Organic EL Display Brightness Stability via Dynamic Voltage Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional organic EL display devices face high power consumption due to large voltage differences required for temperature correction, which affects brightness stability across environmental temperature changes and secular deterioration of organic EL elements.
Innovation Solution
The display device incorporates a detection unit with a monitor element and constant current sources to reduce voltage variation ranges, using changeover switches and analog circuits to control current sources, allowing the system to operate with lower power consumption by adjusting current values based on detected voltage values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If conventional temperature correction systems use large voltage ranges to compensate for environmental temperature changes, then brightness stability is improved, but power consumption increases
Solution Approach 1:
The patent dynamically adjusts the voltage applied to the monitor element based on detected environmental temperature, using multiple current sources with different voltage levels. This dynamic adaptation allows the system to maintain brightness stability while minimizing power consumption by selecting appropriate voltage levels rather than continuously operating at high voltage ranges.
Solution Approach 2:
The system changes operating parameters (voltage levels) of the monitor element according to environmental temperature conditions. By implementing temperature-dependent voltage adjustment with discrete voltage levels, the patent achieves brightness compensation while reducing overall power consumption compared to conventional systems that maintain large voltage ranges.
2Use of energy by moving object
If the voltage range for monitor element operation is reduced to lower power consumption, then power efficiency is improved, but temperature correction capability deteriorates
Solution Approach 1:
The patent segments the voltage range into multiple discrete levels using separate current sources, each optimized for specific temperature ranges. This segmentation allows the system to use only the necessary voltage level for current temperature conditions, reducing overall power consumption while maintaining adequate temperature correction capability through selective voltage application.
Solution Approach 2:
The system dynamically selects appropriate voltage levels based on real-time temperature detection, adapting the voltage range to actual environmental conditions. This dynamic adjustment ensures temperature correction capability is maintained when needed while minimizing power consumption during operation.
3Use of energy by moving object
If multiple current sources with different voltage levels are used to reduce voltage variation ranges, then power consumption is reduced, but device complexity increases
Solution Approach 1:
The patent combines multiple current sources with different voltage levels into a unified monitor element control system, sharing common detection circuits and control logic. This merging approach reduces overall circuit complexity compared to implementing separate correction systems, while still achieving power consumption reduction through selective voltage usage.
Solution Approach 2:
The detection unit and control circuitry serve multiple functions: detecting environmental temperature, determining appropriate voltage levels, and controlling the selection of current sources. This multi-functionality reduces the need for separate dedicated circuits, thereby managing device complexity while enabling power consumption optimization.
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 enables the display device to maintain brightness stability with reduced power consumption by minimizing voltage ranges, effectively addressing variations in environmental temperatures and secular changes in organic EL elements.
Implementation Method 1
A spontaneous light emitting display device that configures pixels with light emitting elements such as organic EL elements
Implementation Method 2
an organic EL element is used for the monitor element 20... the voltage of the anode of the organic EL device being the monitor element 20 is set to a voltage V1 as a high temperature region when an environmental temperature is a defined temperature abnormality, and set to a voltage V1′ in the case of low temperatures lower than it
Data Source
AI summary
To implement brightness change of pixels due to variations in environmental temperatures with low electric power, the display device includes a display part having a display area arrayed with plural pixels, a display scanning circuit and a signal driving circuit for driving the plural pixels, and a power circuit that supplies a current for illuminating each of the plural pixels with brightness corresponding to a display signal from the signal driving circuit; and a detection unit that includes: a monitor element for driving a constant current that detects environmental temperatures; and plural constant current sources, detects a voltage value relating to the luminous intensity of the pixels by the monitor element to generate a signal to control an output voltage of the power circuit, and changes over a constant current source of the monitor element according to a voltage value detected in the detection unit.