Dynamic Gamma Regulation in LED-Backlit LCD Displays
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Solution Overview
Problem
Conventional LCD displays with static gamma characteristics fail to provide adequate luminance due to their inability to respond to changes in backlight brightness, resulting in low-quality images, especially when using LED-based backlighting, as they rely on a fixed gamma value that does not dynamically adjust to image content.
Innovation Solution
The system synchronizes data writing to pixels with backlight illumination within a video frame, determining gamma values and applying corresponding gamma reference voltages to adjust the gamma characteristic dynamically, allowing for spatial and temporal adjustments of luminance based on image content and backlight intensity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a static gamma characteristic is used in LED-backlit LCD displays, then the device complexity is reduced, but the image quality deteriorates due to inadequate luminance response to backlight brightness changes
Solution Approach 1:
The patent applies dynamics by transitioning from a static gamma characteristic to a dynamic one that changes within each video frame. The gamma characteristic is adjusted based on the spatial and temporal distribution of backlight brightness, allowing the display to adapt to varying illumination conditions and produce high-quality images across different display regions.
Solution Approach 2:
The patent implements parameter changes by modifying the gamma value parameter dynamically. Different gamma values are applied to different regions of the display based on the local backlight intensity, enabling precise control of luminance characteristics to match the intended image content in each region.
2Adaptability or versatility
If gamma characteristic is adjusted frame-by-frame, then the adaptability to backlight changes is improved, but the response speed is insufficient to produce rich imagery
Solution Approach 1:
The patent applies segmentation by dividing the display into multiple regions that can be independently controlled. Each region has its own gamma characteristic that can be adjusted based on local backlight conditions, allowing fine-grained control within a single frame rather than waiting for the next frame cycle.
Solution Approach 2:
The patent introduces a spatial dimension to gamma control by applying different gamma values to different spatial regions of the display. This spatially-resolved gamma adjustment enables simultaneous optimization across the entire display area, transcending the temporal limitation of frame-by-frame adjustment.
3Use of energy by moving object
If LED backlighting is used to reduce power consumption, then energy efficiency is improved, but the gamma characteristic control becomes insufficient due to dynamic backlight brightness changes
Solution Approach 1:
The patent implements feedback by using the known backlight brightness distribution (which is controlled or measured) to adjust the gamma characteristic accordingly. This closed-loop approach ensures that the display luminance accurately reflects the intended image content despite variations in backlight intensity, maintaining high image quality while benefiting from LED energy efficiency.
Data Source
AI summary
System(s) and method(s) are provided for regulation of gamma characteristic of a display having solid-state-based backlight illumination. Regulation of the gamma characteristic can be accomplished at least in part through synchronization of data writing to a set of pixels in a display within a video frame with backlight illumination of a region of the display during a predetermined period, wherein the region is spanned by the set of pixels. Collection of data indicative of illumination intensity of light to be emitted in a region of a backlight source of the display during the predetermined period enables determination of at least one gamma value and at least one gamma reference voltage related to the at least one gamma value. Application of the at least one gamma reference voltage to the set of pixels adjusts the gamma characteristic thereof within the video frame.