Lens moving unit and camera module having the same

Patent metadata

Field	Value
Publication number	US-9979888-B2
Application number	US-201615373032-A
Country	US
Kind code	B2
Filing date	Dec 8, 2016
Priority date	Mar 17, 2014
Publication date	May 22, 2018
Grant date	May 22, 2018

Abstract

One embodiment of a lens moving unit includes a bobbin mounted with at least one sheet of lens and arranged at a periphery with a coil unit, a cover member mounted with a magnet at a position corresponding to that of the coil unit, upper and bottom elastic members respectively coupled at one distal end to upper and bottom surfaces of the bobbin to support movement of the bobbin to an optical axis direction, and a detection unit to detect a movement parallel to an optical axis of the bobbin, wherein the detection unit includes a sensing magnet mounted at a periphery of the bobbin, and a position detection sensor arranged at a lateral wall of the cover member and formed at an inner lateral surface opposite to the sensing magnet, wherein the bobbin includes a correction magnet mounted at a side opposite to that of the sensing magnet.

First claim

What is claimed is:

1. A lens moving unit, the lens moving unit comprising:
a cover member comprising an upper surface and a plurality of lateral walls extending from the upper surface;
a bobbin disposed in the cover member and configured to move in an optical axis direction;
a driving magnet disposed on the cover member;
a coil unit disposed on the bobbin and facing the driving magnet;
a circuit substrate comprising a plurality of terminals disposed on a bottom end thereof;
a base disposed below the bobbin and coupled to the cover member;
a sensing magnet disposed on the bobbin and under or over the coil unit; and
a position detection sensor disposed on the circuit substrate and configured to detect the sensing magnet;
wherein the plurality of lateral walls of the cover member comprises first and second lateral walls opposite to each other, and third and fourth lateral walls disposed between the first and second lateral walls and opposite to each other;
wherein the driving magnet comprises a first magnet facing the first lateral wall of the cover member and a second magnet facing the second lateral wall of the cover member,
wherein the driving magnet is omitted from the third and fourth lateral walls of the cover member, and
wherein the sensing magnet is disposed on a side of the bobbin that faces a direction towards the third lateral wall of the cover member.

2. The lens moving unit of claim 1 , further comprising a correction magnet disposed on the bobbin, and
wherein the correction magnet is disposed opposite to the sensing magnet and disposed on a side of the bobbin that faces a direction towards the fourth lateral wall of the cover member.

3. The lens moving unit of claim 2 , wherein the sensing magnet and the correction magnet are arranged at a position not to face the driving magnet, and the sensing magnet and the correction magnet are smaller than the driving magnet.

4. The lens moving unit of claim 1 , wherein the sensing magnet is not overlapped with the third lateral wall of the cover member in a direction perpendicular to a surface of the third lateral wall that faces the bobbin.

5. The lens moving unit of claim 1 , wherein the cover member is formed with a metal,
wherein the cover member is integrally formed with an inner yoke,
wherein the inner yoke of the cover member comprises four inner yokes and the four inner yokes are disposed at positions corresponding to four corners of the cover member, respectively;
wherein the bobbin comprises a first groove disposed at a position corresponding to the inner yoke of the cover member, and
wherein one side surface of the inner yoke is spaced apart from the coil unit and the other side surface of the inner yoke is spaced apart from the bobbin.

6. The lens moving unit of claim 5 , wherein the inner yoke of the cover member is bent from the upper surface of the cover member, and
wherein the inner yoke of the cover member comprises a second groove near a bent portion of the inner yoke.

7. The lens moving unit of claim 2 , wherein an imaginary line connecting a center of the sensing magnet and a center of the correction magnet passes the optical axis when viewed from the top.

8. The lens moving unit of claim 1 , further comprising:
an elastic member coupled with the bobbin,
wherein the elastic member comprises a lower elastic member coupled to a lower surface of the bobbin, and an upper elastic member coupled to an upper surface of the bobbin;
wherein the lower elastic member comprises a first spring and a second spring spaced from each other,
wherein the first spring is electrically connected with one end of the coil unit, and
wherein the second spring is electrically connected with the other end of the coil unit, and
wherein the first spring and the second spring are electrically connected with the circuit substrate.

9. The lens moving unit of claim 8 , wherein at least a portion of the circuit substrate is disposed on a lateral surface of the base.

10. The lens moving unit of claim 1 , wherein the position detection sensor is a Hall sensor, and
wherein the sensing magnet comprises six surfaces.

11. The lens moving unit of claim 1 , wherein a sensing magnet mounting unit is formed at a periphery of the bobbin and the sensing magnet is disposed in the sensing magnet mounting unit such that the sensing magnet mounting unit wraps at least three surfaces of the sensing magnet.

12. The lens moving unit of claim 11 , wherein the sensing magnet mounting unit comprises a groove part formed at the periphery of the bobbin.

13. The lens moving unit of claim 11 , wherein the sensing magnet is fixed to the sensing magnet mounting unit using an adhesive and the sensing magnet does not protrude from the periphery of the bobbin.

14. The lens moving unit of claim 11 , wherein the sensing magnet faces the coil unit in the optical axis direction or contacts the coil unit.

15. The lens moving unit of claim 1 , wherein the sensing magnet faces the coil unit in the optical axis direction or contacts the coil unit.

16. The lens moving unit of claim 1 , further comprising a housing disposed in the cover member;
wherein the driving magnet is disposed on the housing and fixed to the cover member.

17. The lens moving unit of claim 2 , wherein the sensing magnet and the correction magnet are so disposed as not to overlap with the driving magnet in a direction from the sensing magnet toward the correction magnet.

18. The lens moving unit of claim 1 , wherein the circuit substrate is disposed on the third lateral wall of the cover member.

19. A camera module comprising:
the lens moving unit of claim 1 ;
a lens barrel coupled to the bobbin;
an image sensor; and
a PCB (Printed Circuit Board) mounted with the image sensor,
wherein the plurality of terminals of the circuit substrate are electrically connected to the PCB (Printed Circuit Board).

20. The camera module of claim 19 , wherein the camera module is configured to perform AF (Auto Focus) by receiving a position information of the bobbin using the sensing magnet and the position detection sensor.

Assignees

• Lg Innotek Co Ltd

Inventors

• Jung Tae Jin
• Min Sang Jun

Classifications

• H04N23/54

  Mounting of pick-up tubes, electronic image sensors, deviation or focusing coils · CPC title

• H04N23/55

  Optical parts specially adapted for electronic image sensors; Mounting thereof · CPC title

• H04N23/6812

  based on additional sensors, e.g. acceleration sensors · CPC title

• H04N23/687 Primary

  by shifting the lens or sensor position · CPC title

• H04N23/57

  Mechanical or electrical details of cameras or camera modules specially adapted for being embedded in other devices · CPC title