Input devices Flashcards
Hardware
A physical components of a computer.
Input device
Is a hardware device allows a user to enter data into a computer system.
Automatic input device
Automatically will read data and input it into a computer system. E.g. temperature sensor
Manual input device
Need a user to physically enter the data into a computer system. E.g. keyboard
Software
Programs and instructions run on a computer.
Mechanical keyboard
They have a set of keys that can be pressed to enter the data. Include letters, numbers and symbols. Also special command function keys are programmed(arrows, print screen…)
Virtual keyboard
On-screen keyboard. They are created by software.
Concept keyboard
Each button in a concept keyboard can be programmed to do a specific task. An overlay is than placed over the buttons to indicate the tasks that they perform.
A mouse
Used to control a cursor on a screen. It allows user to move the cursor around the screen.
Trackball mouse
The user rotates the ball whilst the main body part stays still. It allows students to be more precise. Used in computer aided design (CAD).
Foot mouse
Trackballs have been adapted for those users who have limited hand movement in the form of a foot mouse.
2D scanner
Two-dimensional scanner. By shining light into the surface of the document, the light is reflected and captured onto a light-sensitive device using mirrors and lenses. Than its converted into digital for computer.
Optical character recognition (OCR)
A software, where text on a scanned document is recognised and converted to digital text. But converted document is often full of mistakes.
Optical mark recognition (OMR)
The scanner scans a page and the OMR software note where marks have been made on it. Used to mark multiple choice question papers.
Flatbed scanner
An image is placed on the scanner bed. The scanner moves the light and sensor itself and scans the whole image automatically.
Handheld scanner
The light and sensor must be manually pushed along the image to scan it. Used to scan smaller images.
3D scanner
A 3D scanner will scan a 3D object using a laser or a light source. It will measure and input the geometry of an object into a computer system.
Uses of 3D scanner
Used on the airports. The body is scanned and 3D image is displayed for inspection to check if a person is carrying something.
Biometric devices
Device that recognises human physical characteristics, such as fingerprints. A person’s physical features are scanned and compared if they match with these in the system.
Sensor
A device that records physical inputs.
Analogue
A signal or data that constantly varies.
Digital
A signal or data that consists of two states 1 or 0.
Barcode
Represented by black vertical bars with spaces between them. Can store up to 30 numbers.
Barcode reader
A barcode is scanned and illuminated with a red light an illuminator. A sensor detects the light reflected back. The signal received is an analogue signal. The analogue signal is converted to digital signal, which is then decoded and send to computer as a number.
