Display Sub-Pixel Equipotential Node Control for Leakage Current
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Solution Overview
Problem
Light emitting display devices face errors in sensing voltage due to leakage currents caused by misaligned light emitting elements, leading to inaccurate threshold voltage compensation.
Innovation Solution
A display device configuration with a sub-pixel structure that includes multiple light emitting elements and transistors, where the second transistor ensures the first and second nodes have the same potential, preventing driving current leakage and allowing predictable current flow, thereby minimizing errors in sensing voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If light emitting elements are arranged without strict alignment control, then manufacturing complexity is reduced, but leakage current occurs causing sensing voltage errors
Solution Approach 1:
The patent connects the first node and second node to the same power voltage line, making them equipotential. This eliminates the voltage difference that would drive leakage current through misaligned light emitting elements, thereby preventing sensing voltage errors while allowing relaxed alignment tolerances during manufacturing
2Measurement precision
If sensing is performed in conventional manner, then threshold voltage compensation is achieved, but leakage current from reverse-direction elements causes measurement errors
Solution Approach 1:
By making the first node and second node equipotential through connection to the same power voltage line, the patent eliminates the voltage differential that drives leakage current. This allows accurate sensing of threshold voltage without interference from leakage currents generated by misaligned or reverse-direction light emitting elements
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
Prevents errors in sensing voltage due to leakage currents, ensuring accurate threshold voltage compensation and consistent performance across sub-pixels.
Implementation Method 1
a second transistor configured to control a connection between the first node and the second node according to a sensing enable signal of the sensing enable signal line
Implementation Method 2
a first transistor configured to supply a driving current to the first node according to a voltage of a gate electrode of the first transistor
Data Source
AI summary
A display device including a scan line extending in a first direction, a sensing scan line extending in the first direction and spaced from the scan line, a data line extending in a second direction crossing the first direction, a sensing line extending in the second direction and spaced from the data line, a sensing enable signal line extending in the second direction and spaced from the data line and the sensing line, and a sub-pixel connected to the scan line, the sensing scan line, the data line, the sensing line, and the sensing enable signal line. The sub-pixel includes a plurality of light emitting elements between a first node and a second node, a first transistor configured to supply a driving current to the first node according to a voltage of a gate electrode, and a second transistor to control a connection between the first and second nodes.