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                  NPP                  Computer Basics and Windows Fundamentals                    49


                  text, a picture or hand-written document. A dot  {MÌ `m hmW  go {bIr OmZH$mar hmo gH$Vr h¡ Ÿ& H$mJO na
                  on  the document represents  a '1'.  The white  Omo S>m°Q> ~ZVm h¡ Cgo 1 go VWm {~Zm S>m°Q> dmbo ñnm°Q> H$mo
                  spot represents a '0'. This representation is called
                  a bit map. Each bit is called a pixel or picture  0 go Xem©Vo h¢ Ÿ& Bg Vah Ho$ à{V{Z{YËd H$mo {~Q>-_on
                  element. There are two types of scanners which  H$hVo h¢ Ÿ& àË`oH$ {~Q> H$mo EH$ {nŠgob H$hVo h¢ Ÿ& Xmo
                  use optical character recognition:          àH$ma Ho$ ñHo$Za Bg {gÕm§V na H$m`© H$aVo h¢ Ÿ&
                       Hand-held Scanner.                         h|S>-hoëS> ñHo$Za
                       Flat bed Scanner (page scanner).           âboQ> ~oS> `m noO ñHo$Za
                      Hand-held Scanner: This can be operated     h|S>-hoëS> ñHo$Za … Bg àH$ma Ho$ ñHo$Za H$mo EH$ hmW
                  conveniently with a single hand. It contains a  go g§^mbm Om gH$Vm h¡Ÿ& Bg_| ~hþV gmar LEDs hmoVr h¢Ÿ&
                  set of LEDs. It is placed over the surface to be  `h Cg gVh Ho$ gm_Zo aIm OmVm h¡, {OgH$s OmZH$mar
                  scanned. Then slowly moved from top to bot-  n‹T>Zm h¡Ÿ& CgHo$ níMmV² Bgo Yrao-Yrao D$na go ZrMo bm`m
                  tom. The emitted light falls on various dots on
                  the surface. The intensity of light differs from  OmVm h¡Ÿ& LED go {ZH$bZo dmbm àH$me H$mJO Ho$ {d{^ÝZ
                  the dark  and white spot. This  information  is  q~XwAm| na n‹S>Vm h¡ Ÿ& BgHo$ níMmV² `hr àH$me namd{V©V
                  stored as a bitmap. The scanner must be moved  hmoH$a \$moQ>mo{S>Q>oŠQ>a na n‹S>Vm h¡Ÿ& KZo d g\o$X q~XwAm| go
                  steadily and  carefully to  avoid getting incor-  dmng AmZo dmbr àH$me-Vrd«Vm {^ÝZ hmoVr h¢Ÿ& BÝh| {~Q>_on
                  rect bitmap. These scanners are used for pre-  Ho$ ê$n _| H$åß`yQ>a H$s _o_moar _| S>mb {X`m OmVm h¡Ÿ&
                  paring computer oriented bills.             BZH$m Cn`moJ H$åß`yQ>a go {~b ~ZmZo _| {H$`m OmVm h¡Ÿ&
                      Flat bed scanner (page scanner): It con-    âboQ> ~oS> `m noO ñHo$Za … `h ~‹S>o AmH$ma H$m ~m°Šg
                  sists of a box with a glass plate. The complete  hmoVm h¡ Ÿ& Bg_| EH$ ~‹S>r H$m±M H$s ßboQ> hmoVr h¡, {OgHo$
                  document can be put onto the glass plate. The  D$na  nyao H$mJO H$mo aIm Om gH$Vm h¡ Ÿ& H$m±M H$s ßboQ>
                  light source  is placed below the  glass  plate.
                  Light beam scans the complete document. The  Ho$ ZrMo àH$me H$m òmoV hmoVm h¡ Ÿ& Bggo àmá àH$me Ûmam
                  contents of the page are stored as a bitmap in  g§nyU© gVh H$s ñHo$qZJ H$r OmVr h¡Ÿ& noO H$s OmZH$mar
                  the memory. This scanner can also store colour  H$mo {~Q>_on _| ~XbH$a _o_moar _| S>mb {X`m OmVm h¡ Ÿ&
                  images. The stored image can be reprinted by a  AmYw{ZH$ ñHo$Za {d{^ÝZ a§Jm| H$s OmZH$mar ^r n‹T> boVo h¢Ÿ&
                  printer.                                    Amdí`H$Vm n‹S>Zo na Bg OmZH$mar H$mo {à¨Q>a H$s ghm`Vm
                                                              go àmá {H$`m Om gH$Vm h¡ Ÿ&
















                                                      Fig. 1.10: Scanner
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