Gamma Voltage Generation Unit for Display Visibility
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Solution Overview
Problem
Existing display devices face challenges in maintaining visibility across varying light conditions without causing data loss or image distortion, particularly in mobile terminals, where brightness adjustment methods like data modulation lead to limited brightness enhancement and decreased contrast ratios.
Innovation Solution
A gamma voltage generation unit that includes a voltage booster, mode selector, and gamma voltage adjusters to generate and adjust gamma voltages based on detected light quantities, preventing data loss and image distortion while maintaining contrast ratio by performing gamma modulation for a high gray scale range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If data modulation is used to enhance visibility in low light conditions, then visibility is improved, but data loss and image distortion occur
Solution Approach 1:
The patent changes the parameter being modulated from data signals to gamma voltages. Instead of modifying data signal values to enhance brightness, the system adjusts gamma voltage parameters (V255, V191, V127) that control the luminance output of the display. This parameter substitution allows brightness enhancement without corrupting the original data information.
2Illumination intensity
If data modulation is used to enhance visibility, then brightness can be increased, but the number of modes is limited and brightness cannot exceed a critical value
Solution Approach 1:
The patent implements dynamic gamma voltage adjustment where the gamma voltages (V255, V191, V127) are continuously adjustable parameters rather than fixed mode selections. The gamma voltage generation unit can dynamically change these voltages based on ambient light conditions, allowing continuous brightness adaptation beyond discrete mode limitations.
3Illumination intensity
If backlight brightness is increased to enhance visibility, then visibility is improved, but black brightness increases and contrast ratio decreases
Solution Approach 1:
The patent applies local quality adjustment by selectively modifying gamma voltages for different gray scale ranges. The gamma voltage generation unit adjusts voltages specifically for the high gray scale range (using V255, V191, V127) to enhance brightness where needed, while leaving lower gray scale voltages unchanged. This localized adjustment enhances visibility in bright areas without increasing black level brightness, thereby preserving contrast ratio.
4Illumination intensity
If gamma voltage generation unit is added to perform gamma modulation, then visibility is enhanced without data loss, but device complexity increases
Solution Approach 1:
The patent merges the gamma voltage generation functionality into the existing display driver circuitry. The gamma voltage generation unit is integrated with the display device's existing control structures, combining multiple functions (voltage boosting, mode selection, gamma voltage adjustment) into a unified circuit block rather than adding separate independent components.
Data Source
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AI summary
A gamma voltage generation unit is discussed which includes: A maximum reference voltage establisher (210), a minimum reference voltage establisher (310), minimum and maximum reference voltage selectors (318-324), a voltage booster (220) to boost a first maximum reference voltage into at least one second maximum reference voltage, a mode selector (230) configured to select one of the maximum reference voltage and the at least one second maximum reference voltage as a selected maximum reference voltage, and a plurality of gamma voltage adjusters (240, 250, 260, 270, 280, 290). The selected maximum reference voltage selected by the mode selector is provided as a 255th gray-scale gamma voltage (V255). A first gamma voltage adjuster (240) among the gamma voltage adjusters can generate a gray-scale gamma voltage (V191) based on the selected maximum reference voltage. The remaining gamma voltage adjusters (250, 260, 270, 280, 290) are connected to one another in a cascade.