1.5 Output Devices

Question 1

Output devices

Answer 1

Take data produced by a computer and turn it into a human-readable form

Question 2

Inkjet operating costs

Answer 2

• The inkjet printers are sold at or below production cost
• Ink cartridges are dramatically marked up

Question 3

Laser Printers

Answer 3

• Use dry powdered ink called toner
• Print quality is excellent
• Fast and reliable

Question 4

Dot matrix printers

Answer 4

• Strike an inked ribbon which imprints dots to form letters on the page
• Useful where multi-part stationery is required
• Can work effectively in damp or dirty atmospheres
• Noisy, poor print quality and expensive to buy

Question 5

3D printers

Answer 5

Print 3D objects

Question 6

Applications of 3D printers

Answer 6

• Manufacturing of prosthetic limbs or orthotics
• Reconstructive surgery or general surgery
• Manufacturing parts for cars

Question 7

Dangers of 3D printing

Answer 7

Blueprints of dangerous things could be distributed online

Question 8

RFID (Radio Frequency ID)

Answer 8

• Use a transponder and receiver
• The powered receiver emits radio frequency and energy
• The transponder antenna in the bank card, mobile phone or tag becomes energized by radio waves
• The transponder can then send data to the receiver

Question 9

Uses of RFID tags

Answer 9

• Security control points or identification of people, animals goods or valuables
• Shopping and supply chain traking for goods
• Banking and fast-payment systems
• As a potential replacement for barcode systems

Question 10

Passive Tags

Answer 10

• Passive transponders used in bank cards for example, have no power source themselves and rely on the radio waves from the receiver for their energy

Question 11

Active Tags

Answer 11

• Use a larger, battery powered beacon which can broadcast its own signal to receivers up to 300m away

Question 12

Actuators

Answer 12

Motors that are commonly used in conjunction with sensors to control a mechanism (opening a valve or door, starting a pump, turning a wheel o fan, moving an aircraft aileron)

Question 13

DAC

Answer 13

Digital to analogue converter to convert digital data into analogue signal which is boosted using an amplifier and then sent to a speaker

Question 14

LCD (Liquid Crystal Display)

Answer 14

• Contain groups of red, green and blue diodes to form each pixel
• Require backlighting using Cold Cathode Fluorescent Lamps (CCFL) or LEDs as the crystals act as a light valve and do not emit light themselves

Question 15

LEDs vs CCFLs

Answer 15

• LED reach their maximum brightness almost immediately
• Image is sharper with more realistic and vivid colours
• Produce a brighter and light, which leads to better picture definition
• Since LEDs are very small, this allows the screens to be much thinner in construction
• LEDs last almost indefinitely which makes the screens much more reliable
• LEDs consume very little power and therefore produce very little heat as well and reduce running costs

Question 16

OLED (Organic LED screens)

Answer 16

• Much thinner and lighter than traditional LCD or LED screens
• Plastic, rather than glass also makes them flexible
• Light emitted from OLED is much brighter than LCD or LED

Question 17

Benefits of OLED

Answer 17

• Generate their own light so there is no need for complex backlighting
• Much less power is consumed; good for battery operated devices
• Little heat is produced, reducing fire risk
• Have a larger FOV than LCD screens, and is further enhanced when the screen is curved

Question 18

Multimedia light projectors

Answer 18

• Compact, high-resolution, full-colour projectors
• Can project text, images, video and audio content
• Typically the projector will be ale to input data from a computer, DVD/CD player or storage