JPS61165869A - Positioning mechanism for magnetic head - Google Patents

Abstract

PURPOSE:To omit a large capacitor for retraction of a magnetic head and to attain the miniaturization of a magnetic head device, by shifting a plate by the wind pressure produced from revolutions of a disk in a power supply ON mode and by the force of a spring in a power supply OFF mode respectively to lock a carriage. CONSTITUTION:The wind pressure 5 produced from revolutions of a disk 2 surpasses the force of a spring 6 and moves a plate 8 until it touches a pin 9. Thus a carriage 1 can move smoothly. The pressure 5 is reduced gradually in a power supply OFF mode. Then the plate 8 moves toward the carriage 1 and the carriage 1 has a contact with the plate 8 regardless of the position of the part 1 in a power supply OFF mode. Then the plate 8 moves until it touches a stopper 15 at the side where the retraction of a magnetic head is decided. Thus the carriage 1 is locked there.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a magnetic disk device, and particularly to a magnetic disk device having a carriage lock mechanism.

[Background of the invention]

In modern small magnetic disk drives, the head and disk are in contact when the power is turned off, and when the power is turned on, the head floats up as the disk rotates to store and reproduce information, and when the power is turned off, the head and disk are in contact with each other. A contact start-stop system is used in which the head and disk are in contact with each other.

In such a disk device, the head load is approximately 9g,
Heads and disks are easily damaged by shocks and S-motion disturbances. For this reason, the role of the head retract structure is as follows: 11) To protect against leakage, when the power is off, be sure to move the head to the contact start/stop position (aSS zone)! (2) When the power is turned off, the head is locked at the contact start/stop position with a force that withstands the disturbance tolerance.

Conventionally, the head retract structure used is the structure shown in Figures 3 to 5. The head retraction structure used in 0-3 years old also uses a capacitor, which charges the capacitor when the power is turned on and discharges the capacitor when the power is turned off. This causes a current in the head retraction direction to flow through the voice coil 1d.
The iron piece 11 connected to the permanent magnet 10 is attracted and coupled to the carriage iron piece 12.

However, this method requires a 111-larger capacitor, and when the disk diameter increases from 14 inches to 8 inches, 5 inches, or even 55 inches, it does not fit within the outer diameter of the device. 121 [The gap between the head and the disk when the power is turned on is approximately 0.4 μm, and although it is necessary to keep the amount of dust as low as possible to less than class 100, it is possible to prevent dust from coming into contact with other metals using magnetizing force. There was a problem that this was likely to occur.

When the power is turned off, the head 16 is retracted by the force of the tension spring 13 in Figure 4, and by the force of the torsion spring 140 in Figure 5, and held at the contact start/stop position.

However, in this 1R model, the force of the spring is constantly applied even when head 1a is recording and reproducing information, and
When the button moves, the force generated from the voice coil motor 4 acts negatively when the head moves toward the inner circumference of the disk, and becomes positive when the head moves toward the outer circumference, impairing the force generated from the voice coil motor. It was also very difficult to control the movement of the head and required many electrical parts.

Incidentally, related devices K of this type include, for example,
JP-A-47-52809, JP-A-59-79
470 and Utility Model Application Publication No. 57-201697 are cited.

[Purpose of the invention]

The present invention has been developed by focusing on the diagonal point, and when the swing type carriage mechanism is busy and the power is turned on, the wind pressure generated by the rotation of the disk overcomes the force of the retracting spring, and The head is moved and held in a position that does not interfere with the head drive, and when the power is turned off, the wind pressure gradually decreases as the number of revolutions of the disk decreases, and the plate forcibly returns the carriage to the head retract position by the force of the retract spring, and then An object of the present invention is to provide a magnetic disk device that locks a carriage in a retracted position.

[Embodiments of the invention]

An embodiment of the present invention will be described in detail below using the drawings.

As shown in Fig. 1, the magnetic head positioning mechanism used in this embodiment includes a carriage section 1 consisting of a head 1'' and a coil 1d, and the carriage section 1 is supported by a sub-base 5 via a rotating shaft 2.A disk. Wind pressure (wind flow) 5 is generated by 20 rotations.The plate 8 has the shaft 7 as its center of rotation,
A tensile force is applied by the spring 6. Pin 9 is a stopper for plate 8. Note that it is better to reduce the coefficient of friction by covering the surface of the stopper with Teflon material.

However, to explain the operation of the above structure, when the power is turned on, the wind pressure 5 generated by the rotation of the disk 20 overcomes the force of the spring 6, as shown in Figure 5, and the grate 8 comes into contact with the pin 9. Then move the button to a position where the carriage 1 can be moved without any trouble. When the power is turned off, the wind pressure 5 gradually decreases as shown in Figure 5, and the plate 8 moves toward the carriage due to the force of the spring 6, so that the carriage part 1 contacts the plate 8 no matter where it is at when the power is turned off. The carriage 1 is moved four times until it contacts the stop 15 on the side determined to be the head retract, and the carriage 1 is locked at this position.

There is no need for a large capacitor for head retraction like in the past, making the device more compact, and since the plate uses Teflon material to reduce the number of friction threads, there is no metal-to-metal contact (preventing dust generation). In addition, since the force generated from the voice coil motor does not increase or decrease depending on the direction of head movement, as with the spring method, the number of electrical components for switching control depending on the direction of head movement can be reduced.

〔Effect of the invention〕

As described above, in the present invention, when the power is turned on, the wind pressure generated by the rotation of the disk overcomes the spring force, and the plate is moved and held in a position where it does not interfere with the head drive, and when the power is turned off, the rotational speed of the disk decreases. As the wind pressure gradually decreases, the plate moves due to the force of the spring no matter where the head is located, forcing the carriage to return to the head retract position, and the spring force also increases at the retract position, that is, at the stopper between the carriage and the plate. This force is used to lock the carriage, so (1) there is no need for a large capacitor for rudder retraction, as is the case with conventional systems, and the device can be made more compact. If Teflon material is used for this purpose, there will be no metal-to-metal contact and dust generation can be prevented. Furthermore, (3) the force generated from the voice coil motor does not increase or decrease due to the pressure in the direction of movement of the head, as in the case of a spring system, so the number of electrical components for switching control depending on the direction of movement of the head can be reduced.

[Brief explanation of drawings]

FIG. 1 is a front view showing an embodiment of the magnetic head positioning mechanism according to the present invention when the power is turned off. Figure 2 is a diagram showing the positioning mechanism shown in Figure 4 when the power is turned on. Figure 5 is a front view of a capacitor-type retract type magnetic head positioning mechanism according to the prior art.
FIG. 4 is a front view of a conventional tension spring type magnetic head positioning mechanism. FIG. 5 is a front view of a conventional torsion spring type magnetic head positioning mechanism. DESCRIPTION OF SYMBOLS 1... Carriage, 1a... Head, 1d... Coil, 2... Head rotation axis, 5... Sub pace, 4
...Voice coil motor, 5...Wind pressure (flow of wind) due to disc rotation, 6...Spring, 7...Plate rotating shaft, 8...Plate, 9...Bin, 10
... Magnet, 11... Iron piece, 12... Carriage iron piece, 13... Spring, 14... Torsion spring, 15... Head movement range setting stopper.

Claims (1)

[Scope of Claims] A magnetic disk comprising a rotationally driven magnetic disk, a carriage that rotationally supports a magnetic head, a drive section that rotationally drives the carriage, and a shroud that integrally covers the carriage and the drive section. The disk drive includes a plate that is rotatable around one end adjacent to the carriage, and the plate engages with the carriage to lock the carriage when the magnetic disk stops rotating, and when the magnetic disk rotates, the plate is rotated by wind pressure. A magnetic disk device characterized in that the lock is released by rotating.