Auxiliary Electrode Shields Drive Circuit in OLED Pixel Unit
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Solution Overview
Problem
Long-term irradiation affects the performance of thin film transistors in light emitting diode display substrates, leading to leakage currents that degrade the display effect.
Innovation Solution
Incorporating an auxiliary electrode made of opaque conductive material within each pixel unit to shield the drive circuit from light, reducing direct irradiation and connecting it in parallel with the cathode to form a structure with lower resistance, thereby reducing power consumption and leakage currents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the drive circuit is exposed to light for normal display operation, then the light emitting diode can emit light, but long-term irradiation causes leakage current in the thin film transistor
Solution Approach 1:
The pixel unit is divided into two distinct regions: a light-emitting region containing the light emitting diode, and a shielded region containing the drive circuit. The auxiliary electrode creates a clear spatial separation between the area requiring light exposure and the area requiring protection from light, allowing each component to function optimally without interfering with the other.
Solution Approach 2:
The harmful light irradiation is extracted or removed from the drive circuit area by introducing the auxiliary electrode. This electrode selectively blocks light from reaching the thin film transistor while permitting light to reach the light emitting diode, thereby eliminating the harmful effect without affecting the desired light emission function.
2Reliability
If an auxiliary electrode is added to shield the drive circuit, then leakage current is reduced, but the device structure becomes more complex
Solution Approach 1:
The auxiliary electrode serves multiple functions simultaneously: it acts as a light-shielding layer to protect the drive circuit, functions as an electrical connection element by being connected to the cathode, and contributes to forming the overall pixel structure. This multi-functionality reduces the need for separate dedicated components for each function.
Solution Approach 2:
The auxiliary electrode is integrated with the cathode of the light emitting diode, merging two functional elements into a connected structure. This integration simplifies the overall device architecture by reducing the number of discrete components and their associated interconnections, thereby lowering manufacturing complexity.
3Reliability
If the auxiliary electrode covers the drive circuit, then light irradiation is blocked, but the area available for other components is reduced
Solution Approach 1:
Light shielding is applied locally only to the drive circuit region where thin film transistors are located, rather than uniformly across the entire pixel unit. The auxiliary electrode is positioned and shaped to provide protection precisely where needed, leaving other areas of the pixel unit available for light emission and other functional components.
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
The auxiliary electrode effectively blocks light from reaching the drive circuit, minimizing leakage currents and enhancing the display effect while reducing power consumption by forming a lower resistance integral structure with the cathode.
Implementation Method 1
the auxiliary electrode is made of an opaque conductive material, so as to block light irradiated at the portion of the drive circuit that is covered by the auxiliary electrode
Implementation Method 2
connecting it in parallel with the cathode to form a structure with lower resistance, thereby reducing power consumption and leakage currents
Data Source
AI summary
The present disclosure provides a display substrate which includes: a plurality of pixel units, at least one of which includes a light emitting diode and a drive circuit. The light emitting diode includes a cathode; the display substrate further includes an auxiliary electrode layer including at least one auxiliary electrode. The auxiliary electrode is disposed in at least one of the pixel units. The auxiliary electrode is electrically connected with the cathode of the light emitting diode which is located in the same pixel unit as the pixel unit that the auxiliary electrode is located in, and the auxiliary electrode covers at least a portion of the drive circuit in the pixel unit that the auxiliary electrode is located in. The auxiliary electrode is made of an opaque conductive material, so as to block light irradiated at the portion of the drive circuit that is covered by the auxiliary electrode.