Raster Scan vs Random Scan
Raster scan thiab random scan yog ob hom kev teeb tsa uas siv CRT saib. Cov no yog siv los ua qhov project lossis nthuav tawm cov ntaub ntawv softcopy nyob rau hauv daim ntawv ntawm alphanumeric lossis graphic symbology. Cov ntaub ntawv uas tso tawm kom pom siv ob txoj kev no tsis tas mus li uas yog vim li cas nws thiaj li hu ua softcopy information. Tag nrho cov ntaub ntawv uas tau nthuav tawm hauv daim duab duab tuaj yeem pom tsuas yog tias nws nyob ntawm qhov screen uas yog CRT saib.
Raster scan yog ua raws li cov thev naus laus zis hauv TV uas siv lub teeb hluav taws xob uas tau cheb hla lub vijtsam thiab nws tsim cov qauv ntawm cov teeb pom kev zoo. Nyob rau hauv cov ntaub ntawv ntawm random scan lub electron beam yog qhia rau tsuas yog cov qhov chaw ntawm lub screen qhov twg daim duab yuav tsum tau kos. Hauv random scan, ib kab ntawm daim duab yog kos ib lub sijhawm uas yog vim li cas nws tseem hu ua vector zaub. Cov zaub hauv random scan yog lub hauv paus ntawm lub computer tswj oscilloscope.
Rau tus neeg ua haujlwm, raster scan thiab random scan tuaj yeem piav qhia hauv txoj hauv kev yooj yim ntawm kev siv cwj mem los kos ib yam dab tsi ntawm lub vijtsam. Thawj txoj hauv kev yuav yog nqa thiab txo tus cwj mem thiab kos txhua yam ntawm qhov screen. Nov yog txheej txheem tedious thiab zoo li qub tam sim no.
Lwm txoj hauv kev yog kos ntau cov kab sib txuas thoob plaws lub vijtsam thiab siv lub zog siv tuaj yeem sib txawv los nthuav tawm cov duab sib txawv thiab yog li ua tiav cov duab sawv cev uas koj xav tau ntawm CRT saib. Qhov no ua rau nws yooj yim los kos kab kab rov tav thiab ntsug tib lub sijhawm thiab hu ua raster scan.
Txawm li cas los xij, tsis muaj ob hom kev siv niaj hnub no raws li txoj hauv kev tshiab ntawm tus kheej pixels tau tsim los siv los qhib thiab tawm ntawm nws tus kheej kom tawm thiab nqus lub teeb.
Qhov txawv ntawm raster thiab random scan
• Raster scan system muaj kev daws teeb meem tsawg dua thaum cov zaub random muaj kev daws teeb meem siab dua
• Thaum cov kab tsim nyob rau hauv raster scan yog zigzag, lawv yog du nyob rau hauv random scan raws li electron beam ncaj qha raws txoj kab
• Thaum nws nyuaj rau kev ua tiav qhov tseeb hauv random scan, qib siab ntawm qhov tseeb tau ua tiav hauv raster scan nrog kev pab ntawm cov shading siab heev thiab cov txheej txheem zais saum npoo
• Thaum random scan yog costlier, txo tus nqi nco hauv raster scan tau ua rau nws nrov
• Electron beam yog swept thoob plaws qhov screen, ib kab ntawm ib lub sij hawm los ntawm sab saum toj mus rau hauv qab nyob rau hauv cov ntaub ntawv ntawm raster scan nyob rau hauv cov ntaub ntawv ntawm raster scan, thaum nyob rau hauv cov ntaub ntawv ntawm random scan electron beam ncaj qha mus rau cov seem ntawm lub npo qhov twg daim duab yuav tsum tau kos
• Random scan kos cov kab txuas ntawm tus nqi ntawm 30-60 zaug hauv ib thib ob, thaum rov ua dua tshiab ntawm raster scan yog nqa tawm ntawm tus nqi ntawm 60-80 ntas ib pliag.
