Input Devices

Input Devices - A peripheral used to get data and instructions into the computer system.

General
Mouse - It works by detecting the movement of the X and Y axis, it also has 2 or 3 buttons, left, right and scroll (middle).

Microphone (Voice Recognition) - Computer detects speech which turns it into text, using a microphone and sound card with appropriate software.

Graphics Tablet - Allows Graphics to be drawn into a computer by hand. It is a flat board is connected to the computer. It uses a stylus to detect the movement across the surface of the tablet. adding pressure to the surface operates a micro switch, which allows the computer to record movement. The board contains electronics to detect the position of the stylus tip.

Keyboard - Used to enter text into the computer system. the electrical components scan the rows of keys to detect the pressing of a key or key combination. When a key is pressed it sends the key's scan code to the computer. The software in the computer translates the scan code into ASCII or Unicode.

Touch Sensitive Screens - Is a type of visual display which allows the user to interact with an application. The screen has been adapted by having horizontal and vertical infrared beams, the breaking of these beams allows the system to detect where movement is on the screen.

Digital Still Camera - A digital camera is an electronic device used to capture images and videos onto an SD Card which then allows you to upload to your computer by USB.

Readers
Smart Card Reader - A smart card is a plastic card the size of a credit card that holds an integrated micro chip. The chip contains a microprocessor, which contains a small amount  of ROM and a small amount of RAM.

Magnetic Stripe Reader - Magnetic stripe readers read information encoded magnetically in a stripe on the back of a plastic or cardboard card. The stripe is used to encode binary data. They are often used on Debit and Credit Cards.

Bar Code Reader - Is an electronic device for reading bar codes printed on items such as cans. A bar code is a sequence of white and black bars that encodes information such as a product identifier. The reader consists of a light source, the light source illuminates the black and white bands, light is reflected from the white and not from the black. the pattern of the bar code is then converted from optical form to electrical form. This is done by photo electronic detectors.

Optical Mark Reader - An optical mark reader senses marks placed on predefined positions on a form. The form is passed under a light source and the intensity of reflected light from each row of the form is measured and converted by photoelectric sensors into an electrical equivalent.

Optical Character Recognition - Uses an optical scanner to input images of text then analyse the resulting digital images to recognise the characters.

Radio Frequency Identification - Uses radio frequencies to transmit data, a timing signal and energy between the reader and an RFID device.

Scanners
Finger Print Scanner - A fingerprint reader is a security device that takes a picture of a finger so that the pattern of the ridges and valleys in the image can be analysed. It consists of a sensor and decoder circuitry to analyse the captured image data and output it on a computer against stored fingerprint data in a database.

Flatbed Scanners - Usually has a glass plane illuminated from beneath by a bright light, often xenon or cold-cathode fluorescent. An array of light detecting sensors spanning the width of the glass pane is moved slowly with the light source along the glass plane to pick up light reflected from anything placed on top of the plane. Coloured scanners usually use three different types of arrays.

Retina Scanner - Consists of a low energy infrared light source which is directed onto the retina of the eye. Each persons retina is unique. The photoelectric sensors convert the results into readable form on a computer.

Iris Scanner - Is a flat circular coloured membrane suspended vertically in the aqueous of the human eye. It uses a camera which is sensitive to infrared light and is placed no more than 3 ft from the subject to capture the image of the iris and compare this to data in a database .