Grooved Light-Guide Plate for Slim Backlight Module
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Solution Overview
Problem
Conventional direct-type backlight modules for LCD devices are limited in thickness due to the required distance between the reflector and optical films, which restricts the development of slim and lightweight devices while maintaining adequate light mixing to avoid lamp mura.
Innovation Solution
A reduced-thickness direct-type backlight module design featuring a light-guide plate with grooved surfaces and diffuser elements, where light sources are positioned under the grooved surface and optical films are on top, allowing for a minimized light-mixing area height without causing appreciable lamp mura, achieved by optimizing the grooves and diffuser element distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the distance between the reflector and optical films is increased to allow sufficient light mixing, then lamp mura is avoided, but the thickness of the backlight module increases
Solution Approach 1:
The invention introduces a light guide plate with grooves that segments the light mixing process into multiple regions. The grooves create separate light mixing zones that allow sufficient light diffusion distance while maintaining an overall thin module structure. This segmentation enables light from multiple lamps to mix uniformly without requiring a large single continuous space.
Solution Approach 2:
The invention transitions from a conventional planar light mixing approach to a three-dimensional structure using grooves in the light guide plate. The grooves create vertical depth and lateral channels for light mixing, utilizing multiple dimensions to achieve thorough light diffusion within a compact thickness. This dimensional transformation allows sufficient light mixing path length without increasing the overall module thickness.
2Reliability
If the number of lamps is increased to improve light mixing, then lamp mura is reduced, but the device becomes heavier and more complex
Solution Approach 1:
The invention introduces a light guide plate with integrated grooves as an intermediary structure between the lamps and optical films. This mediator performs the light mixing function that would otherwise require multiple lamps, by guiding and diffusing light through its grooved structure. The light guide plate consolidates the light mixing function into a single component rather than requiring multiple light sources.
Solution Approach 2:
The invention changes the structural parameters of the light guide plate by introducing grooves with specific dimensions and patterns. These parameter changes enable the light guide plate to perform light mixing functions, transforming it from a simple flat plate into an active optical component that can replace multiple lamps while maintaining uniform light distribution.
3Length of stationary object
If the thickness of the backlight module is reduced, then slim LCD devices are achieved, but light mixing becomes insufficient causing lamp mura
Solution Approach 1:
The grooves in the light guide plate segment the limited thickness space into multiple functional zones for light mixing. By dividing the light mixing process into discrete segments within the grooves, the invention achieves thorough light diffusion without requiring a large overall thickness. Each groove acts as a mini light mixing chamber.
Solution Approach 2:
The invention compensates for reduced thickness by utilizing the vertical dimension created by the grooves. The grooves provide depth and lateral pathways for light mixing within the constrained thickness, transforming a two-dimensional planar mixing problem into a three-dimensional solution that fits within thin form factors.
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 enables a thinner and lighter-weight backlight module that maintains uniform light distribution and avoids lamp mura, enhancing the brightness and reducing the overall thickness below 20 mm, facilitating the creation of slimmer LCD devices.
Implementation Method 1
a light-guide plate, having a grooved first surface and a second surface opposite the first surface
Implementation Method 2
diffuses the light produced by the lamps 11 onto a liquid crystal panel in a homogeneous manner
Implementation Method 3
The reflector 13 is disposed within the housing 14 and reflects light diffused from the lamps 11 to the inner side of the housing 14 and to the diffusion plate 12
Data Source
AI summary
A direct-type backlight module includes a light-guide plate. The light-guide plate has a first surface and a second surface opposite the first surface. The first surface has at least one first groove. The backlight module may also include at least one light source. The light source corresponds to the first groove so that light emitted from the light source is reflected by the first groove. One or more optical films may be disposed on the first surface of the light-guide plate and a reflector may be disposed below the second surface of the light-guide plate. With the light-guide plate in place, the overall thickness of the backlight module is reduced, and the lamp mura is avoided.