Light Guide Plate Screen Dots for Backlight Color Stability
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Solution Overview
Problem
Existing LCD backlight modules experience rapid luminous efficiency degradation and color shift due to the heat-sensitive nature of fluorescent powder coatings on LED chips, leading to poor long-term performance and efficiency.
Innovation Solution
A light guide plate with screen dots comprising fluorescent powder and diffusion particles, where the fluorescent powder is not coated inside the LEDs, allowing for separation from the heat source and improved light diffusion, generating white light through a Red+Green+Blue combination, and arranged in various configurations to ensure uniform color and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If fluorescent powder is coated on LED chip, then white light is generated, but luminous efficiency degrades rapidly due to heat accumulation
Solution Approach 1:
The patent extracts the fluorescent powder from the LED chip interior and relocates it to the light guide plate. This separation removes the heat-sensitive fluorescent powder from direct contact with the heat-generating LED chip, allowing the LED to maintain high luminous efficiency without the degradation caused by thermal accumulation in the fluorescent coating.
Solution Approach 2:
The light guide plate serves as an intermediary component between the LED chip and the fluorescent powder. Light from the LED chip travels through the light guide plate to reach the fluorescent powder, which then converts the light to white light. This intermediary structure protects the fluorescent powder from direct heat exposure while maintaining its light conversion function.
2Illumination intensity
If fluorescent powder is coated on LED chip, then white light is generated, but color shift occurs due to accelerated ageing
Solution Approach 1:
By extracting the fluorescent powder from the LED chip interior and placing it in the light guide plate, the patent eliminates the direct thermal aging pathway. The fluorescent powder is no longer subjected to the high temperatures generated by the LED chip, preventing accelerated aging and color shift over the service life of the backlight module.
Solution Approach 2:
The patent converts the harmful thermal environment into a beneficial separation strategy. By allowing the LED chip to generate heat freely without fluorescent powder present, and placing the fluorescent powder in a cooler location (light guide plate), the harmful thermal effect is transformed into a protective spatial separation that extends component life and maintains color consistency.
3Power
If fluorescent powder is coated on LED chip, then light is generated, but heat accumulation causes resistance to high temperature
Solution Approach 1:
The patent extracts the fluorescent powder from the heat-prone LED chip interior and relocates it to the light guide plate. This allows the LED chip to operate at high power levels without the constraint of thermal resistance in the fluorescent coating, while the fluorescent powder in the cooler light guide plate environment maintains its light conversion capability.
Solution Approach 2:
The patent segments the light generation system into two distinct functional zones: the LED chip zone for efficient light generation without thermal constraints, and the light guide plate zone for fluorescent conversion in a thermally favorable environment. This segmentation allows each component to operate in its optimal thermal regime.
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
Prevents color shift and luminous efficiency degradation by isolating fluorescent powder from heat sources, ensuring consistent light output and improved light guide efficiency through effective diffusion and mixing of light.
Implementation Method 1
The screen dots comprise fluorescent powder... generating white light through a Red+Green+Blue combination
Implementation Method 2
part of light is diffused by the diffusion particles on the screen dots 130 and emitted through the light-emitted surface
Implementation Method 3
The light propagates in the light guide plate 120 by total reflection
Data Source
AI summary
The present invention provides a light guide plate and a backlight module, wherein the light guide plate comprises a bottom surface, a light incident surface and a light-emitting surface. The light-emitting surface and the bottom surface are positioned oppositely. The bottom surface comprises a plurality of screen dots. The screen dots comprise fluorescent powder and are selectively added with diffusion particles. The present invention prevents the phenomenon of color shift and the luminous efficiency degradation due to the fluorescent powder accelerated ageing because of closing to the LED chip.