Electro-optical device, driving method for electro-optical device, and electronic apparatus
A pixel circuit provided corresponding to a scanning line and a data line includes a transistor and an OLED that is an example of a light emitting element. In a compensation period, a gate node and a drain node of the transistor are electrically coupled, and the gate node of the transistor has a voltage corresponding to a threshold voltage. In a writing period, the gate node of the transistor is changed from the voltage corresponding to the threshold voltage by a voltage corresponding to luminance of the light emitting element, and in a discharge period, a reset voltage is applied to a drain node of the transistor via a data line.
1. An electro-optical device, comprising:
a pixel circuit provided corresponding to a scanning line and a data line; and
a first transistor and a light emitting element included in the pixel circuit, wherein
the first transistor is configured to supply a current corresponding to a voltage between a gate node of the first transistor and a source node of the first transistor to the light emitting element,
a horizontal scanning period includes a compensation period, a writing period, and a discharge period in this order,
in the compensation period, the gate node of the first transistor and a drain node of the first transistor are electrically coupled, and a voltage of the gate node of the first transistor is set to a voltage corresponding to a threshold voltage of the first transistor,
in the writing period, the voltage of the gate node of the first transistor is changed from the voltage corresponding to the threshold voltage by a voltage corresponding to luminance of the light emitting element,
in the discharge period, a reset voltage is applied to the drain node of the first transistor via the data line, and
in a light emission period after the discharge period, the first transistor supplies a current corresponding to the voltage between the gate node of the first transistor and the source node of the first transistor to the light emitting element.
2. The electro-optical device according to claim 1 , wherein the pixel circuit includes a second transistor, a third transistor, and a fourth transistor,
the second transistor is provided between the data line and the gate node of the first transistor and is in an ON state or an OFF state in accordance with a voltage of the scanning line,
the third transistor is provided between the data line and the drain node of the first transistor,
the fourth transistor is provided between the drain node of the first transistor and the light emitting element,
in the compensation period, the second transistor and the third transistor are in the ON state,
in the writing period, the second transistor is in the ON state, and the third transistor is in the OFF state,
in the discharge period, the second transistor is in the OFF state, and the third transistor is in the ON state, and
in the light emission period, the second transistor and the third transistor are in the OFF state, and the fourth transistor is in the ON state.
3. The electro-optical device according to claim 1 , wherein the pixel circuit includes a second transistor, a third transistor, a fourth transistor, and a fifth transistor,
the second transistor is provided between the data line and the gate node of the first transistor and is in an ON state or an OFF state in accordance with a voltage of the scanning line,
the third transistor is provided between the data line and the drain node of the first transistor,
the fourth transistor is provided between the drain node of the first transistor and the light emitting element,
the fifth transistor is provided between one end of the light emitting element and a feed line that supplies the reset voltage,
in the compensation period, the second transistor and the third transistor are in the ON state,
in the writing period, the second transistor is in the ON state, and the third transistor is in the OFF state,
in the discharge period, the second transistor is in the OFF state, and the third transistor is in the ON state,
in the light emission period, the second transistor and the third transistor are in the OFF state, and the fourth transistor is in the ON state, and
in a period before the light emission period, the fifth transistor is in the ON state.
4. The electro-optical device according to claim 1 , wherein
the reset voltage is 0 volt to 1 volt.
5. The electro-optical device according to claim 1 , comprising a sixth transistor between the data line and a feed line that supplies the reset voltage, wherein,
in plan view, the sixth transistor is disposed outside a display region in which the light emitting element is provided.
6. The electro-optical device according to claim 5 , wherein
the sixth transistor is an N-channel type.
7. An electronic apparatus comprising the electro-optical device according to claim 1 .
8. A method for driving an electro-optical device including a pixel circuit provided corresponding to a scanning line and a data line, and a transistor and a light emitting element included in the pixel circuit,
wherein the transistor is configured to supply a current corresponding to a voltage between a gate node of the transistor and a source node of the transistor to the light emitting element, and
wherein a horizontal scanning period includes a compensation period, a writing period, and a discharge period in this order,
in the compensation period, the gate node of the transistor and a drain node of the transistor are electrically coupled, and a voltage of the gate node of the transistor is set to a voltage corresponding to a threshold voltage of the transistor,
in the writing period, the voltage of the gate node of the transistor is changed from the voltage corresponding to the threshold voltage by a voltage corresponding to luminance of the light emitting element,
in the discharge period, a reset voltage is applied to the drain node of the transistor via the data line, and
in a light emission period after the discharge period, the transistor supplies the current corresponding to the voltage between the gate node of the transistor and the source node of the transistor to the light emitting element.