DSB INTERNATIONAL PUBLIC SCHOOL RISHIKESH COMPUTER Chapter-1 Input and Output Devices

Input Device An input device is a hardware or peripheral device used to send data to a computer. An input device allows users to communicate and feed instructions and data to computers for processing, display, storage and/or transmission. Some of the commonly used input devices are:

Keyboard

Keyboard is the most common and very popular input device which helps to input data to the computer. The layout of the keyboard is like that of traditional typewriter, although there are some additional keys provided for performing additional functions.

Mouse

Mouse is the most popular pointing device. It is a very famous cursor-control device having a small palm size box with a round ball at its base, which senses the movement of the mouse and sends corresponding signals to the CPU when the mouse buttons are pressed.

Joystick

Joystick is also a pointing device, which is used to move the cursor position on a monitor screen. It is a stick having a spherical ball at its both lower and upper ends. The lower spherical ball moves in a socket. The joystick can be moved in all four directions.

Light Pen

Light pen is a pointing device similar to a pen. It is used to select a displayed menu item or draw pictures on the monitor screen. It consists of a photocell and an optical system placed in a small

tube.

Track Ball

Track ball is an input device that is mostly used in notebook or laptop computer, instead of a mouse. This is a ball which is half inserted and by moving fingers on the ball, the pointer can be moved.

Scanner

Scanner is an input device, which works more like a photocopy machine. It is used when some information is available on paper and it is to be transferred to the hard disk of the computer for further manipulation.

Microphone

Microphone is an input device to input sound that is then stored in a digital form.

The microphone is used for various applications such as adding sound to a multimedia presentation or for mixing music.

Touch Screen

A touch screen is a computer screen that can be used by touching it with a finger or a stylus pen. This technology is generally used in ATMs, mobile phones, tablets ,etc.

Webcam it is an input device connected to the computer and the internet that captures still picture or motion video.

Monitors

Monitors, commonly called as Visual Display Unit (VDU), are the main output device of a computer. The output which we get on a monitor is called soft copy output.

FPD CRT

There are two kinds of viewing screen used for monitors.

 Cathode-Ray Tube (CRT)  Flat-Panel Display

Printers

Printer is an output device, which is used to print information on paper. The printed output produced by a printer is often called a hard copy, which is the physical version of an electronic document. While some printers can only print black and white hard copies, most printers today can produce color prints.

Dot Matrix Printer

It prints characters as combination of dots. Dot matrix printers are the most popular among serial printers. These have a matrix of pins on the print head of the printer which form the character.

Advantages

 Widely Used  Other language characters can be printed

Disadvantages

 Slow Speed  Poor Quality  Laser Printers

These are non-impact page printers. They use laser lights to produce the dots needed to form the characters to be printed on a page.

Advantages

 Very high speed  Very high quality output  Good graphics quality  Supports many fonts and different character size

Disadvantages

 Expensive  Cannot be used to produce multiple copies of a document in a single printing

Inkjet Printers

Inkjet printers are non-impact character printers based on a relatively new technology. They print characters by spraying small drops of ink onto paper. Inkjet printers produce high quality output with presentable features.

It can print both colored as well as black ink output.

Advantages

 High quality printing  More reliable

Disadvantages

 Expensive as the cost per page is high  Slow as compared to laser printer

Speakers

This is output device is used to generate audio output. It is generally used with the computers to play music or sound.

Plotter

These are generally used by the engineers and architects for generating high quality graphical outputs. Q1.Tick the correct option:

i. Device which is used to enter images or pictures in the computer is called: a. Scanner b. Printer c. Mouse b. ii. Which type of printer is fasterand gives high quality output? a.Laser printer b. Inkjet printer c. Dot matrix printer iii. Which technology is used in cordless mouse?

a.Touch b.Bluetooth c. Wi-Fi iv. ______is generally used by engineers and architects for printing.

a.Laser Printer b. Plotter c .Inkjet printer

v. Which among these is a type of monitor?

a.DVD b. LCD c .CVD

Q2.Write True or False:

i. Keyboard is an input device. ( ) ii. Microphone is used to record sound in the computer. ( ) iii. VDU stands for Visual Display Unit. ( ) iv. The speed of Dot Matrix printer is measured in ppm. ( ) v. Inkjet printer cannot print coloured output. ( )

Q3.Fill in the Blanks. ( Microphone, ppm , Data, Optical, Instructions, Touch Pad) i. Input device are used to give ______and ______to the computer system. ii. ______is used to give vocal instructions to the computer. iii. A mouse that uses light beam to track the movement is called______mouse. iv. ______is generally used in Laptops and Notebooks. v. Speed of the Laser printer is measured in ______. Q4.Answer the following question:

Q1 Name the output device which produces the soft copy output.

Q2. What do you mean by input devices? Write three examples.

Q3. What is the difference between Laser and Inkjet printers?

Q4. What do you understand by hard copy and soft copy output?