A PRESENTATION ON THE TOPIC ON INPUT AND OUTPUT DEVICES
INPUT DEVICE :- An input device is a piece of computer hardware equipment used to provide data and control signals to an information processing system such as computer or information appliance.
Major input devices :- Some of the major input devices are:- KEYBOARD MOUSE JOYSTI CK OMR( OPTICAL MARK READER) LIGHT PEN POINT OF SCALE TERMINAL(POS TERMINAL) BCR( BAR CODE READER) OCR (OPTICAL CHARACTER READER) MICR( MAGNETIC INK CHARACTER READER)
Keyboard is a flat piece of plastic board many buttons arranged on it . These buttons are called keys. The keyboard help in inputting the data to the computer . There are following functions keys on a keyboard like F1 to F12 , numeric keys 0 to 9 and alphabet keys A to Z . It consists caps lock key, num lock key ,shift key ,back space key ,space bar key and enter key etc. Standard keys on a keyboard is 101. KEYBOARD:-
MOUSE :- Mouse is a pointing device it consist three buttons. Left button right button and scroll button . Left button is used to select an object , right button is used to excess the properties of an object and scroll button is used to scrolling the page up and down. Mouse are basically used in desktop computer system when placed on a fixed space than we use mouse.
JOYSTICK:- Joystick is a pointing device most common used to play animated games on a micro computer. Joystick works on the same principal as a trackball. Joysticks are often used to control video games and usually have one or more push buttons whose state can also be read by the computer.
OPTICAL MARK READER:- Optical mark reader is a special optical scanner device which can be used to recognise the type of mark made by pencil or pen. This device is used as academic and examination centres to grade aptitude test. Where candidate mark the correct answers on a special sheet of paper having multiple circles. These answer sheets are the directly read by the optical mark reader and the corresponding information is sent to a CPU for processing.
LIGHT PEN: Light pen is a pointing device that can be a used to choose a displayed menu option or to draw picture on the screen. It consist of a photocell and an optical system placed in a small tube as the user moves tip on the pen over the surface. It is able to detect the light coming from a limited field of view. A light pen is also useful for graphic , the user at computer added design terminal can draw directly on the screen with the pen.
POINT OF SCALE TERMINAL (POS TERMINAL ):- It is a higher version of the bar code reader , also used in departmental stores. In this case, the salesman move about, carrying with them a barcode reader and a laptop computer. When a customer wants to purchase something, the salesman with the aid of the barcode reader and the laptop computer, decodes the detailed information in printed on the barcode of that product.
BCR (BAR CODE READER):- Various commodities available in the market have a sequence of black and white lines of varying thickness, closely placed together printed on the cover . These lines which are known as barcodes . Barcodes contains the various information about the product, e.g. name of the product, manufacturing date, producer name, expiry date, cost of production etc.
OCR(OPTICAL CHARACTER READER):- Optical character reader is a optical scanner used to scan documents place under them by examining each character present in the document and matching it the character may be either typed or hand return. In case of hand return characters special care has to be taken to ensure that the characters are of standard size , line making up the character are connected. OCR devices are particularly used for large volume application such as reading zip codes in postal service and printing bill of credit card.
MICR(MAGNETIC INK CHARACTER READER:- It is popularly used in banks for verifying important documents like drafts, cheques etc. At the bottom side of such documents, a set of symbols are printed with magnetized ink.
OUTPUT DEVICES:- An output device is any device used to send data from a computer to another device or user . Most computer data output that is meant for humans is in the form of audio or video. They perform the following function:- Receive result from memory Convert data into human readable form Display result to the user
DIFFERENT TYPES OF OUTPUT DEVICE:- MONITOR PRINTER IMPACT PRINTER NON –IMPACT PRINTER SPEAKER AND HEADSETS PLOTTER MULTIMEDIA PROJECTER
MONITOR:- T he monitor is the most common and the most important output device. It is also called a visual display unit. The output viewed on a monitor is called a soft copy. The monitor is a visual display device to present output information in the form of text, graphic, or video on the monitor screen.
PRINTERS:- Printers are used to produce hard copy output. They print processing results on paper. Printers are divided into two main categories:- Impact printer Non- impact printer
IMPACT PRINTERS:- The printer that print the character by striking against the ribbon and into the paper is called impact printer. There are two types of impact printer. Character printer line printer
CHARACTER PRINTER :- These printer print one character at a time is called character printer . For example Dot matrix printer. They form character and all kind of image as pattern or dots.
LINE PRINTER:- These printer print one line at a time. So it is called as line printer. These printer use impact technology. There is mechanical contact between head and a paper . These are first printer having speed in the range of 3000 lines per minutes.
NON – IMPACT PRINTERS:- Non impact printer that prints the character without striking against the ribbon and on the paper is called non impact printer. These printer print a complete page at a time so also called page printer . There are two types of non impact printer. Inkjet printer laser printer
INKJET PRINTER:- These printer prints the character by spraying the paper with electrically charged ink . They give better quality than character printer. They are cheaper than laser printer. LASER PRINTER:- These are based on laser technology with high speed and high quality printing .In these printer a laser beam is used to write the image on a paper.
SPEAKER AND HEADSETS:- Speaker and head sets produce sound output. We can listen recorded voices, sounds or music with the help of speaker or headset. Speaker produce sound output with the help of sound card.
PLOTTER:- A plotter is an output device used to produce image quality graphics in a variety of colors. Plotter are used to print large maps, architectural drawings, graphs and charts. Plotter are used o draw different design of building or internal structure of machines. Plotters offer the fastest way to efficiently produce very large drawing or color high resolution graphics. Engineers and architects use plotters.
DRUM PLOTTER:- In drum plotter both paper and drum move to produce the output. The plotter was the first output device to print graphic and large engineering drawings. FLATBED PLOTTER In this plotter the paper is fixed and drum moves. Flatbed plotters have a large horizontal surface on which the paper is placed.
MULTIMEDIA PROJECTOR:- Multimedia projector is used to produce computer output on a big screen. These are used in meeting rooms or in classroom of educational institutes. Since the output produced by multimedia projector is displayed on a large screen, it can be viewed by a large number of people in a hall, meeting /conference room or a class room .Mostly teachers used data projector in class room for delivering lectures.