LED Display Panel Drive Method for Reverse Polarity Tolerance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In the manufacturing of light emitting diode (LED) display panels, the anode and cathode ends of LED chips need to be correctly connected to the drive circuit to prevent damage from reverse bias and ensure proper illumination, which is challenging due to the potential for incorrect coupling directions during the bonding process.
Innovation Solution
A display panel design that includes a plurality of gate lines, source lines, and transistors, where the LEDs are connected such that a frame time includes at least a first cycle and a second cycle, with the level of the source signal being higher than the drive signal in the first cycle and lower in the second cycle, allowing the LEDs to be turned on regardless of the coupling direction, and optionally utilizing a capacitor to maintain drive signal levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional DC drive method is used with fixed anode and cathode connections, then the LED can be driven correctly when coupling direction is known, but the LED will be damaged by reverse bias or fail to illuminate when coupling direction is incorrect
Solution Approach 1:
The patent applies periodic action by alternating the polarity of the drive signal between first and second cycles. During the first cycle, the drive signal has a first polarity that turns on LEDs with correct coupling direction. During the second cycle, the drive signal switches to a second polarity (opposite to the first) that turns on LEDs with reversed coupling direction. This periodic polarity switching enables the drive circuit to accommodate both correct and incorrect LED coupling directions without damage, resolving the technical contradiction between reliability and device complexity.
2Ease of manufacture
If the anode and cathode ends of LED chips are bonded to the drive circuit, then proper electrical connection can be achieved, but incorrect coupling direction during bonding causes reverse bias damage or failure to illuminate
Solution Approach 1:
The patent implements periodic action through alternating polarity switching in the drive signal. The drive circuit operates in first cycles with a first polarity and second cycles with a second polarity. This periodic polarity alternation allows the manufacturing process to remain simple without requiring precise coupling direction control, while simultaneously ensuring LED connection reliability by accommodating both correct and incorrect coupling directions through the alternating signal polarity.
3Adaptability or versatility
If AC drive signal with alternating polarity is used, then LEDs can be driven regardless of coupling direction, but the drive circuit and control method become more complex
Solution Approach 1:
The patent applies periodic action by implementing a drive signal that alternates between first and second cycles with opposite polarities. During first cycles, the drive signal has a first polarity that activates LEDs with one coupling direction. During second cycles, the drive signal switches to a second polarity that activates LEDs with the opposite coupling direction. This periodic polarity switching provides coupling direction adaptability while maintaining relatively simple drive circuit implementation, resolving the technical contradiction between adaptability and device complexity.
Data Source
AI summary
A display panel includes a plurality of gate lines, a plurality of source lines, a plurality of first transistors and a plurality of light emitting diodes. The control end of each of the first transistors receives a gate signal. The first end of each of the first transistors receives a source signal. The first end of each if the LEDs is electrically connected to the second end of one of the corresponding first transistors. The second end of each of the LEDs receives a drive signal. A frame time of the light emitting diodes includes a first cycle and a second cycle. Within the first cycle of the frame time, the level of the source signal is higher than the level of the drive signal. Within the second cycle of the frame time, the level of the source signal is lower than the level of the drive signal.