Electro-optical apparatus and method of driving the electro-optical apparatus
The invention provides an electro-optical apparatus that can prevent a shift in a threshold voltage of an amorphous silicon transistor while driving an organic EL device in a pixel circuit including the amorphous silicon transistor. A characteristic-adjustment circuit can be provided, which has a function of returning a shift in the threshold voltage of the amorphous silicon transistor included in the pixel circuit to the original state.
1. An electro-optical apparatus, comprising:
a plurality of gate lines;
a plurality of data lines; and
a plurality of pixel circuits corresponding to intersections of the plurality of gate lines and the plurality of data lines,
one of the plurality of pixel circuits including a light-emitting device and a circuit, the light-emitting device having an anode and a cathode, the circuit controlling a gradation of light emitted from the light-emitting device and including a driving transistor; and
a characteristic-adjustment circuit that exchanges a source of the driving transistor with a drain of the driving transistor,
the light-emitting device being driven in a driving period including a light-emitting period and an adjusting period following the light-emitting period, and
the characteristic-adjustment circuit supplying a predetermined voltage to a gate of the driving transistor in the adjusting period.
2. An electro-optical apparatus according to claim 1 ,
each of the plurality of pixel circuits comprising a plurality of transistors, the plurality of transistors included in each pixel circuit being all n-type transistors.
3. The electro-optical apparatus according to claim 2 ,
the cathode of the light-emitting device being commonly coupled to the plurality of pixel circuits.
4. The electro-optical apparatus according to claim 2 , the characteristic-adjustment circuit switches an operation state of at least one transistor included in each pixel circuit.
5. The electro-optical apparatus according to claim 4 ,
the characteristic-adjustment circuit including a voltage clamp circuit, and the voltage clamp circuit clamping a voltage of at least one of the gate, source, or drain of the driving transistor included in each pixel circuit to the predetermined voltage.
6. The electro-optical apparatus according to claim 5 ,
each pixel circuit including an amorphous silicon transistor, and the voltage clamp circuit clamping the voltage of at least one of a gate, source, or drain of the amorphous silicon transistor to a predetermined voltage.
7. The electro-optical apparatus according to claim 4 ,
the characteristic-adjustment circuit including a voltage clamp circuit, and the voltage clamp circuit setting a voltage at a gate of the driving transistor included in the each pixel circuit to a voltage that is lower than a voltage at a source of the driving transistor.
8. An electro-optical apparatus according to claim 7 ,
each pixel circuit including an amorphous silicon transistor, and the voltage clamp circuit setting a voltage at a gate of the amorphous silicon transistor to a voltage that is lower than a voltage at a source of the amorphous silicon transistor.
9. The electro-optical apparatus according to claim 1 ,
each pixel circuit including an amorphous silicon transistor, and the characteristic-adjustment circuit exchanging a source of the amorphous silicon transistor with a drain thereof.
10. The electro-optical apparatus according to claim 1 ,
each of the plurality of pixel circuits including a current-blocking unit that blocks a current path of the light-emitting device, and each pixel circuit setting the current-blocking unit to an active state during at least part of a period during which a current is supplied to each pixel circuit through a corresponding data line.
11. The electro-optical apparatus according to claim 1 ,
each of the plurality of pixel circuits including a short-circuiting unit that connects an anode of the light-emitting device to a cathode thereof, and each pixel circuit setting the short-circuiting unit to an active state during at least part of a period during which a current is supplied to the each pixel circuit through a corresponding data line.
12. The electro-optical apparatus according to claim 1 ,
the light-emitting device being an organic electroluminescent device.
13. A method of driving an electro-optical apparatus by an active-matrix driving method, the electro-optical apparatus comprising:
a plurality of gate lines;
a plurality of data lines; and
a plurality of pixel circuits corresponding to intersections of the plurality of gate lines and the plurality of data lines,
one of the plurality of pixel circuits including a light-emitting device and a circuit, the light emitting device having an anode and a cathode, the circuit controlling a gradation of light emitted from the light-emitting device and including a driving transistor; and
a characteristic-adjustment circuit that exchanges a source of the driving transistor with a drain of the driving transistor,
the light-emitting device being driven in a driving period including a light-emitting period and an adjusting period following the light-emitting period, and
the characteristic-adjustment circuit supplying a predetermined voltage to a gate of the driving transistor in the adjusting period.
14. The method of driving an electro-optical apparatus according to claim 13 ,
the characteristic-adjustment circuit switching an operation state of at least one transistor included in the each pixel circuit.
15. The method of driving an electro-optical apparatus according to claim 14 ,
the characteristic-adjustment circuit including a voltage clamp circuit, and the voltage clamp circuit clamps the voltage of at least one of a gate, source, or drain of the driving transistor included in each pixel circuit to the predetermined voltage.
16. The method of driving an electro-optical apparatus according to claim 15 ,
each pixel circuit including an amorphous silicon transistor, and the voltage clamp circuit clamping a voltage of at least one of a gate, source, or drain of the amorphous silicon transistor to a predetermined voltage.
17. The method of driving an electro-optical apparatus according to claim 14 ,
the characteristic-adjustment circuit including a voltage clamp circuit, and the voltage clamp circuit sets a voltage at a gate of the driving transistor included in each pixel circuit to a voltage that is lower than a voltage at a source of the driving transistor.
18. The method of driving an electro-optical apparatus according to claim 17 ,
each pixel circuit including an amorphous silicon transistor, and the voltage clamp circuit setting a voltage at a gate of the amorphous silicon transistor to a voltage that is lower than a voltage at a source of the amorphous silicon transistor.
19. The method of driving an electro-optical apparatus according to claim 14 ,
each pixel circuit including an amorphous silicon transistor, and the characteristic-adjustment circuit exchanges a source of the amorphous silicon transistor with a drain thereof.
20. The method of driving an electro-optical apparatus according to claim 13 ,
each pixel circuit including a current-blocking unit that blocks a current path of the light-emitting device, and each pixel circuit setting the current-blocking unit to an active state during at least part of a period during which a current is supplied to each pixel circuit through a corresponding data line.
21. The method of driving an electro-optical apparatus according to claim 13 ,
each pixel circuit including a short-circuiting unit that connects an anode of the light-emitting device to a cathode thereof, and each pixel circuit setting the short-circuiting unit to an active state during at least part of a period during which a current is supplied to each pixel circuit through a corresponding data line.
22. An electro-optical apparatus, comprising:
a plurality of gate lines;
a plurality of data lines; and
a plurality of pixel circuits corresponding to intersections of the plurality of gate lines and the plurality of data lines,
one of the plurality of pixel circuits including a light-emitting device and a driving transistor for driving the light-emitting device, the light-emitting device having an anode and a cathode,
the driving transistor being connected to a first node and a second node,
the light-emitting device being connected to the driving transistor at one of a side of the first node and a side of the second node,
a voltage of the first node being set to a voltage higher than that of the second node during a light-emitting period that the light-emitting device emits light,
a voltage of the first node being set to a voltage lower than that of the second node during an adjusting period different from the light-emitting period, and
a predetermined voltage being supplied to a gate of the driving transistor in the adjusting period.
23. The electro-optical apparatus according to claim 22 , further comprising a characteristic-adjustment circuit that inverts a relation between the voltage of the first node and that of the second node.
24. The electro-optical apparatus according to claim 23 ,
the characteristic-adjustment circuit including a voltage clamp circuit, and the voltage clamp circuit clamping a voltage of at least one of a gate, source, or drain of the driving transistor included in each pixel circuit to the predetermined voltage.
25. The electro-optical apparatus according to claim 24 ,
the driving transistor being an amorphous silicon transistor.
26. The electro-optical apparatus according to claim 23 ,
the characteristic-adjustment circuit including a voltage clamp circuit, and the voltage clamp circuit setting a voltage at a gate of the driving transistor included in each pixel circuit to a voltage that is lower than a voltage at a source of the driving transistor.
27. The electro-optical apparatus according to claim 26 ,
the driving transistor being an amorphous silicon transistor.
28. The electro-optical apparatus according to claim 22 ,
the predetermined voltage being supplied through a switching transistor connected to the gate of the driving transistor.
29. The electro-optical apparatus according to claim 22 ,
each of the plurality of pixel circuits comprising a plurality of transistors including the driving transistor, the plurality of transistors included in each pixel circuit being all n-type transistors.
30. The electro-optical apparatus according to claim 22 ,
the cathode of the light-emitting device being commonly coupled to the plurality of pixel circuits.
31. The electro-optical apparatus according to claim 22 ,
the driving transistor being an amorphous silicon transistor.
32. The electro-optical apparatus according to claim 22 , each of the plurality of pixel circuits including a current-blocking unit that blocks a current path of the light-emitting device, and each pixel circuit setting the current-blocking unit to an active state during at least part of a period during which a current is supplied to each pixel circuit through a corresponding data line.
33. The electro-optical apparatus according to claim 22 ,
each of the plurality of pixel circuits including a short-circuiting unit that connects an anode of the light-emitting device to a cathode thereof, and each pixel circuit setting the short-circuiting unit to an active state during at least part of a period during which a current is supplied to the each pixel circuit through a corresponding data line.
34. The electro-optical apparatus according to claim 22 ,
the light-emitting device being an organic electroluminescent device.