Disk drive actuator latch apparatus and method
An actuator latch apparatus for a disk drive. The latch apparatus includes a metal piece disposed at one end of the swing arm, an attracting part protruded from an edge of the yoke, for attracting the metal piece by a magnetic force of the magnet, a hole formed at a position corresponding to the metal piece of the attracting part, for leaking magnetic flux flowing through the attracting part, a core disposed to move through the hole, and a core transfer device for transferring the core in one direction such that a leading end portion of the core is inserted into the hole when the disk drive operates, and for transferring the core in an opposite direction such that the core is released from the hole when the disk drive is stopped. Accordingly, a locking state of the actuator can be maintained more stably and released more easily.
1. An actuator latch apparatus locking an actuator, the actuator including a swing arm, a VCM coil coupled to one end of the swing arm, a magnet disposed facing the VCM coil, and a yoke supporting the magnet, the actuator latch apparatus comprising:
a swing arm protrusion disposed on the swing arm;
an attracting part, protruding from the yoke, for attracting the swing arm protrusion by a magnetic force of the magnet;
a hole formed in the attracting part, at a position corresponding to the swing arm protrusion, for leaking magnetic flux flowing through the attracting part;
a core disposed to move through the hole; and
a core transfer device transferring the core such that a leading end portion of the core is inserted into the hole when a disk drive is operating, and for transferring the core such that the core is released from the hole when the disk drive is not operating.
2. The actuator latch apparatus of claim 1 , wherein the core transfer device comprises:
a bobbin enclosing the core and movably supporting the core;
a solenoid coil wound on an outer circumference of the bobbin; and
a permanent magnet, disposed adjacent to a rear end portion of the bobbin, for magnetically attracting the core.
3. The actuator latch apparatus of claim 2 , wherein when a current is not applied to the solenoid coil, the core is magnetically drawn toward the permanent magnet and is released from the hole, and when a current is applied to the solenoid coil, the rear end of the core is magnetized to a polarity corresponding to the permanent magnet and the core is repulsed from the permanent magnet to insert the leading end portion of the core into the hole.
4. The actuator latch apparatus of claim 2 , wherein the magnetic attraction exerted by the permanent magnet upon the core is greater than a magnetic force exerted by the attracting part upon the core.
5. The actuator latch apparatus of claim 2 , wherein the yoke comprises an upper yoke disposed above the VCM coil and a lower yoke disposed below the VCM coil, with the core transfer device being installed at the lower yoke.
6. The actuator latch apparatus of claim 5 , wherein the lower yoke has a supporting part supporting the core transfer device.
7. The actuator latch apparatus of claim 6 , wherein the bobbin and the permanent magnet are fixed on an upper surface of the supporting part.
8. The actuator latch apparatus of claim 1 , wherein the hole has a circular shape of which a side is opened toward the swing arm protrusion, and the core has a circular section corresponding to the circular shape of the hole.
9. The actuator latch apparatus of claim 1 , wherein the swing arm protrusion further comprises a damper with a magnetic material being attached to an end of the damper to be magnetically interactive with the attracting part.
10. The actuator latch apparatus of claim 1 , wherein the yoke comprises an upper yoke disposed above the VCM coil and a lower yoke disposed below the VCM coil, with the attracting part being protruding from an edge of the upper yoke and bent such that an end of the attracting part contacts an upper surface of the lower yoke.
11. A disk drive, comprising:
a read and/or write head for reading and/or writing from/to a disk; and
an actuator comprising an actuator latch apparatus locking the actuator, the actuator latch apparatus comprising a swing arm protrusion disposed on a swing arm of the actuator, an attracting part, protruding from a yoke of the actuator, for magnetically attracting the swing arm protrusion, and a magnetic interfering apparatus selectively located near the attracting part to lower the magnetic attraction between the swing arm protrusion and the attracting part thereby reducing a required torque necessary to distance the swing arm protrusion from the attracting part for unlocking the actuator latch apparatus.
12. The disk drive of claim 11 , wherein the magnetic interfering apparatus comprises a portion corresponding a hole of the attracting part leaking magnetic flux flowing through the attracting part, wherein the lowering of the magnetic attraction between the swing arm protrusion and the attracting part is implemented by inserting the portion of the magnetic interfering apparatus into the hole of the attracting part.
13. An actuator latch locking method for an actuator, the actuator including a swing arm, a VCM coil coupled to one end of the swing arm, a magnet disposed facing the VCM coil, and a yoke supporting the magnet, the actuator latch method comprising:
magnetically attracting a swing arm protrusion, disposed on the swing arm, by a hole formed in an attracting part of the yoke leaking magnetic flux flowing through the attracting part; and
transferring a leading portion of a core into the hole when a disk drive is operating to reduce a magnetic force between the swing arm protrusion and the attracting part to control the leaking of magnetic flux and transferring the leading portion of the core from the hole when the disk drive is not operating to withdraw the reduction in magnetic force.
14. The actuator latch method of claim 13 , wherein when a current is not applied to a solenoid coil controlling the transferring of the core, the core is magnetically drawn toward a permanent magnet away from the attracting part and is released from the hole, and when a current is applied to the solenoid coil, a rear portion of the core is magnetized to a polarity corresponding to the permanent magnet and the core is repulsed from the permanent magnet to insert the leading portion of the core into the hole.
15. The actuator latch method of claim 14 , wherein a magnetic attraction exerted by the permanent magnet upon the core is greater than a magnetic force exerted by the attracting part upon the core.
16. A disk drive operating method, comprising:
reading and/or writing from/to a disk by a read and/or write head; and
selectively locking an actuator supporting the read and/or write head, the locking comprising magnetically attracting a swing arm protrusion, disposed on a swing arm of the actuator, to an attracting part, protruding from a yoke of the actuator, by selectively locating a magnetic interfering apparatus near the attracting part to lower the magnetic attraction between the swing arm protrusion and the attracting part thereby reducing a required torque necessary to distance the swing arm protrusion from the attracting part for unlocking the actuator latch apparatus, and moving the magnetic interfering apparatus away from the attracting part to increase the magnetic attraction between the swing arm protrusion and the attracting part for locking the actuator.
17. The disk drive operating method of claim 16 , wherein the magnetic interfering apparatus comprises a portion corresponding a hole of the attracting part leaking magnetic flux flowing through the attracting part, wherein the method further comprises lowering the magnetic attraction between the swing arm protrusion and the attracting part by inserting the portion of the magnetic interfering apparatus into the hole of the attracting part.