Dual Camera Autofocus Wobble Prevention via Segmented Lens Control

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Solution Overview

Problem

The frequent movement of camera lenses during automatic focus (AF) leads to a wobbling phenomenon in the field of view (FoV) displayed on electronic devices, such as smartphones, which affects image sharpness and user experience.

Innovation Solution

Implementing a dual-camera system where a sub-camera module performs AF operations and provides data for the main camera module, allowing the processor to suspend lens movement until a stable focus direction is achieved, thereby preventing image wobble and enhancing AF speed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the lens moves frequently during AF to achieve focus, then the AF function can adjust focus dynamically, but the field of view wobbles in the displayed image

Engineering Contradiction:
ImproveAF functionVSAvoidfield of view stability
Core Design Contradiction:
Ease of operationVSStability of the object's composition

Solution Approach 1:

The patent divides the camera system into two separate modules: a first camera module dedicated to AF operations and a second camera module dedicated to capturing stable images for display. This segmentation allows the lens in the first module to move freely for focus adjustment while the second module maintains a fixed field of view for stable image capture, thereby resolving the contradiction between AF flexibility and image stability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary mechanism where the processor receives AF data from the first camera module and uses it to control the lens movement of the second camera module. This intermediary approach allows the system to benefit from AF functionality while maintaining image stability by mediating between the two camera modules' operations.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If the lens moves continuously during AF, then focus adjustment is achieved, but image quality deteriorates due to wobbling

Engineering Contradiction:
ImproveAF speedVSAvoidimage sharpness
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

By segmenting the camera system into two independent modules with separate lens assemblies, the patent enables the first module to perform rapid AF movements without affecting the second module's image capture quality. Each module can optimize its lens movement independently, ensuring both high AF speed and image sharpness.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary AF operations using the first camera module before capturing final images with the second camera module. This preliminary action allows the system to determine focus requirements in advance, enabling faster and more accurate focusing while maintaining image quality during the actual image capture.

Inventive Principle:
Principle #10Preliminary action

3Device complexity

If a single camera module performs both AF and image capture, then device complexity is reduced, but image wobble occurs during AF operations

Engineering Contradiction:
Improvecamera module structureVSAvoiddisplayed image stability
Core Design Contradiction:
Device complexityVSStability of the object's composition

Solution Approach 1:

The patent applies segmentation by creating two separate camera modules: one specialized for AF operations and another for stable image capture. This segmentation resolves the image wobble problem by isolating the lens movement function from the image capture function, allowing each to operate independently without interfering with the other.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements multi-functionality by having the processor serve multiple functions: it processes images from the second camera module for display while simultaneously controlling the lens movement of the first camera module for AF operations. This universal approach allows a single processing system to manage multiple camera functions without requiring separate dedicated hardware for each function.

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

Data Source

PatentEP3343899B1Electronic device for performing autofocus
Publication Date: 2021.09.01 SAMSUNG ELECTRONICS CO LTD
  • EP3343899B1 patent drawingFigure 1
  • EP3343899B1 patent drawingFigure 2
  • EP3343899B1 patent drawingFigure 3

AI summary

An electronic device is provided. The electronic device includes a first camera module including a first lens set, a second camera module including a second lens set, and a processor connected to the first camera module and a second camera module. The processor is configured to move the first lens focus on a subject, resulting in an auto focus (AF) value and an image obtained by the first camera module, evaluate reliability of the AF value, based on the reliability of the AF value, calculate a movement parameter of the second lens set, corresponding to a movement parameter of the first lens set, and move the second lens set depending on the calculated movement parameter.