小尺寸液晶顯示器閃動現象之改善

Abstract

小尺寸液晶顯示器的應用非常廣泛，如手機、MP3 Player及數位相機(DC)等，我們發現一些小尺寸液晶顯示器存在著閃動(Flicker)的問題，有些是很輕微的、有些則顯得比較嚴重，這是液晶顯示器的重要缺陷。 小尺寸液晶顯示器因面板上的寄生電容而產生穿通(Feed through)電壓的影響及液晶需要不斷的做正、負極性變換的關係，LCD會產生閃動的現象，傳統減輕閃動的方法為利用相同一組Common電壓的設定，來補償LCD正、負極性的差異，以減輕閃動的現象。但是以此方式生產，液晶顯示器會因為製程的差異，導致液晶顯示器有各自不同的Feed through電壓，所以出現了有些閃動很輕微、有些卻顯得比較嚴重的情況。於是有些液晶面板廠會在FPC上設計可變電阻的元件，供出廠時讓生產人員可調整Common電壓來減輕閃動，但這會增加液晶顯示器的元件成本、體積，及額外增加手動Common電壓的調校作業。 本文的目的在開發一套成本低廉、操作容易的LCD Flicker自動測試系統，先用CA-210色彩分析儀量測閃動(Flicker)大小，讓系統調整LCD Common電壓設定，找到每片LCD閃動到最輕微時的Common電壓設定，然後將此Common電壓設定值燒錄到LCD的OTP記憶體中，做為該液晶顯示器出廠後的開機初始值。透過本LCD Flicker測試系統，LCD模組廠可以快速且正確的管理整批生產之液晶顯示器，讓每片LCD的閃動現象降到最低。

The application of the small size liquid crystal display is very extensive, such as the cell-phone, MP3 Player and digital camera (DC),…We find some of small size liquid crystal display flicker existing, some are very slight, some seem more serious, this is an important defect of a liquid crystal display. The Feed-through of small size liquid crystal display is produced by parasitic capacity on the panel Influence. And the common voltage and liquid crystal need constant doing the positive and negative pole relation varying, LCD will produce the phenomenon flickered, and the tradition lightens the method of flickering as utilizing the same establishment of common voltage, to compensate the difference of LCD common positive and negative pole nature to come, in order to lighten the phenomenon flickered. But produce by this way, some liquid crystal display will make difference, cause liquid crystal display have difference of Feed through voltage, appear some flicker very slight, but some seem serious situation. Then some liquid crystal panel factories will design the component of the variable resistance on FPC, support when dispatching from the factory making producer adjustable Common voltage to lighten flicker to come, but this increase component cost and volume of liquid crystal display, and increase the operator loading at manual common voltage fine-tune. The purpose of this text is to develop a set of cheap cost, to operate and test the LCD Flicker easy through the system automatically, examines the flickers with the analysis instrument of CA-210 color analyzer, the LCD Common voltage is adjusted and sets up by the system, then find each LCD is it get most slight Common voltage when set up, and it will be recorded at OTP memory of driver IC, so initial value of the LCDs common voltage were dispatched from the factory. Pass this LCD flicker test systematically, liquid crystal display produced by the gross in management that LCD mould group's factory can be fast and correct, let the phenomenon of flickering of each one LCD lowest.