Multi-Layer Optical Sheet Modulation for Backlight Brightness Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing backlight systems for liquid crystal display devices face brightness unevenness due to positional deviations of light scattering bodies, which can be caused by manufacturing errors, assembly errors, or thermal expansion, impairing the brightness equalization function.
Innovation Solution
A lighting device configuration that includes multiple optical sheets with modulation regions, where the first and second optical sheets have superimposed modulation regions with high reflectance over light source regions, and optionally a third optical sheet, to effectively modulate light and suppress brightness unevenness even with positional deviations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a light scattering body with light adjusting dots is disposed between light sources and light valve to equalize brightness, then brightness uniformity is improved, but the system becomes sensitive to positional deviation of the light scattering body
Solution Approach 1:
The light scattering body is divided into multiple light scattering layers, each containing light adjusting dots. By segmenting the single light scattering body into multiple layers with different dot patterns, the system maintains brightness equalization functionality even when individual layers are positioned with deviations, as other layers compensate for the misalignment
Solution Approach 2:
Different light scattering layers are designed with different light adjusting dot patterns tailored to their specific positions and functions. Each layer has locally optimized dot arrangements that address specific brightness不均匀 issues at different depths, making the overall system more robust to positional deviations
2Illumination intensity
If multiple light scattering bodies are stacked to enhance brightness equalization, then brightness uniformity is improved, but the system becomes more vulnerable to positional deviation errors
Solution Approach 1:
The light scattering body is segmented into multiple functional layers with distinct light adjusting dot patterns. Each layer performs a specific function in the brightness equalization process, and the segmentation allows each layer to be optimized independently, reducing the impact of positional deviations
Solution Approach 2:
Light adjusting dots are pre-configured in each layer with patterns that anticipate and compensate for potential positional deviations. The dot patterns are designed in advance to ensure that even if layers shift during assembly or operation, the overall brightness equalization function is maintained
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 configuration effectively suppresses brightness unevenness by ensuring that the modulation action is maintained despite positional deviations of the optical sheets, enhancing light homogenization and reducing the impact of positional errors.
Implementation Method 1
a modulation action of light included in the first optical sheet and the second optical sheet includes at least one of reflection and scattering of light
Implementation Method 2
a modulation action of light included in the first optical sheet and the second optical sheet includes at least one of reflection and scattering of light
Data Source
AI summary
According to an aspect of the disclosure, a lighting device includes: a plurality of light sources; and a plurality of optical sheets disposed to be stacked at a position away from the plurality of light sources. The plurality of optical sheets include a first optical sheet and a second optical sheet. Each of the first optical sheet and the second optical sheet has a unit region that modulates light emitted from a light source for each of the plurality of light sources. The unit region includes a modulation region including a light source region facing the light source, and having a relatively high modulation action of the light as compared with other regions.