OLED Demultiplexer Reduces Data Driver IC Count
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Solution Overview
Problem
The increasing number of data lines in active matrix type organic electro-luminescence displays (OLEDs) leads to a rise in the number of costly data driving integrated circuits, processing time, and manufacturing costs, making high-resolution OLED displays more expensive.
Innovation Solution
The implementation of a luminescence display with a data driver having fewer output lines, utilizing a demultiplexer unit to supply data voltages from these output lines to the data lines, and a compensation power line with varying voltage levels to control pixel cells, allowing for efficient current supply to light-emitting elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the number of data lines is increased to achieve high resolution, then the display resolution is improved, but the number of data driving ICs and manufacturing cost increases
Solution Approach 1:
The patent segments the data driving function by introducing a demultiplexer unit that divides the data lines into multiple groups. Each group is driven by a separate data driving IC, allowing the system to handle high resolution displays with fewer ICs by sequentially driving different groups of data lines during different time periods.
Solution Approach 2:
The patent implements periodic action by sequentially driving different groups of data lines in different time periods. The demultiplexer unit switches between groups in a periodic manner, allowing each data driving IC to drive multiple data lines over time, thereby reducing the total number of ICs needed while maintaining high resolution display capability.
2Measurement precision
If the number of data lines is increased to achieve high resolution, then the display resolution is improved, but the manufacturing cost increases
Solution Approach 1:
The patent segments the data driving function by introducing a demultiplexer unit that divides the data lines into multiple groups. Each group is driven by a separate data driving IC, allowing the system to handle high resolution displays with fewer ICs by sequentially driving different groups of data lines during different time periods.
Solution Approach 2:
The patent implements periodic action by sequentially driving different groups of data lines in different time periods. The demultiplexer unit switches between groups in a periodic manner, allowing each data driving IC to drive multiple data lines over time, thereby reducing the total number of ICs needed while maintaining high resolution display capability.
3Ease of operation
If conventional data driving is used, then the display can be operated, but the brightness is uneven and hysteresis occurs
Solution Approach 1:
The patent implements feedback by introducing a compensation power line that provides compensation voltage to the pixel cells. This compensation voltage adjusts for variations in transistor characteristics and aging effects, thereby correcting brightness unevenness and reducing hysteresis. The feedback mechanism ensures that the display maintains uniform brightness and accurate image quality over time.
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 configuration reduces the number of output lines needed, decreases manufacturing costs, and maintains image quality by ensuring even brightness and minimizing hysteresis in the driving transistors, thus addressing the cost and complexity issues associated with high-resolution OLED displays.
Implementation Method 1
each of the pixel cells includes: a light emitting element; and a pixel driver that supplies a current corresponding to a corresponding one of the data voltages to the light emitting element
Data Source
AI summary
A OLED display and a driving method thereof are disclosed. The OLED display includes: an OLED display panel including: data lines to which data voltages are supplied; gate lines to which a gate voltage is sequentially supplied; luminescence control lines to which a luminescence control voltage is sequentially supplied, a driving power line to which a driving voltage is supplied; a compensation power line to which a compensation voltage having a first level and a second level different from the first level are supplied; a plurality of pixel cells each respectively in pixel areas defined by the data lines and the gate lines; a data driver having output lines whose number is smaller than the number of the data lines; and a demultiplexer unit formed between the data driver and the OLED display panel, the demultiplexer unit supplying the data voltages from the output lines to the data lines, wherein each of the pixel cells includes: a light emitting element; and a pixel driver that supplies a current corresponding to a corresponding one of the data voltages to the light emitting element based on the corresponding data voltage, the gate voltage, the luminescence control voltage, the driving voltage and the compensation voltage having the first level and that turns off the light emitting element when the compensation voltage has the second level.