Backlight Unit Diffraction Grating Height Variation
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Solution Overview
Problem
In conventional backlight units for 3D image displays, the uniformity of diffracted exit light is compromised due to diffraction gratings having the same height, leading to varying intensity and reduced brightness across different positions.
Innovation Solution
The diffraction gratings in the backlight unit are designed with varying heights, allowing for adjusted diffraction efficiency based on location, ensuring uniform intensity of diffracted exit light by increasing or decreasing grating height and width accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If diffraction gratings have the same height, then the manufacturing process is simple, but the uniformity of diffracted exit light intensity deteriorates
Solution Approach 1:
The patent applies local quality by making the diffraction gratings have different heights at different locations on the light guiding plate. Specifically, the gratings closer to the light source have smaller heights while those farther away have larger heights, optimizing diffraction efficiency at each location to achieve uniform light intensity distribution across the display area.
Solution Approach 2:
The patent changes the height parameter of the diffraction gratings based on their position. By varying the grating height parameter according to location (smaller near light source, larger farther away), the system optimizes diffraction efficiency to compensate for light intensity variations and achieve uniform output across the display area.
2Manufacturing precision
If diffraction gratings have varying heights, then the uniformity of diffracted exit light is improved, but the manufacturing complexity increases
Solution Approach 1:
The patent applies local quality by making the diffraction gratings have different heights at different locations on the light guiding plate. Specifically, the gratings closer to the light source have smaller heights while those farther away have larger heights, optimizing diffraction efficiency at each location to achieve uniform light intensity distribution across the display area.
Solution Approach 2:
The patent changes the height parameter of the diffraction gratings based on their position. By varying the grating height parameter according to location (smaller near light source, larger farther away), the system optimizes diffraction efficiency to compensate for light intensity variations and achieve uniform output across the display area.
3Device complexity
If diffraction gratings have the same height, then the device structure is simple, but the brightness uniformity across display positions deteriorates
Solution Approach 1:
The patent applies local quality by making the diffraction gratings have different heights at different locations on the light guiding plate. Specifically, the gratings closer to the light source have smaller heights while those farther away have larger heights, optimizing diffraction efficiency at each location to achieve uniform light intensity distribution across the display area.
Solution Approach 2:
The patent changes the height parameter of the diffraction gratings based on their position. By varying the grating height parameter according to location (smaller near light source, larger farther away), the system optimizes diffraction efficiency to compensate for light intensity variations and achieve uniform output across the display area.
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 approach enhances the uniformity and brightness of the diffracted exit light, providing a more consistent 3D image display by optimizing diffraction efficiency across the light guiding plate.
Implementation Method 1
directional light is formed through a diffraction grating structure formed on a light guiding plate (LGP) of a backlight unit
Data Source
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AI summary
A backlight unit for a three-dimensional (3D) image display includes a light guiding plate (20) configured to guide light; a light source (10) configured to emit the light to the light guiding plate (20); and a diffraction grating structure (30) provided on a surface of the light guiding plate (20), the diffraction grating structure (30) being configured to diffract the light emitted from the surface of the light guiding plate (20), and including diffracting gratings having different heights.