Ua ntej, lub luminous flux
Luminous flux yog hais txog tus nqi ntawm lub teeb tawm los ntawm lub teeb ci hauv ib lub sijhawm, uas yog, feem ntawm lub zog hluav taws xob uas lub zog hluav taws xob tuaj yeem pom los ntawm tib neeg lub qhov muag. Nws yog sib npaug rau cov khoom ntawm lub zog ntawm lub zog ntawm ib qho band ib lub sij hawm thiab qhov txheeb ze pom ntawm qhov band. Txij li qhov txheeb ze pom kev sib txawv ntawm qhov sib txawv wavelengths ntawm lub teeb los ntawm tib neeg lub qhov muag sib txawv, cov luminous fluxes tsis sib npaug thaum lub zog hluav taws xob ntawm qhov sib txawv wavelengths ntawm lub teeb sib npaug. Lub cim ntawm luminous flux yog Φ, chav tsev yog lumens (Lm)
Raws li spectral radiant flux Φ(λ), luminous flux formula tuaj yeem muab tau:
Φ=Km■Φ(λ)gV(λ)dλ
Hauv cov mis, V (λ) - txheeb ze spectral luminous efficiency; Km - tus nqi siab tshaj plaws ntawm spectral optical kev ua tau zoo ntawm hluav taws xob, nyob rau hauv units ntawm Lm / W. Tus nqi Km tau txiav txim los ntawm International Metrology Commission hauv 1977 kom yog 683 Lm/W (λm=555} nm).
Qhov thib ob, lub teeb siv
Lub teeb siv yog hais txog lub teeb lub zog dhau los ntawm ib cheeb tsam ntawm ib chav tsev ib lub sijhawm. Lub zog yog proportional rau lub zaus, uas yog cov sum ntawm lawv intensities (piv txwv li, integral). Nws tseem tuaj yeem nkag siab tias qhov luminous siv kuv ntawm lub teeb ci hauv ib qho kev taw qhia yog lub teeb ci. Lub quotient ntawm lub luminous flux dΦ kis tau nyob rau hauv cov khoom lub kaum sab xis nyob rau hauv cov kev taw qhia muab faib los ntawm cov khoom lub kaum sab xis dΩ
Chav tsev ntawm luminous siv yog candela (cd), 1 cd=1 Lm / 1 sr. Lub sum ntawm lub teeb nyob rau hauv tag nrho cov lus qhia ntawm qhov chaw yog lub luminous flux.
Thib peb, qhov ci ntsa iab
Nyob rau hauv tus txheej txheem ntawm kev ntsuam xyuas qhov ci ntawm LED chips thiab ntsuam xyuas kev nyab xeeb ntawm LED lub teeb hluav taws xob hluav taws xob, cov duab kos duab feem ntau yog siv, thiab microchip imaging tuaj yeem siv rau kev ntsuam xyuas nti. Qhov ci ntsa iab yog qhov ci ntsa iab L ntawm qee qhov taw tes ntawm lub teeb-emitting nto ntawm lub teeb ci, uas yog cov quotient ntawm lub teeb-emitting siv ntawm lub ntsej muag lub ntsiab dS nyob rau hauv ib tug muab kev taw qhia muab faib los ntawm orthographic cheeb tsam ntawm lub ntsej muag keeb nyob rau hauv ib lub dav hlau perpendicular mus rau ib qho kev taw qhia.
Chav tsev ntawm qhov ci yog candela ib square meter (cd / m2). Thaum lub teeb emitting nto yog perpendicular rau kev ntsuas kev taw qhia, ces cos θ=1.
Plaub, lub illuminance
Illuminance yog qib uas ib yam khoom yog illuminated, qhia nyob rau hauv cov nqe lus ntawm lub luminous flux tau txais ib chav tsev. Lub illuminance muaj feem xyuam rau txoj hauj lwm ntawm lub illumination qhov chaw, lub illuminated nto thiab lub teeb qhov chaw nyob rau hauv qhov chaw, thiab qhov loj yog proportional rau lub teeb siv ntawm lub teeb qhov chaw thiab qhov teeb meem ntawm lub teeb, thiab inversely proportional rau lub square ntawm. qhov kev ncua deb ntawm lub teeb qhov chaw mus rau saum npoo ntawm cov khoom illuminated. Lub teeb pom kev zoo E ntawm qhov taw tes ntawm qhov chaw yog qhov quotient ntawm luminous flux dΦ teeb meem ntawm lub vaj huam sib luag nrog rau qhov taw tes faib los ntawm thaj tsam vaj huam sib luag dS.
Chav tsev yog lux (LX), 1LX=1Lm/m2.
