What You See
Is What You Get.
has been fondly referred to as WYSIWYG (pronounced “ wyziwig”) among professionals
and ordinary users. The phrase, or the term “wysiwig” probably best simplifies
the close association between the two most popular and most commonly used
output devices: the monitor and the printer.
While monitors provide users temporary “soft copies” of results, printers
provide people with permanent and tangible “hard copies” of processing
results. Printers produce hard copy results such as letters, management
reports, and program listings. Printer output can come in form of words,
number, and graphics very much like the monitor. Before and even during
the printing process, output is usually viewed by the user on the monitor.
Printers are classified according to the means by which images are transferred
on paper. Hence, printers are of the impact and non-impact type.
Impact printers. To transfer image on paper, impact printers use mechanical
pressure very much like the typewriter. Images are transferred on paper
by physically striking the ribbon against the paper by a print hammer.
This mechanical action produces a controlled impact enough to transfer
image from the hammer, to the ribbon, and finally to the paper.
Impact printers rely on dot-matrix and daisy-wheel technology.
Non-Impact Printers. Non-impact printers are growing in popularity because
of higher quality results and faster output (about 10 times) than impact
printers. They also perform quietly because they contain fewer moving parts
and do not use hammers or pins found in impact printers. Non-impact printers
also offer the advantage of having typefaces (letter designs) changed automatically.
Dot-matrix printers are the least expensive and most
commonly used type of printer. The printer arranges dots to form characters
and images. The hammers, or pins (contained in a box called printhead)
are activated to form images with dots as the printhead moves horizontally
across the paper.
Daisy-wheel printers are known for their high-quality
printing and are popular among professionals who use it for word processing
and correspondence. The daisy-wheel printer consists of a replaceable wheel
with sets of spokes. Each spoke contains a raised character very much like
the typewriter. In fact, some electronic typewriters use the daisy-wheel
Non-impact printers use ink-jet or laser technology. While you may not
have the opportunity to use non-impact printers in your laboratory class,
it is worth getting familiar with this type of printers because they are
continually getting cheaper and more popular.
Ink-Jet Printers. Ink-jet printers contain jet
nozzles that spray electrically charged ink through an electric field,
which deflects the ink to produce a dot-matrix character or image. Many
models of ink-jet printers are capable of printing in color.
Laser Printers. Utilizing the technology of xenographic
copy machines, laser printers are becoming popular because of it’s high
quality output and it’s continually decreasing cost. Just like the copying
machines you are familiar with, laser printers contain a light scan, drum,
and toner that are used to transfer an image into a sheet of paper. Laser
printers are capable of printing outputs with resolutions of 300 dots per
inch to 600 dpi. The higher the resolution, the better the quality of printed
image. Typically, today’s laser printers can print up to 8 sheets per minute
and can produce documents that combine text and graphics on the same page.