OLED Lighting Test Circuit ESD Protection via Resistor
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Solution Overview
Problem
Organic light emitting diode (OLED) displays are susceptible to defects caused by electrostatic discharge (ESD), which can damage thin film transistors and lines in the lighting test circuit, leading to ineffective lighting tests and driving defects.
Innovation Solution
The OLED display incorporates a lighting test circuit with transistors having a channel layer, where the second input line is coupled to a power supply line through a resistor, either the first or second power supply line, to suppress ESD effects and maintain the off state of the transistors during actual driving, preventing defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the lighting test circuit and lines are exposed to external electrostatic discharge, then the manufacturing and testing process can be completed, but the thin film transistors and lines are easily damaged by ESD
Solution Approach 1:
A resistor is introduced as an intermediary component between the second input line (receiving test control signal) and the power supply line. This resistor acts as a protective mediator that limits ESD current flow while allowing normal test operations, thereby preventing direct damage to the thin film transistors during the lighting test process
Solution Approach 2:
The resistor is pre-configured in the circuit design before ESD events occur, providing advance protection by limiting the maximum current that can flow through the thin film transistors. This preemptive measure ensures that even when ESD strikes the lighting test circuit or input lines, the transistors are already protected from excessive current damage
2Productivity
If the second input line is directly connected to the power supply line, then the test control signal can be supplied efficiently, but ESD damage occurs to the transistors
Solution Approach 1:
The resistor serves as a protective intermediary inserted in series between the second input line and the power supply line. It maintains signal transmission capability while simultaneously limiting ESD current, thus resolving the contradiction between efficient test signal supply and ESD protection
3Ease of manufacture
If thin film transistors are damaged by ESD, then the manufacturing process can proceed, but the lighting test cannot be effectively performed and driving defects occur
Solution Approach 1:
The resistor is built into the circuit design before manufacturing completes, providing continuous protection throughout the manufacturing process and subsequent operation. This ensures that the lighting test circuit and transistors remain protected from ESD damage, maintaining both manufacturing continuity and test effectiveness
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 effectively prevents driving defects in OLED displays by suppressing ESD-induced damage to the transistors and ensuring stable operation during both testing and actual use.
Implementation Method 1
the second input line is coupled to the first power supply line or the second power supply line through a resistor
Data Source
AI summary
A display including: pixels; a gate driver for supplying a gate signal to gate lines; a lighting test circuit coupled to a first input line (for transmitting a lighting test signal), and a second input line (for transmitting a test control signal), the light test circuit being for supplying the lighting test signal to data lines according to the test control signal; a first power supply line for supplying a gate high level voltage to the gate driver and at a periphery of the gate driver and the lighting test circuit; and a second power supply line for supplying a gate low level voltage to the gate driver and at a periphery of the gate driver and the lighting test circuit. The second input line is coupled to the first power supply line or the second power supply line through a resistor.