Page 54 - FUNDAMENTALS OF COMPUTER
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                    54                         Fundamentals of Computers                           NPP


                      The position of head,  paper and ribbon     hoS>, nona VWm [a~Z H$s pñW{V H$mo {ZåZmZwgma
                  can be drawn as:                            Xem©`m Om gH$Vm h¡:


                                                             Paper




                                                            Ribbon





                                                               Head
                                         Head cable


                      The printing speed of dot matrix  printer   S>m°Q> _o{Q´>Šg qàQ>a H$s {à¨qQ>J J{V 30 go 600
                  lies from 30 to 600 (cps).                  Ho$aoŠQ>a à{V goH§$S> (cps) hmoVr h¡Ÿ&
                  Advantages of Dot Matrix Printers:          S>m°Q> _o{Q´>Šg qàQ>g© Ho$ bm^
                  1.  Different scripts can be printed using these  1. {d{^ÝZ {b{n`m| _| H$m_ H$a gH$Vo h¢Ÿ& O¡go, A§J«oOr,
                      printers e.g. English, Devnagri, Tamil etc.  XodZmJar, V{_b Am{XŸ&
                  2.  These are cheaper.                      2. `o gñVo hmoVo h¢Ÿ&
                  3.  Low operational cost. That means printing  3. BZH$s àma§{^H$ H$s_V H$_ hmoVr h¡ Ÿ& AWm©V² à{V
                      cost per page is low.                       noO {à¨Q> bmJV ^r H$_ hmoVr h¢Ÿ&
                  Disadvantages of Dot Matrix Printers:       S>m°Q> _o{Q´>Šg qàQ>g© H$s hm{Z`m±
                  1.  Poor quality printing.                  1. AÀN>r JwUdÎmm Zht XoVo h¢Ÿ&
                  2.  Produce noise.                          2. emoa H$aVo h¢Ÿ&
                  3.  Cannot be used continuously for long time.  3. b§~o g_` VH$ bJmVma H$m`© Zht H$a gH$Vo h¢&  `o
                      They are "light duty" printers.             ""bmB©Q> S²>`yQ>r'' hmoVo h¢&
                  4.  Low printing speed.                     4. BZH$s  J{V ^r H$_ hmoVr h¡&

                   1.24 Inkjet Printers (Letter Quality Printer)  1.24 B§H$OoQ> {à¨Q>a (boQ>a Šdm{bQ>r {à¨Q>a)
                      This printer consists of a head containing  Bg àH$ma Ho$ {à¨Q>a _| hoS> Ho$ A§Xa ~hþV gmao N>moQ>o-
                  large number of small holes called nozzles. Each  N>moQ>o {N>Ð hmoVo h¢ Omo ZmoOb H$hbmVo h¡Ÿ& àË`oH$ {N>Ð Ho$
                  hole is associated with a  resistor  and an ink  nmg EH$ à{VamoY hmoVm h¡ Ÿ& O¡go hr Bg à{VamoY _| Ymam
                  (toner). When current is passed through the re-  àdm{hV hmoVr h¡ `h Ja_ hmo OmVm h¡ Am¡a BgHo$ nmg H$s
                  sistor it is heated up. Because of this the ink near  ñ`mhr ~mha {ZH$bH$a EH$ S>m°Q> ~Zm XoVr h¢ Ÿ& {à¨Q>a Ho$
                  the nozzle vaporises. The nozzle injects ink form-
                  ing a dot on the paper. The selection of nozzles  n[anW Ûmam {H$gr  Ho$aoŠQ>a H$mo  {à¨Q> H$aZo  Ho$ {bE
                  to  print  a particular  character is  done by  the  Amdí`H$ ZmoOëg H$m MwZmd {H$`m OmVm h¡ Ÿ& AmOH$b
                  printer  circuit. The latest  inkjet printers  have  Omo B§H$OoQ> {à¨Q>a Am aho h¢ CZ_| AZoH$ hoS> hmoVo h¢ Ÿ&
                  multiple heads. This allows multicolour print-  àË`oH$ hoS> _| EH$ H$ba hmoVm h¡ Ÿ& Bggo AZoH$ H$ba
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