Claims
- 1. A circuit for driving a current mode light modulating device, comprising:
a capacitor for storing a data voltage; a field effect transistor (FET) controlled by a signal on a scan line, for coupling said data voltage from a signal line to said capacitor; and a current source, controlled by said stored data voltage, for driving said device with current provided from a power line, wherein said power line is in a plane that is geometrically parallel to a plane within which said scan line is located.
- 2. The circuit of claim 1,
wherein said device has a terminal connected to a common electrode, and wherein said power line has a waveform thereon that operates in cooperation with a waveform on said common electrode to reverse bias said device to reduced trapped charge.
- 3. The circuit of claim 1,
wherein said device has a terminal connected to a common electrode, wherein said power line has a first waveform thereon, said signal line has second waveform thereon and said common electrode has a third waveform thereon, and wherein said first, second and third waveforms cooperate with one another to reduce a threshold voltage shift of said current source.
- 4. The circuit of claim 1,
wherein said device has a terminal connected to a common electrode, wherein said power line has a first waveform thereon, said signal line has second waveform thereon, said common electrode has a third waveform thereon, and said scan line has a fourth waveform thereon, and wherein said first, second third and fourth waveforms cooperate with one another to control said device.
- 5. The circuit of claim 1,
wherein said FET and said current source are connected to a common node, and wherein said capacitor is connected between said common node and said power line.
- 6. The circuit of claim 5, wherein said capacitor employs a displacement current through bootstrapping to facilitate said storage of said data voltage.
- 7. The circuit of claim 1, wherein said power line has an alternating current (AC) waveform thereon.
- 8. The circuit of claim 1, wherein said device has a terminal connected to a common electrode with an alternating current (AC) waveform thereon.
- 9. The circuit of claim 1, wherein said device is an organic light emitting diode (OLED).
- 10. The circuit of claim 1,
wherein said circuit is a member of a plurality of such circuits configured in a row, and wherein said power line and said scan line are connected to said plurality of circuits.
- 11. The circuit of claim 10,
wherein said row is a first row in an array, wherein said power line is a first power line and said scan line is a first scan line, wherein said array includes a second row of said circuits, and wherein said second row is connected to a second power line and a second scan line.
- 12. The circuit of claim 1, wherein said FET and said current source comprise amorphous silicon.
- 13. The circuit of claim 12, wherein said current source is biased in its saturation region.
- 14. The circuit of claim 12, wherein said current source is biased to allow current flow less than 100% of the time.
- 15. An active matrix organic light emitting diode (AMOLED) display comprising:
a plurality of pixel circuits in a row, wherein each of said pixel circuits includes:
(a) a capacitor for storing a data voltage; (b) a first field effect transistor (FET) controlled by a signal on a scan line, for coupling said data voltage from a signal line to said capacitor; and (c) a second FET, controlled by said stored data voltage, for driving an AMOLED in said display with current provided from a power line, wherein said power line is in a plane that is geometrically parallel to a plane within which said scan line is located, and wherein said power line and said scan line are connected to each of said pixel circuits in said row.
- 16. The circuit of claim 15, wherein said first and second FET comprise amorphous silicon.
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is claiming priority of U.S. Provisional Patent Application Serial No. 60/332,389, filed on Nov. 20, 2001.
Provisional Applications (1)
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Number |
Date |
Country |
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60332389 |
Nov 2001 |
US |