What is Input
Anything given to the computer is called input. The data and instructions are given to the computer as input.
A method in which data is entered directly into the computer from a source.
The devices that are used for direct input are called source data input devices. Source data input devices: scanning devices (scanners), microphone, and digital camera.
A method in which data is entered into the computer after intermediate handling is called indirect input.
Examples: The data entered into the computer through keyboard and mouse.
The devices that are used to enter data and instructions into the computer are called input devices.
It is a hardware component.
It takes input from the user and converts it into a form that a computer can use.
General types of input devices:
(ii) Pointing devices
(iii) Source data-entry devices
Most popular and commonly used input devices:
- Digital camera
- Touch Pad
- Touch Screen
- Track Ball
It is mostly used to enter text and numeric type data into the computer. The buttons on the keyboard are called keys. Keys: alphabetic characters, numeric digits, and special characters, some special keys known as function keys.
A standard keyboard contains more than 100-keys.
The standard keyboard is also called QWERTY keyboard.
Parts of Keyboard:
- Function keys
- Main keyboard
- Numeric keys
- Additional keys
Control the cursor or pointer on the screen and to give commands to the computer.
As a user moves a mouse, the pointer on the screen also moves. Connected with the computer by a cable or wireless connection, connected to the USB port on the system unit.
One wheel and 2 or 3 buttons. Also allows the user to create graphics such as lines, curves, and freehand shapes, on the screen.
It has a small rubber or metal ball at the bottom.The movement of the pointer depends on the rotation of the ball. The mouse pad is a small rectangular rubber pad.Rarely used.
No ball at the bottom.It uses laser technology to detect the mouse movement.
Nowadays, it is commonly used in personal computers (PCs).
Track Ball performs functions like a mouse
Have Moveable ball on its top, rotated or rolled with fingers (or palm of the hand) to move the pointer on the screen.
Like a mouse, a trackball also has buttons used to send the commands to the computer.
Availability: with laptop computer, fixed on its keyboard. Also available as a separate input device.
Pressure-sensitive pointing input device.
Also known as trackpad.
Stationary device like trackball but no moving parts. It is a small, flat surface (or sensitive pad) over which a user slides fingertip to move the pointer on screen.
One or two buttons located near the pad. These buttons work like mouse buttons.
Normally used with laptops and are built-in on their keyboards
Touch-sensitive display device.
Input is given to the computer directly by touching the screen with the user’s fingertip or stylus.
Uses: to make a selection from a menu of choices displayed on the screen.
Examples: mobile computers and mobile devices such as smartphones and tablets. Laptop screens, Automated Teller Machines (ATM) interface.
Multi-touch Screens. For example, a user can use his/her two or more fingers to enlarge or rotate an image on the screen
Digitizer or Graphics Tablet
Some computers do not have touch screens. In these computers, data can be entered using stylus or puck through graphics tablet.
A graphics tablet (digitizer) consists of a flat, rectangular, electronic board (or pad).
The stylus or puck is connected to the graphics tablet by a wire.
Applications: mainly used for making maps and engineering drawings. It makes it easy to enter free-hand drawing into the computer.
A graphics tablet can be attached to a computer.
Each location on the rectangular board points to the corresponding position on the computer screen.
The input device puck or stylus or cursor looks like a mouse.
Purpose of Cursor
To copy an image.
Tracing old images.
Takes (captures) pictures and stores them in digital form.
The number of pictures that a digital camera can store depends upon its memory size.
Flash memory cards are used inside digital cameras to store pictures.
- An LCD for viewing the pictures.
- Also record moving videos with sound.
Today, mobile phones (smartphones) and other mobile devices have built-in cameras.
The pictures/videos stored in the camera’s memory card can be transferred to a computer or other computing device using a wired or wireless connection.
Advantages of Digital Camera
- Making photos is inexpensive and fast because it does not require any film processing.
- The pictures taken by a digital camera can directly be inserted into the documents