Patent ID: 7538985

Claim:
A two-stage actuator type magnetic head positioning mechanism comprising: a plurality of fine actuator sections which minutely drives, by a pair of piezoelectric elements mounted in said fine actuator sections, a magnetic head supporting section adapted to support a slider on which a magnetic head is attached; a plurality of holder arms to support each of said fine actuator sections; an arm block formed by integrally unifying said plurality of holder arms; and a voice coil motor to drive said arm block; wherein said fine actuator section is composed of an actuator spring made from one thin steel plate and a base plate made from one thick steel plate, wherein a driving spring section being connected to said magnetic head supporting section is mounted on said actuator spring, wherein, in a vicinity of said driving spring section, a pair of first driving voids to absorb vibration of said magnetic head supporting section and extension/shrinkage of said pair of piezoelectric elements along a longitudinal axis is formed in a state being symmetrical right and left with respect to the longitudinal axis, each of the piezoelectric elements disposed over a corresponding void of said pair of first driving voids, wherein both end portions of said pair of piezoelectric elements are connected to said magnetic head supporting section and to said actuator spring in a manner such that said end portions of each piezo-electric element straddle the corresponding void of said pair of first driving voids without overlapping a non-corresponding void of said pair of first driving voids, wherein said base plate is junctioned to one face of said actuator spring in a manner such that said base plate covers said pair of first driving voids, and only portions of said actuator spring and said base plate surrounding said pair of first driving voids are laser spot welded, and wherein said base plate comprises a pair of second driving voids substantially complementary to said pair of first driving voids, said pair of second driving voids dividing said base plate into a main portion and a separated portion junctioned to said magnetic head supporting section.