IP Library Granted Patent US 7,518,812
Granted Patent B2
US 7,518,812 · App. 12/025,930 · Granted Apr 14, 2009

Lens drive device

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Quick Facts
Patent No.
US 7,518,812
App. No.
12/025,930
Granted
Apr 14, 2009
Kind
B2
Abstract

A lens drive device includes a lens movable body provided with a lens and a drive mechanism for moving the lens movable body from a home position in an optical axis direction of the lens. The drive mechanism includes a magnet and a plurality of coils which is disposed so that the magnet is interposed in the optical axis direction of the lens. An electric current is supplied to the plurality of the coils in a reverse direction to a direction of an electric current, which is supplied to the plurality of the coils for moving the lens movable body, for restricting movement from the home position of the lens movable body. Therefore, swinging and rattling are hard to occur in the lens movable body and thus its impact resistance can be enhanced.

Claims (21)

1. A lens drive device comprising:

a lens movable body which is provided with a lens;

a drive mechanism for moving the lens movable body from a home position in an optical axis direction of the lens; and

a fixed body which movably supports the lens movable body in the optical axis direction of the lens;

wherein the drive mechanism includes a magnet and a plurality of coils; and

wherein one of the magnet and the plurality of the coils is provided in the lens movable body and the other of the magnet and the plurality of the coils is provided in the fixed body;

wherein an electric current is supplied to the plurality of the coils in one direction to move the lens movable body from the home position in the optical axis direction of the lens; and

wherein, in a state that the lens movable body is located at the home position, an electric current is supplied to the plurality of the coils in a reverse direction to the one direction for maintaining the lens movable body at the home position.

2. The lens drive device according to claim 1 , further comprising an abutting part for restricting the movement of the lens movable body;

wherein in a state that the lens movable body is located at the home position, the electric current is supplied to the plurality of the coils in the reverse direction so that the lens movable body is pressed against the abutting part to be maintaining the lens movable body at the home position.

3. The lens drive device according to claim 2 , wherein the drive mechanism includes an urging member which urges the lens movable body to the home position.

4. The lens drive device according to claim 3 , wherein the drive mechanism includes a magnetic member which is magnetically attracted to the magnet.

5. The lens drive device according to claim 4 , wherein the magnetic member is formed in a spherical shape.

6. The lens drive device according to claim 2 , wherein the drive mechanism includes a plate spring which urges the lens movable body to the home position.

7. The lens drive device according to claim 6 , wherein the plurality of the coils is provided in the lens movable body and the magnet is provided in the fixed body.

8. The lens drive device according to claim 7 , wherein the lens movable body includes a magnetic member which is magnetically attracted to the magnet.

9. The lens drive device according to claim 1 , wherein the drive mechanism includes an urging member which urges the lens movable body to the home position.

10. The lens drive device according to claim 9 , wherein the drive mechanism includes a magnetic member which is magnetically attracted to the magnet.

11. The lens drive device according to claim 10 , wherein the magnetic member is formed in a spherical shape.

12. The lens drive device according to claim 1 , wherein the drive mechanism includes a magnetic member which is magnetically attracted to the magnet.

13. The lens drive device according to claim 12 , wherein the magnetic member is formed in a spherical shape.

Assignments (3)
CORRECTIVE ASSIGNMENT TO CORRECT THE RECEIVING PARTY ADDRESS PREVIOUSLY RECORDED AT REEL: 036714 FRAME: 0757. ASSIGNOR(S) HEREBY CONFIRMS THE CHANGE OF NAME. Recorded Nov 9, 2015
From: SAMSUNG TECHWIN CO., LTD.
To: HANWHA TECHWIN CO., LTD.
Reel/Frame 037072/0008 →
CHANGE OF NAME Recorded Sep 29, 2015
From: SAMSUNG TECHWIN CO., LTD.
To: HANWHA TECHWIN CO., LTD.
Reel/Frame 036714/0757 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Apr 30, 2008
From: SUE, TAKESHI; FURUYA, YUKIO; SUH, JAEGYEONG
To: NIDEC SANKYO CORPORATION; SAMSUNG TECHWIN CO., LTD.
Reel/Frame 020884/0148 →