Page 50 - FUNDAMENTALS OF COMPUTER
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                     50                          Fundamentals of Computers                          NPP

                    Optical mark Reader                         Am°ßQ>rH$b _mH©$ arS>a

                        This type of scanner recognises spots made  Bg àH$ma H$m ñHo$Za, n|{gb `m ñ`mhr go ~ZmE Jhao
                    with  the  help of  dark pencil  or ink.  Light is  ñnm°Q> H$mo nhMmZZo _| gj_ hmoVm h¡ Ÿ& àH$me H$mo noO na
                    made incident on a document containing a pat-
                    tern of dots. There will be difference in the  Amn{VV {H$`m OmVm h¡ Ÿ& S>mH©$ d g\o$X àH$me go àmá
                    intensity of reflected light. This intensity is con-  namd{V©V àH$me H$s Vrd«Vm _| AË`{YH$ A§Va hmoVm h¡ Ÿ&
                    verted into electrical pulses, which are sent to  Bg OmZH$mar H$mo {~Q> _on Ho$ ê$n _| _o_moar _| S>mb {X`m
                    the computer. These scanners are used to pro-  OmVm h¡ Ÿ& Bg àH$ma Ho$ ñHo$Za CZ ñWmZm| na Cn`wŠV
                    cess those documents in which one alternative  hmoVo h¢ Ohm± na AZoH$ {dH$ënm| _| go {H$gr EH$ H$m MwZmd
                    is choosen from so many choices. For example:
                                                                H$aZm hmoVm h¡Ÿ& O¡go-
                    1.  Objective-type answer  papers.  e.g.  PET,  1.  PET, PMT Am{X à{V`moJr narjmAm| H$s CÎma-erQ>
                        PMT examinations.
                                                                    H$mo Om±MZ| _| &
                    2.  Market survey, social survey etc. in which  2. _mH}$Q> gd}, gm_m{OH$ gd}, MwZmd nyd© gd} Am{X _|&
                        response of  people is to be  known. This   `hm± na ZmJ[aH$m| Ûmam AZoH$m| _| go EH$ {dH$ën na
                        can be pre-election poll. e.g. Exit-poll.
                                                                    {ZemZ bJm`m OmVm h¡Ÿ&
                    3.  Purchase order forms. The items to be pur-  3. H«$`-Am°S>©a-\$m_©, {Og_| Mmho JE gm_mZ na {ZemZ
                        chased will be marked.                      bJm`m Om gH$Vm h¡Ÿ&
                    4.  Arrival and Departure time sheets of fac-  4. \o$ŠQ´>r Ho$ H$_©Mm[a`m| Ho$ AmZo-OmZo H$s g_`-erQ>
                        tory employee.                              _| &
                    Optical Bar-code Reader                     Am°ßQ>rH$b ~ma-H$moS> arS>a
                        Bar-codes are small bars of varying thick-  AbJ Mm¡‹S>mB© Ho$ ~ma {d{^ÝZ Xy[a`m| na ~ZmH$a ~ma-
                    ness and spacing. The pattern of bars is unique  H$moS> ~Zm`m Om gH$Vm h¡ & {H$gr CËnmX Ho$ {bE `h
                    and standardised for a product. It gives infor-  A{ÛVr` d pñWa hmoVm h¡Ÿ& `h {Z_m©Vm d CËnmX Am{X H$s
                    mation of supplier, individual product. For ex-
                    ample, packages, some  books  etc. have bar  OmZH$mar XoVm h¡& O¡go, gm_mZm| Ho$ {S>ã~m| na, {H$Vm~m| na
                    codes printed  on them. Such a bar-code is a  ~ma-H$moS> ~ZmE Om gH$Vo h¢ Ÿ& Eogm hr EH$ ~ma-H$moS>
                    UPC (Universal Product Code) which uses ten  UPC (Universal Product Code) h¡ {Og_| àË`oH$
                    digits for coding an item.                  gm_mZ hoVw Xg A§H$m| H$mo H$moS> hmoVm h¡ &

















                                              Fig. 1.11: UPC (Universal Product Code)
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