printers

WHAT ARE PRINTERS….?

• PRINTERS ARE THE MOST COMMONLY USED OUTPUT DEVICES.

• IT PROVIDE THE USER WITH A PERMANENT VISUAL RECORD OF THE OUTPUT IN HUMAN READABLE FORM

KNOWN AS HARD COPY.• THEY CAN PRINT ON PLAIN PAPER OR ON SPECIALLY

PREPARED FORMS SUCH AS INVOICES LABELS , BILLS , CHECKS AND OTHER SPECIAL PURPOSE FORMS USED

IN BUSINESS.• THERE ARE SEVERAL TYPES OF PRINTERS DESIGNED

FOR WIDE RANGE OF APPLICATION.

IMPACT PRINTERS

• IMPACT PRINTER PRODUCES TEXT AND IMAGES WHEN TINY WIRE PINS ON PRINT

HEAD STRIKE THE INK RIBBON BY PHYSICALLY CONTACTING THE PAPER.

NON IMPACT PRINTERS. NON IMPACT PRINTER PRODUCES TEXT AND

GRAPHICS ON PAPER WITHOUT ACTUALLY STRIKING THE PAPER.

TYPES OF IMPACT

IMPACT PRINTER’ S.DOT MATRIX PRINTER

. DRUM PRINTER

. CHAIN PRINTER.DAISY WHEEL PRINTER

• LINE PRINTERS: THE LINE PRINTER IS AN IMPACT PRINTER IN WHICH ONE LINE OF TEXT

IS PRINTED AT A TIME . • IT IS DIVIDED INTO TWO TYPES:

• DRUM PRINTERS• CHAIN PRINTERS

• CHARACTER PRINTERS: A CHARACTER PRINTER WILL PRINT ONE CHARACTER AT A

TIME INSTEAD OF ONE LINE AT A TIME. • IT IS DIVIDED INTO TWO TYPES:

• DAISY WHEEL• DOT MATRIX

DOT MATRIX

• DOT MATRIX REFERS TO THE WAY THE PRINTER CREATES CHARACTERS OR IMAGES ON PAPER.

• THIS IS DONE BY SEVERAL TINY PINS , ALIGNED IN A COLUMN , STRIKING AN INK RIBBON

POSITIONED BETWEEN THE PINS AND THE PAPER , CREATING DOTS ON THE PAPER.

• CHARACTERS ARE COMPOSED OF PATTERNS OF THESE DOTS BY MOVING THE PRINT HEAD

LATERALLY ACROSS THE PAGE IN VERY SMALL INCREMENTS.

DOT MATRIX PRINTER

• 9-PIN PRINTERS:THESE PRINTERS ARE SOMETIMES CALLED 9 -PIN

PRINTERS BECAUSE THEY HAVE TWO EXTRA VERTICAL DOTS FOR CREATING THE PARTS OF

LOWERCASE LETTERS G,J,P AND Y THAT GO BELOW THE NEXT LINE

• 24-PIN PRINTERS:THE 24-PIN DOT MATRIX PRINTER USES A SERIES OF

OVERLAPPING DOTS THE MORE DOTS , THE BETTER THE QUALITY OF THE LETTER PRODUCED . SOME DOT

MATRIX PRINTERS CAN PRODUCE COLOR IMAGES.

CHARACTER QUALITY :

• DRAFT QUALITY: A CHARACTER MAY BE PRODUCED AS DRAFT QUALITY , A

ROUGH QUALITY , WHEN IT IS PRINTED ONCE .• NEAR LETTER QUALITY :

IT MAY BE PRODUCED AS NEAR LETTER QUALITY(NLQ) AS CRISPER IMAGE , WHEN THE CHARACTER IS PRINTED

TWICE.THE SECOND TIME , THE PRINT HEAD IS POSITIONED

SLIGHTLY TO THE RIGHT OF THE ORIGINAL IMAGE .SOME CAN ALSO PRINT IS CONDENSED MODE , WHICH

ALLOWS MORE WORDS TO BE FITTED ON A LINE.

ADVANTAGES

• VERSATILE

• PRINT LETTERS IN ITALICS OR BOLD

• RELATIVELY INEXPENSIVE

• USED TO PRINT CARBON COPIES

DAISY WHEEL PRINTERS

• DAISY WHEEL PRINTERS USE AN IMPACT PRINTING TECHNOLOGY INVENTED IN 1969 BY DAVID S.LEE AT

DIABLO DATA SYSTEMS.• IT USES INTERCHANGEABLE PRE-FORMED TYPE

ELEMENTS, EACH WITH 96 GLYPHS, TO GENERATE HIGH-QUALITY OUTPUT COMPARABLE TO PREMIUM

TYPEWRITERS SUCH AS THE IBM GOLFBALL SELECTRIC, BUT THREE TIMES FASTER.

• DAISYAND-WHEEL PRINTING WAS USED IN ELECTRONIC TYPEWRITERS, WORD PROCESSORS AND

COMPUTER SYSTEMS FROM 1972.

WORKING

. A DAISY WHEEL PRINTER USES A DAISY WHEEL, A WHEEL WITH EACH PETAL CONTAINS AN EMBOSSED

CHARACTER.

. A MOTOR SPINS THE WHEEL AT A HIGH RATE.

• WHEN THE DESIRED CHARACTER AT THE END OF THE PETAL REACHES THE 12 O’ CLOCK POSITION, IT IS

HAMMERED ONTO A LEAKED RIBBON WHICH STRIKES THE PAPER, TRANSFERRING THE CHARACTER TO PAPER.

FEATURES

• DAISY WHEEL PRINTERS ARE SOMETIMES CALLED LETTER-QUALITY PRINTERS BECAUSE THEY

PRODUCE A PRECISE, CLEAR, HIGH-QUALITY IMAGE.• IN MANY RESPECTS THE DAISY WHEEL IS A SIMILAR

TO A STANDARD TYPEWRITER IN THE WAY IT FORMS ITS LETTERS ON THE PAGE, DIFFERING ONLY IN THE DETAILS OF THE MECHANISM(DAISY WHEEL

VS. TYPE BARS OR THE TYPE BALL USED ON IBM SELECTRIC TYPEWRITERS).

ADVANTAGES

• DIFFERENT TYPEFACES AND SIZES CAN BE USED

• POSSIBLE TO USE MULTIPLE FONTS

• BOLD TYPE FACILITY

DRUM PRINTER

• AN OLD LINE PRINTER TECHNOLOGY THAT USED FORMED CHARACTER IMAGES AROUND A

CYLINDRICAL DRUM AS ITS PRINTING MECHANISM.

• WHEN THE DESIRED CHARACTER FOR THE SELECTED POSITION ROTATED AROUND TO THE HAMMER LINE , THE HAMMER HIT THE PAPER

FROM BEHIND AND PUSHED IT INTO THE RIBBON AND ONTO THE CHARCTER.

WORKING :• FOR EACH POSSIBLE PRINT POSITION , THAT IS , OPPOSITE TO

EACH COLUMN OF THE DRUM , THERE IS A PRINT HAMMER LOCATED BEHIND THE PAPER.

• THE DRUM ROTATES AT HIGH SPEED (IT TAKES ABOUT 60 MILLISECONDS TO MAKE ONE COMPLETE REVOLUTION) AND THESE HAMMERS STRIKE THE PAPER ALONG WITH THE INKED

RIBBON , AGAINST THE PROPER CHARACTER ON THE DRUM AS IT PASSES.

• ONE REVOLUTION OF A DRUM IS REQUIRED TO PRINT EACH LINE.• THIS MEANS THAT ALL THE CHARACTERS ON THE LINE ARE NOT

PRINTED AT EXACTLY THE SAME TIME , BUT THE TIME REQUIRED TO PRINT THE ENTIRE LINE IS FAST ENOUGH TO PRINT THE ENTIRE

LINE IS FAST ENOUGH TO CALL THEM LINE PRINTERS.

• CHARACTERS:• THE NUMBER OF COLUMNS IS EQUAL TO

THE NUMBER OF PRINT POSITIONS ON A LINE.

• MOST OF THE DRUMS USE 96 , 120 , 132 AND 160 CHARACTERS PER LINE , WITH 132

CHARACTERS PER LINE BEING THE MOST POPULAR.• SPEED:

• SPEED OF DRUM PRINTERS VARY FROM 200 TO OVER 2000 LINES PER MINUTE.

•ADVANTAGES:• LESS EXPENSIVE• USE LESS INK

•DISADVANTAGES:• VERY NOISY• SLOW SPEED

• SPACE CONSUMING

CHAIN PRINTERS

• AN EARLY PRINTER THAT USED TYPE SLUGS LINKED TOGETHER IN A CHAIN AS ITS PRINTING

MECHANISM.• THE CHAIN SPINS HORIZONTALLY AROUND A SET OF

HAMMERS.• WHEN THE DESIRED CHARACTER IS IN FRONT OF THE

SELECTED PRINT COLUMN , THE CORRESPONDING HAMMER HITS THE PAPER INTO THE RIBBON AND

ONTO THE CHARACTER IN THE CHAIN .• CHAIN AND TRAIN PRINTERS GAVE WAY TO BRAND

PRINTERS IN THE EARLY 1980’S.

WORKING:

• THE CHAIN REVOLVES A HORIZONTAL AND PASSES THROUGH ALL THE PRINT POSITIONS .

• AS A CHARACTER ON CHAIN PASS THE POSITION WHERE IT IS TO PRINT, THE HAMMER PRESSES THE

PAPER AGAINST THE RIBBON TO PRODUCE A CHARACTER IMAGE.

• BECAUSE THE CHARACTER SET IS REPEATED AROUND THE CHAIN, IT IS NECESSARY TO WAIT FOR THE CHAIN TO MAKE A COMPLETE REVOLUTION TO POSITION THE

DESIRED CHARACTER IN THE CORRECT PRINTER POSITION.

SPEED

• CHAIN PRINTERS ARE GENERALLY USED WITH MAINFRAME COMPUTERS.

• IT CAN PRINT WITH WIDTHS UP TO 132 CHARACTERS (SOME MODELS ARE 144 CHARACTERS WIDE).

• RECORDS WITH MULTIPLE COPIES AND CARBONS ARE READILY PREPARED.

• THE CHAIN PRINTER HAS ENOUGH IMPACT TO LEGIBLY STRIKE THROUGH AS MANY AS 10 COPIES. • SPEED OF CHAIN PRINTERS RANGE FROM 400 TO

2400 LINES PER MINUTE(1PM).

DISADVANTAGES

CHAIN PRINTERS HAVE TWO DISADVANTAGES:

. THEY ARE RELATIVELY EXPENSIVE.

. SOME OF THEM HAVE CHAINS THAT ARE DIFFICULT TO CHANGE.

TYPES OF NON IMPACT PRINTERS

• INKJET PRINTERS

• LASER PRINTERS

• ELECTROSTATIC PRINTERS

INKJET PRINTERS

AN INKJET PRINTER IS ANY PRINTER THAT PLACES EXTREMELY SMALL DROPLETS OF INK ONTO PAPER TO CREATE AN IMAGE

, THE INK IS DEPOSITED BY THE PRINT HEAD DESCRIBED BELOW.

IF YOU EVER LOOK AT A PIECE OF PAPER THAT HAS COME OUT OF AN INKJET PRINTER , YOU KNOW THAT :

o THE DOTS ARE EXTREMELY SMALL(USUALLY BETWEEN 50 AND 60 MICRONS IN DIAMETER) , SO SMALL THAT THEY ARE

TINIER THAN THE DIAMETER OF A HUMAN HAIR (70 MICRONS)

o THE DOTS ARE POSITIONED VERY PRECISELY , WITH RESOLUTIONS OF UP TO 1440X720 DOTS PER INCH(DPI)

o THE DOTS CAN HAVE DIFFERENT COLORS COMBINED TOGETHER TO CREATE PHOTO QUALITY IMAGES.

INSIDE AN INKJET PRINTER :PARTS OF A TYPICAL INKJET PRINTER INCLUDE :• PRINT HEAD ASSEMBLY

PRINT HEAD INK CARTRIDGES

PRINT HEAD STEPPERBELT

STABILIZER BAR• PAPER FEED ASSEMBLY

PAPER TRAY/FEEDERROLLERS

PAPER FEED STEPPER MOTOR• POWER SUPPLY • CONTROL CIRCUITRY• INTERFACE PORT

PRINT HEAD ASSEMBLY• PRINT HEAD- THE CORE OF AN INKJET PRINTER , THE PRINT HEAD

CONTAINS A SERIES OF NOZZLES THAT ARE USED TO SPRAY DROPS OF INK.• INK CARTIGES- DEPENDING ON THE MANUFACTURE AND MODEL OF THE

PRINTER , INK CARTRIDGES COME IN VARIOUS COMBINATIONS , SUCH AS SEPARATE BLACK AND COLOR CARTRIDGES , COLOR AND BLACK IN A

SINGLE CARTRIDGE FOR EACH INK COLOR.• PRINT HEAD STEPPER MOTOR- A STEPPER MOTOR MOVES THE PRINT

HEAD ASSEMBLY BACK AND FORTH ACROSS THE PAPER .SOME PRINTERS HAVE ANOTHER STEPPER MOTOR TO PARK THE PRINT HEAD

ASSEMBLY WHEN THE PRINTER IS NOT IN USE .PARKING MEANS THAT THE PRINT HEAD ASSEMBLY IS RESTRICTED FROM

ACCIDENTALLY MOVING , LIKE A PARKING BRAKE ON A CAR.• BELT- A BELT IS USED TO ATTACH PRINT HEAD ASSEMBLY TO THE STEPPER

MOTOR.• STABILIZER BAR – THE PRINT HEAD ASSEMBLY USES A STABILIZER BAR TO

ENSURE THAT MOVEMENT IS PRECISE AND CONTROLLED.

PAPER FEED ASSEMBLY

• PAPER TRAY /FEEDER – MOST INKJET PRINTERS HAVE A TRAY THAT YOU LOAD THE PAPER INTO.

SOME PRINTERS DISPENSE WITH THE STANDARD TRAY FOR A FEEDER INSTEAD.

THE FEEDER TYPICALLY SNAPS OPEN AT AN ANGLE ON THE BACK PRINTER ALLOWING YOU TO PLACE PAPER AS A TRADITIONAL

PAPER TRAY.• ROLLERS – A SET OF ROLLERS PULL THE PAPER IN FROM THE TRAY

OR FEEDER AND ADVANCE THE PAPER WHEN THE PRINT HEAD ASSEMBLY IS READY FOR ANOTHER PASS.

• PAPER FEED STEPPER MOTOR – THIS STEPPER MOTOR POWERS THE ROLLERS TO MOVE THE PAPER IN EXACT INCREMENT EEDED

TO ENSURE A CONTINUOUS IMAGE IS PRINTED.

• POWER SUPPLY – WHILE EARLIER PRINTERS OFTEN HAD AN EXTERNAL TRANSFORMER , MOST PRINTERS SOLD TODAY USE A STANDARD POWER SUPPLY THAT

IS INCORPORATED INTO PRINTER ITSELF.• CONTROL CIRCUITRY – A SMALL BUR SOPHISTICATED

AMOUNT OF CIRCUITRY IS BUILT INTO THE PRINTER TO CONTROL ALL THE MECHANICAL ASPECTS OF

OPERATION , AS WELL AS DECODE THE INFORMATION SENT TO THE PRINTER FROM THE COMPUTER.

• INTERFACE PORTS – THE PARALLEL PORT IS STILL USED BY MANY PRINTERS , BUT MOST NEWER PRINTERS

USE THE USB PORT . A FEW PRINTERS CONNECT USING A SERIAL PORT.

ADVANTAGES :

• LOW COST• HIGH QUALITY OF OUTPUT

• GOOD FOR PRINTING PICTURES• EASY TO USE

• REASONABLY FAST• QUIETER THAN DOT MATRIX PRINTER

• NO WARM UP TIME

DISADVANTAGES

• PRINT HEAD IS LESS DURABLE• EXPENSIVE INK CARTRIDGES

• NOT GOOD FOR HIGH VOLUME PRINTING• PRINTING SPEED IS NOT FASTER THAN LASER

PRINTER• THE INK CAUSES SOME BLURRED EFFECTS

ON THE PAPER

Laser printer

• LASER PRINTERS ARE NON IMPACT PRINTERS• IT CAN PRINT TEXT AND IMAGES IN HIGH

SPEED(600 ___ 1200 DPI)• LASER PRINTERS USE TONER(BLACK OR

COLORED POWDER INSTEAD OF INK)

Internal parts:

• LASER PRINTER HAS MANY INTERNAL PARTS. I WILL BRIEFLY GO OVER HOW A LASER PRINTER WORKS AND THE BASIC

PARTS.

BASIC PARTS OF A LASER PRINTER: 1. LASER UNIT - BEAMS AN ELECTROSTATIC IMAGE ONTO THE

DRUM 2. DRUM (OPC) - ROLLS THE IMAGE ONTO THE PAPER

3. TONER/ CARTRIDGE - TONER IS USED TO CREATE THE IMAGE 4. FUSER ASSEMBLY - HEATS AND PRESSES THE TONER ONTO

THE PAGE

Working :•

1. THE PRINTER PUTS A NEGATIVE CHARGE ON THE PAPER. 3. THE PRINTER'S LASER SPREADS A NEGATIVE

ELECTROSTATIC IMAGE ONTO A POSITIVELY CHARGED DRUM (REVERSING THE POLARITY ONLY WHERE THE IMAGE IS) 2. THE DRUM ROLLER WITH THE NEGATIVELY CHARGED IMAGE ROLLS OVER THE POSITIVELY CHARGED TONER, PICKING THE TONER ON THE IMAGE ONLY (OPPOSITES

ATTRACT). 3. THE PAPER IS THEN FEED TO THE FUSER UNIT WHERE HOT ROLLERS HEAT UP THE PAPER AND PRESS THE TONER ONTO

THE PAPER. SINCE THE TONER IS PARTLY MADE UP OF PLASTIC, THE PLASTIC MELTS AND GETS PRESSED TO THE

PAPER MAKING IT ADHERE PERMANENTLY. 4. THE FINISHED PRODUCT IS ROLLED OUT.

Advantages :

• HIGH RESOLUTION• HIGH PRINT SPEED• NO SMEARING

• LOW COST PER PAGE• PRINTOUT IS NOT SENSITIVE TO WATER• GOOD FOR HIGH VOLUME PRINTING

Disadvantages

• MORE EXPENSIVE THEN INKJET PRINTERS• IT PRINTS HIGH QUALITY IMAGES SUCH AS

PHOTOS.• THE COST OF TONER REPLACEMENT AND

DRUM REPLACEMENT IS HIGH• WARM UP TIME NEEDED

• BULKIER THAN INKJET PRINTERS

•THANKYOU MADE BY:

MUNTAHA BABARXI-A