INPUT DEVICES

INPUT DEVICES

They are devices used for sending, transferring or entering data into the computer system. It is where human readable language is converted to computer readable language.

   But INPUT is the process of sending, transferring and entering data into the computer system.

Examples of input devices are:

Keyboard, Mouse, Scanner, Joystick, Trackball, Light pen, Digital camera etc

THE KEYBOARD

This is one of the input devices used for entering or keying data into the computer system.

    It is an essential part of the computer hardware.

            TYPES OF KEYBOARD

There are three types of keyboard

1.     The standard keyboard

2.     Enhance keyboard

3.     Window keyboard

THE STANDARD KEYBOARD

They came after the XT keyboard and have 82 to 85 keys. The functional keys of the standard keyboard ranges from F1 to F10.

  THE ENHANCED KEYBOARD

They can be referred to as a computer keyboard. It has about 102 t0 105 keys. The functional keys of the enhanced keyboard ranges from F1 to F12. It is called the computer keyboard.

 THE WINDOW KEYBOARD

It was an improvement on the enhanced keyboard. They have start button. Example is the on-screen keyboard.

PARTS OF KEYBOARD

1.     FUNCTIONAL KEYS: They are keys used for sending commands to the computer, depending on the type of application package one is using they are from F1 – F12.

2.     ALPHA –NUMERIC KEYS: They are used for entering both alphabets and number as well as symbol e.g. Alphabets(A-Z) Number(0-9) Symbols(.,;:+<> etc)

3.     NUMERIC KEYS: They key are used for entering numbers or numeric symbols to the    computer.

4.     SPECIAL KEY: They perform special functions in the computer like, the Space bar, Escape key, Enter key control key etc.

5.     CURSOR CONTROL KEYS: They are keys used to control the movement of the cursor in the computer environment when the mouse is not active.

6.     EDITING KEYS: They are used for editing texts and objects e.g. Backspace, Delete key etc.

7.      ARROW KEYS /DIRECTIONAL KEYS: They are used to indicate directions Thus, moving object up, down, left and right in the computer.

THE KEYS IN THE KEYBOARD

1.     THE ENTER KEY: It is used to move the cursor to the beginning of a new line while typing.

2.     SPACE BAR: It is used for creating space while typing. It is the longest key in the keyboard.

3.     BACKSPACE:  It is used to clean characters while typing in the computer.

4.           SHIFT KEY: This key is used to select capital letters when pressing the alphabet characters or select the characters above other non- alpha keys. It can also enable one to highlight text with the help of the arrow keys.

5.     CAPS LOCK: It is used for capitalization thus changing from capital letter to small letter or from small letter to capital letter.

6.           TAB KEY: It is used to move forward through options in a dialog box. It is also used for making paragraphs while typing in the computer.

7.           HOME KEY: It takes the cursor to the beginning of a line in a document.

8.           NUMBER LOCK: It is used to activate or deactivate numeric keypad.

9.           PRINT SCREEN: It is use for printing and copying the screen of the program window.

10.      SCROLL LOCK: It keeps all the selected text highlighted while you scroll.

11.      ESCAPE KEY: This key is used to cancel every unwanted command in the computer.

12.        CONTROL KEY: It is used in conjunction with other keys like Alphabetic keys and function keys for indicating commands.

13.      ALTERNATIVE KEY:  It is used to alternate keyboard function. It can also be used to activate the menu bar of a program.

14.        DELETE KEY:  It is used to delete text and objects in the computer.

15.        INSERT KEY:  It is used to insert words to the computer.

16.        PAGE UP KEY:  It is used to move up the page on the screen.

17.        PAGE DOWN KEY: It is used to move down the page on the screen.

18.        END KEY: It takes the cursor to the end of a line. It is also used to deselect a highlighted text or objects.

FUNCTIONS OF KEYBOARD

1.     A keyboard is used to input data into the computer.

2.     A keyboard can be used to input commands and instructions to a computer.

3.     A keyboard provides quick access to menus on the computer.

MOUSE

The mouse is an input device. It is a hand held pointing device which makes it easy to use application packages efficiently. In other words, mouse is one of the input devices used in directing the cursor around the screen in the computer environment for the execution of command. It is usually oval in the shape but can be any other shape. The size varies. It is used to select commands, words, pictures or icons on the computer screen much more quickly than the keyboard.

    Mouse is used to perform the following:

·         Pointing

·        Clicking

·        Double clicking

·        Dragging

·        Right clicking

·        Scrolling

1 . POINTING: It means positioning the mouse pointer on a desired item or area on your screen.

2 . CLICKING: It means pressing and releasing either the left or the right mouse button once, for execution of a command.

3 . DOUBLE CLICKING: This is the pressing and releasing the left button of the mouse twice simultaneously in a rapid succession.

4 . DRAGGING: This is the clicking of the left button of the mouse and holds it down while moving the mouse pointer to a desired destination.

5 . RIGHT CLICKING: It is the pressing of the right mouse button in other to select a command.

6 . SCROLLING: It is the act of moving up and down the page while pressing the centre button of the mouse.

FUNCTIONS OF MOUSE

1 It is used to delete a text at an instant.

2 It is used to insert a value into a worksheet.

3 It is used to highlight a text or object.

4 It is used to select a menu

5 It is used to move a text or object.

          TYPES OF MOUSE

There are two types of mouse, they are:

1 .Mechanical Mouse

2 .Optical  Mouse

MECHANICAL MOUSE: It contains a rubber ball that makes the cursor move      according to the rotation of the internal rollers. Though mechanical mouse are very robust, they need frequent cleaning to remove the dirt on the rollers and the ball for smooth running. Mechanical mouse can also be called a Ball mouse.

OPTICAL MOUSE: The type of mouse works well on several surfaces excluding bright surfaces and in bright lights. Computer mouse uses three types of interfaces.

·  The serial type (which comes with 9 pin & type plug)

·  The PS/2 type (which is a circular DIN connector and is easy to setup)

·  The USB interface mouse (which can be plugged into any USB port) it is very flexible and can be removed when the computer is on.

But note that we have the cable mouse and cordless mouse as types of mouse.

The cordless mouse can also be called a wireless mouse.

SCANNER

Scanner is one of the input devices that can be attached to a computer. It is designed to send data/ information inform of graphics and images to the computer.

         

              FUNCTIONS OF SCANNER

1  It is used to send data or information from paper into the computer.

2  It is used to send images (pictures) into the computer.

3  It is used to photocopy any text or diagrams into the computer.

SCANNING

Scanning is the act of sending or transferring data/information in form of graphics and images to the computer.

    HOW TO SCAN IN MICROSOFT WORD

1 .Open any file

2 .Make sure that the scanner is connected properly and the image is place face down inside the scanner

3 .Click insert from the menu bar

4 .Point to picture

5 .Click “from scanner or camera”

6 .Click scan in the dialog box

7 .The scanner will warm up for few minutes and display a dialog box

8 .Click preview button

9 .Use the rectangle like line to select the size of image you want to scan

10  .Click scan button

11  .Click close or press off to close the dialog box

12  .You can edit the picture, by right clicking on the picture, choose edit picture, click layout, choose the type of  layout

13  .Click ok.

Note: The above procedure applied to PowerPoint and Microsoft excel.

  HOW TO SCAN IN COREL DRAW

1 .Open Corel draw

2 .Insert the picture

3 .Click file

4 .Point to acquire image

5 .Click acquire

6 .In the dialog  box, click preview  button

7 .Use the rectangle like line to select the size of the image you want to scan

8 .Click scan button

NOTE: The scanned image will be automatically placed in the printable page of the Corel draw. Note also that this method applied to PageMaker. 

OTHER INPUT DEVICES ARE:

·  LIGHT PEN:  It is used to write and draw on the computer screen.

·  JOY STICK:  It is used for playing computer games.

·  MICRO PHONE:  It   coverts sounds in air into an electrical signal.

·  DIGITAL CAMERA:  It is used for inserting pictures to the computer.

·  CARD READER: It is used to insert memory cards for data storage etc.