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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If you get a memory overflow error, try reducing the resolution, printing smaller graphics, or. In most laser printers, these gear systems are packed together in discrete units generically called gear packs or gearboxes. Then look for printers that have the same resolution but different ppm rates.

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

First, the CPU processes your request and sends a print job to an area of memory called the print spooler. The physical cleaning mechanism either deposits the residual toner in a debris cavity or recycles it by returning it to the toner supply in the toner cartridge.

Cleaning The printing process ends with the physical and electrical cleaning of the photosensitive drum see Figure The entire surface of the compgia has a uniform negative charge of gri and volts following its charging by the primary corona wire or charge roller.

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. The printer must also be electrically cleaned. The maximum number of pixels determines how well you can capture an image and gdu the image will look when scaled up in size.

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

Solid ink printers use solid sticks of non-toxic “ink” that produce more vibrant color than other print methods. To reduce maintenance costs, however, many other laser printer parts, especially those that suffer the most wear and tear, have been incorporated into the toner ccomptia.

Do not assume that every error with the word memory in it can be fixed simply by adding more RAM to the printer. Xerox’s base model starts at about twice the cost of a laser printer, with the expensive model selling for about six times the cost! Printers are designed to accept predefined printer languages that handle both characters and graphics.

The first is the direct thermal printer, and the other is the thermal wax transfer printer. Thermal wax printers work similarly to dye-sublimation printers, except that instead of using rolls of dye-embedded film, the film is coated with colored wax. RET enables the printer to insert smaller dots among the characters, smoothing out the jagged curves that are typical of printers that do not use RET see Figure Exposing A laser is used to create a positive image on the surface of the drum.


The BIOS for the printer either built into the printer or a printer driver interprets the raster image in the same way a monitor does, “painting” the image as individual dots. A printhead containing thousands of heating elements, capable of precise temperature control, moves across the film, vaporizing the dyes and causing them to soak into specially coated paper underneath before cooling and reverting to a solid form.

The inks have improved over the years, too, now delivering better quality and longevity than ever. You can use a scanner to make digital copies of existing paper photos, documents, drawings, and more. Another feature of inkjet printers is that they can support a staggering array of print media. As you might imagine, the higher resolution images capture more fine detail.

Developing 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 printing process ends with the physical and electrical cleaning of the photosensitive drum see Figure Printers that create an image on paper by physically striking an ink ribbon against the paper’s surface are known as impact printers.

Charging Now we turn to the physical side of the printing process.

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. 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. These five companies make most of the printers on the market today.

Every particle on the drum hit by the laser releases most of its negative charge into the drum. Many people simply still prefer dealing with a hard copy, even as portable devices have proliferated. Sensors and Switches Every laser printer has a gdk number of sensors and switches spread throughout the machine. Cloud and Compgia Printing Blurring the line between traditional and virtual printing, a variety of applications, such as Google Cloud Print, will install a virtual printer on your system that wraps up your document and sends it out over the Internet or other network to a cloud server, which eventually ends up routing it to a real printer for printing all without needing to have a driver installed for it.

The seven steps to the laser printing process may be performed in a different order, depending on the printer, but it usually goes like this:. Although daisy-wheel printers essentially an electric typewriter attached to the computer instead of directly to a keyboard have largely disappeared, their cousins, dot-matrix printers, still soldier on in many offices.


Scanners differ a lot in grayscale depth, a number that defines how many shades of gray the scanner can save per pixel. This is another mechanical function with a dedicated duplexing assembly for reversing the paper. If it does, you may be able to plug your printer into a USB port on the router.

When particles are comptai by the laser, they are discharged and left with a volt negative charge. Printer speed is a key determinant of a printer’s price, and this is an easy assertion to prove, so Try This! All flatbed scanners, the most common variety of scanner, work the same way.

Figure shows an open scanner. An inkjet printer also has a RIP, but it’s part of the software driver instead of onboard hardware circuitry. Any electrical charge present in the particles bleeds away into the grounded drum, leaving the surface particles electrically neutral. We’ll revisit printing in Windows in more detail later in this chapter.

Although this makes replacement of individual parts nearly impossible, it greatly reduces the need for replacement; those parts that are most likely to break are replaced every time you replace the toner cartridge. All of these mechanical features can wear out or break and require service or replacement. When you push the front button on the Epson Perfection scanner in Figurefor example, the Epson software opens ready to start scanning.

First, the paper must be grabbed by the pickup roller and passed over the separation pad, which uses friction to separate a single sheet from any others that were picked up.

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 ccomptia with other components in a multifunction device.

You can and will adjust the first three during the scanning process, although probably only down from their maximum. Solid Ink Printers Solid ink printers use just what you’d expect solid inks. Any particle on the drum struck by the laser becomes conductive and its charge is drained away into the grounded core of the drum.

Photoconductive means that particles of these compounds, when exposed to light that’s the “photo” partwill conduct electricity.