Backlight Reflection Partition for Display Color Uniformity
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Solution Overview
Problem
Backlight devices using blue LEDs and wavelength conversion sheets often result in coloration issues at the screen end portion due to uneven light distribution, causing a bluer tint compared to the screen center, leading to inaccurate color representation.
Innovation Solution
A backlight device configuration that includes a light source unit with blue LEDs, a wavelength conversion sheet, and a reflection partition surrounding the light source unit to prevent light leakage and ensure uniform chromaticity across the screen.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a blue LED and wavelength conversion sheet are used to obtain white light, then power consumption is reduced and luminance control is improved, but color uniformity deteriorates at screen end portions
Solution Approach 1:
The backlight device is divided into multiple independent light source units, each corresponding to a specific screen region. Each light source unit includes blue LEDs and a wavelength conversion sheet, allowing independent control of each segment. This segmentation enables local dimming and color uniformity compensation without affecting the entire backlight system.
Solution Approach 2:
Different screen regions are provided with different numbers of blue LEDs or different luminance characteristics based on their specific requirements. Screen end portions, which tend to appear darker, are compensated with additional LEDs or adjusted luminance settings to achieve uniform overall appearance while maintaining the energy efficiency of the blue LED wavelength conversion system.
2Ease of operation
If blue LEDs are used with wavelength conversion sheet, then luminance control becomes easier, but chromaticity uniformity deteriorates across the screen
Solution Approach 1:
The backlight device is divided into multiple independent light source units, each corresponding to a specific screen region. Each light source unit includes blue LEDs and a wavelength conversion sheet, allowing independent control of each segment. This segmentation enables local dimming and color uniformity compensation without affecting the entire backlight system.
Solution Approach 2:
The backlight device incorporates dynamic control capabilities where the luminance of each light source unit can be independently adjusted in real-time. This dynamic control allows the system to compensate for chromaticity variations across different screen regions, maintaining uniform color appearance while preserving the ease of luminance control inherent to LED systems.
3Device complexity
If phosphor sheet is used to convert blue light to white light, then simple structure is achieved, but coloration occurs at screen end portion
Solution Approach 1:
The backlight device is divided into multiple independent light source units, each corresponding to a specific screen region. Each light source unit includes blue LEDs and a wavelength conversion sheet, allowing independent control of each segment. This segmentation enables local dimming and color uniformity compensation without affecting the entire backlight system.
Solution Approach 2:
Different screen regions are provided with different numbers of blue LEDs or different luminance characteristics based on their specific requirements. Screen end portions, which tend to appear darker, are compensated with additional LEDs or adjusted luminance settings to achieve uniform overall appearance while maintaining the structural simplicity of the phosphor sheet conversion system.
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 reflection partition suppresses light emission from blue LEDs to surrounding regions, achieving uniform chromaticity and preventing coloration at the screen end portion, while maintaining low power consumption and expanding the dynamic range through local dimming control.
Implementation Method 1
a wavelength conversion sheet that converts a wavelength of light emitted from the blue light emitting element so that a color of light emitted to an outside becomes white
Implementation Method 2
a reflection partition that is provided so as to surround the light source unit
Data Source
AI summary
Occurrence of coloration at a screen end portion is suppressed when a backlight device having a configuration combining a blue LED and a wavelength conversion sheet is adopted.In a backlight device (600) adopting a configuration combining a blue LED (63) and a phosphor sheet (65) in order to obtain white light, a reflection partition (67) is provided on an LED substrate (62) so as to surround the blue LED (63) (more specifically, so as to surround an LED unit including one or a plurality of blue LEDs (63)). A surface of the reflection partition (67) is formed of a reflection material. A height and an angle of the reflection partition (67) is designed so that light emitted from the blue LED (63) corresponding to each area does not reach other areas.