LCD Color Filter Spectral Optimization for Brightness
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Solution Overview
Problem
Conventional LCD modules face challenges in achieving high brightness due to the overlap of transmission spectra of color filters with emission spectra of LEDs, leading to reduced light filtering effectiveness and increased manufacturing costs when using high purity color filtering layers.
Innovation Solution
The LCD module incorporates a color filter with filtering layers adjusted to reduce overlap between transmission spectra and emission spectra of different color light sources, maintaining a desired NTSC ratio by optimizing the peak values and full width at half maximum of the transmission spectra of each filtering layer, thereby increasing light penetrability and brightness while reducing manufacturing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If high purity color filtering layers are used to improve light filtering effect, then color purity and NTSC ratio are improved, but manufacturing cost increases and light penetrability decreases
Solution Approach 1:
The patent adjusts the transmission spectrum parameters of the color filtering layers, specifically optimizing the peak wavelengths and full width at half maximum (FWHM) values to achieve non-overlapping transmission spectra with LED emission spectra. This parameter optimization allows the use of lower purity filtering materials while maintaining effective color separation, thereby reducing manufacturing costs without sacrificing display quality
Solution Approach 2:
The patent applies partial action by selectively filtering only the specific wavelength ranges that cause overlap between different color channels. Instead of using high purity filters that block all unwanted wavelengths, the invention uses lower purity filters with optimized spectral characteristics that block only the problematic overlapping portions, allowing more light to pass through while maintaining color accuracy
2Manufacturing precision
If high purity color filtering layers are used to improve light filtering effect, then color purity is improved, but light penetrability and brightness decrease
Solution Approach 1:
The patent modifies the transmission spectrum parameters of the filtering layers to achieve non-overlapping spectral characteristics with LED emission. By optimizing peak wavelengths and FWHM values, the filters allow maximum light transmission in the desired wavelength ranges while blocking only the specific overlapping portions, thereby maintaining high brightness without requiring high purity filtering materials
Solution Approach 2:
The patent converts the potential harm of light overlap between different color LEDs into a benefit by designing filtering layers with transmission spectra that deliberately avoid overlapping regions. This approach transforms the problem of spectral interference into an opportunity to optimize light transmission, allowing the system to achieve both effective color separation and high overall light transmission efficiency
3Ease of manufacture
If transmission spectrum of filtering layer overlaps with emission spectrum of another color LED, then light filtering effect deteriorates, but manufacturing cost is reduced
Solution Approach 1:
The patent achieves the desired light filtering effectiveness not through high purity materials (which would increase cost) but by changing the spectral parameters of the filtering layers. Specifically, the peak wavelengths and FWHM values are optimized so that the transmission spectra of red, green, and blue filtering layers do not overlap with the emission spectra of other color LEDs, providing effective color separation with lower cost materials
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 brightness of the LCD panel by improving light filtering efficiency and reducing manufacturing costs, maintaining the NTSC ratio between 72% and 90% while minimizing the purity of the filtering layers.
Implementation Method 1
a first color filtering layer suitable for filtering the first color light, a second color filtering layer suitable for filtering the second color light, and a third color filtering layer suitable for filtering the third color light
Data Source
AI summary
A liquid crystal display (LCD) module includes a backlight module and an LCD panel. The backlight module has an illumination device for emitting at least a first, a second, and a third color light. The wavelength of the second color light is between 520 nm and 540 nm. The LCD panel is provided to display an image with the first, second and third color lights provided as light sources. The LCD panel includes a color filter having at least a first, a second, and a third filtering layer for filtering the first, second, and third color lights, respectively. The LCD panel also includes a liquid crystal layer disposed next to the color filter. The peak value of a transmission spectrum of the second filtering layer is between 520 nm and 540 nm, and the full width at half maximum of the transmission spectrum of the second filtering layer is between 90 nm and 120 nm.