Pixel Circuit Timing for Threshold Compensation at High Scan Rates
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing pixel circuits struggle to achieve high-frequency driving while sufficiently compensating for the threshold voltage of the driving transistor.
Innovation Solution
A pixel circuit design that includes a light-emitting element, a driving circuit, a first and second energy storage circuit, a data writing circuit, and a compensation control circuit, which performs threshold voltage compensation and data voltage writing in a time-division manner to achieve high-frequency driving.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional pixel circuit design is used, then threshold voltage compensation can be achieved, but high-frequency driving cannot be achieved
Solution Approach 1:
The pixel circuit is divided into multiple functional modules: driving circuit (including driving transistor and storage capacitor), compensation circuit (including compensation transistor and compensation capacitor), and reset circuit. This segmentation allows each module to operate independently and efficiently, enabling high-frequency driving while maintaining adequate threshold voltage compensation through the dedicated compensation circuit
2Reliability
If threshold voltage compensation is sufficiently performed, then driving transistor performance is improved, but scanning signal frequency cannot be increased
Solution Approach 1:
The compensation circuit performs threshold voltage compensation in advance during the compensation phase before the data writing phase. The compensation transistor adjusts the gate voltage of the driving transistor to compensate for threshold voltage variations. This preliminary compensation action ensures that the driving transistor is properly calibrated before high-frequency operation begins, allowing both adequate compensation and high scanning frequencies
3Productivity
If pixel circuit operates at high frequency, then productivity is improved, but threshold voltage compensation becomes insufficient
Solution Approach 1:
The pixel circuit operates in continuous phases: reset phase, compensation phase, data writing phase, and light emission phase. The compensation circuit continuously performs threshold voltage compensation in the compensation phase before each data writing phase. This continuous cyclic operation ensures that threshold voltage compensation is repeatedly performed at high frequency, matching the display refresh rate while maintaining adequate compensation throughout operation
Data Source
AI summary
A pixel circuit, a pixel driving method and a display device. The pixel circuit includes a light-emitting element, a driving circuit, a first energy storage circuit, a second energy storage circuit, a data writing circuit, and a compensation control circuit. The data writing circuit controls writing of a data voltage on a data line into a data writing node under control of a scanning signal. The compensation control circuit controls whether a second node is connected with or disconnected from a compensation node under control of a first reset signal. The compensation node is electrically connected to a third node, and/or, the compensation node is electrically connected to a second terminal of the driving circuit. The present disclosure can achieve high-frequency driving under the premise of sufficient compensating for the threshold voltage of the driving transistor included in the driving circuit.