Hybrid Capacitive Sensing for Latency Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Capacitive sensing input devices experience latency in detecting input objects due to the nature of object location and interaction with sensor electrode patterns, leading to false readings and delayed recognition, particularly when objects enter the sensing region during or after a transcapacitive image frame scan.
Innovation Solution
Implementing hybrid sensing, which combines absolute capacitive sensing and transcapacitive sensing to determine the location of input objects, allowing for quicker detection and reducing latency by using absolute capacitive sensing to guide the drive order and timing of transcapacitive sensing, ensuring accurate and timely recognition of input objects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If transcapacitive sensing is used to detect input objects, then measurement precision is improved, but latency increases due to the scanning process taking time
Solution Approach 1:
The patent applies preliminary action by performing absolute capacitive sensing before transcapacitive sensing to detect input objects. The absolute capacitive sensing serves as a preliminary detection mechanism that can immediately respond to input objects without waiting for the complete transcapacitive scanning process, thereby reducing detection latency while maintaining the precision benefits of transcapacitive sensing when activated.
Solution Approach 2:
The patent segments the sensing process into two distinct parts: absolute capacitive sensing and transcapacitive sensing. By segmenting the detection function, the system can use absolute capacitive sensing for rapid initial detection and only engage transcapacitive sensing when necessary, optimizing both speed and precision without the latency penalty of continuous scanning.
2Measurement precision
If continuous scanning is performed to detect input objects, then measurement precision is maintained, but device complexity increases
Solution Approach 1:
The patent applies dynamics by making the sensing system adaptive rather than static. The system dynamically switches between absolute capacitive sensing and transcapacitive sensing based on detection needs. Absolute capacitive sensing is used for general detection, while transcapacitive sensing is activated only when additional precision is required, optimizing the balance between measurement precision and system complexity.
Solution Approach 2:
The patent extracts the rapid detection function from the complex transcapacitive sensing process by separating it into a distinct absolute capacitive sensing mechanism. This extraction allows the system to perform basic detection operations without engaging the more complex scanning process, thereby reducing overall system complexity while maintaining detection capability.
3Productivity
If transcapacitive sensing drive order is optimized, then productivity is improved, but measurement precision may be compromised
Solution Approach 1:
The patent uses absolute capacitive sensing as a preliminary action that provides immediate detection results without requiring optimized drive orders for transcapacitive sensing. This preliminary detection layer enables fast response times while the transcapacitive sensing with its optimized drive order can be applied selectively when higher precision is needed, resolving the contradiction between productivity and measurement precision.
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
Hybrid sensing significantly reduces latency in detecting input objects by utilizing faster absolute capacitive sensing to trigger and direct transcapacitive sensing, resulting in more accurate and timely recognition of input objects within the sensing region.
Implementation Method 1
The sensor module is configured to acquire changes in absolute capacitance from a first plurality of sensor electrodes of a sensor electrode pattern
Implementation Method 2
The sensor module is also configured to utilize the changes in absolute capacitance to determine a drive order in which to drive sensor electrodes of the first plurality of sensor electrodes to acquire changes in transcapacitance between the first plurality of sensor electrodes and a second plurality of sensor electrodes of the sensor electrode pattern
Data Source
AI summary
A processing system comprises a sensor module and a determination module. The sensor module is configured to acquire changes in absolute capacitance from a first plurality of sensor electrodes of a sensor electrode pattern. The sensor module is also configured to utilize the changes in absolute capacitance to determine a drive order in which to drive sensor electrodes of the first plurality of sensor electrodes to acquire changes in transcapacitance between the first plurality of sensor electrodes and a second plurality of sensor electrodes of the sensor electrode pattern. The determination module is configured to determine positional information for an input object in a sensing region of the capacitive sensing device based on the changes in transcapacitance.