CN-115349103-B - Lens driving device, camera module, and camera mounting device

CN115349103BCN 115349103 BCN115349103 BCN 115349103BCN-115349103-B

Abstract

A lens driving device includes a movable portion, a driving portion, a magnet portion having a first magnetic pole and a second magnetic pole, and a position detecting portion disposed so as to face the magnet portion, wherein the position of the magnet portion is detected by detecting a magnetic field in a plane including a direction of an optical axis and a width direction, and a boundary extends so as to be curved so that an angle formed by the boundary and the direction of the optical axis changes.

Inventors

KAIBARA SHOKICHI
HARUKI TAKASHI

Assignees

三美电机株式会社
三美电机株式会社

Dates

Publication Date: 20260421
Application Date: 20210311
Priority Date: 20210311

Claims (11)

1. A lens driving device is provided with: a movable unit capable of holding a movable lens; a driving unit that drives the movable unit in the direction of the optical axis; A magnet part provided in the movable part and extending in the direction of the optical axis and having a first magnetic pole and a second magnetic pole arranged adjacently to each other across a boundary in a width direction orthogonal to the direction of the optical axis, and A position detection unit which is disposed so as to face the magnet unit and detects a magnetic field in a plane including the direction of the optical axis and the width direction to thereby detect the position of the magnet unit, The position detecting section includes a magnetoresistive sensor, The boundary extends in a curved manner such that an angle formed by the boundary and the direction of the optical axis changes.
2. The lens driving apparatus according to claim 1, wherein, The boundary extends in a curved manner such that the magnet portion is displaced from one side where the first magnetic pole is located in the width direction to one side where the second magnetic pole is located as the magnet portion approaches from an end portion on one side in the direction of the optical axis to a predetermined position in the direction of the optical axis, and the magnet portion is displaced from one side where the second magnetic pole is located in the width direction to one side where the first magnetic pole is located as the magnet portion approaches from the predetermined position to an end portion on the other side in the direction of the optical axis.
3. The lens driving apparatus according to claim 1, wherein, The boundary extends in a curved manner such that an angle formed by the boundary and the direction of the optical axis continuously changes.
4. The lens driving apparatus according to claim 1, wherein, The boundary extends so as to be curved so as to form a magnetic field in which a direction of magnetic flux at a portion of the magnet portion facing the position detection portion changes with movement of the magnet portion.
5. The lens driving apparatus according to claim 1, wherein, The boundary extends in an arcuate curve.
6. The lens driving apparatus according to claim 1, wherein, The magnet portion extends linearly with a constant width in the direction of the optical axis, The ratio of the width of the first magnetic pole to the width of the second magnetic pole varies corresponding to the curvedly extending boundary.
7. The lens driving apparatus according to claim 1, wherein, The position detection unit includes a plurality of magnetoresistive sensors arranged side by side in a direction of the optical axis.
8. The lens driving apparatus according to claim 1, wherein, The movable part has a first movable part and a second movable part capable of holding the first movable lens and the second movable lens respectively, The driving unit includes a first driving unit and a second driving unit that drive the first movable unit and the second movable unit in the direction of the optical axis, respectively, the first driving unit and the second driving unit being disposed on one end side, one of both ends of the first movable unit and the second movable unit sandwiching the optical axis, The first movable portion and the second movable portion are each provided with the magnet portion.
9. The lens driving apparatus according to claim 8, wherein, The first driving part is provided with a first ultrasonic motor and a first frame connected with the first movable part, The second driving part is provided with a second ultrasonic motor and a second frame connected with the second movable part, The first ultrasonic motor and the second ultrasonic motor are arranged side by side in the direction of the optical axis on the one end side, and independently drive the first movable portion and the second movable portion in the direction of the optical axis, respectively.
10. A camera module, comprising: The lens driving apparatus of claim 1; A lens section including the movable lens held by the movable section, and An imaging unit configured to capture an image of the subject imaged by the lens unit, The camera module drives the movable lens in the direction of the optical axis.
11. A camera mounting device is an information device or a transportation device, and comprises: the camera module of claim 10, and And an imaging control unit that processes image information obtained by the camera module.

Description

Lens driving device, camera module, and camera mounting device Technical Field The invention relates to a lens driving device, a camera module and a camera mounting device. Background Conventionally, a camera module mounted on a thin camera mounting device such as a smart phone is known. As such a camera module, a camera module provided with a lens driving device having a zoom function for enlarging or reducing an object image to be photographed is known. For example, patent document 1 discloses a structure including a fixed lens into which light from an object is incident, two movable lenses into which light refracted by the fixed lens is incident, and a lens driving unit for moving the two movable lenses in the direction of the optical axis. In such a lens driving device, in order to detect the position of the movable lens in the direction of the optical axis, a magnet portion and a position detecting portion (for example, a hall element) that detects the magnetic flux of the magnet portion are provided in a movable portion in which the movable lens is provided. For example, two adjacent different magnetic poles (N-pole and S-pole) are arranged in the magnet portion, and the magnet portion is arranged such that the magnetic force at the opposing portion opposing the position detecting portion varies corresponding to the position of the movable lens. Prior art literature Patent literature Patent document 1 Japanese patent application laid-open No. 2018-36416 Disclosure of Invention Problems to be solved by the invention However, in a small-sized camera mounting apparatus, for example, if the positions of the magnet portions in the opposing directions of the two different magnetic poles are deviated from desired positions due to assembly errors or the like, the positional relationship with the position detection portion is also deviated, and therefore, there is a possibility that the position of the movable lens cannot be accurately detected. The invention aims to provide a lens driving device, a camera module and a camera mounting device capable of accurately detecting the position of a movable lens. Solution to the problem The lens driving device of the present invention comprises: a movable part which is arranged in the direction of the optical axis and can hold the movable lens; A driving unit that drives the movable unit in the direction of the optical axis; A magnet part provided in the movable part and extending in the direction of the optical axis and having a first magnetic pole and a second magnetic pole arranged adjacently to each other across a boundary in a width direction orthogonal to the direction of the optical axis, and A position detection unit which is disposed so as to face the magnet unit and detects a magnetic field in a plane including the direction of the optical axis and the width direction to thereby detect the position of the magnet unit, The boundary extends in a curved manner such that an angle formed by the boundary and the direction of the optical axis changes. The camera module of the present invention comprises: the lens driving device described above; A lens section including the movable lens held by the movable section, and An imaging unit configured to capture an image of the subject imaged by the lens unit, The camera module drives the movable lens in the direction of the optical axis. The camera mounting device of the present invention is an information device or a transportation device, and comprises: the camera module and And an imaging control unit that processes image information obtained by the camera module. Effects of the invention According to the present invention, the position of the movable lens can be accurately detected. Drawings Fig. 1 is a view schematically showing a camera module according to an embodiment of the present invention. Fig. 2 is a diagram schematically showing the structure of the camera module according to the present embodiment when viewed from the side. Fig. 3 is a perspective view showing a housing portion of the camera module. Fig. 4 is a perspective view of the bottom wall portion side in the housing portion of the camera module. Fig. 5 is an exploded perspective view of the housing and the lens portion. Fig. 6 is an exploded perspective view of the side wall portion and the bottom wall portion in the housing. Fig. 7 is a view of the case from the Z direction + side. Fig. 8 is a view of the inside of the case from the-side in the X direction. Fig. 9 is a view showing the guided portion. Fig. 10 is a diagram showing a connection portion between the lens unit and the frame. Fig. 11 is an exploded perspective view of the guided portion and the sandwiching portion. Fig. 12A is a diagram for explaining adjustment of the positional relationship between the sandwiching portion and the guide shaft. Fig. 12B is a diagram for explaining adjustment of the positional relationship between the sandwiching portion and the guide shaft. Fig. 13 is a