Dynamic magnetic information storage or retrieval – Head mounting – Disk record
Reexamination Certificate
1999-11-19
2001-05-15
Davis, David (Department: 2652)
Dynamic magnetic information storage or retrieval
Head mounting
Disk record
Reexamination Certificate
active
06233120
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to a magnetic disk device as one of storage devices of computers. More specifically, this invention relates to a magnetic disk device having a positioning structure suitable for reducing the size and the thickness of a magnetic disk device, for achieving a large storage capacity and a high recording density and for improving an information processing speed.
JP-A-8-45205 (hereinafter called the “first related art example”) and JP-A-5-325459 (hereinafter called the “second related art example”) describe a positioning mechanism for accomplishing the reduction of the size and the thickness of the device, a large capacity, high recording density and a high information processing speed. The first and second related art examples improve positioning accuracy by restraining the vibration occurring in the magnetic disk device.
The first related art example prevents the vibration of a voice coil motor resulting from the movement of a carriage from being transmitted to a base by fixing the voice coil motor and the base through viscoelastic members, or the like.
The second related art example restricts the residual vibration by a spring arm at the time of seek by providing a vibration absorption member to the spring arm.
Because it has been customary to package the magnetic disk device into notebook type personal computers, the reduction of its size and thickness and a large storage capacity and a high recording density of the disk device have been required in the past. Because the notebook type personal computers are mainly of the type which incorporate a battery and can be operated even in the absence of an alternating current outlet, low power consumption is another essential requisite. In addition, reliability and low price of the device and a higher information processing speed are required naturally.
To satisfy these requirements, a positioning mechanism of the magnetic disk device must reduce as much as possible a relative position error between the disk and the head. Factors of the position error include the vibration of the head and a carriage swinging portion for supporting the head and the vibration of the disk and a spindle motor rotation portion for supporting the disk.
If the amplitude of the vibration is great when the head reads out the information recorded circumferentially on the disk surface, the head reads also the information adjacent to the target position in the radial direction. Therefore, the space of the information in the radial direction must be increased. However, a large capacity cannot be achieved in this case, and the reduction of both size and thickness cannot be attained.
The vibration of the head increases the number of times of repetition of correction of the head position in positioning control and requires a long settling time before positioning is made correctly to the target position. Therefore, the vibration of the head also impedes a higher information processing speed of the magnetic disk device.
To use the full surface of the mounted disk, a head arm of a carriage includes a portion at which two heads are mounted via suspensions or spring arms as shown in
FIG. 6 and a
portion at which one head is mounted via a suspension as shown in FIG.
7
. The portion having one head mounted via a suspension thereto involves the problem that the vibration (amplitude) is great.
The systems described in the first and second related art examples have been examined as means for solving the problem but they are not entirely satisfactory for restraining the vibration (amplitude) of the portion at which one head is mounted via a suspension.
SUMMARY OF THE INVENTION
In view of the problem of the related art technologies described above, an object of the present invention is to provide a magnetic disk device equipped with a positioning mechanism suitable for restraining the vibration (amplitude) of a portion at which one head is mounted via a suspension, for not increasing the size and the thickness of the device, for achieving a large storage capacity and a high recording density and for improving an information processing speed.
The magnetic disk device according to a first aspect of the present invention is applied to a magnetic disk device including a magnetic disk for recording information, a spindle motor for holding and rotating the magnetic disk, a head assembly including a head, gimbals and equipped with a slider and a suspension for recording and reproducing information to and from the magnetic disk, a head arm portion for fixing the heads, a carriage for moving the heads on a disk surface in a radial direction and positioning them and a head disk assembly including a base and a cover for holding these members and closing them off from external air. This magnetic disk device has the following features.
A member having a natural frequency equal to that of the head under the packaged state is disposed on the opposite surface of a head arm to which one head is mounted via a suspension.
The magnetic disk device according to a second aspect of the present invention has the following feature. In the first aspect of a invention described above, the profile of the member described above, which is projected in a direction perpendicular to the magnetic disk-surface, is similar to the profile of the head and suspension projected in the direction perpendicular to the magnetic disk surface, or does not swell out from the profile of the head and suspension projected in the direction perpendicular to the magnetic disk surface.
The magnetic disk device according to a third aspect of the present invention has the following feature. The member described above is mounted to the head arm by the same means as that of the head.
Incidentally, a member which generates the vibration equal to that of the arm having two heads mounted thereto via suspensions may be disposed on the opposite surface of the head arm having one head mounted via a suspension thereto. Furthermore, the second and third aspect features described above may likewise be applied to the member disposed on the opposite surface of the head arm having one head mounted via a suspension thereto so as to generate the vibration similar to that of the arm having two heads mounted thereto.
REFERENCES:
patent: 5305169 (1994-04-01), Anderson et al.
patent: 5995327 (1999-11-01), Hanada et al.
patent: 2-292784 (1990-12-01), None
patent: 5-325459 (1993-12-01), None
patent: 6-124424 (1994-05-01), None
patent: 8-45205 (1996-02-01), None
Hanada Kazuyoshi
Honchi Masayuki
Iami Satomitsu
Okazaki Toshihisa
Takagi Hideyuki
Antonelli Terry Stout & Kraus LLP
Davis David
Hitachi , Ltd.
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