Autofocus Controller Using Saturated Object Area Trends

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing image capturing devices face challenges in detecting an in-focus position with sufficient speed and accuracy, particularly in low illumination environments with spot light.

Innovation Solution

The image capturing device includes a lens, a lens driver, an image sensor, and a focus controller. The focus controller detects saturated objects in multiple image regions, selects regions with consistent feature changes as it adjusts the focus position, and minimizes the area of saturated objects to determine the in-focus position.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If contrast detection method is used for autofocus, then calculating speed improves, but detection precision of in-focus position deteriorates in low illumination environments

Engineering Contradiction:

Improvecalculating speedVSAvoiddetection precision

Core Design Contradiction:

SpeedVSMeasurement precision

Solution Approach 1:

The image is divided into multiple regions, and saturated objects are detected in each region separately. This segmentation allows the system to focus on specific high-contrast areas rather than processing the entire image, improving both speed and precision in low illumination environments.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies different processing strategies to different regions by detecting saturated objects (pixels exceeding threshold values) in specific regions. Regions containing saturated objects are identified and processed differently from other regions, allowing local optimization of focus detection based on actual image content characteristics.

Inventive Principle:

Principle #3Local quality

2Illumination intensity

If autofocus operation is performed in low illumination environments with spot light, then imaging capability is maintained, but detection accuracy of in-focus position deteriorates due to saturated areas

Engineering Contradiction:

Improvelow illumination environment capabilityVSAvoiddetection accuracy

Core Design Contradiction:

Illumination intensityVSMeasurement precision

Solution Approach 1:

The patent converts the harmful effect of saturated areas (caused by spot light in low illumination) into a useful feature. By detecting saturated objects and analyzing their area changes during focus adjustment, the system uses the saturation phenomenon itself as a focus detection metric, turning an adverse condition into a beneficial indicator for determining in-focus position.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The system monitors changes in the area of saturated objects as the focus position is adjusted. By tracking how the area of saturated regions changes with focus distance, the system establishes a relationship between saturation area variation and focus state, enabling accurate focus detection even when traditional contrast methods fail due to low illumination.

Inventive Principle:

Principle #35Parameter changes

3Productivity

If traditional autofocus methods are used, then general imaging is achieved, but speed and accuracy of in-focus detection are insufficient

Engineering Contradiction:

Improveautofocus speedVSAvoidin-focus detection accuracy

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The system performs preliminary detection of saturated objects in multiple regions before conducting the full focus search. By pre-identifying regions with saturated objects and calculating their initial areas, the system prepares focus detection data in advance, enabling faster and more accurate focus adjustment by comparing area changes during the autofocus operation.

Inventive Principle:

Principle #10Preliminary action

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 solution enables the image capturing device to detect the in-focus position with improved speed and accuracy, even in low illumination environments with spot light, by effectively managing saturated areas and feature changes.

Implementation Method 1

an image sensor configured to detect light passed through the lens

Methodology Applied

Scientific EffectPhotoelectric Effect: Photoelectric Effect

Data Source

PatentUS12282204B2Image capturing device for performing autofocus

Publication Date: 2025.04.22 HANWHA VISION CO LTD

AI summary

An image capturing device includes a lens, a lens driver configured to change a focus position by moving the lens, an image sensor configured to detect light passed through the lens, and a focus controller configured to control, based on an image generated by the image sensor, the lens driver to adjust the focus position. The focus controller is further configured to: monitor a feature change of a saturated object having an intensity greater than or equal to a threshold value, in each of a plurality of regions of an image, by adjusting the focus position; and adjust the focus position based on a trend of the feature change of the saturated object while the focus position is changed in a direction.