Page 56 - FUNDAMENTALS OF COMPUTER

56 Fundamentals of Computers NPP

contailing electrostatically charged particles. Amamo{nV H$a {X`m OmVm h¡ Ÿ& A~ O¡go hr S´>_ Q>moZa
The toner is attracted by charge area of the (ñ`mhr nmdS>a) Ho$ g§nH©$ _| AmVm h¡ V~ Q>moZa Ho$ pñWa
drum. Now the ink from the the drum moves d¡Úw{VH$ ê$n go Amdo{eV H$U S´>_ Ho$ Amdo{eV joÌ H$mo
to the paper. This paper is passed through {MnH$ OmVo h¡& A~ `o hr H$U Imbr H$mJO na Mbo OmVo
heated rollers to bind the ink. Scraper is used h¢ bo{H$Z BZH$mo AÀN>r Vah H$mJO na O_mZo Ho$ {bE
to remove the residual toner from the drum. Ja_ amobam| _| go ^oOm OmVm h¡& EH$ ñH«o$na hmoVm h¡ Omo
~Mr hþB© Q>moZa H$mo gm\$ H$aVm h¡ Ÿ&
Advantages of Laser Printer boOa qàQ>a Ho$ bm^

1. Quality of printing is very good. 1. ~hþV hr AÀN>r JwUdÎmm H$s {à¨qQ>JŸ&
2. Low noise. 2. H$_ emoaŸ&
3. High speed printing. 3. CÀM J{V go {à¨qQ>JŸ&

Disadvantages of Laser Printer boOa qàQ>a H$s hm{Z`m±
1. High cost. 1. CÀM àma§{^H$ bmJVŸ&
1.26 Drum Printer NPP 1.26 S´>_ {àÝQ>a
This is a line printer. The most important `h EH$ bmB©Z {à¨Q>a h¡ Ÿ& BgH$m _hËdnyU© {hñgm
part of it, is a rotating drum. The characters to EH$ Ky_Vm hþAm S´>_ hmoVm h¡ Ÿ& Bg na Ho$aoŠQ>a C^ao hþE
be printed are embossed on the drum surface. hmoVo h¢Ÿ& EH$ n§pŠV Ho$ {bE EH$ g§nyU© Ho$aoŠQ>a H$m goQ>
One complete set is embossed for one line. This C^am hþAm hmoVm h¡ Ÿ& Bgo {ZåZ {MÌ go g_P gH$Vo h¢…
is clear from the following diagram:
Ribbon
Hammers Paper

A B C D E F G H I J K L M NO
Rotating B C D E F G H I J K L M NO P
drum C D E F G H I J K L M N O P Q
D E F G H I J K L M N O P Q R
E F G H I J K L M N O P Q R S
Computer supplies the characters of a line H$åß`yQ>a {àÝQ>a Ho$ ~\$a a{OñQ>a H$mo EH$ bmBZ Ho$
to the printer buffer register. This register can H¡$aoŠQ>g© XoVm h¡ a{OñQ>a 132 H¡$aoŠQ>g© ñQ>moa H$a gH$Vm
store 132 characters. Signal synchronised ham- h¡Ÿ& {g½Zb {gÝH«$moZmBÁS> h¡_g© S´>_ Ho$ D$na aIo OmVo
mers are place above the drum. When the ham- h¢Ÿ& O~ h¡_a ñQ´>mBH$ H$aVm h¡ Vmo H$mJO na H¡$aoŠQ>a {àÝQ>
mer strikes, character is printed on the paper.
The movement of drum and the strike of ham- hmoVo h¢Ÿ& S´>_ H$m _yd_oÝQ> VWm h¡_a H$m ñQ>mBH$ {àÝQ>a
mers are under control of printer circuit. One g{H©$Q> Ho$ {Z`ÝÌU _| hmoVo h¢Ÿ& EH$ bmBZ H$mo {àÝQ> H$aZo
full revolution is needed to print one line. Each Ho$ {bE EH$ nyU© MH«$ H$s Amdí`H$Vm hmoVr h¡Ÿ& àË`oH$
drum has a fixed font. S´>_ _| {ZpíMV \$moÝQ> hmoVo h¢Ÿ&