Side-Emission Backlight Structure for Thin Uniform Displays
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Solution Overview
Problem
There is a need to further reduce the thickness of display apparatuses without degrading the in-plane uniformity of illumination light, as existing technologies face challenges in achieving this goal while maintaining light quality.
Innovation Solution
A light-emitting unit with side-emission type light-emitting devices, a light guide plate with uneven layers on its surfaces, and a reflective structure fixed to both the mounting and bottom surfaces, which reflects output light towards the bottom surface of the light guide plate, ensuring in-plane uniformity and allowing for a thinner design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If top-emission type light-emitting devices are used, then the structure is simpler, but the clearance between light-emitting devices and light guide plate must be larger to ensure in-plane uniformity
Solution Approach 1:
The patent inverts the light emission direction from top-emission to side-emission type light-emitting devices. This inversion allows the light to enter the light guide plate from the side through a reflective structure, eliminating the need for a large clearance between the light-emitting devices and the light guide plate while maintaining in-plane uniformity of illumination light.
Solution Approach 2:
The patent changes the light emission dimension from vertical (top-emission) to horizontal (side-emission). By disposing the light-emitting devices edge-up and using a reflective structure to direct light horizontally into the light guide plate, the design achieves thinner overall structure while maintaining illumination uniformity without requiring large vertical clearance.
2Length of stationary object
If the thickness is reduced, then the display apparatus becomes thinner, but the in-plane uniformity of illumination light deteriorates
Solution Approach 1:
By inverting to side-emission type light-emitting devices and using a reflective structure to direct light horizontally into the light guide plate, the patent achieves thinner overall structure while maintaining illumination uniformity. The side-emission configuration allows for reduced thickness without compromising in-plane uniformity of the illumination light.
Solution Approach 2:
The patent applies uneven layers with different refractive indices at specific locations within the light guide plate to locally control light propagation. This local quality adjustment ensures in-plane uniformity of illumination light even in a thin structure, as the uneven layers are strategically positioned to correct uniformity issues without increasing overall thickness.
3Length of stationary object
If side-emission type light-emitting devices are used with reflective structure, then the clearance is reduced and thickness is minimized, but the structure becomes more complex
Solution Approach 1:
The patent merges the reflective structure with the mounting surface or bottom surface of the light guide plate, integrating multiple functions into a single component. This merging reduces the overall clearance and thickness while managing structural complexity through functional integration rather than adding separate components.
Solution Approach 2:
The mounting surface or bottom surface of the light guide plate serves multiple functions: it provides mechanical support, acts as a reflective surface to direct light horizontally, and integrates the reflective structure. This multi-functionality reduces the need for separate components, thereby minimizing clearance and thickness while controlling overall structural complexity.
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 the clearance between light-emitting devices and the light guide plate, ensuring in-plane uniformity of illumination light while enabling a further reduction in thickness without compromising light quality.
Implementation Method 1
reflective structure has a reflective section reflecting output light from each of the light-emitting devices toward the bottom surface
Implementation Method 2
uneven layers on a bottom surface and a top surface, the uneven layers controlling entry and exit of light
Data Source
Figure 1
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AI summary
A light-emitting unit according to an embodiment of the present disclosure includes: a plurality of side-emission type light-emitting devices disposed two-dimensionally on a mounting surface; a light guide plate that is disposed at a position opposed to each of the light-emitting devices, and has uneven layers on a bottom surface and a top surface, the uneven layers controlling entry and exit of light; and a reflective structure that is fixed to at least the bottom surface out of the mounting surface and the bottom surface, and has a reflective section, the reflective section reflecting output light from each of the light-emitting devices toward the bottom surface.