Handheld ID Reader With Multi-Mode Illumination for DPM Decoding
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Solution Overview
Problem
Existing ID readers face challenges in efficiently decoding small-scale ID codes, such as DPM codes, due to issues with illumination patterns causing shadow effects and the need for integrating multiple illumination types in a compact, user-friendly handheld device.
Innovation Solution
An ID reader integrating direct, low-angle, and polarized illumination types with a variable focus system and a sealed module assembly, featuring a dichroic filter and a mirror assembly, to optimize focus and illumination for different code types.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If direct (diffuse) illumination is used, then the ID code area is illuminated, but shadow effects occur in the center region
Solution Approach 1:
The illumination system is segmented into multiple independent illumination sources with different characteristics (direct/diffuse illumination and low-angle illumination) that can be activated separately or in combination, allowing each source to address specific illumination needs without causing shadow effects
Solution Approach 2:
Different regions of the illumination system provide different illumination qualities - direct illumination sources provide broad area coverage while low-angle illumination sources provide edge enhancement, with each type optimized for specific regions of the ID code to eliminate shadow effects in the center
2Reliability
If multiple types of illumination are integrated, then decoding performance for small ID codes improves, but device complexity increases
Solution Approach 1:
Multiple illumination types (direct/diffuse and low-angle) are merged into a single integrated illumination assembly that can be controlled as a unified system, reducing the complexity that would result from separate independent systems while maintaining the decoding performance benefits of multiple illumination modes
Solution Approach 2:
The illumination assembly is designed as a universal multi-functional unit that can provide different illumination modes (direct, diffuse, low-angle) depending on the ID code type and reading conditions, eliminating the need for multiple separate illumination systems
3Adaptability or versatility
If variable focus system is added, then focus adjustment for different distances is enabled, but device complexity increases
Solution Approach 1:
The focus system is made dynamic through a variable focus lens that can adjust its focal length in response to different object distances, allowing the system to adapt to handheld operation conditions where the distance between the reader and ID code varies, while the control mechanism remains integrated into the existing system architecture
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 solution provides robust performance in harsh environments, effectively decoding small-scale ID codes by reducing shadow effects and adjusting focus for optimal illumination, enhancing readability and durability.
Implementation Method 1
a variable focus system with liquid lens have been integrated in this module
Implementation Method 2
a dichroic filter and a mirror assembly, to optimize focus and illumination for different code types
Implementation Method 3
is placed on axis using a mirror assembly that includes a dichroic filter
Implementation Method 4
polarized illumination assembly
Implementation Method 5
low-angle illumination assembly
Implementation Method 6
diffuse illumination assembly
Data Source
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AI summary
This provides an ID reader, typically configured for handheld operation, which integrates three types of illumination into a compact package that generates robust performance and resistance to harsh environmental conditions, such as dust and moisture. These illumination types include, direct (diffuse) light, low-angle light and polarized light. The ID reader includes a sealed reader module assembly having the illuminators in combination with an imager assembly (optics and image sensor) at its relative center. Additionally, also an on-axis aimer and a variable focus system with liquid lens have been integrated in this module and is placed on axis using a mirror assembly that includes a dichroic filter. As the optimal distance to read a code with low-angle light is typically shorter than the optimal distance to use the polarized illumination a variable (e.g. liquid) lens can adjust the focus of the reader to the optimal distance for the selected illumination.