Gamma Voltage Generator Brightness Adjustment Without Contrast Loss
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Solution Overview
Problem
Current display devices adjust image brightness by amplifying all brightness values, leading to degraded contrast ratio and display quality, as they increase image brightness.
Innovation Solution
A display device and method that adjust brightness by modifying gamma curves rather than altering input video signal brightness, using a microprocessor, memory unit, gamma voltage generator, and driving circuit to generate and apply gamma reference voltages, maintaining contrast ratio and display quality at higher brightness levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If brightness values of input video signals are amplified to increase image brightness, then the brightness of the displayed image is improved, but the contrast ratio and display quality are degraded
Solution Approach 1:
The patent applies parameter changes by modifying the gamma curve parameters instead of directly amplifying brightness values. The gamma voltage generator produces reference voltages based on selected gamma curves, which transform the relationship between video signals and display output. This changes the brightness distribution characteristics without uniformly amplifying all pixel values, thereby improving image brightness while preserving contrast ratio and display quality.
Solution Approach 2:
The patent implements dynamics by providing multiple gamma curves and allowing dynamic selection among them based on different display scenarios. The system can switch between different gamma reference voltage value sets stored in memory, enabling adaptive brightness adjustment that maintains optimal contrast ratio for different viewing conditions while improving image brightness when needed.
2Illumination intensity
If all brightness values including dark state regions are amplified, then the overall brightness is improved, but the grayscale distribution is degraded
Solution Approach 1:
The patent uses parameter changes through gamma curve adjustment to selectively modify brightness across different grayscale regions. Different gamma curves provide different transformation characteristics that can enhance overall brightness while preserving the relative relationships between dark, mid, and bright tones. This maintains grayscale distribution stability unlike uniform amplification which distorts all regions equally.
Solution Approach 2:
The patent applies local quality by having different gamma curves optimized for different display needs. Each gamma curve provides a unique brightness transformation profile that can selectively enhance certain grayscale regions while preserving others. This allows targeted brightness improvement in specific areas of the grayscale spectrum while maintaining overall grayscale distribution integrity.
Data Source
AI summary
Provided is a display device capable of brightness adjustment by adjusting gamma curves thereof, without adjusting brightness of input video signals. The display device includes a memory unit, storing a plurality of gamma reference voltage value sets in accordance with a plurality of gamma curves; a microprocessor, for selecting one of the gamma reference voltage value sets stored in the memory unit; a gamma voltage generator, for generating a plurality of gamma reference voltages in response to the selected gamma reference voltage value set from the microprocessor; a data converter, for converting input video signals into video voltages in response to the gamma reference voltages provided from the gamma voltage generator; and a display panel, for displaying images in response to the video voltages from the data converter.