Reflective Member Driving Device for Compact OIS Actuator

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Solution Overview

Problem

Existing camera devices face challenges in implementing optical image stabilization (OIS) due to space constraints in ultra-slim and subminiature camera modules, and the need for larger lenses to increase light intake is limited by actuator size. Additionally, magnetic field interference and weight reduction issues arise from maintaining the position of reflective members.

Innovation Solution

A reflective member driving device that utilizes a housing, a holder, a reflective member, a moving plate, a coil, and a magnet to implement OIS through tilting of the reflective member. This device also employs an elastic member to maintain contact between the moving plate and the holder, reducing the need for magnets and minimizing space requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If a magnet is added to maintain the position of the reflective member, then the position stability is improved, but magnetic field interference and weight increase

Engineering Contradiction:
Improveposition stabilityVSAvoidmagnetic field interference
Core Design Contradiction:
Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The patent removes the magnet from the system entirely, replacing it with an elastic member (spring) to maintain contact between the moving plate and holder. This extraction eliminates the magnetic field interference problem while achieving the same position stability function through mechanical elasticity.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The elastic member acts as an intermediary between the moving plate and holder, providing the necessary contact force without requiring a magnet. This mediator achieves position stability through elastic deformation rather than magnetic attraction, avoiding harmful magnetic field effects.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Illumination intensity

If the size of the lens is increased to increase light intake, then the light receiving amount is improved, but the space occupied by the actuator limits further enlargement

Engineering Contradiction:
Improvelight receiving amountVSAvoidactuator space
Core Design Contradiction:
Illumination intensityVSArea of stationary object

Solution Approach 1:

The patent combines the OIS and AF functions into a single integrated actuator structure. The moving plate serves dual purposes: it tilts for OIS while also moving axially for AF. This merging allows the system to achieve both functions within a compact space, enabling larger lens diameters without proportionally increasing actuator volume.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The moving plate is designed with multi-functionality, serving both as the OIS reflective member carrier and the AF adjustment mechanism. This universal component performs multiple functions (tilting for stabilization, axial movement for focus) within a single structure, maximizing space efficiency and allowing larger lens apertures.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Stability of the object's composition

If additional components are added to maintain reflective member position, then the position stability is improved, but the device complexity increases

Engineering Contradiction:
Improveposition stabilityVSAvoidstructure complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent merges the position maintenance function with the existing moving plate structure. The elastic member is integrated into the holder assembly, and the moving plate itself serves as the position-sensitive component. This merging eliminates the need for separate positioning mechanisms, reducing overall device complexity while maintaining stability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The elastic member provides self-regulating position maintenance through its inherent elastic properties. When the moving plate moves, the elastic member deforms and generates a restoring force that automatically returns the plate to its neutral position. This self-service mechanism eliminates the need for complex active control systems or additional positioning components.

Inventive Principle:
Principle #25Self-service

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 solution enables a compact camera actuator that provides both driving and suction forces with a single magnet, prevents lubricating member collisions, and is applicable to ultra-slim, subminiature, and high-resolution cameras. It also reduces power consumption and enhances OIS performance by optimizing the placement of elastic members relative to the OIS coil.

Implementation Method 1

an elastic member connecting the housing and the holder, wherein the moving plate is pressed between the holder and the housing by the elastic member

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a coil and a magnet for moving the holder against the housing

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Data Source

PatentEP4542298A1Reflective member driving device, camera device, and optical instrument
Publication Date: 2025.04.23 LG INNOTEK CO LTD
  • EP4542298A1 patent drawingFigure 1~2
  • EP4542298A1 patent drawingFigure 3~4
  • EP4542298A1 patent drawingFigure 5

AI summary

The present embodiment relates to a reflective member driving device comprising: a housing; a holder being disposed inside the housing; a reflective member being disposed in the holder; a moving plate being disposed between the housing and the holder; a coil and a magnet for moving the holder against the housing; and an elastic member connecting the housing and the holder, wherein the moving plate is disposed in a first portion of the housing, and wherein the elastic member is disposed at an opposite side of the moving plate with respect to the first portion of the housing and is directly coupled to the holder.