JPH04364280A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To evade a collision of magnetic head and magnetic disk at the non- operating time of a device and to prevent both of them from damage. CONSTITUTION:The magnetic heads 7, 9 to record/reproduce by slightly floating from the magnetic disk 1 are mounted on one end of head arms 15, 17 through 1st piezoelectric elements 11, 13, and another end of the head arms 15,17 are mounted on a head carriage 37 through 2nd piezoelectric elements 33, 35 which are displaced so as to make the magnetic heads 7, 9 separate in the specified amount from the surface of magnetic disk 1 at the non-operating time of the device.

Description

[Detailed description of the invention]

[Object of the invention]

0002

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk device in which a magnetic head floats a small amount relative to a recording medium to perform recording and reproducing operations.

0003

[Prior Art] Generally, in a magnetic disk drive, a magnetic head is supported by a suspension mechanism in a state where it is pressed against a magnetic disk surface with a predetermined pressing force. Record and playback is performed while floating a small amount. The above suspension mechanism is attached to a swing arm that swings and rotates by a drive device called a voice coil motor, and the swing of the swing arm causes the magnetic head to seek in the diametrical direction of the magnetic disk and move to a predetermined information track. It will be positioned.

[0004] In such a magnetic disk device, the magnetic head contacts the magnetic disk surface when the device is not operating when the magnetic disk is not rotating, but when the device is operating and the magnetic disk is rotating, the magnetic head contacts the magnetic disk surface. It floats a small amount against the surface, and the contact start/stop (C
SS) method.

[0005]

Incidentally, in recent years, compact and lightweight personal computers such as laptops or notebooks have become popular, and the magnetic disk devices installed in these computers are becoming increasingly smaller. Such small magnetic disk drives are at high risk of being subjected to shocks, and in the case of personal computers such as the laptop type mentioned above, they are often moved and transported, so they are susceptible to shocks when the device is not in operation. It becomes.

[0006] When a shock is applied to a magnetic disk drive,
In devices that employ the CSS method described above, when the device is not operating, the magnetic head bounces on the magnetic disk and the two collide with each other, causing damage, or even if the device does not bounce, it rubs sideways and slides, causing damage. There are problems such as. As a result, the functions of the magnetic disk and the magnetic head deteriorate, leading to a decrease in reliability.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to avoid collision between a magnetic head and a recording medium when the apparatus is not in operation, thereby preventing damage to both of them.

[Configuration of the invention]

[0009]

[Means for Solving the Problems] In order to achieve the above object, the present invention connects a magnetic head for recording and reproducing data to a recording medium to one end of a head arm, and connects the other end of the head arm to a piezoelectric It is attached to a support member via an element.

The present invention may also be configured such that a magnetic head for recording and reproducing data on a recording medium is attached to a support member via a spring member and a piezoelectric element.

[0011]

[Operation] When the apparatus is not in operation, the piezoelectric element is displaced to move the magnetic head a predetermined distance away from the surface of the recording medium. At this time, even if an impact is applied to the device and a force is applied to the magnetic head in a direction toward, for example, the surface of the magnetic disk, the magnetic head and recording medium are separated by a predetermined amount, so collision between the two is avoided.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic diagram of the internal structure of a magnetic disk device showing an embodiment of the present invention. A magnetic disk 1 as a recording medium can be rotated at a predetermined speed by a spindle motor 3 about a shaft 5 mounted on an apparatus base 4. A pair of upper and lower magnetic heads 7 and 9 that record and reproduce information on the magnetic disk 1 are connected to highly rigid head arms 15 and 1 via first piezoelectric elements 11 and 13, respectively.
It is attached to the tip of 7. First piezoelectric element 11,1
3 extends vertically in the figure when voltage is applied (Figure 1), and contracts when the voltage is removed (Figure 2). It is executed by a control circuit (not shown) while a data read/write command or a pre-command (for example, a unit select command) indicating the same is given to the magnetic disk device.

FIG. 3 shows the upper magnetic head 7 in FIG.
FIG. 4 is a bottom view of FIG. 3. Between the magnetic head 7 and the first piezoelectric element 11 is a plate spring 1 which is curved convexly toward the magnetic head 7.
9 is provided. The magnetic head 7 has a slider 23 whose surface facing the magnetic disk 1 forms an air bearing surface surface 21 that receives the airflow shown by the arrow B generated by the rotation of the magnetic disk 1, and the slider 23 forms an air bearing surface surface 21 that receives the airflow shown by the arrow B generated by the rotation of the magnetic disk 1. Cutouts 25 and 27 for generating negative pressure are formed on both the upper and lower sides in FIG. 4 near the end. On the air outflow end side between each of the notches 25 and 27,
An electromagnetic transducer 29 is provided for recording and reproducing data on the magnetic disk 1. In the electromagnetic conversion section 29, a core 31 forming a magnetic circuit is embedded in the slider 23, and the core 31 is provided with a magnetic gap and a coil (not shown). Regarding the magnetic head 9 on the lower side,
A plate spring 32 is interposed between the magnetic head 9 and the head arm 17, and the configuration of the magnetic head 9 itself is similar to that of the magnetic head 7.

The proximal ends of the head arms 15 and 17 are attached to one end of a head carriage 37 as a support member via second piezoelectric elements 33 and 35, respectively. The second piezoelectric elements 33 and 35 are in a contracted state (FIG. 1) in the vertical direction in the figure when a voltage is applied, and are in an expanded state (FIG. 2) when the voltage application is removed. This is performed by a control circuit (not shown) when the device is powered on. A voice coil 39 is attached to the other end of the head carriage 37, while a yoke 41 forming a magnetic circuit is attached to the device base 4. , permanent magnet 43
is attached to constitute a voice coil motor that rotates the head carriage 37 about the shaft 45.

In the magnetic disk device configured as described above, when the device is powered off, the first piezoelectric elements 11 and 13 are in a contracted state, and the second piezoelectric elements 33 and 35 are in a contracted state, as shown in FIG. It will be in an extended state. Second piezoelectric element 3
3 and 35 extend by a predetermined amount, the magnetic heads 7 and 9 are positioned a predetermined distance away from the magnetic disk 1. Therefore, in this state, a shock is applied to the device, and the magnetic head 7,
For example, even if the magnetic head 9 receives a force in the direction toward the magnetic disk 1, the magnetic heads 7, 9 and the magnetic disk 1 are separated by a predetermined amount, and the head arms 15, 17 have high rigidity, so that a collision between them will not occur. This avoids damage to both parties.

When the power of the device is turned on, a necessary voltage is applied to the second piezoelectric elements 33 and 35 by the control circuit. As a result, the second piezoelectric elements 33 and 35 contract in the vertical direction in the figure as shown in FIG. 1, causing the magnetic heads 7 and 9 to approach the magnetic disk 1. At this time, the magnetic disk 1 starts to rotate, but the first piezoelectric elements 11 and 13
continues to shrink, and the gap between the magnetic heads 7, 9 and the magnetic disk 1 is, for example, 0.5 μm or more, which is kept wider than the state in which data can be read and written. This prevents collision between the magnetic heads 7 and 9 and the magnetic disk 1 when the power is on.

Next, while a data read/write command or a pre-command (for example, a unit select command) indicating the same is given to the magnetic disk device, a control circuit (not shown) applies a necessary voltage to the first piezoelectric voltage. Element 11,1
3 is applied. As a result, the first piezoelectric elements 11,1
3 extends vertically in the figure as shown in FIG. 1, and the magnetic heads 7 and 9 approach the magnetic disk 1 to the point where they can read and write data, and the gap between them narrows. In this state, the magnetic disk 1 has reached a predetermined rated rotational speed, and the airflow generated by the rotation of the magnetic disk 1 enters between the magnetic heads 7 and 9 and the magnetic disk 1, creating positive pressure. to form an air film, and the leaf spring 19,
In balance with the pressing force of 32, the magnetic heads 7 and 9 are levitated by a minute amount (about 0.3 μm). Accordingly, negative pressure is generated in the notches 25 and 27 of the slider 23, and the floating posture of the slider 23 is stabilized by this negative pressure.

In this way, the second piezoelectric elements 33, 35 move the magnetic heads 7, 9 away from the magnetic disk 1 by a predetermined amount when the power is turned off, thereby preventing collision between the magnetic heads 7, 9 and the magnetic disk 1. function, while the first piezoelectric element 11
, 13 have a function of ensuring an optimum flying height for recording and reproducing operations and improving recording and reproducing characteristics.

By the way, the magnetic disk 1 in a rotating state is
Since the rotational speed is faster and the air film pressure is higher on the outer circumferential side than on the inner circumferential side, the flying clearance of the magnetic heads 7 and 9 relative to the magnetic disk 1 at the same rotational speed is narrower on the inner circumferential side and wider on the outer circumferential side. For this reason, the recording density needs to be set according to the outer periphery side where the flying gap is wide. However, when the magnetic heads 7 and 9 are on the outer periphery side, the first piezoelectric elements 11 and 13 are set so as to narrow the flying gap. By adjusting the control voltage, it is possible to set the recording density to be high according to the inner circumferential side, and it is possible to improve the recording density of the entire magnetic disk.

[0021] In general, when looking at one sector among a plurality of sectors divided in the circumferential direction on a magnetic disk, although the recording area in the circumferential direction is longer on the outer circumferential side than on the inner circumferential side, Due to the above-mentioned difference in floating clearance between the inner and outer circumferential sides, conventionally, the recording area on the outer circumferential side was aligned with the inner circumferential side, and a wasted area existed on the outer circumferential side. However, by adjusting the control voltage for the first piezoelectric elements 11 and 13, the magnetic head 7 on the outer circumferential side
, 9, the recording operation can be performed over the entire long recording area on the outer circumference side, increasing the recording capacity on the outer circumference side and increasing the recording capacity of the magnetic disk as a whole.

In the above embodiment, the slider of the magnetic head was explained using a negative pressure type slider having a notch, but two air guide grooves were provided in the air flow direction on the surface facing the magnetic disk. It may also be a positive pressure type.

[0023]

[Effects of the Invention] As explained above, according to the present invention, the magnetic head is separated from the recording medium surface by a predetermined amount due to the displacement action of the piezoelectric element when the device is not in operation, so that no impact is applied to the device at this time. Even so, collision between the magnetic head and the recording medium can be avoided and damage to both can be prevented.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of the internal configuration of a magnetic disk device during device operation, showing an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a device inside the magnetic disk device shown in FIG. 1 when it is not in operation.

FIG. 3 is an enlarged view taken in the direction of arrow A in FIG. 1;

FIG. 4 is a bottom view of FIG. 3;

[Explanation of symbols]

1 Magnetic disk (recording medium) 7,9 Magnetic head 15, 17 Head arm 33, 35 Second piezoelectric element

Claims (2)

[Claims] 1. A magnetic device, characterized in that a magnetic head for recording and reproducing data on a recording medium is connected to one end of a head arm, and the other end of the head arm is attached to a support member via a piezoelectric element. disk device. 2. A magnetic disk device characterized in that a magnetic head for recording and reproducing data on a recording medium is attached to a support member via a spring member and a piezoelectric element.