LED Light Module Layout for Dark Spot-Free Edge Backlights
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Solution Overview
Problem
Existing light emitting devices used in edge type backlight modules suffer from dark spots due to insufficient light distribution between adjacent devices, and they struggle to maintain high luminous efficacy while keeping a small size.
Innovation Solution
A light emitting device comprising a light emitting diode chip, a light transmitting member, a white barrier member, and an electrically conductive bonding member, where the white barrier member exposes opposite short side surfaces of the light transmitting member, allowing for improved light distribution and reduced separation distance between adjacent devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the separation distance between adjacent light emitting devices is increased, then light distribution is improved and dark spots are prevented, but the overall device size and module complexity increase
Solution Approach 1:
A light reflecting member is introduced as an intermediary component between adjacent light emitting devices. This member reflects light that would otherwise be lost in the separation region back toward the light guide plate, improving light distribution and preventing dark spots without requiring increased separation distance between devices.
Solution Approach 2:
The refractive index of the light transmitting member is specifically controlled to be higher than that of the light reflecting member. This parameter change optimizes light reflection and extraction efficiency, allowing compact device spacing while maintaining good light distribution through the light guide plate.
2Productivity
If the size of light emitting devices is reduced for compact module design, then manufacturing convenience is improved, but light distribution between adjacent devices deteriorates causing dark spots
Solution Approach 1:
The light reflecting member acts as a mediator that compensates for the reduced light output from compact devices. By reflecting stray light back into the light guide plate, it ensures sufficient illumination even when devices are closely spaced for compact module design.
Solution Approach 2:
The light reflecting member is positioned specifically in the separation region between adjacent devices, providing localized light reflection where it is most needed. This targeted approach improves light distribution in critical areas without affecting the compact overall design.
3Loss of energy
If the refractive index of the light transmitting member is increased to improve light extraction, then luminous efficacy is improved, but manufacturing precision requirements increase
Solution Approach 1:
The refractive index of the light transmitting member is optimized to be higher than the light reflecting member, creating favorable optical conditions for light extraction. This parameter change improves luminous efficacy by enhancing total internal reflection and light extraction efficiency at the interfaces.
Solution Approach 2:
The light reflecting member with lower refractive index serves as an intermediary that facilitates light extraction from the high refractive index light transmitting member. This refractive index difference creates optimal conditions for light extraction without requiring extremely tight manufacturing tolerances.
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 enhances luminous efficacy while maintaining a compact size, effectively preventing dark spots by ensuring sufficient light reaches the regions between adjacent light emitting devices.
Implementation Method 1
a light emitting diode chip
Implementation Method 2
a white barrier member covers opposite long side surfaces of the light transmitting member
Data Source
AI summary
A light emitting device includes a light emitting diode chip, a light transmitting member, a white barrier member, and a conductive adhesive member. The light emitting diode chip has a bump pad formed on the lower surface thereof. The light transmitting member covers the side surfaces and the upper surface of the light emitting diode chip, and the upper surface of the light transmitting member has a rectangular shape having long sides and short sides. The conductive adhesive member is formed to extend through the white barrier member from the bottom of the light emitting diode chip. The upper surface of the conductive adhesive member is connected to the bump pad of the light emitting diode chip, and the lower surface of the conductive adhesive member is exposed at the lower surface of the white barrier member.