Computer science - input and output devices

barcode

a series of dark and light lines of varying thickness used to represent data; the code has to be scanned using laser or LED light source

quick response (QR) code

a matrix of dark and light squares which represent data; the pattern can be read and interpreted using a smartphone camera and QR app

frame QR code

a type of QR code that includes a space for advertising

DAC (digital to analogue converter)

a device that converts digital data into electric currents that can drive motors, actuators and relays, for exmaple

ADC (analogue to digital converter)

a device that converts analogue data (for example, data read from sensors) into a form understood by a computer

charge couple device (CCD)

a light sensitive cell made up of millions of tiny sensors acting as photodiodes

virtual keyboard

an onscreen keybaord which uses the features of the touch screen to emulate a physical keyboard

touch screen

a screen that allows the user to select or manipulate a screen image using the touch of a finger or stylus; touch screens most frequently use capacitive, infra-red or resitive technology

optical mouse

a pointing device that uses a red LED to track the movement of the device and then relays its coordinates to a computer

pointing device

an input deivce that allows the user to control the movement of an onscreen cursor or to allow onscreen selection by clicking a button on the device

computer aided design (CAD)

software used to create drawings

computer tomographic (CT) scanner

technology than can creat ea 3D image of a solid object by slicing up the object into thin layers

capacitive touch screen

a type of touch screen that uses the change in the screen's capacitance (the ability to store an electrical charge) when it is touched by a finger or stylus

infra-red touch screen

a type of touch screen that uses infra-red beams and sensors to detect where the screen has been touched

resisitive touch screen

a type of touch screen that uses two conductive layers which make contact where the screen has been touched

actuator

an output device that converts electrical energy into mehcanical movement

digitala micromirror device (DMD)

a chip that uses millions of tiny mirrors on its surface to create a video display

thermal bubble

inkjet printer technology whereby tiny resistors create heat and form an ink bubble which is ejected onto paper in an inkjet printer

piezoelectric

a crystal located in an ink reservoir within an inkjet printer; the crystal vibrates and forces ink out onto the paper

direct 3D printing

a 3D printing technique in which the print head moves in the x, y and z directions

binder 3D printing

a 3D printing method that uses a two-stage pass; the first stage uses dry powder and second stage uses a binding agent

organic LED (OLED)

a light-emitting diode that uses the movement of electrons between a cathode an anode to produce an on-screen image; it generates its own light so no backlighting is required

loudspeaker

an output device that converts electric current into sound