Mobile Stylus System Power Reduction via Dynamic Capacitive Line Scanning
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Solution Overview
Problem
Conventional touchscreen systems with active styluses consume excessive power due to finer sensing precision, which is unnecessary when input is received from a finger, leading to wasteful power consumption.
Innovation Solution
Implementing a mobile stylus system that selectively scans only a subset of capacitive lines in a capacitive sensing panel when input is determined to be from a finger, reducing power consumption by switching to a 'finger mode' with less scanning, and scanning more lines when in 'pen mode' for stylus input.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If finer sensing precision is used to detect stylus input, then input precision is improved, but power consumption increases
Solution Approach 1:
The patent implements dynamic scanning by adjusting the number of capacitive lines scanned based on detected input type. When finger input is detected, the system scans fewer lines to reduce power consumption. When stylus input is detected, the system scans more lines to maintain high measurement precision. This dynamic adaptation resolves the contradiction between precision and power consumption.
Solution Approach 2:
The system changes the scanning parameter (number of capacitive lines scanned) based on the detected input type. For finger touches, a reduced scanning parameter is used, while for stylus input, a higher scanning parameter is applied. This parameter adjustment allows the system to optimize between precision and power consumption for different input scenarios.
2Measurement precision
If all capacitive lines are scanned continuously, then measurement precision is maintained, but power consumption increases
Solution Approach 1:
The patent applies partial scanning by scanning only a subset of capacitive lines when finger input is detected, rather than scanning all lines continuously. This partial action reduces power consumption while maintaining sufficient precision for finger input. When stylus input is detected, the system transitions to scanning more lines to ensure adequate precision.
Solution Approach 2:
The scanning intensity dynamically adjusts based on input type detection. The system transitions between low-scanning mode for finger input and high-scanning mode for stylus input, optimizing the balance between measurement precision and energy loss for each scenario.
3Measurement precision
If finer sensing precision is implemented for stylus input, then input precision is improved, but device complexity increases
Solution Approach 1:
The patent implements a universal sensing system that handles both finger and stylus input using the same capacitive sensing panel and control circuitry. The system adapts its scanning behavior based on detected input type, allowing a single sensing system to serve multiple functions with different precision requirements, thereby avoiding the need for separate sensing circuits for each input type.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach significantly reduces power consumption by optimizing scanning based on input type, ensuring efficient power management without compromising input precision.
Implementation Method 1
a capacitive sensing panel, which includes a plurality of capacitive lines arranged in a pattern
Data Source
AI summary
Various embodiments reduce power consumption in a mobile stylus system by selectively scanning only a subset of capacitive lines in a capacitive sensing panel when a received input is determined to be provided by a finger. When the input is determined to be from a stylus, a larger number of capacitive lines can be scanned. Thus, power savings are achieved because less capacitive lines are scanned when the input is determined to be provided by a finger.