Dual-Lens LED Light Module for LCD Backlight Uniformity
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Solution Overview
Problem
Existing flat light units for liquid crystal displays, particularly those using LEDs, face challenges in achieving uniform white light emission due to light loss and imbalance in red, green, and blue light combinations, leading to reduced image brightness and quality, and are hindered by the thickness of diffusion sheets and PMMA plates.
Innovation Solution
The implementation of light modules with a first lens and a second lens, where the second lens features a concave portion, refracts light to maintain a uniform balance and intensity of red, green, and blue lights, eliminating the need for thick PMMA plates and high-haze diffusion sheets, thereby enhancing light distribution and reducing device thickness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a diffusion sheet with high haze and a thick PMMA plate are used to improve light distribution, then the light distribution is improved, but light loss occurs and the device thickness increases
Solution Approach 1:
The patent extracts and eliminates the thick PMMA plate and high-haze diffusion sheet from the optical path. By removing these components that cause light loss, the invention achieves uniform light distribution without the associated energy loss and thickness penalties.
Solution Approach 2:
The patent introduces a reflective sheet as an intermediary component between the LED array and the liquid crystal panel. This reflective sheet redirects diagonally emitted light into the perpendicular direction, achieving uniform light distribution without requiring thick diffusion materials that cause light loss.
2Illumination intensity
If a diffusion sheet with high haze and a thick PMMA plate are used to improve light distribution, then the light distribution is improved, but the device thickness increases
Solution Approach 1:
The patent removes the thick PMMA plate and high-haze diffusion sheet from the device structure. By extracting these thickness-contributing components, the invention achieves uniform light distribution while significantly reducing the overall device thickness.
Solution Approach 2:
The reflective sheet serves as a thin intermediary that redirects light efficiently without adding significant thickness. This allows the device to maintain a slim profile while achieving the desired light distribution uniformity.
3Illumination intensity
If red, green, and blue LEDs are arranged alternately to generate white light, then white light is generated, but it is difficult to maintain a combination balance of the lights
Solution Approach 1:
The reflective sheet acts as an intermediary that receives light from all LED colors and redirects it uniformly. This mediation process helps maintain the combination balance of red, green, and blue lights by ensuring equal optical path lengths and redistribution opportunities for all wavelengths.
Solution Approach 2:
The invention creates equipotential conditions for all LED emissions by using the reflective sheet to provide equal redistribution opportunities for red, green, and blue light. This ensures that no single color dominates or is underrepresented in the final white light output.
4Use of energy by moving object
If LEDs are used instead of CCFLs or EEFLs, then power consumption is reduced and device size is reduced, but uniform white light emission is difficult to achieve
Solution Approach 1:
The reflective sheet serves as a mediator that compensates for the directional emission characteristics of LEDs. By redirecting diagonally emitted light into the perpendicular direction, it ensures uniform white light emission across the display area while maintaining the energy efficiency and compact size advantages of LED technology.
Solution Approach 2:
The invention transforms the light emission pattern from a two-dimensional planar distribution to a three-dimensional redirected path. By utilizing the reflective sheet to bounce light at different angles, the system achieves uniform perpendicular light emission that maintains LED efficiency while improving uniformity.
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 configuration ensures improved image quality with uniform color combination and brightness by minimizing light loss and maintaining a balanced white light emission, allowing for a thinner liquid crystal display device.
Implementation Method 1
a first lens and a second lens, wherein the second lens has a concave portion, refract light
Data Source
AI summary
A liquid crystal display device may include a backlight unit for providing light for the display. A backlight unit may include light modules. The light modules include colored LEDs surrounded by a first lens for refracting the light from the LEDs. A second lens surrounds the first lens for further refraction of the light to improve brightness and the uniformity of the light.