Display device and dimming method thereof

Abstract

The embodiment of the invention provides a display device and a dimming method thereof. The display device comprises a light emitting diode and a driving module, wherein the driving module is used for driving the light emitting diode; the driving module comprises a first switch circuit, a second switch circuit and a driving transistor; the first switch circuit is used for selectively writing gray scale voltage into a first capacitor; the second switch circuit is used for selectively writing compensation voltage into a second capacitor; the driving transistor is respectively coupled with the light emitting diode, the first capacitor and the second capacitor; the driving transistor is controlled by the gray scale voltage and the compensation voltage so as to adjust driving current output to the light emitting diode; the gray scale voltage is used for adjusting the voltage difference of the grid and the source of the driving transistor; the compensation voltage is used for adjusting critical voltage of the driving transistor.

Description

technical field [0001] The invention relates to a display device and a dimming method thereof, in particular to a display device capable of changing the critical voltage of a driving transistor and a dimming method thereof. Background technique [0002] With the popularization of various audio-visual media equipment such as computers, mobile phones, and televisions, display devices for presenting images are more and more widely used in production and life. In general organic light emitting diode (Organic Light Emission Diode, OLED) display devices, multiple transistors are used to control and drive the light emitting diodes, so that each light emitting diode can emit proper brightness. [0003] for example, figure 1 A schematic circuit diagram of a prior art OLED display device is shown. Such as figure 1 As shown, the display device 9 has a switching transistor 90 , a capacitor 92 , a driving transistor 94 and a light emitting diode 96 . The switch transistor 90 is contr...

AI Technical Summary

Problems solved by technology

However, there are errors in the semiconductor characteristics (such as threshold voltage) of different transistors when they leave the factory. Although the same grayscale voltage can be provided to the driving transistor 94, the driving current used by the driving transistor 94 to drive the light-emitting diode 96 will not be completely same

[0004] From the perspective of the display screen, the difference in driving current will make the brightness distribution of the screen uneven (mura effect), which will affect the viewing quality of the user

In order to deal with the uneven brightness distribution of the screen, it is necessary to increase the circuit structure in each pixel group to compensate for the difference in driving current, but the additional circuit structure will lead to a decrease in the pixel aperture ratio

Images