Digital driving method of organic electroluminescent display device
View Patent ↗An organic electroluminescent display device includes a scan line, a data line, a voltage supply line, a switching transistor connected to the scan and data lines, a driving transistor connected to the switching transistor and the voltage supply line, a storage capacitor connected between the switching transistor and the voltage supply line, and an organic light-emitting diode connected to the driving transistor and ground. A black display voltage applied to the data line is supplied to the driving transistor when a first gate ON signal is applied to the scan line. A video data voltage applied to the data line is supplied to the driving transistor when a second gate ON signal is applied to the scan line. The voltages are applied at least once each frame.
1. A driving method for an organic electroluminescent display device, the organic electroluminescent display device comprising a scan line, a data line, a first voltage supply line, a switching thin film transistor connected to the scan and data lines, a driving thin film transistor connected to the switching thin film transistor and the first voltage supply line, a storage capacitor connected between the switching thin film transistor and the first voltage supply line, and an organic light-emitting diode connected to the driving thin film transistor and a second voltage supply line, the method comprising:
a) applying a black display voltage to the data line;
b) applying a first gate ON signal to the scan line to supply the black display voltage to the driving thin film transistor;
c) applying a video data voltage to the data line; and
d) applying a second gate ON signal to the scan line to supply the video data voltage to the driving thin film transistor.
2. The method claim 1 , wherein a), b), c) and d) are performed at least once each frame.
3. The method of claim 2 , wherein an input time of the video data voltage increases at a rate of 2 A , where A is a positive integer including zero and is the number of times a), b), c) and d) are repeated in a particular frame.
4. The method of claim 1 , wherein the switching thin film transistor and the driving thin film transistor are p-type transistors.
5. The method of claim 4 , wherein the black display voltage is a high level voltage and the video data voltage is a low level voltage.
6. The method of claim 4 , wherein the second voltage supply line is grounded.
7. The method of claim 1 , wherein a) and b) are simultaneously performed.
8. The method of claim 7 , wherein c) and d) are simultaneously performed.
9. A driving method for a display device, the display device comprising a scan line, a data line, a first voltage supply line, a switching thin film transistor connected to the scan and data lines, a driving thin film transistor connected to the switching thin film transistor and the first voltage supply line, and a light emitter connected to the driving thin film transistor and a second voltage supply line, the method comprising:
limiting the transistors contained in each pixel to the driving thin film transistor and the switching thin film transistor;
turning the light emitter on and off without altering a voltage applied to a cathode electrode of the light emitter;
a) applying a black display voltage to the data line;
b) applying a first gate ON signal to the scan line to supply the black display voltage to the driving thin film transistor;
c) applying a video data voltage to the data line; and
d) applying a second gate ON signal to the scan line to supply the video data voltage to the driving thin film transistor.
10. The method of claim 9 , wherein a storage capacitor is connected between the switching thin film transistor and the first voltage supply line.
11. The method of claim 9 , wherein the switching thin film transistor and the driving thin film transistor have channels with the same doping type.
12. The method of claim 9 , wherein the second voltage supply line is grounded.
13. The method of claim 9 , wherein a), b), c) and d) are performed at least once each frame.
14. The method of claim 13 , wherein an input time of the video data voltage increases at a rate of 2 A , where A is a positive integer including zero and is the number of times a), b), c) and d) are repeated in a particular frame.
15. The method of claim 9 , wherein at least one of: a) and b) are simultaneously performed or c) and d) are simultaneously performed.
16. The method of claim 9 , wherein the light emitter is a light-emitting diode.
17. The method of claim 16 , wherein the light-emitting diode is an organic light-emitting diode.