Touch Controller Scan Rate Adjustment for Display Latency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Portable electronic devices with touch-sensitive displays face challenges in efficiently detecting touches and reducing latency in display updates due to limited space and the need for optimized scanning methods.
Innovation Solution
The method involves detecting touches on a touch-sensitive display, determining the time of the next display update, and adjusting the scan length and rate to ensure timely reporting of touch data, using a touch controller to adjust the number of pulses in each frame and potentially grouping pulses to reduce scan time, thereby minimizing latency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the scan rate is increased to improve touch detection speed, then responsiveness is improved, but the time available for display updates is reduced
Solution Approach 1:
The patent implements dynamic adjustment of scan parameters by monitoring display update timing and adapting the scan rate accordingly. When display updates are imminent, the system reduces scan activity to ensure timely reporting of touch data, while maintaining higher scan rates during stable display periods to improve touch responsiveness.
Solution Approach 2:
The system changes operational parameters (scan rate, pulse timing) based on the timing of display updates. By adjusting these parameters dynamically, the system optimizes the balance between touch detection speed and display update timing, ensuring that touch data is reported in time for the next display update without unnecessarily sacrificing scan speed.
2Measurement precision
If the scan length is extended to improve touch detection accuracy, then measurement precision is improved, but latency increases
Solution Approach 1:
The patent applies partial scanning strategies where the system scans only the necessary portions of the display at full resolution, or uses reduced scanning intensity when touch precision requirements are lower. This allows the system to maintain acceptable touch detection accuracy while reducing overall scan time and latency.
Solution Approach 2:
The system performs preliminary scanning or uses predictive algorithms to anticipate touch events, allowing it to prepare touch detection data in advance. This preliminary action reduces the need for extended scan lengths while maintaining detection accuracy, as the system is already prepared with relevant data when touches occur.
3Reliability
If the number of pulses per frame is increased to improve touch data completeness, then reliability is improved, but scan time increases
Solution Approach 1:
The patent segments the scanning process into multiple phases or zones, allowing the system to allocate pulses strategically across different display regions. High-priority areas receive more pulses for complete touch data, while lower-priority areas use fewer pulses, maintaining overall reliability without proportionally increasing total scan time.
Solution Approach 2:
The system uses periodic scanning patterns where pulses are distributed in regular intervals rather than continuous sequences. This periodic action allows the display update process to interleave with scanning activities, ensuring touch data completeness while preventing scan time from becoming the bottleneck for display updates.
Data Source
AI summary
A method includes detecting a touch on a touch-sensitive display, determining a time of a display update of the touch-sensitive display, and adjusting a scanning rate of scanning electrodes of the touch-sensitive display based on the time of the display update.