Display Pixel Protection Circuit for Luminance Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing display devices face issues with overcurrent, voltage drop, and luminance irregularity due to internal resistance differences in the common electrode of light emitting diodes, leading to burnt defects and poor image quality.
Innovation Solution
Incorporation of a protection circuit with an auxiliary electrode and protection transistor connected in series between the common electrode of the light emitting diode and the power line, which compensates for voltage drops and suppresses overcurrent.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a common electrode is used for light emitting diodes, then device complexity is reduced, but voltage drop and luminance irregularity increase due to internal resistance differences
Solution Approach 1:
The common electrode is segmented into multiple independent electrodes, each connected to a separate power supply terminal. This segmentation allows independent voltage control for each electrode region, compensating for internal resistance differences and achieving uniform luminance across the display while maintaining relatively simple device structure.
2Illumination intensity
If high current is supplied to light emitting diodes, then luminance intensity increases, but overcurrent causes burnt defects
Solution Approach 1:
The system incorporates feedback control by monitoring the actual voltage and current supplied to each light emitting diode through separate power supply terminals. This feedback mechanism enables real-time adjustment of driving currents, ensuring optimal luminance output while preventing overcurrent conditions that could cause burnt defects.
Solution Approach 2:
The patent changes the electrical parameters (voltage and current) supplied to each light emitting diode independently through separate power supply terminals. By dynamically adjusting these parameters based on actual device characteristics and operating conditions, the system achieves high luminance output while preventing overcurrent damage.
3Manufacturing precision
If separate power supply lines are used for each light emitting diode, then voltage drop is minimized, but device complexity increases
Solution Approach 1:
The power supply system is segmented into multiple independent power supply terminals, each providing separate voltage and current control to specific regions or individual light emitting diodes. This segmentation minimizes voltage drop by reducing current density in each power line while maintaining manageable device complexity through modular architecture.
Data Source
AI summary
A pixel includes a light emitting diode which includes a first electrode and a second electrode, a driving transistor which is connected between a second node corresponding to the first electrode of the light emitting diode and a third node corresponding to a first power voltage line configured to supply a first power voltage and generates a driving current flowing to a second power voltage line configured to supply a second power voltage through the light emitting diode from the first power voltage line, a switching transistor which is connected between the first node corresponding to a gate electrode of the driving transistor and a data line and is turned on in response to a gate signal which is supplied to a gate line, a storage capacitor connected between the first node and the second node; and a protection circuit which is connected between the second electrode of the light emitting diode and the second power voltage line. Further, the protection circuit includes an auxiliary electrode and a protection transistor which are connected in series.