Earphone Capacitive Sensing Layout for Low-Interference In-Ear Detection

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Solution Overview

Problem

Traditional capacitance sensing solutions for in-ear detection in earphones are prone to interference and require assembly of the whole device for functional testing, leading to low production efficiency and yield.

Innovation Solution

Integration of the sensing electrode and processing unit on the front housing of the earphone with a short metal wiring layer connection, allowing for miniaturization and improved anti-interference performance, enabling testing during the semi-manufactured stage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the sensing electrode and processing unit are arranged in separate locations (front housing and rear housing), then the capacitance detection signal can be transmitted over a longer distance, but the anti-interference performance deteriorates and the device occupies more space

Engineering Contradiction:
Improveanti-interference performanceVSAvoidspace occupied by capacitance detection apparatus
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The sensing electrode and processing unit are integrated into a single capacitance detection apparatus located at the front housing of the earphone. This merging eliminates the need for long analog signal transmission lines, significantly reducing interference and improving detection reliability while compacting the overall device volume.

Inventive Principle:
Principle #5Merging (Combining)

2Measurement precision

If the sensing electrode and processing unit are integrated at the front housing, then the anti-interference performance and miniaturization are improved, but the complexity of assembling and testing increases

Engineering Contradiction:
Improvecapacitance detection performanceVSAvoidassembly and testing process
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The capacitance detection apparatus is designed as a separate integrated module that can be assembled independently before being installed into the earphone. This segmentation allows for pre-testing of the capacitance detection function at the module level, simplifying the overall manufacturing process by enabling early functional verification without requiring complete earphone assembly.

Inventive Principle:
Principle #1Segmentation

3Productivity

If functional testing is performed after complete earphone assembly, then all components are available for testing, but production efficiency and yield improvement are limited

Engineering Contradiction:
Improveproduction efficiency and yieldVSAvoidtesting time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The capacitance detection apparatus is designed to enable preliminary functional testing during the semi-manufactured state of the earphone, before complete assembly. This allows detection functions to be verified early in the production process, enabling timely identification and correction of defects, thereby improving overall production efficiency and yield without requiring additional testing time after assembly.

Inventive Principle:
Principle #10Preliminary 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

Enhances capacitance detection performance, improves production efficiency, and increases yield by reducing interference and allowing for earlier functional testing.

Implementation Method 1

the sensing electrode is configured to sense a to-be-measured object and form a capacitance detection signal

Methodology Applied
Scientific EffectCapacitance: Capacitance

Data Source

PatentEP4087273A1Capacitance measurement apparatus and earphone
Publication Date: 2022.11.09 SHENZHEN GOODIX TECH CO LTD
  • EP4087273A1 patent drawingFigure 1~2
  • EP4087273A1 patent drawingFigure 3~5
  • EP4087273A1 patent drawingFigure 6~7

AI summary

A capacitance detection apparatus and earphone can improve the detection performance of the capacitance detection apparatus and improve the production efficiency and yield of the earphone. The capacitance detection apparatus is applied to an earphone and the earphone includes a front housing and a rear housing, where the capacitance detection apparatus includes: a circuit board, a sensing electrode and a processing unit which are provided at the front housing of the earphone, where the circuit board, the sensing electrode and the processing unit are integrated together; the sensing electrode is arranged in a first area of the circuit board, the processing unit is arranged in a second area of the circuit board, and the sensing electrode and the processing unit are electrically connected through a metal wiring layer in the circuit board; the sensing electrode is configured to sense a to-be-measured object and form a capacitance detection signal, the capacitance detection signal is transmitted to the processing unit through the metal wiring layer, and the processing unit is configured to process the capacitance detection signal to detect the to-be-measured object. Based on this, respective parts of the capacitance detection apparatus are integrally arranged, and thus it can be miniaturized and have good anti-interference performance, and tests on functions can be performed when the earphone is in a semi-finished state.