OLED Display Voltage Measurement Convergence Speed
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional display devices using organic electroluminescent elements face challenges in quickly measuring electrical characteristics due to the need for a detection voltage to converge to a steady state, which prolongs the measurement time and is exacerbated by parasitic capacitance in larger display devices.
Innovation Solution
A display device and method that includes a light-emitting element, a capacitor, a drive transistor, a voltage detection line, a switching element, a voltage generation unit, a current detection unit, and a control unit, where the test voltage is updated based on the direction of current through the switching element, allowing for quick measurement of electrical characteristics without waiting for the detection voltage to converge.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the detection voltage is allowed to converge to the steady state before measurement, then the measurement accuracy is improved, but the measurement time is prolonged
Solution Approach 1:
The patent applies preliminary action by pre-charging the conductive line before voltage measurement to reduce the convergence time. The conductive line is pre-charged to a predetermined voltage level before the actual measurement, which accelerates the voltage convergence process and enables faster accurate measurement without waiting for complete steady state
Solution Approach 2:
The patent uses feedback by monitoring the voltage convergence status in real-time and determining when the voltage has stabilized. The measurement control circuit detects whether the voltage on the conductive line has converged to within a predetermined range, and only then proceeds with the measurement, ensuring accuracy while minimizing unnecessary waiting time
2Stability of the object's composition
If the conductive line is pre-charged to stabilize the detection voltage, then the voltage stability is improved, but the convergence time is prolonged
Solution Approach 1:
The conductive line is pre-charged to a predetermined voltage level before the actual measurement operation. This preliminary charging action stabilizes the voltage on the conductive line in advance, reducing the time required for voltage convergence during the measurement process while maintaining voltage stability
Solution Approach 2:
The patent changes the voltage parameter on the conductive line by applying a pre-charging voltage that is different from the measurement voltage. This parameter change accelerates the convergence process by starting from a voltage level closer to the final steady state, thereby reducing convergence time while maintaining stability
Data Source
AI summary
A display device includes: an organic electroluminescent element; a capacitor; a drive transistor; a data line; a test transistor which switches between conduction and non-conduction between the data line and an anode electrode of the organic electroluminescent element; a voltage generation unit which supplies the data line with a test voltage for measuring an anode voltage of the organic electroluminescent element; a current detection unit which detects a current through the test transistor when a test transistor is in a conducting state, while the voltage generation unit is applying the test voltage to the data line; a control unit which updates the voltage value of the test voltage, based on a direction of the current detected by the current detection unit, and causes the voltage generation unit to output the updated test voltage.