Voice coil motor
A VCM (voice coil motor) is disclosed, the VCM including: a rotor including a cylindrical bobbin for accommodating a lens and protruded at a bottom end with a boss, and a coil block arranged at a periphery of the bobbin; a stator including a magnet facing the coil block and a yoke fixing the magnet; and an elastic member including a first elastic member formed with a through hole coupled to the boss of the bobbin and a second elastic member coupled to an upper end facing the bottom end of the bobbin; wherein the boss is formed with a disengagement prevention unit preventing the first elastic member from being disengaged from the boss, and the first elastic member is formed with a coupling unit contacting a joint where the disengagement prevention unit and the coupling unit meet.
1. A voice coil motor comprising:
a base;
a yoke disposed over the base;
a bobbin disposed inside the yoke and including plurality of first protrusions at a lower portion thereof;
a coil block disposed on a side surface of the bobbin;
a magnet facing the coil block and secured to the yoke; and
a first elastic member coupled to the lower portion of the bobbin;
wherein the first elastic member includes a first spring and a second spring separated from the first spring, and each of the first and second springs includes an outer elastic unit, an inner elastic unit and a connection elastic unit, respectively;
wherein a portion of the inner elastic unit of the first spring includes a first through hole corresponding to a first protrusion of the plurality of first protrusions;
wherein a portion of the inner elastic unit of the second spring includes a second through hole corresponding to a first protrusion of the plurality of first protrusions;
wherein a first protrusion of the plurality of first protrusions is disposed at a location corresponding to the first through hole;
wherein a first protrusion of the plurality of first protrusions is disposed at a location corresponding to the second through hole;
wherein the bobbin is coupled to the first spring where the inner elastic unit of the first spring meets the connection elastic unit of the first spring;
wherein the bobbin is coupled to the second spring where the inner elastic unit of the second spring meets the connection elastic unit of the second spring; and
wherein the coil block includes two distal ends, and one distal end of the coil block is electrically connected to the first spring by a solder and the other distal end of the coil block is electrically connected to the second spring by a solder.
2. The voice coil motor of claim 1 , wherein the plurality of first protrusions includes four protrusions.
3. The voice coil motor of claim 1 , wherein the bobbin further includes a boss formed at the lower portion of the bobbin.
4. The voice coil motor of claim 1 , wherein a disengagement prevention unit is formed at each first protrusion.
5. The voice coil motor of claim 4 , wherein the disengagement prevention unit is formed at a distal end of each first protrusion by applying heat or pressure.
6. The voice coil motor of claim 4 , wherein each disengagement prevention unit has a larger area than that of each first protrusion, respectively.
7. The voice coil motor of claim 1 , further comprising a second elastic member coupled to an upper portion of the bobbin, wherein the second elastic member includes an outer elastic unit, an inner elastic unit, and a connection elastic unit.
8. The voice coil motor of claim 7 , wherein the bobbin includes a second protrusion at the upper portion of the bobbin, and wherein a portion of the inner elastic unit of the second elastic member includes a groove formed at a location corresponding to the second protrusion of the bobbin.
9. The voice coil motor of claim 8 , wherein the groove takes a shape of encompassing the second protrusion at a distal end of the inner elastic unit.
10. The voice coil motor of claim 8 , wherein the inner elastic unit of the second elastic member includes a plurality of openings along a periphery thereof, and one end of the connection elastic unit of the second elastic member is connected to the inner elastic unit of the second elastic member at a location between two openings.
11. The voice coil motor of claim 1 , further comprising a terminal bent at a portion of each outer elastic unit of the first and second springs, respectively.