Active-Matrix Display Device with Non-Overlapping Source Line and Electrode
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Solution Overview
Problem
In top-emission active-matrix display devices, parasitic capacitance occurs due to overlapping source lines and electrode layers, leading to voltage variations and crosstalk, which degrades display quality.
Innovation Solution
The active-matrix display device is designed with a power supply line shared between adjacent pixels in a direction perpendicular to the source line, ensuring that the data line and metal electrode layer do not overlap, reducing parasitic capacitance and crosstalk.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the source line and metal electrode layer are arranged to overlap in top-emission display devices, then the wiring can be simplified and pixel area can be reduced, but parasitic capacitance occurs causing voltage variation and crosstalk that degrades display quality
Solution Approach 1:
The patent transitions from a planar overlapping arrangement to a three-dimensional stacked arrangement where the source line is positioned in a lower layer and the metal electrode layer is positioned in an upper layer, separated by an insulating layer. This dimensional separation eliminates parasitic capacitance while maintaining compact pixel area.
Solution Approach 2:
An insulating layer is introduced as an intermediary between the source line and the metal electrode layer. This intermediary layer physically separates the two conductive elements, preventing direct electrical interaction and eliminating parasitic capacitance formation.
2Ease of manufacture
If power supply lines are provided for each pixel row, then power supply is simplified, but the number of power supply lines increases leading to reduced aperture ratio and degraded image quality
Solution Approach 1:
The patent merges the power supply function for two adjacent pixel rows into a single shared power supply line. This power supply line is positioned to extend in the row direction and electrically connect to both rows, reducing the total number of power supply lines while maintaining adequate power distribution.
Solution Approach 2:
The shared power supply line serves multiple pixel rows simultaneously, making it a multi-functional element. This universal power supply approach reduces the overall line count and increases the aperture ratio while still providing power to all required pixels.
3Device complexity
If the data line and metal electrode layer are arranged to overlap, then wiring complexity is reduced, but parasitic capacitance causes voltage variation transfer that degrades display quality
Solution Approach 1:
The patent resolves the conflict by arranging the data line and metal electrode layer in different vertical layers rather than having them overlap in the same plane. The data line is positioned in a lower layer while the metal electrode layer is in an upper layer, separated by insulating layers, thus eliminating parasitic capacitance while maintaining wiring efficiency.
Solution Approach 2:
Insulating layers are positioned between the data line and metal electrode layer to act as intermediaries that prevent electrical interaction. This separation eliminates the parasitic capacitance pathway while allowing both conductors to exist in close proximity for efficient wiring.
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 enhances display quality by minimizing voltage variations and crosstalk, while also reducing the number of power supply lines, allowing for wider wiring and improved circuit characteristics.
Implementation Method 1
a light-emitting element, such as an organic EL element
Data Source
AI summary
An active-matrix display device according to the present disclosure includes a plurality of pixels. Each of the pixels includes: a drive transistor disposed on a substrate; and an organic EL element that is caused by the drive transistor to emit light and includes an AM layer disposed above the substrate and a transparent electrode layer disposed above the AM layer. The active-matrix display device further includes: a source line that supplies data to the pixels; and a power supply line that supplies electric power to the pixels. The power supply line is shared by, among the plurality of pixels, two pixels that are adjacent to each other in a second direction that crosses a first direction in which the power supply line is extended. The source line and the AM layer are disposed not to overlap each other in a plan view of the substrate.