Filterless LCD Backlight Using Time-Sequential Color Emission
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional liquid crystal display (LCD) devices require multiple color filters, which can lead to light loss and increased production costs, as they block portions of desired colors near their cutoff wavelengths, affecting brightness and efficiency.
Innovation Solution
The LCD device configures a backlight to simultaneously emit two colors and separately emit a third color at a different time, using liquid crystal shutters and filters to control light passage, allowing the third color to be displayed without a filter, thereby reducing light loss and production costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple color filters are used in conventional LCD devices, then color accuracy is improved, but light loss increases and brightness decreases
Solution Approach 1:
The patent removes one color filter from the conventional three-filter LCD structure. Specifically, the green color filter is eliminated, and instead a green light-emitting LED is integrated into the backlight unit. This extraction of the unnecessary filter reduces light loss while maintaining color accuracy through the combination of remaining filters and the added LED light source.
Solution Approach 2:
The patent merges the function of the green color filter with a green light-emitting LED in the backlight unit. By combining these two elements, the system achieves green color display without requiring a green color filter in the liquid crystal panel, thereby reducing overall light loss while maintaining color accuracy.
2Measurement precision
If multiple color filters are used in conventional LCD devices, then color accuracy is improved, but production costs increase
Solution Approach 1:
The patent extracts and eliminates one color filter from the conventional three-filter structure, reducing the number of manufacturing steps and materials required. This simplification lowers production costs while color accuracy is maintained through the integrated LED approach.
Solution Approach 2:
The backlight unit is designed with multi-functionality, incorporating red, green, and blue light-emitting LEDs that can independently or simultaneously provide all three primary colors. This universal backlight design eliminates the need for corresponding color filters in the panel, reducing manufacturing complexity and cost while maintaining color accuracy.
3Measurement precision
If color filters block light near cutoff wavelengths, then color purity is improved, but light loss increases and efficiency decreases
Solution Approach 1:
The patent removes the green color filter that causes light loss near its cutoff wavelengths. By extracting this filter and replacing its function with a green LED in the backlight, the system eliminates the energy loss associated with filtering while maintaining green color purity through direct LED emission.
Solution Approach 2:
The patent changes the approach to color generation from passive filtering to active light emission. By using LEDs that emit specific wavelengths directly rather than filtering broad-spectrum light, the system achieves color purity without the energy loss inherent in filtering processes.
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 brightness and efficiency by eliminating the need for one color filter, providing improved image quality and reducing production expenses while maintaining a comparable refresh rate to conventional LCDs.
Implementation Method 1
The LCD screen includes an array of red, green, and blue (RGB) color filters 130, and a corresponding array of liquid crystal shutters 120
Implementation Method 2
The red color filter 130r is configured to allow passage of red light, but prevent passage of green and blue light
Data Source
AI summary
A liquid crystal display (LCD) device includes a backlight configured to emit first, second, and/or third colors of light, and a backlight controller. The backlight controller is configured to activate the backlight to simultaneously emit the first and second colors of light to generate a first image component including a combination of first color image data and second color image data, and to separately emit the third color of light at a different time than the first and second colors of light to generate a second image component including third color image data. The LCD device is configured to display the first and second image components to provide a single image frame. Related devices and methods of operation are also discussed.