Camera Module Resonance Coil Lens Position Detection

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Solution Overview

Problem

Existing camera modules face challenges with position detection accuracy, particularly as lens movement distance increases, and reliability issues due to environmental factors and heat generation. Additionally, they struggle with friction torque during zooming, lens alignment, and magnetic field interference.

Innovation Solution

A camera module design that incorporates a position detection sensor with improved linearity and hysteresis, a separable base and rail design for enhanced assembly and reliability, and a resonance coil system to minimize friction torque and prevent lens misalignment. This design also includes a substrate with resonance coils to accurately detect lens movement and maintain optical alignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a Hall sensor is used to detect lens position, then position detection is possible, but linearity decreases as lens movement distance increases and reliability is poor due to heat

Engineering Contradiction:

Improveposition detection accuracyVSAvoidsensor reliability

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent replaces the Hall sensor (magnetic field-based detection) with a resonance coil system that uses electromagnetic resonance. The resonance coil detects lens position through changes in resonance frequency or impedance caused by the position of conductive elements on the lens assembly, eliminating the linearity and heat reliability issues of Hall sensors.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the detection parameter from magnetic field strength (Hall sensor) to resonance frequency or impedance characteristics. The resonance coil system measures position by detecting changes in electrical parameters (resonance frequency, impedance) that vary with lens position, providing better linearity and heat stability.

Inventive Principle:

Principle #35Parameter changes

2Ease of manufacture

If the lens barrel and mover are integrated, then assembly is simpler, but design flexibility and assembly facilitation are reduced

Engineering Contradiction:

Improveassembly simplicityVSAvoiddesign flexibility

Core Design Contradiction:

Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent divides the lens assembly into separable components: the lens barrel and the mover. The lens barrel contains the optical elements while the mover contains the driving mechanism. This segmentation allows independent optimization of each component's design and facilitates easier assembly, disassembly, and manufacturing.

Inventive Principle:

Principle #1Segmentation

3Adaptability or versatility

If zooming is implemented, then magnification adjustment is possible, but friction torque is generated during lens movement

Engineering Contradiction:

Improvezooming capabilityVSAvoidfriction torque

Core Design Contradiction:

Adaptability or versatilityVSForce

Solution Approach 1:

The patent replaces traditional mechanical contact-based zoom mechanisms with a resonance-driven electromagnetic system. The resonance coil generates electromagnetic forces that move the lens assembly through zoom positions without mechanical friction, eliminating friction torque while maintaining zooming capability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

4Reliability

If lens movement is increased for wider correction range, then OIS correction range improves, but position detection linearity decreases

Engineering Contradiction:

ImproveOIS correction rangeVSAvoidposition detection linearity

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The patent changes the detection method to use resonance frequency or impedance parameters that maintain linear relationships even over larger movement distances. The resonance coil system provides consistent detection linearity across the full OIS correction range through electromagnetic field interactions that scale linearly with position.

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 proposed camera module achieves improved position detection accuracy, reduced friction torque during zooming, enhanced reliability in various environments, and minimized lens misalignment, leading to improved image quality and reduced manufacturing costs.

Implementation Method 1

the substrate includes a resonance coil disposed in a region facing the lower surface of the lens assembly and overlapping at least a part of the conductor

Methodology Applied

Scientific EffectResonance: Resonance

Implementation Method 2

the lens assembly includes a conductor disposed under a lower surface thereof, and wherein the substrate includes a resonance coil disposed in a region facing the lower surface of the lens assembly

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentUS12294777B2Camera module and camera device comprising same

Publication Date: 2025.05.06 LG INNOTEK CO LTD

AI summary

A camera module includes base; a guide portion disposed on an inner side of the base; a lens assembly moving along the guide portion; and a substrate disposed on an outer side of the base. The lens assembly includes a conductor disposed under a lower surface thereof. The substrate includes a resonance coil disposed in a region facing the lower surface of the lens assembly and overlapping at least a part of the conductor in a direction perpendicular to an optical axis direction in response to movement of the lens assembly.