OLED Display Voltage Regulation via Luminance Feedback

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Solution Overview

Problem

Conventional organic electroluminescence (EL) display devices face high power consumption due to voltage drop in power source wires, especially in larger displays, leading to inefficient energy use and heat generation, which affects the longevity of the organic EL elements.

Innovation Solution

A display device with a power supplying unit that outputs high-side and low-side potentials, a detecting line to monitor voltage drops, and a voltage regulating unit to adjust these potentials, reducing unnecessary power consumption by detecting voltage drops and compensating for them, thereby minimizing energy waste.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the power supply voltage is set with a voltage drop margin to compensate for wire resistance, then display uniformity is improved, but power consumption increases

Engineering Contradiction:
Improvedisplay uniformityVSAvoidpower consumption
Core Design Contradiction:
Stability of the object's compositionVSUse of energy by moving object

Solution Approach 1:

The patent applies dynamics by making the power supply voltage adjustable rather than fixed. The voltage is dynamically changed based on detected pixel luminance values - higher voltage is applied only when and where needed to compensate for voltage drops in high-brightness regions, while lower voltage is used in other regions and times, thereby maintaining display uniformity while reducing overall power consumption

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the voltage parameter dynamically based on detected luminance conditions. By monitoring pixel luminance and adjusting the power supply voltage accordingly, the system optimizes the balance between compensation for wire resistance (display uniformity) and energy consumption, applying voltage drop margin only when necessary rather than continuously

Inventive Principle:
Principle #35Parameter changes

2Area of stationary object

If the display size is enlarged, then display area is improved, but voltage drop in power source wires increases

Engineering Contradiction:
Improvedisplay areaVSAvoidvoltage drop
Core Design Contradiction:
Area of stationary objectVSLoss of energy

Solution Approach 1:

The patent implements feedback by detecting the luminance values of pixels and using this information to adjust the power supply voltage. The detection unit monitors pixel luminance, and based on this feedback, the system determines the appropriate voltage level to apply, thereby compensating for voltage drops in large displays without unnecessarily increasing power consumption across the entire display area

Inventive Principle:
Principle #23Feedback

3Stability of the object's composition

If the power supply voltage is increased to compensate for voltage drop, then pixel luminance uniformity is improved, but heat generation increases

Engineering Contradiction:
Improveluminance uniformityVSAvoidheat generation
Core Design Contradiction:
Stability of the object's compositionVSTemperature

Solution Approach 1:

The patent applies dynamics by making the power supply voltage adjustable rather than fixed. The voltage is dynamically changed based on detected pixel luminance values - higher voltage is applied only when and where needed to compensate for voltage drops in high-brightness regions, while lower voltage is used in other regions and times, thereby maintaining display uniformity while reducing overall power consumption

Inventive Principle:
Principle #15Dynamics

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

The solution effectively reduces power consumption and heat generation, enhancing the longevity of organic EL elements and maintaining display quality by optimizing voltage distribution across the display device.

Implementation Method 1

active-matrix display devices which use current-driven luminescence elements represented by organic electroluminescence (EL) elements

Methodology Applied
Scientific EffectElectroluminescence: Electroluminescence

Implementation Method 2

current flows through a power source wire and a voltage drop which is proportionate to the wire resistance occurs

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP2733691B1Display device
Publication Date: 2017.09.20 JOLED INC
  • EP2733691B1 patent drawingFigure 1
  • EP2733691B1 patent drawingFigure 2
  • EP2733691B1 patent drawingFigure 3

AI summary

A display device in the present invention includes: a power supplying unit which outputs at least one of a high-side output potential and a low-side output potential; a display unit in which pixels (111) are arranged in a matrix and which receives power supply from the power supplying unit; a monitor wire (10A) arranged along a column direction of the pixels (111) in the matrix, which has one end connected to at least one pixel (111M) inside the display unit, and is for transmitting the high-side potential to be applied to the pixel (111M); and a voltage regulating unit connected to the other end of the monitor wire (10A), which regulates at least one of the high-side output potential and the low-side output potential to be outputted by the power supplying unit, to set a potential difference between the high-side potential and the low-side potential to a predetermined potential difference.