Keyboard and Mouse
The simplest input devices are the keyboard and the mouse. A keyboard is used to input data manually into a computer. The standard keyboard that is used throughout the UK is the QWERTY keyboard. However there are many different keyboards that are used to suit other countries with their languages. A mouse is a pointing device which is used to move a pointer around the screen and to select options by clicking. There are two main types of mouse, mechanical and optical. A mechanical mouse has a rolling ball and the computer senses its position on a flat surafceand requires a mouse mat, where as an optical mouse uses a light sensor to detect motion and doews not need a mouse mat.
Touch-sensitive devices
As technology has improved the invention of touch-sensitive devices has evolved, which only requires the human hands to work. Concept keyboards and touch screens are examples of touch sensitive devices. Concept keyboards are divided into areas which are labelled to suit the actual use. Special software then interprets the key press for the computer. This type of input device can also be used by children and people with disabilities. A touch screen senses when an area of the screen has been touched, either by wires embedded in the screen or by patterns of infra-red light beams. Software then interprets the signal. PDAs and graphics tablets are examples of touch screens.
Speed Recognition
This is where the user speaks into a microphone. The sounds of words are compared with a dictionary of sounds and converted into computer-readable text using speech recognition software.
Automated input
Card Readers - For example magnetic strip cards can be swiped through a card reader machine. These are easy to read, but can't hold much data. The magnetic strip is also easy to scratch.
Smart Card - A smart card such as a chip and PIN credit card. The computer chip built into the card can hold more data than a strip card.
RFID - This stands for Radio Frequency Identification which uses radio waves to transmit a unique serial number as a form of ID for objects.
Scanners - These are used to turn paper-based pictures or documents into digital images. Examples are flat-bed scanners, barcode scanners, hand-held scanners.
OMR - This stands for Optical Mark Recognition which uses a light beam to sense the position of the pencil or other marks on a piece of paper.
OCR - Optical Character Recognition is where a paper-based document is scanned and each part of the image is compared to a dictionary of known letter shapes.
Barcode Readers - A pattern of black and white lines which represents a number. They are often used in electronicpoint of sale. The barcode is scanned and the product number acts as a product key for the product in the stock database.
Out of all of these input devices the mouse is my favourite input device because without it our life would be much harder. The mouse is used as a pointing device and allows you to click on icons and options. It is much easier to just get to a program by just clicking it's icon than having to use only the keyboard tabs to navigate on the computer, which would take much longer and would become a headache if you didn't know all the shortcuts.
