JPH02226560A - Head positioning device - Google Patents

Abstract

PURPOSE:To perform the positioning of a head at high speed and with high accuracy by using an arm of light weight and with low rigidity by providing a sensor to detect deformation, an element to generate a force corresponding to input, and a controller to suppress the deformation. CONSTITUTION:A strain gage 6 detectable a strain and a piezo-electric element 7 able to generate the force to correct the strain are mounted at the side plane of the arm 2. When a device is operated and the strain occurs in the arm 2 in a direction of arrow head in figure, the volume of the deformation of the arm 2 is shown as the change of the resistor of the gage 6. The change of the resistor is detected as a voltage by a bridge circuit 8, and it is applied on the element 7 via a differential amplifier 9, an LPF 10, a phase compensation circuit 11, and a piezo-electric element driving amplifier 12, and the element 7 generates the force required for the correction of the strain of the arm 2. Thereby, since the strain of the arm 2 is suppressed by the deformation in a reverse direction of the element 7, and rigidity for the strain of the arm 2 can be heightened, the mechanical resonance point of the device can be increased equivalently, and the positioning with high accuracy can be performed.

Description

[Detailed Description of the Invention] [Chaotic Purpose] (Industrial Application Field) The present invention relates to a head for recording or reproducing a magnetic disk FC [etc. This invention relates to a vertical positioning device for positioning.

(Prior Art) In a disk storage device such as a magnetic disk, there are a transducer (magnetic converter) for recording and reproducing information, and an 8-channel converter for positioning information on a disk in a specific area where information can be stored. Recently, as the capacity and speed of the tltc[l has increased, there is a need for a device that can position the V and C at high speed and with high precision.

As a conventional head positioning device, there is a rotary actuator for a magnetic disk as shown in FIG. 6, for example. The head gimbal assembly 1 is supported by an arm 2, and the arm 2 is supported by a carriage 4 rotatable about a rotation axis 3. Therefore, in a normal magnetic disk drive, the head section reads the positioning information recorded on the magnetic disk storage medium, drives the voice coil motor 5 based on this positioning information, and positions the magnetic disk on the desired track. Closed loop control is used.

In order to perform highly accurate positioning in the O-disk 1ift mechanism as described above, it is necessary to widen the control band of the closed loop control system for boat fishing. However, this control band is usually ca IJ fji 4. It is limited by the mechanical resonance point of arm 2, etc. Therefore, it is well known that in order to achieve highly accurate positioning, it is sufficient to increase the rigidity of the carriage 4% arm 2, etc., and to raise their mechanical resonance points. On the other hand, it is desired to move the vertical/vertical moving mechanism at high speed. Carriage 4. There are 8 tips to make the arm 2nd class and AT. However, there was a problem in that increasing the rigidity of the inside of the shell would increase the mass, which would limit the ability to increase the rigidity of the arm 2, etc.

In order to solve these problems, Japanese Patent Application Laid-Open No. 63-2579
There is also a prior art that is equipped with a vibration absorbing mechanism as disclosed in Japanese Patent No. 67. As shown in FIG. 7, a carriage 4 on which an arm 2 equipped with a magnetic head 21 is mounted is directly moved and positioned by a movable coil 22 fixed to the carriage. A weight 26. Spring parts 25. Anti-vibration parts 27
A heat absorption device S29 is attached, the natural frequency of the vibration absorption mechanism is almost equal to the natural frequency of the main body of the galley,
Furthermore, the vibration direction of the vibration absorption mechanism is the same as the carriage drive direction (
(X direction)? It is a feature.

In such a conventional example, the disadvantage is that the carriage assembly swings, and the vibration absorption mechanism, which has a natural frequency of 2 that is almost close to the resonance frequency φ of the carriage, absorbs the resonance energy of the carriage and reduces the amplitude at the time of resonance. The number of things to do was solved. However, resonance at high frequencies was still unavoidable.

(Problems to be Solved by the Invention) As described above, with the conventional head positioning device, it is difficult to realize a lightweight and highly rigid arm, and it is difficult to raise the mechanical resonance point, so the drawbacks related to arm vibration are This was compensated for by reducing the amplitude by 2, but there was a limit to how high the head positioning could be due to closed loop control.

It is an object of the present invention to eliminate the above-mentioned drawbacks and to provide a head positioning device which can be positioned at high speed and with high accuracy, and which can be used for vertical positioning and positioning.

[Structure of the invention]

(Section @ and Means for Solving the Problem) In order to achieve the above object, the present invention comprises: (1) recording or reproducing which requires positioning; A head positioning device consisting of a carriage capable of moving a recording section, and a drive section that positions the hept section by moving the carriage and the carriage.
cli4, the arm t'$ has at least one element that detects its deformation S, at least one element that generates a force 2 in response to the input group, and a force that is applied to the element based on the output of the sensor. The invention is characterized in that it includes a control unit that creates a control signal to be applied.

(Function) In the head rfL[lt determining device?
In this case, the sensor detects deformation of the arm caused by insufficient rigidity of the arm, and based on the output of the sensor, the control device sends a control signal P that generates a force to suppress the deformation of the arm. signal? This suppresses the deformation of the arm. Therefore, while conventional head positioning devices could only reduce the amplitude of arm deformation,
The present invention can raise the mechanical resonance point by equivalently ≦
(Example) Hereinafter, the present invention will be described in detail with reference to the drawings.

Example 1 Is Figure 1 the invention? Figure 1, which is a plan view of an embodiment implemented in a rotary 7 unit for magnetic disk recording, shows a head cymbal with positioning P8.
Assembly I GC arm 2 # is supported, arm 2
A rotatable carriage 44 is supported around a rotation center 4113. Therefore, using closed loop control, the positioning information recorded on the magnetic disk recording medium is read from the magnetic field, and the voice coil motor 5 is activated to use this positioning information. The magnetic head is positioned and controlled to a desired position #C. The arm 2 also has a strain gauge 6 on its side that can detect strain.

A piezoelectric element 7 capable of generating mold is attached to correct the distortion. Furthermore, the change in resistance of the strain gauge 6 is converted into a voltage by the bridge circuit 8, and the voltage is
Differential amplifier9. Low pass filter to, r! :L phase compensation circuit 11. The pressure '4 passes through the pump 12 and the pressure 'g
It is added to L element 7.

The actual vAkc head positioning device is actuated and the arm 2 is shown in plan view in a distorted prone position in FIG.

If arm 2 is distorted in the direction of the arrow, arm 2
0's, the shape appears as a change in the resistance of the strain gauge 6. This change in zero resistance is detected as '4FE' by the pre-current circuit 8, and the differential amplifier 9. Low pass filter 10. Phase compensation circuit 11. Pressure '4: The piezoelectric element 7 passes through the P drive amplifier 12, and the piezoelectric element 7 absorbs the distortion of the arm 2 (
Variant) fi - Generates the force necessary to correct. Therefore, the deformation of the arm 2 is the deformation of the forceps 70 in the opposite direction.
Since the rigidity against distortion of the arm 2 is increased by being suppressed from ζ, the A mechanical resonance point becomes equivalently high, and highly accurate positioning can be performed.

Embodiment 2 FIG. 3 is a side view of the case in which the strain gauge 6 and the piezoelectric element 7 are attached to the upper and lower surfaces of the arm 2 in the above embodiment 1, and the other parts are the same. In this case, the rigidity against deformation of the arm 2 as shown in FIG. 4 can be increased.

Embodiment 3 FIG. 5 is a side view of an example in which the present invention is implemented in a magnetic disk drive Q linear actuator, and the other aspects are the same as Z)% Identification 1 and 2 above.

In addition, in Examples 1 and 2.3, the output of the strain gauge is observed, and the output is input into the processor as a strain and digital quantity using Δ/D conversion or other means, and the value is created in advance from that value. Vote for pressure from the table: F? It is also possible to determine and control the voltage 6 for driving.

2. The unexploded CLLL is not limited to the magnetic disk device as in the above example, but can also be used in O positioning devices such as Heshito in other storage devices.

[Effects of the Invention] As described in detail above, the present invention suppresses the deformation of the arm when it gets hot, so the mechanical resonance point can be made even higher. Using a lightweight arm with low 1411 resistance, it is possible to perform high-speed and high-precision positioning.

[Brief Description of the Drawings] Figure 1K1 is a block diagram of an embodiment of the present invention implemented in a rotary actuator, Figure 2 is a thousand-sided diagram showing the deformation of the arm O in Figure 5, and Figure 3 is a block diagram of an embodiment of the present invention implemented in a rotary actuator. The # side view of the example implemented on the rotor IJ +1 actuator, Figure 4 is II! h3 diagram Q
Fig. 5 is a configuration diagram 1wc6e of an embodiment in which the present invention is implemented in a linear actuator.
ii! l is the conventional Q that does not have anything to suppress vibration.
Head positioning device cog diagram. FIG. 7 is a top view of a gear 912 assembly showing an example of a conventional O-head uprighting device equipped with a vibration absorption mechanism. l...head gimbal assembly, 2...arm, 3...rotation@, 4...carriage, 5...
Voice coil motor, 6... strain gauge, 7... piezoelectric element. 8... Bridge circuit, 9... Differential amplifier, 10...
・Low pass filter 11...text compensation circuit, 12
...Pressure element drive amplifier. Agent Patent Attorney Nori Kon I Mitsuyuki Muroma Matsuyama

Claims (1)

[Claims] A head unit that performs recording or reproduction that requires positioning, an arm unit that supports this head unit, a carriage that is capable of moving this arm unit, and a drive that positions the head unit by moving this carriage. a head positioning device comprising: at least one sensor provided on the arm section to detect deformation thereof; at least one element generating a force according to an input; A head positioning device comprising: a control device that generates a control signal to be applied to an element.