Smartcard Light-Guiding Module for Uniform Graphic Illumination
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Solution Overview
Problem
Existing smart card illumination technologies result in non-uniform light distribution and blurring of graphic elements due to light scattering through plastic card layers.
Innovation Solution
An illumination module utilizing a light guiding material with protrusions and a reflective layer to refract light perpendicularly and uniformly distribute brightness, combined with energy harvesting and rectifying systems to power LEDs without additional batteries.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If light sources are placed in smart card layers, then illumination function is achieved, but light scattering causes non-uniform brightness and blurred graphics
Solution Approach 1:
A light guiding layer is introduced as an intermediary between the light source and the graphic elements. This layer guides the light from the LED through its internal structure (with higher refractive index) to the extraction layer, controlling light propagation and reducing scattering. The intermediary layer ensures uniform light distribution while maintaining sharp graphic element boundaries.
2Use of energy by moving object
If fluorescent dyes are embedded in plastic material, then light emission is achieved, but fluorescence conversion causes energy loss and delayed response
Solution Approach 1:
The fluorescent dyes are extracted from the plastic material and removed from the system. Instead of using fluorescent conversion, the patent employs a light guiding layer that directly transmits and guides visible light from the LED. This eliminates the energy loss associated with fluorescence conversion and removes the dwell time delay, achieving immediate illumination response.
3Area of stationary object
If light is transmitted through multiple card layers, then illumination coverage is achieved, but light scattering reduces brightness uniformity
Solution Approach 1:
The light guiding layer is designed with spatially varying properties to control light extraction locally. The extraction layer contains graphic elements at specific positions where light should be emitted, while other regions guide light to different areas. This local differentiation ensures uniform brightness distribution across the illumination coverage area while maintaining clear graphic element definition.
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
Ensures uniform brightness distribution and clear illumination of graphic elements on smart cards, reducing energy loss and production costs while maintaining a neat image.
Implementation Method 1
The light guiding material transports light from one location to another by exploiting the principles of total internal reflection at the boundary between the two materials
Implementation Method 2
the light guiding material has a refractive index higher than the refractive index of the surrounding layers... the rays of the emitted light, depending on their incident angle, are not totally internally reflected within the light guiding material
Data Source
Figure 1~2A
Figure 2B
Figure 3A~3B
AI summary
The present invention refers to an illumination module for illuminating a portion of a smart card. The illumination module comprises a substrate layer, one or more lighting elements placed on the substrate layer and configured to emit light parallel to the substrate layer, for instance one or more LEDs, and a light guiding body applied to the substrate layer. The light guiding body comprises a light guiding material and a pattern layer applied to the light guiding material and is configured to refract the light parallel to the substrate layer and deviate it along a direction perpendicular to the substrate layer, so as to obtain an emitted light; the pattern layer comprises a series of protrusions distributed so as to make the brightness of the emitted light uniform.