LED中英文翻譯論文

PAGEword文檔可自由復(fù)制編輯FirstLEDSummary一LED概述LED(LightEmittingDiode),light-emittingdiode,isasolidstatesemiconductordevices,whichcanbedirectlyconvertedintoelectricitytolight.LEDistheheartofasemiconductorchip,thechipisattachedtooneendofastent,isthenegativeside,theotherendofthepowerofthecathode,theentirechippackagetobeepoxyresin.Semiconductorchipiscomposedoftwoparts,partoftheP-typesemiconductor,itinsidethehole-dominated,theothersideistheN-typesemiconductor,hereismainlyelectronic.Butlinkingthetwosemiconductors,amongthemtheformationofa"PNjunction."Whenthecurrentthroughthewiresroleinthischip,willbepushinge-P,Pzoneintheholewithelectroniccomposite,andthentobeissuedintheformofphotonenergy,andthisistheprincipleofLEDluminescence.Thewavelengthoflightthatisthecoloroflight,isformedbythePNjunctionofthedecisionsofthematerial.LED（LightEmittingDiode），發(fā)光二極管，是一種固態(tài)的半導(dǎo)體器件，它可以直接把電轉(zhuǎn)化為光。LED的心臟是一個(gè)半導(dǎo)體的晶片，晶片的一端附在一個(gè)支架上，一端是負(fù)極，另一端連接電源的正極，使整個(gè)晶片被環(huán)氧樹脂封裝起來。半導(dǎo)體晶片由兩部分組成，一部分是P型半導(dǎo)體，在它里面空穴占主導(dǎo)地位，另一端是N型半導(dǎo)體，在這邊主要是電子。但這兩種半導(dǎo)體連接起來的時(shí)候，它們之間就形成一個(gè)“P-N結(jié)”。當(dāng)電流通過導(dǎo)線作用于這個(gè)晶片的時(shí)候，電子就會(huì)被推向P區(qū)，在P區(qū)里電子跟空穴復(fù)合，然后就會(huì)以光子的形式發(fā)出能量，這就是LED發(fā)光的原理。而光的波長(zhǎng)也就是光的顏色，是由形成P-N結(jié)的材料決定的。SecondLEDhistoryanddevelopment50yearsago,peoplehavetounderstandsemiconductormaterialscanproducelightofthebasicknowledge,thefirstcommercialdiodesin1960.EnglishistheLEDlightemittingdiode(LED)acronym,anditsbasicstructureisanelectroluminescentsemiconductormaterials,placedinawirerack,thensealedwithepoxyresinaround,thatis,solidpackage,Therefore,theprotectionoftheinternalbatteriescanplaytheroleofline,sotheseismicperformanceLEDgood.LEDisthecoreoftheP-typesemiconductorandcomponentsoftheN-typesemiconductorchips,theP-typesemiconductorandN-typesemiconductorbetweenatransitionlayer,calledthePNjunction.InsomesemiconductormaterialsinthePNjunction,theinjectionofasmallnumberofcarrier-carrierandthemajorityoftheextratimewillbeintheformoflightenergytorelease,thusthepowertodirectconversionofsolarenergy.PNjunctiononreversevoltage,afewhard-carrierinjection,itisnotluminous.Thisuseofinjectionelectroluminescentdiodesisproducedbytheprincipleoflight-emittingdiodes,commonlyknownasLED.Whenitinapositivestateofthework(thatis,atbothendswithforwardvoltage),thecurrentflowsfromtheLEDanode,cathode,semiconductorcrystalsontheissuefromtheultraviolettoinfraredlightofdifferentcolors,lightandthestrengthofthecurrents.InstrumentsusedforthefirstLEDlightsourceinstructions,butallkindsoflightcoloredLEDlightsintrafficandlargescreenhasbeenwidelyapplied,haveaverygoodeconomicandsocialbenefits.The12-inchredtrafficlightsasanexample,isusedintheUnitedStateshavelonglife,low-efficiency140wattincandescentlampasalightsource,itproduced2,000lumensofwhitelight.Theredfilter,theloss-90percent,only200lumensofredlight.Inthelightofthenewdesign,Lumiledscompanieshave18redLEDlightsource,includingthelossofcircuit,atotalpowerconsumptionof14wattstogeneratethesameopticaleffect.AutomotiveLEDlightsisalsothesourceofimportantareas.Forgenerallighting,peopleneedmorewhitelightsources.The1998whiteLEDsuccessfuldevelopment.ThisistheGaNLEDchipandYttriumAluminumGarnet(YAG)packagetogethercause.GaNchipoftheBlu-ray(λp=465nm,Wd=30nm),madeofhigh-temperaturesinteringoftheCe3+YAGphosphorsexcitedbythisBlu-rayafterirradiatingayellow,thepeak550nm.Blue-chipinstalledintheLED-basedWanxingreflectioninthecavity,coveredwitharesinmixedwithYAGthinlayer,about200-500nm.LED-basedtabletsissuedbytheBlu-rayabsorptionpartofthephosphor,thephosphoranotherpartoftheBlu-rayandayellowlightmixed,canbeawhite.Now,theInGaN/YAGwhiteLED,YAGphosphorbychangingthechemicalcompositionofthephosphorlayerandadjustthethicknessofthe3500-10000Kcolortemperaturecanbecoloredwhite.ThisblueLEDthroughthemethodbywhite,constructedsimple,low-cost,hightechnologyismature,sousethemost.ThedevelopmentofLEDdisplaycanbedividedintothefollowingphases:firstphase1990to1995,mainlymonochromeand16colorgraphicsscreen.Usedtodisplaytextandsimpleimages,mainlyusedinrailwaystations,financialsecurities,banks,postofficesandotherpublicplaces,aspublicinformationdisplaytools.Thesecondstageisfrom1995to1999,therehavebeen64,256levelgray-scaletwo-colorvideoscreen.Videocontroltechnology,imageprocessing,opticalfibercommunicationtechnologyapplicationswillenhancetheLEDdisplaytoanewlevel.LEDdisplaycontrolLSIchipsspecialatthistimedevelopedbydomesticcompanies,andcanbeapplied.Thethirdstage,from1999,red,puregreen,blueLEDinbulkintoChina,whiledomesticenterprisesin-depthresearchanddevelopmentwork,usingred,green,andblueLEDproductionoffull-colordisplayhasbeenwidelyused,pouredintosportsstadiums,conventioncenters,squaresandotherpublicplaces,whichwillbringthedomesticlarge-screenfull-colorera.WiththerapiddevelopmentofLEDmaterialsmarket,surfacemountdeviceisavailablefrom2001,mainlyusedinindoorfullcolor,anditshighbrightness,colorful,lowtemperaturecharacteristics,thepointspacingcanbeadjustedbydifferentpriceRequirementswereaccepted,injusttwoyearstime,productsaleshavemorethan300millionyuan,surfacemountfull-colorLEDdisplayapplicationmarketenteredthenewcentury.Tomeetthe2008OlympicGames,"downsizing"plan,Liarddevelopedasurfacemountdualcolordisplays,alotoftimeforthetrainingcenterandgamescoring.FullcolorinOlympicvenues,inordertotighteninvestment,fullcolorwayismostlydetachable,liveduringtheOlympicGamesasatoolcanbeusedforrentalaftertheevent,astheperformanceofnationalpoliciessuchaspublicplaces,toolsreleasedbyInthiswaycostrecoveryassoonaspossible.Onthemarket,China'saccessiontoWTO,Beijing'ssuccessfulOlympicbidandsoon,intothedevelopmentofLEDdisplayindustry,anewopportunity.DomesticLEDdisplaymarketcontinuestogrow,currentlyinthedomesticmarket,domesticLEDdisplaymarketshareofnearly95%.LEDdisplaytheinternationalmarketcapacityisexpectedto30%ayeargrowthrate.Currently,LEDdisplaymanufacturersconcentratedprimarilyinJapan,NorthAmerica,ChinaLEDmanufacturersinwhichtheinsignificantshareofexports.Accordingtoincompletestatistics,theworld,thereareatleast150manufacturersfullcolor,inwhichproductsarecomplete,thelargercompanyhassome30orso.二LED歷史及發(fā)展現(xiàn)狀50年前人們已經(jīng)了解半導(dǎo)體材料可產(chǎn)生光線的基本知識(shí)，第一個(gè)商用二極管產(chǎn)生于1960年。LED是英文lightemittingdiode（發(fā)光二極管）的縮寫，它的基本結(jié)構(gòu)是一塊電致發(fā)光的半導(dǎo)體材料，置于一個(gè)有引線的架子上，然后四周用環(huán)氧樹脂密封，即固體封裝，所以能起到保護(hù)內(nèi)部芯線的作用，所以LED的抗震性能好。發(fā)光二極管的核心部分是由P型半導(dǎo)體和N型半導(dǎo)體組成的晶片，在P型半導(dǎo)體和N型半導(dǎo)體之間有一個(gè)過渡層，稱為P-N結(jié)。在某些半導(dǎo)體材料的PN結(jié)中，注入的少數(shù)載流子與多數(shù)載流子復(fù)合時(shí)會(huì)把多余的能量以光的形式釋放出來，從而把電能直接轉(zhuǎn)換為光能。PN結(jié)施加反向電壓時(shí)，少數(shù)載流子難以注入，故不發(fā)光。這種利用注入式電致發(fā)光原理制作的二極管叫發(fā)光二極管，通稱LED。當(dāng)它處于正向工作狀態(tài)時(shí)（即兩端加上正向電壓），電流從LED陽極流向陰極時(shí)，半導(dǎo)體晶體就發(fā)出從紫外到紅外不同顏色的光線，光的強(qiáng)弱與電流有關(guān)。最初LED用作儀器儀表的指示光源，后來各種光色的LED在交通信號(hào)燈和大面積顯示屏中得到了廣泛應(yīng)用，產(chǎn)生了很好的經(jīng)濟(jì)效益和社會(huì)效益。以12英寸的紅色交通信號(hào)燈為例，在美國(guó)本來是采用長(zhǎng)壽命、低光效的140瓦白熾燈作為光源，它產(chǎn)生2000流明的白光。經(jīng)紅色濾光片后，光損失90%，只剩下200流明的紅光。而在新設(shè)計(jì)的燈中，Lumileds公司采用了18個(gè)紅色LED光源，包括電路損失在內(nèi)，共耗電14瓦，即可產(chǎn)生同樣的光效。汽車信號(hào)燈也是LED光源應(yīng)用的重要領(lǐng)域。對(duì)于一般照明而言，人們更需要白色的光源。1998年白光的LED開發(fā)成功。這種LED是將GaN芯片和釔鋁石榴石（YAG）封裝在一起做成。GaN芯片發(fā)藍(lán)光（λp=465nm，Wd=30nm），高溫?zé)Y(jié)制成的含Ce3+的YAG熒光粉受此藍(lán)光激發(fā)后發(fā)出黃色光射，峰值550nm。藍(lán)光LED基片安裝在碗形反射腔中，覆蓋以混有YAG的樹脂薄層，約200-500nm。LED基片發(fā)出的藍(lán)光部分被熒光粉吸收，另一部分藍(lán)光與熒光粉發(fā)出的黃光混合，可以得到得白光。現(xiàn)在，對(duì)于InGaN/YAG白色LED，通過改變YAG熒光粉的化學(xué)組成和調(diào)節(jié)熒光粉層的厚度，可以獲得色溫3500-10000K的各色白光。這種通過藍(lán)光LED得到白光的方法，構(gòu)造簡(jiǎn)單、成本低廉、技術(shù)成熟度高，因此運(yùn)用最多。LED顯示屏的發(fā)展可分為以下幾個(gè)階段：第一階段為1990年到1995年，主要是單色和16級(jí)雙色圖文屏。用于顯示文字和簡(jiǎn)單圖片，主要用在車站、金融證券、銀行、郵局等公共場(chǎng)所，作為公共信息顯示工具。第二階段是1995年到1999年，出現(xiàn)了64級(jí)、256級(jí)灰度的雙基色視頻屏。視頻控制技術(shù)、圖像處理技術(shù)、光纖通信技術(shù)等的應(yīng)用將LED顯示屏提升到了一個(gè)新的臺(tái)階。LED顯示屏控制專用大規(guī)模集成電路芯片也在此時(shí)由國(guó)內(nèi)企業(yè)開發(fā)出來并得以應(yīng)用。第三階段從1999年開始，紅、純綠、純藍(lán)LED管大量涌入中國(guó)，同時(shí)國(guó)內(nèi)企業(yè)進(jìn)行了深入的研發(fā)工作，使用紅、綠、藍(lán)三原色LED生產(chǎn)的全彩色顯示屏被廣泛應(yīng)用，大量進(jìn)入體育場(chǎng)館、會(huì)展中心、廣場(chǎng)等公共場(chǎng)所，從而將國(guó)內(nèi)的大屏幕帶入全彩時(shí)代。隨著LED原材料市場(chǎng)的迅猛發(fā)展，表面貼裝器件從2001年面世，主要用在室內(nèi)全彩屏，并且以其亮度高、色彩鮮艷、溫度低的特性，可隨意調(diào)整的點(diǎn)間距，被不同價(jià)位需求者所接受，在短短兩年多時(shí)間內(nèi)，產(chǎn)品銷售額已超過3億元，表面貼裝全彩色LED顯示屏應(yīng)用市場(chǎng)進(jìn)入新世紀(jì)。為了適應(yīng)2008年奧運(yùn)會(huì)的“瘦身”計(jì)劃，利亞德開發(fā)了表面貼裝雙基色顯示屏，大量用于訓(xùn)練館和比賽計(jì)時(shí)計(jì)分系統(tǒng)。在奧運(yùn)場(chǎng)館全彩屏方面，為緊縮投資，全彩屏大部分采用可拆卸方式，奧運(yùn)期間可作為實(shí)況轉(zhuǎn)播工具，賽事結(jié)束后可用于租賃，作為演出、國(guó)家政策發(fā)布等公共場(chǎng)合應(yīng)用工具，通過這種方式可盡快收回成本。就市場(chǎng)而言，中國(guó)加入WTO、北京申奧成功等，成為L(zhǎng)ED顯示屏產(chǎn)業(yè)發(fā)展的新契機(jī)。國(guó)內(nèi)LED顯示屏市場(chǎng)保持持續(xù)增長(zhǎng)，目前在國(guó)內(nèi)市場(chǎng)上，國(guó)產(chǎn)LED顯示屏的市場(chǎng)占有率近95%。國(guó)際上LED顯示屏的市場(chǎng)容量預(yù)計(jì)以每年30%的速度在增長(zhǎng)。目前，LED顯示屏的主要制造廠商集中在日本、北美等地，我國(guó)LED制造廠商出口的份額在其中微不足道。據(jù)不完全統(tǒng)計(jì)，世界上目前至少有150家廠商生產(chǎn)全彩屏，其中產(chǎn)品齊全，規(guī)模較大的公司約有30家左右。ThirdLEDadvantagesConductorlight-emittingdiode(LED)asathird-generationsemiconductorlightingsource.Thisfantasticproducthasalotofadvantages:(1)efficientlight:spectraofalmostallconcentratedinthevisiblelightfrequency,theefficiencycanreach80%-90%.Theluminousefficiencyofincandescentvisiblelightefficiencyofalmost10%-20%only.(2)highqualityoflight:notasaresultofspectrumUVandinfrared,thereisnoheat,noradiation,istypicallyagreenlightillumination.(3)energyconsumptionofthesmall:singlepowergenerally0.05-1w,throughtheclustercanbetailoredtomeetdifferentneeds,andwasteverylittle.Asalightsource,underthebrightnessinthesamepowerconsumptionofonlyordinaryincandescent1/8-10.(4)longlife:fluxattenuationto70%ofthestandardlifeexpectancyis100,000hours.Asemiconductorlightcanbeusedundernormalcircumstances50years,evenifthelonglifeofthepeople,lifewillbeuseduptotwolights.(5)durableandreliable:Notungstenwire,glassandothereasilydamagedcomponents,non-normalretirementrateisverysmall,verylowmaintenancecosts.(6)theapplicationofflexibility:smallsize,canflatpack,easytodevelopintoashortthinproducts,makepoint,line,facevariousformsofspecificapplications.(7)Security:workingvoltage1.5-5vorlessinbetweenthecurrent20-70mAinbetween.(8)green:recyclablewaste,nopollution,unlikefluorescentlampscontainingmercuryasingredients.(9)responsetimeisshort:toadapttofrequentandhigh-frequencyswitchingoperationofoccasions.三LED優(yōu)點(diǎn)導(dǎo)體發(fā)光二極管(LED)作為第三代半導(dǎo)體照明光源。這種產(chǎn)品具有很多夢(mèng)幻般優(yōu)點(diǎn)：(1)光效率高：光譜幾乎全部集中于可見光頻率，效率可以達(dá)到80%-90%。而光效差不多的白熾燈可見光效率僅為10%-20%。(2)光線質(zhì)量高：由于光譜中沒有紫外線和紅外線，故沒有熱量，沒有輻射，屬于典型的綠色照明光源。(3)能耗?。?jiǎn)误w功率一般在0.05-1w，通過集群方式可以量體裁衣地滿足不同的需要，浪費(fèi)很少。以其作為光源，在同樣亮度下耗電量?jī)H為普通白熾燈的1/8-10。(4)壽命長(zhǎng)：光通量衰減到70%的標(biāo)準(zhǔn)壽命是10萬小時(shí)。一個(gè)半導(dǎo)體燈正常情況下可以使用50年，即使長(zhǎng)命百歲的人，一生最多也就用2只燈。(5)可靠耐用：沒有鎢絲、玻殼等容易損壞的部件，非正常報(bào)廢率很小，維護(hù)費(fèi)用極為低廉。(6)應(yīng)用靈活：體積小，可以平面封裝，易開發(fā)成輕薄短小的產(chǎn)品，做成點(diǎn)、線、面各種形式的具體應(yīng)用產(chǎn)品。(7)安全：?jiǎn)挝还ぷ麟妷捍笾略?.5-5v之間，工作電流在20-70mA之間。(8)綠色環(huán)保：廢棄物可回收，沒有污染，不像熒光燈一樣含有汞成分。(9)響應(yīng)時(shí)間短：適應(yīng)頻繁開關(guān)以及高頻運(yùn)作的場(chǎng)合FourthClassificationofLEDdisplay1,colorbycolorcanbedividedinto

Single-colordisplay:Singlecolor(redorgreen).

Two-colordisplay:redandgreendual-color,256grayscalelevels,candisplay65,536colors.

Full-colorscreen:red,green,bluecolor,256grayscalefullcolordisplaycandisplaymorethan16millionkindsofcolors.

2,accordingtodisplaydeviceclassification

LEDDigitalDisplay:7segmentdisplaydevicesforthedigitalcontrolcode,suitableforproductionoftheclockscreen,theinterestratescreens,showingthenumberofelectronicdisplay.

LEDdot-matrixgraphicdisplay:displaydeviceisarrangedbyanumberofuniformcompositionofthedot-matrixLEDdisplaymodules,suitableforbroadcasttext,imageinformation.

LEDvideodisplay:displaydevicesareformedbyanumberoflight-emittingdiodesthatcandisplayvideo,animationandothervideofiles.

3,byusingtheoccasioncategories

IndoorDisplay:LEDspotssmaller,generalΦ3mm-Φ8mm,showsthegeneralareaofafewtomorethantensquaremeters.

OutdoorDisplay:dozensofsquaremetersinsizetoseveralhundredsquaremeters,highbrightness,canworkinthesun,withwind,rain,waterresistant.

4,classifiedaccordingtolightspotdiameter

Indoorscreen:Φ3mm,Φ3.75mm,Φ5mm,

Roomexternalscreen:Φ10mm,Φ12mm,Φ16mm,Φ19mm,Φ20mm,Φ21mm,Φ22mm,Φ26mm

Roomexternalscreenasthebasicunitoflightemittingtube,LEDtubeprincipleisasetofred,green,andbluelight-emittingdiodesealedinaplasticbarrelandjointlydevelop

5,Displayastatic,horizontalscroll,verticalscrollandflipdisplay.Oneblockmodulecontroldrive12(uptocontrol24)8X8DotMatrix,atotalof16X48dotmatrix(or32X48dotmatrix),isasingleblockofMAX7219(orPS7219,HD7279,ZLG7289and8279,andthelikeLEDdisplaydrivermodule)12times(or24times)!Canuse"cascade"approachthecompositionofanylargedotmatrixdisplay.Effects,goodpowerconsumption,andtheMAX7219circuitthantheuseoflowercost.

四LED顯示屏的分類

1、按顏色基色可以分為

單基色顯示屏:單一顏色（紅色或綠色）。

雙基色顯示屏：紅和綠雙基色，256級(jí)灰度、可以顯示65536種顏色。

全彩色顯示屏：紅、綠、藍(lán)三基色，256級(jí)灰度的全彩色顯示屏可以顯示一千六百多萬種顏色。

2、按顯示器件分類

LED數(shù)碼顯示屏：顯示器件為7段碼數(shù)碼管，適于制作時(shí)鐘屏、利率屏等，顯示數(shù)字的電子顯示屏。

LED點(diǎn)陣圖文顯示屏：顯示器件是由許多均勻排列的發(fā)光二極管組成的點(diǎn)陣顯示模塊，適于播放文字、圖像信息。

LED視頻顯示屏：顯示器件是由許多發(fā)光二極管組成，可以顯示視頻、動(dòng)畫等各種視頻文件。

3、按使用場(chǎng)合分類

室內(nèi)顯示屏：發(fā)光點(diǎn)較小，一般Φ3mm--Φ8mm，顯示面積一般幾至十幾平方米。

室外顯示屏：面積一般幾十平方米至幾百平方米，亮度高，可在陽光下工作，具有防風(fēng)、防雨、防水功能。

4、按發(fā)光點(diǎn)直徑分類

室內(nèi)屏：Φ3mm、Φ3.75mm、Φ5mm、

室外屏：Φ10mm、Φ12mm、Φ16mm、Φ19mm、Φ20mm、Φ21mm、Φ22mm、Φ26mm

室外屏發(fā)光的基本單元為發(fā)光筒，發(fā)光筒的原理是將一組紅、綠、藍(lán)發(fā)光二極管封在一個(gè)塑料筒內(nèi)共同發(fā)

5、顯示方式有靜態(tài)、橫向滾動(dòng)、垂直滾動(dòng)和翻頁顯示等。單塊模塊控制驅(qū)動(dòng)12塊（最多可控制24塊）8X8點(diǎn)陣，共16X48點(diǎn)陣（或32X48點(diǎn)陣），是單塊MAX7219（或PS7219、HD7279、ZLG7289及8279等類似LED顯示驅(qū)動(dòng)模塊）的12倍（或24倍）！可采用“級(jí)聯(lián)”的方式組成任意點(diǎn)陣大顯示屏。顯示效果好，功耗小，且比采用MAX7219電路的成本更低。FifthLEDapplicationsItisasemiconductorlight-emittingdiodebycontrollingthedisplay,whichprobablylooklikethatfromlotsofsmallredlightsareusuallyformedbythebrightlightsofftoshowcharacter.Usedtodisplaytext,graphics,images,animations,quotes,video,videosignalsandotherinformationonthedisplayscreen.GraphicdisplayandLEDdisplayintothevideodisplaybytheLEDmatrixblocks.GraphicdisplayscanbesynchronizedwiththecomputerdisplayChinesecharacters,Englishtextandgraphics;videodisplayusingmicro-computercontrol,graphics,images,andMao,real-time,synchronization,clearmessagetothebroadcastofavarietyofinformationdissemination,butalsoshowstwodimensional,three-dimensionalanimation,video,TV,VCDprogramsandliveon.LEDdisplayshowsthescreenbrightlycolored,three-dimensionalsenseofstrong,static,suchaspainting,movingasthefilmiswidelyusedinfinance,tax,business,telecommunications,sports,advertising,industrialenterprises,transport,educationsystems,stations,docks,airports,shoppingmalls,hospitals,hotels,banks,securitiesmarkets,constructionmarket,auctionhouses,industrialenterprisesinmanagementandotherpublicplaces.LEDdisplaycanshowchangesinthenumbers,text,graphicsandvideo;notonlycanbeusedintheindoorenvironmentcanalsobeusedforoutdoorenvironment,withaprojector,TVwall,LCDscreencannotmatchadvantage.五LED應(yīng)用范圍LED是一種通過控制半導(dǎo)體發(fā)光二極管的顯示方式，其大概的樣子就是由很多個(gè)通常是紅色的小燈組成，靠燈的亮滅來顯示字符。用來顯示文字、圖形、圖像、動(dòng)畫、行情、視頻、錄像信號(hào)等各種信息的顯示屏幕。LED顯示屏分為圖文顯示屏和視頻顯示屏，均由LED矩陣塊組成。圖文顯示屏可與計(jì)算機(jī)同步顯示漢字、英文文本和圖形；視頻顯示屏采用微型計(jì)算機(jī)進(jìn)行控制，圖文、圖像并茂，以實(shí)時(shí)、同步、清晰的信息傳播方式播放各種信息，還可顯示二維、三維動(dòng)畫、錄像、電視、VCD節(jié)目以及現(xiàn)場(chǎng)實(shí)況。LED顯示屏顯示畫面色彩鮮艷，立體感強(qiáng)，靜如油畫，動(dòng)如電影，廣泛應(yīng)用于金融、稅務(wù)、工商、郵電、體育、廣告、廠礦企業(yè)、交通運(yùn)輸、教育系統(tǒng)、車站、碼頭、機(jī)場(chǎng)、商場(chǎng)、醫(yī)院、賓館、銀行、證券市場(chǎng)、建筑市場(chǎng)、拍賣行、工業(yè)企業(yè)管理和其它公共場(chǎng)所。LED顯示屏可以顯示變化的數(shù)字、文字、圖形圖像；不僅可以用于室內(nèi)環(huán)境還可以用于室外環(huán)境，具有投影儀、電視墻、液晶顯示屏無法比擬的優(yōu)點(diǎn)。SixthLEDscreentestmethodAlookatScreensize,appearance,smoothness,withthescreenconnectionandsoon

Secondlookafterthedeadpixelscreenlightup,notinnotwithinthescopeof(ingeneralthescreenisbasicallygonenow)

Colorconsistency,displaytextisnormal,displaypictures,playfullscreenfullcolortowhite,red,green,andblue.六LED顯示屏檢驗(yàn)方法一看屏體規(guī)格，外觀，平整度，屏內(nèi)的連線等二看屏點(diǎn)亮后壞點(diǎn)，在不在不范圍之內(nèi)，（一般來說現(xiàn)在的屏基本上沒有了）

色差一致性，顯示文字是否正常，顯示屏圖片等，全彩的要全屏打白色，紅，綠，藍(lán)。

HowLightEmittingDiodesWorkLightemittingdiodes,commonlycalledLEDs,arerealunsungheroesintheelectronicsworld.Theydodozensofdifferentjobsandarefoundinallkindsofdevices.Amongotherthings,theyformthenumbersondigitalclocks,transmitinformationfromremotecontrols,lightupwatchesandtellyouwhenyourappliancesareturnedon.Collectedtogether,theycanformimagesonajumbotelevisionscreenorilluminateatrafficlight.Basically,LEDsarejusttinylightbulbsthatfiteasilyintoanelectricalcircuit.Butunlikeordinaryincandescentbulbs,theydon'thaveafilamentthatwillburnout,andtheydon'tgetespeciallyhot.Theyareilluminatedsolelybythemovementofelectronsinasemiconductormaterial,andtheylastjustaslongasastandardtransistor.Inthisarticle,we'llexaminethesimpleprinciplesbehindtheseubiquitousblinkers,illuminatingsomecoolprinciplesofelectricityandlightintheprocess.WhatisaDiode?Adiodeisthesimplestsortofsemiconductordevice.Broadlyspeaking,asemiconductorisamaterialwithavaryingabilitytoconductelectricalcurrent.Mostsemiconductorsaremadeofapoorconductorthathashadimpurities(atomsofanothermaterial)addedtoit.Theprocessofaddingimpuritiesiscalleddoping.InthecaseofLEDs,theconductormaterialistypicallyaluminum-gallium-arsenide.Inpurealuminum-gallium-arsenide,alloftheatomsbondperfectlytotheirneighbors,leavingnofreeelectrons(negatively-chargedparticles)toconductelectriccurrent.Indopedmaterial,additionalatomschangethebalance,eitheraddingfreeelectronsorcreatingholeswhereelectronscango.Eitheroftheseadditionsmakethematerialmoreconductive.AsemiconductorwithextraelectronsiscalledN-typematerial,sinceithasextranegatively-chargedparticles.InN-typematerial,freeelectronsmovefromanegatively-chargedareatoapositivelychargedarea.AsemiconductorwithextraholesiscalledP-typematerial,sinceiteffectivelyhasextrapositively-chargedparticles.Electronscanjumpfromholetohole,movingfromanegatively-chargedareatoapositively-chargedarea.Asaresult,theholesthemselvesappeartomovefromapositively-chargedareatoanegatively-chargedarea.AdiodecomprisesasectionofN-typematerialbondedtoasectionofP-typematerial,withelectrodesoneachend.Thisarrangementconductselectricityinonlyonedirection.Whennovoltageisappliedtothediode,electronsfromtheN-typematerialfillholesfromtheP-typematerialalongthejunctionbetweenthelayers,formingadepletionzone.Inadepletionzone,thesemiconductormaterialisreturnedtoitsoriginalinsulatingstate--alloftheholesarefilled,sotherearenofreeelectronsoremptyspacesforelectrons,andchargecan'tflow.Togetridofthedepletionzone,youhavetogetelectronsmovingfromtheN-typeareatotheP-typeareaandholesmovinginthereversedirection.Todothis,youconnecttheN-typesideofthediodetothenegativeendofacircuitandtheP-typesidetothepositiveend.ThefreeelectronsintheN-typematerialarerepelledbythenegativeelectrodeanddrawntothepositiveelectrode.TheholesintheP-typematerialmovetheotherway.Whenthevoltagedifferencebetweentheelectrodesishighenough,theelectronsinthedepletionzoneareboostedoutoftheirholesandbeginmovingfreelyagain.Asaresult,thedepletionzonedisappears.WhenthenegativeendofthecircuitishookeduptotheN-typelayerandthepositiveendishookeduptoP-typelayer,electronsandholesstartmoving.IftheP-typesideisconnectedtothenegativeendofthecircuitandtheN-typesideisconnectedtothepositiveend,currentwillnotflow.Nocurrentflowsacrossthejunctionbecausetheholesandtheelectronsareeachmovinginthewrongdirection.WhenthepositiveendofthecircuitishookeduptotheN-typelayerandthenegativeendishookeduptotheP-typelayer,thedepletionzonegetsbigger.Theinteractionbetweenelectronsandholeshasaninterestingeffect--itgenerateslight!Inthenextsection,we'llfindoutexactlywhythisis.HowCanaDiodeProduceLight?Lightisaformofenergythatcanbereleasedbyanatom.Itismadeupofmanysmallparticle-likepacketsthathaveenergy.Theseparticles,calledphotons,arethemostbasicunitsoflight.Photonsarereleasedasaresultofmovingelectrons.Inanatom,electronsmoveinorbitalsaroundthenucleus.Electronsindifferentorbitalshavedifferentamountsofenergy.Generallyspeaking,electronswithgreaterenergymoveinorbitalsfartherawayfromthenucleus.Foranelectrontojumpfromalowerorbitaltoahigherorbital,somethinghastoboostitsenergylevel.Conversely,anelectronreleasesenergywhenitdropsfromahigherorbitaltoalowerone.Thisenergyisreleasedintheformofaphoton.Agreaterenergydropreleasesahigher-energyphoton,whichischaracterizedbyahigherfrequency.Aswesawinthelastsection,freeelectronsmovingacrossadiodecanfallintoemptyholesfromtheP-typelayer.Thisinvolvesadropfromtheconductionbandtoalowerorbital,sotheelectronsreleaseenergyintheformofphotons.Thishappensinanydiode,butyoucanonlyseethephotonswhenthediodeiscomposedofcertainmaterial.Theatomsinastandardsilicondiode,forexample,arearrangedinsuchawaythattheelectrondropsarelativelyshortdistance.Asaresult,thephoton'sfrequencyissolowthatitisinvisibletothehumaneye--itisintheinfraredportionofthelightspectrum.Thisisn'tnecessarilyabadthing,ofcourse:InfraredLEDsareidealforremotecontrols,amongotherthings.Visiblelight-emittingdiodes(VLEDs),suchastheonesthatlightupnumbersinadigitalclock,aremadeofmaterialscharacterizedbyawidergapbetweentheconductionbandandthelowerorbitals.Thesizeofthegapdeterminesthefrequencyofthephoton--inotherwords,itdeterminesthecolorofthelight.Whilealldiodesreleaselight,mostdon'tdoitveryeffectively.Inanordinarydiode,thesemiconductormaterialitselfendsupalotofthelightenergy.LEDsarespeciallyconstructedtoreleasealargenumberofphotonsoutward.Additionally,theyarehousedinaplasticbulbthatconcentratesthelightinaparticulardirection.LEDshaveseveraladvantagesoverconventionalincandescentlamps.Foronething,theydon'thaveafilamentthatwillburnout,sotheylastmuchlonger.Additionally,theirsmallplasticbulbmakesthemalotmoredurable.Theyalsofitmoreeasilyintomodernelectroniccircuits.Butthemainadvantageisefficiency.Inconventionalincandescentbulbs,thelight-productionprocessinvolvesgeneratingalotofheat.Thisiscompletelywastedenergy,unlessyou'reusingthelampasaheater.LEDsgenerateverylittleheat,relativelyspeaking.Amuchhigherpercentageoftheelectricalpowerisgoingdirectlytogeneratinglight,whichcutsdownontheelectricitydemandsconsiderably.Upuntilrecently,LEDsweretooexpensivetouseformostlightingapplications.Thepriceofsemiconductordeviceshasplummetedoverthepastdecade,however,makingLEDsamorecost-effectivelightingoptionforawiderangeofsituations.Whiletheymaybemoreexpensivethanincandescentlightsupfront,theirlowercostinthelongruncanmakethemabetterbuy.Inthefuture,theywillplayanevenbiggerroleintheworldoftechnology.TRANSIENTVOLTAGESUPPRESSOR(TVS)DiodePRESENTATION?Highprotectiononsensitivemobileelectronicdevices?FollowstrictlytotheIEC61000-4-2ESDteststandard?UsingthebehaviorofdiodeP/NjunctiontoachieveESDprotectionWhatareTransientVoltages??Thesearefaultswhichcausethevoltagetogooutsidenormallimitsforaperiodoftime.Transientvoltagesarecharacterizedbythreethings:VeryHighVoltage,OccurForAVeryShortPeriodoftime(innanoseconds)andHighOccurrence.Manytransientscausedamagetomicro-semiconductorchipsetsbydegradingtheirperformance.Thisdamageiscumulativeandeventuallyreachesapointwheresuddenandcompletefailureofthecomponentresults.Moreover,sometransientsarecapableofcausingimmediateequipmentfailures.Equipmentfailurescausedbytransientsarehardtodetectandareoftenincorrectlyblamedonother‘perceived’causes.Microsemiconductorchipsetsdamagedbytransientsoftenrequiresophisticatedinstrumenttoreplacethemwhichmakethemexpensivetorepair.Theonlycureistoclamptransientstoasafelevelwheretheprotectedloadcanwithstand.TVSdiode’sAdvantages?TVSDiodevs.ZenerDiodeComparedwiththetraditionalZenerdiode,TVSdiodehasalargerP/Ncrosssection.TVSdiodecomponentisconstructedanddesignedtoabsorblargeramountsofenergy,joules,withafasterresponsetimethanZenerdiode.Zenerdiodehasahigherclampingvoltageandheatdissipationisslower.?TVSDiodevs.MultilayerMetaloxideVaristor,MLVAmajordifferencebetweenTVSdiodeandMLVis,asMLVabsorbstransientenergy,itselectricalparameterssuchasLeakagecurrentandBreakdownvoltagetendtodriftawayfromtheiroriginalspecificationswhichexhibitsaninherentwearoutmechanismwithinthestructure.Becauseofitshighimpedance,itsclampingratiocanreachashighas3.ThereforeMLVismoresuitabletobeappliedonlesssensitivelineswhereitshighclampingvoltagecanbetolerated.?TVSDiodevs.CeramicCapacitorCeramiccapacitorisnotabletowithstandahightransientvoltage.A10kVtransientvoltagewilldestroyabout60%ofthecomponentoftheceramiccapacitorwhileTVSdiodeisabletowithstandupto15Kvtransientvoltage.CeramiccapacitorisalsonotabletodissipateheatefficientlylikewhatTVSdiodedoeswhentransientoccurs.?TVSDiodevs.GasDischargeTubes,GDTsTVSdiodelimitsvoltagespiketoacceptablelevelbyclampingwhileGDTlimitsvoltagespikebycrowbaraction.GDTconductswhenitsthresholdvoltageisexceededandthentriggertoanon-statevoltageofonlyafewvolts.AdrawbackofGDTprotectionisthatthetriggeronstatevoltageisbelowtheoperatingvoltageoftheprotectedload.Theprotectedloadwillbeshutdowntemporarily.LED是如何工作的通常被稱為L(zhǎng)ED的發(fā)光二極管，是電子世界中真正的無名英雄。LED的功能多達(dá)幾十種，被廣泛的應(yīng)用于各種裝置之中。在其他應(yīng)用場(chǎng)合，LED可以作為數(shù)字鐘的數(shù)碼顯示、傳送來自遙控裝置的數(shù)據(jù)、手表的背光燈以及指示各種器械何時(shí)開啟。歸納起來，LED可以在巨大的電視熒屏上形成各種圖像或者點(diǎn)亮交通燈。從本質(zhì)上講，LED就是一