JP3645859B2 - Cartridge type magnetic tape unit - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a magnetic tape device, and more particularly to a cartridge type magnetic tape device for winding a magnetic tape of a magnetic tape cartridge.
[0002]
[Prior art]
FIG. 8 is a perspective view showing a magnetic tape cartridge (hereinafter simply referred to as a cartridge) 2 mounted on this type of cartridge type magnetic tape device, and FIG. 9 shows the cartridge 2 shown in FIG. The top view seen from the inside is shown.
[0003]
As shown in FIG. 9, the magnetic tape 5 is wound around the cartridge tape reel 6 and is housed in the cartridge 2 in a state where the leading end leader pin is locked to the corner of the cartridge. Is normally housed in a state in which the end is linearly stretched on a tangent line connecting the outer circumference of the end of winding of the magnetic tape 5 and the leader pin 10. A clutch 9 connected to a file reel motor, which will be described later with reference to FIG. 2, is accommodated coaxially on the inner periphery of the cartridge tape reel 6.
[0004]
On the other hand, FIG. 10 shows the cartridge 2 in a state in which the end of the magnetic tape 5 is loosened. In the cartridge type magnetic tape apparatus to which the cartridge 2 containing the magnetic tape 5 in such a state is supplied, When reading / writing of data is started from this state (hereinafter referred to as a thread), not only is there a possibility that the leader pin 10 may fall off due to a sudden tension applied to the magnetic tape 5, but in the unlikely event that the inside of the wound portion is Even if it is cut, it cannot be visually determined.
[0005]
Therefore, in such a case, the magnetic tape 5 is wound in advance before starting the thread, and in this case, it will be described later with reference to FIG. 2 connected to the lower part through the clutch 9 inside the cartridge tape reel 6. The file motor is driven to rotate the cartridge tape reel 6 in the counterclockwise direction indicated by the arrow B in FIG.
[0006]
FIGS. 11A and 11B show time charts of the winding operation of the conventional cartridge type magnetic tape apparatus. As shown in this time chart, in the conventional cartridge type magnetic tape apparatus, when the magnetic tape is slack, a control voltage of DC 5.2V is applied to the file reel motor during the acceleration time 44, and the magnetic tape is It is tightened.
[0007]
[Problems to be solved by the invention]
However, since the acceleration time 44 of the file reel motor is proportional to the slack length of the magnetic tape, when this length is longer than the normal length, the winding start 45 shown in FIG. The time required from the completion of the tightening to the tightening 46 becomes longer, and the rotational speed of the cartridge tape reel increases accordingly. Then, when the winding is completed 46, an excessive tension is generated on the magnetic tape as the cartridge tape reel suddenly stops.
[0008]
FIG. 11C shows detection information of the rotation angle of the file reel motor by a hall sensor attached to the file reel motor. After a predetermined time has elapsed after the state change 47 of the last hall sensor, the file reel motor The file reel motor is stopped by returning the control voltage to 5V. Therefore, the file reel motor cannot be stopped when the winding is completed.
[0009]
In addition, the file reel motor continues to accelerate from the start of tightening 45 to the end of tightening 46, and the tension of the magnetic tape at the end of tightening 46 is excessive due to the inertia of the file reel motor, the magnetic tape, and the tape reel. It becomes.
[0010]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a cartridge type magnetic tape device that can reduce an impact caused by excessive tension applied to a magnetic tape when a magnetic tape stored in a slack state is tightened. .
[0011]
[Means for Solving the Problems]
In order to solve this problem, the present invention has a reel motor for winding a magnetic tape of a cartridge and a detector for detecting the rotation angle of the reel motor, and reduces the resolution of one state of the detector. The reel motor is driven by a plurality of divided control pulses, and the control pulses are stored in a nonvolatile area of the magnetic tape .
[0012]
The reel motor is a three-phase 8-pole, 10-pole or 12-pole brushless motor, and the detector is a hall sensor attached to the three-phase brushless motor, and the resolution of the detector is three-phase brushless. It is preferably 15 degrees, 12 degrees, or 10 degrees corresponding to the number of poles, and the control pulse is preferably stored in a nonvolatile area of the magnetic tape.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a cartridge type magnetic tape apparatus of the present invention will be described in detail with reference to the drawings.
[0014]
FIG. 1 shows a cartridge type magnetic tape device 1 according to the present invention, and is a perspective view showing that a cartridge is mounted. FIG. 2 (a) is a plan view after the cartridge 2 is mounted, and FIG. FIG.
[0015]
In this cartridge type magnetic tape apparatus 1, the leader pin 10 at the tip of the magnetic tape 5 is pulled out after the cartridge 2 is mounted as shown in the enlarged plan view of FIG. 3 to the machine reel 3 through four idler reels 4. Further, the data is read and written, that is, the above-described threading is performed by engaging with the locking pin of the machine reel. FIG. 3 shows the cartridge type magnetic tape apparatus 1 in which the magnetic tape 5 is threaded from the cartridge tape reel 6 to the machine reel 3.
[0016]
In the cartridge type magnetic tape apparatus 1, the speed of the file reel motor 7 and the machine reel motor 8 for driving the cartridge tape reel 6 and the machine reel 3 is controlled by a control board (not shown) incorporated in the cartridge type magnetic tape apparatus 1. Thus, the target current value is controlled via the control voltage applied to each reel motor.
[0017]
Further, the control board is provided with a constant current driver circuit (torque control) for controlling the tension of the magnetic tape by the filing motor 7 and the machine rail motor 8, and further, the tension (torque) of the magnetic tape. In addition to the above control, a speed detecting means for controlling the speed is added to detect a difference from the target speed, and an acceleration torque and a deceleration torque are determined based on this difference to perform feedback control.
[0018]
These reel motors are three-phase eight-pole brushless DC motors having a PWM (pulse width modulation) control function, and control of a target current value for accelerating and decelerating the reel motors with voltage. Do by level.
[0019]
These reel motors are stopped when DC 5 V is applied to the speed control input, and are rotated in the forward direction when a voltage exceeding 5 V is applied, and are reversed when a voltage less than 5 V is applied.
[0020]
Further, these reel motors are not provided with a tacho encoder generally used for detecting the rotational position, and correspond to a three-phase 8-pole brushless DC motor, 24 times in one round, that is, 360 °. A hall sensor that changes at a pitch of 15 ° of 1/24 is provided, and only this hall sensor serves as a speed detection means (position detection means) of the reel motor.
[0021]
Further, in the cartridge type magnetic tape apparatus 1 of the present invention, a motor control pulse for 3 ° movement (hereinafter simply referred to as a control pulse) that divides one hall sensor for one state (ie, 15 °) into 5 parts is used. To drive the reel motor.
[0022]
That is, in the cartridge type magnetic tape apparatus 1 of the present invention, a control pulse (voltage level and pulse width) for dividing 15 ° into five is measured in advance in a reel motor that generates position information in 15 ° increments via a hall sensor. By driving the reel motor with this control pulse, each reel motor is apparently controlled with an accuracy five times that of the detector.
[0023]
Therefore, as shown in the motor control time chart shown in FIG. 4A, the reel motor can be driven intermittently in increments of 3 °, and the tightening operation can be performed with intermittent acceleration time. Therefore, the speed of the reel motor can be suppressed, excessive tension generated at the completion of winding of the magnetic tape can be prevented, and stress associated therewith can be reduced.
[0024]
The determination of the completion of the winding of the magnetic tape is performed by rotating the reel motor with a control pulse in increments of 3 °, and starting from the state change 43 of the last Hall sensor shown in FIG. It is assumed that a 15 ° change in the Hall sensor cannot be detected in a continuous pulse.
[0025]
FIG. 5 shows a flowchart of control pulse determination at the time of starting the file reel motor. As shown in this flowchart, in the cartridge type magnetic tape device 1, when the cartridge is inserted (step 12), when the magnetic tape is slackened, the magnetic tape device 1 prevents the leader pin 10 from falling off when sled. Regardless of how loose the tape is, tighten it first.
[0026]
At that time, the above-mentioned default control pulse measured at the time of shipping inspection at the manufacturing factory of the file reel motor is used (step 13), and first, 10 pulses in the clockwise direction indicated by the arrow C in FIG. Drive to bend the magnetic tape (step 14). At this time, the hall sensor is monitored to determine whether or not the file reel motor has just rotated by two states (30 °) (step 15).
[0027]
If rotated by 30 °, the used control pulse is overwritten in the non-volatile area of the magnetic tape (step 16), and a counterclockwise tightening operation indicated by arrow D in FIG. 17) End (step 18).
[0028]
On the contrary, if it is less than 30 °, it is judged whether or not the rotation angle of the file reel motor is 30 ° or more (step 19). The control pulse is tightened for 10 pulses (that is, the loose length).
[0029]
The operation of step 20 is a tightening operation because the magnetic tape cannot be continuously loosened inside the cartridge when the adjustment of the control pulse of the file reel motor is repeated many times.
[0030]
Next, the control voltage is adjusted to decrease the rotation angle of the file reel motor or the pulse width is decreased to adjust the control pulse (step 21), and the process returns to step 15 to again rotate the rotation angle of the file reel motor. It is determined whether or not the angle has reached 30 ° (step 19).
[0031]
If the file reel motor is rotated by 30 ° or more, the control pulse used when the file reel motor is loosened is used to tighten 10 pulses (the loose length) again (step 22). Next, the control voltage is increased or the pulse width is increased, the control pulse is adjusted in the direction of increasing the rotation angle (step 23), the process returns to step 15 again, and this is repeated thereafter.
[0032]
FIG. 6 shows a flowchart of the winding operation of the magnetic tape. As shown in this flowchart, when a cartridge is inserted into the cartridge type magnetic tape device (step 31), first, the control pulse stored in the non-volatile area of the magnetic tape device is loaded into the speed control unit of the control board (step 32). Then, the magnetic tape is wound by 5 pulses with this control pulse (step 33), and it is determined whether the Hall sensor has not changed during the past 5 pulses (step 34).
[0033]
When the Hall sensor has not changed, the tightening is completed (Step 35) and the process ends (Step 36). Conversely, when the Hall sensor has changed during the past five pulses, 1 is further added. The pulse is tightened (step 37), the process returns to step 34, and it is determined again whether or not the hall sensor has changed during the past five pulses, and this is repeated until the hall sensor no longer changes.
[0034]
Thus, by preliminarily storing the control pulse for rotating the file reel motor by 3 ° in the non-volatile area of the magnetic tape, the winding operation can be performed while adjusting the acceleration of the file reel motor. Excessive tension applied to the tape at the completion of winding can be reduced.
[0035]
In the above-described embodiment, the tightening operation when the magnetic tape is loosened when the cartridge is mounted has been described. However, the tightening operation of the present invention is also applied when the operation of loosening the magnetic tape is required. Can do.
[0036]
That is, in the cartridge type magnetic tape device, when the cartridge 2 is mounted, the cartridge tape reel of the cartridge 2 and the file reel motor 7 are connected by the clutch 9 (hereinafter referred to as a mount).
[0037]
A clutch 11 on the file reel motor side connected to the clutch 9 is shown in FIG. The clutch 11 is the same product as the cartridge-side clutch 9, and the rotation of the file reel motor is transmitted to the cartridge tape reel 6 by engaging the crests and troughs of both teeth.
[0038]
Here, when these clutches are engaged, the centers of these clutches may be misaligned and the teeth of both may not be engaged. At this time, the clutches 9 and 11 are engaged even if the mount is retried. There is no time. In this case, conventionally, the file reel motor 7 is driven with a predetermined torque in the direction in which the magnetic tape is loosened to forcibly engage these clutches (hereinafter referred to as a kick operation). By operation, the magnetic tape of the cartridge becomes looser than usual.
[0039]
Therefore, even when the magnetic tape is loosened along with this kicking operation, the stress due to excessive tension applied to the magnetic tape can be reduced by applying the above-described winding tightening means of the present invention.
[0040]
Furthermore, the impact when winding the magnetic tape can be reduced. That is, when winding a magnetic tape around the cartridge tape reel 6, normally, the impact on the magnetic tape is reduced by reducing the rotational speed of the file reel motor in advance immediately before the winding is completed. The removal completion position can be easily calculated because the rotation angle of the machine reel 4 is counted by the hall sensor after completion of the threading of the magnetic tape and stored in the non-volatile area of the magnetic tape 5.
[0041]
If the stored rotation angle information cannot be used due to unexpected power interruptions, the remaining amount of magnetic tape is calculated from the winding radius of this magnetic tape, and normal winding is performed until just before the winding is completed. And the control pulse is applied by the means of the present invention before the winding is completed to reduce the number of revolutions of the reel motor and reduce the stress applied to the magnetic tape.
[0042]
In the conventional cartridge type magnetic tape device, the magnetic tape may break or come off from the leader pin even when tightening the loose tape, especially after the kicking operation. According to this, such a situation can be avoided.
[0043]
In the above embodiment, the three-phase reel motor has eight poles and the hall sensor has a corresponding resolution of 15 °. However, the reel motor has ten poles. The resolution of the Hall sensor may be set to 12 °, and further, the resolution of the Hall sensor may be increased to 10 ° by setting the number of poles of the reel motor to 12.
[0044]
In addition, the number of divisions of the control pulse to be rotated by these resolutions has been described as 5. However, in consideration of the inertia of the reel motor and the like, in one experimental example of the inventor, 2 to 4 divisions are preferable. The selection is preferably made according to the number of poles of the reel motor employed in the cartridge type magnetic tape apparatus and the inertia including the reel motor, the tape reel, and the magnetic tape.
[0045]
【The invention's effect】
As described above in detail, according to the present invention, by intermittently driving the reel motor and winding the magnetic tape, the impact caused by excessive tension applied to the magnetic tape when the magnetic tape is tightened is applied. Can be reduced .
[Brief description of the drawings]
FIG. 1 is a perspective view showing a cartridge-type magnetic tape device according to an embodiment of the present invention while a cartridge is being mounted.
2A and 2B show an embodiment of a cartridge type magnetic tape device of the present invention, in which FIG. 2A is a plan view and FIG. 2B is a cross-sectional view taken along line AA of FIG.
FIG. 3 is a plan view showing an embodiment of the cartridge type magnetic tape device of the present invention and showing a state in which a magnetic tape is threaded on a machine reel.
FIG. 4 is a time chart showing the operation of an embodiment of the cartridge type magnetic tape apparatus of the present invention, where (a) is the reel motor control voltage, (b) is the tape reel speed, and (c) is the tape reel speed. The detection information of the hall sensor which detects the rotation angle of a reel motor is shown.
FIG. 5 is a flowchart showing the operation of an embodiment of the cartridge type magnetic tape device of the present invention, and shows a flow for determining a reel motor control pulse.
FIG. 6 is a flowchart showing the operation of the embodiment of the cartridge type magnetic tape apparatus of the present invention, and shows the flow of the winding operation of the cartridge tape.
FIG. 7 is a partial perspective view showing another embodiment of the cartridge type magnetic tape device of the present invention.
FIG. 8 is a perspective view showing a cartridge mounted on the present invention and a conventional cartridge type magnetic tape device.
9 is a plan view of the cartridge shown in FIG. 8 viewed from the inside of the upper cover.
10 is a plan view showing an example of a state in which the magnetic tape of the cartridge shown in FIG. 9 has slackened.
FIGS. 11A and 11B are time charts showing the operation of a conventional cartridge type magnetic tape device, where FIG. 11A shows the reel motor control voltage, FIG. 11B shows the tape reel speed, and FIG. 11C shows the reel motor rotation angle. The detection information of the hall sensor to detect is shown.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Cartridge type magnetic tape apparatus 2 Magnetic tape cartridge 3 Machine reel 4 Idler reel 5 Magnetic tape 6 Cartridge tape reel 7 File reel motor 8 Machine reel motor 9 Clutch 10 Leader pin 11 File reel motor clutch

Claims (5)

A reel motor for winding the magnetic tape of the cartridge; and a detector for detecting a rotation angle of the reel motor, and the reel motor is controlled by a control pulse obtained by dividing one state of resolution of the detector into a plurality of states. A cartridge-type magnetic tape device that is driven and stores the control pulse in a non-volatile area of the magnetic tape. 2. The cartridge type magnetic tape device according to claim 1, wherein the magnetic tape is wound up by intermittently driving the reel motor . The reel motor is a brushless motor of three-phase 8-pole or 10-pole or 12-pole, said detector to claim 1 or 2, characterized in that said a Hall sensor that is attached to a three-phase brushless motor The cartridge type magnetic tape device described. The cartridge type magnetic tape device according to claim 1 or 2 , wherein the resolution of the detector is 15 degrees, 12 degrees, or 10 degrees corresponding to the number of poles of a three-phase brushless motor. The reel motor is driven by the control pulse stored in the non-volatile area, the rotation angle of the reel motor at that time is detected by the detector, and the voltage or pulse width of the control pulse is changed according to the rotation angle. 5. The cartridge type magnetic tape device according to claim 4 , wherein the non-volatile area is overwritten .

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