Perpendicular LED Light Emission Orientation for Backlighting
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Solution Overview
Problem
Conventional LED devices have inefficient sideways light emission, leading to bulky and complex optical designs in applications like liquid crystal display backlighting systems, where it is desirable to have a more uniform and directed light emission pattern.
Innovation Solution
The LED device is designed with its light emitting region occupying a plane perpendicular to the mounting surface, utilizing a multi-layer semiconductor substrate with p-type and n-type semiconductor layers, and a light transmissive layer to enhance sideways light emission, with optional reflective or opaque masks to redirect light emissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If conventional LED devices are used with light emitting region parallel to mounting surface, then light emission is efficient in perpendicular direction, but sideways light emission is poor requiring bulky optical designs
Solution Approach 1:
The patent rotates the light emitting region from a parallel orientation to a perpendicular orientation relative to the mounting surface. This dimensional change transforms the light emission pattern, enabling efficient sideways light emission without requiring additional optical components, thereby resolving the contradiction between illumination intensity and device complexity.
2Loss of energy
If reflective surfaces or dishes are added to recover light, then light emission efficiency improves, but device complexity and packaging size increase
Solution Approach 1:
Instead of adding reflective surfaces or dishes to redirect light, the patent changes the orientation of the light emitting region to perpendicular mounting. This dimensional change inherently redirects light emission in the desired direction, achieving the same energy recovery effect without adding complex optical components or increasing packaging size.
3Ease of manufacture
If conventional LED mounting is used, then fabrication is simple, but light emission pattern is not suitable for backlight illumination systems
Solution Approach 1:
The patent maintains fabrication simplicity while changing the mounting orientation to perpendicular. This dimensional change makes the LED suitable for backlight illumination systems where sideways light emission is required, thereby improving adaptability without sacrificing ease of manufacture.
4Stability of the object's composition
If more LEDs are used to achieve uniform light distribution, then illumination uniformity improves, but device complexity and packaging size increase
Solution Approach 1:
By changing the mounting orientation to perpendicular, each LED inherently provides a wider and more uniform light distribution pattern. This dimensional change reduces the number of LEDs required to achieve the desired uniformity, thereby improving light distribution without increasing device 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 design allows for a more uniform and directed light emission pattern, reducing the complexity and bulkiness of LED packaging and enabling thinner backlight panels with fewer LEDs required for the same lighting effect, while allowing for independently controllable lit regions in LCD panel backlighting.
Implementation Method 1
When a voltage is applied to the LED terminals electrons and holes flow into the p-n junction and when an electron meets a hole it falls into a lower energy level which releases a photon, the fundamental element of light.
Implementation Method 2
Several techniques are available to recover this non-productive light emitted towards the supporting member 109 including adding a reflective surface to the supporting member 109
Data Source
AI summary
A light emitting diode device which, in use, has its light emitting region occupying a plane substantially perpendicular to a plane occupied by the surface on which the device is mounted. The primary light emission directions of the light emitting region are parallel to the surface on which the device is mounted. The device may have both its p-type and n-type semiconductor layers passivated by a layer or layers of light transmissive materials. There is a method for fabricating and mounting such a device. A plurality of the light emitting diode devices can be used in a lighting assembly for providing a plurality of independently controllable lit regions.