Pixel circuit and driving method thereof, display panel and display device

Abstract

The invention belonging to the technical field of displaying discloses a pixel circuit and a driving method thereof, a display panel and a display device. The pixel circuit comprises a driving transistor with a double-gate structure, a first switching transistor, a second switching transistor, a third switching transistor, a fourth switching transistor, a first capacitor, a second capacitor and a light-emitting device. All the transistors and the capacitors cooperate with each other to compensate a threshold voltage of the driving transistor, so that the driving current for driving the light-emitting device to emit light is only associated with a voltage of a data signal and thus the influence on the light-emitting device by the threshold of a driving control module is eliminated. When different pixel units are loaded by using a same data signal, images with the same brightness are obtained, so that uniformity of image brightness of a display region of a display device is improved and the difficulty of gamma voltage adjusting by the pixel circuit is reduced. Moreover, the selection range of the data signal is further optimized, so that energy consumption is reduced.

Description

technical field

[0001] The invention relates to the field of display technology, in particular to a pixel circuit, a driving method thereof, a display panel and a display device. Background technique

[0002] Organic Light Emitting Diode (OLED) is one of the hot spots in the field of display research today. Compared with Liquid Crystal Display (LCD), OLED has low energy consumption, low production cost, self-illumination, wide viewing angle and response At present, OLED displays have begun to replace traditional LCD displays in display fields such as mobile phones, PDAs, and digital cameras. Among them, pixel circuit design is the core technical content of OLED display, which has important research significance.

[0003] Unlike LCD, which uses a stable voltage to control brightness, OLED is current-driven and requires a stable current to control light emission. Due to the process and device aging, there will be non-uniformity in the threshold voltage Vth of the driving tra...

Examples

Embodiment 1

[0083] Optionally, with image 3 The structure of the pixel circuit shown is taken as an example to illustrate, and the corresponding input and output timing diagram is as follows Figure 9 as shown, Figure 9 for image 3 The structure shown corresponds to a timing diagram. Specifically, the main selection of Figure 9 There are four stages in the shown input-output timing diagram: the node initialization stage P1, the threshold detection stage P2, the data writing stage P3 and the lighting stage P4.

[0084] In the node initialization phase P1, EMIT=0, Scan1=1, Scan2=1.

[0085] Since Scan1=1, the second switch transistor T2 is turned on to provide the reference signal V1 sent by the data signal terminal data to the first node N1, and the potential of the first node N1 is V1; the third switch transistor T3 is turned on to connect the reference signal V1 to the first node N1. The reference signal V1 sent by the signal terminal Vref is provided to the third node N3, and t...

Embodiment 2

[0093] Optionally, with image 3 The structure of the pixel circuit shown is taken as an example to illustrate, and the corresponding input and output timing diagram is as follows Figure 10 as shown, Figure 10 for image 3 Another timing diagram corresponding to the structure shown. Specifically, the main selection of Figure 10 There are five stages in the shown input-output timing diagram: the node initialization stage P1, the holding stage P5, the threshold detection stage P2, the data writing stage P3 and the light emitting stage P4. Wherein, the timing is applicable to include a row of zeroth row of pixels before the first row of pixels, and it is stipulated that the extending direction of the gate lines is the row direction. During the scanning process of each row of pixel circuits, the node initialization phase P1 and the holding phase P5 of the next row of pixels are carried out simultaneously with the threshold detection phase P2 and data writing phase P3 of the...

Embodiment 3

[0105] Optionally, with Figure 5 The structure of the pixel circuit shown is taken as an example to illustrate, and the corresponding input and output timing diagram is as follows Figure 9 as shown, Figure 9 for Figure 5 The structure shown corresponds to a timing diagram. Specifically, the main selection of Figure 9 There are four stages in the shown input-output timing diagram: the node initialization stage P1, the threshold detection stage P2, the data writing stage P3 and the lighting stage P4.

[0106] In the node initialization phase P1, EMIT=0, Scan1=1, Scan2=1.

[0107] Since Scan1=1, the second switch transistor T2 is turned on to provide the reference signal V1 sent by the data signal terminal data to the first node N1, and the potential of the first node N1 is V1; the third switch transistor T3 is turned on to connect the reference signal V1 to the first node N1. The reference signal V1 sent by the signal terminal Vref is provided to the third node N3, and...

technical field

[0001] The invention relates to the field of display technology, in particular to a pixel circuit, a driving method thereof, a display panel and a display device. Background technique

[0002] Organic Light Emitting Diode (OLED) is one of the hot spots in the field of display research today. Compared with Liquid Crystal Display (LCD), OLED has low energy consumption, low production cost, self-illumination, wide viewing angle and response At present, OLED displays have begun to replace traditional LCD displays in display fields such as mobile phones, PDAs, and digital cameras. Among them, pixel circuit design is the core technical content of OLED display, which has important research significance.

[0003] Unlike LCD, which uses a stable voltage to control brightness, OLED is current-driven and requires a stable current to control light emission. Due to the process and device aging, there will be non-uniformity in the threshold voltage Vth of the driving tra...

Examples

Embodiment 1

[0083] Optionally, with image 3 The structure of the pixel circuit shown is taken as an example to illustrate, and the corresponding input and output timing diagram is as follows Figure 9 as shown, Figure 9 for image 3 The structure shown corresponds to a timing diagram. Specifically, the main selection of Figure 9 There are four stages in the shown input-output timing diagram: the node initialization stage P1, the threshold detection stage P2, the data writing stage P3 and the lighting stage P4.

[0084] In the node initialization phase P1, EMIT=0, Scan1=1, Scan2=1.

[0085] Since Scan1=1, the second switch transistor T2 is turned on to provide the reference signal V1 sent by the data signal terminal data to the first node N1, and the potential of the first node N1 is V1; the third switch transistor T3 is turned on to connect the reference signal V1 to the first node N1. The reference signal V1 sent by the signal terminal Vref is provided to the third node N3, and t...

Embodiment 2

[0093] Optionally, with image 3 The structure of the pixel circuit shown is taken as an example to illustrate, and the corresponding input and output timing diagram is as follows Figure 10 as shown, Figure 10 for image 3 Another timing diagram corresponding to the structure shown. Specifically, the main selection of Figure 10 There are five stages in the shown input-output timing diagram: the node initialization stage P1, the holding stage P5, the threshold detection stage P2, the data writing stage P3 and the light emitting stage P4. Wherein, the timing is applicable to include a row of zeroth row of pixels before the first row of pixels, and it is stipulated that the extending direction of the gate lines is the row direction. During the scanning process of each row of pixel circuits, the node initialization phase P1 and the holding phase P5 of the next row of pixels are carried out simultaneously with the threshold detection phase P2 and data writing phase P3 of the...

Embodiment 3

[0105] Optionally, with Figure 5 The structure of the pixel circuit shown is taken as an example to illustrate, and the corresponding input and output timing diagram is as follows Figure 9 as shown, Figure 9 for Figure 5 The structure shown corresponds to a timing diagram. Specifically, the main selection of Figure 9 There are four stages in the shown input-output timing diagram: the node initialization stage P1, the threshold detection stage P2, the data writing stage P3 and the lighting stage P4.

[0106] In the node initialization phase P1, EMIT=0, Scan1=1, Scan2=1.

[0107] Since Scan1=1, the second switch transistor T2 is turned on to provide the reference signal V1 sent by the data signal terminal data to the first node N1, and the potential of the first node N1 is V1; the third switch transistor T3 is turned on to connect the reference signal V1 to the first node N1. The reference signal V1 sent by the signal terminal Vref is provided to the third node N3, and...

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