Uburyo bwo kugabanya urusaku rw'ibikoresho bipima foto

Uburyo bwo kugabanya urusaku rw'ibikoresho bipima foto

Urusaku rw'ibikoresho bipima urumuri rurimo ahanini: urusaku rw'amashanyarazi, urusaku rw'ubushyuhe, urusaku rw'amasasu, urusaku rwa 1/f n'urusaku rw'umurambararo munini, nibindi. Iri shyirahamwe ni urusaku rusanzwe. Kuri iyi nshuro, tuzagaragaza imiterere y'urusaku irambuye n'uburyo bwo gushyira mu byiciro kugira ngo dufashe buri wese gusobanukirwa neza ingaruka z'ubwoko butandukanye bw'urusaku ku bimenyetso bisohoka by'ibikoresho bipima urumuri. Ni mu gusobanukirwa inkomoko y'urusaku gusa dushobora kugabanya no kunoza urusaku rw'ibikoresho bipima urumuri, bityo tukanoza ikigereranyo cy'urusaku hagati y'ibimenyetso n'urusaku muri sisitemu.

Urusaku rw'amasasu ni ihindagurika ritunguranye riterwa n'imiterere itandukanye y'ibikoresho bitwara umuriro. Cyane cyane mu ngaruka z'amashanyarazi, iyo fotoni zikubita ibice bifata urumuri kugira ngo bikore electron, ikorwa ry'izi electron riba ritunguranye kandi rijyanye n'ikwirakwizwa rya Poisson. Imiterere y'urusaku rw'amasasu ni ndende kandi ntirishingiye ku bunini bw'inshuro, bityo byitwa urusaku rw'umweru. Ibisobanuro by'imibare: Agaciro k'urusaku rw'amasasu mu mizi (RMS) gashobora kugaragazwa nka:

Muri bo:

e: Gukoresha amashanyarazi hakoreshejwe ikoranabuhanga (hafi 1.6 × 10-19 coulombs)

Idark: Umugezi wijimye

Δf: Ubugari bw'umuyoboro

Urusaku rw'amasasu rungana n'ubunini bw'umuyoboro w'amashanyarazi kandi ruhoraho kuri frequencies zose. Muri formula, Idark ihagarariye umuyoboro wijimye wa photodiode. Ni ukuvuga ko, iyo urumuri rudafite, photodiode ifite urusaku rwijimye rudakenewe. Kubera ko urusaku ruri ku mpera y'imbere y'icyuma gipima urumuri, uko umuyoboro wijimye uba munini, ni ko urusaku rw'icyuma gipima urumuri rurushaho kuba rwinshi. Umuyoboro wijimye nawo ugirwaho ingaruka na voltage ikora ya photodiode, ni ukuvuga ko voltage ikora ya bias ari nini, ni ko umuyoboro wijimye uba munini. Ariko, voltage ikora ya bias igira ingaruka ku bushobozi bw'icyuma gipima urumuri, bityo bigira ingaruka ku muvuduko n'umuvuduko w'icyuma gipima urumuri. Byongeye kandi, uko voltage ikora ya bias ni ko umuvuduko n'umuvuduko birushaho kuba byinshi. Kubwibyo, ku bijyanye n'urusaku rw'amasasu, umuyoboro wijimye n'imikorere ya bandwidth ya photodiode, igishushanyo gikwiye gikwiye gukorwa hakurikijwe ibisabwa by'umushinga.

2. Urusaku rw'urusaku rw'urusaku rwa 1/f

Urusaku rwa 1/f, ruzwi kandi ku izina rya flicker noise, rukunze kubaho mu rugero rwo hasi kandi rufitanye isano n'ibintu nko kugira inenge mu bikoresho cyangwa isuku y'ubuso. Dukurikije igishushanyo cyayo cyerekana imiterere ya spectral, bigaragara ko ubucucike bwa spectral yayo ari buto cyane mu rugero rwo hejuru ugereranyije n'urugero rwo hasi, kandi ku nshuro 100 ziyongereyeho frequency, urusaku rw'ubucucike bwa spectral rugabanuka inshuro 10. Ubucucike bwa spectral y'urusaku rwa 1/f bungana n'ubucucike, ni ukuvuga:

Muri bo:

SI(f) : Ubucucike bwa spectral y'imbaraga z'urusaku

I: Ubu

f: Inshuro

Urusaku rwa 1/f ni ingenzi mu rugero rw'umuvuduko muto kandi rugabanuka uko umuvuduko wiyongera. Iyi miterere ituma iba isoko ikomeye y'ingaruka mbi mu mikoreshereze y'umuvuduko muto. Urusaku rwa 1/f n'urusaku rw'umuvuduko munini ahanini bituruka ku rusaku rw'amashanyarazi rwa amplifier ikora imbere muri fotodetector. Hari izindi nkomoko nyinshi z'urusaku zigira ingaruka ku rusaku rw'amplifier ikora, nko urusaku rw'amashanyarazi rwa amplifier ikora, urusaku rw'amashanyarazi, n'urusaku rw'ubushyuhe bw'umuyoboro w'ubudahangarwa mu kwiyongera kw'imiyoboro ikora amplifier.

3. Urusaku rw'amashanyarazi n'umuvuduko w'amashanyarazi by'imashini ikora: Ubucucike bw'amashanyarazi n'umuvuduko w'amashanyarazi bigaragara ku ishusho ikurikira:

Mu miyoboro y’amashanyarazi ikora, urusaku rw’amashanyarazi rugabanyijemo urusaku rw’amashanyarazi mu cyiciro cya kabiri n’urusaku rw’amashanyarazi ahinduranya. Urusaku rw’amashanyarazi mu cyiciro cya kabiri i+ runyura mu gice cya mbere cya Rs, rutanga urusaku rw’amashanyarazi angana na u1= i+*Rs. I- Urusaku rw’amashanyarazi ahinduranya runyura mu gice cya R kugira ngo rutange urusaku rw’amashanyarazi angana na u2= I-* R. Rero iyo RS y’amashanyarazi ari nini, urusaku rw’amashanyarazi ruhinduka mu rusaku rw’amashanyarazi narwo ni runini cyane. Kubwibyo, kugira ngo rurusheho kunoza urusaku, urusaku rw’amashanyarazi (harimo no kwirinda imbere) narwo ni icyerekezo cy’ingenzi cyo kunoza urusaku. Ubucucike bw’urusaku rw’amashanyarazi ntibuhinduka bitewe n’impinduka z’impinduka. Kubwibyo, nyuma yo kongererwa imbaraga n’uruziga, rwo, kimwe n’umugezi wijimye wa photodiode, rukora urusaku rw’amasasu rwa photodetector.

4. Urusaku rw'ubushyuhe bw'umuyoboro w'ubudahangarwa ku kwiyongera (amplification factor) y'urusobe rw'amajwi rushobora kubarwa hakoreshejwe formula ikurikira:

Muri bo:

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

T: Ubushyuhe busesuye (K)

R: Urusaku rw'ubushyuhe (ohms) rufitanye isano n'ubushyuhe n'agaciro k'ubudahangarwa, kandi spectrum yarwo ni ndende. Bigaragara muri formula ko uko agaciro k'ubudahangarwa bw'ubushyuhe kangana, ni ko urusaku rw'ubushyuhe rungana. Uko bandwidth ingana, ni ko urusaku rw'ubushyuhe ruzaba rwinshi. Kubwibyo, kugira ngo agaciro k'ubudahangarwa n'agaciro k'ubudahangarwa byujuje ibisabwa ku bukungu n'ibisabwa ku bukungu, kandi amaherezo bisaba urusaku ruto cyangwa igipimo kinini cy'ikimenyetso hagati y'urusaku n'urusaku, guhitamo ibirwanya inyungu bigomba gusuzumwa neza no gusuzumwa hashingiwe ku bisabwa by'umushinga nyawo kugira ngo hagerwe ku gipimo cyiza cy'ikimenyetso hagati y'urusaku n'urusaku muri sisitemu.

Incamake

Ikoranabuhanga ryo kunoza urusaku rigira uruhare runini mu kunoza imikorere y’ibikoresho bipima amashusho n’ibikoresho by’ikoranabuhanga. Ubuhanga buhanitse bivuze urusaku ruto. Kubera ko ikoranabuhanga risaba ubuziranenge buhanitse, ibisabwa kugira ngo urusaku rube rwinshi, igipimo cy’urusaku hagati y’ibimenyetso n’urusaku, hamwe n’imbaraga zingana z’ibikoresho bipima amashusho nabyo birimo kwiyongera cyane.