INTRODUCTION TO COMPUTERINTRODUCTION TO COMPUTER

CHAPTER N0 2CHAPTER N0 2

INPUTINPUT & &

OUTPUT OUTPUT DEVICESDEVICES

INSTRUCTORINSTRUCTOR:: ADEELADEEL ANJUM ANJUM

OUTPUT DEVICESOUTPUT DEVICES

An output device is used by computer to communicate its An output device is used by computer to communicate its results or message to the outer world.results or message to the outer world.

A device which transfers the data or program from computer A device which transfers the data or program from computer memory to outer medium. For example the monitor or printer. memory to outer medium. For example the monitor or printer.

Almost every computer will include a device that outputs data Almost every computer will include a device that outputs data in human readable form.in human readable form.

A small computer will only have cathode ray tube (monitor) on A small computer will only have cathode ray tube (monitor) on which the output appears temporarily.which the output appears temporarily.

Example:monitor,printer,plotter,speakers,VCR, etc.Example:monitor,printer,plotter,speakers,VCR, etc.

What are two categories of output data?What are two categories of output data? Soft copy and hard copy are two categories of output data.Soft copy and hard copy are two categories of output data. SOFT COPYSOFT COPY

it is data that is shown on display screen or is in audio or video formit is data that is shown on display screen or is in audio or video formit exist only electronically. it cannot be touched. its like music.it exist only electronically. it cannot be touched. its like music.

HARD COPYHARD COPYit is printed output. for example print out.it is printed output. for example print out.

MONITORMONITOR There are two types of monitor CRT and FLAT PANEL.There are two types of monitor CRT and FLAT PANEL. CRT (cathode ray tube)CRT (cathode ray tube)

The monitor is referred to as the CRT i.e. the cathode ray The monitor is referred to as the CRT i.e. the cathode ray tube. It is very popular output device as far as the tube. It is very popular output device as far as the communication with the computer is concerned. The monitor communication with the computer is concerned. The monitor is similar to a television screen and in fact for some is similar to a television screen and in fact for some computers the television screen can be used as the monitor. computers the television screen can be used as the monitor. In 1897 German physicist invented CRT.In 1897 German physicist invented CRT.

FLAT PANELFLAT PANELIt is made up of two plates pf glass separated by a layer of a It is made up of two plates pf glass separated by a layer of a substance in which light is manipulated. It use liquid crystal display substance in which light is manipulated. It use liquid crystal display (LCD) technology.(LCD) technology.It is much thinner ,weight less,portable,consume less power as It is much thinner ,weight less,portable,consume less power as compares to CRT.compares to CRT.

PRINTERPRINTER Printer is output device used to prepare permanent Printer is output device used to prepare permanent

document on a paper for human use.document on a paper for human use. A computer peripheral that puts text or a computer A computer peripheral that puts text or a computer

generated image on paper or on another medium.generated image on paper or on another medium. Printer can be categorized in several ways the most Printer can be categorized in several ways the most

common distinction common distinction IMPACT IMPACT and and NON-IMPACT. NON-IMPACT.

IMPACT PRINTERIMPACT PRINTER

Is the method used by the conventional typewriters? In Is the method used by the conventional typewriters? In some type of impact printing a metal "hammer" embossed some type of impact printing a metal "hammer" embossed with a character strikes a print ribbon, which presses the with a character strikes a print ribbon, which presses the characters image into paper. In other types the hammer characters image into paper. In other types the hammer strikes the paper and presses it into the ribbon characters strikes the paper and presses it into the ribbon characters created through impact printing can be formed by either a created through impact printing can be formed by either a solid font or dot matrix printing mechanism.solid font or dot matrix printing mechanism.

TYPES OF IMPACT PRINTER.TYPES OF IMPACT PRINTER.

LINE PRINTERLINE PRINTER

DOT MATRIX PRINTERDOT MATRIX PRINTER

DAISY WHEEL PRINTERDAISY WHEEL PRINTER

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LINE PRINTERSLINE PRINTERSAny printer that prints one line at one time, as opposed to one Any printer that prints one line at one time, as opposed to one character at a time. Line printer typically produced the 11 by 17 character at a time. Line printer typically produced the 11 by 17 inch "computer" printout. They are high-speed devices and are inch "computer" printout. They are high-speed devices and are often used with mainframes, minicomputers, or networked often used with mainframes, minicomputers, or networked machines rather than with single user system. Types of line machines rather than with single user system. Types of line printers include chain printers and band printer.printers include chain printers and band printer.

DOT MATRIX PRINTERDOT MATRIX PRINTERAny printer that produces character made up of dots using a wire Any printer that produces character made up of dots using a wire pin printed head. The quality of output from a dot matrix printer pin printed head. The quality of output from a dot matrix printer depends largely on the number of dots in the matrix, which depends largely on the number of dots in the matrix, which might be low enough to show individual dots or might be high might be low enough to show individual dots or might be high enough to approach the look of fully formed characters. The enough to approach the look of fully formed characters. The number of pins in the printer head typically, 9 or 24 often number of pins in the printer head typically, 9 or 24 often categorizes dot matrix printers.categorizes dot matrix printers.

DAISY WHEEL PRINTERDAISY WHEEL PRINTERDaisy wheel printer are some times called letter quality printer Daisy wheel printer are some times called letter quality printer because they are often used to produce attractive because they are often used to produce attractive correspondence. The D.W.P is a flat circular device made of correspondence. The D.W.P is a flat circular device made of metal with character embossed on it. As this wheel spins at a metal with character embossed on it. As this wheel spins at a very high speed the hammer hits the specific character against very high speed the hammer hits the specific character against the ribbon which presses against the paperthe ribbon which presses against the paper.. 6

NON – IMPACT PRINTINGNON – IMPACT PRINTING

Does not depend on the impact of metal on paper. In fact Does not depend on the impact of metal on paper. In fact no physical contact at all occurs between the printing no physical contact at all occurs between the printing mechanism and the paper. mechanism and the paper.

TYPES OF NON IMPACT PRINTERSTYPES OF NON IMPACT PRINTERS

LASER PRINTERLASER PRINTER INK JET PRINTER INK JET PRINTER THERMAL PRINTERTHERMAL PRINTER PLOTTERPLOTTER

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LASER PRINTERSLASER PRINTERS An electro photographic printer that is based on the An electro photographic printer that is based on the

technology used by photocopiers. A focused laser beam and a technology used by photocopiers. A focused laser beam and a rotating mirror are used to draw an image of the desired page rotating mirror are used to draw an image of the desired page on a photosensitive drum. This image is converted on the on a photosensitive drum. This image is converted on the drum into an electrostatic charge, which attracts and holds drum into an electrostatic charge, which attracts and holds toner. A piece of electro-statically charged paper is rolled toner. A piece of electro-statically charged paper is rolled against the drum, which pulls the toner away from the drum against the drum, which pulls the toner away from the drum and onto the paper. Heat is then applied to fuse the toner to and onto the paper. Heat is then applied to fuse the toner to the paper. Finally, the electrified charge is removed from the the paper. Finally, the electrified charge is removed from the drum and the excess toner is collected. By omitting the final drum and the excess toner is collected. By omitting the final step and repeating only the toner application and paper step and repeating only the toner application and paper handling steps, the printer can make multiple copies. Laser handling steps, the printer can make multiple copies. Laser printer run with a software called page description language printer run with a software called page description language (PDL).It has its own CPU,ROM,RAM.(PDL).It has its own CPU,ROM,RAM.

THERMAL TRANSFER PRINTERTHERMAL TRANSFER PRINTER It is a kind of non-impact printer. In electro-thermal printing, It is a kind of non-impact printer. In electro-thermal printing,

characters are burned on to a special paper by heated rods on characters are burned on to a special paper by heated rods on a print heat. They transfer ink from a wax-based ribbon onto a print heat. They transfer ink from a wax-based ribbon onto plain paper. These printers can support high quality graphic.plain paper. These printers can support high quality graphic.

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INK – JET PRINTERINK – JET PRINTER

It is a kind of non-impact spray small dots of electrically It is a kind of non-impact spray small dots of electrically charged ink onto a paper to form images. Ink jet printers charged ink onto a paper to form images. Ink jet printers are flexible enough to be used as plotters.are flexible enough to be used as plotters.

PLOTTERPLOTTER The plotter is an output device. It is an example of non The plotter is an output device. It is an example of non

impact printer. plotters are designed to produce large impact printer. plotters are designed to produce large drawing or images such as construction plan for buildings.drawing or images such as construction plan for buildings.

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