JPH08255410A - Magnetic disc apparatus - Google Patents

Abstract

PURPOSE: To obtain a head/disc adhesion releasing force sufficiently great at the start of rotating a disc even in a small magnetic disc apparatus with a lower power consumption which has a smaller starting torque of a disc spindle motor. CONSTITUTION: In a magnetic disc apparatus which is adapted to hold a head slider 104 on the surface of a disc on the inner circumference side in contact therewith during the stoppage of the rotation of the disc, the radius of a contact holding zone on the disc surface is made smaller in substance than the radius of a zone in which the head slider slides when lifted from or landing on the surface of the disc or the radius of a data recording zone on the surface of the disc. At the start of rotating the disc 105, firstly, with the head slider held on the surface of the disc in contact, the disc is started to rotate at a low speed and then, the head slider is moved to the outer circumference side on the surface of the disc to shift the disc to a high speed rotation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk device such as a hard disk drive and, more particularly, to a magnetic disk device adopting a head / disk detackification method, which is suitable for use in a small-sized device with low power consumption. Is.

[0002]

2. Description of the Related Art As for the size of computers, desktops, laptops, notebooks, notebooks, and so on are being miniaturized. Further, along with the progress of high recording density technology, downsizing of magnetic disk devices in the market is called so-called 3.5 inch type to 2.5 inch type, 1.8 inch type, and 1 Progressing to 3 inch type. A magnetic disk device built in or detached from a portable computer having a size of a notebook or less has become a mainstream one having a size of 2.5 inches or less.

Next, the reduction of power consumption of a small magnetic disk device will be described. Card-type removable magnetic disk devices, which have become widespread with the miniaturization of magnetic disk devices, are standardized to include mechanical connection and disconnection and electrical connection interfaces. The Japan Electronic Industries Association (JEIDA) and the US PCMCIA (Person
al Computer Memory Card International Association)
There is a standard specification for IC memory cards for personal computers that we have been cooperating with.

Initially, this was not intended for the magnetic disk device, but it has been expanded to include the magnetic disk device and the like as the magnetic disk device is miniaturized. In the standard specifications of this IC memory card for personal computer,
The operating environment can be set so that it can be used on the system or with other cards in the system, and if the operating environment provided by the card does not satisfy the operating environment required by the system, the system will You can refuse to use it. This operating environment includes parameters relating to power supply condition information.

The above parameters include standard operating power supply voltage, minimum operating power supply voltage, maximum operating power supply voltage, continuous power supply current, maximum value of average current for 1 second, maximum value of average current for 10 milliseconds, power down mode. The required supply current and the like are included. As described above, a small magnetic disk device such as a card-type magnetic disk device that is expected to be used mainly for portable information equipment with a built-in battery is required to have low power consumption.

As a typical conventional technique for reducing power consumption,
U.S. Pat. No. 4,933,785 (corresponding Japanese application;
As disclosed in JP-A-3-503101), an operation mode is a sleep mode in which other circuit functions are stopped while leaving a minimum interface connection function with a host required for restarting, Spindle motor is in a rotating state, some servo functions are operating and the data recording / reproducing circuit is in a stopped state, idle mode, write / read / seek normal operation mode, etc. In the mode, there is a method of suppressing power consumption in a circuit part that is not necessary for its function.

This method has the effect of reducing the power consumption in an average usage state. However, not less than this, it is also important to reduce the power consumption of individual circuit components including the motor. For this reason, in many disk spindle motors for small magnetic disk devices, the initial starting torque tends to be small due to the limitation of the maximum current and the reduction in size and thickness. The same applies to the torque of the rotary voice coil motor for driving the head actuator.

Next, the adhesion phenomenon between the head and the disk will be described. In a contact start stop (CSS) type magnetic disk device, after the disk rotation is started in a contact stopped state in which the head slider is pressed against the disk surface, a predetermined peripheral speed is reached and the head slider is sufficiently moved from the disk surface by dynamic pressure. The head slider slides on the disk surface while making contact with the surface of the disk until it floats. Therefore, in order to improve the wear resistance of the head slider and the disk surface, a surface lubricant is used to cover the disk surface. Further, recently, a contact type magnetic disk device is about to be commercialized in order to achieve a higher recording density than that of the head floating type magnetic disk device, but in this case, the wear resistance is also improved. Therefore, the surface lubricant is used.

However, when the head slider and the disk, which have extremely high flatness, are in a state where the adhesion is stopped for a long time through the surface lubricant, an adhesion phenomenon often occurs. This sticking phenomenon causes a startup failure of the magnetic disk device. Therefore, various devices have been devised to make the sticking phenomenon less likely to occur and to release the sticking state.

[0010]

As a method for preventing the above-mentioned adhesion from occurring fundamentally, Japanese Patent Application Laid-Open No. 1-134770.
There is a lamp loading technique disclosed in Japanese Laid-Open Patent Publication No. 3-503101. In this system, a head suspension is held by a tapered holding member mounted on the disk surface, and the head slider is held in non-contact with the disk surface.

However, with this method, it is necessary to secure an additional disk space for non-contact holding and to add a holding member.

Further, as a method of making adhesion less likely to occur, the contact start / stop zone on the disk surface as disclosed in Japanese Patent Publication No. 57-8530 has a rough surface accuracy to reduce the flatness. There is a so-called zone texture technique.

However, the effect of this method is in relation to improvement in wear resistance and trade-off, it is difficult to completely prevent sticking, and the manufacturing cost increases.

[0014] Further, various methods of devising the characteristics of the surface lubricant have been tried, but at present, it is difficult to completely prevent sticking only by this.

Further, Japanese Unexamined Patent Publication No. 6-203514 discloses a method of reducing the stiction (static friction force) by providing a protrusion on the head slider to reduce the contact area with the disk surface. .

However, in this method, it is necessary to fully consider the avoidance of the risk of sliding between the head slider and the disk surface due to the protrusion provided on the head slider.

On the other hand, as a method for releasing the adhesion, there is a method using the starting force of a rotary voice coil motor for driving a disk spindle motor or a head actuator. For example, Japanese Patent Publication No. 57-60707 and U.S. Pat. No. 4,542,429 disclose a method of releasing the adhesion by moving the head slider in the radial direction of the disk immediately before the disk starts to rotate. Further, Japanese Patent Publication No. 61-61191 discloses a method of releasing the adhesion by vibrating the head slider by a voice coil motor for driving a head actuator when the disk starts to rotate. Furthermore, Japanese Patent Laid-Open No. 61-66780 discloses a method of releasing the adhesion by pressing a head actuator against an elastic stopper by an actuator motor and finely moving the head slider in the disk radial direction before starting the rotation of the disk. It is disclosed.

However, these known techniques for releasing the adhesion are sufficient even in a compact and low power consumption magnetic disk device in which the starting torque of the disk spindle motor and the torque of the rotary voice coil motor for driving the head actuator are small. No technique has been shown to provide detackification.

As another method for releasing the adhesion, the technique disclosed in JP-A-6-208771 is known. This prior application discloses a method of releasing adhesion by providing a plurality of vibrating elements in a head slider portion and vibrating the head slider in various vibration modes.

However, according to this method, the head slider portion is complicated and the manufacturing cost is high.

That is, none of the above-mentioned conventional techniques is a head / disk detackification method suitable for use in a compact and low power consumption magnetic disk device, but a compact and low power consumption magnetic disk device such as a battery built-in type. There has been a demand for realization of a head / disk detackification method suitable for use in.

Therefore, the technical problem to be solved by the present invention is to solve the above-mentioned problems of the prior art. The purpose is to start the disk spindle motor and drive the head actuator. The object of the present invention is to realize a head / disk detackification method suitable for use in a small-sized and low-power-consumption magnetic disk device having a small rotary voice coil motor torque.

[0023]

In order to achieve the above-mentioned object, the present invention provides a magnetic disk device of the type in which a head slider is held in contact with the disk surface on the inner peripheral side when the disk rotation is stopped. The radius of the contact holding zone was set to be substantially smaller than the radius of the zone in which the head slider glides or lands on the disk surface, or the radius of the data recording zone on the disk surface. More preferably, the contact holding zone on the disk surface is near the disk rotation axis. Then, at the time of disk rotation start, with the head slider kept in the above contact holding state on the disk surface, the disk is first rotated and started at a low speed rotation state, and then the head slider is moved toward the outer peripheral side on the disk surface. The magnetic disk device is provided with means for executing a control procedure for shifting the disk to a high-speed rotation state.

More preferably, the disk is adhered / attached to the spindle motor, and a through hole is not provided in the center of rotation of the disk for holding the head slider in contact therewith, and the contact holding zone on the disk surface is formed. It was possible to make it closer to the disk rotation axis.

[0025]

By bringing the contact holding zone of the head slider close to the vicinity of the disk rotation axis, the radius from the center of disk rotation to the point of action of the head / disk detackifying force can be made small, so the starting torque of the disk spindle motor is small. Even with a low power consumption magnetic disk device, a sufficient head / disk adhesive release force can be obtained at the time of disk rotation start.

[0026]

The details of the present invention will be described below with reference to the illustrated embodiments. 1 and 2 are plan views of a magnetic disk device according to one embodiment of the present invention. FIG. 1 shows the head slider position and disk surface at the time of startup.
Shows the head slider position and the disk surface at the start of flying.

1 and 2, 101 is a magnetic disk device, 102 is an actuator, 103 is a head suspension, 104 is a head slider, 105 is a disk, 106 is a data zone, 107 is a flying and landing gliding zone, and 108 is A sliding zone for moving, a 109 contact holding zone, 110 is an adhesion releasing force F, 111 is a disk rotation axis, and 112 is a head slider sliding locus.

The HDA (head disk assembly) of the magnetic disk device 101 includes a disk 105, an actuator 102, a head suspension 103 connected to the actuator, and a head slider 104. The data side surface of the disk 105 is divided into several zones. That is, from the data zone 106 located on the outer peripheral side to the disk rotation axis 111, the levitation and landing gliding zones 107 are sequentially arranged.
The sliding zone 108 for movement and the contact holding zone 109 are configured to be located.

As shown in FIG. 1, the head slider 104, when the disk is in the rotation stopped state and at the start-up, is
The head suspension 103 receives a pressing force on the disk surface of the contact holding zone 109 in the vicinity of the disk rotation shaft 111 and holds the disk. Although not shown in the figure, the actuator 102 is held by a mechanical system or a so-called magnet latch system so that the head slider 104 does not inadvertently move to the outer peripheral zone when the disk rotation is stopped.

At the start of flying, as shown in FIG. 2, the head slider 104 moves from the contact holding zone 209 near the disk rotation axis 111 to the low speed rotation of the disk 105 as shown in the head slider sliding trajectory 112. After passing through the traveling gliding zone 108, it is pulled out to the levitating and landing gliding zone 107. After that, the disk 105 shifts to high speed rotation, and the head slider 104 receives the buoyancy of the air flow and starts to fly.

Incidentally, in the conventional CSS (contact start stop) type magnetic disk device, the contact holding zone is substantially the same as the levitation and landing gliding zone, and is located relatively near the middle circumference of the disk surface. Therefore, the disk portions corresponding to the moving sliding zone 108 and the contact holding zone 109 of the present embodiment shown in FIGS. 1 and 2 are conventionally occupied by holes for penetrating the spindle motor hub.

Here, when the head slider and the disk surface are in an adhered state, only the starting force of the spindle motor having a certain starting torque causes only the head slider and the disk as shown in the adhesion releasing force F110 of FIG. If the surface peeling force is applied, the head slider sticking position radius R and the maximum sticking release force F have an inverse relationship.

FIG. 3 is a graph showing the inverse proportional relationship between the head slider adhesion position radius R and the maximum adhesion release force F. In the figure, R ₁ is the radius of the contact holding zone 109, F ₁
Is the maximum adhesion release force that can be given by the spindle motor at this adhesion position radius R ₁ . R ₂ is the radius of the levitation and landing gliding zone 107, and F ₂ is the maximum adhesion release force that can be given by the spindle motor at this adhesion position radius R ₂ . Also,
R _OUT is the outermost radius of the data zone 106, and F _OUT is the maximum adhesion releasing force that can be given by the spindle motor at this adhesion position radius R _OUT .

As shown in this graph, the maximum adhesion releasing force F ₁ that can be given by the spindle motor in this embodiment is the maximum adhesion releasing force F _{2 that} can be given by the conventional CSS (contact start stop) type magnetic disk device. It is about 5 times. As a matter of course, the maximum adhesion release force F ₁ can be further increased by bringing the contact holding zone 109 closer to the disc rotation shaft 111.

Next, the start control and progress of the head slider position radius and the disk rotation speed in the magnetic disk device of this embodiment will be described in more detail. FIG.
6 is a graph showing activation control of a head slider position radius and elapsed time according to the present embodiment. Further, FIG. 5 is a graph showing the startup control of the disk rotation speed and the elapsed time according to this embodiment.

From time T ₁ to time T ₂ , the disk is started to rotate from the stopped state to the low rotation speed V ₁ . During this time, the head slider 104 remains held in the contact holding zone 109, and the head slider position radius remains R ₁ and does not change. Between times T ₂ and T _3, the holding of the head slider 104 in the contact holding zone 109 is released, and the head slider 104 is moved to the flying and landing gliding zone 107, so that the head slider position radius changes from R ₁ to R ₂ . During this time the disk rotation speed does not change remains slow rotation speed V _1.

Between times T ₃ and T ₄ , the head slider position radius is R ₂ , that is, the flying and landing gliding zone 107 remains, and the disk rotation speed is changed to the low rotation speed V.
Increase from ₁ to high rotational speed V ₂ . As a result, the head slider 104 receives the required air flow and floats above the disk surface.

A seek operation and a read / write operation are performed between times T ₄ and T ₅ , and the head slider position radius changes within the data zone 106 in accordance with the seek operation.

From time T ₅ to T ₆ , T ₇ , T ₈ , a series of stop operations are performed, and the stop operation is performed in the reverse order of the start operation from time T ₁ to T _4. .

When the head slider 104 is in the contact holding zone 109 and the moving sliding zone 108, the disk rotation speed is set to a low speed as described above. Even if the surface precision of is relatively rough, it is possible to suppress wear of the head slider and the disk. Therefore, if necessary, the surface texture of the contact holding zone 109 and the sliding zone for movement 108 may be made relatively rough by the zone texture technique.

As described with reference to FIG. 3, in the magnetic disk device of this embodiment, the maximum adhesion releasing force that can be given by the spindle motor is about 5 as compared with the conventional CSS (contact start stop) type magnetic disk device. Since it can be doubled or more, it is necessary for the head suspension 103, in particular, a minute and easily deformable head slider support spring, a so-called gimbal, to have means for preventing plastic deformation or damage.

FIG. 6 is a view of the head suspension 103 portion of this embodiment as seen from the side opposite to the disk, and FIG. 7 is the head suspension 103 at the time of applying an adhesion releasing force.
The figure which looked at the part from the disk opposite side is shown.

A gimbal 122 is attached to the tip end of the load arm 121 by spot welding at a gimbal spot welding point 126. Further, a head slider core portion 123 is attached to the tip end side of the gimbal 122 by adhesion. The gimbal 122 functions as a minute head slider support spring that applies a pressing force to the head slider core portion 123. Further, a head signal thin wire 125 is drawn out along the load arm 121 from the head winding in the head slider core portion 123. In this embodiment, the tip side of the load arm 121 is
Normally, the head slider core portion 123 does not come into contact with the head slider core portion 123 and extends so as to surround it. And the load arm 121
A portion of the front end of the head facing the head slider core portion 123 is provided with a function as a stopper 124.

When the head slider core portion 123 receives a large adhesion releasing force from the disc surface in a state where the head slider and the disc surface are adhered, the spring portion of the gimbal 122 is elastically deformed, and the head slider core portion 123 is Since the gimbal 122 moves in the direction of the stopper 124 but contacts the stopper 124, the deformation of the gimbal 122 can be suppressed to a predetermined amount or less. Therefore, the gimbal 122 is not plastically deformed or damaged. It should be noted that, compared to the minute spring portion of the gimbal 122, the other portion of the head suspension 103 can be designed to have sufficient strength against the adhesive release force, and damage can be prevented.

FIG. 8 shows a cross section of the disk device according to the present embodiment, and shows the state at the head slider position at the time of holding and starting.

As shown in the figure, in this embodiment,
Head slider core portion 1 of the head suspension 103
Since the data surface side surface of the disk 105 facing the disk 23 has no hole or recess at the disk rotation center, the head slider core portion 123 can be held in contact with the disk rotation center axis in the vicinity thereof. Disk 105 and spindle motor 13
The two opposing mounting surfaces are adhesively fixed to each other by an adhesive layer 134. A concave portion 131 is formed at the center of the facing surface of each of the disk 105 and the spindle motor 132.
Since the concave portion 131 at the center of disk rotation and the convex portion 133 at the center of rotation of the spindle motor are fitted to each other, it is configured so that the two can be easily and reliably aligned during bonding. There is. In FIG. 8, 135 is a circuit board and 136 is a circuit component.

Here, the disk 105 of the above-mentioned embodiment.
Although only one side is the data side, by using a spindle motor with a disk mounting hub radius that is sufficiently small, the contact holding zone of the head slider can be maintained even in a magnetic disk drive having a plurality of disks with both sides being the data side. Needless to say, it is possible to bring it close to the vicinity of the disk rotation axis, and to obtain the adhesive release force effect of the invention.

[0048]

As described above, according to the present invention, by making the contact holding zone of the head slider close to the vicinity of the disk rotation axis, the radius from the disk rotation center to the point of action of the head / disk detackifying force is reduced. Therefore, even with a small-sized and low-power-consumption magnetic disk device having a small starting torque of the disk spindle motor, it is possible to obtain a sufficient head / disk adhesion releasing force at the time of starting the disk rotation. At this time, when the head slider support spring is deformed by a predetermined amount or more,
The amount of deformation of the head slider support spring is limited to a predetermined value or less by the means for contacting the head slider, and plastic deformation or damage of the head slider support spring is prevented.

[Brief description of drawings]

FIG. 1 is a plan view of a magnetic disk device showing a head slider position and a disk surface at startup according to an embodiment of the present invention.

FIG. 2 is a plan view of a magnetic disk device showing a head slider position and a disk surface at the start of flying according to an embodiment of the present invention.

FIG. 3 is a graph showing a relationship between a head slider adhesion position radius and a maximum adhesion release force according to an embodiment of the present invention.

FIG. 4 is a graph showing start control of a head slider position radius and elapsed time according to an embodiment of the present invention.

FIG. 5 is a graph showing startup control of disk rotation speed and elapsed time according to an embodiment of the present invention.

FIG. 6 is a plan view showing a head suspension portion of a magnetic disk device according to an embodiment of the present invention.

FIG. 7 is a plan view of a head suspension portion showing a state when an adhesion releasing force is applied from the state of FIG.

FIG. 8 is a simplified cross-sectional view of a magnetic disk device when a head slider is held and activated according to an embodiment of the present invention.

[Explanation of symbols]

 101 Magnetic Disk Unit 102 Actuator 103 Head Suspension 104 Head Slider 105 Disk 106 Data Zone 107 Flying and Landing Sliding Zone 108 Moving Sliding Zone 109 Contact Holding Zone 110 Adhesion Release Force F 111 Disk Rotating Axis 112 Head Slider Sliding Trajectory 121 Load Arm 122 Gimbal 123 Head slider core part 124 Stopper 125 Head signal thin wire 126 Gimbal spot welding point 131 Disc rotation center concave part 132 Spindle motor 133 Spindle motor rotation center convex part 134 Adhesive layer 135 Circuit board 136 Circuit parts

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroaki Ota 2880, Kozu, Odawara, Kanagawa Stock Company Hitachi Storage Systems Division (72) Inventor Yusuke Miyamoto 2880, Kozu, Odawara, Kanagawa Hitachi Storage System Division (72) Inventor Kojiro Hayashi 2880 Kozu, Odawara-shi, Kanagawa Stock Company Hitachi Storage Systems Division (72) Inventor Atsushi Ito 2880 Kozu, Odawara, Kanagawa Hitachi Storage Systems Division

Claims (6)

[Claims] 1. In a magnetic disk device of the type in which a head slider is held in contact with the disk surface on the inner peripheral side when the disk rotation is stopped, the radius of the contact holding zone on the disk surface is set by the head slider on the disk surface. A magnetic disk drive characterized in that the radius of the zone that slides when flying or landing is substantially smaller than the radius of the zone. 2. In a magnetic disk device of the type in which a head slider is held in contact with an inner peripheral side disk surface when the disk rotation is stopped, the radius of the contact holding zone on the disk surface is the data recording on the disk surface. A magnetic disk drive characterized by being substantially smaller than the radius of the zone. 3. The magnetic disk device according to claim 1, wherein the contact holding zone on the disk surface is near the disk rotation axis. 4. A magnetic disk device of the type in which a head slider is held in contact with the inner peripheral disk surface when the disk rotation is stopped, and the head slider is kept in contact with the disk surface when the disk rotation is started. First, after the disk is started to rotate to a low speed rotation state, the head slider is moved toward the outer peripheral side on the disk surface to shift the disk to a high speed rotation state. Characteristic magnetic disk device. 5. The disk according to claim 1, wherein a disk having no through hole at the center of rotation is attached to a spindle motor, and the contact holding zone on the disk surface is near the disk rotation axis. A magnetic disk device characterized in that 6. The head according to claim 1, wherein when the head slider receives a force from the disk surface when the disk rotation is started and the head slider support spring is deformed by a predetermined amount or more. A magnetic disk device comprising means for contacting a slider and limiting a deformation amount of a head slider support spring to a predetermined amount or less to prevent plastic deformation or damage of the head slider support spring.