Display device and method of driving the same
US6697057B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 26, 2001 |
| Grant date | Feb 24, 2004 |
| Priority date | — |
| Expiry date | Nov 12, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10K59/12
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In a conventional EL display device, a general video signal (analog signal voltage) is sampled to be outputted to a source signal line and then inputted to a gate electrode of a driving TFT provided in each pixel. The drain current of the TFT is controlled to control the current flowing into an EL element, thereby adjusting the luminance. However, accurate gray scales cannot be obtained unless the video signal is converted before it is sampled and inputted to the source signal line since the drain current of the driving TFT does not correspond to the gate voltage of the driving TFT linearly. The invention solve this problem by converting an inputted analog signal voltage into a current, converting the current into the gate-source voltage of a correction TFT that has the same polarity as a driving TFT, supplying the gate-source voltage as a source line signal to a source signal line, and applying the source line signal to a gate electrode of the driving TFT. Thus an EL element can emit light at a luminance linearly corresponding to the inputted analog signal voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.