Lens Holder Elastic Portion Absorbs Stopper Impact Noise

Solution Overview

Problem

Existing lens driving devices using shape memory alloy wires can generate a contact sound when the lens holder moves and contacts a spacer, leading to undesirable noise.

Innovation Solution

A lens driving device is designed with a fixed member, a lens holder, and shape memory alloy wires, where the lens holder includes an elastic portion softer than the synthetic resin material of the cylindrical portion, and a movable contact that faces a fixed contact to absorb the impact and reduce noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a hard stopper structure is used to restrict lens holder movement, then positioning precision is improved, but contact sound and wear increase

Engineering Contradiction:

Improvepositioning precisionVSAvoidcontact sound

Core Design Contradiction:

Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The patent changes the material parameter of the stopper from hard synthetic resin to soft elastic material, transforming the contact characteristics between the stopper and lens holder. This parameter change allows the stopper to deform elastically during contact, absorbing impact energy and reducing contact sound while maintaining positioning precision through the elastic recovery of the material.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses composite material structure where the stopper is made of elastic material (such as rubber or elastomer) that combines softness for noise reduction with sufficient structural integrity for positioning. This composite approach allows the stopper to provide both mechanical constraint and shock absorption functions simultaneously.

Inventive Principle:

Principle #40Composite materials

2Manufacturing precision

If a hard stopper structure is used to restrict lens holder movement, then positioning precision is improved, but wear and foreign matter accumulation increase

Engineering Contradiction:

Improvepositioning precisionVSAvoidwear resistance

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The patent changes the material parameter of the stopper from hard synthetic resin to soft elastic material, transforming the contact characteristics between the stopper and lens holder. This parameter change allows the stopper to deform elastically during contact, absorbing impact energy and reducing contact sound while maintaining positioning precision through the elastic recovery of the material.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent converts the harmful rigid contact into beneficial elastic deformation. The elastic material of the stopper deforms under impact and then recovers, transforming the harmful collision energy into elastic potential energy and then back into kinetic energy in a controlled manner, reducing wear on both the stopper and lens holder while maintaining positioning function.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Measurement precision

If shape memory alloy wires are used to move the lens holder, then actuation precision is improved, but contact sound during movement restriction occurs

Engineering Contradiction:

Improveactuation precisionVSAvoidcontact sound

Core Design Contradiction:

Measurement precisionVSObject-generated harmful factors

Solution Approach 1:

The patent changes the material parameter of the stopper from hard synthetic resin to soft elastic material, transforming the contact characteristics between the stopper and lens holder. This parameter change allows the stopper to deform elastically during contact, absorbing impact energy and reducing contact sound while maintaining positioning precision through the elastic recovery of the material.

Inventive Principle:

Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The device effectively suppresses the generation of abnormal sounds at the stopper, reducing wear and preventing the accumulation of foreign matter due to repeated collisions.

Implementation Method 1

The lens holder includes an elastic portion formed of a material that is softer than that of a synthetic resin material forming the cylindrical portion of the lens holder. The elastic portion includes a movable contact that faces the fixed contact of the stopper so as to be able to contact the fixed contact of the stopper.

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS20250076739A1Lens driving device and camera module

Publication Date: 2025.03.06 ALPS ALPINE CO LTD

AI summary

A lens driving device includes a fixed member including a base member; a lens holder including a cylindrical portion configured to hold a lens body; and a plurality of shape memory alloy wires configured to move the lens holder with respect to the fixed member. The fixed member includes a fixed contact that forms a stopper configured to restrict movement of the lens holder. The lens holder includes an elastic portion formed of a material that is softer than that of a synthetic resin material forming the cylindrical portion of the lens holder. The elastic portion includes a movable contact that faces the fixed contact of the stopper so as to be able to contact the fixed contact of the stopper.