Section 12.2
Peripherals
12.2 Output Devices
12.2.1 Impact Printers
Daisywheel Printers
The printing characters are mebossed on a spherical head.
the head is rotated so that the desired character is foremost when
the heads strikes the paper through the ribbon.
Line Printers (often used with mainframes)
Line printers print off one line at a time. However this is not
quite true.
A drum with rows of the same letter embossed upon it rotates at
high speed. All the As are printed for a given line, then the Bs,
etc.
This is done by hammers that strike the paper on the other side
to the embossed characters.
12.2.2 Ink Jet Printers
Ink jet printers work bydirecting a fine jet of ink at the paper.
Advantages:
- Low set up cost
- Quiet
- Good print resolution
- Full colour capacity
Disadvantages:
- Slow print speed
- Printing consumables can be expensive
- Large areas of colour can warp the paper
12.2.3 Laser Printers
Laser printers fuse powdered ink/toner onto the paper by heat and
pressure.
Advantages:
- Very high quality output
- Typically they are fairly fast
- Quiet
Disadvantages:
- Budget and mid-range models are available in monochrome
- Running costs are higher than those of impacts printers
12.2.4 Plotters
Plotters are used to produce high quality line drawings.
Most plotters are vector plotters. They move a pen using point to
point data.
Colour vector plotters have a rack with several pens.
Advantages:
- Can handle large paper sizes
- Ink pens are relatively inexpensive
Disadvantages
- Detailed diagrams can be slow to print
- The line thickness may be too great for some applications
