Multi-Modal Sensing Surface for Touch and Object Identification
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Solution Overview
Problem
Existing multi-touch surfaces that detect user input and identify objects on their surface are either bulky due to optical techniques or inefficient in power consumption when using capacitive and RF sensing technologies together.
Innovation Solution
A multi-modal sensing surface combining a capacitive sensing electrode array and an array of RF antennas, where the RF antennas are tuned to activate and read NFC or RFID tags, allowing for both location and identification of objects while preventing interference with capacitive sensing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If optical techniques are used to detect and identify objects on the surface, then object identification capability is improved, but device size and complexity increase
Solution Approach 1:
The patent combines capacitive sensing electrode array with RF antenna array into a single multi-modal sensing surface. The capacitive electrodes detect touch positions while RF antennas identify objects with wireless tags, merging two sensing modalities into one integrated system that maintains a thin profile without requiring separate optical components
Solution Approach 2:
The sensing surface achieves multi-functionality by enabling both multi-touch detection and object identification with wireless tags through the same surface area. The capacitive electrodes and RF antennas work together to provide dual functionality without requiring separate dedicated hardware for each function
2Adaptability or versatility
If capacitive and RF sensing are used together, then both touch detection and object identification are improved, but power consumption increases
Solution Approach 1:
The system implements periodic scanning where the RF antenna array alternates between scanning for wireless tags and allowing capacitive sensing to operate. This periodic activation of RF scanning reduces continuous power consumption while maintaining the ability to detect both touch input and identify objects when needed
Solution Approach 2:
The system dynamically switches between capacitive-only mode and combined capacitive-RF mode based on operational needs. The controller activates RF scanning periodically or on-demand rather than continuously, allowing the system to adapt power consumption levels to actual sensing requirements
3Adaptability or versatility
If RF antennas are added to capacitive sensing surface, then object identification is improved, but interference with capacitive sensing occurs
Solution Approach 1:
The sensing surface is segmented into distinct functional zones with capacitive electrodes for touch detection and RF antennas for object identification. This spatial segmentation allows each sensing modality to operate in its designated area, reducing mutual interference while maintaining both functionalities across the overall surface
Solution Approach 2:
The system uses a controller as an intermediary that coordinates between capacitive sensing and RF scanning operations. The controller manages the timing and activation of RF antennas to minimize interference with capacitive touch detection, activating RF scanning only when capacitive sensing is not actively detecting touch input
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
Enables efficient detection and identification of both multi-touch user input and objects with wireless tags, reducing power consumption and increasing operating time between charges for battery-powered devices.
Implementation Method 1
a capacitive sensing electrode array 202... A first sensing module 602 coupled to the capacitive sensing electrode array 202 and configured to detect a change in capacitance
Implementation Method 2
an array of RF antennas 208 with a second sensing module 604 coupled to the array of RF antennas 208... to activate a proximate wireless tag and read data from the tag
Data Source
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AI summary
A multi-modal sensing surface comprises two overlaid arrays: a capacitive sensing electrode array and an array of RF antennas. A first sensing module is coupled to the capacitive sensing electrode array and is configured to detect both an increase and a decrease of capacitance between electrodes in the array. A second sensing module is coupled to the array of RF antennas and is configured to selectively tune and detune one or more of the RF antennas in the array of RF antennas.