Negative Impedance Sensing Circuit for Display Panel Accuracy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Light emitting display devices face challenges in sensing accuracy due to impedance deviations between sensing lines, which affect the performance and lifetime of the display panel.
Innovation Solution
A light emitting display device with a display panel including sensing lines, a data driver, and a sensing circuit that generates a negative impedance value to cancel impedance differences between sensing lines, allowing for accurate sensing voltage detection and compensation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional sensing circuits are used without impedance calibration, then the device complexity is low, but the sensing accuracy deteriorates due to impedance differences between sensing lines
Solution Approach 1:
The patent applies preliminary action by performing impedance calibration before normal sensing operations. The calibration process pre-determines impedance compensation values for each sensing line, which are then used during actual sensing to cancel out impedance differences. This preliminary calibration step ensures high sensing accuracy without requiring complex real-time adjustment mechanisms during operation.
Solution Approach 2:
The patent changes the impedance parameter of sensing lines by introducing compensation values that offset the inherent impedance differences between lines. By adjusting the electrical parameters (impedance) of the sensing lines through calibration data, the system achieves uniform sensing characteristics across all lines, thereby improving measurement precision without fundamental structural changes.
2Measurement precision
If impedance calibration is performed to cancel impedance differences, then the sensing accuracy is improved, but the time required for voltage detection increases
Solution Approach 1:
The calibration process is performed in advance during manufacturing or initialization, storing compensation values for later use. During actual sensing operations, the pre-calculated compensation values are simply applied, requiring minimal additional time. This separates the time-consuming calibration step from the time-critical sensing step, resolving the contradiction between accuracy and detection time.
Solution Approach 2:
The patent creates a copy or model of the impedance characteristics for each sensing line through calibration, storing these as compensation values. During sensing, instead of performing complex real-time impedance matching, the system uses these pre-created compensation copies to quickly adjust for impedance differences, maintaining high accuracy while minimizing detection time.
3Measurement precision
If negative impedance values are generated to cancel impedance differences, then the sensing voltage accuracy is improved, but the device complexity increases due to additional calibration circuitry
Solution Approach 1:
The patent introduces an intermediary element - the calibration circuit and compensation values - that mediates between the sensing lines and the sensing circuit. This intermediary performs the complex impedance matching function, allowing the main sensing circuit to remain relatively simple while still achieving high voltage accuracy through the calibration layer.
Solution Approach 2:
The sensing system performs self-calibration by automatically determining and applying compensation values for its own impedance variations. This self-service approach eliminates the need for external complex calibration equipment, achieving high accuracy through the system's own integrated calibration capabilities with minimal additional complexity.
Data Source
AI summary
A light emitting display device includes a display panel configured to display an image, a data driver configured to supply a data voltage to data lines of the display panel, and a sensing circuit configured to obtain a sensing voltage through sensing lines of the display panel after reflecting a negative impedance value canceling impedance differences of the sensing lines.