Mobile Terminal Camera Aperture Control via Lens Separation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Mobile terminal camera modules lack the ability to change the aperture of the diaphragm, which is essential for executing an auto focusing (AF) function effectively, as existing solutions with electric motors face challenges in determining whether to move the motor due to weight considerations.

Innovation Solution

The camera module incorporates a voice coil motor (VCM) actuator and an encoder actuator to drive the diaphragm, allowing for the adjustment of the aperture by positioning the diaphragm and electric motor between the first and second lens assemblies, enabling the auto focusing function without reciprocating the motor, thus overcoming weight-related issues.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If an electric motor is used to change the aperture of the diaphragm, then the aperture can be adjusted, but the weight of the moving components increases making it difficult to execute auto focusing

Engineering Contradiction:
Improveaperture adjustment capabilityVSAvoidweight of motor and diaphragm assembly
Core Design Contradiction:
Adaptability or versatilityVSWeight of moving object

Solution Approach 1:

The patent divides the camera module into separate functional components: the diaphragm assembly is separated from the lens assembly, and the motor is positioned independently on the lens barrel rather than being integrated with the diaphragm. This segmentation allows the diaphragm to remain stationary while still achieving aperture control through optical path adjustment.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a reflective element (mirror or prism) as an intermediary component that redirects light between the diaphragm and the lens. By moving this intermediary element instead of the heavy diaphragm-motor assembly, the system achieves aperture adjustment with minimal moving mass, enabling simultaneous auto focusing operation.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If the diaphragm and electric motor are positioned together to change aperture, then aperture control is achieved, but the heavy weight prevents effective auto focusing execution

Engineering Contradiction:
Improveaperture control functionVSAvoidauto focusing execution efficiency
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent extracts the motor from the diaphragm assembly and positions it separately on the lens barrel. The diaphragm is taken out from the moving components and fixed in position. This extraction eliminates the weight penalty of moving the motor-diaphragm assembly together, allowing the lightweight lens assembly to move freely for auto focusing while the stationary diaphragm maintains aperture control.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the dimension of aperture control from direct mechanical movement of the diaphragm blades to optical path manipulation via a reflective element. By introducing this dimensional shift in the control mechanism, the system achieves aperture adjustment without requiring the heavy diaphragm-motor assembly to move, thereby enabling efficient auto focusing.

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

3Adaptability or versatility

If a traditional motor-driven system is used for aperture adjustment, then aperture can be changed, but the weight limitation prevents efficient auto focusing

Engineering Contradiction:
Improveaperture adjustmentVSAvoidauto focusing operation efficiency
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent replaces the traditional mechanical system where the motor directly drives the diaphragm blades with an optical-mechanical system. The motor now drives a reflective element that optically redirects light to the stationary diaphragm. This substitution eliminates the need for heavy mechanical coupling between the motor and diaphragm, making the system easier to operate for both aperture control and auto focusing.

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

This configuration allows for successful execution of the auto focusing function by moving only the first lens assembly while keeping the diaphragm and electric motor fixed, ensuring the AF function can be performed efficiently without the weight limitations of traditional motor-driven systems.

Implementation Method 1

a voice coil motor (VCM) actuator configured to drive the diaphragm

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Implementation Method 2

an encoder actuator configured to drive the diaphragm

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Implementation Method 3

a first lens unit disposed in the housing and having a plurality of lenses configured to focus light received through the exposed portion of the housing

Methodology Applied
Scientific EffectLight focusing: Lens

Implementation Method 4

a second lens unit disposed in the housing and configured to magnify an image formed by light passing through the first lens unit

Methodology Applied
Scientific EffectImage magnification: Lens

Data Source

PatentEP3255491B1Mobile terminal
Publication Date: 2021.05.05 LG ELECTRONICS INC
  • EP3255491B1 patent drawingFigure 1A
  • EP3255491B1 patent drawingFigure 1B~1C
  • EP3255491B1 patent drawingFigure 2

AI summary

A mobile terminal includes: a terminal body; and a camera module provided at one side of the terminal body, wherein the camera module includes: a first lens assembly; a second lens assembly provided below the first lens assembly; a diaphragm disposed between the first and second lens assemblies, and having its aperture changed; and an actuator disposed close to the first lens assembly, and configured to reciprocate the first lens assembly, wherein the diaphragm includes: a first blade having a through hole therein; a second blade having a through hole therein, and configured to change an aperture of the diaphragm by a relative motion with respect to the first blade; a link member coupled to end parts of the first and second blades, and configured to move the first and second blades by being rotated; and a motor coupled to one side of the link member, and configured to rotate the link member.