Muaj cov khoom uas muaj peev xwm hloov qhov ceev ntawm cov hluav taws xob hluav taws xob hluav taws xob hluav taws xob poob rau ntawm lawv, uas yog, ua kom nws los ntawm kev sib sau ntawm ib qho, lossis txo nws los ntawm kev tawg. Cov khoom no hu ua lo ntsiab muag hauv physics. Cia wb mus saib qhov teeb meem no.
Lens yog dab tsi hauv physics?
Lub tswv yim no txhais tau tias yog txhua yam khoom uas muaj peev xwm hloov cov kev taw qhia ntawm kev nthuav tawm ntawm hluav taws xob hluav taws xob. Qhov no yog lub ntsiab txhais ntawm lo ntsiab muag nyob rau hauv physics, uas muaj xws li optical tsom iav, magnetic thiab gravitational lo ntsiab muag.
Nyob rau hauv tsab xov xwm no, qhov kev tsom xam yuav yog ntawm cov iav kho qhov muag, uas yog cov khoom ua los ntawm cov khoom pob tshab thiab txwv los ntawm ob qhov chaw. Ib qho ntawm cov chaw no yuav tsum muaj qhov curvature (uas yog, ua ib feem ntawm lub vojvoog ntawm qhov kawg), txwv tsis pub cov khoom yuav tsis muaj cov cuab yeej hloov pauv cov kev taw qhia ntawm kev nthuav tawm ntawm lub teeb rays.
Lub ntsiab lus ntawm lub lens
Lub ntsiab ntawm kev ua haujlwm ntawm qhov tsis sib xwsoptical object yog qhov tshwm sim ntawm refraction ntawm lub hnub rays. Thaum pib ntawm lub xyoo pua 17th, tus naas ej Dutch physicist thiab astronomer Willebrord Snell van Rooyen luam tawm txoj cai ntawm refraction, uas tam sim no dais nws lub xeem lub npe. Lub formulation ntawm txoj cai no yog raws li nram no: thaum tshav ntuj dhau los ntawm lub interface ntawm ob optically pob tshab xov xwm, ces cov khoom ntawm lub sine ntawm lub kaum sab xis ntawm qhov tshwm sim ntawm lub beam thiab qhov ib txwm mus rau qhov chaw thiab lub refractive index ntawm nruab nrab nyob rau hauv uas. nws propagates yog tus nqi tas mus li.
Kom qhia meej cov lus saum toj no, cia peb ua piv txwv: cia lub teeb poob rau saum npoo dej, thaum lub kaum sab xis ntawm qhov qub rau saum npoo thiab kab teeb yog θ 1. Tom qab ntawd, lub teeb beam yog refracted thiab pib nws propagation nyob rau hauv dej twb nyob rau ntawm ib tug kaum sab xis θ2 mus rau qhov qub rau saum npoo. Raws li Snell txoj cai, peb tau txais: sin(θ1)n1=sin(θ2) n2, qhov twg n1 thiab n2 yog qhov ntsuas ntsuas huab cua thiab dej, raws. Dab tsi yog qhov refractive index? Qhov no yog tus nqi uas qhia tias muaj pes tsawg zaus ntawm qhov ceev ntawm kev nthuav tawm ntawm electromagnetic nthwv dej hauv lub tshuab nqus tsev yog ntau dua li qhov nruab nrab ntawm optically pob tshab, uas yog, n=c / v, qhov twg c thiab v yog qhov ceev ntawm lub teeb hauv lub tshuab nqus tsev thiab nyob rau hauv qhov chaw. nruab nrab, feem.
Lub physics ntawm qhov pom ntawm refraction yog nyob rau hauv kev ua raws ntawm Fermat lub hauv paus ntsiab lus, raws li lub teeb txav mus rau hauv txoj kev kom kov yeej qhov kev ncua deb ntawm ib qho taw tes mus rau lwm qhov hauv qhov chaw hauv lub sijhawm luv tshaj.
hom lo ntsiab muag
hom optical lens hauv physics tsuas yog txiav txim siab los ntawm cov duab ntawm qhov chaw uas tsim nws. Cov kev taw qhia ntawm refraction ntawm cov teeb meem beam ntawm lawv nyob ntawm qhov zoo li no. Yog li, yog tias qhov curvature ntawm qhov chaw yog qhov zoo (convex), ces, thaum tawm ntawm lub lens, lub teeb beam yuav propagate los ze zog rau nws optical axis (saib hauv qab). Hloov pauv, yog tias qhov curvature ntawm qhov chaw tsis zoo (concave), tom qab ntawd dhau los ntawm cov iav kho qhov muag, lub nqaj yuav txav deb ntawm nws qhov nruab nrab axis.
Nco ntsoov rov qab tias qhov chaw ntawm txhua qhov curvature refracts rays tib yam (raws li Stella txoj cai), tab sis qhov ib txwm muaj rau lawv muaj qhov sib txawv ntawm txoj kab nqes mus rau qhov chaw kho qhov muag, uas ua rau muaj kev sib txawv ntawm cov duab hluav taws xob refracted.
Lub lens uas muaj ob lub convex nto yog hu ua converging lens. Nyob rau hauv lem, yog hais tias nws yog tsim los ntawm ob qhov chaw nrog tsis zoo curvature, ces nws yog hu ua scattering. Tag nrho lwm yam ntawm cov iav kho qhov muag yog txuam nrog kev sib xyaw ua ke ntawm cov chaw no, uas muaj lub dav hlau ntxiv. Yam khoom dab tsi uas lub lens ua ke yuav muaj (divergent lossis converging) nyob ntawm tag nrho curvature ntawm radii ntawm nws qhov chaw.
Lens ntsiab thiab ray properties
txhawm rau tsim cov lo ntsiab muag hauv cov duab physics, koj yuav tsum tau paub txog cov ntsiab lus ntawm cov khoom no. Lawv muaj npe hauv qab no:
- Lub qhov muag qhov muag loj thiab qhov nruab nrab. Nyob rau hauv thawj rooj plaub, lawv txhais tau hais tias ib txoj kab ncaj nraim mus rau lub lens los ntawm nws qhov chaw kho qhov muag. Qhov kawg, tig mus, yog ib qho taw tes hauv lub lens, dhau los ntawm cov nqaj tsis muaj qhov cuam tshuam.
- Focal ntev thiab ua kom pom tseeb - qhov kev ncua deb ntawm qhov chaw nruab nrab thiab ib qho taw qhia ntawm qhov chaw kho qhov muag, uas sau tag nrho cov teeb meem ntawm lub teeb ntawm lub lens sib npaug mus rau qhov axis. Qhov kev txhais no muaj tseeb rau kev sau cov iav kho qhov muag. Nyob rau hauv cov ntaub ntawv ntawm divergent lo ntsiab muag, nws tsis yog lub rays lawv tus kheej uas yuav converge mus rau ib tug taw tes, tab sis lawv cov kev xav mus ntxiv. Lub ntsiab lus no hu ua lub ntsiab tseem ceeb.
- Optical zog. Qhov no yog lub npe ntawm qhov sib txuam ntawm qhov ntev, uas yog, D \u003d 1 / f. Nws yog ntsuas hauv diopters (diopters), uas yog, 1 diopter.=1 m-1.
Cov hauv qab no yog cov khoom tseem ceeb ntawm cov rays uas dhau los ntawm lub lens:
- nqaj hla dhau qhov chaw kho qhov muag tsis hloov nws txoj kev taw qhia;
- rays xwm txheej thaum uas tig mus rau lub ntsiab kho qhov muag axis hloov lawv cov kev taw qhia kom lawv dhau los ntawm lub ntsiab tsom;
- rays ntog ntawm cov iav kho qhov muag ntawm txhua lub kaum ntse ntse, tab sis dhau los ntawm nws txoj kev tsom mus rau, hloov lawv cov kev taw qhia ntawm kev nthuav tawm nyob rau hauv ib txoj kev uas lawv ua tib yam rau lub ntsiab kho qhov muag axis.
Cov khoom saum toj no ntawm cov duab hluav taws xob rau cov lo ntsiab muag nyias hauv physics (raws li lawv raug hu vim tias tsis muaj teeb meem dab tsi lawv tau tsim thiab tuab npaum li cas, tsuas yog cov khoom kho qhov muag ntawm cov khoom teeb meem) yog siv los tsim cov duab hauv lawv..
Cov duab hauv tsom iav qhov muag: yuav ua li cas?
Hauv qab no yog ib daim duab uas qhia txog cov tswv yim tsim cov duab hauv lub qhov muag thiab lub qhov muag ntawm ib qho khoom(xov liab) nyob ntawm nws txoj hauj lwm.
Cov lus xaus tseem ceeb ua raws los ntawm kev txheeb xyuas ntawm cov circuits hauv daim duab:
- Ib daim duab yog tsim los ntawm 2 rays nkaus xwb (dhau los ntawm qhov chaw thiab sib npaug mus rau lub ntsiab kho qhov muag axis).
- Converging lo ntsiab muag (suav nrog cov xub ntawm qhov kawg taw tes rau sab nraud) tuaj yeem muab ob qho tib si nthuav dav thiab txo cov duab, uas tuaj yeem ua tau tiag tiag (tiag tiag) lossis kev xav.
- Yog tias qhov khoom nyob hauv qhov tsom, ces lub lens tsis tsim nws cov duab (saib daim duab qis dua ntawm sab laug hauv daim duab).
- Cov tsom iav kho qhov muag (suav los ntawm cov xub ntawm lawv qhov kawg taw qhia sab hauv) ib txwm muab cov duab txo qis thiab virtual tsis hais qhov chaw ntawm qhov khoom.
Nrhiav qhov deb ntawm ib daim duab
Txhawm rau txiav txim siab nyob deb npaum li cas cov duab yuav tshwm sim, paub txog txoj haujlwm ntawm qhov khoom nws tus kheej, peb muab lub lens mis hauv physics: 1/f=1/do + 1 /d i, qhov twg do thiab di yog qhov deb ntawm qhov khoom thiab rau nws cov duab los ntawm qhov muag pom. center, ntsig txog, f yog lub ntsiab tseem ceeb. Yog tias peb tab tom tham txog kev khaws cov iav kho qhov muag, ces tus naj npawb f yuav zoo. Hloov pauv, rau lub lens divergent, f yog qhov tsis zoo.
Cia peb siv cov qauv no thiab daws qhov teeb meem yooj yim: cia cov khoom nyob deb do=2f los ntawm qhov nruab nrab ntawm cov iav ntim khoom. Nws daim duab yuav tshwm rau qhov twg?
Los ntawm qhov teeb meem peb muaj: 1/f=1/(2f)+1/di. From: 1/di=1/f - 1/(2f)=1/(2f), i.e. di=2 f. Yog li, cov duab yuav tshwm sim ntawm qhov deb ntawm ob foci ntawm lub lens, tab sis nyob rau sab nraud tshaj qhov khoom nws tus kheej (qhov no yog qhia los ntawm qhov zoo ntawm tus nqi di).
A Brief History
Nws xav paub muab lo lus etymology ntawm lo lus "lens". Nws los ntawm lo lus Latin lo lus lo ntsiab muag thiab lentis, uas txhais tau tias "lentil", txij li cov khoom siv kho qhov muag hauv lawv cov duab tiag tiag zoo li cov txiv hmab txiv ntoo ntawm cov nroj tsuag no.
Lub zog refractive ntawm lub cev pob tshab pob tshab tau paub rau cov neeg Loos thaum ub. Rau lub hom phiaj no, lawv siv cov iav raj ntim nrog dej. Cov iav lo ntsiab muag lawv tus kheej tau pib ua tsuas yog nyob rau xyoo pua 13th hauv Tebchaws Europe. Lawv tau siv los ua cov cuab yeej nyeem ntawv (cov iav niaj hnub lossis iav tsom iav).
Kev siv cov khoom siv kho qhov muag hauv kev tsim lub koob yees duab thiab lub tshuab tsom iav hnub rov qab mus rau xyoo pua 17th (thaum pib ntawm lub xyoo pua no, Galileo tau tsim thawj lub koob yees duab). Nco ntsoov tias kev tsim lej ntawm Stella txoj cai ntawm kev cuam tshuam, tsis muaj kev paub txog qhov uas nws tsis tuaj yeem tsim cov lo ntsiab muag nrog cov khoom xav tau, tau luam tawm los ntawm tus kws tshawb fawb Dutch thaum pib ntawm tib lub xyoo pua 17th.
Lwm lo ntsiab muag
Raws li tau sau tseg saum toj no, ntxiv rau cov khoom siv kho qhov muag, kuj tseem muaj cov khoom sib nqus thiab gravitational. Ib qho piv txwv ntawm yav dhau los yog cov lo ntsiab muag sib nqus nyob rau hauv ib lub tshuab hluav taws xob electron, ib qho piv txwv zoo ntawm qhov tom kawg yog qhov cuam tshuam ntawm kev taw qhia ntawm lub teeb flux,thaum nws dhau los ze lub cev loj heev (hnub qub, ntiaj chaw).
