Computer Science 2210 - Input and Output Devices

Input Device

A hardware device that converts external data into a form the computer can understand, such as keyboards, touchscreens, and microphones.

Ergonomic Keyboard

A specially designed keyboard that prevents injuries from frequent typing by offering extra support to the wrists and hands.

Repetitive Strain Injury

An injury to the wrists or hands caused by frequent and prolonged use of a keyboard.

Speech Recognition

A technology using a microphone to input spoken words, which are recognized and displayed on a screen, entered into a word processor, or used in other applications.

Voice Recognition

A system where a user's voice is detected by a microphone and converted into digital data, creating a digital wave pattern from spoken words.

Capacitive Touchscreen

A touchscreen composed of layers of glass acting like a capacitor; it offers good visibility, multi-touch support, and high durability, but only functions with bare fingers.

Infrared Touchscreen

A glass touchscreen system using either heat-sensitive technology or an array of optical sensors; it supports multi-touch and high durability but is relatively expensive.

Resistive Touchscreen

A touchscreen technology featuring a top polyester layer and a bottom glass layer; it is inexpensive and operable with bare fingers, gloved fingers, or a stylus, but lacks multi-touch and has poor visibility in bright sunlight.

Sensor

An input device that reads or measures physical properties of its environment, such as temperature, pressure, or acidity.

Analogue to Digital Converter (ADC)

A device that converts continuous physical or analogue measurements from sensors into discrete digital values for computer processing.

Temperature Sensor

A sensor used to control central heating systems, monitor/control chemical processes, or manage greenhouse temperatures.

Moisture / Humidity Sensor

A sensor used to measure and control soil moisture levels or air humidity levels inside a greenhouse.

Light Sensor

A sensor used to control street lighting, adjust greenhouse light levels, or automatically switch on car headlights in the dark.

Infra-red / Motion Sensor

A sensor used to trigger automatic windscreen wipers, detect intruders in alarm systems, or count people entering and leaving a building.

Pressure Sensor

A sensor used to detect intruders by weight, weigh vehicles, or control industrial processes where gas pressure is critical.

Acoustic / Sound Sensor

A sensor designed to detect noise levels such as footsteps in burglar alarms or liquid dripping inside pipes.

Gas Sensor

A sensor used to monitor pollution levels in rivers or air, and measure $O_2$ and $CO_2$ levels in a greenhouse.

pH Sensor

A sensor used to monitor soil acidity levels in greenhouses or track environmental pollution in rivers.

Magnetic Field Sensor

A sensor used in anti-lock braking systems (ABS) on motor vehicles and in devices requiring detection of magnetic field changes, such as mobile phones and CD players.

Monitoring System Process

A system workflow where sensors send data through an ADC to a microprocessor, which checks readings against stored values and triggers warnings or alarms if data is out of range, without directly altering the process.

Control System

A system where sensor data converted via ADC is evaluated against stored values, and the microprocessor actively outputs signals to control valves, motors, or heaters to directly affect future sensor inputs.

Anti-Lock Braking Systems (ABS)

A safety feature in motor vehicles that uses magnetic field sensors to prevent the wheels from locking up when brakes are applied sharply.

Interactive Whiteboard

An input/display device that projects computer images onto a board using a digital projector and allows users to write on the surface, saving inputs electronically.

2D Scanner Operation

The process where a document on a glass plate is illuminated by a bright xenon lamp, scanned by a moving scan head, focused through lenses onto a Charge Coupled Device (CCD), and converted into digital image data.

Charge Coupled Device (CCD)

A component in a scanner made of integrated circuits on silicon containing thousands of light-sensitive pixels that convert light into electric charges to form an electronic image.

3D Scanner

A scanning device that scans physical solid objects in three dimensions to produce a 3D digital model for use in Computer Aided Design (CAD).

Barcode

A series of dark and light parallel lines of varying thickness representing numbers from $0$ to $9$, used for stock control and rapid checkout processing.

QR Code

A matrix pattern of dark squares on a light background capable of storing over $7000$ digits, including website URLs or promotional links.

Digital Camera

An input device that captures digital photos, using an internal microprocessor to adjust shutter speed, focus, flash, aperture, image size, and red-eye reduction.

Output Device

A hardware component that presents the results of computer processing in a human-understandable form, such as monitors, printers, speakers, or actuators.

Inkjet Printer

A printer that creates hardcopies by spraying ink droplets onto paper using thermal bubble or piezoelectric technology; ideal for low-volume or single colour photo prints.

Laser Printer

A high-speed printer that utilizes dry powder ink and static electricity to produce high-volume, high-quality monochrome or colour documents.

Direct 3D Printing

A 3D printing technique using inkjet technology where the print head moves left to right to build solid objects layer by layer.

Binder 3D Printing

A 3D printing method similar to direct 3D printing that uses two passes per layer to bind material together into a solid structure.

Actuator

An electromechanical output device used in control applications to create physical motion or operation based on signals from a computer.

Digital to Analogue Converter (DAC)

A device that converts digital data from a computer into analogue voltages to drive devices like loudspeakers or actuators.

Sampling Rate

The rate at which a Digital to Analogue Converter (DAC) translates digital output values into analogue voltages.

Liquid Crystal Display (LCD)

A display screen whose front layer consists of liquid crystal diodes grouped in threes or fours (pixels) that require a backlight to produce an image.

Cold Cathode Fluorescent Lamp (CCFL)

An older LCD backlighting technology using two fluorescent tubes behind the screen, which produces a slightly yellowish tint and requires warming up.

LED Monitor

A flat screen display using Light Emitting Diodes as a backlight, providing whiter light, higher brightness, lower power consumption, and longer lifespan than