Output Devices Flashcards
What is an output device?
Output devices are pieces of computer hardware used to communicate the results of data processing performed by a computer.
What is the objective of output devices?
to turn computer information into a human friendly/readable form.
How do Inkjet printers work?
- Data to be printed is first sent to the printer driver
- Printer driver puts data into a format that the printer can process
- Printer driver checks the status of the printer (e.g. is it out of paper etc.)
- Data is sent to the printer and is stored in a printer buffer
- Sensor checks whether there is any paper in the paper tray
- Sheet of paper is fed into the printer
- When the paper is in the correct position, the print head moves over the page; the 4 ink colours are used in the correct amounts to give required colour
- At the end of each pass, the paper is advanced to allow the next line to be printed
- Printing process continues until the printer buffer is empty
- Once the printer buffer is empty, the printer sends an interrupt to the processor requesting for more data to be sent
- Whole cycle continues until the entire document has been printed
What are Inkjet printers commonly combined with nowadays?
a flatbed scanner to create an all in one solution.
What are some typical applications for Inkjet Printers?
- Low volume printing where speed isn’t critical
- High quality photographic documents
- Home and small office
- Printing on heat sensitive stationary, such as labels
What are some drawbacks of Inkjet Printers?
- Frequent changes of ink cartridges needed for big print run
- Can be rather noisy in operation
- Ink is expensive
What is a Laser Printer?
Laser printers are output devices usually found in businesses and organisations.
What is an Inkjet Printer?
Inkjet printers are output devices usually used in a home or small office for low volume printing.
Why are Laser Printers ideal for high volume printing?
- because they produce very high quality documents at fast speeds.
What do Laser Printers use instead of liquid ink?
a powdered ink/toner cartridge
How do Laser Printers work?
- Data to be printed is first sent to the printer driver
- Printer driver puts data into a format that the printer can process
- Printer driver checks the status of the printer (e.g. is the printer out of toner?)
- Data sent to printer and then stored in a printer buffer
- Printing process starts by giving printer drum a positive charge
- As printer drum rotates a laser beam scans across it removing the positive charge in certain areas; this leaves negatively charged areas which match the text or images to be printed
- Printer drum is coated with positively charged toner; it only sticks to the negatively charged parts of the drum
- Negatively charged sheet of paper is then rolled over the drum
- Toner on the drum now sticks to the paper producing exact copy of the text and images
- To prevent paper sticking to the drum, electric charge is removed once the page has been printed
- Paper goes through a fuser which melts the ink making a permanent copy
- At the very end of the printing process, a discharge lamp removes the electric charge from the drum making it ready for the next page
What are some typical applications for Laser Printers?
- High volume printing where speed is critical
- Shared printer for several users
- Predominantly text based documents
- Found in businesses and offices
What are some benefits of Laser Printers?
- Larger ink cartridges than an inkjet printer
- Cost per page is less than an inkjet
- Generally very quiet in operation
What are some drawbacks of Laser Printers?
Produce particulates and ozone gas which have health issues
- Maintenance can be costly due to fusers or large toner cartridges
- Physically larger than an inkjet printer
What is a 3D Printer?
- 3D printers are output devices used to create three dimensional objects from a 3D computer model.
What can a 3D Printer computer model be created by?
- a 3D scanner, or by hand using CAD modeling software.
What are some typical applications of 3D Printers?
- Home and commercial use
- Prototyping parts and solutions
- Human prosthetics
- Medical aids
What are some benefits of 3D Printers?
- Prototype objects can be created at a fraction of the cost of a factory
- A variety of intricate and “impossible” objects can be printed in a variety of materials
- Computer designs can be shared and printed by others
What are some drawbacks of 3D Printers?
- Expensive to buy although entry models are becoming more affordable
What is a 2D Cutter?
an output device capable of cutting holes or shapes into a flat 2D surface.