Integrated Display Force Sensing via Capacitive Electrode Deflection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current capacitive sensing technologies in integrated display devices lack the ability to effectively detect force information from input objects, as they primarily focus on proximity and motion detection without incorporating force sensing capabilities.

Innovation Solution

The integration of a processing system with sensor electrodes that can detect changes in absolute capacitance, allowing for the determination of force information by deflecting sensor electrodes towards a conductive electrode, enabling force sensing in addition to capacitive sensing and display updating.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional capacitive sensing technologies are used in integrated display devices, then proximity and motion detection can be achieved, but force information detection capability is lost

Engineering Contradiction:

Improveforce information detectionVSAvoidsensing capability

Core Design Contradiction:

Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent merges force sensing capability with existing capacitive sensing technology by integrating force-sensitive electrodes into the display structure. The electrodes serve dual purposes: traditional capacitive sensing for touch detection and force sensing for pressure measurement, combining multiple sensing functions into a single integrated system.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The sensor electrodes are designed to perform multiple functions simultaneously: display updating, capacitive sensing for touch detection, and force sensing for pressure measurement. This multi-functional design allows the same hardware infrastructure to support diverse sensing capabilities without requiring separate dedicated components.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Measurement precision

If sensor electrodes are configured to deflect toward conductive electrode for force sensing, then force information can be detected, but device structure becomes more complex

Engineering Contradiction:

Improveforce sensing accuracyVSAvoidelectrode configuration

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent employs flexible sensor electrodes that can deflect toward the conductive electrode when force is applied. This flexibility enables force sensing through capacitance changes while maintaining a relatively simple layered structure, avoiding the need for complex mechanical force-sensing components.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The patent replaces traditional mechanical force sensing mechanisms with an electrical field-based capacitive sensing system. Instead of using mechanical springs, levers, or strain gauges, the system uses deflection of flexible electrodes and measurement of capacitance changes to detect force, simplifying the mechanical complexity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If processing system detects changes in absolute capacitance for force sensing, then force information and positional data can be obtained, but energy consumption increases

Engineering Contradiction:

Improveinput recognition accuracyVSAvoidprocessing energy

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent implements continuous capacitive sensing and display updating using the same electrode infrastructure. By maintaining continuous electrical fields and using the same electrodes for both display and sensing functions, the system achieves comprehensive input recognition without requiring separate dedicated force-sensing hardware that would consume additional energy.

Inventive Principle:

Principle #20Continuity of useful action

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 the detection of force information in conjunction with positional data, enhancing the input device's capability to recognize inputs and gestures by measuring changes in absolute capacitance caused by applied forces.

Implementation Method 1

detect changes in absolute capacitance of at least a portion of the plurality of sensor electrodes

Methodology Applied

Scientific EffectCapacitance: Capacitance

Implementation Method 2

the plurality of sensor electrodes are configured to deflect toward the conductive electrode

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS9733756B2Integrated display device and sensing device with force sensing

Publication Date: 2017.08.15 SYNAPTICS INC

AI summary

An example integrated display device and capacitive sensing device having an input surface includes a plurality of sensor electrodes. Each of the plurality of sensor electrodes includes at least one common electrode configured for display updating and capacitive sensing. The device further includes at least one conductive electrode, wherein the plurality of sensor electrodes are disposed between the input surface and the at least one conductive electrode and wherein the plurality of sensor electrodes are configured to deflect toward the conductive electrode. The device further includes a processing system, coupled to the plurality of sensor electrodes, configured to detect changes in absolute capacitance of at least a portion of the plurality of sensor electrodes, and determine force information for an input object based on the changes in absolute capacitance.