Adaptive Black Gray Scale Voltage Control for OLED Displays

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Solution Overview

Problem

Display devices exhibit luminance variations due to material properties and environmental changes, leading to increased power consumption and issues like afterimages and color shifts, especially in low-luminance or low-gray scale displays, as conventional methods provide large voltage margins to address these variations.

Innovation Solution

A driving voltage setting device that determines black gray scale voltages for OLED display devices by measuring luminance and adjusting voltages to specific conditions, using a first and second voltage determiner to set optimal voltages for maximum and minimum luminance, and interpolates between these to calculate voltages for intermediate luminances, thereby reducing unnecessary power consumption and display defects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a large margin value is provided to set voltage values to address luminance variations, then luminance consistency is improved, but power consumption increases

Engineering Contradiction:
Improveluminance consistencyVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies dynamics by making the black gray scale voltage adaptive rather than fixed. The system automatically adjusts the black gray scale voltage based on measured luminance characteristics of individual display devices, allowing the voltage to dynamically adapt to each device's specific properties. This eliminates the need for large fixed margins while maintaining luminance consistency across devices.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of black gray scale voltage from a fixed conservative value to a dynamically adjusted value based on measured luminance. By measuring the actual luminance output and calculating an optimized voltage value, the system transforms the voltage parameter to achieve both luminance consistency and reduced power consumption.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If a large margin value is provided to set voltage values to address luminance variations, then luminance consistency is improved, but display quality deteriorates due to afterimages and color shifts

Engineering Contradiction:
Improveluminance consistencyVSAvoidafterimages and color shifts
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The system dynamically adjusts the black gray scale voltage based on measured luminance characteristics, allowing the voltage to adapt to each display device's specific properties. This dynamic adjustment prevents the use of excessively large voltage margins that cause afterimages and color shifts, while still ensuring luminance consistency across devices.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements feedback by measuring the luminance output of individual display devices and using this measurement to calculate an optimized black gray scale voltage. This closed-loop feedback mechanism ensures that the voltage is precisely tuned to each device's characteristics, preventing both luminance inconsistency and display defects like afterimages.

Inventive Principle:
Principle #23Feedback

3Productivity

If individual display devices are separated by scribing the mother substrate to reduce manufacturing cost, then manufacturing efficiency is improved, but luminance variations increase due to material properties and environmental changes

Engineering Contradiction:
Improvemanufacturing efficiencyVSAvoidluminance consistency
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies local quality by measuring and adjusting the black gray scale voltage for each individual display device based on its specific luminance characteristics. Instead of applying a uniform voltage setting to all devices, the system tailors the voltage to each device's local properties, compensating for variations caused by material properties and environmental changes.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system changes the voltage parameter individually for each display device based on measured luminance characteristics. By measuring the actual luminance output of each separated device and calculating an optimized voltage value, the system compensates for variations introduced during the scribing process and ensures consistent luminance across all devices.

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

The solution effectively minimizes power consumption and reduces afterimages and color shifts by adaptively changing black gray scale voltages based on display luminance, ensuring stable and efficient operation across various luminance conditions.

Implementation Method 1

a luminance measurer to measure a luminance of a black gray scale of the display device

Methodology Applied
Scientific EffectLuminance measurement:

Data Source

PatentEP3564938B1Driving voltage setting device and method of setting driving voltage for display device
Publication Date: 2023.11.01 SAMSUNG DISPLAY CO LTD
  • EP3564938B1 patent drawingFigure 1
  • EP3564938B1 patent drawingFigure 2
  • EP3564938B1 patent drawingFigure 3

AI summary

A driving voltage setting device includes a first voltage determiner, a luminance measurer, and a second voltage determiner. The first voltage determiner is configured to: determine, based on a variable preliminary black gray scale voltage (BGSV) under a first display luminance condition, a first BGSV corresponding to a first display luminance of a display device; and determine, based on the variable preliminary BGSV under a second display luminance condition, a second BGSV corresponding to a second display luminance of the display device. The luminance measurer is configured to measure a luminance of a BGSV of the display device using the variable preliminary BGSV. The second voltage determiner is configured to determine, based on the first BGSV and the second BGSV, BGSVs respectively corresponding to a plurality of preset display luminances between the first display luminance and the second display luminance.