Magnetic tape drive

Abstract

This prevents magnetic tape from falling off its path during a power outage. [Solution] The magnetic tape device 10 includes a set of reel mechanisms 20 and 21 that use an electric motor to feed out and wind up the magnetic tape 13, brake mechanisms 30 and 31 configured to apply a brake to the reel mechanism that is feeding out the magnetic tape 13, and a control device 40 that activates the brake mechanism on the reel mechanism that is feeding out the magnetic tape 13 when the power supply to the electric motor is stopped.

Description

[[Technical Field]]

[0001] The present disclosure relates to a magnetic tape device that performs recording and reproduction on magnetic tape. [[Background Art]]

[0002] Conventionally, magnetic tape devices have been known as means for storing large-capacity data. A magnetic tape device is a device that continuously records and reproduces data while feeding magnetic tape at high speed. The magnetic tape device includes a magnetic head that writes and reads data, and a structure in which the magnetic tape is routed while being in contact with the magnetic head and wound around a reel.

[0003] Here, the configuration of a conventional magnetic tape device will be described with reference to Figs. 8 and 9. Fig. 8 is a top view showing the configuration of a conventional magnetic tape device. Fig. 9 is a side view showing the configuration of a conventional magnetic tape device.

[0004] As shown in Figs. 8 and 9, the magnetic tape device 100 is mainly configured of a tape cartridge 101, guide rollers 105, reels, reel motors, a magnetic head 106, and a housing 109. Further, the reels are configured of a cartridge reel 102 and a device reel 104. The reel motors are configured of a motor 107 that drives the cartridge reel 102 and a motor 108 that drives the device reel 104. In Fig. 9, 107A is a shaft of the motor 107, and 107B is a clutch provided on the shaft 107A. 108A is a shaft of the motor 108. Also, in Figs. 8 and 9, only the outer edge of the housing 109 is shown.

[0005] The tape cartridge 101 stores the magnetic tape 103 by attaching one end of the magnetic tape 103 to the cartridge reel 102 and winding it up. When this tape cartridge 101 is inserted into the magnetic tape device 100, the leading end of the magnetic tape 103 wound on the cartridge reel 102 is pulled out from the tape cartridge 101, and the magnetic tape 103 is then routed along a predetermined path and wound onto the device reel 104 inside the magnetic tape device.

[0006] After this state is reached, the magnetic tape 103 becomes capable of moving between the cartridge reel 102 and the device reel 104 within the magnetic tape drive. Regarding the direction of movement of the magnetic tape 103, the direction of movement from the cartridge reel 102 to the device reel 104 is called the forward direction, and this movement is called the forward movement. Also, the direction of movement of the magnetic tape 103 from the device reel 104 to the cartridge reel 102 is called the reverse direction, and this movement is called the reverse movement.

[0007] As described above, the magnetic tape 103 travels along a predetermined path within the magnetic tape drive 100, is guided by the guide roller 105 along that path, and comes into contact with the magnetic head 106 that reads and writes data. By moving the magnetic tape 103 at the same time that the magnetic head 106 reads or writes data, data is continuously recorded or played back. The movement speed of the magnetic tape 103 at that time is kept constant by adjusting the rotation speed of the reel motors to stabilize the recording accuracy.

[0008] The rotation speed of the reel motor is variably controlled according to the amount of magnetic tape 103 wound on the reel. When a large amount of magnetic tape 103 is wound, the diameter is larger, so the rotation speed is slowed down. When a small amount of magnetic tape 103 is wound, the diameter is smaller, so the rotation speed is increased. This control is performed to maintain a constant movement speed of the magnetic tape 103.

[0009] Figures 10 and 11 will be used to explain the forward operation in a conventional magnetic tape drive. Figure 10 is a diagram illustrating the forward operation in a magnetic tape drive. Figure 11 is a diagram showing the change in the amount of tape wound during the forward operation.

[0010] As shown in Figure 10, during forward operation, the magnetic tape 103 moves from the cartridge reel 102 to the device reel 104. In Figure 11, the change in the amount of tape during forward operation is shown in the beginning, middle, and end stages. As shown in Figure 11, at the beginning, almost all of the tape is wound on the cartridge reel 102, and there is almost no tape on the device reel 104. In the middle stage, the cartridge reel 102 and the device reel 104 have roughly the same amount of tape wound on them. In the end stage, most of the magnetic tape 103 has been fed out from the cartridge reel 102 and wound onto the device reel 104.

[0011] Now, suppose a power outage occurs in the magnetic tape drive 100 while the magnetic tape 103 is moving at high speed to read or write data. In this case, if the rotation speeds of the reel motors of the cartridge reel 102 and the device reel 104 are different, there will be a difference in the time it takes for each reel motor to stop. As a result, the magnetic tape 103 will not be wound up properly, will remain on the path, sag under its own weight, and fall off the designated path. Consequently, the magnetic tape 103 that has fallen off the path may come into contact with the surrounding metal frame or uneven parts of the mechanism, potentially causing damage. Furthermore, such damage can lead to breaks, folds, and tears in the magnetic tape, which can result in a decrease in data reproducibility and even data loss.

[0012] To prevent magnetic tape from falling off during such power outages, the magnetic tape device 100 has conventionally used a short-circuit brake. Here, we will explain the short-circuit brake. Normally, even if power is not supplied due to a power outage, the reel motor is kept rotating by the inertia of the reel that was rotating just before, so a back electromotive force is generated in the reel motor. If the coil terminals of the reel motor are short-circuited at this time, the back electromotive force generates a braking force in the reel motor. Stopping the reel in a short time using this braking force is called a "short-circuit brake".

[0013] Furthermore, if this short-circuit brake is generated only on the reel that feeds out the magnetic tape during a power outage, the brake will only be applied to the feeding reel, and not to the taking-up reel. As a result, the taking-up reel will continue to rotate by inertia. Consequently, the amount of magnetic tape fed out from the reel stopped by the short-circuit brake will be less than the amount of magnetic tape being taken up. In this case, tension will continue to be applied to the magnetic tape, and the magnetic tape will remain stationary along its predetermined path.

[0014] Furthermore, Patent Document 1 discloses a braking mechanism for a magnetic tape device that mechanically applies a brake to the reels. The braking mechanism disclosed in Patent Document 1 prevents the magnetic tape from falling off the path by simultaneously applying brakes to both reels during a power outage. [Prior art documents] [Patent Documents]

[0015] [Patent Document 1] Japanese Patent Application Publication No. 05-266541 [Overview of the project] [Problems that the invention aims to solve]

[0016] However, with short brakes and the brake mechanism disclosed in Patent Document 1, it is difficult to reliably prevent the magnetic tape from falling off the path during a power outage. This will be explained below.

[0017] First, let's assume a power outage occurs when most of the magnetic tape is on the feed-side reel. In this case, because the reel's rotation speed is slow, the back electromotive force is small, and the braking force of the short-circuit brake is small. Conversely, because most of the magnetic tape remains, the feed-side reel is heavy and difficult to stop. Therefore, the time required for the feed-side reel to stop increases, and the take-up reel, which was rotating by inertia, stops first, making it impossible to wind up the magnetic tape. As a result, with a short-circuit brake, the magnetic tape is fed out excessively, sags, and ultimately falls off the track.

[0018] Furthermore, the braking mechanism disclosed in Patent Document 1 has a structure in which the same force is applied to both reels simultaneously. Therefore, if a power outage occurs when most of the magnetic tape is on the feed-out reel, the reel taking up the tape will stop before the feed-out reel, even with the braking mechanism disclosed in Patent Document 1. As a result, similar to the case of a short-circuit brake, the magnetic tape is fed out excessively, sags, and consequently falls off the path.

[0019] One example of the purpose of this disclosure is to prevent magnetic tape from falling off its path during a power outage. [Means for solving the problem]

[0020] To achieve the above objective, a magnetic tape device in one aspect of this disclosure is A set of reel mechanisms, which use an electric motor to feed and rewind magnetic tape, A brake mechanism is configured to apply a brake to the reel mechanism that is feeding out the magnetic tape, a control device that, when power supply to the electric motor is stopped, activates the brake mechanism for the one of the reel mechanisms that is feeding out the magnetic tape; , characterized by comprising: [Effects of the Invention]

[0021] As described above, according to the present disclosure, falling of the magnetic tape from its path when a power outage occurs can be suppressed. [Brief Description of the Drawings]

[0022] [Figure 1] FIG. 1 is a configuration diagram showing a schematic configuration of an example of a magnetic tape drive. [Figure 2] FIG. 2 is a configuration diagram specifically showing the brake mechanism for the magnetic tape illustrated in FIG. 1. [Figure 3] FIG. 3 is a configuration diagram showing the configuration of the magnetic tape drive illustrated in FIG. 1 from a side view. [Figure 4] FIG. 4 is a configuration diagram showing a state in which the brake mechanism illustrated in FIG. 2 is activated. [Figure 5] FIG. 5 is a diagram showing an example of a timing chart in a magnetic tape drive provided with a brake mechanism. [Figure 6] FIG. 6 is a diagram showing an example of a timing chart in a conventional magnetic tape drive not provided with a brake mechanism. [Figure 7] FIG. 7 is a diagram showing an example of the operation of each part depending on the state of the magnetic tape drive. [Figure 8] FIG. 8 is a top view showing the configuration of a conventional magnetic tape drive. [Figure 9] FIG. 9 is a side view showing the configuration of a conventional magnetic tape drive. [Figure 10] FIG. 10 is a diagram explaining a forward operation in a magnetic tape drive. [Figure 11] FIG. 11 is a diagram showing a change in the amount of tape wound during a forward operation. [Modes for carrying out the invention]

[0023] (Embodiment) In the following description, an example of a magnetic tape device will be explained with reference to Figures 1 to 7.

[0024] First, we will explain the schematic configuration of an example of a magnetic tape drive using Figure 1. Figure 1 is a schematic diagram showing the schematic configuration of an example of a magnetic tape drive.

[0025] As shown in Figure 1, the magnetic tape device 10 is a device that records and plays data on a magnetic tape 13 housed in a tape cartridge 11 using a magnetic head 16. As shown in Figure 1, the magnetic tape 10 includes a set of reel mechanisms 20 and 21, brake mechanisms 30 and 31, and a control device 40.

[0026] Reel mechanisms 20 and 21 each use an electric motor to feed out and rewind the magnetic tape 13. Brake mechanisms 30 and 31 are provided for each reel mechanism and are configured to apply a brake to the reel mechanism that is feeding out the magnetic tape 13.

[0027] The control device 40 activates a corresponding brake mechanism on one of the reel mechanisms that is feeding out the magnetic tape 13 when the power supply to the electric motors provided in each of the reel mechanisms 20 and 21 is stopped.

[0028] In Figure 1, 12 is a cartridge reel driven by the reel mechanism 20. The cartridge reel 12 is provided on the tape cartridge 11. Furthermore, 14 is a device reel driven by the reel mechanism 21. 19 is a housing, only its outer edge is shown in Figure 1. 15 is a guide roller for guiding the magnetic tape 13 along the path.

[0029] Thus, in the magnetic tape device 10, when a power outage occurs, a brake is applied only to the reel mechanism that feeds out the magnetic tape. Therefore, unlike when only a short brake is equipped, or when the brake mechanism disclosed in Patent Document 1 is equipped, the situation in which the magnetic tape falls off the path without being wound up is avoided.

[0030] Next, the configuration of the magnetic tape device 10 will be specifically explained using Figures 2 to 4. Figure 2 is a configuration diagram specifically showing the magnetic tape braking mechanism shown in Figure 1. Figure 3 is a configuration diagram showing the configuration of the magnetic tape device shown in Figure 1 from the side. Figure 4 is a configuration diagram showing the state in which the braking mechanism shown in Figure 2 is activated. In Figures 2 to 4, the housing 19 is shown only by its outer edge.

[0031] As shown in Figures 2 and 3, the brake mechanism 30 is provided on the reel mechanism 20, and the brake mechanism 31 is provided on the reel mechanism 21. The reel mechanism 20 also includes an electric motor 17 for rotating the cartridge reel 12. The cartridge reel 12 is connected to the shaft 17a of the electric motor 17 via a clutch 17b. The reel mechanism 21 includes an electric motor 18 for rotating the device reel 14. The device reel 14 is connected to the shaft 18a of the electric motor 18.

[0032] Furthermore, the brake mechanism 30 is composed of a brake member 30a, a solenoid 30b, a coil spring 30c, a lever shaft 30d, and a fastener 30e. Similarly, the brake mechanism 31 is composed of a brake member 31a, a solenoid 31b, a coil spring 31c, a lever shaft 31d, and a fastener 31e.

[0033] The brake member 30a is positioned so as to be switchable between contact and non-contact with the cartridge reel 12 that constitutes the reel mechanism 20. Specifically, the brake member 30a has a shape that is elongated in one direction, and one end of it is rotatably held by a lever shaft 30d. The lever shaft 30d is parallel to the shaft 17a, and is positioned so that the brake member 30a can rotate around the lever shaft 30d to contact the shaft 17a. The lever shaft 30d is fixed to the housing 19.

[0034] The solenoid 31b is positioned at the other end of the brake member 30a so as to enable switching between contact and non-contact between the brake member 30a and the shaft 17a. Specifically, as shown in Figure 2, the solenoid 31b is positioned so that when its plunger is operated, the brake member 30a rotates around the lever shaft 30d.

[0035] Furthermore, a coil spring 30c is positioned at one end of the brake member 30a to restrict the rotation of the brake member 30a. Specifically, one end of the coil spring 30c is fixed to the brake member 30a, and the other end is fixed to a fastener 30e. The fastener 30e is fixed to the housing 19.

[0036] With this configuration, as shown in Figure 2, when power is supplied to the solenoid 31b in the brake mechanism 30, the plunger of the solenoid 31b protrudes, and the brake member 30a becomes non-contact with the electric motor 17 (shaft 17a).

[0037] On the other hand, as shown in Figure 4, when the power supply to the solenoid 31b is stopped, the plunger of the solenoid 31b retracts, and the brake member 30a comes into contact with the electric motor 17 (shaft 17a) and is further pressed against it by the restoring force of the coil spring 30c, thereby applying the brake to the electric motor 17.

[0038] In the brake mechanism 31, the brake member 31a, solenoid 31b, coil spring 31c, lever shaft 31d, and fastener 31e are configured and function in the same way as in the brake mechanism 30.

[0039] The control device 40 activates the brake mechanism 30 by controlling the solenoid 30b, and activates the brake mechanism 31 by controlling the solenoid 31b. Furthermore, in the event of a normal power outage, the control device 40 activates the conventional short brake, and in the event of a specific power outage, it can activate either the brake mechanism 30 or the brake mechanism 31 in addition to the short brake.

[0040] Here, a specific power outage occurs when the amount of magnetic tape wound up is small, the short-circuit brake is weak, and the magnetic tape 13 falls off the path. In other words, a specific power outage occurs when the amount of magnetic tape wound up in one reel mechanism satisfies the set conditions, and the power supply to the motor is stopped. The set conditions are determined in advance by experimentation to identify the amount of magnetic tape 13 wound up at which the magnetic tape 13 falls off the path with only the short-circuit brake.

[0041] Furthermore, the control device 40 determines whether the above setting conditions are met, for example, by the elapsed time since the start of forward or reverse operation in the magnetic tape device 10. Therefore, if the time from the start of forward or reverse operation until the occurrence of a power outage is less than or equal to the threshold corresponding to the above setting conditions, the control device 40 determines that the above setting conditions are met and activates the brake mechanism.

[0042] Next, the operation of the control device in the magnetic tape device 10 will be specifically explained using Figures 5 and 6. Figure 5 is a diagram showing an example of a timing chart in a magnetic tape device equipped with a braking mechanism. Figure 6 is a diagram showing an example of a timing chart in a conventional magnetic tape device without a braking mechanism.

[0043] Figures 5 to 7 show the forward movement of the magnetic tape from the cartridge reel 12 to the device reel 14. The power outage detection signal shown in Figures 5 to 7 is a signal input to the control device 40. When the power supply voltage drops, it is activated by the electrical circuit built into the magnetic tape device 10, and when the power supply voltage is normal, it is in standby mode. In other words, the power outage detection signal is automatically set to active or standby mode by the electrical circuit according to the power supply voltage.

[0044] In Figures 5 and 7, the mechanical brake signal is a signal used by the control device 40 to control the brake mechanisms 30 and 31. The control device 40 sets the mechanical brake signal of the reel that is on the feeding side of the cartridge reel 12 and the device reel 14 to active, and the mechanical brake signal of the reel that is on the winding side to standby, according to the operating status (forward operation or reverse operation).

[0045] As shown in Figures 5 and 7, since it is in forward operation, the control device 40 activates the mechanical brake signal of the cartridge reel 12, which is the tape feed reel. Also, in the example in Figure 5, a power outage occurs when the magnetic tape 13 is almost completely remaining on the feed-side cartridge reel 12 (satisfying the above setting conditions). For this reason, the control device 40 abruptly stops the power supply to the solenoid 30b and activates the brake mechanism 30. On the tape take-up side, the power supplied to the solenoid 31b gradually decreases due to the power outage, and becomes zero when the power is lost.

[0046] On the other hand, during reverse operation, the control device 40 activates the mechanical brake signal of the device reel 14. Then, if a power outage occurs while the magnetic tape 13 is almost completely remaining on the device reel on the feed side, the control device 40, conversely to the above, abruptly stops the power supply to the solenoid 31b and activates the brake mechanism 31.

[0047] Furthermore, as shown in Figure 6, if the brake mechanisms 30 and 31 are not provided, only short braking will be available. In this case, a discrepancy will occur between the timing at which the take-up reel stops and the timing at which the feed-side reel stops. Such a discrepancy may cause the magnetic tape 13 to fall off the path.

[0048] Furthermore, we consider situations where the tape cartridge 11 is not housed in the magnetic tape device 10, and situations where the tape cartridge 11 is housed in the magnetic tape device 10, but the magnetic tape 13 is not moving. In these situations, the control device 40 sets the mechanical brake signals of each reel to active.

[0049] In this situation, when a power outage occurs and the power outage detection signal becomes active, the control device 40 stops the power supply to each solenoid and activates each braking mechanism, since each mechanical brake signal is active. As a result, even if the tape cartridge 11 is inside the magnetic tape device 10, each reel is held in the stopped state it was in before the power outage by each braking mechanism, so the magnetic tape 13 does not loosen.

[0050] Furthermore, in the above-described situation, when forward or reverse operation is initiated, the mechanical brake signal of the winding reel is set to standby.

[0051] Here, we will explain the operation of each part of the magnetic tape device 10 under different conditions using Figure 7. Figure 7 is a diagram showing an example of the operation of each part of the magnetic tape device under different conditions.

[0052] As shown in Figure 7, when the power outage detection signal is active and the mechanical brake signal is active, the control device 40 stops the power supply to the solenoid on the feed side and activates the brake mechanism when the above setting conditions are met.

[0053] Furthermore, even if the power outage detection signal is active, the control device 40 continues to energize the solenoid and keep the brake mechanism released if the mechanical brake signal is in standby mode. In this case, if the power drops and the solenoid becomes unable to operate, the brake mechanism will be activated by the spring.

[0054] Furthermore, as shown in Figure 7, when power is supplied normally to the magnetic tape device 10, the power failure detection signal is in standby mode. In this case, regardless of the state of the mechanical brake signal, the control device 40 continuously energizes each solenoid and releases the brake mechanism. In this state, the movement of each motor is not hindered, and the forward and reverse movements that move the magnetic tape 13 can be performed freely.

[0055] Next, using Figure 7, we will explain what happens when a power outage occurs during forward operation. First, when the tape cartridge 11 is housed in the magnetic tape device 10 and forward operation is being performed, the mechanical brake signal of the feed-side reel is active, and the mechanical brake signal of the take-up-side reel is in standby mode. If a power outage occurs at this time, the power outage detection signal becomes active.

[0056] First, the control device 40 applies a short brake to the cartridge reel 12, which is the feed-side reel, as in the conventional configuration. Furthermore, since the power outage detection signal is active and the mechanical brake signal of the cartridge reel 12 is active, the control device 40 stops the power supply to the solenoid 30b and activates the brake mechanism 30. By simultaneously applying this short brake and the brake mechanism 30, the cartridge reel 12 stops in a shorter time than in the conventional configuration.

[0057] Furthermore, the device reel 14, which is the winding reel, rotates by inertia, just as in the conventional configuration. Therefore, although the power failure detection signal is active, the mechanical brake signal for the device reel 14 is in standby mode, so the solenoid 31b remains energized and the brake mechanism 31 remains in the released state. Consequently, the device reel 14 does not have its rotation by inertia hindered and stops in the same amount of time as in the conventional configuration.

[0058] Therefore, the magnetic tape 13 is stopped by the feed reel, which has a short stop time, and the take-up reel is stopped by being pulled by the magnetic tape 13, so that both reels stop with the magnetic tape maintaining tension. As a result, the magnetic tape 13 does not loosen and is maintained in the path. When the power is finally lost, the solenoid on the device reel 14 is de-energized, and a mechanical brake is applied by the spring.

[0059] Furthermore, if a power outage occurs during reverse operation, the operation will be the opposite of the case described above. In this case as well, both reels will stop with the magnetic tape maintaining tension and will remain in the path.

[0060] [Effects in the embodiment] As described above, the magnetic tape device 10 can apply a mechanical brake in addition to the short-circuit brake only to the reel mechanism that is feeding out the magnetic tape. Therefore, even if a power outage occurs during forward operation when most of the magnetic tape remains on the cartridge reel 12, it is possible to prevent the magnetic tape from falling off the path. [Industrial applicability]

[0061] As described above, this disclosure makes it possible to suppress the magnetic tape from falling off the path during a power outage. [Explanation of Symbols]

[0062] 10 Magnetic tape drive 11 Tape Cartridges 12 cartridge reels 13 Magnetic Tape 14. Device Reel 15 Guide rollers 16 Magnetic Heads 17 Electric motor 17a shaft 17b Clutch 18 Electric motor 18a shaft 19 cabinets 20 Reel mechanism 21 Reel mechanism 30 Brake mechanism 30a Brake member 30b Solenoid 30c Coil Spring 30d lever axis 30e fastener 31 Brake mechanism 40 Control device

Claims

1. A set of reel mechanisms, which use an electric motor to feed and rewind magnetic tape, A brake mechanism is configured to apply a brake to the reel mechanism that is feeding out the magnetic tape, A control device that activates the brake mechanism on one of the reel mechanisms that is feeding out the magnetic tape when the power supply to the electric motor is stopped, A magnetic tape device characterized by having the following features.

2. The control device activates the brake mechanism on the other reel mechanism that is feeding out the magnetic tape when the amount of magnetic tape wound up in one of the reel mechanisms satisfies a set condition and the power supply to the electric motor is stopped. The magnetic tape device according to claim 1.

3. The aforementioned brake mechanism is provided for each of the sets of the aforementioned reel mechanisms. A brake member is positioned so as to be able to switch between contact and non-contact with the reel constituting the reel mechanism, A solenoid is provided to keep the brake member non-contact with the electric motor when power is being supplied to the electric motor. It is equipped with The magnetic tape device according to claim 1.

4. The control device operates the brake mechanism by controlling the solenoid. The magnetic tape device according to claim 3.

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