Backlight Control Circuit for Display Contrast Enhancement
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Solution Overview
Problem
Existing display technologies face issues with distorted details and reduced contrast when reducing backlight intensity, as compensation of display data can exceed maximum values, leading to clamped luminance and loss of image details.
Innovation Solution
A control circuit and method that includes a statistics circuit, backlight determining circuit, and backlight control circuit to calculate and adjust backlight intensities for blocks in a display, allowing for increased luminance and compensation gains to enhance contrast without exceeding power limits, using luminance statistical information to determine optimal backlight control and image compensation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If backlight intensity is reduced for regions with lower luminance to achieve power saving, then power consumption is reduced, but compensation of display data may exceed maximum value causing loss of image details
Solution Approach 1:
The display screen is divided into multiple blocks, and each block is independently analyzed for its luminance characteristics. The backlight module is segmented into corresponding backlight blocks that can be controlled independently. This segmentation allows selective backlight intensity adjustment per block, enabling power saving in dark regions while maintaining sufficient brightness in bright regions to prevent compensation clipping and preserve image details.
Solution Approach 2:
Different backlight intensities are applied to different blocks based on their local luminance requirements. Blocks with lower average luminance receive reduced backlight intensity for power saving, while blocks with higher average luminance maintain or receive increased backlight intensity to prevent compensation value clipping. This local quality approach ensures image details are preserved in regions where they are most needed while reducing overall power consumption.
2Use of energy by moving object
If backlight intensity is reduced for regions with lower luminance, then power consumption is reduced, but contrast of the image is reduced
Solution Approach 1:
The backlight intensity for each block is dynamically adjusted based on the average luminance of pixels in that block. Blocks with higher average luminance receive proportionally higher backlight intensity, while blocks with lower average luminance receive reduced intensity. This dynamic adaptation maintains local contrast relationships across different regions of the display while optimizing overall power consumption.
Solution Approach 2:
The backlight intensity parameter is changed on a per-block basis according to the luminance characteristics of each block. By modifying the backlight intensity parameter locally rather than globally, the system maintains image contrast in regions where it matters most while reducing power consumption in regions where full brightness is not needed.
3Stability of the object's composition
If maximum power is evenly distributed on light emitting elements, then uniform backlight intensity is achieved, but brighter blocks cannot exceed maximum luminance to enhance contrast
Solution Approach 1:
Instead of uniform backlight intensity across the entire display, the system applies local quality by assigning different backlight intensities to different blocks based on their luminance requirements. Blocks that benefit from contrast enhancement receive higher backlight intensity, while other blocks receive lower intensity, optimizing both contrast and power efficiency.
Solution Approach 2:
The backlight intensity distribution transitions from a static uniform pattern to a dynamic non-uniform pattern that adapts to the content being displayed. The system dynamically determines which blocks need enhanced brightness for contrast improvement and adjusts backlight intensity accordingly, allowing brighter blocks to exceed the uniform maximum luminance level when beneficial for image quality.
Data Source
AI summary
A control method of a display includes a statistics circuit, a backlight determining circuit and a backlight control circuit. The display includes a backlight module having a maximum luminance. The statistics module receives frame, and generates luminance statistical information of a plurality of blocks included in the frame. The backlight determining circuit determines a backlight intensity corresponding to each of the blocks according to the luminance statistical information of the blocks and the maximum luminance. At least one of the backlight intensities corresponding to the blocks is greater than a normal luminance, which is a backlight intensity corresponding to one of the blocks when a maximum power is evenly distributed on light emitting elements of the display. The backlight control circuit controls the luminance of the backlight module according to the backlight intensities.