Capacitive Face-Proximity Detection for Faster Assistant Invocation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing automated assistants require explicit user interface inputs for invocation, which can cause delays and failures due to environmental conditions or user limitations, such as noise or wearing gloves, leading to inefficient interactions.

Innovation Solution

Utilizing capacitive touch sensors to detect non-tactile inputs, like a user holding a device near their face, to implicitly invoke automated assistants, leveraging machine learning models to distinguish between tactile and non-tactile inputs and reduce the need for explicit invocation phrases.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If explicit user interface input is required to invoke automated assistant, then user privacy and resource consumption are controlled, but interaction duration is extended and responsiveness is reduced

Engineering Contradiction:
Improveprivacy controlVSAvoidinteraction duration
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The system performs preliminary detection of facial features near the display using capacitive sensors before the user actually intends to interact. By detecting the presence of facial features (mouth, nose, eyes) in proximity to the display area, the system prepares for potential interaction in advance, reducing the time required when the user actually wants to invoke the assistant.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system dynamically adjusts the invocation mechanism based on real-time detection. When facial features are detected near the display, the system transitions from requiring explicit invocation (static state) to enabling implicit invocation through facial gestures (dynamic state). This dynamic adaptation allows the system to optimize between privacy control and responsiveness based on current context.

Inventive Principle:
Principle #15Dynamics

2Reliability

If explicit user interface input is required to invoke automated assistant, then false positive invocations are reduced, but invocation reliability fails in noisy environments or when user dexterity is limited

Engineering Contradiction:
Improveinvocation accuracyVSAvoidenvironmental adaptability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The capacitive touch sensor array serves as an intermediary between the user and the automated assistant invocation. Instead of directly detecting voice commands (which fail in noisy environments) or touch inputs (which fail when wearing gloves), the system uses capacitive sensors to detect facial features near the display as an intermediate signal that reliably indicates invocation intent across various environmental conditions.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system changes the detection parameter from acoustic (voice recognition) or tactile (touch input) to capacitive (electrical field detection near the display). This parameter change allows the system to detect facial features through the display surface without requiring direct contact or clear audio, thereby maintaining invocation reliability across diverse environmental conditions including noise, gloves, and face masks.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If capacitive touch sensors are used for both tactile and non-tactile input detection, then invocation versatility is improved, but input detection precision may be compromised

Engineering Contradiction:
Improveinput method versatilityVSAvoidinput detection accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The system segments the capacitive sensor array into different functional zones: tactile input areas for direct touch interaction and facial detection areas for non-tactile facial feature detection. By spatially segmenting the sensor array and applying different detection algorithms to different zones, the system maintains high precision for both tactile and non-tactile input modes simultaneously.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system applies different detection characteristics to different regions of the capacitive sensor array. Facial feature detection is performed with specific sensitivity thresholds and pattern recognition algorithms optimized for facial geometries, while tactile input detection uses different thresholds for direct contact. This local quality differentiation ensures that each input mode maintains high detection precision despite using the same underlying sensor technology.

Inventive Principle:
Principle #3Local quality

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 and reliable invocation of automated assistants without explicit user input, reducing interaction delays and improving responsiveness in various environments.

Implementation Method 1

The touch display interface can include an array of capacitive touch sensors that can operate by being responsive to static charge and/or changes in charge of nearby surfaces.

Methodology Applied
Scientific EffectCapacitance: Capacitance

Implementation Method 2

capacitive touch sensors that can operate by being responsive to static charge and/or changes in charge of nearby surfaces

Methodology Applied
Scientific EffectElectrostatic Induction: Electrostatic Induction

Data Source

PatentUS20250377919A1Selectively invoking an automated assistant according to a result of shape detection at a capacitive array
Publication Date: 2025.12.11 GOOGLE LLC
  • US20250377919A1 patent drawing
  • US20250377919A1 patent drawing
  • US20250377919A1 patent drawing

AI summary

Implementations set forth herein relate to controlling invocation of an automated assistant according to whether a capacitive touch sensor array has detected a particular input that indicates a user has positioned an assistant-enabled device near their face. The capacitive touch sensor array can be part of a touch display interface of a portable computing device that provides access to an automated assistant. When the interface is positioned near the face of the user, input data from the interface can be processed to determine whether the input data indicates the display interface is near their face or whether the user is providing some other input to the display interface. When the input data indicates the user is positioning the display interface near their face or mouth, the automated assistant can be invoked in lieu of the user providing any other invocation input.