Alternating Light Source Imaging Module for Specular Reflection Reduction
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Solution Overview
Problem
Existing imaging systems face challenges with specular reflections from glossy or highly reflective surfaces, which can overload image sensors and degrade reading performance, and current methods to mitigate this issue reduce the frame rate and blink rate, making them unsuitable for fast reading applications and uncomfortable for operators.
Innovation Solution
The imaging module alternately energizes and deenergizes light sources during successive frames, subdividing each frame into subframes to capture image portions with reduced specular reflection, and pulsing light sources at a rate equal to or exceeding the frame rate to minimize glare and discomfort.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If illumination light sources are used to increase return light capture, then reading performance in dimly lit environments is improved, but specular reflections are generated that overload the image sensor and degrade reading performance
Solution Approach 1:
The patent applies periodic action by alternately energizing and deenergizing different illumination light sources during successive frames. The controller energizes a first light source during odd-numbered frames and a second light source during even-numbered frames, creating a periodic illumination pattern that prevents specular reflections from overloading the image sensor while maintaining adequate illumination for reading.
2Reliability
If multiple light sources are alternately energized to mitigate specular reflection, then reading performance is improved, but frame rate is reduced because it takes two frames to produce a composite image
Solution Approach 1:
The patent maintains continuity of useful action by capturing useful image data in every frame. Unlike conventional methods that discard frames captured with the 'wrong' light source, this patent processes and combines data from all frames, ensuring that each frame contributes to the final reading result and maintaining a high frame rate.
3Measurement precision
If light sources are pulsed at half the frame rate to mitigate specular reflection, then reading accuracy is improved, but operator comfort deteriorates due to annoying blinking light patterns
Solution Approach 1:
The patent changes the parameter of light source pulsing frequency to match the frame rate instead of being at half the frame rate. By energizing light sources at each frame transition rather than every other frame, the blinking occurs at a frequency (frame rate) that is less visually annoying to operators while still maintaining the ability to mitigate specular reflections through alternating light source activation.
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 approach effectively mitigates specular reflections while maintaining or increasing frame and blink rates, enhancing reading performance and operator comfort by reducing annoying light patterns.
Implementation Method 1
capturing return light scattered and/or reflected from the target
Implementation Method 2
capturing return light scattered and/or reflected from the target
Implementation Method 3
The illumination light is typically emitted from illumination light sources, e.g., light emitting diodes (LEDs)
Implementation Method 4
such glossy, reflective surfaces promote mirror-like, specular reflections
Data Source
AI summary
One light source is energized and another light source is simultaneously deenergized during one frame of an imager that captures return light from an illuminated target as a first image portion having a first target portion. The other light source is energized and the one light source is simultaneously deenergized during another frame to capture the return light from the illuminated target as a second image portion having a second target portion. Either the target portions are combined to form the target to be read, or the image portions are combined to form a composite image from which the target is read.