OLED Pixel Circuit Initialization via Data Line Merging
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Solution Overview
Problem
OLED displays require an extra initial power source and line for pixel initialization, complicating the structure and reducing aperture ratio, and leading to non-uniform image quality due to reduced charging time and characteristic deviation compensation.
Innovation Solution
An OLED display design where pixels are initialized by a voltage supplied through a data line, eliminating the need for an extra initial power source and line, using a DeMux driver with data supplying switching elements to sequence data signals and initialize voltage in storage elements, ensuring a lower voltage threshold for uniform image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an extra initial power source and initial line are used to initialize pixels, then pixel initialization can be achieved, but the structure of the pixel circuit becomes complicated and the aperture ratio is reduced
Solution Approach 1:
The patent merges the initialization function into the existing data line structure. The data line serves dual purposes: transmitting data signals during the data writing period and providing initialization voltage during the pixel initializing period. This eliminates the need for a separate initial line and power source, thereby simplifying the pixel circuit structure while maintaining initialization capability.
Solution Approach 2:
The data line is designed to perform multiple functions: it acts as both a data signal transmission line and an initialization voltage supply line. By making the data line universal, the patent removes the requirement for dedicated initialization lines and power sources, reducing overall system complexity without compromising initialization reliability.
2Reliability
If an extra initial power source and initial line are used, then pixel initialization can be achieved, but the aperture ratio of the pixel is reduced
Solution Approach 1:
By combining the initialization function with the existing data line infrastructure, the patent eliminates the need for additional physical lines and power sources that would occupy pixel area. This merging approach preserves the aperture ratio while ensuring reliable pixel initialization through the shared data line.
3Reliability
If the number of data lines is increased to manage initialization, then initialization can be achieved, but there are more integrated circuits required and difficulty in providing high resolution display increases
Solution Approach 1:
The patent makes the data line universal by enabling it to perform both data transmission and initialization functions. This eliminates the need for additional data lines or integrated circuits dedicated to initialization control, thereby maintaining high resolution display capability while reducing overall system complexity.
4Reliability
If previous data signal voltage is higher than current data signal voltage, then the driving switching element may be turned OFF, but the supply of current data signal to the pixel is reduced or prevented
Solution Approach 1:
The patent applies preliminary action by initializing the pixel to a known voltage state before data signal writing. This preliminary initialization ensures that the storage element starts from a defined state, preventing voltage conflicts between previous and current data signals. The initialization voltage is carefully controlled to be lower than the current data signal voltage, ensuring proper switching element operation and complete data signal supply.
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 design simplifies the pixel circuit structure, improves aperture ratio, and enhances image uniformity by allowing longer charging and driving times for data signals, reducing the impact of previous data signals on current data transmission.
Implementation Method 1
An OLED is a type of a flat panel display that uses an OLED to generate light. The light is generated by combining electrons supplied by a cathode and holes supplied by an anode.
Data Source
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AI summary
An OLED display having a plurality of scan lines and a plurality of data lines, an OLED adapted to generate light so as to emit images, a data driver coupled to the plurality of data lines, a driving switching element adapted to supply the OLED with a driving current, a storage element having a first electrode and a second electrode, a first switching element having a first electrode, a control electrode and a second electrode, a second switching element having a control electrode coupled to at least one of the plurality of scan lines and a third switching element having a control electrode coupled to a previous scan line. The second switching element may be configured in a diode-like state connecting the driving switching element. The third switching element may be adapted to initialize a voltage stored in the storage element through at least one of the plurality of data lines.