Thin Front Light Guide Module for Uniform Reflective Display Lighting
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Solution Overview
Problem
Conventional reflective displays integrated with touch panels face challenges in achieving a thin design while maintaining structural stability and optical performance, such as insufficient brightness, hot spots, and structural defects due to thinning of the light guide plate.
Innovation Solution
A front light guide module with a light guide plate thickness of 0.1 mm to 0.3 mm, incorporating optical microstructures, a flexible circuit board with mini light-emitting diodes, and a composite light path adjustment layer comprising a reflective and light-shielding layer, ensuring efficient light distribution and structural stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the light guide plate thickness is reduced to achieve thin design, then the device thickness is reduced, but structural stability and optical performance deteriorate
Solution Approach 1:
The patent uses a composite structure combining the light guide plate with the light source module and composite light path adjustment layer. The light source module includes a flexible circuit board with mini light-emitting diodes that are coplanar with the light guide plate, creating a integrated composite structure that maintains structural stability while achieving thin design.
Solution Approach 2:
The patent divides the light guide system into separate functional modules: the light guide plate, the light source module with flexible circuit board, and the composite light path adjustment layer. This segmentation allows each component to be optimized independently while maintaining overall structural integrity and optical performance.
2Length of moving object
If the light guide plate thickness is reduced to achieve thin design, then the device thickness is reduced, but optical performance (brightness and uniformity) deteriorates
Solution Approach 1:
The patent introduces optical microstructures on the surface of the light guide plate to control light distribution locally. The composite light path adjustment layer with reflective and light-shielding layers is positioned at specific locations to adjust light paths and eliminate hot spots, achieving uniform brightness distribution across the display.
Solution Approach 2:
The patent optimizes the vertical distance between light-emitting diodes and the light guide plate side-lit surface to 0.01mm-0.6mm, and controls the LED height to be ≤ the light guide plate thickness. These parameter optimizations ensure efficient light coupling while maintaining thin design and uniform optical performance.
3Length of moving object
If the light guide plate is thinned to meet thin design requirements, then device thickness is reduced, but manufacturing complexity increases due to precision requirements
Solution Approach 1:
The patent merges the light source module with the light guide plate by making the flexible circuit board carry a portion of the light guide plate and positioning light-emitting diodes coplanar with it. This integration reduces the number of separate components and simplifies assembly, lowering manufacturing precision requirements while maintaining thin design.
Solution Approach 2:
The composite light path adjustment layer acts as an intermediary between the light source module and the light guide plate, facilitating proper light coupling and alignment. This intermediate layer simplifies the assembly process by accommodating minor position variations and reducing the need for high-precision alignment.
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 maintains high brightness (≥120 cd/m2) and uniformity (≥80%) while preventing structural discontinuities, enhancing light mixing, and simplifying manufacturing processes, thus achieving a slim design without compromising optical performance.
Implementation Method 1
a light guide plate... with a side-lit surface interconnecting the top surface and the bottom surface... The light-emitting diodes face the side-lit surface
Implementation Method 2
The reflective layer covers the light-emitting diodes and a portion of the top surface of the light guide plate
Implementation Method 3
The light-shielding layer is stacked on the reflective layer and relatively away from the light-emitting diodes and the light guide plate compared to the reflective layer
Implementation Method 4
at least one of the top surface or the bottom surface is equipped with a plurality of optical microstructures
Data Source
AI summary
A front light guide module disposed on a reflective display includes a light guide plate, a light source module, and a composite light path adjustment layer. The light source module includes a flexible circuit board and a plurality of light-emitting diodes. The light-emitting diodes are disposed on an opaque reflective surface of the flexible circuit board. A vertical distance from a top surface of each of the light-emitting diodes to the flexible circuit board is smaller than or equal to a vertical distance from a top surface of the light guide plate to the flexible circuit board. The composite light path adjustment layer includes a reflective layer and a light-shielding layer. An average brightness of the front light guide module on the reflective display is larger than 120 cd/m2, with a brightness uniformity that is larger than 80%.