Camera Actuator With Ball-Guided Lens Movement for Ultra-Slim OIS

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Solution Overview

Problem

Existing camera actuators face challenges in ultra-slim and ultra-small devices due to space constraints for image stabilization (OIS) and magnetic field interference between OIS and other functions, limiting lens size and movement, especially in high-resolution cameras.

Innovation Solution

A camera actuator design that moves first and second lens assemblies relative to each other, utilizing balls on the actuator's side surface for improved reliability and driving force, with electrical connection through these balls, and separate coils and magnets to prevent magnetic interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an actuator for OIS is disposed around the lens to enable image stabilization, then the lens can be tilted or moved for correcting image shake, but the space required for arranging the actuator limits the lens size and overall device dimensions in ultra-slim and ultra-small cameras

Engineering Contradiction:
Improveimage stabilization functionVSAvoidlens size
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The patent changes the movement dimension from traditional lateral tilting to longitudinal movement along the optical axis. The lens assembly moves forward and backward along the Z-axis direction rather than tilting sideways, which eliminates the need for large lateral space while maintaining OIS functionality. This dimensional change allows the lens to achieve stabilization without increasing device width or height.

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

Solution Approach 2:

The patent divides the actuator system into separate functional components: a voice coil motor for driving the lens assembly along the optical axis, and linear ball-guided rails for guiding the movement. This segmentation allows each component to be optimized independently and arranged in a space-efficient manner along the optical axis, reducing the overall volume required for the OIS mechanism.

Inventive Principle:
Principle #1Segmentation

2Illumination intensity

If the lens size is increased to increase the amount of received light in high-resolution cameras, then more light can be captured, but the space occupied by the OIS actuator limits the maximum lens size

Engineering Contradiction:
Improveamount of received lightVSAvoidspace occupied by actuator
Core Design Contradiction:
Illumination intensityVSVolume of moving object

Solution Approach 1:

By changing the OIS mechanism from lateral tilting to longitudinal movement along the optical axis, the patent frees up lateral space that can be used to accommodate larger lens elements. The lens assembly can now be sized based on light-gathering requirements rather than being constrained by the lateral space needed for traditional OIS actuators.

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

3Volume of moving object

If OIS magnets and AF or zoom magnets are disposed close to each other to save space, then the device becomes more compact, but magnetic field interference occurs between the magnets

Engineering Contradiction:
Improvedevice compactnessVSAvoidmagnetic field interference
Core Design Contradiction:
Volume of moving objectVSObject-generated harmful factors

Solution Approach 1:

The patent extracts the OIS magnet system from the traditional lateral arrangement and repositions it along the optical axis, separating it spatially from AF or zoom magnets. The OIS magnet is disposed at a position where it interacts with the voice coil motor along the Z-axis, while AF/zoom magnets are positioned elsewhere in the optical path, eliminating magnetic field interference while maintaining device compactness.

Inventive Principle:
Principle #2Taking out (Extraction)

4Reliability

If traditional OIS actuators are used that require lateral tilting space, then image stabilization can be achieved, but the device cannot be made ultra-slim and ultra-small due to space constraints

Engineering Contradiction:
Improveimage stabilization functionVSAvoiddevice thickness
Core Design Contradiction:
ReliabilityVSLength of stationary object

Solution Approach 1:

The patent fundamentally changes the OIS mechanism from lateral tilting (X-Y axis rotation) to longitudinal movement (Z-axis translation). The lens assembly moves forward and backward along the optical axis to achieve stabilization, which only requires space along the thin dimension of the device rather than lateral space, enabling ultra-slim form factors.

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

Solution Approach 2:

The patent replaces the traditional mechanical tilting mechanism with an electromagnetic voice coil motor system that drives linear movement along the optical axis. This substitution eliminates the need for complex mechanical tilting joints and reduces the lateral space requirement, allowing the device to achieve ultra-slim thickness while maintaining effective image stabilization.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

Enables efficient OIS in ultra-slim, ultra-small, high-resolution cameras without increasing size, ensuring stable tilting in X and Y axes without magnetic interference, and securing sufficient light while reducing power consumption.

Implementation Method 1

a first ball moving along a rail to drive the first lens assembly

Methodology Applied
Scientific EffectBall Bearing: Ball Bearing

Implementation Method 2

first and second voice coil motors coupled to the lens

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Data Source

PatentEP4152740B1Camera actuator and camera device including same
Publication Date: 2025.10.22 LG INNOTEK CO LTD
  • EP4152740B1 patent drawingFigure 1~2
  • EP4152740B1 patent drawingFigure 3~4
  • EP4152740B1 patent drawingFigure 5~6

AI summary

An embodiment of the present invention provides a camera actuator comprising: a base including a first side wall and a second side wall corresponding to the first side wall; a guide part disposed adjacent to at least one of the first side wall and the second side wall; a first lens assembly and a second lens assembly that is movable relative to the first lens assembly in the first lens assembly; a driving part for moving the first lens assembly and the second lens assembly; and a first ball disposed at an upper side portion of the first lens assembly and a second ball disposed at a lower side portion thereof, wherein the first lens assembly moves along the guide part through the first ball and the second ball.