LED Lighting Device with Stacked Light Guides and Prism Arrays
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Solution Overview
Problem
Conventional lighting devices with small light distribution angles require a certain depth, making them bulky, and high-temperature LEDs necessitate power-consuming heat sinks, which increases energy consumption and device thickness.
Innovation Solution
A lighting device design featuring a first and second light guide with prism arrays and liquid crystal lenses, where LEDs are disposed along the light guides' sides, and heat is dissipated through a metal frame, reducing power consumption and eliminating the need for heat sinks, while maintaining a small light distribution angle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a parabolic mirror is used to form parallel light for small light distribution angle, then the light distribution angle is reduced, but the device depth increases making it bulky
Solution Approach 1:
The patent replaces the mechanical parabolic mirror system with an optical system consisting of light guides and lens arrays. The light guides transmit light from LED arrays, and the lens arrays (including convex lenses and cylindrical lenses) collimate the light to achieve small distribution angles without requiring the deep structure of a parabolic mirror
Solution Approach 2:
The patent uses multiple light guides arranged in different spatial dimensions and orientations to achieve light collimation from multiple directions. This multi-dimensional approach allows the system to achieve parallel light output without the single deep cavity required by traditional parabolic mirrors
2Illumination intensity
If high power LEDs are used to increase luminous output, then the illumination intensity is improved, but heat generation increases requiring power-consuming heat sinks
Solution Approach 1:
The patent converts the harmful heat generated by LEDs into a beneficial feature by designing the light guide system to work efficiently with the thermal characteristics of high-power LEDs. The close coupling of LEDs to light guides allows direct conversion of electrical energy to light with minimal thermal loss, and the system is optimized to maintain LED efficiency even at elevated temperatures
Solution Approach 2:
The patent merges the LED light source directly with the light guide input, eliminating the need for separate heat management components. The LED arrays are mounted directly on the light guides, allowing efficient heat transfer and eliminating the need for additional heat sinks that would increase power consumption
3Illumination intensity
If high power LEDs are used to increase luminous output, then the illumination intensity is improved, but the light emitting efficiency decreases due to high temperature
Solution Approach 1:
The patent optimizes multiple parameters including the refractive indices of light guide materials, the focal lengths and arrangements of lens arrays, and the spacing between LEDs and light guides. These parameter optimizations ensure that the system maintains high light extraction efficiency and minimal optical losses even when operating with high-power LEDs at elevated temperatures
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 design achieves a thin, low-power consumption lighting device with a small light distribution angle, reducing heat generation and allowing for efficient light collimation without the need for heat sinks, resulting in a more compact and energy-efficient solution.
Implementation Method 1
a light guide, having a light incident surface on which the light from the LED is incident and a light emitting surface opposite to the light incident surface
Implementation Method 2
a reflecting sheet disposed under the back surface of the light guide
Implementation Method 3
a lens array; in which the light guide has a fan like first region, which opposes to the plurality of the first LEDs, and a fan like second region, which does not oppose to the plurality of the first LEDs
Data Source
AI summary
The purpose of the present invention is to realize a lighting device of thin, low power consumption and high emitting efficiency. A concrete structure of the inventions is as follows. A lighting device including a first light guide and a second light guide stacked on the first light guide, a reflecting sheet disposed under the first light guide, and a prism sheet disposed on the first light guide, in which a concentric first prism array is formed on the prism sheet, a plurality of first LEDs are disposed along a circumferential direction of a side wall of a first hole of the first light guide, a plurality of second LEDs are disposed along a circumferential direction of a side wall of a second hole of the second light guide, and the plurality of the first LEDs and the plurality of the second LEDs are displaced in azimuth direction.