Data voltage current drive amoled pixel circuit
View Patent ↗There is provided a circuit for driving an organic light emitting diode (OLED). The circuit includes a current source for providing current to a first terminal of the OLED, and a generator for providing a variable voltage signal to a second terminal of the OLED to facilitate control of the current.
1. A circuit for driving an organic light emitting diode (OLED), comprising:
a current drive transistor for providing current to a first terminal of said OLED;
a capacitor for storing a preset voltage and a data voltage to control said current drive transistor, wherein said capacitor is connected to said first terminal;
a data transistor for adding said data voltage onto said capacitor; and
a generator for providing a variable voltage signal to a second terminal of said OLED to facilitate said control of said current drive transistor,
wherein said variable voltage signal comprises a voltage level for facilitating said storing of said preset voltage.
2. The circuit of claim 1 , wherein said current, when flowing, is substantially independent of a threshold voltage of said current drive transistor.
3. The circuit of claim 1 , wherein said preset voltage and said data voltage are relative to a data reference voltage.
4. The circuit of claim 1 , wherein said variable voltage signal further comprises a voltage level that facilitates said storing of said data voltage.
5. The circuit of claim 1 , wherein said OLED has a capacitance that facilitates said storing of said preset voltage and said data voltage.
6. The circuit of claim 1 , wherein said variable voltage signal comprises a voltage level for turning off said OLED.
7. The circuit of claim 1 , wherein said variable voltage signal comprises a voltage level for facilitating said storing of said data voltage.
8. The circuit of claim 1 , wherein said variable voltage signal comprises a voltage level for allowing luminance of said OLED.
9. The circuit of claim 1 , wherein said variable voltage signal comprises a voltage level for reversing a voltage polarity across said OLED.
10. The circuit of claim 1 , wherein said variable voltage signal comprises a voltage level for reversing a source to drain voltage polarity of said current drive transistor.
11. The circuit of claim 1 , wherein said variable voltage signal comprises a voltage level for reversing a gate to drain voltage polarity of said current drive transistor.
12. The circuit of claim 1 , wherein said current drive transistor and said data transistor are amorphous silicon transistors.
13. A circuit for driving an organic light emitting diode (OLED), comprising:
a current drive transistor for providing current to a first terminal of said OLED;
a capacitor for storing a preset voltage and a data voltage to control said current drive transistor, wherein said capacitor is connected to said first terminal;
a data transistor for adding said data voltage onto said capacitor;
a generator for providing a variable voltage signal to a second terminal of said OLED to facilitate said control of said current drive transistor; and
a data reference voltage transistor for establishing a data reference voltage,
wherein said preset voltage and said data voltage are referenced to said data reference voltage.
14. The circuit of claim 13 , wherein a preset signal controls operation of said data reference voltage transistor.
15. The circuit of claim 14 ,
wherein said circuit is a member of a plurality of circuits in an array of rows and columns, and
wherein said preset signal is provided to said plurality of circuits.
16. The circuit of claim 14 ,
wherein said circuit is in a row of an array that contains a plurality of such circuits, and
wherein said preset signal is provided from a gate line signal that is used by another row in said array.