Synchronized Visible-Light Defect Inspection Under Pose and Lighting Variation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Industrial imaging systems face challenges in accurately detecting defects due to part and image sensor pose variations, material property variations, image background variations, and ambient or controlled lighting variations, which impact the effectiveness of classification algorithms.

Innovation Solution

A method and system that utilize a controlled lighting device to project a predefined dynamic lighting pattern onto an object, capture image frames, process them to generate intensity images, and apply machine learning-based classification to assign defect labels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional imaging systems are used for defect detection, then the system structure is simple, but the inspection accuracy is reduced due to part pose variations, material property variations, lighting variations, and background variations

Engineering Contradiction:
Improveinspection accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent employs dynamic lighting patterns that change over time to illuminate the object from multiple virtual angles. The lighting device projects sequential lighting patterns that dynamically interact with surface defects, enabling the detection system to capture defect information under varying lighting conditions without requiring physical movement of the object or camera, thus improving inspection accuracy while maintaining relatively simple system structure.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The lighting device projects a series of periodic lighting patterns onto the object surface. By capturing images during these periodic lighting variations, the system can differentiate between static background elements and dynamic defect reflections, thereby improving defect detection accuracy without significantly increasing system complexity.

Inventive Principle:
Principle #19Periodic action

2Measurement precision

If dynamic lighting patterns are projected to improve defect detection, then inspection accuracy is enhanced, but the complexity of lighting control increases

Engineering Contradiction:
Improvedefect detection accuracyVSAvoidlighting control complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The lighting device divides the illumination into multiple discrete lighting patterns, each designed to highlight specific defect characteristics. By segmenting the lighting into distinct patterns that can be sequentially projected, the system achieves comprehensive defect detection while maintaining manageable control complexity through modular pattern design.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system changes lighting parameters such as intensity, angle, and pattern configuration to optimize defect detection. By varying these parameters in a controlled manner, the system enhances defect visibility and detection accuracy without requiring overly complex lighting control mechanisms, as the parameter changes follow predefined patterns.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If multiple image frames are captured and processed to generate intensity images, then defect detection capability is improved, but the processing time and computational load increase

Engineering Contradiction:
Improvedefect detection capabilityVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system extracts only the relevant intensity information from multiple captured image frames by comparing pixel intensities across frames. This extraction approach focuses computational resources on calculating intensity differences and variations that indicate defects, rather than processing all image data, thereby improving defect detection capability while reducing overall processing time.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system performs preliminary processing on captured image frames by immediately calculating intensity values and comparing them against reference patterns. This preliminary action prepares the data in advance for final defect analysis, reducing the computational burden during the critical detection phase and minimizing overall processing time.

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

Enhances inspection accuracy by minimizing the impact of variations and effectively detecting defects in manufactured parts, including both surface and internal flaws.

Implementation Method 1

The controlled lighting device is configured to generate a sequence of varying images for illuminating the object

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentUS12505527B2System and method for defect detection using visible light cameras with synchronized lighting
Publication Date: 2025.12.23 EIGEN INNOVATIONS
  • US12505527B2 patent drawing
  • US12505527B2 patent drawing
  • US12505527B2 patent drawing

AI summary

System and method that includes: projecting a dynamic lighting pattern from a controlled lighting device towards a manufactured object; capturing a light response of the object, over an inspection period, to the dynamic lighting pattern and generating a set of image frames representing the captured lighting response; processing the set of image frames to generate an intensity image that is based on intensity information across a plurality of the image frames; assigning a quality label based on the generated intensity image.