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Digital Imaging Tutorial - Delivery
6D. Technical
Infrastructure:
DELIVERY
Key Concepts
introduction
networks
concerns
speed
trends
monitors
evaluation
image quality
printers
technologies
evaluation
P
RINTERS
As long as computers are bulky, display devices low resolution and hard on
the eyes, battery technology in its infancy, and the communications
infrastructure bound by cables, the desire to create printouts from digital
images will endure. However, the costs of actually making high-resolution
images available online, in formats that can be printed via a number of
platforms and a range of printers, should not be underestimated. Before
making promises to deliver print-quality images in a networked environment,
verify that the technical infrastructure is up to the task, and consider the
additional storage costs associated with online access.
P
RINTER
T
ECHNOLOGIES
Today, black and white printing is dominated by two technologies: Inkjet
printers, which squirt liquid ink through tiny nozzles onto the paper, and laser
printers, which use a light source to create charges on a photoconductive
drum, allowing it to attract dry ink particles (toner) that fuse onto paper. Inkjet
printers have become quite inexpensive, but are slower than lasers and
generally not designed for high volume printing. High end production laser
printers can produce well over 100 pages per minute at 600 dpi.
Both technologies have been adopted for color. Color inkjet printers come in 3-
and 4-color models. Color lasers are much more expensive, both for initial
purchase and for the cost of consumables. Color inkjets and lasers are both
substantially slower than their black and white counterparts, color inkjets
average about 5 pages per minute for text and 1 page per minute for full page
graphics. Color lasers are faster, averaging 12 pages per minute for text, and
2 pages per minute for full page graphics.
Several other technologies are available for color printing. These include dye
sublimation, solid ink, and thermal wax. Dye sublimation is especially
significant in that it can produce true continuous tone color printouts, though it
is extremely slow and requires special coated paper.
For larger scale color printing, Electronics for Imaging makes the Fiery line of
print servers, which enable digital color photocopiers and digital presses to be
networked to serve as high volume, high quality color printers. The resulting
combination is called a copier-printer. Resolution is generally 400 dpi
maximum, but is supported for whatever paper sizes the copier normally
uses.
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