Imaging Barcode Reader Color-Separated Aimer Illuminator
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Solution Overview
Problem
Existing barcode readers face challenges in accurately capturing symbol images due to interference from aimer illumination, which disrupts the imaging process and reduces response speed, especially with 2D symbols of poor quality or high density.
Innovation Solution
The use of different colors or frequency bands for aimer patterns and image capture illumination allows for simultaneous aiming and symbol decoding by bandwidth-separating the aimer patterns from the image capture illumination, either through color blocking filters or software processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the aimer illumination is turned on to guide the scanner alignment, then the scanner can be properly aimed at the symbol, but the aimer pattern becomes visible to the imager and creates noise that disrupts symbol interpretation
Solution Approach 1:
The patent segments the illumination function into two distinct components: an aimer light source for alignment guidance and an illuminator light source for symbol illumination. This segmentation allows each component to operate independently with optimized characteristics, enabling the aimer to remain on during imaging without interfering with symbol capture.
Solution Approach 2:
The patent applies different spectral characteristics to different parts of the illumination system. The aimer emits light at a first wavelength (e.g., infrared or ultraviolet) that is distinct from the illuminator's wavelength, creating local quality differences that enable the imager to distinguish between aimer patterns and symbol reflections.
2Reliability
If the aimer illumination is turned off during image capture to eliminate noise, then symbol interpretation accuracy improves, but the scanner response speed decreases due to the need to switch states
Solution Approach 1:
The patent enables continuous operation of the aimer illumination throughout the entire imaging process, eliminating the need for on-off switching. The imager is configured to selectively ignore the aimer's wavelength while capturing the symbol, allowing the aimer to provide continuous alignment guidance without interrupting the scanning workflow.
3Reliability
If the aimer intensity is reduced to minimize interference with symbol capture, then image noise decreases, but the visibility of the aimer pattern for alignment guidance deteriorates
Solution Approach 1:
The patent employs wavelength-specific detection capabilities where the imager is optimized to detect the illuminator's wavelength while being insensitive to the aimer's wavelength. This allows the aimer to operate at high intensity for excellent alignment visibility without contributing noise to the symbol capture image.
4Reliability
If a color blocking filter is added to block the aimer pattern from the imager, then symbol interpretation accuracy improves, but the device complexity increases
Solution Approach 1:
The patent replaces physical optical filtering mechanisms with electronic or software-based wavelength discrimination. The imager uses digital signal processing or spectral filtering algorithms to selectively reject the aimer's wavelength, eliminating the need for additional physical filters and reducing mechanical complexity.
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 enables continuous aimer illumination without degrading symbol decoding performance, allowing for faster and more accurate reading of machine-readable symbols, including 2D codes with high density or poor print quality.
Implementation Method 1
The color blocking filter is configured to block the first wavelength from reaching the image sensor
Implementation Method 2
an illuminator to provide continuous illumination at a second wavelength
Data Source
AI summary
A scanner for machine-readable symbols, such as barcodes and two-dimensional matrix symbols, employs at least two different light frequencies (colors). The first frequency supports accurate aiming of the scanner at a symbol. The second frequency supports illumination of a machine-readable symbol so that the reflected illumination light can be read at the second frequency by the scanner's optical imaging element. Employing two different light frequencies enables both aiming and scanning to occur simultaneously, while the aiming process does not interfere with the scanning process. It enables the aiming frequency to be used for additional purposes, such as providing signaling to a user of the scanner. In an embodiment, two distinct light sources are used in the scanner to provide the different light frequencies. In an embodiment, various color filters are employed to separate and distinguish light frequencies. In an embodiment, signal processing may be employed to digitally distinguish multiple separate frequencies in light reflected from the symbol.