Niaj hnub nimno downlights vam meej ntawm LED technology. Kev tsiv teb tsaws loj heev rau LED teeb pom kev zoo feem ntau tau txhawb nqa los ntawm kev hloov pauv siab los ntawm hluav taws xob mus rau lub zog kho qhov muag thiab lub neej ntev ntawm LEDs. Phosphor hloov dua siab tshiab LEDs xa lub peev xwm ua tau zoo ntawm 255 lm / W thiab qhov ua tau zoo mus txog 200 lm / W, uas yog qhov siab dua li cov cuab yeej cuab tam halogen, fluorescent thiab hlau halide teeb. Thaum ua haujlwm LEDs nyob rau hauv ib puag ncig zoo thermally thiab hluav taws xob zoo, lawv L70 (70 feem pua lumen tu) lub neej tuaj yeem ntev li 200, 000 teev. Lub quantum leap hauv kev ua tau zoo thiab kev ntseeg tau yog los ntawm kev txhaj tshuaj electroluminescence hauv cov khoom siv semiconductor. Tshwj xeeb, cov neeg nqa khoom siv hluav taws xob los ntawm n-doped semiconductor txheej poob los ntawm cov khoom siv hluav taws xob thiab rov ua dua nrog qhov los ntawm qhov valence band ntawm p-doped semiconductor txheej hauv thaj tsam nquag ntawm lub diode, thaum muaj kev tsis ncaj ncees rau pem hauv ntej yog siv thoob plaws doped txheej. . Radiative recombination ntawm electrons thiab qhov tso tawm lub zog nyob rau hauv daim ntawv ntawm photons (packets ntawm lub teeb).
Txhaj electroluminescence nyob rau hauv lub active cheeb tsam ntawm lub semiconductor diode yields nqaim-band emission, ua rau ib tug xim lub teeb, xws li liab, xiav, ntsuab, los yog violet. Indium gallium nitride (InGaN), ib tug ncaj bandgap semiconductor, yog cov khoom ntawm kev xaiv rau kev tsim LED chips nrog siab quantum efficiency. Vim hais tias ntawm qhov nqaim spectral faib ntawm InGaN-raws li xiav lossis violet LEDs, lub wavelength converter yuav tsum tau hloov ib feem los yog tag nrho cov electroluminescence rau cov zis nrog ib tug dav emission profile, uas yog perceived li dawb lub teeb los ntawm tib neeg lub qhov muag. Qhov ua tau zoo tshaj plaws LEDs hnub no yog phosphor-hloov xiav InGaN LEDs, uas feem ntau hu ua xiav twj tso kua mis LEDs. Los ntawm kev siv ib lub teeb nqaim nqaim mus rau hauv phosphors ntawm cov khoom sib txawv hauv cov khoom siv, lub teeb dawb nrog cov spectral sib txawv tuaj yeem tsim tau.
Tailoring lub spectral fais fab faib (SPD) ntawm lub teeb dawb yog li tau yooj yim heev nrog LEDs. Lub SPD ntawm lub teeb ci qhia txog qhov muaj zog ntawm lub zog (lossis lub zog) tawm ntawm txhua lub wavelength. Nws tsim cov xim metrics ntawm lub teeb qhov chaw: xim rendition thiab xim tsos. Txij li cov LEDs muaj kev hloov pauv ntau dua rau kev kho SPD, LED downlights tuaj yeem tsim lub teeb nrog cov xim rendering kev ua tau zoo piv rau incandescent radiators thiab txawm tias ntuj nruab hnub ntawm txhua qhov sib txheeb xim kub (CCT). Qhov no yog qhov xav tau tshwj xeeb rau kev siv teeb pom kev zoo sab hauv, vim qhov xim zoo ntawm lub teeb ci cuam tshuam li cas tib neeg txaus siab rau ib qho khoom lossis ib puag ncig.
Lwm qhov txiaj ntsig tseem ceeb ntawm LEDs yog tias lawv tsim tsis muaj hluav taws xob infrared (IR) hluav taws xob thiab qhov tsis zoo ntawm ultraviolet (UV) emission (< 5="" uw/lm).="" ultraviolet="" and="" ir="" radiation="" can="" be="" very="" damaging="" to="" light-="" and="" heat-sensitive="" materials,="" such="" as="" museum="" artifacts,="" retail="" merchandise,="" and="" grocery="">
