OLED Pixel Driving Circuit Multiple Current Paths Voltage Drop
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Solution Overview
Problem
In OLED display panels, the high current through a single power source line causes significant voltage drop, leading to uneven brightness across pixels, affecting the viewing quality.
Innovation Solution
The implementation of two or more current paths through switching elements, each connected to a different power source, allows for separate control and adjustment of currents to each OLED, reducing voltage drop and enhancing brightness uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If high current is provided through a single power source line to OLED pixels, then sufficient current for light emission is achieved, but significant voltage drop occurs causing uneven brightness across pixels
Solution Approach 1:
The single power source line is segmented into multiple power source lines (first power source line, second power source line, etc.). Each pixel receives current through multiple parallel current paths from different power source lines, distributing the current load and reducing voltage drop on any single line, thereby improving brightness uniformity across the display panel
Solution Approach 2:
The patent transitions from a single-dimensional current path to a multi-dimensional current distribution network. By introducing multiple power source lines and switching elements arranged in a two-dimensional grid pattern, the system creates redundant current paths that operate in parallel, effectively adding spatial dimensions to the current delivery system and reducing the impact of voltage drops
2Manufacturing precision
If multiple current paths with separate power sources are used, then voltage drop is reduced and brightness uniformity is improved, but circuit complexity increases due to additional switching elements and power source lines
Solution Approach 1:
Multiple switching elements (first switching element, second switching element, etc.) are merged into a single integrated switching circuit within each pixel. The control ends of these switching elements are connected together and controlled by a single scan signal, allowing coordinated control of multiple current paths without requiring separate control circuits for each path, thus managing complexity while maintaining brightness uniformity
Solution Approach 2:
The switching elements serve multiple functions: they act as current switches to control current flow from different power source lines, and their control ends serve as common connection points for scan signals. This multi-functionality reduces the need for additional dedicated control components, balancing circuit complexity with performance requirements
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 voltage drop and improves brightness consistency across pixels, enhancing the overall viewing quality of OLED displays by distributing current through multiple parallel paths.
Implementation Method 1
a light-emitting component, wherein the light-emitting component comprises: a first light-emitting diode arranged to receive the first current from the first current path; and a second light-emitting diode arranged to receive the second current from the second current path
Data Source
AI summary
A display panel has a plurality of OLED pixels arranged in rows and columns. The pixel driving circuit has two or more current paths through a plurality of switching elements for providing the necessary current to the OLEDs in a pixel. The control end of each switching element is connected to the control end of the other switching elements, but each switching element has a separate power source which can be separately adjustable. In some embodiments, in a pixel or sub-pixel, one switching element is located at one end and one switching element is located at the other end of a pixel length, and each pixel is adjacent to a first power source line and a second power source line along the pixel length for separately providing the electrical power to two switching elements.