Capacitive Sensing Unit for Heart Rate Monitoring

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Solution Overview

Problem

Display devices with integrated optical sensors face challenges in power consumption and manufacturing costs due to the need for a light source, which is undesirable for features like heart rate sensing.

Innovation Solution

A sensing unit within the display device that utilizes a base with intersecting electrodes and insulating layers, along with a sensing driving circuit and controller, to sense heart rate without a light source by detecting changes in capacitance, allowing for touch input, pressure, and heart rate monitoring using capacitance changes without the need for a light source.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an optical sensor with a light source is used for heart rate sensing, then sensing functionality is achieved, but power consumption and manufacturing cost increase

Engineering Contradiction:

Improveheart rate sensing functionalityVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent replaces the optical sensing mechanism (which requires a light source) with a capacitive sensing mechanism. The sensing unit uses capacitance changes caused by blood volume pulsations to detect heart rate, eliminating the need for optical components and light sources, thereby reducing power consumption while maintaining heart rate sensing functionality

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent extracts and removes the light source component from the sensing system. By using capacitance-based detection instead of optical detection, the light source is completely eliminated from the device architecture, reducing both power consumption and manufacturing complexity

Inventive Principle:

Principle #2Taking out (Extraction)

2Reliability

If an optical sensor with a light source is used for heart rate sensing, then sensing functionality is achieved, but manufacturing cost increases

Engineering Contradiction:

Improveheart rate sensing functionalityVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces complex optical sensing components with simpler capacitive sensing structures. The sensing unit uses electrode-based capacitance detection, which is easier and less expensive to manufacture compared to optical sensors requiring light sources, filters, and other optical components

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The sensing unit is designed to perform multiple functions using the same capacitive sensing structure. The same electrode configuration used for touch input detection also serves for heart rate sensing by detecting different types of capacitance changes, eliminating the need for separate optical sensing components

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Reliability

If a light source is added to enable optical sensing, then heart rate sensing is possible, but device complexity increases

Engineering Contradiction:

Improveheart rate sensing functionalityVSAvoiddevice complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces the complex optical sensing system with a simpler capacitive sensing system. The sensing unit uses basic electrode structures and capacitance measurement circuits, eliminating the need for light sources, optical filters, and other complex optical components

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The sensing unit utilizes the existing display device structure and electrode system to perform heart rate sensing. By using capacitance changes in the same electrode configuration for both touch and heart rate sensing, the system avoids adding separate optical sensing components, thereby reducing overall device complexity

Inventive Principle:

Principle #25Self-service

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 cost-effective heart rate sensing in display devices by eliminating the requirement for a light source, reducing power consumption and manufacturing costs while maintaining functionality for touch input and pressure detection.

Implementation Method 1

Methodology Applied

Scientific EffectCapacitance: Capacitance

Implementation Method 2

a first insulating layer disposed on the first electrodes, second electrodes arranged on the first insulating layer... a second insulating layer disposed on the second electrodes and the third electrodes

Methodology Applied

Scientific EffectElectrical insulation: Dielectric

Data Source

PatentUS12045424B2Display device, sensing unit, and sensing method

Publication Date: 2024.07.23 SAMSUNG DISPLAY CO LTD

AI summary

A sensing unit includes a base, first electrodes, an insulating layer, second electrodes, and third electrodes. The first electrodes are arranged on the base, extend in a first direction, and are spaced apart from each other in a second direction different from the first direction. The first insulating layer is disposed on the first electrodes. The second electrodes are electrically insulated from the first electrodes by the insulating layer, extend in the second direction, and are spaced apart from each other in the first direction. The third electrodes are electrically insulated from the first electrodes by the insulating layer, extend in the second direction, and are electrically insulated from the second electrodes. The second electrodes and the third electrodes are alternately arranged in the first direction. The third electrodes may receive a driving signal or a sensing signal according to a sensing mode.