Zigzag LED Arrangement in Light Guide Plate for Uniform Illumination
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Solution Overview
Problem
Surface light-source devices using fluorescent lamps face limitations in thickness reduction and exhibit significant light emission unevenness due to the cos θ emission distribution of LEDs, leading to excessive overhead light emission.
Innovation Solution
A surface light-source device comprising a luminescent panel with aligned light-emitting element lines and a light guide unit featuring a rectangular emission surface, thick and thin portions, an incline rear portion, and a parallel groove, where LEDs are arranged in a zigzag formation within the groove to diffuse overhead light and reduce emission unevenness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a fluorescent lamp is used as the light source, then the light emission is relatively uniform, but the device thickness cannot be reduced due to the diameter of the fluorescent lamp
Solution Approach 1:
The patent changes the light source from fluorescent lamp to LED, and modifies the LED arrangement pattern from linear to zigzag formation. This parameter change allows achieving both thin profile and uniform light emission by optimizing the spatial distribution of light-emitting elements.
Solution Approach 2:
The patent introduces asymmetry in the LED arrangement by using zigzag formation instead of straight linear arrangement. This asymmetric positioning of LEDs compensates for the cosθ emission pattern, distributing light more uniformly across the display surface while maintaining thin device profile.
2Length of stationary object
If an LED is used as the light source, then the device thickness is reduced and power consumption is lowered, but emission unevenness becomes conspicuous due to cos θ emission distribution
Solution Approach 1:
The patent introduces asymmetry in the LED arrangement by using zigzag formation instead of straight linear arrangement. This asymmetric positioning of LEDs compensates for the cosθ emission pattern, distributing light more uniformly across the display surface while maintaining thin device profile.
Solution Approach 2:
The patent applies local quality by varying the spacing and positioning of LEDs in different zones of the zigzag arrangement. LEDs are positioned with different intervals in different sections to locally compensate for the cosθ emission characteristics, achieving uniform overall illumination.
3Device complexity
If LEDs are arranged in a linear formation, then the structure is simple, but the LEDs are not uniformly distributed leading to emission unevenness
Solution Approach 1:
The patent introduces asymmetry in the LED arrangement by using zigzag formation instead of straight linear arrangement. This asymmetric positioning of LEDs compensates for the cosθ emission pattern, distributing light more uniformly across the display surface while maintaining thin device profile.
Solution Approach 2:
The patent transitions from one-dimensional linear LED arrangement to a two-dimensional zigzag pattern. This dimensional change allows better spatial distribution of LEDs, improving light uniformity while maintaining relatively simple structure.
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 achieves reduced thickness, lower electric power consumption, and uniform light emission, improving luminous efficiency and durability while minimizing the need for complex light diffusion processes.
Implementation Method 1
the light emitted to an overhead portion of the LED and having the highest light amount is diffused by a groove surface of the parallel groove
Implementation Method 2
The light guide unit guides the light of the luminescent panel toward the outside
Implementation Method 3
The light guide unit guides the light of the luminescent panel toward the outside
Implementation Method 4
at least one luminescent panel and at least one light guide unit. The luminescent panel includes a plurality of light-emitting element lines formed by aligning light-emitting elements
Implementation Method 5
The light-emitting element is an LED
Data Source
AI summary
A surface light-source device is composed of a light guide plate, luminescent panels and reflector sheets. The light guide plate is composed of three light guide units respectively formed in a rectangular plate-like shape having a rectangular light emission surface, a thick portion, a thin side portion, an incline rear portion and a parallel groove. The luminescent panel includes two element lines formed by aligning LEDs. The parallel groove is formed so as to be symmetrical about a center line, which is perpendicular to the light emission surface, and so as to dwindle its width toward the light emission surface. The light emitted from the LED toward an overhead portion and having the highest brightness is diffused by a groove surface of the parallel groove and is taken into the light guide unit. Thus, brightness unevenness is reduced at the light emission surface.