Display Driver Subframe Segmentation for Flicker Reduction
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Solution Overview
Problem
Conventional display drivers for LED displays experience significant screen flickering, especially at low pixel data, due to the division of frame periods into subframe periods, which does not adequately address the issue of display flicker.
Innovation Solution
The display driver employs multiple driving channels to output driving signals in a pulse width modulation manner, dividing the frame period into subframe periods and further subdividing these into scan line periods, allowing for alternative subframe period combinations to reduce non-illuminating intervals and increase refresh rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the frame period is divided into subframe periods for PWM driving, then the display driver can control pixel illumination duration, but the screen flickering becomes more obvious especially at low pixel data
Solution Approach 1:
The invention segments the pixel array into multiple groups and divides the frame period into multiple subframe periods. Different groups of pixels are driven in different subframe periods, allowing the display to maintain higher refresh rates while controlling individual pixel illumination duration through PWM modulation. This segmentation approach distributes the flicker effect across multiple groups, reducing visible flickering compared to uniform subframe driving.
Solution Approach 2:
The invention implements periodic action by cycling through different subframe period combinations for different driving channels. Each driving channel outputs driving signals in alternating subframe period combinations, creating a periodic pattern that increases the effective refresh rate. This periodic modulation helps eliminate flicker by ensuring that no single group of pixels remains off for extended periods.
2Stability of the object's composition
If conventional subframe periods are used to drive the entire pixel array evenly, then the display can maintain uniform illumination, but the refresh rate remains limited and flickering persists at extreme low pixel data
Solution Approach 1:
The pixel array is segmented into multiple groups that can be driven independently in different subframe periods. This allows the display to maintain uniform overall illumination while achieving higher effective refresh rates by cycling through different group combinations. The segmentation enables parallel driving of multiple pixel groups, increasing productivity without sacrificing illumination uniformity.
Solution Approach 2:
The invention introduces dynamic subframe period combinations where different driving channels operate with different subframe period assignments. This dynamic approach allows the system to adaptively increase refresh rates for different regions of the pixel array while maintaining uniform illumination characteristics. The dynamic switching between subframe combinations eliminates the static limitation of conventional uniform subframe driving.
3Device complexity
If driving signals are output in traditional subframe periods, then the display driver can simplify control logic, but the non-illuminating time intervals between subframe periods cause visible flicker
Solution Approach 1:
The display driver segments the pixel array into multiple groups, each driven by different driving channels with different subframe period combinations. This segmentation allows the control logic to remain relatively simple while reducing non-illuminating time intervals through overlapping subframe periods. Different groups are activated at different times, ensuring continuous illumination across the entire display.
Solution Approach 2:
The invention achieves continuity of useful action by designing subframe period combinations that overlap in time. While one group of pixels is being driven in a given subframe period, another group is already being prepared or is being driven in a different subframe period. This overlapping approach ensures that there are minimal or no non-illuminating intervals, eliminating visible flicker while maintaining simple control logic.
Data Source
AI summary
A display driver for driving a display device including a pixel array is provided. The display driver includes a plurality of driving channels. The driving channels is configured to output driving signals in a pulse width modulation manner to drive the pixel array to illuminate in a first frame period which is being divided into a plurality of subframe periods. A first driving channel of the plurality of driving channels outputs a first driving signal in a first subframe period combination. A second driving channel of the plurality of driving channels outputs a second driving signal in a second subframe period combination different than the first subframe period combination. Each of the first subframe period combination and the second subframe period combination comprises at least one subframe period of the first frame period.