Multi-Color LED Illumination for Barcode Scanners
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Solution Overview
Problem
Conventional barcode scanners using white phosphor-based LEDs for illumination have low energy efficiency and high production costs due to the need for additional components like optical filters to improve watermark reflectance signal strength, and they often use single color illumination which limits color detection capabilities.
Innovation Solution
A barcode scanner system utilizing multiple color light sources, such as red, blue, and green LEDs, with a controller to adjust the intensity and duty cycles of each LED to produce a white illumination beam, minimizing visibility and distraction while enhancing image data quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If white phosphor-based LED is used for illumination, then white light is produced, but energy efficiency decreases and production cost increases
Solution Approach 1:
The patent segments the white light generation into multiple independent color LED sources (red, green, blue) instead of using a single phosphor-converted LED. Each color LED operates independently and can be controlled separately, allowing the system to produce white light through additive color mixing while maintaining higher energy efficiency and reducing the need for additional components like optical filters.
2Measurement precision
If optical filter is added to improve watermark reflectance signal strength, then signal loss is reduced, but device complexity and production cost increase
Solution Approach 1:
The patent makes the illumination system multi-functional by using adjustable color LED combinations that can serve multiple purposes: reading barcodes, reading watermarks, and adapting to different lighting conditions. The same multi-color LED array that provides white light for general illumination can also be tuned to specific wavelengths optimal for watermark detection, eliminating the need for separate optical filters while maintaining measurement precision.
3Device complexity
If single color illumination is used, then device complexity is reduced, but color detection capability is limited
Solution Approach 1:
The patent implements dynamic control of the multi-color LED illumination system, allowing the controller to adjust the intensity and wavelength composition of each color LED in real-time based on the scanning requirements. This dynamic adaptability enables the system to switch between single-color mode (for simplicity) and multi-color mode (for enhanced color detection capability), resolving the contradiction between device complexity and versatility.
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
The system achieves improved energy efficiency and cost-effectiveness by generating a white illumination beam that enhances the reading of barcodes and watermarks with reduced signal loss and increased color detection capabilities, compared to traditional single-color or phosphor-based LED systems.
Implementation Method 1
A first color light source may include one or more red color light emitting diodes (LEDs). A second color light source may include one or more blue color LEDs. A third color light source may include one or more green color LEDs.
Implementation Method 2
The controller may generate a first color light source drive signal having a first duty cycle. The second color light source drive signal may be generated based on inputs received from the processor unit having a second duty cycle that is greater than the first duty cycle.
Data Source
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AI summary
One embodiment of a system and method for imaging objects from a barcode scanner may include generating a first color light source drive signal having a first duty cycle and a second color light source drive signal having a second duty cycle that is greater than the first duty cycle. In response to applying the first and second color light source drive signals to first and second color light sources, respectively, combining light beams generated by the first and second color light sources to produce a white illumination beam. An image sensor may generate image data of an object inclusive of a chine readable indicia captured in an image by the image sensor while illuminated by the white illumination beam. The machine readable indicia of the object in the image data may be read.