Lens driving device, camera module, and camera mounting device

Patent metadata

Field	Value
Publication number	US-10527818-B2
Application number	US-201715854852-A
Country	US
Kind code	B2
Filing date	Dec 27, 2017
Priority date	Jul 11, 2014
Publication date	Jan 7, 2020
Grant date	Jan 7, 2020

Abstract

Provided is a technology which: has a structure that is advantageous for size reduction and power saving; and, moreover, is useful when automatic focusing using a closed-loop control system. A lens driving device comprising: an autofocus driving unit; a Hall element which separates an autofocus magnet section; a first position detection magnet which is disposed near the Hall element; and a second position detection magnet which has the same configuration as the first position detection magnet and is disposed in a point symmetrical position relating to the first position detection magnet and the optical axis direction.

First claim

What is claimed is:

1. A lens driving device comprising an auto-focusing driving part,
the auto-focusing driving part including:
an auto-focusing coil part disposed at a periphery of a lens part; and
an auto-focusing magnet part composed of four permanent magnets and disposed separately from the auto-focusing coil part in a radial direction, wherein

the auto-focusing driving part is configured to move an auto focus movable part including the auto-focusing coil part in a light axis direction with respect to an auto focus fixing part including the auto-focusing magnet part, wherein
the auto focus fixing part includes:
a Hall device being disposed separately from the auto-focusing magnet part;
a first position detection magnet being disposed in proximity to the Hall device; and
a second position detection magnet having a configuration similar to that of the first position detection magnet, and the second position detection magnet being disposed at a position point symmetrical with the first position detection magnet about the light axis direction, wherein

a magnetic force which acts on the auto focus movable part is balanced.

2. The lens driving device according to claim 1 further comprising a shake-correcting driving part,
the shake-correcting driving part including:
a shake-correcting magnet part disposed at an auto focus unit including the auto focus movable part and the auto focus fixing part; and
a shake-correcting coil part disposed separately from the shake-correcting magnet part in the light axis direction;

the shake-correcting driving part being configured to swing a shake-correcting movable part including the shake-correcting magnet part in a plane orthogonal to the light axis direction with respect to a shake-correcting fixing part including the shake-correcting coil part.

3. The lens driving device according to claim 2 , wherein the auto-focusing magnet part serves also as the shake-correcting magnet.

4. A camera module comprising:
the lens driving device according to claim 1 ;
a lens part mounted to the auto focus movable part; and
an image capturing part configured to capture a subject image imaged by the lens part.

5. A camera mounting device comprising:
the camera module according to claim 4 ;
the camera mounting device being an information device or a transport device.

6. The lens driving device according to claim 1 , wherein:
parts of the first position detection magnet and the auto-focusing magnet part which are close to each other have the same polarity; and
parts of the second position detection magnet and the auto-focusing magnet part which are close to each other have the same polarity.

Assignees

• Murakami Tomoyuki
• Hayashi Ichiro
• Kudo Shota
• Mitsumi Electric Co Ltd

Inventors

• Murakami Tomoyuki
• Hayashi Ichiro
• Kudo Shota

Classifications

• G02B7/04

  with mechanism for focusing or varying magnification · CPC title

• G03B5/00

  Adjustment of optical system relative to image or object surface other than for focusing · CPC title

• G02B27/646

  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 title

• G02B7/102

  controlled by a microcomputer (cameras with interchangeable lenses G03B17/14) · CPC title

• G02B7/09 Primary

  adapted for automatic focusing or varying magnification · CPC title