OLED Protection Circuit Using Transistor to Divert ESD
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Organic light emitting display devices are prone to burning and defective driving due to unintentional electrostatic discharge (ESD) and overcurrent issues, particularly when flexible printed circuit boards are misaligned or high voltages are applied, leading to potential damage and operational failures.
Innovation Solution
A protection circuit is integrated into the signal input lines of the display panel, comprising protection transistors with specific electrode connections and phase-differenced clock signals to manage power sourcing and divert ESD, ensuring the OLED is protected from excessive voltage and maintaining normal operation even when the power source floats.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If signal input lines are used to transmit driving power and signals from pad part to display panel, then normal driving operation is enabled, but the display panel becomes vulnerable to ESD and overcurrent damage
Solution Approach 1:
The protection transistor is introduced as an intermediary component between the signal input line and the display panel circuitry. This transistor acts as a mediator that selectively allows normal signals to pass through while blocking harmful ESD and overcurrent, thus protecting the display panel without requiring fundamental changes to the existing signal transmission architecture.
Solution Approach 2:
The protection transistor is configured to preemptively counteract harmful effects before they can damage the display panel. By monitoring the signal input line and activating protective action in advance when abnormal conditions (ESD or overcurrent) are detected, the system prevents damage before it occurs, rather than responding after damage has happened.
2Reliability
If protection circuit is added to protect against ESD and overcurrent, then reliability is improved, but device complexity increases
Solution Approach 1:
The protection transistor serves multiple functions simultaneously: it acts as a normal signal transmission path during regular operation, functions as an ESD protection mechanism when electrostatic discharge occurs, and provides overcurrent protection when excessive current is detected. This multi-functionality reduces the need for separate dedicated protection circuits for each threat type.
Solution Approach 2:
The protection function is merged with the existing signal input line structure rather than being implemented as a completely separate parallel system. The protection transistor is integrated into the signal path, combining protection functionality with the existing circuit architecture, thereby minimizing additional complexity while achieving comprehensive protection.
Data Source
AI summary
An organic light emitting display device includes a display panel, a pad part positioned at one side of the display panel and having a plurality of pads arranged to receive driving power and driving signals, a plurality of signal input lines arranged to transmit the driving power and the driving signal from the pad part to the display panel, and a protection circuit connected to one or more of the signal input lines, wherein the protection circuit includes a first protection transistor including a gate electrode, a first electrode, and a second electrode, wherein the signal input lines include a first clock signal input line, the first electrode is connected to the first clock signal input signal line, and the second electrode is connected to a first power source.