Display Panel Driver Segmentation for Flicker-Free Frequency Adaptation
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Solution Overview
Problem
Display devices experience a deterioration in display quality when the driving frequency is changed, leading to potential flicker recognition and luminance differences in low grayscale levels.
Innovation Solution
A display device with a panel driver that operates at different frequencies in different modes, using a first scan driver for image display in one mode and a second scan driver for resetting the anode of the light emitting element at a consistent frequency, maintaining image quality across frequency changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the panel driver changes the driving frequency to achieve different driving modes, then the adaptability is improved, but the display quality deteriorates due to flicker and luminance differences
Solution Approach 1:
The scan driver is divided into a first scan driver and a second scan driver with different functions. The first scan driver outputs first and second scan signals for normal image display, while the second scan driver outputs a third scan signal specifically for resetting the anode. This segmentation allows independent optimization of each driver's function, enabling frequency adjustment for adaptability while maintaining stable anode reset for display quality.
Solution Approach 2:
The third scan signal from the second scan driver resets the anode of the light emitting element in advance during the blank period, before the next image display cycle begins. This preliminary resetting action ensures that the anode is prepared in a stable state for the upcoming display cycle, preventing flicker and luminance differences even when the overall driving frequency changes.
2Use of energy by moving object
If the driving frequency is reduced in the second driving mode, then the power consumption is reduced, but the anode reset frequency changes causing luminance differences in low grayscale
Solution Approach 1:
The system dynamically adjusts the operating frequency of the first scan driver based on the driving mode, while the second scan driver maintains a fixed frequency for anode reset. This dynamic configuration allows the display to operate at lower frequencies for reduced power consumption while keeping the critical anode reset frequency constant to maintain luminance uniformity in low grayscale levels.
Solution Approach 2:
The invention changes the frequency parameter of the first scan driver between driving modes to optimize power consumption, while independently maintaining the frequency parameter of the second scan driver constant. This selective parameter change allows the system to reduce overall power consumption without affecting the luminance precision that depends on consistent anode reset timing.
3Device complexity
If the panel driver uses a single scan driver for both image display and anode reset, then the device complexity is reduced, but the ability to maintain consistent anode reset frequency across different driving modes is compromised
Solution Approach 1:
The scan driver functionality is segmented into two independent drivers: the first scan driver handles image display scanning, and the second scan driver handles anode reset. This segmentation enables each driver to be optimized independently - the first can change frequency for different driving modes while the second maintains a constant frequency for reliable anode reset, solving the adaptability issue without excessive complexity.
Solution Approach 2:
While segmented, both scan drivers work together within the unified pixel circuit structure to achieve multi-functionality. The first scan driver provides adaptive frequency operation for different display modes, while the second scan driver provides stable anode reset functionality. Together, they enable the system to adapt to different driving conditions while maintaining display quality.
Data Source
AI summary
A display device includes a display panel including a pixel and a panel driver which drives the display panel at a first panel frequency in a first driving mode and drives the display panel at a second panel frequency in a second driving mode. The pixel includes a light emitting element and first, second, third, and fourth transistors. The first transistor is connected between a power line and the light emitting element. The second transistor is connected between a data line and the first transistor and receives a first scan signal. The third transistor is connected between the first transistor and an initialization voltage line and receives a second scan signal. The fourth transistor is connected between the first transistor and a reset voltage line and receives a third scan signal. The third scan signal is inactivated in the first driving mode and is activated in the second driving mode.