time will be described later with reference to FIG.

Next, proceeding to step S19, a pulse signal (FG pulse) output from the S reel rotation speed detector 22
Is started, and the rotation amount of the S reel is detected. In step S20, it is determined whether or not the S reel 2 has rotated by a predetermined amount or more. If it is determined that the S reel 2 has rotated by the predetermined amount or more, the process proceeds to step S21, and the tape slack removal processing ends. Until now, the reel motor 21 for driving the S reel 2 has been in an OFF state, and the rotation of the S reel 2 is because the tension of the tape 5 is acting on the S reel 2, that is, the tape slack is eliminated. It indicates that. If it is determined in step S20 that the rotation of the S reel 2 has not reached the predetermined amount,
Continue the slack removal operation.

In step S21, a tape unloading operation is performed. Specifically, the operation is as follows. S
A predetermined torque is generated on the reel 2 and the T reel 3 in a direction in which the tape 5 is rewound into each reel. As a result, a tape tension is generated. At the same time, the tape loading motor 25 is driven to return the moving guide to the position in the tape unloading state. Thus, the tape 5 is rewound into the S reel 2 or the T reel 3. When this operation is completed, the entire tape rewinding operation ends in step 32.

In the tape rewinding operation flow described with reference to FIG. 11, the moving guide was returned to a predetermined position to remove the slack of the tape. FIG. 12 shows the position of each movement guide at this time.

Moving guides 8, 11, moving pins 9, 10
Is considerably close to the cassette 16, but has not reached the tape unloading state. At this time, the tape running path from the guide 17 on the left side of the rotary drum 4 to the guide 13 on the right side has a nearly linear shape as shown in the figure. Although the tape 5 is in contact with the rotating drum 4, the tape winding angle on the rotating drum 4 is considerably small. (In this embodiment, it is about 30 °.) In such a state where the winding angle is small, the contact area between the tape and the surface of the rotating drum becomes small, and the tape-rotating drum interaction described with reference to FIG. Rarely occurs.

The embodiment of the magnetic tape device according to the present invention has been described above. According to the present embodiment, after the power interruption occurs, the tape is taken up by moving the moving guide system in the tape unloading state direction in the process of the slack removal processing.
Since the contact area between the tape and the rotating drum is reduced and the above-mentioned interaction between the tape and the rotating drum is prevented, the tape can be safely rewound into the reel without causing tape damage. Further, since no additional parts such as a mechanical brake of the reel motor are required, the apparatus can be constructed at low cost.

Next, another embodiment of the magnetic tape device of the present invention will be described.

FIG. 13 is a plan view showing another embodiment of the magnetic tape device of the present invention. In the present embodiment, a tape guide 81 with a speed detector is added to the tape guide on the right side of the rotary drum 4 with the function of detecting the tape speed. The other configuration is the same as that of the previous embodiment, and the description is omitted.

FIG. 14 shows a tape guide 81 with a speed detector.
FIG. A shaft 83 is attached to a disc-shaped base 82.
Has been fixed. The roller portion 84 has a hollow cylindrical shape, but is rotatably attached to the shaft 83. The outer cylindrical surface of the roller portion 84 comes into contact with the tape 5, but the surface of the roller portion 84 is processed to increase the friction so as not to cause slippage with the tape 5. . An encoder disk portion 87 is provided inside the upper flange portion 85, and the encoder disk portion 87 is fixed to a roller portion 84 by a connecting member 86, and the roller portion 84 and the encoder disk portion 87 are fixed. Rotates integrally with the running speed of the tape 5. The rotation of the encoder disc 87 is converted into an electric signal by an encoder rotation detector 88 fixed to the upper flange 85 and sent to the controller 61. In the present embodiment, the rotation of the roller portion 84 of the tape guide is detected using an encoder, but a magnetic signal generator (function generator) or the like may be used for this.

Next, the flow of the tape rewinding operation of the present embodiment when the power is cut off will be described with reference to FIG.
Note that, as in the previous embodiment, the state illustrated in FIGS. 5 and 6 is assumed as the tape state in the initial operation. Also,
The tape rewinding operation is performed in the initial operation flow of the magnetic tape device described with reference to FIG.

In step S32, driving of the T reel 3 is started. As a result, the tape slack generated by the power interruption is returned to the T reel 3. At this time, in order to avoid tape damage, it is desirable that the rotation speed of the T reel 3 is sufficiently low. The S reel 2 is in a free (rotatable) state. After step S32, the controller 61 monitors the tape speed signal output from the tape guide 81 with the speed detector. Proceeding to step S33, a judgment is made on the tape speed detected by the tape guide 81 with the speed detector. When the tape speed is equal to or lower than the predetermined threshold, the tape reeling with the T reel 3 is continued. If the tape speed is equal to or higher than the predetermined threshold value, the process proceeds to step 34, where the T reel 3 is stopped.

The fact that the speed of the tape 5 is detected by the tape guide 81 when the T reel 3 is driven means that the T
This indicates that the tension has been transmitted from the reel 3 to the tape 5. That is, by detecting the tape speed, it can be determined that the tape slack on the T reel side has been eliminated.

Next, an operation of removing the slack on the S reel 2 side is performed. In step S35, driving of the S reel 2 is started. Here, to avoid tape damage, the S reel 2
Is desirably sufficiently low. Further, the T reel 3 is in a free (rotatable) state.

In step S36, a judgment is made on the tape speed detected by the tape guide 81 with the speed detector. If the tape speed is equal to or lower than the predetermined threshold, the tape reeling by the S reel 2 is continued. If the tape speed is equal to or higher than the predetermined threshold value, the process proceeds to step 37, where the S reel 2 is stopped. As described above, the slack on the S reel 2 side can be removed by the operations from step S35 to step S37. The algorithm for judging the end of slack removal on the S reel side is the same as that for the slack removal on the T reel side, and therefore the description thereof is omitted. Further, in the present embodiment, the slack removing process on the S reel is performed after the slack removing process on the T reel side. Processing may be performed.

Next, proceeding to step S38, a tape unloading operation is performed, which is the same as in the previous embodiment. A predetermined torque is generated on the S reel 2 and the T reel 3 in a direction in which the tape 5 is rewound into each reel, and at the same time, the tape loading motor 25 is driven to return the movement guide to the position in the tape unloading state. When this operation is completed, the tape rewinding operation ends in step 39.

The flow of the tape rewinding operation after the occurrence of the power interruption has been described above. In the present embodiment, unlike the previous embodiment, the risk of tape damage during the tape rewinding operation is reduced by performing the tape slack removing operation without moving the guide system.

FIG. 16 is a plan view showing another embodiment of the magnetic tape device of the present invention. In the present embodiment, a drum rotation speed detector 91 is attached to the drum motor 66, so that a very low-speed rotation of the rotating drum 4 can be detected. The accuracy of the rotation speed detector 91 in the low rotation speed range differs between the first embodiment and this embodiment. For other configurations of the present embodiment,
The description is omitted because it is the same as that of the embodiment.

Next, the flow of the tape rewinding operation of the present embodiment when the power is cut off will be described with reference to FIG.
Note that, as in the previous embodiment, the state illustrated in FIGS. 5 and 6 is assumed as the tape state in the initial operation. Also,
The tape rewinding operation is performed in the initial operation flow of the magnetic tape device described with reference to FIG.

First, in step S41, it is confirmed that the rotation of the rotary drum 4 has stopped. Next, in step S42, driving of the T reel 3 is started. As a result, the tape slack generated due to the power interruption is rewound into the T reel 3. Here, in order to avoid tape damage, it is desirable that the rotation speed of the T3 reel is sufficiently low. Further, the S reel 2 is in a free (rotatable) state.

Next, the routine proceeds to step S43, where it is checked by the drum rotation number detector 91 whether or not the rotation of the drum is equal to or more than a predetermined rotation number. If it is determined that the drum is rotating at a predetermined rotation speed or more, the process proceeds to step S45. Here, if it is determined that the drum has not reached the predetermined rotation speed, the process proceeds to step S44, where the S reel rotation speed
It is checked whether or not the reel 2 is rotating at a predetermined rotation speed or more. Here, if it is determined that the S reel 2 is equal to or more than the predetermined rotation speed, the process proceeds to step S45. If it is determined that the S reel 2 has not reached the predetermined number of revolutions, the tape rewind operation by the T reel 3 is continued.

In steps S42, S43 and S44, only the T reel 3 is driven. T reel 3
The rotation of the rotary drum 4 by receiving the frictional force from the tape 5 by the driving of the drive is a state in which the driving force of the T reel 3 is transmitted to the vicinity of the drum. It is determined that there is no slack. The rotation of the S reel 2 by the driving of the T reel 3 means that the driving force of the T reel 3 has been transmitted to the S reel 2 via the tape.
It is determined that there is no slack. During the slack removal process,
Due to the change in the frictional state between the tape and the rotating drum, it is assumed that the movement of the tape on the rotating drum causes the rotating drum to rotate and does not rotate. If the tape 5 is not rotated, the tape slackening on the S reel side will be wound on the T reel according to the above operation flow, and the tape 5 will move on the rotating drum. The tape-rotating drum interaction described with reference to FIG. 8 does not occur, so that tape damage does not occur.

From the above, it is determined that there is no slack in the tape on the T reel side in the process of proceeding to step S45.
In step S45, the T reel 2 is stopped.

Next, the flow advances to step S46 to start driving the S reel 2. As a result, the tape slack on the side of the S reel 2 generated by the power interruption is rewound into the S reel 2. Here, in order to avoid tape damage, it is desirable that the rotation speed of the S reel 2 is sufficiently low. Also, T
The reel 2 is in a free (rotatable) state.

Then, the process proceeds to a step S47, wherein it is checked whether or not the rotation of the drum is equal to or more than a predetermined rotation speed by the drum rotation speed detector 91. If it is determined that the drum is rotating at a predetermined rotation speed or more, the process proceeds to step S49. Here, if it is determined that the drum does not reach the predetermined rotation speed, the process proceeds to step S48, and the T reel rotation speed detector 24 checks whether the T reel 3 is rotating at a predetermined rotation speed or more.
Here, if it is determined that the T reel 3 is equal to or higher than the predetermined number of revolutions, the process proceeds to step S49. When it is determined that the T reel 3 has not reached the predetermined number of revolutions, the tape rewinding operation by the S reel 2 is continued.

According to the same algorithm as the above-described T-reel slack removing operation, the process proceeds to step S49 in the process of step S49.
It is determined that there is no tape slack on the reel side. Therefore, the S reel 2 is stopped.

Then, the process proceeds to a step S50 to execute a tape unloading operation. The tape unloading operation is the tape unloading operation of the previous embodiment (FIG. 1).
5, step S38), and a description thereof will be omitted. Thus, the tape rewinding operation of the present embodiment is completed.

In the above, the flow of the tape rewinding operation after the power interruption has occurred has been described. In this embodiment, as in the previous embodiment, the risk of tape damage during the tape rewinding operation is reduced by performing the tape slack removal operation without moving the guide system.

[0066]

As described above, according to the present invention,
The tape slack generated by the power interruption can be safely rewound without damaging the tape, and can be returned to the state before the power interruption. Further, since a certain amount of tape slack due to power interruption can be allowed, a mechanical brake or the like can be omitted, and a low-cost and highly reliable magnetic tape device can be supplied.

[Brief description of the drawings]

FIG. 1 is a perspective view of a magnetic tape device.

FIG. 2 is a plan view of the magnetic tape device.

FIG. 3 is a plan view showing the position of a tape guide.

FIG. 4 is a plan view showing the position of a tape guide.

FIG. 5 shows a tape state when the power is turned off.

FIG. 6 shows a tape state when the power is turned off.

FIG. 7 is a configuration of a rotary drum.

FIG. 8: Tape-rotating drum interaction.

FIG. 9 is a configuration of a magnetic tape device.

FIG. 10 is an initial operation flow of the magnetic tape device.

FIG. 11 is a flowchart of a tape rewinding operation.

FIG. 12 is a guide position at the time of winding the tape.

FIG. 13 is a plan view of the magnetic tape device.

FIG. 14 is a side view of a tape guide with a speed detector.

FIG. 15 is a flowchart of a tape rewinding operation.

FIG. 16 is a plan view of a magnetic tape device.

FIG. 17 is a flowchart of a tape rewinding operation.

[Explanation of symbols]

1 ... chassis, 2 ... S reel (supply side reel), 3 ... T
Reel (winding side reel), 4 ... rotary drum, 5 ... tape, 6, 7, 12, 13, 17 ... guide, 8, 11 ...
Movement guide, 9, 10: Movement pin, 14: Rotary switch, 15, 18: Base member, 16: Cassette, 2
1, 23 ... reel motor, 22, 24 ... rotation number detector,
25: Tape loading motor, 26, 29: Moving base, 27, 28: Circular member, 30, 31, 32, 33
... groove, 41 ... upper drum, 42 ... lower drum, 43 ... drum base, 44 ... lead, 45 ... magnetic head, 46 ... shaft, 61 ... controller, 62, 63 ... reel motor driver, 64 ... drum motor driver, 65 ... TL
(Tape loading) Motor driver, 66: drum motor, 67: drum rotation speed detector, 81: tape guide with speed detector, 82: base, 83: shaft, 84
... Roller part, 85 ... Top flange part, 86 ... Connection member, 8
7 ... Encoder disk part, 88 ... Encoder rotation detector,
91: drum rotation number detector.

Claims (3)

[Claims] A plurality of movable drums; a rotation detector provided on at least one of the reel motors for detecting a rotation speed of the reel motor; a rotating drum provided with a magnetic head for performing magnetic recording and reproduction; In a magnetic tape device provided with a tape guide, after a power interruption occurs, the tape guide moves in a direction away from the rotating drum, and during the operation of removing the tape slack generated by the power interruption, the tape winding on the rotating drum is performed. A magnetic tape device wherein an angle is set smaller than a tape transfer state during magnetic recording and reproduction. 2. A power supply cutoff occurs in a magnetic tape device including two reel motors, a rotary drum provided with a magnetic head for performing magnetic recording and reproduction, and a tape speed detector for detecting a tape speed near the rotary drum. Then, during the operation of removing the tape slack generated by the power interruption, the tape speed detector is monitored, and a first slack removal process of driving one of the reels is performed until the tape speed exceeds a predetermined value. After the tape speed exceeds a predetermined value, a second drive for driving the other reel
A magnetic tape device for performing slack removal processing. 3. A rotating drum provided with two reel motors, two rotating speed detectors for detecting respective rotating speeds of the reel motor, a magnetic head for performing magnetic recording and reproduction, and a rotating speed of the rotating drum. In a magnetic tape device provided with a rotation speed detector for detecting a power supply, after a power supply interruption occurs, one of the reel motors is driven during an operation of removing a tape slack generated by the power supply interruption,
The first slack removal process is performed until the rotation speed of the rotating drum exceeds a predetermined value or the rotation speed of the reel motor that is not driven exceeds the predetermined value, and then the drive is performed in the first slack removal process. The second reel motor is driven until the rotation speed of the rotating drum exceeds a predetermined value or the rotation speed of the non-driven reel motor exceeds a predetermined value. A magnetic tape device characterized by the above-mentioned.