Xilinx at Work Printer Glossary

Printer Glossary

This glossary defines important concepts, terms, and abbreviations related to printers. Please use your browser's "Find" function to locate the desired information.

A thru H	Definition of Terms
Adobe PostScript	A page description language (PDL) developed by Adobe Systems Incorporated, and used on many high-end printers.
Adobe Type Manager	(ATM); a font management and rasterization program which converts Adobe Type 1 and Type 3 fonts to bitmaps for printing or display on a computer screen. ATM is available as a program to run in the Windows environment to allow the display of PostScript fonts by Windows programs, and is built-in to some other graphical user interfaces.
Bitmap	An array of dots, normally containing an image formed by a pattern of "white" dots and "black" dots.
Bitmap Font	A font in which each character is stored as an array of dots, the pattern of which forms a letter or symbol.
Bitmap Graphic	An array of dots, in which the pattern of the dots forms a picture or other non-text item such as a line.
Bubble Jet	Canon's trade name for its thermal drop on demand ink jet printer technology. The ink is heated, producing a bubble that expands and ejects the ink out of the nozzle. As the bubble cools, the vacuum created draws fresh ink back into the nozzle.
Built-in Font	See resident font.
Cartridge	May refer to ROM cartridge, font cartridge, emulation cartridge, toner cartridge, toner/developer cartridge or print cartridge.
Centronics Interface	This 36-pin connection was designed by Centronics Corporation and has become the preferred way to attach most printers to a PC parallel data port.
Character Attributes	A misnomer for typestyle, commonly used to refer to bold, italic, underline and other typestyle qualifiers used with a typeface.
Charged Roller	A roller in a laser printer which imparts an electrostatic charge to another surface. Charged rollers are used in some small printers in place of corotrons to reduce ozone emissions.
CMYK	The Cyan Magenta Yellow Black model for standards in color ink jet printing. These are the four basic process colors used in conventional color printing. By overlaying or dithering combinations of these four inks in different proportions, a vast range of colors can be created.
Composite Black	The creation of black from cyan, magenta and yellow inks. Mixing inks is not a perfect operation, and composite black is often muddy. This is why the CMYK model is used in professional printing. See also True Black.
Contour Font	An alternative term for an outline font.
Controller	Normally an abbreviation of printer controller, the dedicated computer in a printer which creates the image to be printed.
Corotron	A wire in the printer mechanism which carries a very high voltage to generate an electrostatic charge on a nearby surface, such as photoreceptor or sheet of paper. There are several corotrons in most printers. The high voltage in corotrons ionizes the air surrounding the corotron and generates ozone gas as a by-product.
Developer	The mechanism and magnetic powder used to transfer toner from the toner hopper onto the photoreceptor.
Diffuse Dither	A method for printing continuous-tone images on laser printers in which the grayscale information is represented by randomly located printer dots. Diffuse dithers do not photocopy well because of the small, random, dot location in the image.
Dithering	A halftoning method where several dots of the primary colors are printed in various patterns to give the impression of a larger color spectrum.
Dot	A single point written by a laser, or a single point in a bitmap.
Dot Matrix	A type of printer, also known as serial dot matrix, that uses one or two columns of dot hammers to form images out of dots. The more dot hammers used, the higher the resolution of the printed image.
Downloaded Font	A font which is stored in a computer, and sent to the printer via the communications interface when required, to be stored in the printer. Normally downloaded fonts are held in RAM on the printer, and are lost when the printer is switched off. Some printers are able to hold downloaded fonts on hard disk to prevent loss when the printer is switched off.
DPI	Dots Per Inch: a unit of measure used to describe the resolution of images produced by printers or other output devices. The printed dots from a 600 dpi printer are far smaller than the dots created by a 300 dpi printer. As a result, the output is smoother and more detailed, while dithering patterns will deliver more realistic colors.
Drum	A common term for a cylindrical photoreceptor.
Dye-Sublimation	A specialist print technology used for demanding graphic arts and photographic applications that require continuous tone output.
Edge Enhancement	A generic term for the edge-smoothing technique which reduce the jagged appearance of angled lines on laser printers, as used in HP's Resolution Enhancement Technology, and copied by many other printer manufacturers.
Emulation	A generic term for a printer language. Most printers mimic or "emulate" the behavior of the market-leading models of printer by copying their printer language.
Energy Star	Dept. of Energy low power product classification typically used for appliance and office equipment.
Engine	Normally an abbreviation of printer engine, the mechanism which "writes" a bitmap onto paper.
Escape Code	A special control character used by computers and printers, character number 27 decimal, 1B hexa-decimal in the standard ASCII character set.
Escape Code Language	A printer language in which each command is preceded by a special character, normally the escape code, to signify that what follows is a command rather than data.
Escape Sequence	A sequence of characters which form a command to be obeyed by the printer, preceded by the escape code and ended with a termination character.
Face-Down	Refers to an output tray on a printer in which pages are delivered with the readable side facing down. As each sheet is placed on top of the last, multi-page documents delivered to a face-down tray are normally in the correct page order.
Face-Up	Refers to an output tray on a printer in which pages are delivered with the readable side upwards. As each sheet is placed on top of the last, multi-page documents delivered to a face-up tray are normally in reverse page order.
Feathering	A term used when describing printed text quality. Feathering occurs when deposited ink follows the contours of the paper. Depending on the viscosity of the ink, the rougher the grain of the paper the more pronounced the feathering will be.
First print out time	The time taken between a printer receiving the data for the first page of a print job, and delivering the page to the output tray. Most printers do not start printing immediately the data is received, but need a few seconds in which to assimilate the data, setup the page formatting, and start the motors which drive the paper path.
Font	A collection of characters in a particular typeface, typestyle, and character set. A bitmap font is normally also defined by size and orientation.
Font Cache	An area of RAM in a printer which is used for the temporary storage of bitmap fonts which have either been read from hard disk, or created from outline fonts.
Fuser	The mechanism in a laser printer which binds the toner to the paper. Most fusers use hot rollers and fuse the toner into the paper using heat and pressure, but a few printers have radiant fusers which fuse using heat alone.
Fuser Oil	A temperature resistant oil used on fuser rollers to prevent toner adhering to the surface of the rollers. On small printers the fuser oil is normally contained in the fuser cleaning pad.
GDI	Graphical Device Interface: the native graphical language of Windows. A GDI-compliant printer will print exactly what is displayed on a Windows screen without having to transpose it into a printer language. All the processing happens on the PC. This helps reduce the price of the printer, since image processing circuitry isn't needed.
Gray Scale	Technique where shades of gray are synthesized using patterns of black and white dots.
Halftone	Different-sized black dots produced by turning particular dots on and off during printing, either on a laser printer, an image setter, or a printing press. The dots repeat in a regular pattern, creating the illusion of continuous tone. Color ink jets use their process colors in a similar scheme. Other colors are produced by laying down patterns of the process color dots, varying the pattern and ratio of each color. Halftone dots are not the same as printer dots.
HPGL	Hewlett-Packard Graphics Language, a vector graphics language used by Hewlett-Packard plotters and commonly output by CAD software. Some laser printers emulate HPGL to allow their use with CAD packages.
HP PCL	Hewlett-Packard Printer Control Language. The most popular and widely emulated Escape Code printer language. PCL is available in several variants including PCL 3 , 4, 5 and 6, each of which provides more facilities than the previous variant.
I thru P
Ink Jet Printer	A printer technology where ink is splashed onto the printer paper to form an image or character.
Laser Printer	A type of printer that utilizes a laser beam to produce an image on a drum. The light of the laser alters the electrical charge on the drum wherever it hits. The drum is then rolled through a reservoir of toner, which is picked up by the charged portions of the drum. Finally, the toner is transferred to the paper through a combination of heat and pressure. This is also the way copy machines work.
LCD Printer	Similar to a laser printer. Instead of using a laser to create an image on the drum, however, it shines a light through a liquid crystal panel. Individual pixels in the panel either let the light pass or block the light, thereby creating a dot image on the drum.
LED Printer	An electrophotographic printer that uses a matrix of LEDs as its light source. The LED mechanism is much simpler than its laser printer counterpart. A stationary array of LEDs is used instead of numerous moving parts, and the LEDs are selectively beamed onto the drum.
Media	Anything which a laser printer can print on, e.g. paper, card, transparencies and labels.
Memory	Data storage space, typically RAM. The larger the amount of memory in a printer, the more data the printer can hold, and hence (generally) the more complex the pages it can produce.
MFP	Multifunction Peripheral. Today, this means the class of devices that scan, copy, print and FAX.
Network Printer	A printer which is designed to connect to a network and be used by groups of users, a sub-class of workgroup printers.
Office Printer	A printer which is designed for general purpose office use, and may be used by an individual user, or shared by a small group of users.
Outline Font	A font in which each character is represented by sets of equations or vectors which define the outline of the character. An outline font cannot be printed "as is", but must first be scaled to the appropriate size, and "filled" with dots to make a bitmap. As outline fonts can be scaled they may be used to create characters of any size, and may be rotated to any angle.
Parallel Interface	A communication mechanism used to transfer data from a computer to a printer, several bits at a time. Most parallel interfaces are 8 bits wide, and thus transfer one byte in each transaction, however a few are 16 bits wide, transferring two bytes simultaneously.
Parallel Port	An I/O channel for a parallel device, like a printer. Increasingly, other devices such as removable storage drives, scanners etc. share the printer parallel port using a 'pass through' mechanism.
PCL	Printer Command Language, normally in reference to Hewlett-Packard Printer Command Language (HP PCL), but most manufacturers emulating HP PCL leave out the HP.
PDL	Page Description Language: a language for describing the layout and contents of a printed page used with laser printers. The best-known PDLs are Adobe PostScript and HP PCL (Printer Control Language). Both PostScript and modern versions of PCL are object-oriented, describing a page in terms of geometrical objects such as lines, arcs, and circles.
Personal Printer	A small printer, typically producing 4 - 5 p.p.m, which is physically compact to allow easy use on a desk, and sufficiently inexpensive to justify if ownership by an individual for their personal printing needs.
Piezo-Electric	The property of certain crystals that causes them to oscillate when subjected to electrical pressure (voltage).
Pigment Inks	While conventional inks are essentially oil-based dyes, pigment inks consist of tiny chunks of solid pigment suspended in a liquid solution. According to their proponents, pigment inks offer richer, deeper colors and have less tendency to run, bleed or feather.
Pixel	A "picture cell element", commonly used as a misnomer for a dot in laser printing. It is a misnomer because a laser printer dot is an indivisible unit, whereas a pixel may actually comprise several dots arranged in a matrix to form a shade of gray.
PostScript	A page description language developed by Adobe. Generally used by laser printers, PostScript is becoming increasingly common in high-end ink jets too.
P.P.M.	An abbreviation of pages per minute. See speed.
Print Cartridge	A print cartridge is a printer consumable which normally contains all the major replaceable elements in a laser printer, such as toner, and developer.
Print Engine	The mechanism which transcribes a bitmap created by the printer controller into a printed image.
Printer Controller	The dedicated computer in a printer which receives data to be printed from a computer, along with commands defining how the data should be formatted, and uses these to create (rasterize) a bitmap describing the image required on the paper which is then passed to the print engine for transcription to the paper.
Printer Driver	A software utility incorporated into a software application package on a computer which enables the application to determine the commands required by the printer to format data for printing, and which provides the application with information about the facilities provided by the printer.
Printer Dot	The individual pixel in a halftone image. The size of a printer dot is variable, ranging from zero (all white) to the size of the halftone screen (all black).
Production Printer	A large heavy-duty printer designed for almost continuous printing in a production environment, either for large quantities of small documents such as invoices and account statements, or for small quantities of large documents such as reports, short-run books, newsletters etc.
Q thru Z
Raster Image	An image defined as a set of dots/pixels in a column-and-row format. See also Bitmap.
Rasterization	The process of converting data and command received from a computer into a bitmap containing an image to be printed.
Rendering	The process of translating high-level print commands into a raster image.
Resident Font	Any font which is built-in to a printer by the manufacturer as one of the standard features.
Resolution	The number of individual dots a printer can print in a given area. Expressed as dots per inch.
RGB	Red, Green, Blue. A color encoding method normally used on computer displays in which each color to be displayed is described in the proportions of Red, Green, and Blue required to make the color.
Scaleable Font	A font which can be scaled to any size, used as an alternative term for an outline font.
Sixel Graphics	A method of encoding bitmap graphics so that they may be reliably transmitted using serial communication links.
Soft Font	An alternative term for a downloaded font.
Software Driver	A generic term for a software utility such as a printer driver.
Speed	Throughput of a laser or ink jet printer measured in p.p.m or i.p.m.
Toner	A special type of ink used by copy machines and laser printers. Toner consists of a dry, powdery substance that is electrically charged so that it adheres to a drum, plate, or piece of paper charged with the opposite polarity.
Toner Cartridge	A cartridge or cassette which holds toner for ease of loading into a printer.
True Black	Black produced by a separate black ink rather than the 'composite black' produced from a mixture of cyan, magenta and yellow. See also Composite Black.
TrueType	A font definition format for outline fonts which is used by Microsoft Windows for the creation of screen fonts and downloaded fonts.
Vector Graphics	A method of describing lines and curves as mathematical equations or vectors.
Warm-up Time	The time taken after switching on for a printer to achieve a state where it is ready to print. The warm-up time is normally dictated by the time taken to heat up the fuser to its operating temperature.
Workgroup Printer	A medium-sized laser printer designed to handle the printing requirements of several users, normally attached to a LAN or multi-user computer.
WPS	Windows Print System: the scheme supported by Windows 95 in which the operating system spools data from an application in Enhanced Metafile Format (EMF), instead of raw printer data. The spooler interprets the data in the background and then passes appropriate commands to the printer. Like with GDI, all the processing is done on the PC.

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