OLED Sense-Line Capacitance Measurement With Temperature Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing capacitance value measurement methods for OLED display panels are unable to accurately measure the parasitic capacitance value of external compensation sense lines due to the instability of thin film transistors, which affects the performance of pixel circuits and leads to display defects.
Innovation Solution
A capacitance value measurement method and device that utilize a mapping relation between temperature and parasitic capacitance values of analog-to-digital conversion circuits, allowing for the accurate measurement of parasitic capacitance values by turning on specific switching elements, measuring real-time capacitance values, and using detection capacitors to determine the parasitic capacitance of external compensation sense lines.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If indirect measurement method is used for parasitic capacitance value, then measurement can be performed, but measurement precision deteriorates due to temperature influence on analog-to-digital conversion circuit
Solution Approach 1:
The patent performs preliminary calibration to establish a mapping relationship between temperature and parasitic capacitance values of the analog-to-digital conversion circuit before actual measurements. This preliminary action enables the system to compensate for temperature effects during subsequent measurements, thereby maintaining high measurement precision under varying temperature conditions.
Solution Approach 2:
The patent changes the parameter of temperature compensation by using detection capacitors to measure real-time temperature and applying corresponding compensation values based on the pre-established mapping relationship. This parameter change approach allows the system to adapt to temperature variations and maintain accurate parasitic capacitance measurements.
2Productivity
If multiple switching elements are simultaneously turned on for measurement, then measurement speed improves, but measurement precision deteriorates due to mutual interference
Solution Approach 1:
The patent segments the measurement process by turning on switching elements sequentially rather than simultaneously. Each switching element is activated in isolation, allowing independent measurement of each detection capacitor without mutual interference. This segmentation approach ensures measurement precision while maintaining acceptable measurement speed through efficient sequential operation.
Data Source
AI summary
A capacitance value measurement method and a capacitance value measurement device are provided. The capacitance value measurement method includes steps of: acquiring a first mapping relation; setting a standard temperature t0 of one analog-to-digital conversion circuit; and turning off all switching elements of a corresponding switching circuit other than an Ath switching element, turning on the Ath switching element, measuring a real-time temperature t of an analog-to-digital conversion sub-circuit of the analog-to-digital conversion circuit, measuring a real-time capacitance value Cn of an nth testing point, and acquiring a parasitic capacitance value of an external compensation sense line connected to the Ath switching element at the real-time temperature t of the analog-to-digital conversion sub-circuit in accordance with the real-time capacitance value Cn and the first mapping relation, where A is a positive integer.