Source Driver Mode Adjustment for Pixel Settling in Integrated Displays
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Integrated display and capacitive sensing devices face challenges in minimizing display artifacts due to differences in pixel settling between blanking and display update periods, leading to suboptimal user input detection and display quality.
Innovation Solution
The method involves driving sensor electrodes for capacitive sensing during a blanking period and using source drivers to update display lines during both blanking and display update periods, with a controller adjusting the operational mode of source drivers to equalize pixel settling between these periods, thereby mitigating display artifacts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If pixel settling time is extended to improve display quality, then display artifacts are reduced, but input sensing responsiveness deteriorates
Solution Approach 1:
The frame period is segmented into distinct time intervals: a first time interval for updating a first subset of display lines during which capacitive sensing is inhibited, and a second time interval for updating a second subset of display lines during which capacitive sensing is enabled. This segmentation allows pixel settling to occur during the first interval without compromising input sensing responsiveness during the second interval.
Solution Approach 2:
The system dynamically switches between different operational modes for different subsets of display lines. During the first time interval, source drivers operate in a mode that prioritizes pixel settling for the first subset of lines. During the second time interval, the system transitions to a mode that enables both capacitive sensing and updating of the second subset of lines, thereby adapting to different performance requirements at different times.
2Measurement precision
If capacitive sensing is performed during the entire frame period, then input sensing accuracy is improved, but display update performance deteriorates
Solution Approach 1:
The frame period is divided into segments where capacitive sensing is enabled only during the second time interval when the second subset of display lines is being updated. During the first time interval, capacitive sensing is inhibited to allow uninterrupted pixel settling. This segmentation ensures that input sensing accuracy is maintained during the second interval while display update performance is preserved during the first interval.
Solution Approach 2:
Capacitive sensing is performed periodically during specific time intervals (the second time interval) rather than continuously throughout the entire frame period. This periodic action allows the system to balance between input sensing accuracy and display update performance by enabling sensing only when it does not interfere with critical pixel settling operations.
3Speed
If pixel settling time is reduced to improve input sensing responsiveness, then input sensing speed is improved, but display artifacts increase
Solution Approach 1:
Display lines are segmented into two subsets: a first subset updated during the first time interval where pixel settling is prioritized to minimize artifacts, and a second subset updated during the second time interval where input sensing is enabled. This segmentation allows the system to reduce overall pixel settling time while maintaining display quality for the first subset and enabling responsive input sensing during the second subset update.
Solution Approach 2:
Different quality requirements are applied to different subsets of display lines. The first subset of display lines is updated with a focus on minimizing display artifacts through extended pixel settling time during the first time interval. The second subset of display lines is updated during the second time interval with simultaneous capacitive sensing, accepting slightly different quality characteristics to enable responsive input sensing. This local quality approach allows the system to optimize for different goals in different regions of the display update process.
Data Source
AI summary
An example method of performing capacitive sensing and display updating in an integrated capacitive sensing device and display device includes driving a plurality of sensor electrodes of the capacitive sensing device for input sensing during a blanking period. The method further includes driving a plurality of source lines using a plurality of source drivers during the blanking period to update a first display line of the display device. The method further includes driving the plurality of source lines using the plurality of source drivers during a display update period to update one or more additional display lines of the display device. The method further includes adjusting an operational mode of the plurality of source drivers during the blanking period to equalize display pixel settling between the blanking period and the display update period.