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US 8,913,090 B2Granted
Pixel circuit, organic electro-luminescent display apparatus, and method of driving the same
AssigneeSamsung Display Co., Ltd.
InventorsBo-Yong Chung, Yong-Sung Park
Life of this patent
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Abstract
A pixel circuit includes a light emitting device, an N-type driving transistor for outputting a driving current according to a voltage applied to the gate electrode, a first capacitor coupled to a gate electrode of the driving transistor, a second capacitor including a first terminal coupled to the gate electrode of the driving transistor and a second terminal coupled to the first electrode of the light emitting device, and second through sixth N-type transistors. An initialization period is reduced for a driving operation and the threshold voltage compensation time of a driving transistor is controlled.
Claims21
A pixel circuit comprising:
- a light emitting device comprising a first electrode and a second electrode;
- a driving transistor comprising:
- a first electrode;
- a second electrode;
- and a gate electrode, the driving transistor for outputting a driving current according to a voltage applied to the gate electrode of the driving transistor;
- a first capacitor comprising a first terminal and a second terminal, the second terminal of the first capacitor being coupled to the gate electrode of the driving transistor;
- a second capacitor comprising a first terminal coupled to the gate electrode of the driving transistor and a second terminal directly coupled to the first electrode of the light emitting device, the second capacitor being different from the first capacitor;
- a second transistor comprising:
- a first electrode coupled to the gate electrode of the driving transistor;
- a second electrode coupled to the first electrode of the driving transistor;
- and a gate electrode, wherein the second transistor is configured to be turned on in response to a second scan signal applied to the gate electrode;
- a third transistor for applying a first power supply voltage to the first electrode of the driving transistor in response to an emission control signal, the third transistor comprising a first electrode directly connected to a first power supply voltage line;
- a fourth transistor comprising a first electrode for receiving a data signal and a second electrode coupled to the first terminal of the first capacitor, wherein the fourth transistor is configured to be turned on in response to a third scan signal applied to the gate electrode;
- a fifth transistor comprising:
- a first electrode directly connected to a reference voltage line for receiving a reference voltage;
- a second electrode coupled to the first terminal of the first capacitor;
- and a gate electrode, wherein the fifth transistor is configured to be turned on in response to the second scan signal applied to the gate electrode;
- and
- a sixth transistor comprising:
- a first electrode for receiving a first voltage;
- a second electrode directly electrically connected to the gate electrode of the driving transistor;
- and a gate electrode, wherein the sixth transistor is configured to be turned on in response to a first scan signal applied to the gate electrode,
- wherein the driving transistor and the second to sixth transistors are N-type transistors, and
- wherein the second electrode of the driving transistor is directly connected to the light emitting device.
21 more elements
An organic electro-luminescent display apparatus comprising:
- a scan driver for supplying a scan signal to a plurality of scan lines;
- an emission control driver for supplying an emission control signal to a plurality of emission control lines;
- a data driver for supplying a data signal to a plurality of data lines;
- and
- a plurality of pixel circuits located at crossing regions of the scan lines, the emission control lines and the data lines, wherein each pixel circuit of the plurality of pixel circuits comprises:
- an organic light emitting diode (OLED) comprising a first electrode and a second electrode;
- a driving transistor comprising:
- a first electrode;
- a second electrode;
- and a gate electrode, the driving transistor for outputting a driving current according to a voltage applied to the gate electrode of the driving transistor;
- a first capacitor comprising a first terminal and a second terminal coupled to the gate electrode of the driving transistor;
- a second capacitor comprising a first terminal coupled to the gate electrode of the driving transistor and a second terminal directly coupled to the first electrode of the OLED, the second capacitor being different from the first capacitor;
- a second transistor comprising:
- a first electrode coupled to the gate electrode of the driving transistor;
- a second electrode coupled to the first electrode of the driving transistor;
- and a gate electrode, wherein the second transistor is configured to be turned on in response to a second scan signal applied to the gate electrode;
- a third transistor for applying a first power supply voltage to the first electrode of the driving transistor in response to the emission control signal, the third transistor comprising a first electrode directly connected to a first power supply voltage line;
- a fourth transistor comprising:
- a first electrode coupled to the data signal, a second electrode coupled to the first terminal of the first capacitor;
- and a gate electrode, wherein the fourth transistor is configured to be turned on in response to a third scan signal applied to the gate electrode;
- a fifth transistor comprising:
- a first electrode directly connected to a reference voltage line coupled to a reference voltage;
- a second electrode coupled to the first terminal of the first capacitor;
- and a gate electrode, wherein the fifth transistor is configured to be turned on in response to the second scan signal applied to the gate electrode;
- and
- a sixth transistor comprising:
- a first electrode coupled to the first power supply voltage;
- a second electrode directly electrically connected to the gate electrode of the driving transistor;
- and a gate electrode, wherein the sixth transistor is configured to be turned on in response to a first scan signal applied to the gate electrode,
- wherein the driving transistor and the second to sixth transistors are N-type transistors, and
- wherein the second electrode of the driving transistor is directly connected to the light emitting device.
28 more elements
Dependencies are inferred from the claim text.