Printer
Encyclopedia
Printer may refer to:
  • Printer (publishing), a person or a company
  • Printer (computing), a hardware device
  • Optical printer
    Optical printer
    An optical printer is a device consisting of one or more film projectors mechanically linked to a movie camera. It allows filmmakers to re-photograph one or more strips of film...

     for motion picture films
  • The Moscow subway station Pechatniki, whose name means "Printers"


In computers, a printer is a device that accepts text and graphic output from a computer and transfers the information to paper, usually to standard size sheets of paper. Printers are sometimes sold with computers, but more frequently are purchased separately. Printers vary in size, speed, sophistication, and cost. In general, more expensive printers are used for higher-resolution color printing.

Personal computer printers can be distinguished as impact or non-impact printers. Early impact printers worked something like an automatic typewriter, with a key striking an inked impression on paper for each printed character . The dot-matrix printer was a popular low-cost personal computer printer. It's an impact printer that strikes the paper a line at a time. The best-known non-impact printers are the inkjet printer, of which several makes of low-cost color printers are an example, and the laser printer . The inkjet sprays ink from an ink cartridge at very close range to the paper as it rolls by. The laser printer uses a laser beam reflected from a mirror to attract ink (called toner ) to selected paper areas as a sheet rolls over a drum.

The four printer qualities of most interest to most users are:

Color: Color is important for users who need to print pages for presentations or maps and other pages where color is part of the information. Color printers can also be set to print only in black-and-white. Color printers are more expensive to operate since they use two ink cartridges (one color and one black ink) that need to be replaced after a certain number of pages. Users who don't have a specific need for color and who print a lot of pages will find a black-and-white printer cheaper to operate.
Resolution: Printer resolution (the sharpness of text and images on paper) is usually measured in dots per inch ( dpi ). Most inexpensive printers provide sufficient resolution for most purposes at 600 dpi.
Speed: If you do much printing, the speed of the printer becomes important. Inexpensive printers print only about 3 to 6 sheets per minute. Color printing is slower. More expensive printers are much faster.
Memory: Most printers come with a small amount of memory (for example, one megabyte ) that can be expanded by the user. Having more than the minimum amount of memory is helpful and faster when printing out pages with large images or tables with lines around them (which the printer treats as a large image).
Printer I/O Interfaces
The most common I/O interface for printers has been the parallel Centronics interface with a 36- pin plug. In the future, however, new printers and computers are likely to use a serial interface, especially Universal Serial Bus or FireWire with a smaller and less cumbersome plug.
Printer Languages
Printer languages are commands from the computer to the printer to tell the printer how to format the document being printed. These commands manage font size, graphics, compression of data sent to the printer, color, etc. The two most popular printer languages are Postscript and Printer Control Language .

Postscript is a printer language that uses English phrases and programmatic constructions to describe the appearance of a printed page to the printer. This printer language was developed by Adobe in 1985. It introduced new features such as outline font s and vector graphics . Printers now come from the factory with or can be loaded with Postscript support. Postscript is not restricted to printers. It can be used with any device that creates an image using dots such as screen displays, slide recorders, and image setters.

PCL (Printer Command Language) is an escape code language used to send commands to the printer for printing documents. Escape code language is so-called because the escape key begins the command sequence followed by a series of code numbers. Hewlett Packard originally devised PCL for dot matrix and inkjet printers. Since its introduction, it has become an industry standard. Other manufacturers who sell HP clones have copied it. Some of these clones are very good, but there are small differences in the way they print a page compared to real HP printers. In 1984, the original HP Laserjet printer was introduced using PCL. PCL helped change the appearance of low-cost printer documents from poor to exceptional quality.

Fonts
A font is a set of characters of a specific style and size within an overall typeface design. Printers use resident fonts and soft fonts to print documents. Resident fonts are built into the hardware of a printer. They are also called internal fonts or built-in fonts. All printers come with one or more resident fonts. Additional fonts can be added by inserting a font cartridge into the printer or installing soft fonts to the hard drive. Resident fonts cannot be erased unlike soft fonts. Soft fonts are installed onto the hard drive and then sent to the computer's memory when a document is printed that uses the particular soft font. Soft fonts can be purchased in stores or downloaded from the Internet.

There are two types of fonts used by the printer and screen display, bitmap fonts and outline fonts. Bitmap fonts are digital representations of fonts that are not scalable. This means they have a set size or a limited set of sizes. For example, if a document using a bitmap font sized to 24 point is sent to the printer and there is not a bitmap font of that size, the computer will try to guess the right size. This results in the text looking stretched-out or squashed. Jagged edges are also a problem with bitmap fonts. Outline fonts are mathematical descriptions of the font that are sent to the printer. The printer then rasterizes (see raster graphics ) or converts them to the dots that are printed on the paper. Because they are mathematical, they are scalable . This means the size of the font can be changed without losing the sharpness or resolution of the printed text. TrueType and Type 1 fonts are outline fonts. Outline fonts are used with Postscript and PCL printer languages.

See also

  • Nariman Printer
    Nariman Printer
    Nariman Abarbad Printer was an Indian amateur radio operator known for setting up the Congress Radio.With the outbreak of World War II in 1939, the British cancelled the issue of new licences...

     (fl. c. 1940), Indian journalist & activist
  • Casey Printers
    Casey Printers
    Casey J. Printers was a professional American football and Canadian football player. He played college football at Texas Christian University from 1999 to 2001, leading his team to three straight bowl games, before transferring to Florida A&M for his senior year...

    (born 1981), US football player
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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