The present invention is related to a head support mechanism that is arranged in a disk device such as a magnetic disk or the like that is used as a memory device of computers, and more particularly to a head support mechanism best suited for achieving high recording density of data in the magnetic disk device. In recent years a recording density of a magnetic disk that is used for a magnetic disk device has been remarkably and progressively increasing. A magnetic head that is used for recording data to and/or for reproducing data of a magnetic disk is normally arranged at a slider, and the slider at which the magnetic head is mounted is supported by a head support mechanism arranged in the magnetic disk device. The head support mechanism is arranged at a head support arm, and the head support arm is arranged such as to be revolvable by a voice coil motor (VCM).
In order to record data to a magnetic disk with even higher density, it is necessary to position the magnetic head with respect to the magnetic disk with a higher degree of precision. In order to achieve the precision, a head support mechanism for positioning a magnetic head with high precision has already been proposed (see JP Laid-Open Patent Publication No. H2-227886).
Also, JP Laid-Open Patent Publication No. 2002-324374 discloses a method in which a slider revolves centering a support projection while a load beam is in a stationary state. The above identified document also discloses a configuration of counter balances which, so as to align a center of inertia of a revolving portion including the slider with the support projection, are portions of a slider retaining plate, arranged at both tip ends of the slider retaining plate, and are arranged in a line-symmetric manner with respect to a central axis passing through the support projection of the load beam. With such configuration, the axis of inertia of the slider rotary portion including the slider retaining plate substantially aligns with the support projection. With such configuration, when the slider separates from a disk by lifting against a negative pressure coming from an air bearing of the slider, an orientation of the slider is stabilized.
However, the above stated conventional configuration has been problematic in that counterforce generated when the slider is slightly displaced by a pair of displacement members excites a resonance at a resonant frequency of the load beam, thereby not allowing a high speed positioning of the magnetic head with respect to a predetermined track on a disk.
Further, the method disclosed in JP Laid-Open Patent Publication No. 2002-324374 has been problematic also in that since the inertial mass of the rotary portion including the slider becomes great, the resonant frequency of a rotation mode of the slider is not allowed to be increased. Furthermore, the method identified above causes a necessity to accurately adjust a centroid of the rotary portion in order not to excite the resonance at the resonant frequency of the load beam. Also, since the counter balance according to the configurations identified above is shaped such as to bulge outwardly from both sides of the head support mechanism, a wind generated by the rotation of the disk greatly influences a head positioning performance.
The conventional configurations has been problematic in that the counterforce, the force being generated when the slider is slightly displaced by the pair of displacement members, excites a resonance (referred to as a SWAY mode) at a resonant frequency of the load beam, causing unnecessary vibration for the load beam, and it becomes impossible to position the head at a high speed with respect to a track on the disk. Further, it is desirable that, in order to allow the high speed positioning of the head without receiving unnecessary resonance due to the influence of the wind generated by the high-speed rotation of the disk, the resonant frequency of the slider rotation mode which combines the slider and the gimbal part is increased. The present invention is, in light of the above mentioned issues, intended to provide a head support mechanism operable to suppress unnecessary resonance while allowing high responsiveness in precision positioning of the head.