數(shù)字電視技術(shù)——顯示器件ppt課件

1、數(shù)字電視顯 示 技 術(shù).數(shù)字電視顯示技術(shù)的開展CRT顯示器液晶顯示器LCD等離子顯示器PDP投影顯示器等離子體PDP顯示技術(shù).A.B.C.D？.日光燈的發(fā)光特性對等離子體顯示器件具有重要意義.什么是等離子？它是怎樣發(fā)光的？等離子體是由自在流動(dòng)的離子帶電的原子和電子帶負(fù)電的粒子組成的氣體 在通常情況下，氣體主要由不帶電的粒子組成，假設(shè)在氣體中施加高電壓使氣體電離，這時(shí)的氣體就變成了等離子體。在穩(wěn)定等離子體中假設(shè)有電流穿行其中，那么帶負(fù)電的粒子就會(huì)沖向那些帶正電粒子的區(qū)域，而帶正電的粒子也會(huì)殺向那些帶負(fù)電粒子的區(qū)域 雙方的粒子不斷地進(jìn)展著撞擊。這些撞擊激發(fā)了等離子體中的氣體原子，促使它們發(fā)出了光。

2、這個(gè)任務(wù)原理很類似于普通日光燈 .等離子的發(fā)光原理.等離子體顯示器Plasma Display Panel等離子顯示器是一種利用氣體放電的顯示安裝，這種屏幕采用了等離子管作為發(fā)光元件。大量的等離子管陳列在一同構(gòu)成屏幕。每個(gè)等離子對應(yīng)的每個(gè)小室內(nèi)部充有氖氙氣體。在等離子管電極間加上高壓后，封在兩層玻璃之間的等離子管小室中的氣領(lǐng)會(huì)產(chǎn)生紫外光，從而鼓勵(lì)平板顯示器上的紅綠藍(lán)三基色熒光粉發(fā)出可見光。每個(gè)離子管作為一個(gè)像素，由這些像素的明暗和顏色變化組合，產(chǎn)生各種灰度和顏色的圖像，與顯像管發(fā)光類似 .PDP顯示器的分類PDP分為直流DC驅(qū)動(dòng)型和交流AC驅(qū)動(dòng)型兩種不同方式。直流型電極與放電氣體直接接觸，紫外

3、線的產(chǎn)生效率高，但顯示屏的構(gòu)造比較復(fù)雜，在目前商用彩色PDP中已很少用。交流型的電極外表涂敷一層介質(zhì)層，使其構(gòu)造類似于一個(gè)電容器。交流型PDP又分對向放電和外表放電兩種。目前的主流彩色PDP為三電極外表交流放電型 .外表放電型外表放電型ACPDP的掃描電極和維持電極Z統(tǒng)稱顯示電極位于放電介質(zhì)的同一側(cè)，使放電在前外表進(jìn)展，減少了帶電粒子對熒光粉的轟擊。外表放電型ACPDP的地址電極D位于放電介質(zhì)和惰性氣體的另一側(cè)，顯示電極的對面。在顯示驅(qū)動(dòng)時(shí)，首先在D和Y之間產(chǎn)生一個(gè)較高的電壓，擊穿惰性氣體產(chǎn)生放電，然后在Y和Z之間產(chǎn)生一個(gè)較低的電壓維持氣體放電。.PDP構(gòu)造表示圖.PDP構(gòu)造表示圖.等離子顯示

4、像素構(gòu)造表示圖Discharge ElectrodesFront GlassDielectric (MgO)Inert GasChamberColorSpecificSub-PixelPhosphorsRear GlassData Electrode.等離子顯示彩色像素單元構(gòu)造表示圖RGB.A discharge arc is generated when a potential is drivenacross the electrodes.How the Plasma Display Sub-pixel Works Cross Sectional View.The arc flashes t

5、he inert gas to plasma causing it to emit(invisible) ultraviolet radiation.How the Plasma Display Sub-pixel Works Cross Sectional View.The UV radiation in turn excites the color phosphors(green, in our example)How the Plasma Display Sub-pixel Works Cross Sectional View.which in turn emit a pulse of

6、light (again, green in thisexample, but red and blue work the same).How the Plasma Display Sub-pixel Works Cross Sectional View.which exits the display through the front glass paneland proceeds to the viewer.How the Plasma Display Sub-pixel Works Cross Sectional View.which exits the display through

7、the front glass paneland proceeds to the viewer.How the Plasma Display Sub-pixel Works Cross Sectional View.which exits the display through the front glass paneland proceeds to the viewer.How the Plasma Display Sub-pixel Works Cross Sectional View.which exits the display through the front glass pane

8、land proceeds to the viewer.How the Plasma Display Sub-pixel Works Cross Sectional View.which exits the display through the front glass paneland proceeds to the viewer.How the Plasma Display Sub-pixel Works Cross Sectional View.which exits the display through the front glass paneland proceeds to the

9、 viewer.How the Plasma Display Sub-pixel Works Cross Sectional View.which exits the display through the front glass paneland proceeds to the viewer.How the Plasma Display Sub-pixel Works Cross Sectional View.which exits the display through the front glass paneland proceeds to the viewer.How the Plas

10、ma Display Sub-pixel Works Cross Sectional View. 剛剛的動(dòng)畫除了演示出PDP等離子顯示的發(fā)光過程外，大家還可以發(fā)現(xiàn)一個(gè)什么問題？. 等離子放電發(fā)出的紫外線除了轟擊熒光物質(zhì)外，還有部分輻射到了顯示屏之外等離子顯示發(fā)光過程表示圖.How the Plasma RGB Pixel Works Cross Sectional ViewRGBEach sub-pixel is driven to its appropriate value.How the Plasma RGB Pixel Works Cross Sectional ViewRGBThe c

11、orresponding RGB light intensity for the pixel isemitted from the display.How the Plasma RGB Pixel Works Cross Sectional ViewRGBEyeThese colors blend on the way to the users eye and areperceived as a combined color.等離子顯示如何控制發(fā)光強(qiáng)度？LowIntensityHighIntensityR？.Intensity is Controlled by Pulsing the Outp

12、ut Cross Sectional ViewLowIntensityHighIntensity.Intensity is Controlled by Pulsing the Output Cross Sectional ViewLowIntensityHighIntensity.Intensity is Controlled by Pulsing the Output Cross Sectional ViewLowIntensityHighIntensity.Intensity is Controlled by Pulsing the Output Cross Sectional ViewL

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16、ross Sectional ViewLowIntensityHighIntensity.Intensity is Controlled by Pulsing the Output Cross Sectional ViewLowIntensityHighIntensity.Intensity is Controlled by Pulsing the Output Cross Sectional ViewLowIntensityHighIntensity.Intensity is Controlled by Pulsing the Output Cross Sectional ViewLowIn

17、tensityHighIntensity.Intensity is Controlled by Pulsing the Output Cross Sectional ViewLowIntensityHighIntensity.Intensity is Controlled by Pulsing the Output Cross Sectional ViewLowIntensityHighIntensity.Intensity is Controlled by Pulsing the Output Cross Sectional ViewLowIntensityHighIntensity.Int

18、ensity is Controlled by Pulsing the Output Cross Sectional ViewLowIntensityHighIntensity.Intensity is Controlled by Pulsing the Output Cross Sectional ViewLowIntensityHighIntensity.Intensity is Controlled by Pulsing the Output Cross Sectional ViewLowIntensityHighIntensity.Intensity is Controlled by

19、Pulsing the Output Cross Sectional ViewLowIntensityHighIntensity？.PDP顯示屏灰度等級的控制輝光放電的電流對應(yīng)于發(fā)光強(qiáng)度不容易控制， PDP利用的是其亮與不亮的兩態(tài)特性，以改動(dòng)發(fā)光時(shí)間的長短來實(shí)現(xiàn)灰度等級的控制，所以PDP是一種數(shù)字顯示器件。 PDP發(fā)光時(shí)間的控制即灰度由子場驅(qū)動(dòng)技術(shù)實(shí)現(xiàn)，每場周期被分為八個(gè)子場或更多。在常用的尋址顯示分別驅(qū)動(dòng)法中，每個(gè)子場又分為啟動(dòng)期、尋址期和維持期。啟動(dòng)期和尋址期在各子場中時(shí)間長短一樣，期間全屏不發(fā)光，只是激活應(yīng)發(fā)光的象元。維持期的長短那么各不一樣，正比于其中包含的脈沖數(shù)采用二進(jìn)制編碼時(shí)各子場

20、內(nèi)放電脈沖的比值，期間被激活的象元同時(shí)點(diǎn)亮。某象元的灰度等級由一幀期間加在其上的總的放電脈沖數(shù)決議，當(dāng)采用子場驅(qū)動(dòng)時(shí)，二進(jìn)制編碼一共可以獲得個(gè)灰度等級 .尋址與顯示分別的子場驅(qū)動(dòng)技術(shù).ACPDP驅(qū)動(dòng)方式的優(yōu)勢ACPDP的特性使得顯示電極與地址電極交叉點(diǎn)構(gòu)成的小放電管不僅是一個(gè)可控發(fā)光元件，而且是一個(gè)可控存儲(chǔ)單元，整屏既是發(fā)光單元的二維陣列，又是一個(gè)矩陣存儲(chǔ)器，每個(gè)發(fā)光元件也只需發(fā)光和不發(fā)光兩個(gè)形狀。ACPDP實(shí)踐上是一個(gè)數(shù)字器件，可以大量采用數(shù)字圖象處置技術(shù)，且數(shù)字圖象信號(hào)無須經(jīng)過D/A變換，可直接用于驅(qū)動(dòng)顯示屏 .ACPDP驅(qū)動(dòng)方式的優(yōu)勢表示圖.PDP顯示器的技術(shù)優(yōu)勢與CRT顯示器相比PDP

21、顯示器的體積更小、分量更輕，而且無X射線輻射。由于PDP各個(gè)發(fā)光單元的構(gòu)造完全一樣，因此不會(huì)出現(xiàn)顯像管常見的圖像的幾何變形。PDP屏幕亮度非常均勻沒有亮區(qū)的和暗區(qū)；而傳統(tǒng)顯像管的亮度-屏幕中心總是比周圍亮度要高一些。PDP不會(huì)受磁場的影響，具有更好的環(huán)境順應(yīng)才干。PDP屏幕不存在聚焦的問題。因此，顯像管某些區(qū)域因聚焦不良或年月已久開場散焦的問題得以處理，不會(huì)產(chǎn)生顯像管的顏色漂移景象。外表平直使大屏幕邊角處的失真和色純度變化得到徹底改善。高亮度、大視角、全彩色和高對比度，使PDP圖像更加明晰，顏色更加艷麗，效果更加理想，令傳統(tǒng)電視嘆為觀止.PDP顯示器的技術(shù)優(yōu)勢與LCD液晶顯示器相比PDP顯示亮

22、度高，屏幕亮度高達(dá)150LUX，因此可以在亮堂的環(huán)境之下欣賞大幅畫面的視訊節(jié)目。顏色復(fù)原性好，灰度豐富，能提供格外亮麗、均勻平滑的畫面。PDP視野開闊，PDP的視角高達(dá)160度，普通電視機(jī)的大于160度的地方觀看畫面已嚴(yán)重失真，而液晶顯示器視角只需40度左右，更是無法與PDP的效果比較。對迅速變化的畫面呼應(yīng)速度快。此外，PDP平而薄的外型也使其優(yōu)勢更加明顯.等離子顯示技術(shù)的開展1954年，美國，DC驅(qū)動(dòng)PDP的發(fā)表1956年，美國，冷陰極放電顯示管的開發(fā)1966年，美國，存儲(chǔ)型AC驅(qū)動(dòng)PDP的發(fā)表1968年，荷蘭，用DC驅(qū)動(dòng)的PDP顯示電視圖像1969年，美國，自掃描型DC驅(qū)動(dòng)PDP的開發(fā)1978年，日本，16英寸DC驅(qū)動(dòng)彩色PDP電視機(jī)的試制1985年，日本，脈沖存儲(chǔ)型DC驅(qū)動(dòng)彩色PDP電視機(jī)的開發(fā)1993年，日本，21英