JP2003051165A - Inertia latch mechanism of actuator and disk device provided with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inertia latch mechanism of an actuator stably operated in any situations and capable of reducing a joggling sound, and a disk device provided with the mechanism. SOLUTION: This inertia latch mechanism for latching a head actuator to a retreating position when external force is applied, is provided with a latch arm engaged with the engaging projection protruded from the head actuator to latch the head actuator to the retreating position, and an inertia arm 52 for rotating the latch arm to its latching position when impact is generated. The inertia arm 52 has a bearing recess 52a for receiving a rotary shaft 54, and a top yoke 40 is disposed in a side opposite the recess to regulate pulling- out from the rotary shaft 54. On the surface 40a of the top yoke 40 opposite the inertia arm 52, a projection 71 positioned above the rotary shaft 54 is arranged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inertial latch mechanism for an actuator and a disk device equipped with this inertial latch mechanism.

[0002]

2. Description of the Related Art In recent years, magnetic disk devices, for example, have been widely used as large-capacity disk devices in electronic equipment such as personal computers. In general,
The magnetic disk device includes a magnetic disk disposed in a case, a spindle motor that supports and rotates the magnetic disk, a head actuator that supports a magnetic head,
Voice coil motor that drives the head actuator,
It is equipped with a substrate unit and the like.

In recent years, portable small personal computers have become widespread, and the magnetic disk device mounted on this type of personal computer is required to have improved reliability against shock or the like when being carried.

Therefore, a mechanism provided with a ramp load mechanism has been proposed as a mechanism for holding the magnetic head when the magnetic disk device is not operating. This ramp loading mechanism
A ramp provided outside the magnetic disk is provided, and when the magnetic disk device is not operating, the head actuator is rotated to a retracted position located on the outer circumference of the magnetic disk, and the suspension rides on the ramp. As a result, the magnetic head is held at the retracted position separated from the surface of the magnetic disk, and the collision with the magnetic disk is prevented when an impact is received.

Further, as this type of magnetic disk device,
In order to further improve impact resistance, a device provided with an inertial latch mechanism has been proposed. This inertia latch mechanism, when not in operation, when a shock is applied to the magnetic disk device,
The head actuator is engaged and its rotation is restricted, and the head actuator is held at the retracted position.

More specifically, the inertia latch mechanism has a center of gravity at a position deviated from the center of rotation so that the inertia arm rotates in both forward and reverse directions due to impact acceleration from the outside, and is biased by the rotation of the inertia arm. Has a latch arm that rotates in one direction, and when a shock occurs when not operating, the latch claw protruding from the tip of the rotation of the latch arm engages with the head actuator to move the head actuator to the retracted position. Hold.

[0007]

In the inertia latch mechanism having the above-described structure, each arm is attached with a play with respect to its rotating shaft in order to enhance the responsiveness of the inertia arm and the latch arm. It is attached with a degree of freedom in the axial direction. Therefore, each arm vibrates in the axial direction due to the impact from the outside, and the vibration characteristics of the peripheral members are deteriorated, or the impact sound caused by the collision of each arm with the peripheral members (joggling sound).
There was a problem that caused.

In particular, with respect to the inertia arm having a relatively large mass, the problem of the joggling sound is great, and when the user hears the joggling sound when shaking the device, he or she may misunderstand that it is a malfunction and make a claim. there were.
For this reason, it is required to suppress the jog sound of the inertia arm to a low level.

For example, as shown in the rotating structure in FIG. 7, a conventional inertia arm 101 has a rotating shaft 10
2 has a through hole 101a through which the rotary shaft 102 is passed and the shoulder portion 1 of the rotary shaft 102 is inserted.
02a is retained and retained. Then, in order to prevent the inertia arm 101 from coming off the rotary shaft 102,
A lid 103 is provided to cover the tip of the rotating shaft 102. Further, two hemispherical projections 104, 105 are provided so as to project from the inside of the lid 103 in a positional relationship of sandwiching the rotary shaft 102,
The gap between the lid 103 and the inertia arm 101 is made small. As a result, the amplitude of vibration along the axial direction of the inertia arm 101 is reduced.

However, according to the above configuration, when the device is turned upside down, the protrusions 104 and 105 of the lid 103 come into contact with the inertia arm 101 at two points, and a moment is generated by the contact, causing the inertia arm 101 to rotate. There was a problem that hindered.

The present invention has been made in view of the above points, and an object thereof is to stably operate in any situation,
An object of the present invention is to provide an inertial latch mechanism of an actuator capable of reducing joggling noise, and a disk device equipped with this inertial latch mechanism.

[0012]

In order to achieve the above object, an inertial latch mechanism of an actuator of the present invention supports a head movably with respect to a disk-shaped recording medium and has a predetermined retracted position and An actuator movable to an information processing position on a recording medium and latching the actuator at the predetermined retracted position, the latch position engaging the actuator and latching the actuator at the retracted position; It has a latch arm rotatably provided between the release position to release the latch and to release the latch, and a recess for receiving the rotation shaft of the latch arm. The latch arm rotates around the rotation shaft when receiving an external force. By doing so, the inertia arm for rotating the latch member from the release position to the latch position and the inertia arm on the opposite side of the recess of the inertia arm A restricting member that is provided apart from the inertia arm and restricts the inertia arm from coming off from the rotating shaft, and a single protrusion on the rotating shaft that protrudes from one of the inertia arm and the restricting member. , Are provided.

According to the above invention, when the inertia arm vibrates in the direction of the rotation axis, the inertia arm and the regulating member come into contact with each other by the only protrusion provided on the rotation axis, so that the amplitude of the inertia arm can be reduced. The generation of joggles can be suppressed, and even when the device is inverted, no moment is generated by the contact of the protrusions,
The inertia arm can be rotated with high responsiveness, and the inertia latch mechanism can be operated stably.

Further, the inertia latch mechanism of the actuator of the present invention movably supports the head with respect to the disk-shaped recording medium, and is movable to a predetermined retracted position and the information processing position on the recording medium. An actuator for latching the actuator to the predetermined retracted position, having a recess for receiving the rotation shaft, and engaging the actuator to latch the actuator in the retracted position; By releasing the latch arm to release the latch and the latch arm that is pivotally provided between the latch arm and pivoting when an external force is applied,
An inertia arm for rotating the latch member from the release position to the latch position about the rotation axis, and an arm provided on the side opposite to the recess of the latch arm and spaced from the latch arm. A restricting member for restricting removal from the rotating shaft and a unique protrusion protruding from either the latch arm or the restricting member on the rotating shaft are provided.

According to the above invention, when the latch arm vibrates in the direction of the rotating shaft, the latch arm and the regulating member come into contact with each other by the only protrusion provided on the rotating shaft. Therefore, the amplitude of the latch arm can be reduced. The generation of joggles can be suppressed, and even when the device is turned upside down, the moment caused by the contact of the protrusion is not generated, the latch arm can be rotated with high responsiveness, and the inertia latch mechanism can be stabilized. Can work.

Further, in the disk device of the present invention, a disk-shaped recording medium, driving means for supporting and rotating the recording medium, a head for performing information processing on the recording medium, and the head for recording the information. An actuator that is movably supported with respect to the medium and is movable to a predetermined retracted position located on the outer peripheral side of the recording medium and an information processing position on the recording medium, and this actuator is located at the retracted position. An inertial latch mechanism for latching the actuator to the retracted position when an external force is applied while moving, and the inertial latch mechanism comprises:
A latch arm rotatably provided between a latch position that engages with the actuator and latches the actuator in the retracted position and a release position that is separated from the actuator and releases the latch, and its rotation. An inertia arm that has a recess for receiving the shaft and that rotates the latch member from the release position to the latch position by rotating about the rotation shaft when receiving an external force, and the inertia arm described above. A restricting member that is provided on the opposite side of the recess from the inertia arm and that restricts the inertia arm from coming off from the rotating shaft; and a restricting member that protrudes from the inertia arm or the restricting member on the rotating shaft. It is equipped with the only protrusion.

Further, in the disk device of the present invention, a disk-shaped recording medium, driving means for supporting and rotating the recording medium, a head for performing information processing on the recording medium, and the head for recording the information. An actuator that is movably supported with respect to the medium and is movable to a predetermined retracted position located on the outer peripheral side of the recording medium and an information processing position on the recording medium, and this actuator is located at the retracted position. An inertial latch mechanism for latching the actuator to the retracted position when an external force is received while the actuator is moving, the inertial latch mechanism having a recess for receiving the rotation shaft thereof, and engaging with the actuator. And the latch position where the actuator is latched to the retracted position and the release where the actuator is separated from the actuator and the latch is released. A location, a latch arm provided rotatably between, by rotating when subjected to external forces,
An inertia arm for rotating the latch member from the release position to the latch position about the rotation axis, and an arm provided on the side opposite to the recess of the latch arm and spaced from the latch arm. A restricting member for restricting removal from the rotating shaft and a unique protrusion protruding from either the latch arm or the restricting member on the rotating shaft are provided.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments in which the present invention is applied to a magnetic disk device will be described below in detail with reference to the drawings.

FIG. 1 is a perspective view showing the external appearance of a magnetic disk device 1 according to this embodiment. Also, FIG.
FIG. 3 schematically shows a plan view of the head actuator 18 (actuator) incorporated in the magnetic disk device 1 and the inertia latch mechanism 50.

As shown in FIG. 1, a magnetic disk device 1
Has a rectangular box-shaped case 10 having an open top surface and a top cover (not shown) that is screwed to the case with a plurality of screws to close the upper end opening of the case.

In the case 10, two magnetic disks 16 as recording media, a spindle motor 12 as a driving means for supporting and rotating the magnetic disks 16,
A plurality of magnetic heads 32 for writing and reading information to and from the magnetic disk 16, and these magnetic heads 32
Head actuator 18 that movably supports the magnetic disk 16 and a voice coil motor that rotates and positions the head actuator 18 (hereinafter referred to as VCM).
20) (see FIG. 2), a ramp load mechanism 24 and a head actuator 18 for holding the magnetic head 32 at a position separated from the magnetic disk 16 when the magnetic head 32 moves to the retracted position on the outermost periphery of the magnetic disk 16. An inertial latch mechanism 50 (see FIG. 2) for holding the substrate in the retracted position, a substrate unit 60 having a head IC, and the like are stored.

The magnetic disk 16 has a diameter of 65 mm (2.
5 inches) and has magnetic recording layers on the upper and lower surfaces. The magnetic disk 16 is the spindle motor 1
It is coaxially fitted to the second hub 14 and is held by a clamp spring. And the magnetic disk 1
6 is rotated by a spindle motor 12 at a predetermined speed.

As shown in detail in FIG. 2, the head actuator 18 has a bearing assembly 26 fixed on the bottom wall of the case 10, and mounted on and extending from the bearing assembly 26. Two arms 28 (only one shown), and a support frame 34 attached to the bearing assembly 26 and extending in a direction opposite to the arms 28,
Is equipped with. An elastically deformable elongated plate-shaped suspension 30 is fixed to the extending end of each arm 28, and a magnetic head 32 is attached to the tip of the suspension 30 via a gimbal portion (not shown).

The head actuator 18 is rotatable about the bearing assembly 26, and the two pairs of magnetic heads 32 supported by the two arms 28 via the suspensions 30 include the arms 28 and the suspension 3.
It is possible to rotate integrally with 0 and move to any information processing position on the magnetic disk 16 and a retracted position described later. Each magnetic head 32 is electrically connected to the board unit 60 via a flexible cable 62.

On the other hand, the support frame 34 of the head actuator 18 is made of synthetic resin, and the voice coil 36 is integrally embedded in the support frame 34. The voice coil 36 is located between a pair of yokes 40 (only one of which is shown) fixed on the bottom wall of the case 10 and constitutes the VCM 20 together with these yokes. Then, by energizing the voice coil 36,
The head actuator 18 rotates to move and position the magnetic head 32 on a desired track of the magnetic disk 16.

The ramp load mechanism 24 is provided on the bottom wall of the case 10 and is located on the outer peripheral side of the magnetic disk 16. When the head actuator 18 is moved to the retracted position, the ramp load mechanism 24 projects from the two suspensions 30, respectively. Guide and support the formed tab 31. A stopper block 38 is provided near the support frame 34 of the head actuator 18 to prevent the head actuator 18 from further rotating beyond its retracted position.

As described above, when the head actuator 18 is set in the retracted position and is not in operation, when the external force such as a shock is applied to the magnetic disk device 1, the inertia latch mechanism 50 is operated to operate the head actuator 18. It is designed to be latched in the retracted position. The inertia latch mechanism 50 includes an engagement protrusion 37 that protrudes outward from the support frame 34 of the head actuator 18, that is, in the radial direction with respect to the bearing assembly 26. Further, the inertia latch mechanism 50 is used for the head actuator 18
Latch arm 5 provided near the support frame 34 of the
1 and inertia arm 52.

The latch arm 51 is rotatably supported around a rotary shaft 53 extending in a direction (direction of the plane of the drawing) substantially orthogonal to the surface on which the head actuator 18 rotates. In other words, the latch arm 51 has the rotating shaft 5 on one side thereof.
3 has a bearing recess 51a that receives the tip of the bearing 3. Also,
The latch arm 51 has a latch claw 51 b located on the engagement projection 37 side of the support frame 34 with respect to the rotation shaft 53.
And a hook 51c located on the opposite side of the rotation shaft 53 from the latch pawl 51b. The distance between the rotating shaft 53 and the latch claw 51b is formed sufficiently longer than the distance between the rotating shaft 53 and the hook 51c.

The latch arm 51 has a rotary shaft 53.
Is rotatable around a release position shown in the figure and a latch position where the latch claw 51b engages with the engagement projection 37. That is, the latch arm 51 is configured so that when an external force such as an impact is applied to the case 10, the inertia arm 5 described later is used.
By the action of 2, the latch position is rotated from the release position to the latch position, and the latch claw 51b is engaged with the engaging protrusion 3 of the head actuator 18.
7 and latches the head actuator 18 in the retracted position.

On the other hand, the inertia arm 52 is rotatably supported around a rotary shaft 54 extending in a direction (direction of the paper surface) substantially orthogonal to the surface on which the head actuator 18 rotates. In other words, the inertia arm 52 has a bearing recess 52a that receives the tip of the rotary shaft 54 on one side thereof. The inertia arm 52 is arranged so as to partially overlap the latch arm 51 so as to be adjacent and opposed to the head actuator 18 at a position where the latch arm 51 is sandwiched. In addition, inertia arm 5
The second rotation shaft 54 is located near the one end of the inertia arm 52 while being biased, and also the latch arm 51.
The rotary shaft 53 is sufficiently separated from the rotary shaft 53.

At the other end of the inertia arm 52 which is separated from the rotary shaft 54, the hook 5 of the latch arm 51 is located between the latch arm 51 and the head actuator 18.
A pin 55 engageable with 1c is provided so as to project toward the latch arm 51. Further, a pin 56 is provided so as to project toward the latch arm 51 at an intermediate portion between the rotary shaft 54 and the pin 55 of the inertia arm 52. The pin 56 faces the latch arm 51 on the opposite side of the head actuator 18, and is located on the opposite side of the pin 55 with respect to the rotary shaft 53 of the latch arm 51.

When an external force such as an impact is applied to the case 10, the inertia arm 52 is rotated around the rotary shaft 54 in the clockwise direction or the counterclockwise direction according to the acting direction of the external force, and the pins 55, 56 are provided. The latch arm 51 is pressed via. For example, when the inertia arm 52 rotates clockwise around the rotation shaft 54, the pin 56 presses the latch arm 51, and the latch arm 51 rotates counterclockwise. When the inertia arm 52 rotates counterclockwise around the rotation axis 54, the pin 55 moves the latch arm 51.
, The latch arm 51 rotates counterclockwise. In this way, when the latch arm 51 rotates counterclockwise, the latch claw 51b engages with the engaging protrusion 37 of the head actuator 18, and the head actuator 18 is latched at the retracted position.

According to the magnetic disk device 1 constructed as described above, the magnetic head 32 is moved onto a desired track of the magnetic disk 16 by rotating the head actuator 18 by the VCM 20 during normal operation. , Record or reproduce information on a magnetic disk.

Further, as shown in FIG. 1, when the head actuator 18 is rotated by the VCM 20 from the operating position toward the retracted position shown in FIG. Magnetic disk 1
It moves from the inner circumference side of 6 toward the outermost circumference. When the magnetic head 32 moves to the vicinity of the outer peripheral edge of the magnetic disk 16, the tabs 31 extending from the respective suspensions 30 project outward from the outer peripheral edge of the magnetic disk 16, and the magnetic head 32 is moved by the ramp load mechanism 24. It is unloaded in a state of being separated from the surface of the magnetic disk 16.

When the magnetic disk device 1 is in a non-operating state, for example, when a large external force such as an external impact acts on the case 10, the inertial latch mechanism 50 is caused by the inertial force.
Operates and latches the head actuator 18 as described above. This completely prevents the head actuator 18 from rotating from the retracted position to the magnetic disk 16 side.

When the external force acting on the magnetic disk device 1 is released, the inertia latch mechanism 50 is returned to the latch release state by the return means (not shown), and the latch arm 51 is maintained at the release position shown in FIG. It That is, the inertia latch mechanism 50 is used in the magnetic disk device 1
It operates only when an external force is applied to.

Next, a rotating structure according to the first embodiment of the present invention for rotatably supporting the inertia arm 52 will be described with reference to FIG. Although the rotating structure of the inertia arm 52 will be described here, it is assumed that the latch arm 51 also has a similar rotating structure.

The inertia arm 52 has a rotating shaft 54.
Has a circular bearing recess 52a for receiving the tip of the. The inertia arm 52 set on the rotary shaft 54 via the bearing recess 52a is contacted and supported by the shoulder portion 54a having a large diameter. That is, the tip of the rotary shaft 54 and the bearing recess 52a do not come into contact with each other. In addition, the inertia arm 52 is provided at a position separated from the inertia arm 52 on the side opposite to the bearing recess 52a of the inertia arm 52.
The above-described top yoke 40 that functions as a restricting member for restricting the slipping off of the rotary shaft 54 from the rotating shaft 54 is provided. The top yoke 40 also functions as a regulating member on the side of the latch arm 51, and is fixedly attached to the case 10 side by a magnet in a non-contact state with the arms 51 and 52.

Inertia arm 52 of top yoke 40
A substantially hemispherical protrusion 71 is integrally provided on the surface 40a facing the. The protrusion 71 is positioned and provided on the extension line of the rotating shaft 54 so as to reduce the gap between the inertia arm 52 and the top yoke 40 as much as possible. That is, the protrusion 71 functions so that the inertia arm 52 and the top yoke 40 can make point contact with each other on the rotating shaft 54.

For example, when the inertia arm 52 vibrates in the direction of the rotary shaft 54 by an external force, the inertia arm 52
Is restricted from moving between the shoulder 54a of the rotary shaft 54 and the apex of the protrusion 71. Therefore, the amplitude of the inertia arm 52 can be reduced by reducing the distance between the apex of the protrusion 71 and the inertia arm 52. This allows
It is possible to reduce the impact sound (hereinafter, referred to as a jog sound) when the inertia arm 52 collides with a peripheral member due to vibration.

Further, for example, when the device is inverted with the top yoke 40 down, the inertia arm 52 makes point contact with the apex of the protrusion 71 on the rotating shaft 54, so that the protrusion 71 remains even when the device is inverted. The inertia arm 52 can be rotated as usual without generating a moment due to the contact of. In other words, if the rotating structure of the present embodiment is adopted, under any circumstances,
The inertia latch mechanism 50 can be operated stably.

FIG. 4 shows the rotating structure of the inertia arm 52 according to the second embodiment of the present invention. In this embodiment, the inertia arm 52 is made of a plastic material at least near the center of rotation thereof, and the protrusion 72 is integrally provided on the surface 521 of the inertia arm 52 facing the top yoke 40. This protrusion 72
Functions similarly to the protrusion 71 of the first embodiment described above.

In this embodiment as well, the same effects as those of the first embodiment described above can be obtained, and the protrusion 72 of the inertia arm 52 is formed of a plastic material so that the top yoke 40 and the top yoke 40 can be formed. It is possible to further reduce the joggling sound generated by the collision between the two.

FIG. 5 shows the rotating structure of the inertia arm 52 according to the third embodiment of the present invention. In this embodiment, instead of the top yoke 40, a spring member 74 for pressing the projection 73 is provided on the surface 521 of the inertia arm 52. The spring member 74 having the projection 73 at its tip is formed of a stretchable plastic material such as polyacetal. In this structure, the apex of the protrusion 73 is always in point contact with the surface 521 of the inertia arm 52 on the rotating shaft 54.

In this embodiment as well, the same effect as that of the first embodiment described above can be obtained, and the protrusion 73 is constantly pressed against the inertia arm 52 on the rotary shaft 54, so that Can absorb vibration in the axial direction. As a result, the joggling sound caused by the fluttering of the inertia arm 52 can be further reduced.

FIG. 6 shows the rotating structure of the inertia arm 52 according to the fourth embodiment of the present invention. In this embodiment, a protrusion 75 having a spring structure is adopted as the protrusion 72 of the second embodiment shown in FIG. That is, by making the wall thickness of the protrusion 75 relatively thin,
It is elastically deformable. Then, the apex of the protrusion 75 is positioned and arranged so as to make point contact with the surface 40 a of the top yoke 40 on the rotating shaft 54.

Also in this embodiment, the same effect as that of the above-described second embodiment can be obtained, and since the protrusion 75 itself is elastically deformable, the apex of the protrusion 75 is brought into contact with the top yoke 40. Therefore, the joggling sound caused by the flapping of the inertia arm 52 can be further reduced.

As described above, according to the present invention, the inertia arm 52 has the bearing recess 52a for receiving the rotary shaft 54, and the regulating member such as the top yoke 40 is provided on the opposite side of the recess with a gap. A single protrusion is provided between the regulating member and the inertia arm 52 so that they can be point-contacted on the rotary shaft 54. Therefore, even when the device is inverted, no moment is generated due to the contact of the protrusions, the inertia arm 52 can be stably rotated, and the inertia latch mechanism 50 can be stably operated. Further, by providing the protrusion between the inertia arm and the regulation member, the gap between the two can be reduced, vibration in the axial direction of the inertia arm 52 can be suppressed, and the joggling sound caused by the flapping of the inertia arm 52 can be suppressed. Can be made smaller.

The present invention is not limited to the above-described embodiments, but can be variously modified within the scope of the present invention. For example, the materials of the inertia arm 52 can be easily changed by appropriately combining the above-described first to fourth embodiments.

Further, although the rotating structure of the inertia arm 52 has been described in the above embodiment, it is also effective to adopt the rotating structure of the present invention in the latch arm 51.

Besides, the present invention is applicable not only to the magnetic disk device but also to other disk devices such as an optical disk device.

[0052]

As described in detail above, according to the present invention, the inertial latch mechanism of the actuator which can stably operate in any situation and can reduce the joggling noise,
Further, it is possible to provide a disk device provided with this inertial latch mechanism.

[Brief description of drawings]

FIG. 1 is a perspective view showing a schematic configuration of a magnetic disk device according to an embodiment of the present invention.

FIG. 2 is a plan view showing a head actuator and an inertia latch mechanism incorporated in the magnetic disk device of FIG.

FIG. 3 is a partial cross-sectional view showing a partially enlarged rotary structure of the inertia arm of the inertia latch mechanism of FIG. 2 according to the first embodiment.

FIG. 4 is a partial cross-sectional view showing a partially enlarged rotary structure of an inertia arm of the inertia latch mechanism of FIG. 2 according to a second embodiment.

5 is a partial cross-sectional view showing a partially enlarged rotary structure of an inertia arm of the inertia latch mechanism of FIG. 2 according to a third embodiment.

6 is a partial cross-sectional view showing a partially enlarged rotary structure of an inertia arm of the inertia latch mechanism of FIG. 2 according to a fourth embodiment.

FIG. 7 is a partial cross-sectional view partially enlarged showing a rotating structure of an inertia arm of a conventional inertia latch mechanism.

[Explanation of symbols]

1 ... Magnetic disk device, 10 ... Case, 12 ... Spindle motor, 16 ... magnetic disk, 18 ... Head actuator, 20 ... Voice coil motor, 24 ... Lamp load mechanism, 32 ... magnetic head, 37 ... engagement protrusion, 40 ... Top yoke, 50 ... inertia latch mechanism, 51 ... a latch arm, 52 ... inertia arm, 51a, 52a ... Bearing recess, 53, 54 ... rotary shaft, 71, 72, 73, 75 ... Protrusions.

Claims (12)

[Claims] 1. An actuator, which supports a head movably with respect to a disk-shaped recording medium and is movable to a predetermined retracted position and an information processing position on the recording medium, to the predetermined retracted position. An inertial latch mechanism for latching, which is rotatably provided between a latching position for engaging the actuator and latching the actuator at a retracted position and a releasing position for separating the actuator and releasing the latching. Latch arm and a recess for receiving the rotation shaft thereof, and an inertia for rotating the latch member from the release position to the latch position by rotating about the rotation shaft when receiving an external force. An arm and a side of the inertia arm opposite to the recess, spaced apart from the inertia arm. An inertial latch mechanism comprising: a restricting member that restricts slipping out of the rotating shaft; and a sole projection that is provided on the rotating shaft so as to project from one of the inertia arm and the restricting member. 2. The projection has a tip capable of making point contact on the rotary shaft with respect to one of the inertia arm and the regulating member when the inertia arm moves in the rotary shaft direction. The inertia latch mechanism according to claim 1. 3. The inertia according to claim 1, wherein the protrusion is formed by an elastic member whose tip is in constant contact with either one of the inertia arm and the regulating member on the rotation shaft. Latch mechanism. 4. An actuator, which supports a head movably with respect to a disk-shaped recording medium and is movable to a predetermined retreat position and an information processing position on the recording medium, to the predetermined retreat position. An inertial latch mechanism for latching, which has a recess for receiving its rotation shaft, and which is engaged with the actuator to latch the actuator in the retracted position, and release for releasing the latch apart from the actuator. A latch arm rotatably provided between the position and an inertia position for rotating the latch member from the release position to the latch position about the rotation shaft by rotating when receiving an external force. The arm is provided on the opposite side of the recess of the latch arm from the latch arm so as to prevent the latch arm from coming off the rotary shaft. An inertial latch mechanism comprising: a restricting member that controls the rotating shaft; and a single protrusion that is provided on the rotating shaft so as to protrude from one of the latch arm and the restricting member. 5. The projection has a tip capable of making point contact on the rotary shaft with respect to one of the latch arm and the regulating member when the latch arm moves in the rotary shaft direction. The inertia latch mechanism according to claim 4. 6. The inertia according to claim 4, wherein the protrusion is formed by an elastic member whose tip is in constant contact with either one of the latch arm and the regulating member on the rotation shaft. Latch mechanism. 7. A disk-shaped recording medium, a driving means for supporting and rotating the recording medium, a head for performing information processing on the recording medium, and a head for moving the head with respect to the recording medium. An actuator that supports and is movable to a predetermined retracted position located on the outer peripheral side of the recording medium and an information processing position on the recording medium, and an external force while the actuator is moving to the retracted position. An inertial latch mechanism for latching the actuator to the retracted position when receiving the actuator, the inertial latch mechanism engaging the actuator and latching the actuator in the retracted position; and the actuator. And a latch arm that is rotatable between the release position and the release position where the latch is released. An inertia arm that has a recess for receiving the shaft and that rotates the latch member from the release position to the latch position by rotating about the rotation shaft when receiving an external force, and the inertia arm described above. A restricting member that is provided on the opposite side of the recess from the inertia arm and restricts the inertia arm from coming off from the rotary shaft, and a protruding member on the rotary shaft from either the inertia arm or the restricting member. A disk device that is equipped with the only protrusion that is provided. 8. The projection has a tip capable of making point contact on the rotary shaft with respect to one of the inertia arm and the regulating member when the inertia arm moves in the rotary shaft direction. The disk device according to claim 7. 9. The disk according to claim 7, wherein the protrusion is formed by an elastic member whose tip is in constant contact with either one of the inertia arm and the regulating member on the rotation shaft. apparatus. 10. A disk-shaped recording medium, a driving means for supporting and rotating the recording medium, a head for performing information processing on the recording medium, and a head movably with respect to the recording medium. An actuator that supports and is movable to a predetermined retracted position located on the outer peripheral side of the recording medium and an information processing position on the recording medium, and an external force while the actuator is moving to the retracted position. An inertia latch mechanism for latching the actuator to the retracted position when receiving the actuator, the inertia latch mechanism having a recess for receiving its rotation shaft, and engaging the actuator to retract the actuator. Between the latch position where it is latched at the position and the release position where it is released from the actuator to release the latch. And a recessed portion of the latch arm, and an inertia arm for rotating the latch member about the rotation shaft from the release position to the latch position by rotating the latch arm when an external force is applied. A restricting member that is provided on the opposite side to the latch arm and is separated from the latch arm, and restricts the latch arm from coming off from the rotating shaft; A disk device that is equipped with a unique protrusion and. 11. The projection has a tip capable of making point contact on the rotation shaft with respect to one of the latch arm and the regulating member when the latch arm moves in the rotation shaft direction. The disk device according to claim 10. 12. The disk according to claim 10, wherein the projection is formed by an elastic member whose tip is always in contact with one of the latch arm and the regulating member on the rotation shaft. apparatus.