Prism Drive Device with Repulsive Magnetic Support

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Solution Overview

Problem

Existing camera modules face challenges in reducing product size while maintaining zooming functionality, particularly when using prisms for size reduction.

Innovation Solution

A prism driving device with a housing, a mover, a prism, a first magnet, a coil, and a guide part, where the first magnet comprises multiple units to tilt the prism and mover electromagnetically, and a second magnet on the housing provides repulsive force for support.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If a prism is used to reduce product size while maintaining zooming functionality, then the product size is reduced, but the device complexity increases due to the need for precise electromagnetic tilting mechanisms

Engineering Contradiction:
Improveproduct sizeVSAvoiddevice complexity
Core Design Contradiction:
Volume of moving objectVSDevice complexity

Solution Approach 1:

The first magnet is divided into multiple magnet units (first, second, third, fourth magnet units) that are spatially separated and independently controlled. Each magnet unit interacts with corresponding coil units to provide independent electromagnetic forces for tilting the prism along different axes, enabling complex zooming movements through coordinated control of segmented magnetic components

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The electromagnetic interaction system serves multiple functions: it provides both the tilting force for zooming operations and the supporting force to hold the prism at various positions. The same magnet-coil pairs that generate tilting moments also provide the primary support force, eliminating the need for separate mechanical support structures

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

2Adaptability or versatility

If electromagnetic interaction is used to tilt the prism for zooming, then zooming functionality is achieved, but the manufacturing precision requirements increase due to the need for precise magnet and coil positioning

Engineering Contradiction:
Improvezooming functionalityVSAvoidmagnet and coil positioning precision
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

Different regions of the prism assembly have locally optimized magnetic field interactions. The first and second magnet units are positioned to provide tilting force around a first axis, while the third and fourth magnet units are positioned to provide tilting force around a second axis. Each local region has its own dedicated coil units for precise control, allowing independent adjustment of tilting angles around different axes without affecting other regions

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The magnetic field interaction extends into the optical axis direction (first axial direction), with magnet units and coil units arranged at different positions along this dimension. This three-dimensional arrangement allows the electromagnetic force to act effectively at a distance, providing both tilting and support functions while accommodating the optical path requirements of the zooming system

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 reduces product size by allowing precise tilting of the prism and mover, enabling efficient zooming functionality within a compact form factor.

Implementation Method 1

the first and second magnet units are configured to tilt the prism and the mover with respect to a first axis through electromagnetic interaction with the first and second coils

Methodology Applied
Scientific EffectElectromagnetic interaction: Lorentz Force

Implementation Method 2

the mover and the guide part are supported by the housing by a repulsive force between the first magnet and the second magnet

Methodology Applied
Scientific EffectMagnetic repulsion: Ion Repulsion/Attraction

Data Source

PatentEP4047404B1Prism drive device
Publication Date: 2025.06.11 LG INNOTEK CO LTD
  • EP4047404B1 patent drawingFigure 1
  • EP4047404B1 patent drawingFigure 2
  • EP4047404B1 patent drawingFigure 3

AI summary

A prism drive device of the present invention comprises: a housing; a mover disposed in the housing; a prism disposed in the mover; a first magnet disposed in the mover; a coil disposed in the housing; a guide part disposed between the housing and the mover and configured to guide the tilting of the mover; and a second magnet disposed in the housing and facing the first magnet, wherein the first magnet and the second magnet face each other with the same pole.