CompTIA A+ Certification Exam Objectives .. GDI graphics device interface. GHz gigahertz. GUI graphical user interface. GPS. The Windows GDI builds the page and then sends it to the printer. A less- sophisticated method of communicating to a printer is to use the GDI (Graphics Device. GDI is actually a Windows component and is not specific to printers. Instead, it’s a series of components that govern how images are presented to both monitors.

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At this point, the drivers and other software controlling the scanner pop up, providing an interface with the scanner as shown in Figure These five companies make most of the printers on the market today.

Most printers, scanners, and multifunction devices connect to a computer via a USB port, but Wi-Fi or Ethernet network connections are also very popular.

CompTIA A+ Certification Exam Guide, A+ Chapter 27 Printers and Multifunction Devices (1)

Because multifunction devices are so varied, we’ll take a look at some of the individual components and technologies you may find inside them separately be prepared to encounter these components as both standalone devices and included with other components in a multifunction device. Erase Lamp The erase lamp exposes the entire surface of the ocmptia drum to light, making the photosensitive coating conductive. You place a photo or other object face down on the glass called the platenclose the lid, and then.

Exposing A laser is used to create a positive image on the surface of the drum. Charging Now we turn to the physical side of the printing process. That won’t make for very good scans!

Do not assume that every error with the word memory in it can be fixed simply by adding more RAM to the printer. With binary numbers, each extra bit copmtia information doubts the color detail in the scan.

Connectivity Most printers, scanners, and multifunction devices connect to a computer via a USB port, but Wi-Fi or Ethernet network connections are also very popular.

All of these mechanical features can wear out or break and require comltia or replacement. Because a laser printer has to paint the entire surface of the photosensitive drum before it can begin to transfer the image to paper, it processes the image one page at a time. The color cartridge had separate compartments for cyan bluemagenta redand yellow ink, to print colors by using a method known as CMYK you’ll read more about CMYK later in this chapter.


The entire surface of the drum has a uniform negative charge of between and volts following its charging by the primary corona wire or charge roller. When particles are struck by the laser, they are discharged and left with a. Thermal wax printers work similarly to dye-sublimation gdii, except that instead of using rolls of dye-embedded film, the film is coated with colored wax. At first these devices weren’t terribly great at any of their functions, but today’s mature multifunction devices are more common than their single-function counterparts.

The enhanced resolution numbers are useless. Following are the more common printer languages. After the cleaning process, the drum should be completely free of toner and have a neutral charge. All flatbed scanners, the most common variety of scanner, dgi the same way. We’ll revisit printing in Windows in more detail later in this chapter. It’s quite a disappointment to come home with your new printer only to find you can’t connect it because it didn’t come with a USB cable.

Resolution is most important when you’re printing complex images such as full-color photos, or when you’re printing for duplication and you care that your printouts com;tia good. As in most such software, you choose File I Create and then select Scanner.

Printer speed is a key determinant of a printer’s price, gd this is cmptia easy assertion comptla prove, so Try This! The scanner runs a bright light along the length of the platen once or more to capture the image.

Most inkjet printers use heat to move the ink, while a few use a mechanical method. The RIP takes the digital information about fonts and graphics and converts it to a rasterized image made up of dots that can then be printed.

CompTIA A+ Certification Exam Guide, A+ Chapter 27 Print

If they did not, the PRT scR print screen key would not work with every printer. Just be sure to unlock before you try to use it or you’ll get a light that’s stuck in one position. Take a look back at Chapters 20 and A laser printer must have enough memory to process an entire page.

Finally, a static charge eliminator removes the paper’s positive charge see Figure The first laser printers created only monochrome images; you can also buy a color laser printer, but most laser printers produced today are still monochrome. Any particle on the drum struck by the laser becomes conductive and its charge is drained away into the grounded core of the drum.


Now we turn to the physical side of the printing process. Printer Languages Now that you’ve learned about the different types of print devices and techniques, it’s time to take a look at how they communicate with the computer. Want to learn a language? Better scanners give you the option of copying directly from a photographic negative or slide, providing images of stunning visual quality assuming the original photo was halfway decent, of course!

This gives you a total of 16, color variations in the scanned image, which explains why some scanners refer to this as “millions of colors” in their settings.

As you might imagine, the higher resolution images capture more fine detail. Next, Windows sends the first print job to the comptiaa. Although a color laser printer can produce complex full-color images such as photographs,they really shine for printing what’s known as spot color for example, eye-catching headings, lines, charts, or other graphical elements that dress up an otherwise plain printed presentation.

Those particles with a lesser negative charge are positively charged relative to the toner particles and attract them, creating a developed image see Figure The scan gdk relates to all four of the other variables, and the maximum speed is hard-coded into the scanner. In addition to the basic CMYK inks, compgia additional cartridges provide for green, blue, gray, light cyan, dark cyan, and more. Support in other operating systems varies, but most of them have third-party software available for working with XPS files.

Many of these sensors are really tiny switches that detect open doors and so on. This not only was more cost-effective for the user, but co,ptia also resulted in higher quality printouts. CompTIA wants you to know specifically about a few of these options, so we’ll discuss them in a little more depth.