Strobe Illumination Synchronization for Motion Blur Reduction

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Precision machine vision inspection systems face challenges in accurately detecting edges due to sub-optimal illumination direction, leading to edge artifacts and reduced measurement repeatability, especially when workpieces are in motion, requiring improvements in illumination control to minimize blurring and maintain accuracy.

Innovation Solution

The implementation of a system with a transient light source, such as a Xenon flashlamp, and a spatial light modulator (SLM) that controls light distribution through multiple channels, allowing for precise adjustment of illumination intensity and direction, synchronized with camera exposure to optimize image capture during motion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a transient light source is used to illuminate a workpiece during motion, then productivity increases, but edge detection accuracy deteriorates due to motion blur

Engineering Contradiction:

Improveworkpiece inspection throughputVSAvoidedge detection accuracy

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The patent applies periodic action by using a strobe light that emits light in periodic pulses synchronized with the camera exposure. The strobe light flashes at specific intervals to illuminate the moving workpiece only during the brief exposure moment, creating freeze-frame effect that eliminates motion blur while allowing continuous workpiece motion for high productivity

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The patent implements preliminary action by precisely timing the strobe light flash to occur immediately before or during the camera exposure window. The illumination is prepared and activated in advance of the actual image capture moment, ensuring optimal lighting conditions are established before the measurement process begins

Inventive Principle:

Principle #10Preliminary action

2Measurement precision

If illumination intensity is increased to improve edge detection, then measurement precision improves, but harmful shadows and over-exposure increase

Engineering Contradiction:

Improveedge detection accuracyVSAvoidlighting artifacts

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by using multiple independent light sources positioned at different locations around the workpiece, each providing illumination from a specific angle. The system selectively activates only the light sources needed for the current inspection task, providing locally optimized illumination that highlights specific edge features without creating harmful shadows from unnecessary directions

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent implements parameter changes by dynamically adjusting the intensity and duration of each light source based on the inspection requirements. The system varies illumination parameters such as flash duration, intensity level, and activation timing to achieve optimal edge contrast without over-exposure or shadow artifacts

Inventive Principle:

Principle #35Parameter changes

3Measurement precision

If multiple light sources are used to improve illumination coverage, then measurement precision improves, but device complexity increases

Engineering Contradiction:

Improveillumination control accuracyVSAvoidillumination system complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies universality by designing a modular illumination system where multiple light sources share common control electronics, mounting structures, and synchronization mechanisms. Each light source can perform multiple functions depending on which ones are activated, and the system as a whole provides versatile illumination capabilities while avoiding redundant components that would increase complexity

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 enhances edge detection accuracy and measurement repeatability by providing consistent and controlled illumination, even during workpiece motion, thereby increasing productivity and inspection throughput.

Implementation Method 1

The illumination source emits light of one or more visible or invisible wavelengths of radiation suitable for imaging the workpiece, as a transient flash or pulse to the workpiece in response to a lamp trigger

Methodology Applied

Scientific EffectStrobe illumination:

Data Source

PatentUS8045002B2Systems and methods for controlling strobe illumination

Publication Date: 2011.10.25 MITUTOYO CORP

AI summary

Various exemplary embodiments may provide systems and methods for strobe illumination of a workpiece. The systems may include an illumination source, an image acquisition device and a control system. The illumination source may emit visible, UV, or near-IR light as a transient flash to the workpiece, the transient flash occurring in response to a lamp trigger. The illumination source may emit the light at an illumination intensity that rises from a begin threshold to a peak and afterwards diminishes to an end threshold during a flash duration. The image acquisition device may capture the light associated with the workpiece for an exposure duration starting from an exposure trigger. The control system may control the illumination source and the image acquisition device to synchronize the lamp trigger so that the exposure duration ends during the flash duration, such that a remaining portion of the flash does not affect the image exposure.