《LCD驱动原理介绍》PPT课件.ppt

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1、 LCD設計處製程組設計處製程組 LCD Design Dept.Process Control Sec.Ext:2897-2898crosstalkCrosstalk is the different visible contrast of the OFF segmentsCrosstalk appears when the electro-optical state of individual pixels are affected by the electro-optical states of other pixels 10/25/20221 LCD設計處製程組設計處製程組 LCD D

2、esign Dept.Process Control Sec.Ext:2897-2898crosstalkCrosstalk effects are correlated to the nonideal display components:the nonzero sheet resistance of the ITO-electrodesthe output impedance of the row and column driversacting in combination with the pixel capacitance entails a distortion of the ad

3、dressing waveform10/25/20222 LCD設計處製程組設計處製程組 LCD Design Dept.Process Control Sec.Ext:2897-2898crosstalkmin.frequencyhorizontal crosstalkVertical+horizontal crosstalkmax.frequency10/25/20223 LCD設計處製程組設計處製程組 LCD Design Dept.Process Control Sec.Ext:2897-2898crosstalkColumn all off or onColumn checkerbo

4、ard 10/25/20224 LCD設計處製程組設計處製程組 LCD Design Dept.Process Control Sec.Ext:2897-2898Crosstalkvertical crosstalkVertical crosstalk(ghosting)is generated by the nonideal frequency response of the LCD and the image dependent frequency content of the column signal at low frequencies the necessary voltage t

5、o achieve a 50%transmission(V50)decrease attributed to ionic effects in the LC layer the effective pixel voltage becomes high because the waveform is changed only slightly and the waveform distortion is small the pixel is dark crosstalk10/25/20225 LCD設計處製程組設計處製程組 LCD Design Dept.Process Control Sec.

6、Ext:2897-2898Crosstalkvertical crosstalkVertical crosstalk(ghosting)is generated by the nonideal frequency response of the LCD and the image dependent frequency content of the column signal at high frequencies the necessary V50 increases due to the low-pass filtering of the panel,caused by the ITO s

7、heet resistance and the capacitance ofthe pixel and the frequence dependency of the effective pixel voltage becomes low because distorsion occurs in the column output waveform due to the driver and/or panel impedance the pixel is bright10/25/20226 LCD設計處製程組設計處製程組 LCD Design Dept.Process Control Sec.

8、Ext:2897-2898Reduction of Crosstalkhomogenize the frequency content of the column waveform improved driving schemes-IAP-MLA pattern dependent correction of the output voltage of the driver reduce space charge density reduce RC product of the whole panel(cell gap )low dV/df of the LC mixture sufficie

9、nt e-o curve and selection of an optimum Vop10/25/20227 LCD設計處製程組設計處製程組 LCD Design Dept.Process Control Sec.Ext:2897-2898STN 面板之面板之dv/df特性特性10/25/20228 LCD設計處製程組設計處製程組 LCD Design Dept.Process Control Sec.Ext:2897-2898Whats M signal(no M)Checkerboard waveformAll on/off waveform10/25/20229 LCD設計處製程組設計

10、處製程組 LCD Design Dept.Process Control Sec.Ext:2897-2898Whats M signal(M=1)在驅動波形中每(M+1)M+1)次就變換一次極性Checkerboard waveformAll on/off waveform10/25/202210 LCD設計處製程組設計處製程組 LCD Design Dept.Process Control Sec.Ext:2897-2898Whats M signal(032)032無設定M signal時COM waveform032設定M=6al時COM waveform10/25/202211 LCD

11、設計處製程組設計處製程組 LCD Design Dept.Process Control Sec.Ext:2897-2898Whats M signal(032)032無設定M signal時A點合成waveform032無設定M signal時B點合成waveform10/25/202212 LCD設計處製程組設計處製程組 LCD Design Dept.Process Control Sec.Ext:2897-2898Whats M signal(032)032設定M=6時A點合成waveform032設定M=6時B點合成waveform10/25/202213 LCD設計處製程組設計處製程組 LCD Design Dept.Process Control Sec.Ext:2897-2898Whats M signalvHow to How to calcultecalculte M frequency?M frequency?當無設定M signal時,M frequency=frame/2=70/2=35Hz當M signal=m時,M frequency=N/(m+1)x(frame/2)=N/(m+1)x35 N=duty=COM數10/25/202214