Touch and Pressure Sensor Layout to Block Capacitive Coupling

Solution Overview

Problem

Existing sensor devices with integrated touch and pressure-sensitive sensors face issues with erroneous detection due to capacitive coupling, which increases the number of components and overall thickness and cost of the device.

Innovation Solution

A sensor device design that incorporates a blocking body integrated with the touch sensor's shield portion, which also functions as an electrode for the pressure-sensitive sensor, thereby eliminating the need for an additional blocking body and reducing the number of components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conductive vapor deposition film (blocking body) is provided independently of the touch panel and pressure sensitive sensor to block capacitive coupling, then erroneous detection of the pressure-sensitive sensor is suppressed, but the number of components increases, total thickness increases, and cost increases

Engineering Contradiction:

Improvedetection accuracyVSAvoidnumber of components

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The blocking body is merged with the shield portion of the touch sensor, forming an integrated structure where the shield portion serves dual functions: shielding the sensor electrode and acting as the blocking body for the pressure-sensitive sensor. This eliminates the need for a separate blocking body component.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The shield portion of the touch sensor is given multiple functions: it serves as the shielding electrode for the touch sensor and simultaneously functions as the blocking body for the pressure-sensitive sensor. This multi-functionality reduces the total number of components required.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If a conductive vapor deposition film (blocking body) is provided independently to block capacitive coupling, then erroneous detection is suppressed, but the total thickness of the product increases

Engineering Contradiction:

Improvedetection accuracyVSAvoidtotal thickness

Core Design Contradiction:

ReliabilityVSLength of stationary object

Solution Approach 1:

The blocking body is merged with the shield portion of the touch sensor, forming an integrated structure where the shield portion serves dual functions: shielding the sensor electrode and acting as the blocking body for the pressure-sensitive sensor. This eliminates the need for a separate blocking body component.

Inventive Principle:

Principle #5Merging (Combining)

3Reliability

If a conductive vapor deposition film (blocking body) is provided independently to block capacitive coupling, then erroneous detection is suppressed, but the cost of the product increases

Engineering Contradiction:

Improvedetection accuracyVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The blocking body is merged with the shield portion of the touch sensor, forming an integrated structure where the shield portion serves dual functions: shielding the sensor electrode and acting as the blocking body for the pressure-sensitive sensor. This eliminates the need for a separate blocking body component.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The shield portion of the touch sensor is given multiple functions: it serves as the shielding electrode for the touch sensor and simultaneously functions as the blocking body for the pressure-sensitive sensor. This multi-functionality reduces the total number of components required.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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

This design effectively suppresses erroneous detection of the pressure-sensitive sensor by blocking capacitive coupling between the operator and the detecting electrode, while also reducing the device's thickness and cost by minimizing the number of components.

Implementation Method 1

the blocking body blocks capacitive coupling between an operator and the detecting electrode caused by approaching of the operator to the operation surface

Methodology Applied

Scientific EffectCapacitive coupling: Capacitance

Implementation Method 2

the blocking body and the detecting electrode constitute a pressure-sensitive sensor that detects a change in capacitance value caused by approaching of the blocking body and the detecting electrode

Methodology Applied

Scientific EffectCapacitance change detection: Capacitance

Data Source

PatentUS12287926B2Sensor device

Publication Date: 2025.04.29 FUJIKURA LTD

AI summary

A sensor device 1A includes: an insulating substrate 11; a touch sensor TS that includes a sensor electrode 12 disposed on a first surface 15a disposed on an operation surface side; a shield electrode 131 disposed on the first surface 15a; and a detecting electrode 14 facing the shield electrode 131 and disposed on a second surface 15b different from the first surface 15a. The first surface 15a is located closer to the operation surface than the second surface 15b, the shield electrode 131 and the detecting electrode 14 constitute a pressure-sensitive sensor that detects a change in capacitance value caused by approaching of the shield electrode 131 and the detecting electrode 14, and the shield electrode 131 blocks capacitive coupling between an operator FIN and the detecting electrode 14 caused by approaching of the operator FIN to the operation surface.