Facsimile - los ntawm lub invention rau tam sim no hnub

Facsimile (nyob rau hauv lwm yam lus - telephoto) - ib tug ntev-deb kis tau tus mob ntawm ib tug tseem duab (ntawv nyeem, illustrations, duab) tom playback ntawm tus tau txais yam khoom ntawd. Keeb kwm tau ua los ntawm txoj kev loj hlob ntawm telegraphy, tab sis yog tau kis ntau tshaj ib hom ntawm cov ntaub ntawv thiab yog resistant rau cuam.

Faxing yog siv los hloov kev yees duab telegrams, nrog decentralized sau periodicals (hloov lwm lub tsev ntaub ntawv ntawm ntawv xov xwm nplooj ntawv thiab illustrations), loj Enterprises rau cov kev pauv ntawm ntau lawm cov lus qhia, kom tau txais cov ntaub ntawv los ntawm satellites thiab huab cua noj (pauv gidrometeokartami), raws li zoo raws li nyob rau hauv ntau lwm tus neeg mob.

Lub hloov lwm lub txheej txheem yog nqa tawm siv ib tug facsimile siv lub tshuab (fax). Cov kev khiav hauj lwm hauv paus ntsiab lus ntawm ib tug fax yog raws li nram no: ib tug transmitter tsev ua lub koog tsev ntawm lub kis duab (ntawv nyeem, duab) rau hauv ntau qhov chaw me me (tus thiaj li hu ua elementary chaw ..), uas txawv los ntawm txhua lwm yam nyob rau hauv ib tug tej yam kos npe rau, feem ntau yog los ntawm kho qhov muag ceev). Ces tag nrho cov ntsiab successively hloov dua siab tshiab los ntawm cov duab dluab rau hauv hluav taws xob pulses txaus. Ntaub ntawv hais txog cov kev hloov khoom yog khaws cia rau hauv lub xaiv kev.

Ces tus fax raws li ib tug series ntawm hluav taws xob Pib ntsais koj teeb kis tau los ntawm cov kev sib txuas lus txoj kab, uas ua raws li ib tug dog dig hauv xov tooj txoj kab. Thaum lub receiver, lub rov qab transformation yuav siv sij hawm qhov chaw thaum tswj ib theem ntawm cov ntsiab, nrog cov uas peb tau ib daim qauv ntawm cov kev kawm cov duab rau peb.

fax hauv paus ntsiab lus yog tsim los pab nyob rau hauv 1855 los ntawm cov Italian physicist J. Caselli. apparatus tsim lawv mus rau cov hloov duab thov kom muaj ib cov hlau lead ntawv ci nrog ib tug tshwj xeeb cov kua roj vanish nrog heev tsawg hluav taws xob conductivity (yuav luag pes tsawg). Yog li, ib tug duab muaj li ntawm cov ntsiab ntawm cov alternating siab (ci) thiab tsawg conductivity. Cov hu pin, zawv zawg duab ci ib kis tam sim no pulses thiab tam sim no-free Pib ntsais koj teeb. Txais duab electrochemical txoj kev sau tseg rau tus ntawv ci.

Cov prototypes ntawm cov niaj hnub fax siv mus rau kis lus rau lub hlua taws xob cov kab Paris - Marseille thiab Moscow - St. Petersburg, tab sis maj mam tuaj mus naught vim hais tias ntawm nws cov zoo tag nrho thiab cov complexity ntawm cov kis txheej txheem.

Nyob rau hauv 1868, B. Meier yog invented ib txoj kev uas tau txais dluab thiab cov ntaubntawv povthawj siv nws rau lub tiaj ntawv nrog ib yam muab kauv, them nrog xim. Spiral, clinging rau tus ntawv thaum lub sij hawm, sab laug ib tug xov tooj ntawm tus cwj nrag, uas muaj ib tug duab. Qhov no txoj kev, zoo tag nrho thiab siv niaj hnub no.

Nyob rau hauv lub thib nees nkaum xyoo pua facsimile mus txog ib tug qualitatively theem tshiab ua tsaug rau cov emergence ntawm ib tug dav network ntawm kev sib txuas lus kab, cov invention ntawm lub tshuab nqus tsev leeg, cov discovery ntawm lub photoelectric nyhuv. Nyob rau hauv lub 30s thawj luam cov cav tov nyob rau hauv peb lub teb chaws. Nyob rau hauv lub neej yav tom ntej, txoj kev siv cov photographic cov ntaub ntawv thiab txoj kev twb tau muab siv nyob ib ncig ntawm lub ntiaj teb no.

Niaj hnub nimno facsimile kev sib txuas lus yog nqa tawm los ntawm txhais tau tias ntawm ib tug transmitter, receiver thiab kev sib txuas lus kab. Thaum lub transmitter, taw tes teeb chaw kab sau nyob ib ncig tag nrho saum npoo ntawm cov thawj, faib nws mus rau hauv elementary feem (pawm no ntau npau) ntawm txawv lub teeb reflectivity. Reflected los ntawm lawv, lub teeb flux ntawm nce mus nce los siv ntog rau hauv photoelectric converter thiab hloov dua siab tshiab rau hauv ib tug video teeb liab, ces modulates deeg (amplitude los yog pes tsawg zaus) txhais cov kev yees duab teeb liab mus rau hauv yooj yim rau kis tau tus mob tshaj ib qhov txuas zoo. Kev sib txuas lus kab - pa wired los yog wireless xov tooj raws. Nyob rau hauv cov ntaub ntawv ntawm kis ib tug loj npaum li cas ntawm cov ntaub ntawv (cov ntawv xov xwm cov nplooj ntawv, piv txwv li) siv ib tug multichannel kev sib txuas lus nrog broadband raws.

Thaum lub receiver, lub facsimile apparatus yog ua demodulation ntawm tus tau txais lub teeb liab (xaiv) thiab hloov lub caij nyoog kawg no nyob rau hauv cov tsab ntawv uas yog muab sau tseg rau hauv lub medium lub (m. E. Nws convolution) nyob rau hauv tib theem zuj zus raws li cov thawj. Txoj kev rau cov ntaubntawv povthawj siv tus tau txais lub teeb liab:

- Photographic (nyob rau photographic ntawv los yog zaj duab xis uas yog muab tso rau hauv ib lub teeb-ceev daig kab). Nyob rau hauv cov ntaub ntawv no, nws yog tsis yooj yim sua kom tswj tau tus zoo tshaj ntawm cov tau txais cov lus mus txog rau thaum tus txheej txheem ntawm photochemical ua xws li ib tug cab kuj.

- Electrochemical (cov duab yog muab tso rau ib tug tshwj xeeb daim ntawv uas blackens thaum ib tug tam sim no yog dhau los ntawm nws).

- number case - nyob rau hauv lub tiaj ntawv smeared nrog number case cwj mem los yog rau cov menyuam.