Organic electroluminescent display, driving method and pixel circuit thereof
AssigneeSamsung SDI Co., Ltd.
InventorOh-Kyong Kwon
Life of this patent
Estimating the term…
Abstract
Disclosed is an OELD and a pixel circuit which comprise: an organic EL element for emitting light corresponding to a supplied current; a first switch for switching data voltage supplied to a data line in response to a select signal supplied to a scan line; a first TFT for supplying the current to the organic EL element in response to the data voltage supplied to a gate of the first TFT via the first switch; a second TFT having a gate coupled to the gate of the first TFT and compensating for a deviation of a threshold voltage of the first TFT; and a capacitor for maintaining the data voltage supplied to the gate of the first TFT during a predetermined time.
Claims34
An organic electroluminescent display (OELD), comprising:
- a plurality of data lines for transmitting data voltages for representing image signals;
- a plurality of scan lines for transmitting select signals;
- and
- a plurality of pixel circuits respectively formed on a plurality of pixels defined by the data lines and the scan lines,
- wherein each of the pixel circuit comprises:
- an organic electroluminescent (EL) element for emitting light corresponding from a supplied current;
- a first switch for switching data voltage supplied to a data line in response to a select signal supplied to a scan line;
- a first thin film transistor (TFT) for supplying the current to the organic EL element in response to the data voltage supplied to a gate of the first TFT via the first switch;
- a second TFT having a gate coupled to the gate of the first TFT and compensating for a threshold voltage deviation of the first TFT;
- and
- a capacitor for maintaining the data voltage supplied to the gate of the first TFT during a predetermined time.
A method for driving an organic electroluminescent display (OELD) including a plurality of data lines, a plurality of scan lines crossing the data lines, and a plurality of matrix type pixels having thin film transistors (TFTs) formed in regions defined by the data lines and the scan lines and supplying current to organic electroluminescent (EL) elements, comprising the steps of:
- supplying a data voltage for representing image signals to the data lines;
- sequentially supplying a select signal for selecting a pixel row to the scan lines;
- switching the data voltage supplied to the data lines in response to the select signal, and compensating the supplied data voltage to reduce a threshold voltage deviation of the TFT;
- and
- transmitting the compensated data voltage to a gate of the TFT, and supplying the current to the organic EL element.
An organic electroluminescent display (OELD) pixel circuit formed on a plurality of pixels defined by a plurality of data lines and scan lines, comprising:
- an organic electroluminescent (EL) element;
- a first thin film transistor (TFT) having a drain coupled to the organic EL element;
- a second TFT having a gate coupled to a gate of the first TFT, and the gate and a drain of the second TFT being coupled together;
- a first switch having a control terminal coupled to the scan line, and having a first terminal and a second terminal respectively coupled to the data line and a source of the second TFT;
- and
- a capacitor coupled between the gate and a source of the first TFT.
Dependencies are inferred from the claim text.