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Pixel driving circuit and driving method thereof, and display device

A pixel drive circuit and drive tube technology, applied in static indicators, instruments, etc., can solve the problems of transistor threshold voltage difference, shortened service life, inconsistency of drive current, etc., to improve the uniformity of brightness and remove aging factors , the effect of prolonging the service life

Inactive Publication Date: 2015-11-18
BOE TECH GRP CO LTD +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] Regardless of whether it is a low-temperature polysilicon transistor LTPS-TFT or an oxide transistor Oxide-TFT, due to the inhomogeneity of the manufacturing process, the threshold voltage of the transistor at different positions will be different, which is very important for current-driven devices (such as OLED light-emitting elements). It is very fatal for the driving consistency of the system, because when the same gray scale voltage is input, the threshold voltages of different driving tubes are different, and different threshold voltages will generate different driving currents, resulting in inconsistency of driving currents
Therefore, the traditional OLED drive circuit needs to compensate the threshold voltage of the drive tube, so that the drive current is no longer affected by the inconsistency of the threshold voltage of the drive tube.
[0004] At the same time, with the prolongation of the use time of the OLED light-emitting element, a lot of unrecombined carriers will accumulate at the internal interface of the light-emitting layer of the OLED light-emitting element. The formation of carriers will cause a built-in electric field to form inside the OLED light-emitting element, causing the OLED to emit light. The threshold voltage of the element is constantly increasing, and the continuous increase of the threshold voltage of the OLED light-emitting element will directly lead to the aging of its luminescent material and shorten the service life
[0005] At present, at least seven transistors are required in the traditional OLED drive circuit to simultaneously realize the compensation of the threshold voltage of the drive tube and alleviate the aging of the OLED luminescent material, which limits the resolution of the OLED display to a certain extent.

Method used

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

Examples

Experimental program
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Embodiment 1

[0070] This embodiment provides a pixel driving circuit, such as figure 1 As shown, it is used to drive the light-emitting element OLED, including: signal line data, control line, driving unit 3, power supply unit, compensation unit 1, light-emitting control unit 4, data writing unit 5, storage unit 6 and aging mitigation unit 2; the power supply unit is used to provide a power supply signal for the pixel drive circuit, and the drive unit 3 is used to drive the light-emitting element OLED; the signal line data is used to provide a data signal for the data writing unit 5; the control line is used for the compensation unit 1, The light-emitting control unit 4, the data writing unit 5 and the aging mitigation unit 2 provide control signals; the light-emitting control unit 4 is used to control the light-emitting element OLED to emit light; the data writing unit 5 is used to write the data signal into the storage unit 6; the storage unit 6 Used to store the data signal voltage writ...

Embodiment 2

[0096] This embodiment provides a pixel driving circuit, which is different from the pixel driving circuit in Embodiment 1, such as Figure 8 As shown, the control lines include scanning control lines G(n), compensation control lines C(n) and light emission control lines EM(n); the power supply unit includes a first power supply terminal ELVDD and a second power supply terminal ELVSS; the drive unit 3 includes a drive The compensation unit 1 includes a fourth switch tube T4; the light emission control unit 4 includes a first switch tube T1 and a third switch tube T3; the data writing unit 5 includes a second switch tube T2; the storage unit 6 includes a capacitor Cst. The gate of the first switching transistor T1 is connected to the light emission control line EM(n), the first pole of the first switching transistor T1 is connected to the first power supply terminal ELVDD, and the second pole of the first switching transistor T1 is connected to the second pole of the capacitor C...

Embodiment 3

[0117] This embodiment provides a display device, which includes a light-emitting element, and further includes the pixel driving circuit in any one of Embodiments 1-2, where the pixel driving circuit is connected to the light-emitting element for driving the light-emitting element.

[0118] Wherein, the light-emitting element adopts an organic electroluminescent diode.

[0119] By adopting the pixel driving circuit in any one of Embodiments 1-2, the driving current of the pixels in the display device during the driving process can tend to be consistent, thereby improving the uniformity of the brightness of the display device when displaying; at the same time, it also The service life of the display device can be extended.

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Abstract

The invention provides a pixel driving circuit and a driving method thereof, and a display device. The pixel driving circuit comprises a signal line, a control line, a driving unit, a power unit, a compensation unit, a light emitting control unit, a data writing unit, a storage unit, and an aging alleviation unit. The driving unit is used to drive a light emitting element. The light emitting control unit is used to control light emitting of the light emitting element. The data writing unit is used to write data signals into the storage unit. The compensation unit is used to compensate the threshold voltage of the driving unit. The aging alleviation unit is used to short-circuit the cathode and the anode of the light emitting element. By adopting the pixel driving circuit, the threshold voltage of the driving unit can be compensated to make the driving current of the driving unit consistent and improve the uniformity of brightness of the light emitting element, and the cathode and the anode of the light emitting element can be short-circuited to eliminate uncompounded carriers on the interface of a light emitting layer, remove factors causing aging of light emitting materials and prolong the service life of light emitting materials.

Description

technical field [0001] The present invention relates to the field of display technology, in particular, to a pixel driving circuit, a driving method thereof, and a display device. Background technique [0002] Organic light-emitting diode display OLED (organic light emitting diode) can emit light is driven by the current generated by the drive tube TFT in a saturated state, that is, current-driven light emission. [0003] Regardless of whether it is a low-temperature polysilicon transistor LTPS-TFT or an oxide transistor Oxide-TFT, due to the inhomogeneity of the manufacturing process, the threshold voltage of the transistor at different positions will be different, which is very important for current-driven devices (such as OLED light-emitting elements). It is very fatal for the drive consistency of the system, because when the same gray scale voltage is input, the threshold voltages of different drive tubes are different, and different threshold voltages will generate diff...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G09G3/32
CPCG09G3/3233G09G2300/0861G09G2310/0262G09G2320/043G09G2320/0693G09G2320/0233G09G2320/045G09G2330/02
Inventor 青海刚祁小敬
Owner BOE TECH GRP CO LTD