Nigute wagabanya urusaku rwamafoto

Nigute wagabanya urusaku rwamafoto

Urusaku rwa Photodetector rurimo cyane cyane: urusaku rwubu, urusaku rwumuriro, urusaku rwamasasu, urusaku rwa 1 / f n urusaku rwagutse, nibindi. Iri tsinda ni rimwe gusa. Iki gihe, tuzamenyekanisha ibisobanuro birambuye byurusaku nibisobanuro kugirango dufashe buriwese gusobanukirwa neza ningaruka zubwoko butandukanye bwurusaku kubimenyetso bisohoka bya fotodektor. Gusa twunvise inkomoko yurusaku dushobora kurushaho kugabanya no kunoza urusaku rwamafoto, bityo tugahindura igipimo cyerekana-urusaku rwa sisitemu.

Urusaku rw'amasasu ni ihindagurika ridasanzwe ryatewe na kamere yihariye yabatwara ibicuruzwa. Cyane cyane mubikorwa bya fotoelectric, mugihe fotone ikubise ibice byamafoto kugirango bibyare electron, ibisekuruza bya electroni ntibisanzwe kandi bihuye no gukwirakwiza Poisson. Ibiranga urusaku rwamasasu birasa kandi bitigenga ubunini bwinshyi, bityo rero byitwa urusaku rwera. Imibare isobanura: Imizi isobanura kare (RMS) agaciro k'urusaku rw'amasasu irashobora kugaragazwa nka:

Muri bo:

e: Amafaranga ya elegitoronike (hafi 1,6 × 10-19 coulombs)

Ikimenyetso: Umuyoboro wijimye

Δf: Umuyoboro mugari

Urusaku rw'amasasu ruringaniye n'ubunini bwubu kandi ruhagaze kuri frequence zose. Muri formula, Idark yerekana umwijima wijimye wa fotodiode. Nukuvuga ko, mugihe hatabonetse urumuri, fotodiode ifite urusaku rwijimye rudashaka. Nka rusaku rwarimbere kuruhande rwimbere rwa fotodetekeri, nini nini yumwijima, niko urusaku rwamafoto. Umuyoboro wijimye nawo wibasiwe na bias ikora voltage ya fotodiode, ni ukuvuga, uko nini ya bias ikora voltage, niko umwijima wijimye. Nyamara, kubogama gukora kubogamye nabyo bigira ingaruka kumikorere ya fotodetector, bityo bikagira ingaruka kumuvuduko no kwaguka kwifoto. Byongeye kandi, uko kubogama kubogamye, niko umuvuduko mwinshi. Kubwibyo, kubijyanye nurusaku rwamasasu, umwijima wijimye hamwe numuyoboro mugari wa fotodiode, igishushanyo mbonera kigomba gukorwa ukurikije umushinga usabwa.

2. 1 / f Urusaku rwihuta

Urusaku 1 / f, ruzwi kandi nk'urusaku rwa flicker, cyane cyane ruba mu ntera ntoya kandi bifitanye isano nibintu nk'utunenge twibintu cyangwa isuku yo hejuru. Uhereye ku gishushanyo mbonera cyacyo kiranga, birashobora kugaragara ko imbaraga zayo zerekana ko ari ntoya cyane mu ntera ndende kuruta iyo mu ntera ntoya, kandi kuri buri nshuro 100 kwiyongera inshuro, urusaku rw’ubucucike rugabanuka ku buryo bugaragara inshuro 10. Imbaraga zerekana imbaraga za 1 / f urusaku ruringaniye na frequency, ni:

Muri bo:

SI (f): Urusaku rwimbaraga zerekana

I: Ibiriho

f: Inshuro

Urusaku 1 / f ni ingirakamaro mu ntera ntoya kandi igabanuka uko inshuro ziyongera. Ibiranga bituma iba isoko yingenzi yo kwivanga mubikorwa bike-bya porogaramu. Urusaku 1 / f n urusaku rwumuvuduko mugari ahanini biva mumajwi ya voltage ya amplifier ikora imbere muri Photodetector. Hariho andi masoko menshi y’urusaku agira ingaruka ku rusaku rwa fotodetekeri, nk'urusaku rutanga amashanyarazi ya amplificateur ikora, urusaku ruriho, hamwe n'urusaku rw'ubushyuhe bw'urusobe rurwanya kugira ngo habeho imiyoboro ikora.

3. Umuvuduko n urusaku rwubu rwibikorwa byongera imbaraga: Umuvuduko nubucucike bwikurikiranwa byerekanwe mubishusho bikurikira:

Mubikorwa bya amplifier ikora, urusaku rwubu rugabanijwemo urusaku rwicyiciro cya none no guhinduranya urusaku rwubu. Urusaku rwicyiciro cya none i + rutemba ruva mumasoko arwanya imbere imbere, kubyara urusaku rungana na u1 = i + * amafaranga. I. Kubwibyo, kugirango urusaku rwiza, urusaku rwo gutanga amashanyarazi (harimo no kurwanya imbere) nabwo ni icyerekezo cyingenzi cyo gukora neza. Ubucucike bwurusaku rwubu ntabwo bihinduka hamwe ninshuro zitandukanye. Kubwibyo, nyuma yo kongererwa imbaraga numuzunguruko, ni, nkumuyaga wijimye wa fotodiode, ikora byimazeyo urusaku rwamafoto ya fotodektor.

4. Urusaku rwumuriro rwumuyoboro urwanya inyungu (amplification factor) yumuzunguruko wa amplifier ukora urashobora kubarwa ukoresheje formula ikurikira:

Muri bo:

k: Boltzmann ihoraho (1.38 × 10-23J / K)

T: Ubushyuhe Bwuzuye (K)

R. Birashobora kugaragara uhereye kuri formula ko uko inyungu zunguka agaciro, niko urusaku rwinshi. Nini nini ya nini, niko urusaku rwinshi ruzaba ninshi. Kubwibyo, kugirango umenye neza ko agaciro kokurwanya nigiciro cyagutse cyujuje ibyifuzo byunguka nibisabwa, kandi amaherezo bigasaba urusaku ruke cyangwa igipimo kinini cyerekana-urusaku, guhitamo abarwanya inyungu bigomba gusuzumwa neza no gusuzumwa hashingiwe kubisabwa byumushinga kugirango ugere ku kigereranyo cyiza cyerekana urusaku rwa sisitemu.

Incamake

Tekinoroji yo kunoza urusaku igira uruhare runini mukuzamura imikorere ya fotodetekeri nibikoresho bya elegitoroniki. Ibisobanuro bihanitse bisobanura urusaku ruke. Nkuko ikoranabuhanga risaba ibisobanuro bihanitse, ibisabwa ku rusaku, igipimo cyerekana-urusaku, hamwe n’ingufu zingana n’amajwi ya fotodetekeri nabyo biragenda byiyongera.