JPS6115509B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in flexible magnetic disk devices, and in particular to improvements in the misalignment of a magnetic head to a prescribed track on a flexible magnetic recording medium caused by a difference in the installation direction of the flexible magnetic disk device. It provides a means to do so.

For convenience of explanation, a recently released double-sided flexible magnetic disk device will be described below as an example.

In double-sided flexible magnetic disk devices, a mini-angle type step is used as a means of driving the carriage on which the magnetic head is mounted, in order to shorten the time required to position the magnetic head on a specified track and to save power for the drive motor. A motor is used and the driving method is to fix a pulley on the output shaft of the step motor, wrap a thin metal band between this pulley and the auxiliary pulley, and then
Many methods are used to convert the intermittent rotational movement of the step motor into reciprocating linear movement of the carriage by fixing the carriage to the motor.

This method has the disadvantage that the position of the magnetic head shifts when the installation orientation of the flexible magnetic disk device is changed. The reason for this is that the load applied to the step motor is different when the mass of the carriage is applied perpendicular to the axial direction of the carriage guide rod, and when the mass is applied parallel to the axial direction of the carriage guide rod. This is because there will be a difference in torque.

To explain in more detail, the load torque (T ₁ ) of the step motor when the carriage mass is applied perpendicularly to the axial direction of the guide rod of the carriage is T ₁ =DμM/2. Here, μ is the coefficient of friction between the carriage and the guide rod, M is the uniform weight of the carriage, and D is the diameter of the pulley on the step motor shaft. On the other hand, when the mass of the carriage is applied parallel to the axial direction of the guide rod of the carriage, the load torque (T ₂ ) of the step motor is T ₂ =D(M-μM)/2, and in this case μ is clearly 1 Since T ₂ > T ₁ , the load torque applied to the step motor is greater when the mass of the carriage is applied parallel to the axial direction of the guide rod of the carriage. Therefore, in this case, the equipment installation position in which the mass of the carriage is parallel to the axial direction of the carriage guide rod applies a greater load than the equipment installation position in which the carriage mass is applied perpendicular to the axial direction of the carriage guide rod. The magnetic head will be shifted to the side by a large amount. The magnitude of this deviation is generally related to the O-T characteristics of the step motor itself, but in the case of step motors used in double-sided flexible magnetic disk devices, the actual deviation is several microns, in some cases several tens of microns. Become. Nao O
-T characteristics expresses the static torque characteristics of a motor.The vertical axis represents the generated torque, and the horizontal axis represents the angle when the rotor and stator of the step motor are shifted.The vertical axis represents the motor's restraint torque. It represents size. Generally speaking, ways to solve such problems include reducing the total mass of the carriage or increasing the motor restraint force, but in reality, the former requires considerable difficulty due to structural limitations. The latter case is quite difficult to realize due to power consumption, space factor, and temperature compensation due to heat generation becomes difficult.

The present invention provides a means to extremely simply and economically solve the misalignment of the magnetic head due to the difference in the installation direction of the conventional flexible magnetic disk device. It is possible to provide a device with stable performance that can easily cope with various installation postures of the magnetic disk device, and it is also possible to standardize the various systems of flexible magnetic disk devices on the user side of the flexible magnetic disk device. It is something to tighten.

The following description will be made based on an embodiment shown in the drawings.
FIG. 1 is a schematic plan view of an example of a double-sided flexible magnetic disk device, in which 1 is a spindle mechanism that becomes the center of rotation of the medium when a flexible magnetic recording medium is mounted (not shown in this figure). , 2 is a carriage portion on which the magnetic head 3 is mounted, 4 and 5 are guide rods that guide the linear reciprocating motion of the carriage, and 6 is a device that makes the magnetic head non-contact with the flexible magnetic recording medium when the magnetic head is not in read/write operation. Solenoid mechanism, 7 is guide rod 4,
A fixing plate 8 fixes 5 to the frame, and 8 fixes a drive band 10 with screws 9 at one end of the carriage. 11 is a pulley fixed on the output shaft of the step motor 12. 13 is idler and band 1
The end of the band with 0 wrapped around it is fixed on the pulley 11. Further, reference numeral 14 denotes an idler fixing fitting, which holds a spring structure for applying appropriate tension to the band 10 (not shown).

FIG. 2 is a diagram showing the principle of the present invention when the carriage drive unit shown in FIG. The lever 18 is a part of the counterweight structure and is configured to engage only one of the projections 15 on the band and the reciprocating movement of the band by the step motor. Further, the counterweight 17 is held by guide rods 19 and 20 so that it can follow the reciprocating movement of the band.

Now, in FIG. 2, when the direction of arrow A is the direction of gravity of the device, when a movement input signal to a specified track on the flexible magnetic recording medium 21 is applied to the step motor, the pulley 11 rotates and the carriage 2 moves the band 10. The magnetic head 3 is moved to the specified track by moving in the direction of arrow B or C through the band 10, but since the mass of the carriage 2 is applied as a load torque to the step motor via the band 10, the step motor has to maintain its own torque and load. Try to determine the stopping position at an angle that balances the torque. Therefore, if there is no counterweight mechanism, the positioning of the head when the direction of arrow A is the direction of gravity is the same as the positioning of the head when the direction of gravity is the direction of arrows B, C, and D (perpendicular to the figure) in other figures. There will be a slight deviation from the position, and this will be A, B,
If devices are allowed to be installed in both the C and D directions, it often becomes difficult to ensure the overall positioning accuracy of the flexible magnetic disk device. However, in this invention, when direction A is the direction of gravity, which is a particular problem, the counterweight engages and moves with the protrusion of the band via the lever as the carriage stops and moves. Since the load torque due to the carriage mass and the load torque due to the balanced counterweight are added, correct positioning of the magnetic head can be ensured. The lever 18 is integrally connected to a shaft 22, and the shaft 22 has a hole in the counterweight with a clearance for smooth movement, and a spring 23 is provided at the other end, so that the lever 18 always has a constant force. The structure is such that the spring 23 is pulled toward the E side of the counterweight, but when the gravity direction is in the A direction, the spring 23 leaves a certain gap between the lever 18 and the E side due to the weight of the counterweight. Power is set. This is because when the band moves in the direction of arrow b, the acceleration torque of the step motor is large and the natural falling speed of the counterweight cannot be followed, and the initial force is applied by the spring 23 so that the lever 18 and the protrusion 1 of the band are always connected.
5 in a contact state, and to provide a damping effect when the step motor suddenly accelerates or stops suddenly.

Another feature of the present invention is that when the direction of gravity is B, C, or D other than the direction A, the mass of the counterweight is applied at right angles to the guide rods 19 and 20, so the counterweight itself does not move. That means it doesn't work. For example, when the initial position of the counterweight is within the specified data track range of the magnetic head, the lever 18 and the protrusion 15 of the band
Even in a state in which the counterweight is engaged, once the carriage 2 moves to the specified track origin position in the C direction, the counterweight position basically does not move from then on. In other words, the present invention uses a counterweight to offset the excessive load torque due to the carriage applied to the step motor only when the orientation of the center of gravity of the device is in direction A, and when the orientation of the center of gravity of the device is in direction B, C, or D, the counterweight is activated. By separating the weights, the load torque applied to the step motor is balanced and the positioning of the magnetic head on a specified track on the flexible magnetic recording medium is controlled correctly.

Note that this example shows an example of the present invention, and many changes to the configuration etc. based on the present invention are conceivable.
According to this invention, when the installation orientation of the flexible magnetic disk device is changed, a counterweight is provided so that the load torque applied to the step motor due to the mass of the carriage is uniform regardless of the installation orientation of the device. Therefore, it is possible to obtain a flexible magnetic disk device in which the misalignment of the magnetic head due to the difference in the installation direction of the device can be solved extremely easily and economically.

[Brief explanation of the drawing]

FIG. 1 is a plan view of an example of a double-sided flexible magnetic disk device, and FIG. 2 is a configuration diagram showing an embodiment of the present invention. In the figure, 1 is a spindle mechanism section, 2 is a carriage, and 3 is a magnetic head,
4 and 5 are guide rods, 10 is a band, 11 is a pulley,
12 is a step motor, 13 is an idler pulley,
15 is a projection of the band, 17 is a counterweight, 18 is a lever, 19 and 20 are guide rods, 21 is a flexible magnetic recording medium, 22 is a shaft, and 23 is a spring. Note that the same or corresponding parts in the figures are indicated by the same reference numerals.

Claims (1)

[Claims] 1. A flexible recording medium having a carriage for positioning a magnetic head at a prescribed track position on a flexible magnetic recording medium, means for guiding the carriage, a step motor for driving the carriage, an idler, and a thin metal band. In a magnetic disk device, a projection provided on the band, a lever that engages in only one direction with respect to movement of the band, a counterweight coupled to the lever via an elastic body, and a counterweight for guiding the counterweight. A flexible magnetic disk device comprising means.