Display Panel Driving Device Gamma Voltage Adjustment
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Solution Overview
Problem
The display quality of liquid crystal display (LCD) devices is degraded due to the response speed of the liquid crystal and leakage current when the driving frequency is changed, leading to issues such as brightness variation and image defects.
Innovation Solution
A driving device for a display panel that includes a timing controller, a gamma data provider, a data driver, and a gate driver, which determines the driving frequency based on the number of counting signals during active and blank periods of a vertical synchronized signal, and outputs specific gamma data sets to maintain consistent gamma voltages, preventing frequency changes that cause brightness variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the driving frequency of the LCD device is changed, then the response speed of the liquid crystal may be improved, but brightness variation and image defects occur due to leakage current
Solution Approach 1:
The patent changes the gamma voltage parameter based on the detected driving frequency. The gamma data provider selects different gamma data sets (first, second, or third) corresponding to different frequency ranges, thereby adjusting the gamma voltage to compensate for leakage current effects at various driving frequencies and maintain consistent display quality
Solution Approach 2:
The patent implements a feedback mechanism where the driving frequency is continuously monitored through counting signals during active and blank periods. Based on this feedback, the gamma data provider dynamically selects appropriate gamma data sets to maintain optimal display performance across varying frequency conditions
2Productivity
If the driving frequency is increased to improve productivity, then the display refresh rate is improved, but brightness variation occurs due to liquid crystal response limitations and leakage current
Solution Approach 1:
The patent adjusts the gamma voltage parameter according to the driving frequency. When high refresh rates are detected, specific gamma data sets are selected to compensate for the increased leakage current and liquid crystal response limitations, thereby maintaining brightness consistency across different productivity levels
3Reliability
If gamma voltage is adjusted to compensate for leakage current, then display quality is improved, but additional control complexity is introduced
Solution Approach 1:
The patent segments the gamma data into multiple distinct data sets (first, second, and third gamma data sets) corresponding to different frequency ranges. This segmentation allows the system to select pre-defined gamma characteristics based on detected frequency, simplifying the control logic compared to continuous adjustment while maintaining display quality across varying conditions
Solution Approach 2:
The patent changes discrete gamma voltage parameters based on detected driving frequency. By using predetermined gamma data sets rather than continuous adjustment, the patent achieves display quality compensation with relatively simple control logic, selecting from predefined parameter sets based on frequency thresholds
Data Source
AI summary
A driving device of a display panel includes a timing controller which converts a first image data to a second image data, and generates control signals that control a driving timing of the second image data, a gamma data provider which determines a driving frequency of the second image data based on the number of a counting signal output during an active period and a blank period of a vertical synchronized signal, and outputs one of gamma data sets based on the driving frequency, a data driver which generates a data signal corresponding to the second image data based on the one of the gamma data set, and provides the data signal to a data line of a display panel based on the control signals, and a gate driver which provides the gate signal to a gate line of the display panel based on the control signals.