[信息与通信]TFT LCD 驱动原理与系统VIP

1、tft lcd 驅動原理與系統 tft lcd 驅動原理與系統 液晶及液晶顯示器簡介 tft lcd 驅動原理 影響tft lcd 畫面品質的因素 tft lcd driver ic lcd 數位界面簡介 背光板簡介 未來趨勢與走向 被動式/主動矩陣式液晶顯示器 passive/active matrix lcd y electrode x electrode pixel the color pixel of tft lcd color filter substrate tft substrate white light color light rgb bgr clcclcclc arrang

2、ement of color filter r g b r g b r g b r g b r g b r g b grbg rbg rb rbg rb grbg r g r g gbgb r g r g gbgb r g r g w b w b r g r g w b w b stripe triangle grbg rbg rb grbg mosaic aperture ratio a-si drain electrode gate electrode insulator source electrode n+ a-si adjacent gate electrode insulator

3、(dielectric substance) display electrodes tft pixel effective area: 40.7% capacitor tft lcd 驅動 基本驅動波形 極性反轉(polarity inversion) - frame, row, column, dot 電容耦合驅動 - 二階,三階,四階 timing chart of tft lcds frame time time gate 1 2 3 n 1h tftl lcds driving method 12345 1+ 2+ 3+ 4+ 5+ 12345 1 2 3 4 5 12345 1+ 2

4、 3+ 4 5+ 12345 1 2+ 3 4+ 5 12345 1+ + + 2+ + + 3+ + + 4+ + + 5+ + + 12345 1 + + 2 + + 3 + + 4 + + 5 + + 12345 1+ + + 2 + + 3+ + + 4 + + 5+ + + 12345 1 + + 2+ + + 3 + + 4+ + + 5 + + framencolumnsframen+1columnsframencolumns framen+1columns columninversiondotinversion framencolumnsframen+1columnsframe

5、ncolumns framen+1columns frameinversion rowinversion direct driving of tft lcds dcbias ofcommon 1 frame / 1 line garyscal voltage v63 v62 . . . . . . . . v1 v0 v0 v1 . . . . . . . . v62 v63 vcom ac modulation addressing of tft lcds 1 frame / 1 line common waveform graylevel voltage v0 v0 v1 v1 v2 v2

6、 v63 v62 v62 v63 direct driving vs vcom modulation direct driving frame , row , column & pixel inversion available cancel crosstalk & remove flicker ：image quality improve power dissipation vcom modulation available frame & row inversion poor power dissipation 影響 lcd 畫面品質的因素 horizontal crosstalk ver

7、tical crosstalk shading crosstalk 液晶電容的效應 液晶電容clc會隨液晶作用電壓的改變而變化，因此在 驅動液晶時會有殘存的dc成份，其所造成的影響 image sticking. picture flicker. 液晶作用電壓大時，液晶分子趨向平行電場方向排列 液晶作用電場小時，液晶分子趨向垂直電場方向排列 vp = vgd vgd cgd vghl cgd + cs + c cgd vghl cgd + cs + c horizontal line crosstalk rgb cs c cs c cs c color filter substrate ba

8、signal of a line signal of b line common waveform difference of effective voltage in b line black level gray level gray level horizontal area crosstalk ba signal of a line signal of b line common waveform v15m) data-to-data skew tolerance 1 clock cycle tmds tmds (transition minimized differential si

9、gnaling)is an interface standard based on panellink technology developed by silicon image, inc. swing control encoder/ serialized pll graphic controller termination control recovery/ decorder/ desirializer pll lcd panel datadata dede controlscontrols clockclock tx1(green) tx0(blue) tx2(red) clock 24

10、 5 24/36 5 vcc vcc parallel data (cmos) parallel data (cmos) tmdsi/f hostmonitor block diagram of tnds dvi dvi (digital visual interface) promoted by ddwg intel, ibm, hp, compaq, nec, fujitsu, silicon image dual channel tmds support vga to qxga pixel clock：25mhz 330mhz dvi dvi:molex 24 + 5 pin conne

11、ctor pin assignment pinsignal assignmentpinsignal assignmentpinsignal assignment 1tmds data2-9tmds data1-17tmds data0- 2tmds data2+10tmds data1+18tmds data0+ 3tmds data2/4 shield 11tmds data1/3 shield19tmds data0/5 shield 4tmds data4-12tmds data3-20tmds data5- 5tmds data4+13tmds data3+21tmds data5+

12、6ddc clock14+5v power22tmds clock shield 7ddc data15ground(return for +5v,hsync,and vsync) 23tmds clock+ 8analog vertical sync16hot plug detect24tmds clock- c1analog redc2analog greenc3analog blue c4analog horizontal hync c5analog ground (analog r,g,&breturn) pin 1 pin 24 pin 8 pin 17 c1 c2 c4 gvif gvif(gigabit video interface) promoted by sony allows using small connector and long cable(10m) only one pair differential signal used support 24bit/pixel, xga pixel clock：25mhz 65mhz 400mv voltage swing dc balancing using 2pair, s