OLED Pressure Touch via Hall Effect Magnetic Field Detection

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Solution Overview

Problem

Current pressure touch technologies in OLED display devices, particularly those using electromagnetic induction, struggle to accurately detect pressure levels and distinguish between strong signals from magnetic pens and weak signals from finger touches, limiting their functionality.

Innovation Solution

Integration of magneto-dependent sensors with a silicon-based OLED display device, utilizing the Hall effect to measure pressure by detecting changes in magnetic fields generated by electrified coils or magnetic materials, allowing for precise pressure detection and touch position identification.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If electromagnetic induction pressure sensors with rectangular coils are used, then the device can detect strong signals from magnetic pens, but it cannot accurately distinguish pressure levels or detect weak signals from finger touches

Engineering Contradiction:

Improvepressure detection accuracyVSAvoidsignal detection range

Core Design Contradiction:

Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent changes the fundamental detection parameter from electromagnetic induction to Hall effect measurement. By using Hall elements instead of rectangular coils, the system can detect both strong magnetic pen signals and weak finger touch signals with high precision, resolving the contradiction between measurement precision and adaptability across different signal strengths

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent replaces the electromagnetic induction system (rectangular coils) with a Hall effect-based magnetic field detection system. This substitution enables the sensor to accurately measure pressure levels through vertical magnetic field changes, achieving both high precision and broad adaptability for different touch types

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Device complexity

If rectangular coils are used for pressure sensing, then the structure is simple, but the device cannot perform pressure level distinction with respect to finger pressure

Engineering Contradiction:

Improvesensor structureVSAvoidpressure level detection

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent transitions from electromagnetic induction parameter detection to Hall effect parameter detection. The Hall elements measure vertical magnetic field changes caused by pressure, enabling precise pressure level distinction while maintaining reasonable structural complexity through integration with the display device

Inventive Principle:

Principle #35Parameter changes

3Adaptability or versatility

If electromagnetic induction pressure sensors are integrated into OLED display, then pressure touch function is achieved, but the detection accuracy for different touch types is insufficient

Engineering Contradiction:

Improvetouch functionVSAvoidtouch detection accuracy

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent applies Hall elements at specific locations within the OLED display structure to detect local magnetic field changes. By positioning Hall elements to sense vertical magnetic field variations from both magnetic pens and finger touches, the system achieves high detection accuracy while maintaining adaptability across different touch types

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the detection parameter from electromagnetic induction to Hall effect measurement, enabling the system to accurately distinguish between different touch types (magnetic pen vs. finger touch) based on their respective magnetic field characteristics, thereby improving both adaptability and precision

Inventive Principle:

Principle #35Parameter changes

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 pressure detection accuracy and reduces costs by enabling better pressure touch performance and precise touch position measurement in OLED display devices, improving user interaction and device reliability.

Implementation Method 1

OLEDs use organic compound molecules to emit light through the property of electroluminescence

Methodology Applied

Scientific EffectElectroluminescence: Electroluminescence

Implementation Method 2

the sensor detects a position at which a finger touches or approaches the display device by using a capacitance method

Methodology Applied

Scientific EffectCapacitance: Capacitance

Data Source

PatentEP3489820B1OLED display device and pressure touch-control drive method thereof

Publication Date: 2023.01.25 BOE TECHNOLOGY GROUP CO LTD

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AI summary

An organic light-emitting diode (OLED) display device (400) and a pressure touch driving method, the OLED display device (400) includes: a silicon substrate (302); a pixel unit (300) and a magneto-dependent sensor (100, 305, 401, 501, 601, 701) disposed on one side of the silicon substrate (302); and a magnetic field generator (306) configured to provide magnetic fields running through a plane provided with the magneto-dependent sensor (100, 305, 401, 501, 601, 701) to the magneto-dependent sensor (305); the magneto-dependent sensor (100, 305, 401, 501, 601, 701) is configured to detect magnetic variation and convert the magnetic variation into a voltage difference (Vo+-Vo-) for output.