Capacitive Sensor Artifact Filtering for Input Accuracy
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Solution Overview
Problem
Existing input devices, such as touchpads and touch screens, face challenges in distinguishing between actual input object signals and artifact responses, leading to inaccurate reporting of positional and force information to computing systems.
Innovation Solution
A method and system that utilize capacitive sensing to generate a capacitive image of a sensing region, identify an object signal value, and determine an artifact threshold to differentiate between object and artifact responses, thereby excluding artifact information from reports to computing systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If capacitive sensing is used to detect input objects, then the sensing capability is improved, but artifact responses are generated that reduce measurement precision
Solution Approach 1:
The patent extracts and removes artifact information from the capacitive image data before processing. By identifying and excluding artifact responses (such as those from environmental factors or sensor noise), the system retains only valid input object signals, thereby improving measurement precision while maintaining the enhanced sensing capability provided by capacitive sensing.
Solution Approach 2:
The patent introduces an intermediary processing stage that analyzes capacitive images and distinguishes between valid object signals and artifact responses. This intermediary layer (the artifact detection and exclusion mechanism) mediates between the raw capacitive sensing data and the final processed output, filtering out harmful artifacts while preserving useful information.
2Reliability
If artifact information is included in reports, then device complexity is reduced, but reliability of input data deteriorates
Solution Approach 1:
The patent performs preliminary action by analyzing and filtering capacitive images before they are used for input detection. By pre-identifying and excluding artifact responses in advance, the system ensures that only reliable input object information is included in reports, improving data reliability while managing complexity through efficient preprocessing.
Solution Approach 2:
The patent employs feedback mechanisms where the system continuously monitors capacitive sensor outputs, compares them against established criteria to identify artifacts, and adjusts processing accordingly. This feedback loop ensures high reliability by validating input data quality and excluding artifacts, while the automated nature of the feedback process manages complexity efficiently.
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 enhances the accuracy of input device reporting by filtering out artifact responses, improving the usability and reliability of input devices by ensuring that only valid input object information is transmitted to the host device.
Implementation Method 1
A proximity sensor device or other input device may utilize any combination of sensing elements and/or sensing techniques. For example, the input device may utilize any combination of capacitive, elastive, resistive, inductive, magnetic, acoustic, ultrasonic, and/or optical sensing elements and/or sensing techniques.
Implementation Method 2
obtain, from various sensor electrodes, a capacitive image of a sensing region. The capacitive image describes changes in variable capacitance among the sensor electrodes.
Data Source
AI summary
A method of capacitive sensing that may include obtaining, from various sensor electrodes, a capacitive image of a sensing region. The capacitive image may describe changes in variable capacitance among the sensor electrodes. The method may further include identifying an object signal value within the capacitive image. The object signal value may be identified from an object response that is produced by an input object that is proximate to the sensor electrodes. The method may further include determining, using the object signal value of the object response, an artifact threshold that identifies an artifact response within the capacitive image. The method may further include excluding, using the artifact threshold, artifact information regarding the artifact response from a report to a computing system.