Organic EL Display Power Restriction Circuit

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Solution Overview

Problem

Existing display devices face increasing power consumption and reduced lifetime due to high brightness demands, especially in large panels and sophisticated systems, where attempts to reduce power consumption by lowering screen brightness are insufficient, leading to excessive energy use and shortened organic EL element lifespan.

Innovation Solution

Implement a method to dynamically control the driving voltage and current of organic EL elements by detecting power consumption per display frame, restricting power usage to a fixed value, and adjusting voltage and current based on image brightness to maintain high image quality while limiting power consumption and heat generation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the brightness of the display screen is decreased to reduce power consumption, then the power consumption is reduced, but the image quality and visibility are degraded

Engineering Contradiction:

Improvepower consumptionVSAvoiddisplay brightness

Core Design Contradiction:

Use of energy by moving objectVSIllumination intensity

Solution Approach 1:

The patent implements dynamic control of driving voltage and current based on real-time detection of image signal characteristics. The system adjusts power consumption dynamically rather than using a fixed low brightness setting, allowing optimal power usage while maintaining necessary image quality for different display scenarios

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes physical parameters (driving voltage, driving current, power consumption) based on detected image characteristics. By monitoring image signal properties and adjusting electrical parameters accordingly, the system achieves power reduction without permanent brightness degradation

Inventive Principle:

Principle #35Parameter changes

2Illumination intensity

If the driving voltage and current are increased to maintain high brightness, then the image quality is maintained, but the power consumption increases and the lifetime of organic EL elements decreases

Engineering Contradiction:

Improvedisplay brightnessVSAvoidlifetime of organic EL elements

Core Design Contradiction:

Illumination intensityVSDuration of action of stationary object

Solution Approach 1:

The patent employs a feedback mechanism where the power consumption detection unit continuously monitors power usage and feeds this information back to the power restriction control unit. This closed-loop control adjusts driving voltage and current to maintain brightness while preventing excessive power consumption that would shorten element lifetime

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system performs self-regulation by detecting its own power consumption and automatically adjusting driving parameters. The display device monitors and controls itself to operate within safe power limits, extending element lifetime without external intervention

Inventive Principle:

Principle #25Self-service

3Reliability

If the power consumption is restricted to a fixed value, then the lifetime is prolonged and heat generation is reduced, but the ability to display high brightness images is limited

Engineering Contradiction:

Improvelifetime and reliabilityVSAvoidpeak brightness capability

Core Design Contradiction:

ReliabilityVSIllumination intensity

Solution Approach 1:

The patent applies partial power restriction by setting power limits based on image characteristics rather than uniformly restricting all power consumption. The system allows higher power usage when image content requires it, while restricting power only when unnecessary, achieving a balance between reliability and brightness capability

Inventive Principle:

Principle #16Partial or excessive 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

This approach effectively suppresses power consumption and prolongs the lifetime of organic EL elements by dynamically managing power usage, preventing excessive heat and maintaining high image quality, thus enhancing the reliability and longevity of the display device.

Implementation Method 1

a self-luminous image display device such as a PDP (Plasma Display Panel), a FED (Field Emission Display) or an organic EL (Organic Electro Luminescence) display

Methodology Applied

Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentUS7773080B2Display device and the driving method which restricts electric power

Publication Date: 2010.08.10 SAMSUNG DISPLAY CO LTD

AI summary

A plurality of organic EL elements which are arranged on a display panel lowers the brightness along with a lapse of light emitting time and hence, the power consumption is increased to maintain the brightness. However, the increase of the power consumption shortens a lifetime of the organic EL elements. To overcome this drawback, a power supply circuit which drives the display panel has a function of controlling an electric power supplied to the display panel to a fixed value or less in response to a detection signal from a detection part which detects a cathode current of the organic EL elements.