Voice coil motor

Patent metadata

Field	Value
Publication number	US-11768422-B2
Application number	US-202117378501-A
Country	US
Kind code	B2
Filing date	Jul 16, 2021
Priority date	Nov 16, 2011
Publication date	Sep 26, 2023
Grant date	Sep 26, 2023

Abstract

A VCM is disclosed, the motor including a stator including a first driving unit, a rotor arranged inside the stator, including a second driving unit responding to the first driving unit and mounted therein with a lens, a base fixing the stator, and an elastic member coupled to the rotor to float the rotor from the base in a case a driving signal for driving the first and second driving units is not applied to the first and second driving units.

First claim

The invention claimed is:

1. A voice coil motor, comprising:
a base;
a cover disposed on the base and comprising an upper plate and a lateral plate extending from the upper plate;
a bobbin disposed in the cover member;
a magnet disposed between the lateral plate of the cover and the bobbin; and
a coil facing the magnet;
wherein the bobbin is spaced apart from the base at an initial position when no current is applied to the coil,
wherein the bobbin is configured to move from the initial position to a close-up focus position in a first direction distancing from the base when a first driving current is applied to the coil,
wherein the bobbin is configured to move from the initial position to an infinite focus position in a second direction approaching the base when a second driving current is applied to the coil, and
wherein a first stroke length between the initial position and the close-up focus position is greater than a second stroke length between the initial position and the infinite focus position.

2. The voice coil motor of claim 1 , wherein the bobbin is spaced apart from the base at the infinite focus position.

3. The voice coil motor of claim 1 , wherein the bobbin is spaced apart from the upper plate of the cover at the close-up focus position.

4. The voice coil motor of claim 1 , wherein the first stroke length is shorter than a first maximum moving length of the bobbin in the first direction.

5. The voice coil motor of claim 4 , wherein the second stroke length is shorter than a second maximum moving length of the bobbin in the second direction.

6. The voice coil motor of claim 5 , wherein the first maximum moving length is greater than the second maximum moving length.

7. The voice coil motor of claim 4 , wherein the bobbin comprises a first stopper configured to contact the upper plate of the cover in the first direction, and
wherein the first maximum moving length is same as a first distance between the first stopper of the bobbin and the upper plate of the cover.

8. The voice coil motor of claim 5 , wherein the bobbin comprises a second stopper configured to contact the base in the second direction, and
wherein the second maximum moving length is same as a second distance between the second stopper of the bobbin and the base.

9. The voice coil motor of claim 1 , comprising an elastic member coupled with the bobbin,
wherein the elastic member comprises an upper elastic member and a lower elastic member disposed below the upper elastic member, and
wherein each of the upper elastic member and the lower elastic member comprises an inner elastic unit coupled with the bobbin, an outer elastic unit disposed outside the inner elastic unit and a connection elastic unit connecting the inner elastic unit and the outer elastic unit.

10. The voice coil motor of claim 9 , wherein, at the initial position, the inner elastic unit of the upper elastic member is disposed lower than the outer elastic unit of the upper elastic member and the inner elastic unit of the lower elastic member is disposed lower than the outer elastic unit of the lower elastic member.

11. The voice coil motor of claim 9 , comprising a housing disposed between the cover and the bobbin,
wherein the housing comprises an upper surface disposed with the outer elastic unit of the upper elastic member and a groove recessed from the upper surface of the housing, and
wherein the connection elastic unit is disposed at a position corresponding to that of the groove of the housing.

12. The voice coil motor of claim 11 , wherein the magnet is disposed on the bobbin, and
wherein the coil is disposed on the housing.

13. A camera module, comprising:
the voice coil motor of claim 1 ;
a lens coupled with the bobbin of the voice coil motor; and
an image sensor disposed below the lens.

14. The camera module of claim 13 , wherein the lens moves bi-directionally by PWM control.

15. A mobile phone, comprising the camera module of claim 13 .

16. A voice coil motor, comprising:
a base;
a cover disposed on the base and comprising an upper plate and a lateral plate extending from the upper plate;
a bobbin disposed in the cover member; and
a coil and a magnet disposed in the cover and configured to move the bobbin in an optical axis direction,
wherein the bobbin is spaced apart from the base at an initial position when no current is applied to the coil,
wherein the bobbin comprises a first stopper configured to contact the upper plate of the cover in a first direction and a second stopper configured to contact the base in a second direction opposite to the first direction, and
wherein, at the initial position in an optical axis direction, a distance between the first stopper of the bobbin and the upper plate of the cover is greater than a distance between the second stopper of the bobbin and the base.

17. The voice coil motor of claim 16 , wherein the bobbin is configured to move from the initial position to a close-up focus position in the first direction distancing from the base when a first driving current is applied to the coil, and
wherein the bobbin is spaced apart from the upper plate of the cover at the close-up focus position.

18. The voice coil motor of claim 17 , wherein the bobbin is configured to move from the initial position to an infinite focus position in the second direction approaching the base when a second driving current is applied to the coil, and
wherein the bobbin is spaced apart from the base at the infinite focus position.

19. The voice coil motor of claim 18 , wherein a first stroke length between the initial position and the close-up focus position is greater than a second stroke length between the initial position and the infinite focus position,
wherein the first stroke length is shorter than a first maximum moving length of the bobbin in the first direction,
wherein the second stroke length is shorter than a second maximum moving length of the bobbin in the second direction, and
wherein the first maximum moving length is greater than the second maximum moving length.

20. The voice coil motor of claim 19 , wherein the first maximum moving length is same as the distance between the first stopper of the bobbin and the upper plate of the cover.

Assignees

• Lg Innotek Co Ltd

Inventors

• Park Sang Ok
• Lee Seong Min

Classifications

• G03B13/34 Primary

  Power focusing · CPC title

• G02B7/02

  for lenses {(supports for magnifying lenses G02B25/002)} · CPC title

• G02B7/04

  with mechanism for focusing or varying magnification · CPC title

• G02B7/08 Primary

  adapted to co-operate with a remote control mechanism · CPC title

• G02B7/102

  controlled by a microcomputer (cameras with interchangeable lenses G03B17/14) · CPC title