Output devices and printers Flashcards
What does an actuator do?
It carries out physical movements
What are actuators used for?
Opening and closing an automatic door
Turning a wheel
Operating an aircraft’s wing flaps
Why is an actuator needed?
Used with sensors to control many kinds of mechanisms
Translates digital signals into movement of physical objects
What does DLP stand for?
Digital Light Processing projector
How does a DLP projector work?
It is a matrix of millions of micro-mirrors on a small microchip
White light is shone through a rotating colour filter to produce an image
What are DLP projectors used for?
Projecting a computer output onto a wall/whiteboard
What are the advantages of a DLP projector over a LCD projector?
- Higher contrast and definition
- Smoother video quality
- Smaller, lighter and more portable
How does an LCD projector work?
Three mirror filters separate an image into red, blue and green wavelengths
The three images are then combined to produce one full-colour image
What is an LCD projector used for?
Projecting a computer output onto a wall/whiteboard
What are the advantages of an LCD projector over a DLP projector
- Cheaper
- Quieter
- Less power and heat output
How does an inkjet printer work?
Tiny droplets of ink are forced through a fine nozzle onto a sheet of paper
What is an inkjet printer used for?
Small-scale print jobs
High-quality professional photos
What are the advantages of an inkjet printer?
They are small and compact
They are excellent for high-quality colour photos
What is a disadvantage of an inkjet printer?
Paper can be damp/wrinkle after printing
How does a laser printer work?
- The printer generates a mirror image of the printed page and draws the image onto a drum using a laser (creates negative charged areas)
- Toner (powdered, positively electrostatic ink) is attracted to the drum
- The toner is transferred to the paper and bonded using a heat roller
