Ultrasound Sensor Circuit Rectification for EMI-Resistant Detection
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Solution Overview
Problem
Existing proximity sensor devices face challenges such as geometric distortion, susceptibility to electromagnetic interference (EMI) and electromagnetic discharge (ESD), and limited detection capabilities due to their reliance on capacitive and optical sensing technologies, which restrict their accuracy and versatility in detecting various types of input objects.
Innovation Solution
The implementation of an ultrasound sensor device system that utilizes a circuit with an integrating capacitor and a detection module with sensor electrodes to receive and rectify signals indicative of input objects, providing improved detection capabilities by leveraging the differences in acoustic indices of refraction and being less susceptible to EMI and ESD.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If capacitive sensing is used, then the sensing device has a robust history of use, but it is susceptible to geometric distortion, EMI, ESD, and limited to detecting conductive objects
Solution Approach 1:
The patent replaces capacitive sensing (electrical field-based) with acoustic wave-based sensing. The ultrasound sensor emits acoustic waves that interact with input objects, and the resulting acoustic signals are detected and processed. This substitution enables detection of both conductive and non-conductive objects while eliminating susceptibility to EMI and ESD that plagues capacitive systems.
2Measurement precision
If optical sensing is used, then the sensing device can detect objects, but the accuracy is diminished due to dirt, oils and other contaminants
Solution Approach 1:
The patent substitutes optical sensing with acoustic wave sensing. Acoustic waves propagate through the medium and interact with input objects, with the resulting signals being detected by the ultrasound sensor. This acoustic-based approach is not affected by surface contaminants like dirt and oils that degrade optical sensing accuracy, thereby maintaining consistent detection performance in various environmental conditions.
3Adaptability or versatility
If ultrasound sensing is implemented, then detection versatility improves, but significant challenges remain in development for commercially viable use
Solution Approach 1:
The patent employs self-service principles by integrating the ultrasound sensor, signal processing circuitry, and detection algorithms into a unified system. The sensor device performs its own signal conditioning, noise filtering, and object classification without requiring external complex processing systems, thereby reducing overall system complexity while maintaining detection versatility.
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
The ultrasound sensor system enhances the accuracy and versatility of input detection, allowing for the recognition of both conductive and non-conductive objects, and is less affected by contaminants like dirt and oils, resulting in a more robust and efficient sensing solution.
Implementation Method 1
A subsystem for sensing an input object relative to a sensing region of an ultrasound sensor device includes a circuit, a switch coupled to an output of the circuit, and an integrating capacitor coupled to the output of the circuit. The circuit has an input for receiving a resulting signal comprising positive and negative polarities, the resulting signal having effects indicative of the input object relative to the sensing region.
Implementation Method 2
The array of sensor electrodes are operable to provide resulting signals, each comprising positive and negative polarities in response to presence of the input object in the sensing region.
Implementation Method 3
The detection module is operable to integrate charges onto integrating capacitors of the detection module with rectified signals in response to receiving the resulting signals from the array of sensor electrodes.
Data Source
AI summary
A subsystem, system and method for sensing an input object relative to a sensing region of an ultrasound sensor device are disclosed herein. In one embodiment, a subsystem for sensing an input object relative to a sensing region of an ultrasound sensor device includes a circuit, a switch coupled to an output of the circuit, and an integrating capacitor coupled to the output of the circuit. The circuit has an input for receiving a resulting signal comprising positive and negative polarities, the resulting signal having effects indicative of the input object relative to the sensing region. The integrating capacitor is also coupled to a substantially constant voltage source and to the switch. The circuit is operable to output a rectified signal to the first integrating capacitor indicative of the input object relative to a sensing region.