Image sticking(I.S.) is a main factor that lowers the display quality in TFT-LCD

and it is also the most complicated issue that occurred on LC display. In this study

measuring method of I.S. level is proposed

and experiments are performed to find the relationship between image sticking and TFT transfer curve. The feature of AC image sticking is discovered

and the mechanism of the image sticking is obtained. By analyzing the luminance and TFT

I

off

(Leakage current at TFT off state) on white(W) and black(B) area at chessboard image and comparing the simulation results

we find that the recharging difference of pixels on W and B area

which can be result in different pixel holding voltage(△

V

>

12.5 mV)

is responsible for image sticking. Based on this mechanism

we introduced two methods to improve image sticking. One way is to lower the TFT

I

off

(

<

50 pA)and stabilize the TFT character during a-Si formation process

which can effectively decrease the shift of TFT transfer curve during the I.S. image aging. Another way is to adjust the gate low voltage(VGL)to a proper value that can deviate from the peak of △

I

off

curve of W and B area. This two methods is proved to solve the AC image sticking effectively(△

L

<

0.5 cd/m

2

).