OLED Pixel Initialization Without Dedicated Power Line
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Solution Overview
Problem
Existing organic light emitting display devices require an initialization power and initialization power line to initialize pixels, which can lead to spatial limitations in pixel layout.
Innovation Solution
A pixel design for organic light emitting display devices that initializes the driving transistor without an initialization power or initialization power line, using an initialization block with a diode, capacitors, and transistors to control voltage levels and store data signals, allowing for simplified pixel layout.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an initialization power and initialization power line are used to initialize pixels, then the pixel can be properly initialized, but spatial limitations occur in the pixel layout
Solution Approach 1:
The invention extracts and eliminates the initialization power line from the pixel structure by using the existing emission power line to provide both emission voltage and initialization voltage at different time periods. This removes the separate initialization power line that was causing spatial limitations in the pixel layout.
Solution Approach 2:
The emission power line is given dual functionality: it serves as both the emission power line during the emission period and as the initialization power line during the initialization period. This multi-functionality eliminates the need for a separate initialization power line, thereby improving pixel layout flexibility.
2Reliability
If an initialization power line is added to provide initialization voltage, then pixel initialization is enabled, but the device complexity increases
Solution Approach 1:
The invention merges the initialization power line function with the existing emission power line. By combining these two functions into a single power line, the device complexity is reduced while maintaining the necessary pixel initialization capability.
Solution Approach 2:
The emission power line performs multiple functions by providing both emission voltage and initialization voltage at different time periods, eliminating the need for separate dedicated initialization power infrastructure and thereby reducing device complexity.
3Reliability
If separate initialization and emission power lines are used, then reliable voltage control is achieved, but the pixel layout becomes more complex
Solution Approach 1:
The power line operates in periodic cycles, providing initialization voltage during initialization periods and emission voltage during emission periods. This time-division multiplexing approach maintains reliable voltage control while using a single power line configuration.
Solution Approach 2:
The power line's function dynamically changes over time, transitioning between initialization and emission modes. This dynamic operation allows a single power line to replace what would traditionally require two separate static power lines, simplifying the overall configuration.
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
Enables the initialization of pixels without the need for an initialization power or power line, simplifying the pixel layout and improving the design efficiency of organic light emitting display devices.
Implementation Method 1
a storage capacitor coupled between the first node and a high-power voltage line, the storage capacitor being configured to store a data signal provided through the first transistor
Implementation Method 2
a diode including an anode electrode coupled to the first node, and a cathode electrode coupled to a fourth node
Implementation Method 3
an organic light emitting diode
Data Source
AI summary
A pixel of an organic light emitting display device includes an organic light emitting diode, a driving transistor including a gate electrode coupled to a first node, a first electrode coupled to a second node, and a second electrode coupled to a third node, the driving transistor being configured to control a driving current through the organic light emitting diode based on a voltage of the first node, a first transistor coupled between the second node and a data line, the first transistor being configured to be turned on in response to a scan signal provided through a current scan line, a storage capacitor coupled between the first node and a high-power voltage line, the storage capacitor being configured to store a data signal provided through the first transistor, and an initialization block configured to initialize the first node based on a scan signal provided through a previous scan line.