LED調(diào)光控制論文中英文資料對(duì)照外文翻譯文獻(xiàn)綜述

LED調(diào)光控制及優(yōu)點(diǎn)中英文資料對(duì)照外文翻譯文獻(xiàn)綜述附錄1譯文LED的調(diào)光是利用一個(gè)DC信號(hào)或?yàn)V液PWM對(duì)LED中的正向電流進(jìn)行調(diào)節(jié)來完成的。減小LED電流將起到調(diào)節(jié)LED光輸出強(qiáng)度的作用，然而，正向電流的變化也會(huì)改變LED的彩色，因?yàn)長(zhǎng)ED的色度會(huì)隨著電流的變化而變化。許多應(yīng)用（例如汽車和LCDTV背光照明）都不能允許LED發(fā)生任何的色彩漂移。在這些應(yīng)用中，由于周圍環(huán)境中存在不同的光線變化，而且人眼對(duì)于光強(qiáng)的微小變化都很敏感，因此寬范圍調(diào)光是必需的。通過施加一個(gè)PWM信號(hào)來控制LED亮度的做法允許不改變彩色的情況下完成LED的調(diào)光。人們常說的真正彩色（TrueColor）PWM調(diào)光是利用一個(gè)PWM信號(hào)來調(diào)節(jié)LED的亮度。調(diào)節(jié)LED亮度有三種常用方法：（1）使用SET電阻，在LED驅(qū)動(dòng)控制IC引腳RSET兩端并聯(lián)不同的轉(zhuǎn)換電阻，使用一個(gè)直流電壓設(shè)置LED驅(qū)動(dòng)控制IC引腳RSET的電流，從而改變LED的正向工作電流，達(dá)到調(diào)節(jié)ALED發(fā)光亮度的目的。（2）采用PWM技術(shù)，利用PWM控制信號(hào)，通過控制LED的正向工作電流的占空比來調(diào)節(jié)ALED的發(fā)光亮度。（3）線性調(diào)節(jié)-1-最簡(jiǎn)便的方法是在LED驅(qū)動(dòng)控制C中使用外部SET電阻來實(shí)現(xiàn)LED的調(diào)光控制。雖然，這種調(diào)光控制方法有效，但卻缺乏靈活性，無法讓用戶改變光強(qiáng)度。線性調(diào)節(jié)則會(huì)降低效率，并引起白光LED朝向黃色光譜的色彩偏移?？赡苁禽p微的偏移，但可在敏感應(yīng)用中檢測(cè)出。采用數(shù)字或叫PWM的LED調(diào)光控制法以大于100HZ的開關(guān)工作頻率，以脈寬調(diào)制的方法改變LED驅(qū)動(dòng)電流的脈沖占空比來實(shí)理LED的調(diào)光控制，選用大于100HZ開關(guān)調(diào)光控制頻率主要是為了避免人眼感覺到調(diào)光閃爍現(xiàn)象，在LED的PWM調(diào)光控制下，LED的發(fā)光亮度正比于PWM的脈沖占空比，在這種調(diào)光控制方法下，可以在高度調(diào)光比范圍內(nèi)保持LED的發(fā)光顏色不變，采用PWM的LED調(diào)光控制的調(diào)光比范圍可達(dá)3000：1。線性LED調(diào)光控制方法就是采用模擬調(diào)光控制方法，在模擬調(diào)光控制下，通過調(diào)節(jié)LED的正向工作電流來實(shí)現(xiàn)LED的調(diào)光控制，調(diào)光控制范圍可達(dá)10：1。如果要進(jìn)一步降低LED的正向工作電流則會(huì)產(chǎn)生LED發(fā)光顏色發(fā)生變化和不能準(zhǔn)確調(diào)節(jié)控制LED的正向工作電流的問題。LED作為一種新型照明器件的優(yōu)點(diǎn)如下：1．節(jié)能：發(fā)光二極管比標(biāo)準(zhǔn)燈泡更節(jié)省能源，大大降低了能源費(fèi)用。發(fā)光二極管還比其它光源在生產(chǎn)時(shí)所需更少能源，減少對(duì)環(huán)境的影響。2．壽命長(zhǎng)：發(fā)光二極管的典型工作壽命為100000小時(shí)，也就是說11.5年，絕大多數(shù)白熾燈泡在用幾千小時(shí)之后就到達(dá)盡頭了。3斷了。而發(fā)光二極管則沒有玻璃或燈絲會(huì)折斷，所以使發(fā)光二極管在苛求的環(huán)境或安裝困難成為完美的光源。4大的減少成本。低功率消耗，壽命長(zhǎng)和它的可靠性減少了維修成本，尤其是在那睦大量安裝的情況下。5能源消耗起了很大幫助。發(fā)光二極管不僅僅在生產(chǎn)上所需的能源和材料少它還不含有在熒光燈里常見的有毒物質(zhì)水銀。6加安全的光源。7LED可見光通訊技術(shù)的優(yōu)點(diǎn),在於可避免一般WLAN或高頻無線傳輸?shù)碾姶挪?對(duì)人體與周邊電子設(shè)備造成干擾的影響,并可取代無線基地臺(tái),-2-同時(shí)具備安全性高的特點(diǎn)。目前許多業(yè)界、標(biāo)準(zhǔn)組織,或者得到政府資助的計(jì)劃都開始研發(fā)LED可見光通訊,其前景十分被看好。畢竟僅傳統(tǒng)照明市場(chǎng)的規(guī)模便達(dá)到數(shù)兆美元,未來過渡到固態(tài)照明市場(chǎng),其商機(jī)十分可觀。附錄2英文參考資料theTraditionally,LEDlighttoneofthefiltrateusingaDCsignalorthePWMontheLEDforwardcurrentregulationtocomplete.ReducetheLEDcurrentwillplayaregulatoryroleofLEDlightoutputintensity,however,changesinforwardcurrentLEDwillchangecolor,becausetheLED'scolorwillchangewiththecurrentchanges.Manyapplications(suchasautomotiveandLCDTVbacklight)arenotallowedanyLEDcolordrift.Intheseapplications,therearedifferentduetothesurroundingenvironment,lightchanges,andthehumaneyetosmallchangesinintensityaresensitivetoawiderangedimmingisrequired.ByapplyingaPWMsignaltocontrolLEDbrightnessdoesnotchangethepracticeofallowingthecasetocompletecolorLEDdimming.Peopleoftensaythatthetruecolor(TrueColor)PWMdimmingusingaPWMsignaltoadjusttheLEDbrightness.AdjusttheLEDbrightness,therearethreecommonmethods:(1)theuseofSETresistance,theLEDdrivercontrolICpinRSETbothendsoftheparallelconversionofdifferentresistancesettingsusingaDCvoltageLEDdrivercontrolICpinRSETcurrent,therebychangingtheLED'sforwardcurrent,toadjusttheALEDThepurposeofbrightness.(2)usingPWMtechniques,theuseofPWMcontrolsignals,bycontrollingtheLED'sforwardoperatingcurrenttoadjustthedutycycleALEDluminance.-3-(3)linearregulatorTheeasiestwayistocontroltheLEDdriveC,usingexternalresistorstoachievetheSETLEDdimmingcontrol.Although,thisdimmingcontrolmethodiseffective,butthelackofflexibility,cannotallowuserstochangethelightintensity.LinearregulatorwillreduceefficiencyandcausewhiteLEDcolorshifttowardtheyellowspectrum.Maybeslightlyoffset,butcanbedetectedinsensitiveapplications.CalleddigitalorPWMdimmingcontrolmethodoftheLEDtoswitchover100HZfrequency,pulsewidthmodulationmethodtochangetheLEDdrivecurrentpulsedutycycletoimplementmanagementLEDdimmingcontrol,thechoiceofswitchingtonethan100HZLightcontrolfrequencyismainlyfeltinordertoavoiddimmingeyesflickerintheLED'sunderthecontrolofPWMdimming,LED'sbrightnessisproportionaltothePWMpulsedutycycle,inwhichthedimmingcontrolmethod,itcanbeinahighlymaintainthantherangeofdimmingLED'slightcolorchange,theuseofPWMdimmingcontrolofLEDdimmingratiorangeofupto3000:1.LinearLEDdimmingcontrolmethodistouseanalogdimmingcontrolmethod,inanalogdimmingcontrol,byadjustingtheLED'sforwardworktoachieveLEDcurrentdimmingcontrol,dimmingcontrolofupto10:1.IfyouwanttoworktofurtherreducetheLEDcurrentwillproduceapositivecolorchangeLEDlightandcannotaccuratelyworkofregulationandcontrolLEDcurrentissueforward.AsanewtypeofLEDlightingdevicehasthefollowingadvantages:1energy-saving:LEDbulbssavemoreenergythanthestandard,whichgreatlyreducesenergycosts.Thanotherlightsourcesemittingdiodeisalsorequiredintheproductionoflessenergyandreduceenvironmentalimpact.2．longlife:thetypicalLEDlifeof100,000hoursofwork,thatis11.5years,mostincandescentlightbulbsinusethousandsofhourstoreachanend.3．Reliability:normallightbulbfilamentisveryfragileobjects,vibration,veryeasytolookbroken.Thelight-emittingdiodeswillbenoglassorfilamenttobreak,sothelight-emittingdiodesinstalledinthedemandingenvironmentordifficultastheperfectsource.4．theeconomy:Despiteitsinitialpriceishigh,buttheuseofLEDlightinginseveralareascangreatlyreducecosts.Lowpowerconsumption,longlifeand-4-reliabilityofitsreducedmaintenancecosts,especiallyinthatcaseofinstallingalargenumberofMu.5．a(chǎn)ndenvironment-friendly:WhileglobalwarmingbygrowingconcernaboutLEDlightingtoreduceenergyconsumptionplayedagreathelp.LEDsnotonlyinproductionlessenergyandmaterialsneededtocontainitisnotoftenseeninthefluorescentlampmercurytoxicsubstances.6．bettersecurity:thelight-emittingdiodeswithlowheatandlowvoltagerequirementsmakeitamoresecuresource.7．LEDvisiblelightcommunicationtechnology,theadvantagesisthatitcanavoidthegeneralWLANorwirelesstransmissionofhighfrequencyelectromagneticwaves,onthehumanbodyandsurroundingtheimpactofinterferencetoelectronicequipment,andreplacethewireles