Bifocal iav

Thaum tus neeg lub qhov muag hloov kho tsis muaj zog vim muaj hnub nyoog, nws yuav tsum kho nws lub zeem muag cais rau qhov pom deb thiab ze. Lub sijhawm no, nws feem ntau yuav tsum hnav ob lub tsom iav sib cais, uas yog qhov tsis yooj yim heev. Yog li ntawd, nws yog ib qho tsim nyog yuav tau zom ob lub zog sib txawv ntawm tib lub lens kom dhau los ua lo ntsiab muag hauv ob qhov chaw. Cov lo ntsiab muag zoo li no hu ua bifocal lo ntsiab muag lossis tsom iav bifocal.

Hom
Split hom
Nws yog qhov ntxov tshaj plaws thiab yooj yim tshaj plaws ntawm lub koob yees duab lens. Nws tus neeg tsim khoom feem ntau tau lees paub tias yog neeg Asmeskas nto moo Franklin. Ob lub lo ntsiab muag ntawm qhov sib txawv yog siv rau kev sib cais hom bifocal iav, uas yog siv los ua qhov deb thiab ze rau qhov chaw nruab nrab. Lub hauv paus ntsiab lus no tseem siv tau rau hauv txhua qhov kev tsim daim iav dual.

Gluing hom
Kaw lub sub-film mus rau lub ntsiab zaj duab xis. Cov pos hniav qub yog Canadian cedar cov pos hniav, uas yog ib qho yooj yim rau cov kua nplaum, thiab tseem tuaj yeem ua kua nplaum tom qab cov roj hmab yog degraded los ntawm txhua yam, thermal thiab tshuaj. Ib hom epoxy resin nrog kev ua tau zoo dua tom qab kev kho mob ultraviolet tau maj mam hloov cov qub. Daim iav bifocal nplaum ua rau cov qauv tsim thiab qhov loj ntawm sublayer ntau haiv neeg, nrog rau cov dyed sublayer thiab prism tswj tsim. Txhawm rau ua kom cov ciam teb pom tsis pom thiab tsis yooj yim rau kev kuaj pom, cov ntawv hlais tuaj yeem ua rau hauv lub voj voog, nrog rau qhov chaw kho qhov muag thiab qhov chaw geometric coincident. Waffle hom bifocal daim iav yog ib daim iav tshwj xeeb nplaum bifocal. Lub ntug tuaj yeem ua rau nyias nyias thiab nyuaj rau kev paub qhov txawv thaum lub sub-thooj ua tiav ntawm lub cev muaj zog ib ntus, yog li txhim kho qhov tsos.

Fusion hom
Nws yog los fuse cov khoom siv lens nrog siab refractive index mus rau hauv qhov chaw concave ntawm lub ntsiab phaj ntawm qhov kub thiab txias, thiab qhov refractive index ntawm lub ntsiab phaj yog tsawg. Tom qab ntawd khiav hauv qhov chaw ntawm lub sub-thooj kom qhov curvature ntawm sub-piece nto zoo ib yam nrog cov khoom tseem ceeb. Tsis muaj kev xav ntawm demarcation. Nyeem ntxiv A nyob ntawm lub zog refractive F1 ntawm sab pem hauv ntej ntawm qhov chaw deb ntawm lub zeem muag, curvature FC ntawm tus thawj concave arc thiab fusion piv. Qhov sib piv fusion yog qhov kev sib raug zoo ntawm qhov ntsuas qhov taw qhia ntawm ob theem fusion lens cov ntaub ntawv, qhov twg n sawv cev rau qhov ntsuas qhov ntsuas ntawm lub iav loj (feem ntau yog lub iav yas) thiab ns sawv cev rau qhov ntsuas qhov ntsuas ntawm cov ntawv sub (flint iav) nrog. tus nqi loj, ces tus fusion ratio k = (n-1) / (nn), ces A = (F1-FC) / k. Nws tuaj yeem pom los ntawm cov qauv saum toj no uas nyob rau hauv txoj kev xav, hloov lub hauv ntej ntawm lub ntsej muag curvature ntawm lub phaj loj, lub concave arc curvature thiab sub-phaj refractive index tuaj yeem hloov qhov ze ze ntxiv, tab sis qhov tseeb, nws yog feem ntau ua tiav los ntawm kev hloov. sub-phaj refractive index. Table 8-2 qhia qhov refractive index ntawm sub-daim ntawv flint iav feem ntau siv nyob rau hauv lub ntiaj teb no los tsim txawv ze-ntxiv fusion bifocal tsom iav.

Table 8-2 Refractive Performance index ntawm sub-phaj sib txawv ze-ntxiv fusion bifocal tsom iav (flint iav)