OLED Power Source Voltage Control for Brightness
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Solution Overview
Problem
Organic light emitting displays face inefficiencies in power management, leading to increased net power consumption and reduced panel life due to unnecessary power usage by the driving transistor, especially when displaying low gray levels, which also limits the voltage of the first power source and affects brightness.
Innovation Solution
An organic light emitting display system that includes a first power source controller and generator, which extracts the highest gray level data from input frames to determine and generate a voltage for the first power source, using a DC-DC converter and digital resistance to control current flow, thereby reducing net power consumption and optimizing voltage for each color component.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a fixed high voltage is supplied to the first power source to ensure sufficient brightness, then the brightness is maintained, but the net power consumption increases and panel temperature rises
Solution Approach 1:
The patent applies dynamics by making the first power source voltage variable rather than fixed. The voltage is dynamically adjusted based on the maximum gray level data extracted from the current frame, allowing the system to adapt the power supply to actual display requirements, thereby reducing unnecessary power consumption while maintaining sufficient brightness.
Solution Approach 2:
The patent changes the voltage parameter of the first power source based on the maximum gray level value extracted from input data. By mapping gray level values to corresponding voltage levels, the system optimizes power consumption by supplying only the necessary voltage required for the current display content, rather than maintaining a constantly high voltage.
2Power
If a fixed high voltage is supplied to the first power source, then sufficient current is available for OLED operation, but the driving transistor consumes unnecessary power reducing panel life
Solution Approach 1:
The system dynamically adjusts the first power source voltage based on the maximum gray level data, ensuring that the driving transistor operates only with the necessary voltage and current levels. This reduces unnecessary power dissipation in the driving transistor, lowering heat generation and extending panel operational life.
3Loss of energy
If the first power source voltage is reduced to lower power consumption, then net power decreases, but the voltage becomes insufficient for proper OLED operation
Solution Approach 1:
The patent implements parameter changes by establishing a correspondence between gray level values and voltage levels. The first power source voltage is set according to the maximum gray level value extracted from the current frame data, ensuring that the voltage is neither excessively high nor insufficient, but precisely matched to the display requirements.
4Illumination intensity
If separate power sources are used for scan and emission periods, then peak brightness is improved, but the device complexity increases
Solution Approach 1:
The patent applies periodic action by supplying different voltage levels for scan period and emission period. During the scan period, a first voltage level is supplied, and during the emission period, a second voltage level is supplied. This temporal separation allows optimization of brightness during emission while managing power consumption during scanning, without requiring physically separate power sources.
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 reduces net power consumption, lowers panel temperature, and extends OLED life by dynamically controlling the voltage based on gray level data, while allowing for improved peak brightness through distinct power sourcing in scan and emission periods.
Implementation Method 1
a DC-DC converter for generating the first power source
Implementation Method 2
organic light emitting diodes (OLED) that generate light by re-combination of electrons and holes
Implementation Method 3
a digital resistance for feeding back the voltage of the first power source to the DC-DC converter
Data Source
AI summary
The organic light emitting display may include a plurality of pixels for generating light components with predetermined brightness components while controlling the amount of current that flows from a first power source to a second power source via organic light emitting diodes (OLED), a first power source controller for extracting data of the highest gray level among input data items of one frame and for outputting a control value having voltage information corresponding to the highest gray level data, and a first power source generator for generating a controlled voltage value corresponding to the control value and outputting the controlled voltage value to the first power source.