Barcode Reader Light Source Angular Constraint
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Solution Overview
Problem
Current barcode readers cause user blinding due to high-intensity light radiation and suffer from light beam reflections on media surfaces, which deteriorate barcode decoding.
Innovation Solution
The light sources and transparent pane are arranged such that light beams emerge from the outer face at an angle of 35 degrees or less, with light sources positioned in a peripheral zone offset from the reading head and an opaque screen between the light sources and the reading head to minimize reflections and blinding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If high-intensity light sources are used to illuminate the barcode, then the barcode illumination is sufficient for decoding, but the user is blinded by the light radiation
Solution Approach 1:
The patent positions light sources in a peripheral zone rather than centrally, and controls the emission angle to be ≤35 degrees relative to the pane surface. This angular constraint redirects light along the pane surface rather than perpendicular to it, illuminating the barcode effectively while preventing direct light from reaching the user's eyes. The reading head is positioned at a different location and angle, allowing it to detect reflected light from the barcode without being exposed to the direct light source.
2Illumination intensity
If light sources are positioned to illuminate the barcode effectively, then the barcode can be decoded, but light beams are reflected on media surfaces toward the reading head, deteriorating decoding
Solution Approach 1:
The patent creates different illumination conditions for different regions and surfaces. By controlling the light emission angle to be ≤35 degrees relative to the pane surface, the system optimizes illumination for matte surfaces while preventing specular reflections from reaching the reading head. The peripheral positioning of light sources and the angular constraint create localized illumination zones that illuminate the barcode effectively without creating harmful reflections on glossy or plastic media surfaces.
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 configuration reduces user blinding and light reflections, ensuring effective barcode illumination and decoding without compromising passage fluidity.
Implementation Method 1
at least one light source arranged in the inner volume, able to emit beams of light, and configured to illuminate the barcode
Implementation Method 2
a transparent pane fastened in the window of the casing, the pane comprising a plate
Implementation Method 3
the beams emitted by the light sources are reflected on the surface of certain barcode media toward the reading head of the reader
Data Source
AI summary
The present invention relates to a barcode reader comprising a casing, a pane, the pane and casing defining an interior volume; a reading head, and a light source that is able to emit light beams.Each light source and the pane are arranged so that all the transmitted light beams emerge from an outer face of the pane with an angle (α) smaller than or equal to 35 degrees with said outer face. An inner face of the pane includes a peripheral entry face for incident beams, each light source being arranged opposite said peripheral face with its illumination direction perpendicular to said peripheral face, said peripheral face being inclined with respect to a direction normal to a plate of the pane and making up an angle (β) strictly larger than 48.19 degrees with said normal direction.