OLED Pixel Circuit Layout for Uniform Overlap Capacitance
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Solution Overview
Problem
Existing display devices face challenges in achieving improved display quality, particularly in the integration of transistors and light emitting elements for efficient pixel control.
Innovation Solution
A display device is designed with a base layer, a circuit layer including specific pixel circuits, and a light emitting element layer. The pixel circuits incorporate driving transistors with oxide semiconductors, and the light emitting elements have a unique electrode and emission layer configuration to optimize overlap areas with the gate conductive layer, ensuring equal capacitance between capacitors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the light emitting element and gate conductive layer are positioned to create overlap area for capacitance, then the display quality improves, but the manufacturing precision requirements increase
Solution Approach 1:
The patent applies equipotentiality by ensuring that adjacent pixels have equal overlapping areas between the light emitting element and gate conductive layer. This creates uniform capacitance values across different pixels, eliminating potential differences in electrical characteristics and ensuring consistent display quality throughout the display device.
Solution Approach 2:
The patent changes the geometric parameters of the light emitting element and gate conductive layer to achieve equal overlapping areas. By adjusting the position and dimensions of these components, the patent ensures that the overlap area creates consistent capacitance values, thereby improving display quality through parameter optimization.
2Reliability
If the pixel circuit and light emitting element are integrated with overlapping areas, then the display performance improves, but the device complexity increases
Solution Approach 1:
The patent merges the pixel circuit and light emitting element into an integrated structure where the gate conductive layer of the pixel circuit overlaps with the light emitting element to form a capacitor. This combining of functions reduces the need for separate capacitor structures and simplifies the overall device architecture while maintaining improved display performance.
Solution Approach 2:
The gate conductive layer serves multiple functions: it acts as the gate electrode for the transistor in the pixel circuit and simultaneously serves as one electrode of the capacitor. This multi-functionality reduces the total number of components needed and simplifies the device structure while achieving both pixel control and capacitance functions.
Data Source
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AI summary
Provided is a display device including: a base layer; a circuit layer including a 1-1 pixel circuit and a 1-2 pixel circuit and disposed on the base layer; and a light emitting element layer including a first light emitting element and a second light emitting element each including a first electrode, an emission layer, a second electrode, and a pixel defining film in which a pixel opening exposing a portion of the first electrode is defined, and disposed on the circuit layer, wherein the 1-1 pixel circuit and the 1-2 pixel circuit each include a driving transistor including a source, a drain, an active, and a gate, and a gate conductive layer including the gate, and an area in which the first electrode of the first light emitting element overlaps the gate conductive layer of the 1-1 pixel circuit when viewed on a plane is equal to an area in which the first electrode of the second light emitting element overlaps the gate conductive layer of the 1-2 pixel circuit when viewed on a plane, and display quality may thus be improved.