VOICE COIL MOTOR AND DRIVING MEHOD THEREOF

• US 20130136438A1
• Filed: 11/27/2012
• Published: 05/30/2013
• Est. Priority Date: 11/30/2011
• Status: Abandoned Application

• Current Assignee: LG Innotek Company Limited (LG Corporation)
• Original Assignee: LG Innotek Company Limited (LG Corporation)
• Inventors: LEE, Seong Min, PARK, Sang Ok
• Application Number:
  US13/686,709
• Publication Number:
  US 20130136438A1
• Time in Patent Office: Days
• US Class Current: 396/133
• CPC Class Codes: G02B 7/023 permitting adjustment
• CPC Class Codes: G02B 7/08 adapted to co-operate with a remote control mechanism
• CPC Class Codes: G03B 2205/0069 using electromagnetic actuators, e.g. voice coils
• CPC Class Codes: G03B 3/10 Power-operated focusing

Abstract

A VCM is disclosed, the VCM including a stator including a first driving unit fixed to a base to generate a first magnetic field, a rotor including a bobbin mounted with a lens to vertically move relative to the base and a second driving unit generating a second magnetic field reacting to the first magnetic field, an elastic member connected to the stator and the rotor to elastically support the rotor, and a position sensor arranged to any one of the first and second driving units to sense a position of the rotor relative to the stator.

Claims

1. A VCM, the VCM comprising:

a stator including a first driving unit fixed to a base to generate a first magnetic field;

a rotor including a bobbin mounted with a lens to vertically move relative to the base and a second driving unit generating a second magnetic field reacting to the first magnetic field;

an elastic member connected to the stator and the rotor to elastically support the rotor; and

a position sensor arranged to any one of the first and second driving units to sense a position of the rotor relative to the stator.

2. The VCM of claim 1, wherein the position sensor including a Hall sensor sensing the position of the rotor by using changes in magnetic field.

3. The VCM of claim 1, wherein the first driving unit includes at least one magnet, and the second driving unit includes a coil block formed by winding an insulated wire on the bobbin.

4. The VCM of claim 3, wherein the position sensor is arranged on the second driving unit opposite to the first driving unit.

5. The VCM of claim 1, wherein the first driving unit includes a coil block formed by winding an insulated wire on the bobbin, and the second driving unit includes a magnet.

6. The VCM of claim 5, wherein the position sensor is arranged on the first driving unit.

7. The VCM of claim 1, wherein the elastic member is formed in a pair, and includes a first elastic member arranged at a bottom surface of the bobbin, and a second elastic member arranged at an upper surface of the bobbin opposite to the bottom surface of the bobbin.

8. The VCM of claim 1, wherein the rotor is distanced from the upper surface of the bobbin, in a case the driving signal is not applied to the first and second driving units.

9. The VCM of claim 1, wherein the rotor is arranged at an upper surface of a base, in a case the driving signal is not applied to the first and second driving units.

10. The VCM of claim 1, wherein the position sensor includes a wire outputting a sensed signal, and wherein the wire is electrically connected to a circuit board arranged at a rear surface of the base.

11. A driving method of a VCM, the method comprising:

applying, to a controller, a current position of a rotor vertically moving relative to a stator by sensing the current position of the rotor;

determining, by the controller, the position of the rotor in response to a sensing signal generated from a position sensor;

determining, by the controller, a level of the driving signal for adjusting a gap between the rotor and an image sensor opposite to the rotor based on the sensing signal; and

adjusting the gap between the rotor and the image sensor by applying the driving signal to the rotor or to the stator in response to the level of the driving signal.

12. The method of claim 11, wherein the stator is arranged at an upper surface of a base to include a first driving unit, and the rotor includes a second driving unit.

13. The method of claim 12, wherein the rotor is distanced from the upper surface of the base to float, in a case the first and second driving units are not applied with the driving signal.

14. The method of claim 12, wherein the rotor is brought into contact with the upper surface of the base, in a case the first and second driving units are not applied with the driving signal.

15. The method of claim 12, wherein the position sensor is arranged on any one of the first and second driving units, and includes a Hall sensor generating a sensing signal in response to position change in the rotor.

16. The method of claim 15, wherein the Hall sensor is arranged on the first driving unit.

17. The method of claim 15, wherein the Hall sensor is arranged on the second driving unit.

18. The method of claim 12, wherein the first driving unit includes a magnet, and the second driving unit includes a coil block.

19. The method of claim 12, wherein the first driving unit includes a coil block, and the second driving unit includes a magnet.