Zone Backlit LCD Border Area Light Diffusion
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Solution Overview
Problem
LCD devices with zone backlighting suffer from a halo border effect due to low contrast ratios and unnecessary power consumption, as perimeter areas of the display panel are illuminated to match central areas, leading to distracting image quality and increased energy use.
Innovation Solution
Implementing a border area between the active and non-image display regions with light-producing elements operating at different power levels, and using a tapering technique to control illumination intensity, where central elements receive a higher power input and perimeter elements receive a lower power input to reduce halo effects and power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If zone backlighting is implemented to reduce power consumption, then power usage is reduced, but a halo border effect is generated due to illumination of perimeter areas
Solution Approach 1:
The patent applies local quality by differentiating the illumination intensity across different regions of the display panel. Specifically, the border area receives a first illumination intensity while the active image display region receives a second, higher illumination intensity. This spatial differentiation allows the border area to be adequately lit without creating the halo effect, while maintaining high contrast in the active region where image quality is critical.
Solution Approach 2:
The patent segments the backlighting system into distinct zones with different illumination characteristics. The display panel is divided into a border area and an active image display region, each controlled independently with different power levels. This segmentation enables selective illumination optimization - reducing power in the border area while maintaining image quality in the active region.
2Illumination intensity
If perimeter areas are illuminated at the same intensity as central areas, then image intensity uniformity is maintained, but image contrast is reduced and viewer comfort deteriorates
Solution Approach 1:
The patent implements local quality by assigning different illumination intensities to different spatial regions. The border area is illuminated at a first intensity level that provides sufficient visibility without creating contrast problems, while the active image display region receives a second, higher intensity level that ensures image quality and contrast. This localized differentiation resolves the contradiction between uniformity and contrast.
3Object-generated harmful factors
If the active image display region is reduced to minimize halo effect, then halo border is reduced, but the display area is reduced
Solution Approach 1:
The patent uses local quality to differentiate the border area from the active image display region through distinct illumination intensities. This allows the border area to extend to the full physical display area while maintaining visual separation from the active region. The border area serves as a transition zone that prevents halo effects without sacrificing display area, as it is clearly demarcated by illumination intensity differences.
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 border area diffuses light, reducing the halo effect and maintaining high contrast, while the tapering technique minimizes power usage by reducing illumination intensity at the perimeter, enhancing image clarity and reducing energy consumption.
Implementation Method 1
the border area is disposed between the active image display region and the non-image display region to diffuse light produced by the light producing elements transmitted through the display panel within the border area
Data Source
AI summary
A liquid crystal display device includes a display panel having an active image display region, a non-image display region surrounding the active image display region, and a border area disposed between the active image display region and the non-image display region, and a backlight device adjacent to the display panel and having a plurality of light producing elements corresponding to the active image display region, wherein the border area is disposed between the active image display region and the non-image display region to diffuse light produced by the light producing elements transmitted through the display panel within the border area.