Pixel circuit of active organic electroluminescent display and programming method of pixel circuit

Abstract

The invention discloses a pixel circuit of an active organic electroluminescent display. The pixel circuit comprises a first transistor, a second transistor, a third transistor, a fourth transistor, a fifth transistor, an organic lighting emitting diode, a first capacitor and a second capacitor. The invention further discloses a programming method of the pixel circuit of the active organic electroluminescent display. The programming method includes that in the first frame period, programming includes stages of initializing, threshold voltage latch, data loading and lighting of the organic light emitting diode; in continuous N frame periods from the second frame, programming only includes stages of data loading and lighting of the organic light emitting diode; and repeating the above process consecutively and circularly. In case of threshold voltage drift of the driving transistor and ageing of the organic light emitting diode, current of the organic light emitting diode is always kept constant, and programming speed of the pixel circuit is effectively increased.

Description

technical field

[0001] The invention relates to a pixel driving technology of an active organic electroluminescent display, in particular to a pixel circuit of an active organic electroluminescent display and a programming method thereof. Background technique

[0002] Active Matrix Organic Light Emitting Diode (AMOLED) is an all-solid-state process, which has the advantages of small size, large information display, self-illumination, large viewing angle, short response time, and low power consumption. Research hotspots in academia and industry. Thin Film Transistors (Thin Film Transistors: TFT) backplane technology is a core technology of AMOLED. Currently, TFTs (thin film transistors) that can be applied to active OLEDs (organic light-emitting diodes) mainly include amorphous silicon TFTs (a-Si TFTs), polysilicon TFTs (poly-Si TFTs) and ZnO-based TFTs.

[0003] OLED devices are current-driven and require a stable current to control light emission, which is different from ...

Examples

Embodiment 1

[0036] Such as figure 1 As shown, the pixel circuit of the active organic electroluminescent display in this embodiment includes a first transistor T1, a second transistor T2, a third transistor T3, a fourth transistor T4, a fifth transistor T5, an organic light emitting diode OLED, a A capacitor C1 and a second capacitor C2.

[0037] Each transistor includes a gate, drain and source.

[0038] The drain of the first transistor is connected to the data line, and the source of the first transistor is connected to the first plate of the first capacitor ( figure 1 Point C is a point between the source of the first transistor and the first plate of the first capacitor), and the gate of the first transistor is connected to the first scanning control line V1.

[0039] The drain of the second transistor is connected to the initial voltage line Vinit, the source of the second transistor is connected to the second plate of the first capacitor, and the gate of the second transistor is co...

Embodiment 2

[0063] Such as image 3 As shown, the pixel circuit of the active organic electroluminescent display of this embodiment is the same as that of Embodiment 1 except for the following features:

[0064] In Embodiment 1, "the second plate of the first capacitor is grounded through the second capacitor" is replaced with "the first plate of the first capacitor is grounded through the second capacitor".

[0065] The programming method of the pixel circuit of the active organic electroluminescence display of the present embodiment:

[0066] For the first frame period, the programming steps are as follows:

[0067] S11 initialization: control the gate voltage V1 of the first transistor, the gate voltage V2 of the second transistor to be high level, the gate voltage V3 of the third transistor, and the gate voltage V4 of the fourth transistor to be low level, and the data line Voltage V data is zero level, the value of the initial voltage Vinit is greater than the threshold voltage of...

technical field

[0001] The invention relates to a pixel driving technology of an active organic electroluminescent display, in particular to a pixel circuit of an active organic electroluminescent display and a programming method thereof. Background technique

[0002] Active Matrix Organic Light Emitting Diode (AMOLED) is an all-solid-state process, which has the advantages of small size, large information display, self-illumination, large viewing angle, short response time, and low power consumption. Research hotspots in academia and industry. Thin Film Transistors (Thin Film Transistors: TFT) backplane technology is a core technology of AMOLED. Currently, TFTs (thin film transistors) that can be applied to active OLEDs (organic light-emitting diodes) mainly include amorphous silicon TFTs (a-Si TFTs), polysilicon TFTs (poly-Si TFTs) and ZnO-based TFTs.

[0003] OLED devices are current-driven and require a stable current to control light emission, which is different from ...

Examples

Embodiment 1

[0036] Such as figure 1 As shown, the pixel circuit of the active organic electroluminescent display in this embodiment includes a first transistor T1, a second transistor T2, a third transistor T3, a fourth transistor T4, a fifth transistor T5, an organic light emitting diode OLED, a A capacitor C1 and a second capacitor C2.

[0037] Each transistor includes a gate, drain and source.

[0038] The drain of the first transistor is connected to the data line, and the source of the first transistor is connected to the first plate of the first capacitor ( figure 1 Point C is a point between the source of the first transistor and the first plate of the first capacitor), and the gate of the first transistor is connected to the first scanning control line V1.

[0039] The drain of the second transistor is connected to the initial voltage line Vinit, the source of the second transistor is connected to the second plate of the first capacitor, and the gate of the second transistor is co...

Embodiment 2

[0063] Such as image 3 As shown, the pixel circuit of the active organic electroluminescent display of this embodiment is the same as that of Embodiment 1 except for the following features:

[0064] In Embodiment 1, "the second plate of the first capacitor is grounded through the second capacitor" is replaced with "the first plate of the first capacitor is grounded through the second capacitor".

[0065] The programming method of the pixel circuit of the active organic electroluminescence display of the present embodiment:

[0066] For the first frame period, the programming steps are as follows:

[0067] S11 initialization: control the gate voltage V1 of the first transistor, the gate voltage V2 of the second transistor to be high level, the gate voltage V3 of the third transistor, and the gate voltage V4 of the fourth transistor to be low level, and the data line Voltage V data is zero level, the value of the initial voltage Vinit is greater than the threshold voltage of...

Images