Lens holder drive device, camera module, and portable terminal provided with camera

• US 9,568,743 B2
• Filed: 08/04/2014
• Issued: 02/14/2017
• Est. Priority Date: 08/09/2013
• Status: Active Grant

• Current Assignee: Mitsumi Electric Co., Ltd. (MinebeaMitsumi Inc.)
• Original Assignee: Mitsumi Electric Co., Ltd. (MinebeaMitsumi Inc.)
• Inventors: Hayashi, Ichiro
• Primary Examiner(s): Cherry, Euncha
• Application Number:
  US14/910,496
• Publication Number:
  US 20160187668A1
• Time in Patent Office: 925 Days
• Field of Search: 359/507, 359/557
• US Class Current: 1/1
• CPC Class Codes: G02B 13/001 Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras G02B23/243 takes precedence
• CPC Class Codes: G02B 27/0006 with means to keep optical surfaces clean, e.g. by preventing or removing dirt, stains, contamination, condensation G02B1/18 takes precedence; cleaning in general B08B
• CPC Class Codes: G02B 27/646 compensating for small deviations, e.g. due to vibration or shake movement of one or more optical elements for control of motion blur in cameras, projectors or printers G03B2205/0007; image stabilisation in cameras peculiar to the presence or use of an electronic image sensor H04N23/68
• CPC Class Codes: G02B 7/09 adapted for automatic focusing or varying magnification
• CPC Class Codes: G03B 13/36 Autofocus systems
• CPC Class Codes: G03B 2205/0007 Movement of one or more optical elements for control of motion blur imaging systems in general using optical elements for stabilisation of the position of the image G02B27/64
• CPC Class Codes: G03B 2205/0069 using electromagnetic actuators, e.g. voice coils
• CPC Class Codes: G03B 3/10 Power-operated focusing
• CPC Class Codes: G03B 5/00 Adjustment of optical system relative to image or object surface other than for focusing
• CPC Class Codes: H04N 23/52 Elements optimising image sensor operation, e.g. for electromagnetic interference [EMI] protection or temperature control by heat transfer or cooling elements
• CPC Class Codes: H04N 23/55 Optical parts specially adapted for electronic image sensors; Mounting thereof
• CPC Class Codes: H04N 23/57 Mechanical or electrical details of cameras or camera modules specially adapted for being embedded in other devices

Abstract

A lens holder driving apparatus includes: an auto-focusing lens holder driving section (AF section) including a permanent magnet; and a camera-shake correcting section that corrects camera-shake by moving the AF section with respect to a fixed section. The camera-shake correcting section includes: a supporting member that supports the AF section in a rocking manner; and a camera-shake correction coil disposed on the fixed section. The fixed section includes: a coil substrate having an inner peripheral side wall defiling a circular opening; a flexible printed-circuit board (FPC) disposed at a lower part of the coil substrate, a base that faces the FPC, and a dust generation prevention member that covers at least the inner peripheral side wall and that prevents generation of dust due to the inner peripheral side wall being scraped.

Claims

1. A lens holder driving apparatus comprising:

an auto-focusing lens holder driving section that moves, along an optical axis (O), a lens holder holding a lens barrel, the auto-focusing lens holder driving section including a permanent magnet; and

a camera-shake correcting section that corrects camera-shake by moving the auto-focusing lens holder driving section in a first direction (X) and a second direction (Y) with respect to a fixed section, the first direction (X) and the second direction (Y) being orthogonal to the optical axis (O) and orthogonal to each other,

wherein the camera-shake correcting section comprises;

a supporting member that supports the auto-focusing lens holder driving section (20) with respect to the fixed section to allow the auto-focusing lens holder driving section (20) to rock in the first direction (X) and the second direction (Y), and

a camera-shake correction coil disposed on the fixed section to face the permanent magnet; and

the fixed section comprises;

a coil substrate on which the camera-shake correction coil is formed, the coil substrate having an inner peripheral side wall defining a circular opening,

a flexible printed-circuit board disposed at a lower part of the coil substrate,

a base that faces the flexible printed-circuit board, and

a dust generation prevention member that covers at least the inner peripheral side wall of the coil substrate and that prevents generation of dust due to the inner peripheral side wall of the coil substrate being scraped, the dust generation prevention member being a member different from the base.

2. The lens holder driving apparatus according to claim 1, wherein:

the dust generation prevention member is composed of a collision avoidance member preventing collision between the inner peripheral side wall of the coil substrate and the lens barrel.

3. The lens holder driving apparatus according to claim 2, wherein:

the collision avoidance member is composed of a ring-shaped cylindrical portion covering the inner peripheral side wall of the coil substrate.

4. The lens holder driving apparatus according to claim 2, wherein:

the collision avoidance member is composed of a metal cover disposed between the flexible printed-circuit board and the base, the metal cover including a ring-shaped cylindrical portion covering the inner peripheral side wall of the coil substrate.

5. The lens holder driving apparatus according to claim 2, wherein:

the collision avoidance member is composed of a metal cover disposed over an upper face of the coil substrate, the metal cover including a ring-shaped cylindrical portion covering the inner peripheral side wall of the coil substrate.

6. The lens holder driving apparatus according to claim 4, wherein:

the metal cover is composed of a copper alloy.

7. The lens holder driving apparatus according to claim 6, wherein:

the copper alloy comprises a copper-nickel-zinc alloy or phosphor bronze.

8. The lens holder driving apparatus according to claim 5, wherein:

the metal cover is composed of a copper alloy.

9. The lens holder driving apparatus according to claim 8, wherein:

the copper alloy comprises a copper—

nickel—

zinc alloy or phosphor bronze.

10. The lens holder driving apparatus according to claim 1, wherein:

the dust generation prevention member is composed of a coating material provided at the inner peripheral side wall of the coil substrate.

11. The lens holder driving apparatus according to claim 10, wherein:

the coating material is obtained by applying a thermoset epoxy resin on the inner peripheral side wall of the coil substrate and heating and curing the thermoset epoxy resin.

12. The lens holder driving apparatus according to claim 1, wherein:

the auto-focusing lens holder driving section comprises;

a focus coil fixed at the lens holder;

a magnet holder disposed at an outer periphery of the lens holder, the magnet holder holding the permanent magnet and including first and second ends facing each other in a direction of the optical axis (O); and

first and second leaf springs respectively attached to the first and the second ends of the magnet holder, the first and the second leaf springs supporting the lens holder to make the lens holder displaceable in the direction of the optical axis (O) while the lens holder is positioned in a radial direction,

the permanent magnet is composed of a plurality of permanent magnet pieces respectively having first faces facing the focus coil, the plurality of permanent magnet pieces being disposed to face each other in the first direction (X) and the second direction (Y) at an external side in a radial direction of the focus coil with respect to the optical axis (O), and

the camera-shake correction coil is composed of a plurality of camera-shake correction coil portions respectively facing second faces perpendicular to the first faces of the plurality of permanent magnet pieces, the plurality of camera-shake correction coil portions being disposed on the fixed section.

13. The lens holder driving apparatus according to claim 12, wherein:

the supporting member is composed of a plurality of suspension wires whose first end portions are fixed at an outer peripheral portion of the fixed section, the plurality of suspension wires extending along the optical axis (O) and supporting the auto-focusing lens holder driving section with respect to the fixed section to allow the auto-focusing lens holder driving section to rock in the first direction (X) and the second direction (Y).

14. The lens holder driving apparatus according to claim 13, wherein:

second end portions of the plurality of suspension wires are fixed at the first leaf spring.

15. A camera module comprising:

the lens holder driving apparatus according to claim 1;

the lens barrel held at the lens holder; and

an imaging device that captures a subject image formed by the lens barrel.

16. A camera-equipped mobile terminal comprising the camera module according to claim 15 mounted therein.