TFT pixel threshold voltage compensation circuit with a source follower
US11170719B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 10, 2020 |
| Grant date | Nov 9, 2021 |
| Priority date | — |
| Expiry date | Dec 10, 2040 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10K59/12
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An enhanced pixel circuit for a display device provides separate compensation and data programming phases to permit minimization of the programming time. Variations in voltage supplies are accounted for by isolating the drive transistor from such power supply by using a second drive transistor configured as source follower relative to the first drive transistor. An on bias stress transistor is incorporated that can electrically connect the first drive transistor to the power supply during an on bias stress operation. During such operation, a voltage stress is applied to eliminate hysteresis effects associated with the drive transistor. The on bias stress operation may be performed as part of a refresh operation during which a data voltage is programmed to the pixel circuit, or as part of a low frequency operation during which a previously programming data voltage is maintained which reduces power consumption.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.