Series LED Circuit Layout for Lower TFT Drive Stress

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Solution Overview

Problem

Existing light-emitting diode (LED) systems face challenges in maximizing power efficiency and prolonging the lifespan of thin-film transistors due to high power consumption and heat generation, particularly when using small-sized LEDs as current driving components.

Innovation Solution

The electronic device design couples multiple light-emitting diodes in series, with a circuit unit including thin-film transistors and a capacitor to manage power distribution, reducing the driving current and voltage drop across each diode, thereby increasing power efficiency and extending the lifespan of switch components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If multiple light-emitting diodes are coupled in series, then power conversion efficiency is improved and proportion of power consumption by light-emitting unit is increased, but device complexity increases

Engineering Contradiction:
Improvepower conversion efficiencyVSAvoidcircuit configuration complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The light-emitting unit is segmented into multiple diodes (first diode and second diode) coupled in series, allowing each diode to operate at optimized current levels while collectively achieving higher power efficiency and greater proportion of total power consumption by the light-emitting unit

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from single-diode configuration to multi-diode series configuration, adding a dimensional aspect to the circuit architecture that enables improved power conversion efficiency through distributed voltage and current management across multiple components

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Volume of moving object

If small-sized LEDs are used as current driving components, then device size is reduced, but power consumption increases and heat generation increases

Engineering Contradiction:
ImproveLED sizeVSAvoidpower consumption
Core Design Contradiction:
Volume of moving objectVSUse of energy by moving object

Solution Approach 1:

The small-sized LED system is segmented into multiple diodes in series, where each diode operates at lower current levels, reducing overall power consumption and heat generation while maintaining the compact form factor

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the electrical parameters by distributing the voltage and current across multiple diodes, transforming the operating conditions from high current single-diode mode to lower current multi-diode series mode, thereby reducing power consumption and thermal output

Inventive Principle:
Principle #35Parameter changes

3Power

If high drive current is used for small-sized LEDs, then sufficient driving power is achieved, but thin-film transistor lifespan is reduced

Engineering Contradiction:
Improvedriving powerVSAvoidthin-film transistor lifespan
Core Design Contradiction:
PowerVSDuration of action of stationary object

Solution Approach 1:

The driving power is segmented across multiple diodes in series, reducing the current burden on each diode and consequently reducing the stress on the thin-film transistor, thereby extending its operational lifespan while maintaining sufficient total driving power

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The multi-diode series configuration acts as an intermediary between the power source and the light-emitting unit, distributing and regulating the current flow to protect the thin-film transistor from excessive current stress while ensuring adequate driving power is delivered

Inventive Principle:
Principle #24Intermediary (Mediator)

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 configuration enhances power conversion efficiency, increases the proportion of power consumption by the light-emitting unit, and prolongs the lifetime of thin-film transistors by reducing the load on the driving unit, while also achieving higher brightness due to the smaller size and longer edge length of the coupled LEDs.

Implementation Method 1

At least one of the first diode and the second diode is a light-emitting diode

Methodology Applied
Scientific EffectLight-emitting diode effect: Light Emitting Diode

Implementation Method 2

a first diode and a second diode coupled in series. At least one of the first diode and the second diode is a light-emitting diode

Methodology Applied
Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentEP3499592B1Electronic device
Publication Date: 2024.07.03 INNOLUX CORP
  • EP3499592B1 patent drawingFigure 1
  • EP3499592B1 patent drawingFigure 2~3
  • EP3499592B1 patent drawingFigure 4~5

AI summary

The present disclosure provides an electronic device (DAI, DA2, LD1, LD2, LD3, LD4, LD5, LD6) including a light-emitting unit (LU, LU1, LU2, LU3, LU4) and at least one circuit unit (CU1, CU2, CU5, CU6). The light-emitting unit (LU, LU1, LU2, LU3, LU4) includes at least two diodes (DC) coupled in series. At least one of the diodes (DC) is a light-emitting diode for generating light. The circuit unit (CU1, CU2, CU5, CU6) includes a thin-film transistor (TFT1) or switch component coupled to a first end (T1, T2) of the light-emitting unit (LU, LU1, LU2, LU3, LU4) and a power source (HP, LP).