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.
QR codes
A quick response code is a 2D square barcode. QR codes are two-dimensional and store data both horizontally and vertically. Can store about 7000 numbers. Useful for creating links and storing things.
Encoding
The process of converting data or information to a particular form.
Digital camera
Capture an image by recording the image via a sensor called a charge-coupled device (CCD). The image is stored and can be viewed on the screen.
Touch screen
Interactive device that combines a liquid crystal display (LCD) with touch-sensitive sensors. The sensors recognise simple touches. The screen determines which part of the screen has been touched.
Capacitive touchscreen
Uses a natural electrical signals that we have in our bodies to detect when we are touching the screen.
Resistive touchscreen
Has multiple layers with space in between. When slight pressure is applied to the screen the layers touch and the device recognises that we are touching the screen.
Interactive whiteboard
The computer’s visual display is projected onto the board. The board is then calibrated to make sure that sensors line up with the displayed image. The sensors determine which part of board has been touched.
Microphone
Is an analogue input device that records sound. The analogue sound must be converted into digital format before the computer can process it.
Analogue-to-digital convertor (ADC)
A device that converts analogue data into digital data.
Speech-to-text software
Allows the user to speak words which the computer converts to text in a document. Ideal for disabled people.
