ICT- Input Devices

Input Devices

Keyboard

• uses a standard layout, referred to as QWERTY
• depends on the human operator for speed of input
• is prone to human error since all data is keyed-in
• is used to enter text into a computer
• Some keyboards (e.g. EPOS & ATM) are specially designed for specific applications. They may have fewer keys and an emphasis on numeric keys.
• Concept keyboards have keys with pictures to words that can be programmed to carry out specific instructions.

Tracker Pad

• known as a 'touch-sensitive' pad- it can sense touch from a finger
• used as an alternative to a mouse on a laptop computer
• ideal for a portable device as it can be used in a confines space
• Movement on the pad controls the cursor, which allows the user to select options from the menus, select icons and position the cursor

Mouse

• is also referred to as a 'pointing device'
• is easy to use and inexpensive compared to other input devices
• is designed to fit under the human hand
• can contain 2 or 3 buttons which are used to make selections on the screen
• Experienced users may find using a mouse slow compared to using 'hot keys'.
• Some mice use a mouse ball and built in movement sensors. other mice use infrared or wireless technology. A tracker ball is an alternative to a mouse.

Joystick

• allows the user to control an object on the screen be manoeuvring a small lever in different directions
• senses movements which are converted to co-ordinates
• usually has pre-programmed buttons to allow actions to be carried out
• is used to play computer games

Touch Screen

• A special type of screen which reacts to human touch
• minimal user training required
• no additional hardware required
• used in banks, tourist offices, museums and supermarkets
• used in hand-held game consoles, PDAs and mobile telephones
• When the user's finger touches the screen, vertical and horizontal beams of light are sensed and then converted into a co-ordinate. You can drag your finger across the screen to perform 'drag and drop' operations.

Microphone

• designed to input sound or human voice into a computer system
• used in voice- recognition applications
• natural form of communication for humans
• background noise can interfere with spoken words
• can record music and store digital format.
• The spoken word can be converted to text or the computer can interpret spoken commands. the user can record and store words and phrases in a database which can be used to recognise words and phrases in future.
• Voice recognition is helpful for users with less mobility: they can use their voice instead of a mouse or other input device

Digital Camera

• stores pictures on a memory card
• a small liquid crystal display (LDC) screen is attached to view pictures taken immediately
• pictures can be downloaded to a computer connected to the camera with a USB cable or a wireless connections
• Memory cards have a typical capacity of 4GB, which allows around 1000 pictures to be stored in medium resolution.
• Digital camera can also capture short video clips that last a couple of minutes.

Scanner

• A scanner converts a hard copy of pictures or text into a digital image. Beams of bright light are passed over the image, which is recognised as a series of dots on a page.
• once an image has been scanned, it can be saved and edited using standard software
• if text is scanned it can be recognised by a word processor using optical character recognition (OCR) software.
• text can be edited and saved electronically

Graphics Digitiser

• a flat electronic sensitive surface that captures the image drawn with a stylus pen
• allows the user to record a hand-drawn image in a computer system
• the image drawn can be imported to a graphics package for further editing