Otu esi ebelata mkpọtụ nke ndị na-achọpụta foto

Otu esi ebelata mkpọtụ nke ndị na-achọpụta foto

Mkpọtụ nke ihe nchọpụta foto gụnyere: mkpọtụ ugbu a, mkpọtụ okpomọkụ, mkpọtụ ogbugba, mkpọtụ 1/f na mkpọtụ wideband, wdg. Nkewa a bụ naanị nke siri ike. Oge a, anyị ga-ewebata njirimara mkpọtụ na nhazi zuru ezu iji nyere onye ọ bụla aka ịghọta mmetụta nke ụdị mkpọtụ dị iche iche na akara mmepụta nke ihe nchọpụta foto. Naanị site n'ịghọta isi iyi mkpọtụ ka anyị nwere ike ibelata ma melite mkpọtụ nke ihe nchọpụta foto, si otú a na-emeziwanye oke mgbaàmà-na-mkpọtụ nke sistemụ ahụ.

Mkpọtụ ogbunigwe bụ mgbanwe na-enweghị usoro nke sitere na ọdịdị dị iche nke ndị na-ebu chaja. Karịsịa na mmetụta fotoelectric, mgbe photons kụrụ ihe ndị na-emetụta foto iji mepụta elektrọn, mmepụta nke elektrọn ndị a na-adịghị agbanwe agbanwe ma kwekọọ na nkesa Poisson. Njirimara spectral nke mkpọtụ ogbunigwe dị larịị ma na-adabereghị na oke ugboro ugboro, ya mere a na-akpọkwa ya mkpọtụ ọcha. Nkọwa mgbakọ na mwepụ: Enwere ike ịkọwa uru mgbọrọgwụ nke square (RMS) nke mkpọtụ ogbunigwe dị ka:

N'etiti ha:

e: Chaja eletrọniki (ihe dị ka 1.6 × 10-19 coulombs)

Idark: Ọkụ gbara ọchịchịrị

Δf: Bandwit

Mkpọtụ ogbunigwe ahụ kwekọrọ na oke nke ugbu a ma kwụsie ike na ugboro ole niile. N'ime usoro ahụ, Idark na-anọchite anya oke ọchịchịrị nke photodiode. Nke ahụ bụ, na enweghị ìhè, photodiode nwere mkpọtụ oke ọchịchịrị a na-achọghị. Dịka mkpọtụ dị n'ime ya na njedebe ihu nke photodetector, otú ahụ ka oke ọkụ ojii ahụ si buru ibu, otú ahụ ka mkpọtụ nke photodetector si ka ukwuu. Oke ọchịchịrị na-emetụtakwa voltaji ọrụ nke photodiode, ya bụ, ka voltaji ọrụ nke bias na-ebu ibu, otú ahụ ka oke ọkụ ojii ahụ si ka ukwuu. Agbanyeghị, voltaji ọrụ bias na-emetụtakwa ike njikọ nke photodetector, si otú a na-emetụta ọsọ na bandwit nke photodetector. Ọzọkwa, ka voltaji bias na-ebu ibu, otú ahụ ka ọsọ na bandwit na-ebu ibu. Ya mere, n'ihe gbasara mkpọtụ ogbunigwe, oke ọchịchịrị na arụmọrụ bandwit nke photodiodes, a ga-eme imewe ezi uche dị na ya dịka ihe achọrọ n'ezie si dị.

2. 1/f Mkpọtụ Flicker

Mkpọtụ 1/f, nke a makwaara dị ka mkpọtụ flicker, na-emekarị na oke ugboro ole dị ala ma jikọtara ya na ihe ndị dị ka ntụpọ ihe ma ọ bụ ịdị ọcha elu. Site na eserese njirimara spectral ya, enwere ike ịhụ na njupụta spectral ike ya dị obere nke ukwuu na oke ugboro ole dị elu karịa na oke ugboro ole dị ala, na maka mmụba ugboro 100 ọ bụla na ugboro ole, mkpọtụ njupụta spectral na-ebelata site na ugboro iri. Njupụta spectral ike nke 1/f mkpọtụ bụ nke a na-agbanwe agbanwe na ugboro ole, nke bụ:

N'etiti ha:

SI(f): Ike mkpọtụ njupụta spectral

M: Ugbu a

f: Ugboro ole

Mkpọtụ 1/f dị mkpa n'ókè obere ugboro ma na-ebelata ka ugboro ugboro na-abawanye. Njirimara a na-eme ka ọ bụrụ isi iyi nke nnyonye anya na ngwa obere ugboro. Mkpọtụ 1/f na mkpọtụ wideband na-esitekarị na mkpọtụ voltaji nke amplifier ọrụ dị n'ime photodetector. E nwere ọtụtụ isi iyi mkpọtụ ndị ọzọ na-emetụta mkpọtụ nke photodetectors, dị ka mkpọtụ ike nke amplifiers ọrụ, mkpọtụ ugbu a, na mkpọtụ okpomọkụ nke netwọk iguzogide na uru nke sekit amplifier ọrụ.

3. Ụda voltaji na mkpọtụ ọkụ eletrik nke amplifier ọrụ: E gosiri voltaji na njupụta ọkụ eletrik na ọkụ eletrik na eserese a:

Na sekit amplifier arụ ọrụ, a na-ekewa mkpọtụ ugbu a n'ime mkpọtụ ugbu a na-agbanwe ma na-agbanwe mkpọtụ ugbu a. Mkpọtụ ugbu a nke i+ na-agafe na nguzogide ime isi iyi Rs, na-emepụta mkpọtụ voltaji nhata u1= i+*Rs. I- Mkpọtụ ugbu a na-agbanwe site na nguzogide nhata gain R iji mepụta mkpọtụ voltaji nhata u2= I-* R. Ya mere, mgbe RS nke ọkọnọ ike buru ibu, mkpọtụ voltaji nke a gbanwere site na mkpọtụ ugbu a dịkwa oke ibu. Ya mere, iji mee ka mkpọtụ ka mma, mkpọtụ ọkọnọ ike (gụnyere nguzogide ime) bụkwa isi ihe dị mkpa maka njikarịcha. Njupụta spectral nke mkpọtụ ugbu a anaghị agbanwe agbanwe na mgbanwe ugboro ugboro. Ya mere, mgbe sekit ahụ mụbara ya, ọ, dị ka ọkụ gbara ọchịchịrị nke photodiode, na-emepụta mkpọtụ ogbugba nke fotodetector nke ọma.

4. Enwere ike ịgbakọ mkpọtụ okpomọkụ nke netwọk iguzogide maka uru (ihe mgbakwunye) nke sekit amplifier arụmọrụ site na iji usoro a:

N'etiti ha:

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

T: Okpomọkụ zuru oke (K)

R: Mkpọtụ okpomọkụ nke iguzogide (ohms) metụtara okpomọkụ na uru iguzogide, spectrum ya dịkwa larịị. A pụrụ ịhụ ya site na usoro ahụ na uru iguzogide mmeri ka ukwuu, otú ahụ ka mkpọtụ okpomọkụ ka ukwuu. Ka bandwidth ahụ buru ibu, otú ahụ ka mkpọtụ okpomọkụ ga-adịkwa. Ya mere, iji hụ na uru iguzogide na uru bandwidth na-emezu ihe achọrọ maka uru na ihe achọrọ maka bandwidth, ma mechaa chọọ obere mkpọtụ ma ọ bụ oke mgbaàmà-na-mkpọtụ dị elu, nhọrọ nke resistors ga-atụle nke ọma dabere na ihe achọrọ n'ezie maka ọrụ iji nweta oke mgbaàmà-na-mkpọtụ zuru oke nke sistemụ ahụ.

Nchịkọta

Teknụzụ mmezi mkpọtụ na-arụ ọrụ dị mkpa n'ịkwalite arụmọrụ nke ihe nchọpụta foto na ngwaọrụ eletrọnịkị. Ezigbo nkenke pụtara obere mkpọtụ. Ka teknụzụ na-achọ nkenke ka mma, ihe achọrọ maka mkpọtụ, oke mgbaàmà-na-mkpọtụ, na ike mkpọtụ nhata nke ihe nchọpụta foto na-abawanye elu.