Idan daidaitawar idon mutum ya raunana saboda tsufa, yana buƙatar gyara hangen nesa daban don hangen nesa da kusa. A wannan lokacin, shi / ta sau da yawa yana buƙatar sanya nau'i-nau'i biyu na tabarau daban, wanda ba shi da kyau. Don haka, ya zama dole a niƙa mabambantan iko guda biyu a kan ruwan tabarau ɗaya don zama ruwan tabarau a wurare biyu. Ana kiran irin wannan ruwan tabarau na bifocal ko gilashin bifocal.
Nau'in
Nau'in Raba
Shine nau'in ruwan tabarau na farko kuma mafi sauƙi. Gabaɗaya an san wanda ya ƙirƙira shi a matsayin shahararren ɗan Amurka Franklin. Ana amfani da ruwan tabarau biyu na digiri daban-daban don nau'in nau'in madubi na bifocal, waɗanda ake amfani da su azaman wurare masu nisa da kusa don matsawa ta tsakiya. Har yanzu ana amfani da wannan ƙa'idar a cikin duk ƙirar madubi biyu.
Nau'in manne
Manna ƙaramin fim ɗin akan babban fim ɗin. Asalin danko shine ɗan itacen al'ul na Kanada, wanda ke da sauƙin mannewa, kuma ana iya manne shi bayan da roba ya lalace ta hanyar injina, zafi da sinadarai. Wani nau'in resin epoxy tare da ingantaccen aiki bayan jiyya na ultraviolet ya maye gurbin na farko a hankali. Mudubin bifocal mai manne yana sa nau'in ƙira da girman sublayer ya bambanta, gami da rini da ƙirar ƙirar priism. Don yin iyakar da ba a iya gani da wuya a gano shi, za a iya yin ƙananan yanki a cikin da'irar, tare da cibiyar gani da cibiyar geometric daidai. Waffle nau'in madubi bifocal madubi ne na musamman manne. Za'a iya sanya gefen sirara sosai kuma yana da wahalar rarrabewa lokacin da ake sarrafa ƙaramin yanki akan jikin ɗan lokaci mai ɗaukar nauyi, don haka inganta bayyanar.
Nau'in Fusion
Shi ne don haɗa kayan ruwan tabarau tare da babban maƙasudin refractive zuwa cikin madaidaicin wuri a kan babban farantin a babban zafin jiki, kuma fihirisa mai jujjuyawa na babban farantin yana da ƙasa. Sa'an nan kuma gudu a cikin farfajiyar ƙananan yanki don yin lanƙwasa na ƙananan yanki daidai da na babban yanki. Babu ma'anar shata. Karatuttukan ƙarin A ya dogara ne da ikon jujjuyawar F1 na farfajiyar gaba na filin hangen nesa, curvature FC na ainihin madaidaicin baka da rabon fusion. Matsakaicin fusion shine alaƙar aiki tsakanin ma'anar refractive na kayan ruwan tabarau na lokaci biyu, inda n ke wakiltar ma'auni mai jujjuyawa na babban gilashin (yawanci gilashin rawanin) kuma ns yana wakiltar ma'anar refractive na ƙaramin takarda (gilashin flint) tare da babban darajar, to, fusion rabo k=(n-1) / (nn), don haka A = (F1-FC) / k. Ana iya gani daga wannan dabarar da ke sama cewa a ka'idar, canza yanayin gaban gaban babban farantin, madaidaicin arc da ginshiƙan faranti na iya canza ƙarin digiri na kusa, amma a zahiri, ana samun gabaɗaya ta hanyar canzawa. ma'anar refractive sub-platet. Tebur 8-2 yana nuna ma'aunin gilashin ƙaramin takarda da aka saba amfani da shi a cikin duniya don kera nau'ikan madubin haɗin fuska daban-daban.
Tebura 8-2 Fihirisar nuni na ƙananan faranti daban-daban na ƙarin madubin haɗin fuska na kusa (gilashin dutse)
Rabon juzu'i mai jujjuyawa na ƙarin ƙaramin faranti
+0.50 ~ 1.251.5888.0
+1.50 ~ 2.751.6544.0
+3.00~+4.001.7003.0
Yin amfani da hanyar haɗakarwa, ana iya yin ƙananan guntu masu siffa na musamman, kamar ƙananan guntuwar saman lebur, guntun guntun baka, guntun guntun bakan gizo, da dai sauransu. Idan muka yi amfani da fihirisar refractive na uku, za mu iya yin fused ɗin madubi mai katako guda uku. .
Binoculars na guduro wani binocular na haɗe ne da aka kera ta hanyar simintin gyare-gyare. Fusion bifocal madubi an yi su da kayan gilashi. Gilashin haɗaɗɗen madubin bifocal yana buƙatar fasahar niƙa mafi girma.
Nau'in E-nau'in layi ɗaya haske biyu
Irin wannan madubi mai haske biyu yana da babban wurin kusanci. Wani nau'i ne na madubi mai haske biyu mara hoto, wanda za'a iya yin shi da gilashi ko guduro. A haƙiƙa, madubi bifocal nau'in E-nau'in za a iya la'akari da shi azaman mummunan mataki na ƙarin hangen nesa akan madubin kusanci. Kauri na babba rabin gefen ruwan tabarau yana da girma sosai, don haka kauri na babba da ƙananan gefuna na ruwan tabarau na iya zama iri ɗaya ta hanyar priism thinning. Girman prism ɗin tsaye da aka yi amfani da shi ya dogara da ƙari kusa, wanda shine yA/40, inda y shine nisa daga layin rarraba zuwa saman takardar, kuma A shine ƙarar karatu. Tun da kusa da abin da aka makala na idanu biyu yawanci daidai ne, adadin bakin ciki na priism na binocular shima iri ɗaya ne. Bayan an ɓata firam ɗin, za a ƙara ko rage fim ɗin don kawar da refraction na ciki.
Lokacin aikawa: Maris-09-2023