Lens driving device and camera

Patent metadata

Field	Value
Publication number	US-9933628-B2
Application number	US-201314377185-A
Country	US
Kind code	B2
Filing date	Feb 14, 2013
Priority date	Feb 14, 2012
Publication date	Apr 3, 2018
Grant date	Apr 3, 2018

Abstract

A lens driving device includes: a lens holder; a first coil wound onto the lens holder around the optical axis direction; a plurality of magnets having a first surface and a second surface perpendicular to the first surface, the magnets being disposed in a state in which the first surface opposes a circumferential surface of the first coil; a magnet holder that fixes the magnets apart from each other; a yoke constituting, together with the magnets, a magnetic circuit having a magnetic flux that traverses the first coil; a second coil provided opposite the second surface of the magnets; and a base on which the second coil is disposed. An auto-focus lens driving part that includes the lens holder, the first coil, the magnets, the magnet holder, and the yoke is held on the base so as to allow relative displacement in a direction perpendicular to the optical axis.

First claim

The invention claimed is:

1. A lens driving device, comprising:
a lens holder to which a lens barrel is mounted, the lens holder being movable in a direction of an optical axis;
a first coil for auto-focusing wound around the lens holder about the optical axis;
a plurality of magnets that each have a rectangular shape extending in a longitudinal direction and a short-side direction orthogonal to the longitudinal direction while being magnetized in the short-side direction, wherein each of the plurality of magnets has a first surface that extends in the longitudinal direction and magnetized to a south pole or a north pole and a second surface that is perpendicular to the first surface and the optical axis, the first surface of the plurality of magnets facing a circumferential face of the first coil;
a magnet holder that fixes the plurality of magnets apart from each other;
a yoke comprising, together with the plurality of magnets, a magnetic circuit that generates a magnetic flux that crosses the first coil;
a second coil for image stabilizing that comprises a plurality of image stabilizer coil portions, each provided such that a coil plane thereof faces the second surface of a corresponding one of the plurality of magnets and each having a shape extending in the longitudinal direction of the magnet, which is opposite thereto; and
a base on which the second coil is disposed,
wherein an auto-focusing lens driving portion that includes the lens holder, the first coil, the plurality of magnets, the magnet holder and the yoke is held so as to be relatively movable in first and second directions perpendicular to the optical axis with respect to the base,
a position detection arrangement that detects a position of the auto-focusing lens driving portion with respect to the base, comprising:
a plurality of Hall elements, each provided facing the second surface of a corresponding one of the plurality of magnets,
wherein the plurality of image stabilizer coil portions include specific image stabilizer coil portions disposed in the first and the second directions, each of the specific image stabilizer coil portions being divided into a plurality of coil parts disposed along the longitudinal direction of the magnet, which is opposite thereto, and
wherein each Hall element of the plurality of Hall elements is disposed on an imaginary line parallel to the optical axis and passing between two of the plurality of coil parts of each of the specific image stabilizer coil portions.

2. The lens driving device according to claim 1 , wherein the magnet holder is a polygonal frame body.

3. The lens driving device according to claim 2 , wherein the plurality of magnets are fixed to the magnet holder at positions such that adjacent magnets are in a perpendicular relationship with respect to each other.

4. The lens driving device according to claim 3 , wherein a number of the magnets is four.

5. The lens driving device according to claim 1 , wherein a number of the first yoke portions is four.

6. The lens driving device according to claim 1 , wherein the yoke is fixed to the magnet holder.

7. The lens driving device according to claim 1 , wherein:
the yoke comprises further a plurality of members; and
a predetermined part of the lens holder is located in a space between two of the plurality of members.

8. The lens driving device according to claim 1 , wherein an image pickup device is mounted on the base.

9. A camera comprising the lens driving device according to claim 1 incorporated therein.

10. The lens driving device according to claim 1 , wherein the yoke further comprises a plurality of first yoke portions disposed apart from each other, and a frame-shaped second yoke portion, one of the plurality of the first yoke portions extending from an inner edge of the second yoke portion so as to correspond to a separation part between adjacent magnets and being disposed so that the first coil is positioned between the one of the plurality of the first yoke portions and the adjacent magnets, the second yoke portion being disposed facing a third surface opposite to the second surface of the plurality of magnets, and
wherein the one of the plurality of the first yoke portion comprises a first wall surface that faces a separation part between the adjacent magnets, and second wall surfaces that face end portions of the adjacent magnets, respectively.

Assignees

• Ariji Makoto
• Mitsumi Electric Co Ltd

Inventors

• Ariji Makoto

Classifications

• H04N23/57

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

• H04N23/687

  by shifting the lens or sensor position · CPC title

• G03B3/10

  Power-operated focusing · CPC title

• G03B2205/0007

  Movement of one or more optical elements for control of motion blur · CPC title

• G02B7/023 Primary

  permitting adjustment · CPC title