Unit 1 computer users task Think over the following questions and give your answers
Task 6. Read and translate the following text
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| Task 6. Read and translate the following text:
TEXT B. Types of Printers Printing information on paper is still the most common form of output. It is frequently required for legal documentation. Thus, computers can produce reports, correspondence, sales invoices, payroll checks, bank statements and others. A printer is a peripheral device with small liquid crystal display which produces a hard copy of documents stored in electronic form. Many printers are primarily used as local peripherals and are attached to a computer by USB cable. Some printers, commonly known as network printers, have built-in network interface (wireless or Ethernet) and can serve as a hardcopy device for any user on the network. Individual printers are often designed to support both local and network connected users simultaneously. Some printers combined with scanners and fax machines in a single unit can function as photocopiers. Printers that include non-printing features are sometimes called Multifunction Printers (MFP), Multifunction Devices (MFD) or All-In-One (AIO) printers. Most MFPs include such features as printing, scanning and copying. The choice of print engine has a substantial effect on what jobs a printer is suitable for because different technologies have different levels of image/text quality, print speed and noise. In addition, some technologies are inappropriate for certain types of physical media such as carbon paper or transparencies. Printers can be classified by the print technology they employ. The term dot-matrix printer is applied to impact printers that use a matrix of small pins to create precise dots. The advantage of dot-matrix over other impact printers is that they can produce graphical images in addition to the text. Dot-matrix printers were one of the most common types of printers applied for general use (for home and small office). Such printers would have either 9 or 24 pins on the print head. Ink-jet printers spray very small droplets of ink which have electrical charge onto the paper. The placement of the ink is determined by the charge of a cathode and electrode between which the ink moves. Solid ink is a technology used in computer printers and multifunction devices originally created by Tektronix in 1986. Solid ink-jet printers are the most commonly used as colour office printers. Drawbacks of this technology include high power consumption and long warm-up time. The most famous manufacturers of ink-jet printers are Canon, Hewlett-Packard, Epson and Lexmark. Laser printers use an electrostatic process similar to a photocopying machine to produce many pages per minute of high-quality black-and-white output. Laser printers are very fast and can use different sizes of paper. Since they are non-impact printers they are very quiet and produce good graphics. The laser printer works by beaming a laser onto an electrically charged drum which creates an invisible image on the drum, revealed when a special substance, called toner, is poured over it. When the paper is brought into contact with the drum, the image melts onto the paper as it is heated. Laser printers have many significant advantages over other types of printers. Unlike impact printers, the speed of laser printers can vary and depend on many factors, including the graphics intensity. The fastest monochrome laser printers can produce over 200 pages per minute (ppm) while the colour ones can print over 100 ppm. A plotter is a vector graphics printing device used to print graphical plots. There are two types of plotters: pen and electrostatic plotters. Pen plotters print by moving a pen across the surface of paper to draw complex line art and text. When computer memory was very expensive and processor power was very low, it was the fastest way of producing colour high-resolution vector-based artwork or very large drawings efficiently. Thermal printers produce printed images by heating paper selectively when it passes over the thermal print head. The coating becomes black in the areas where it is heated. Two-colour thermal printers are capable of printing both black and an additional colour (often red), by applying heat at two different temperatures. Inkless printers use paper with colourless dye crystals embedded between the two external layers of the paper. When the printer is turned on, the heat of the drum causes the crystals to colorize at different rates and become visible. The inkless printing technology, Zink, originally developed at Polaroid, became available in 2007. Because of the way it prints, the printer can be as small as a business card and the produced images are waterproof. Nowadays, Xerox works on an inkless printer which uses a special reusable paper but this technology is still in development. A dye-sublimation printer (or dye-sub printer) employs the process of dye transferring to media, such as a plastic card, paper or canvas. These printers are primarily intended for high-quality colour applications, including colour photos, and they are less suited for text. This type of printers is now increasingly used as a dedicated consumer photo printer. Download 0.54 Mb. Share with your friends:
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