Pixel circuit with reduced sensitivity to threshold variations of the diode connecting switch
US11189225B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 23, 2020 |
| Grant date | Nov 30, 2021 |
| Priority date | — |
| Expiry date | Sep 23, 2040 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G2300/0861
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A pixel circuit that drives a light-emitting device employs a diode-connection compensation scheme that compensates for threshold variations of the diode connecting switch that diode connects the drive transistor during a threshold compensation phase. The pixel circuit operates to reduce the impact of threshold voltage variations of the diode connecting switch to improve brightness uniformity and picture quality. The pixel circuit includes two compensation capacitors in addition to the storage capacitor for data programming to control the flow and magnitude of a rebalancing current through the diode connecting switch in such a way to cancel excess or deficit of charge caused by threshold voltage variations of the diode connecting switch due to capacitive coupling between the gate node of the switch and the storage capacitor. Therefore, the circuit configuration employs a triple-capacitor structure to significantly improve compensation performance and reliability.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.