Sensor Driver Interference Mitigation for Display Proximity

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Solution Overview

Problem

Proximity sensor devices in electronic systems face interference from external sources, such as display devices, which affects the accuracy of input object detection, making it difficult to reliably detect inputs like fingers or styluses.

Innovation Solution

Incorporating an interference mitigation element within the sensor driver that receives interference data and uses a transfer function to generate an interference estimate, which is then communicated to the receiver to mitigate the effects of interference in the resulting signals from sensor electrodes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If proximity sensor devices are used in electronic systems with display devices, then the input device can provide user interface functionality, but the sensor signals are affected by display interference which reduces detection accuracy

Engineering Contradiction:

Improveinput device functionalityVSAvoidinput object detection accuracy

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent introduces an intermediary signal processing path that includes interference estimation circuitry and transfer function application. This intermediary processing chain separates the interference mitigation function from the main sensing path, allowing the sensor to continue operating while a parallel process estimates and removes display interference from the resulting signals, thereby preserving both functionality and measurement precision

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If the sensor operates in the presence of display interference, then the device can be used with display systems, but the resulting signals contain interference that degrades signal quality

Engineering Contradiction:

Improvecompatibility with display systemsVSAvoiddisplay interference in sensor signals

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent converts the harmful display interference into a beneficial signal by using the known display drive signals as input to a transfer function. The interference that would normally degrade signal quality is instead modeled and predicted, then subtracted from the sensor output. This transforms the harmful electromagnetic interference from the display into useful information for cancellation, improving signal quality while maintaining compatibility with display systems

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Data Source

PatentUS11294505B2Display interference mitigation

Publication Date: 2022.04.05 SYNAPTICS INC

AI summary

A sensor driver comprises a receiver and an interference mitigation element. The receiver is configured to acquire a resulting signal from a sensor electrode. The interference mitigation element is communicatively coupled with the receiver and is configured to receive interference data, generate an interference estimate from the interference data and a transfer function, and communicate the interference estimate to the receiver. The interference estimate removes charge from a resulting signal, mitigating effects of interference within the resulting signal.