Display unit and electronic apparatus
View Patent ↗A display unit provided with a display panel including a light emitting element and a pixel circuit for each pixel, and a drive circuit configured to drive each of the pixels. The pixel circuit includes: a first transistor configured to sample a voltage corresponding to a picture signal, the first transistor having characteristics that a parasitic capacitance at a time when the first transistor is turned off is decreased as magnitude of negative bias applied to a gate voltage is increased; a second transistor configured to control a current flowing through the light emitting element based on magnitude of the voltage sampled by the first transistor; and a retention capacitance configured to retain the voltage sampled by the first transistor.
1. A display unit provided with a display panel including a light emitting element and a pixel circuit for each pixel, and a drive circuit configured to drive each of the pixels, the pixel circuit comprising:
a first transistor configured to sample a voltage corresponding to a picture signal, the first transistor having characteristics that a parasitic capacitance at a time when the first transistor is turned off is decreased as magnitude of negative bias applied to a gate voltage is increased;
a second transistor configured to control a current flowing through the light emitting element based on magnitude of the voltage sampled by the first transistor; and
a retention capacitance configured to retain the voltage sampled by the first transistor.
2. The display unit according to claim 1 , wherein
the drive circuit applies a first voltage to a gate of the first transistor when the light emitting element is allowed to emit light, the first voltage having a negative value allowing the first transistor to be turned off.
3. The display unit according to claim 2 , wherein
the first voltage is lower than a second voltage, the second voltage being applied to the gate of the first transistor to turn off the first transistor during non-light emission of the light emitting element.
4. The display unit according to claim 2 , wherein
the drive circuit changes a voltage applied to the gate of the first transistor from the first voltage to a third voltage until the light emitting element is allowed to be turned off, the third voltage being higher than the first voltage.
5. The display unit according to claim 2 , wherein the first transistor is a top-gate type transistor including an oxide semiconductor layer.
6. The display unit according to claim 5 , wherein the first transistor has the gate at a position facing the oxide semiconductor layer, and a low-resistance source region and a low-resistance drain region that are formed in the oxide semiconductor layer by treating the oxide semiconductor layer with use of the gate as a mask.
7. An electronic apparatus provided with a display unit, the display unit including a display panel that includes a light emitting element and a pixel circuit for each pixel, and a drive circuit configured to drive each of the pixels, the pixel circuit comprising:
a first transistor configured to sample a voltage corresponding to a picture signal, the first transistor having characteristics that a parasitic capacitance at a time when the first transistor is turned off is decreased as magnitude of negative bias applied to a gate voltage is increased;
a second transistor configured to control a current flowing through the light emitting element based on magnitude of the voltage sampled by the first transistor; and
a retention capacitance configured to retain the voltage sampled by the first transistor.