Local Dimming Backlight Control for Warped Curved Displays
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Solution Overview
Problem
Display devices with curved screens, such as automotive HUDs, suffer from image distortion due to curvature, which degrades user experience by making it difficult to extract information from distorted images.
Innovation Solution
Implement image warping to correct curvature-induced distortion by incorporating black pixel regions into the image, and use a 2D array of light sources with local dimming to maintain luminance levels, compensating for luminance decreases at edges caused by black pixels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If image warping is performed to correct distortion on curved display screens, then image clarity is improved, but luminance decreases at the edges of the display
Solution Approach 1:
The patent applies local quality by differentiating the treatment of different display regions. The display area is divided into a first region (containing black pixels from image warping) and a second region (normal display area). The backlight device applies different luminance levels to these regions, with higher luminance in the second region to compensate for the luminance decrease caused by image warping in the first region.
Solution Approach 2:
The patent changes the luminance parameter of the backlight device dynamically based on the display content and region. The controller adjusts the luminance levels of different backlight regions according to the black pixel pattern data, increasing luminance in regions where image warping causes brightness loss while maintaining appropriate luminance in other areas.
2Illumination intensity
If local dimming is implemented to maintain luminance levels, then luminance uniformity is improved, but power consumption increases
Solution Approach 1:
The patent segments the backlight device into multiple independently controllable regions corresponding to different display areas. This segmentation allows selective activation of backlight regions - only the regions requiring compensation (second region with normal display content) are activated at high luminance, while regions with black pixels (first region) use reduced luminance, thereby reducing overall power consumption compared to uniform high luminance.
Solution Approach 2:
The patent applies partial action by selectively applying luminance compensation only where needed (in the second region with normal display content) rather than uniformly across the entire display. This partial application of high luminance maintains image quality where required while minimizing energy consumption by using lower luminance in regions where black pixels are present.
3Measurement precision
If black pixel regions are added to correct image warping distortion, then image accuracy is improved, but dynamic contrast ratio deteriorates
Solution Approach 1:
The patent applies local quality by providing enhanced luminance specifically in the second region where normal display content is shown, while allowing reduced luminance in the first region with black pixels. This localized luminance enhancement maintains the dynamic contrast ratio for the actual image content (in the second region) while accepting lower contrast in the black pixel regions, thereby preserving overall image quality and accuracy.
Data Source
AI summary
A method includes processing input image data to produce resulting image data corresponding to a resulting image such that a first region of the resulting image is filled with black pixels. The method further includes driving a display panel based on the resulting image data. The method further includes producing black pixel pattern data indicative of an arrangement of the black pixels in the resulting image. The method further includes controlling, based on the resulting image data and the black pixel pattern data, luminance levels of one or more of a plurality of light sources of a backlight device configured to illuminate the display panel.