Gamma Voltage Generating Circuit Uniformity for Display Panels
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Solution Overview
Problem
In large-sized display panels using multiple data driver ICs, the gamma voltage generating circuits in each IC generate different gray scale voltages due to offset voltages from operational amplifiers, leading to luminance unevenness across the display panel.
Innovation Solution
A gamma voltage generating circuit with multiple sub-circuits, each including a resistive voltage divider and a voltage modification module, ensures that gamma reference voltages at the same gray scale are uniform across all sub-circuits by adjusting voltages based on differences between corresponding sub-circuits, using comparators and operational amplifiers to maintain consistent voltage ratios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If multiple data driver ICs are used to control large-sized display panels, then the display panel can be driven effectively, but luminance unevenness occurs across the display panel due to offset voltages from operational amplifiers in each IC's gamma voltage generating circuit
Solution Approach 1:
The patent merges multiple gamma voltage generating circuits into a single shared gamma voltage generating circuit that serves all data driver ICs. This consolidation ensures that all data driver ICs receive identical gamma reference voltages, eliminating the luminance unevenness caused by offset voltages from separate operational amplifiers in each IC's individual circuit.
Solution Approach 2:
The patent introduces an intermediary voltage collecting line that collects gamma reference voltages from multiple data driver ICs and redistributes them uniformly. This intermediary structure acts as a mediator to ensure consistent voltage distribution across all ICs, preventing luminance variations.
2Adaptability or versatility
If separate gamma voltage generating circuits are used in each data driver IC, then each IC can independently generate gamma voltages, but voltage differences occur between ICs leading to brightness inconsistency
Solution Approach 1:
The patent merges the gamma voltage generation function into a shared circuit that all data driver ICs access through voltage collecting lines. This eliminates voltage differences between ICs while maintaining the ability of each IC to independently receive and use the gamma voltages for its pixel control.
3Reliability
If offset voltages from operational amplifiers are present in each gamma voltage generating circuit, then the circuits can function independently, but luminance unevenness is caused across the display panel
Solution Approach 1:
The patent merges multiple independent gamma voltage generating circuits into a single shared circuit, eliminating the offset voltage problems of individual operational amplifiers. The shared circuit provides uniform gamma reference voltages to all data driver ICs, ensuring luminance uniformity across the entire display panel while maintaining operational reliability.
Data Source
AI summary
A gamma voltage generating circuit includes N gamma voltage generating sub-circuits. Each gamma voltage generating sub-circuit includes a resistive voltage divider circuit and a plurality of gamma reference voltage output terminals. Each resistive voltage divider circuit includes a plurality of resistors connected in series, and any two resistive voltage divider circuits have a same resistance ratio of the plurality of resistors. The N gamma voltage generating sub-circuits include a first gamma voltage generating sub-circuit. The first gamma voltage generating sub-circuit further includes a gamma voltage generation circuit. Output terminals of the gamma voltage generation circuit are electrically connected to a highest gamma reference voltage output terminal and a lowest gamma reference voltage output terminal, respectively. Highest gamma reference voltage output terminals of the gamma voltage generating sub-circuits are connected, and lowest gamma reference voltage output terminals of the gamma voltage generating sub-circuits are connected.