Display Panel Inspection Line Transistor Voltage Drop Compensation
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Solution Overview
Problem
As display panels increase in size, the elongation of outside inspection lines leads to increased resistance values, making it difficult to detect cracks and requiring additional space for matching resistance designs, and existing methods struggle to prevent voltage drops due to wire resistance.
Innovation Solution
Incorporating a series of transistors in the outside inspection line, where at least one transistor is positioned in a region with high wire resistance, designed to minimize voltage drop, allowing for crack detection regardless of inspection line length by applying different inspection voltages and control signals to initialize and emit pixels with specific grayscales.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If the display panel size is increased, then the display area is improved, but the outside inspection line length increases causing resistance value increase and voltage drop
Solution Approach 1:
A compensation transistor is introduced as an intermediary component between the inspection line and the pixel electrode. This transistor compensates for the voltage drop caused by increased wire resistance in larger display panels, thereby maintaining reliable crack detection accuracy without limiting the display size
Solution Approach 2:
The invention changes the electrical parameters of the inspection circuit by adding a compensation transistor with specific on-resistance characteristics. This transistor is designed to provide compensatory voltage that counteracts the voltage drop in the inspection line, allowing the system to maintain detection sensitivity despite increased line length and resistance
2Area of stationary object
If the outside inspection line length is increased to cover larger panels, then the inspection coverage is improved, but the resistance value increases making crack detection difficult
Solution Approach 1:
The compensation transistor serves as an intermediary that actively compensates for the increased resistance in longer inspection lines. By controlling this transistor, the system can maintain sufficient voltage levels at the pixel electrode even when the inspection line extends across larger panel areas, thereby preserving measurement precision
Solution Approach 2:
The compensation transistor is configured to provide preliminary voltage compensation before the inspection signal reaches the pixel electrode. This preliminary action counteracts the expected voltage drop due to line resistance, ensuring that the inspection signal maintains its integrity throughout the extended inspection line
3Reliability
If transistors are added to the outside inspection line to compensate for voltage drop, then voltage stability is improved, but device complexity increases
Solution Approach 1:
Rather than uniformly complicating the entire inspection line, the invention applies the compensation transistor only at the critical location where voltage drop occurs - at the pixel electrode connection point. This localized approach improves voltage stability without unnecessarily increasing complexity throughout the entire inspection line
Data Source
AI summary
A display panel is disclosed. In one aspect, the display panel includes a display unit including a plurality of pixels, an inspection circuit configured to apply a first inspection voltage to the display unit based on a first control signal, a pad portion electrically connected to the inspection circuit and configured to supply the first inspection voltage and the first control signal to the inspection circuit, and at least one external inspection line electrically connected between the inspection circuit and the pad portion. The external inspection line includes a plurality of transistors.