Specifications

The Evolution of Printing and Scanning
Technology
When the personal computer was first developed in the late 1970s, many people thought that we’d
see the end of paper in the office. The rise of the PC was accompanied by a rise in the speed, print
quality, and overall performance of printers to help produce outputs of computer data. Thus, as per-
sonal computers enter their third decade, we realize that instead of abolishing paper, computers have
made it easier to produce more and more complex output ranging from the simple reports that were
the major use of the first dot-matrix printers to elaborate brochures and photos that might outlast the
life of the users who print them (let alone their computers!).
We’ve realized since the first PCs were developed in the late 1970s that the capability to produce a
printed version (often called a hard copy) of a document is a primary function of a PC, and that a PC
without access to a printer is only a shadow of the useful tool it can be. Printers and Internet access
have become the two required accessories for the modern computer at home or at work. Whether
connected directly to the computer or accessed via a network, printers are essential. Network access to
printers enables a single high-performance printer to serve many users, and printing can now take
place remotely via the Internet.
But what about the mounds of documents produced before the computer age, or produced in formats
that aren’t PC-friendly? Scanners, once a specialized device found only in the art department of major
companies, have made their way onto corporate and SOHO (small office, home office) desks alike.
Scanners enable printed text and image-based documents alike to be converted into digital form for
printout or storage. Because their use, features, and most common interfaces (parallel or USB) comple-
ment printers, they are also discussed in this chapter.
As you will learn in this chapter, one size cannot fit all when it comes to printers or scanners. With a
wide variety of technologies, features, speeds, intended tasks, and cost, you should be able to find a
printer or scanner that meets your needs—whether you are a corporate buyer looking for a single
device to serve a department, a “road warrior” looking for a portable unit, or a SOHO user looking for
the best bang for the buck. This chapter examines the underlying concepts of all printer and scanner
technologies, the basic types of printers and scanners available today and how they function, and
how to install and troubleshoot a printer or scanner on your PC.
Printer Technology
Three basic types of printer technologies are used with PCs, defined by the method in which the
image is produced on the paper. These three technologies are as follows:
■ Laser. Laser printers function by creating an electrostatic image of an entire page on a photosen-
sitive drum with a laser beam. When an ultrafine colored powder called toner is applied to the
drum, it adheres only to the sensitized areas corresponding to the letters or images on the page.
The drum spins and is pressed against a sheet of paper, transferring the toner to the page and
creating the image. This technology is similar to that used by photocopiers, although differ-
ences do exist in the details of image transfer and in the internal temperatures of the units.
A similar technology is the LED printer pioneered by Okidata and also produced by Lexmark.
These printers replace the laser beam with a fixed array of light-emitting diodes (LEDs) for imag-
ing but are otherwise similar in performance. See the section, “LED Page Printers,” later in this
chapter.
■ Inkjet. Inkjet printers, as their name implies, have tiny nozzles that spray specially formulated
ink onto a page. One method uses heated ink (as used by Canon’s BubbleJet line), and another
method uses piezo-electric print heads (as in Epson’s Stylus and Stylus Color line).