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This article is part of the series on the |
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| Technologies | ||
|---|---|---|
| Phaistos Disc | 1850–1400 BC | |
| Woodblock printing | 200 AD | |
| Movable type | 1040 | |
| Intaglio | 1430s | |
| Printing press | 1439 | |
| Lithography | 1796 | |
| Offset press | by 1800s | |
| Chromolithography | 1837 | |
| Rotary press | 1843 | |
| Flexography | 1890s | |
| Screen-printing | 1907 | |
| Dye-sublimation | 1957 | |
| Photocopier | 1960s | |
| Pad printing | 1960s | |
| Laser printer | 1969 | |
| Dot matrix printer | 1970 | |
| Thermal printer | ||
| Inkjet printer | 1976 | |
| Digital press | 1993 | |
| 3D printing | ||
A laser printer is a common type of computer printer that rapidly produces high quality text and graphics on plain paper. The history of printing began as an attempt to make easier and reduce the cost of reproducing multiple copies of documents fabrics wall papers and so on The Phaistos Disc ( Phaistos Disk, Phaestos Disc) is a disk of fired Clay from the Minoan palace of Phaistos, possibly dating For the use of the technique in art see Woodcut on the technique and Old master print for the history in Europe and Woodblock printing in Japan. Movable type is the system of Printing and Typography that uses movable components to reproduce the elements of a document (usually individual letters or punctuation Intaglio (pronounced in-TAL-yo ɪn'tælɪəʊ is a family of Printmaking techniques in which the image is incised into a surface known as the matrix or plate A printing press is a mechanical device for applying pressure to an inked surface resting upon a medium (such as paper or cloth thereby transferring an image Lithography is a method for Printing using a plate or stone with a completely smooth surface Offset printing is a commonly used Printing technique where the Inked image is transferred (or "offset" from a plate to a rubber blanket then to the Chromolithography is a method for making multi-color prints. This type of color printing stemmed from the process of Lithography, and it includes all types of lithography A rotary printing press is a Printing press in which the images to be printed are curved around a cylinder Flexography (also called surface printing) often abbreviated to flexo, is a method of Printing most commonly used for packaging (labels tape bags Screen printing is a printing technique that uses a woven mesh to support an ink blocking stencil A dye-sublimation printer (or dye-sub printer) is a Computer printer which employs a printing process that uses heat to transfer dye to a medium such as a plastic A photocopier (or copier is a machine that makes Paper copies of documents and other visual images quickly and cheaply Pad printing is a printing process that can transfer a 2-D image onto a 3-D object A dot matrix printer or impact matrix printer refers to a type of Computer printer with a print head that runs back and forth on the page and prints by impact striking For the type of printer which uses sparks and aluminised paper (and is sometimes referred to as a "thermal printer" see Spark printer. Inkjet printers operate by propelling variably-sized droplets of liquid or molten material ( Ink) onto almost any sized page Digital printing is the reproduction of Digital images on a physical surface 3D printing is a category of Rapid prototyping technology A three dimensional object is created by layering and connecting successive cross sections of material As with digital photocopiers and MFPs, laser printers employ a xerographic printing process but differ from analog photocopiers in that the image is produced by the direct scanning of a laser beam across the printer's photoreceptor. A photocopier (or copier is a machine that makes Paper copies of documents and other visual images quickly and cheaply Xerography (or electrophotography) is a Photocopying technique developed by Chester Carlson in 1938 and Patented on October 6
Contents |
Overview
Laser printers have many significant advantages over other types of printers. Unlike impact printers, laser printer speed can vary widely, and depends on many factors, including the graphic intensity of the job being processed. The fastest models can print over 200 monochrome pages per minute (12,000 pages per hour). The fastest color laser printers can print over 100 pages per minute (6000 pages per hour). Very high-speed laser printers are used for mass mailings of personalized documents, such as credit card or utility bills, and are competing with lithography in some commercial applications. Lithography is a method for Printing using a plate or stone with a completely smooth surface
The cost of this technology depends on a combination of factors, including the cost of paper, toner, and infrequent drum replacement, as well as the replacement of other consumables such as the fuser assembly and transfer assembly. Often printers with soft plastic drums can have a very high cost of ownership that does not become apparent until the drum requires replacement.
A duplexing printer (one that prints on both sides of the paper) can halve paper costs and reduce filing volumes. Formerly only available on high-end printers, duplexers are now common on mid-range office printers, though not all printers can accommodate a duplexing unit. Duplexing can also give a slower page-printing speed, because of the longer paper path.
In comparison with the laser printer, most inkjet printers and dot-matrix printers simply take an incoming stream of data and directly imprint it in a slow lurching process that may include pauses as the printer waits for more data. Inkjet printers operate by propelling variably-sized droplets of liquid or molten material ( Ink) onto almost any sized page A dot matrix printer or impact matrix printer refers to a type of Computer printer with a print head that runs back and forth on the page and prints by impact striking A laser printer is unable to work this way because such a large amount of data needs to output to the printing device in a rapid, continuous process. The printer cannot stop the mechanism precisely enough to wait until more data arrives, without creating a visible gap or misalignment of the dots on the printed page.
Instead the image data is built up and stored in a large bank of memory capable of representing every dot on the page. The requirement to store all dots in memory before printing has traditionally limited laser printers to small fixed paper sizes such as letter or A4. Most laser printers are unable to print continuous banners spanning a sheet of paper two meters long, because there is not enough memory available in the printer to store such a large image before printing begins.
History
The laser printer, based on a modified xerographic copier, was invented at Xerox in 1969 by researcher Gary Starkweather, who had a fully functional networked printer system working by 1971. Xerox Corporation ( (name ˈziːrɒks is a global document management company which manufactures and sells a range of color and black-and-white printers, multifunction Gary K Starkweather is an American engineer and inventor In 1969 Starkweather invented the Laser printer at Xerox 's Webster research center Year 1971 ( MCMLXXI) was a Common year starting on Friday (link will display full calendar of the 1971 Gregorian calendar. [1][2] Laser printing eventually became a multibillion-dollar business for Xerox.
The first commercial implementation of a laser printer was the IBM model 3800 in 1976, used for high-volume printing of documents such as invoices and mailing labels. International Business Machines Corporation abbreviated IBM and nicknamed "Big Blue", is a multinational Computer Technology Year 1976 ( MCMLXXVI) was a Leap year starting on Thursday (link will display full calendar of the Gregorian calendar. It is often cited as "taking up a whole room," implying that it was a primitive version of the later familiar device used with a personal computer. A personal computer ( PC) is any Computer whose original sales price size and capabilities make it useful for individuals and which is intended to be operated While large, it was designed for an entirely different purpose. Many 3800s are still in use.
The first laser printer designed for use with an individual computer was released with the Xerox Star 8010 in 1981. The Star Workstation, officially known as the Xerox 8010 Information System, was introduced Year 1981 ( MCMLXXXI) was a Common year starting on Thursday (link displays the 1981 Although it was innovative, the Star was an expensive ($17,000) system that was purchased by only a relatively small number of businesses and institutions. After personal computers became more widespread, the first laser printer intended for a mass market was the HP LaserJet 8ppm, released in 1984, using a Canon engine controlled by HP software. A personal computer ( PC) is any Computer whose original sales price size and capabilities make it useful for individuals and which is intended to be operated LaserJet is the brand name used by the American computer company Hewlett-Packard (HP for their line of dry electrophotographic (DEP Laser printers Year 1984 ( MCMLXXXIV) was a Leap year starting on Sunday (link displays the 1984 Gregorian calendar) is a Japanese Multinational corporation that specializes in imaging and optical products including Cameras photocopiers and Computer printers The HP LaserJet printer was quickly followed by laser printers from Brother Industries, IBM, and others. ( is a diversified Japanese company that produces a wide variety of products including Sewing machines large Machine tools Label printers and Typewriters International Business Machines Corporation abbreviated IBM and nicknamed "Big Blue", is a multinational Computer Technology
Most noteworthy was the role the laser printer played in popularizing desktop publishing with the introduction of the Apple LaserWriter for the Apple Macintosh, along with Aldus PageMaker software, in 1985. Desktop publishing (also known as DTP) combines a Personal computer and WYSIWYG page layout Software to create Publication Documents Apple Inc, ( formerly Apple Computer Inc, is an American Multinational corporation with a focus on designing and manufacturing Consumer electronics The Apple LaserWriter was one of the first Laser printers available to the mass market Macintosh, commonly nicknamed Mac is a Brand name which covers several lines of Personal computers designed developed and marketed by Apple Inc PageMaker was the first Desktop publishing program introduced in 1985 by Aldus Corporation, initially for the Apple Macintosh but soon after also Year 1985 ( MCMLXXXV) was a Common year starting on Tuesday (link displays 1985 Gregorian calendar) With these products, users could create documents that would previously have required professional typesetting. Typesetting involves the presentation of textual material in graphic form on Paper or some other medium.
As with most electronic devices, the cost of laser printers has fallen markedly over the years. In 1985 the HP LaserJet sold for $2995. 00 and weighed 71 pounds (32 kg). The Apple LaserWriter (which shipped with a more powerful processor and the Postscript page description language) weighed about 70 lb and cost almost $7000. 00. (Work rules in the factory producing the Laserwriter forbade any worker lifting the printer unassisted. ) Today a comparable laser printer with more memory, a higher speed and duplexing capability costs about $300. 00. A bare-bones laser printer costs less than $100. 00.
How it works
There are typically seven steps involved in the laser printing process:
Raster image processing
Each horizontal strip of dots across the page is known as a raster line or scan line. Xerography (or electrophotography) is a Photocopying technique developed by Chester Carlson in 1938 and Patented on October 6 A Raster scan, or raster scanning, is the pattern of image detection and reconstruction in television and is the pattern of image storage and transmission used in most computer A scan line is one line or row in a Raster scanning pattern such as a video line on a Cathode ray tube (CRT display of a television or computer Creating the image to be printed is done by a Raster Image Processor (RIP), typically built into the laser printer. A raster image processor (RIP is a component used in a Printing system which produces a raster image also know as a Bitmap. The source material may be encoded in any number of special page description languages such as Adobe PostScript (PS) or HP Printer Command Language (PCL), as well as unformatted text-only data. Printer Command Language, more commonly referred to as PCL, is a Page description language (PDL developed by HP as a printer protocol and The RIP uses the page description language to generate a bitmap of the final page in the raster memory. Once the entire page has been rendered in raster memory, the printer is ready to begin the process of sending the rasterized stream of dots to the paper in a continuous stream.
Charging
A corona wire (in older printers) or a primary charge roller projects an electrostatic charge onto the photoreceptor (otherwise named the photoconductor unit), a revolving photosensitive drum or belt, which is capable of holding an electrostatic charge on its surface while it is in the dark. In Electricity, a corona discharge is an Electrical discharge brought on by the Ionization of a Fluid surrounding a conductor, which Electrostatics is the branch of Science that deals with the Phenomena arising from what seems to be stationary Electric charges Since Classical
Exposing
The laser is aimed at a rotating polygonal mirror, which directs the laser beam through a system of lenses and mirrors onto the photoreceptor. The beam sweeps across the photoreceptor at an angle to make the sweep straight across the page; the cylinder continues to rotate during the sweep and the angle of sweep compensates for this motion. The stream of rasterized data held in memory turns the laser on and off to form the dots on the cylinder. (Some printers switch an array of light emitting diodes spanning the width of the page, but these devices are not "Laser Printers". ) Lasers are used because they generate a narrow beam over great distances. The laser beam neutralizes (or reverses) the charge on the white parts of the image, leaving a static electric negative image on the photoreceptor surface to lift the toner particles. For the science of static charges see Electrostatics Static electricity refers to the accumulation of excess Electric charge in a For the Irish surname see Toner (surname. Toner is a powder used in Laser printers and Photocopiers to form
Developing
The surface with the latent image is exposed to toner, fine particles of dry plastic powder mixed with carbon black or coloring agents. For the Irish surname see Toner (surname. Toner is a powder used in Laser printers and Photocopiers to form The charged toner particles are given a negative charge, and are electrostatically attracted to the photoreceptor where the laser wrote the latent image. Because like charges repel, the negatively charged toner will not touch the drum where light has not removed the negative charge.
The overall darkness of the printed image is controlled by the high voltage charge applied to the supply toner. Once the charged toner has jumped the gap to the surface of the drum, the negative charge on the toner itself repels the supply toner and prevents more toner from jumping to the drum. If the voltage is low, only a thin coat of toner is needed to stop more toner from transferring. If the voltage is high, then a thin coating on the drum is too weak to stop more toner from transferring to the drum. More supply toner will continue to jump to the drum until the charges on the drum are again high enough to repel the supply toner. At the darkest settings the supply toner voltage is high enough that it will also start coating the drum where the initial unwritten drum charge is still present, and will give the entire page a dark shadow.
Transferring
The photoreceptor is pressed or rolled over paper, transferring the image. Higher-end machines use a positively charged transfer roller on the back side of the paper to pull the toner from the photoreceptor to the paper.
Fusing
The paper passes through rollers in the fuser assembly where heat and pressure (up to 200 Celsius) bond the plastic powder to the paper.
One roller is usually a hollow tube (heat roller) and the other is a rubber backing roller (pressure roller). A radiant heat lamp is suspended in the center of the hollow tube, and its infrared energy uniformly heats the roller from the inside. For proper bonding of the toner, the fuser roller must be uniformly hot.
The fuser accounts for up to 90% of a printer's power usage. The heat from the fuser assembly can damage other parts of the printer, so it is often ventilated by fans to move the heat away from the interior. The primary power saving feature of most copiers and laser printers is to turn off the fuser and let it cool. Resuming normal operation requires waiting for the fuser to return to operating temperature before printing can begin.
Some printers use a very thin flexible metal fuser roller, so there is less mass to be heated and the fuser can more quickly reach operating temperature. This both speeds printing from an idle state and permits the fuser to turn off more frequently to conserve power.
If paper moves through the fuser more slowly, there is more roller contact time for the toner to melt, and the fuser can operate at a lower temperature. Smaller, inexpensive laser printers typically print slowly, due to this energy-saving design, compared to large high speed printers where paper moves more rapidly through a high-temperature fuser with a very short contact time.
Cleaning
When the print is complete, an electrically neutral soft plastic blade cleans any excess toner from the photoreceptor and deposits it into a waste reservoir, and a discharge lamp removes the remaining charge from the photoreceptor.
Toner may occasionally be left on the photoreceptor when unexpected events such as a paper jam occur. The toner is on the photoconductor ready to apply, but the operation failed before it could be applied. The toner must be wiped off and the process restarted.
Waste toner cannot be reused for printing because it can be contaminated with dust and paper fibers. A quality printed image requires pure, clean toner. Reusing contaminated toner can result in splotchy printed areas or poor fusing of the toner into the paper. There are some exceptions however, most notably some Brother and Toshiba laser printers, which use a patented method to clean and recycle the waste toner. ( is a diversified Japanese company that produces a wide variety of products including Sewing machines large Machine tools Label printers and Typewriters ( is a multinational conglomerate manufacturing company headquartered in Tokyo, Japan. [3][4]
Multiple steps occurring at once
Once the raster image generation is complete all steps of the printing process can occur one after the other in rapid succession. This permits the use of a very small and compact unit, where the photoreceptor is charged, rotates a few degrees and is scanned, rotates a few more degrees and is developed, and so forth. The entire process can be completed before the drum completes one revolution.
Different printers implement these steps in distinct ways. Some "laser" printers actually use a linear array of light-emitting diodes to "write" the light on the drum (see LED printer). A laser is a device that emits Light ( Electromagnetic radiation) through a process called Stimulated emission. An LED printer is a recently-developed type of Computer printer. The toner is based on either wax or plastic, so that when the paper passes through the fuser assembly, the particles of toner melt. Wax has traditionally referred to a substance that is secreted by Bees ( Beeswax) and used by them in constructing their Plastic is the general common term for a wide range of synthetic or semisynthetic organic solid materials suitable for the manufacture of industrial products The paper may or may not be oppositely charged. The fuser can be an infrared oven, a heated pressure roller, or (on some very fast, expensive printers) a xenon flash lamp. A xenon flash lamp is an Electric glow discharge lamp designed to produce extremely intense incoherent, full-spectrum white light for very short durations The Warm Up process that a laser printer goes through when power is initially applied to the printer consists mainly of heating the fuser element. Many printers have a toner-conservation mode or "economode", which can be substantially more economical with fuser consumption at the price of slightly lower contrast.
Color laser printers
Color laser printers use colored toner (typically, but not always cyan, magenta, yellow, and black-- see CMYK) in four steps or passes. Cyan (saɪæn from Greek κυανός / kyanos, meaning "blue" may be used as the name of any of a number of a range of colors in the blue/green part of Magenta is a purplish red Color evoked by lights with less power in yellowish-green Wavelengths than in blue and red wavelengths ( complements of magenta have Yellow is the Color evoked by light that stimulates both the L and M (long and medium wavelength Cone cells of the Retina about equally Black is the Color of objects that do not emit or Reflect Light in any part of the Visible spectrum; they absorb all such frequencies of CMYK (short for '''c'''yan, '''m'''agenta, '''y'''ellow, and k ey ( Black) and often referred to as process color Color adds complexity to the printing process because very slight misalignments known as registration errors can occur between printing each color, causing unintended color fringing, blurring, or light/dark streaking along the edges of colored regions.
To permit a high registration accuracy, some color laser printers use a large belt the size of a full sheet of paper to generate the image. All four layers of toner are precisely applied to the belt, and the combined layers are then applied to the paper in a single step.
Color laser printers typically require four times as much memory as a monochrone printer to print the same size document, because each of the four CMYK color separations needs to be rasterized and stored in memory before printing can begin.
Laser printer maintenance
Most consumer and small business laser printers use a cartridge that combines the photoreceptor (sometimes called "photoconductor unit") with the supply toner and waste toner bottles and various wiper blades. When the supply toner is consumed, replacing the cartridge automatically replaces the photoreceptor, waste toner bottle, and blades.
Some small consumer printers use a separate toner bottle that can be replaced several times separately from the photoreceptor, allowing for a much lower cost of operation. High-volume business laser printers separate all components into individual modules.
After printing about fifty thousand pages, typical maintenance is to vacuum the mechanism, and clean or replace the paper handling rollers. The rollers have a thick rubber coating, which eventually suffers wear and becomes covered with slippery paper dust. They can usually be cleaned with a damp lint-free rag and there are chemical solutions that can help restore the traction of the rubber.
After one hundred thousand pages, it is common for the fuser assembly to either wear out or need cleaning. The fuser heating rollers are often coated with an oil that prevents toner from sticking to the rollers. A small amount of the oil coating is absorbed by each piece of paper passing through the fuser, eventually requiring the oil supply to be replenished or the pressure roller assembly to be completely replaced. It is common for the fuser assembly to be left unmaintained until the toner starts sticking to the rollers, which creates a repeating ragged line on every printed page due to the rollers not being smooth anymore.
Color laser printers are typically more expensive and higher maintenance than monochrome laser printers since they contain more imaging components. Color laser printers intended for high volume use may require supplies that monochrome printers do not use, while the least expensive consumer color laser printers are expected to wear out and fail four times faster during color printing, compared to monochrome printing.
Due to current market incentives, the least expensive consumer color laser printers often cost less than the total value of the replacement parts inside the printer. The photoreceptor assembly for example may last 100,000 pages but may cost as much to replace as buying a new printer with new toner cartridges included.
Steganographic anti-counterfeiting ("secret") marks
Many modern color laser printers mark printouts by a nearly invisible dot raster, for the purpose of identification. Printer steganography is a type of Steganography produced by Color printers including HP and Xerox brand color Laser printers, where The dots are yellow and about 0. 1 mm in size, with a raster of about 1 mm. This is purportedly the result of a deal between the US government and printer manufacturers to help track counterfeiters. The federal government of the United States is the central United States Governmental body established by the United States Constitution. A counterfeit is an imitation that is made usually with the intent to deceptively represent its content or origins [5]
The dots encode data such as printing date, time, and printer serial number in binary-coded decimal on every sheet of paper printed, which allows pieces of paper to be traced by the manufacturer to identify the place of purchase, and sometimes the buyer. In Computing and electronic systems binary-coded decimal ( BCD) is an encoding for decimal numbers in which each digit is represented by its own binary Digital rights advocacy groups such as the Electronic Frontier Foundation are concerned that this is a threat to the privacy and anonymity of those who print. The Electronic Frontier Foundation ( EFF) is an international non-profit advocacy and legal organization based in the United States with the stated purpose of being dedicated [6]
Safety hazards, health risks, and precautions
Shock hazards
Although modern printers include many safety interlocks and protection circuits, it is possible for a high voltage or a residual voltage to be present on the various rollers, wires, and metal contacts inside a laser printer. Interlocking is a method of preventing undesired states in a state machine, which in a general sense can include any electrical electronic or mechanical device or system Care should be taken to avoid unnecessary contact with these parts to reduce the potential for painful electrical shock.
Toner clean-up
Toner particles are designed to have electrostatic properties and can develop static-electric charges when they rub against other particles, objects, or the interiors of transport systems and vacuum hoses. Because of this and its small particle size, toner should not be vacuumed with a conventional home vacuum cleaner. Static discharge from charged toner particles can ignite dust in the vacuum cleaner bag or create a small explosion if sufficient toner is airborne. This may damage the vacuum cleaner or start a fire. In addition, toner particles are so fine that they are poorly filtered by conventional household vacuum cleaner filter bags and blow through the motor or back into the room.
Toner particles melt (or fuse) when warmed. Small toner spills can be wiped up with a cold, damp cloth.
If toner spills into the laser printer, a special type of vacuum cleaner with an electrically conductive hose and a high efficiency (HEPA) filter may be needed for effective cleaning. A high efficiency Particulate air or HEPA (ˈhɛpə filter is a type of high-efficiency Air filter. These are called ESD-safe (Electrostatic Discharge-safe) or toner vacuums. Similar HEPA-filter equipped vacuums should be used for clean-up of larger toner spills.
Toner is easily cleaned from most water-washable clothing. As toner is a wax or plastic powder with a low melting temperature, it must be kept cold during the cleaning process. Washing a toner stained garment in cold water is often successful. Even warm water is likely to result in permanent staining. The washing machine should be filled with cold water before adding the garment. Washing through two cycles improves the chances of success. The first may use hand wash dish detergent, with the second cycle using regular laundry detergent. Residual toner floating in the rinse water of the first cycle will remain in the garment and may cause a permanent graying. A clothes dryer or iron should not be used until it is certain that all the toner has been removed.
Ozone hazards
As a natural part of the printing process, the high voltages inside the printer can produce a corona discharge that generates a small amount of ionized oxygen and nitrogen, forming ozone and nitrogen oxides. In Electricity, a corona discharge is an Electrical discharge brought on by the Ionization of a Fluid surrounding a conductor, which OZONE is an object oriented Operating system written in the C programming language. The term nitrogen oxide typically refers to any Binary compound of Oxygen and Nitrogen, or to a mixture of such compounds Nitric In larger commercial printers and copiers, a carbon filter in the air exhaust stream breaks down these oxides to prevent pollution of the office environment.
However, some ozone escapes the filtering process in commercial printers, and ozone filters are not used in many smaller consumer printers. When a laser printer or copier is operated for a long period of time in a small, poorly ventilated space, these gases can build up to levels at which the odor of ozone or irritation may be noticed. A potential for creating a health hazard is theoretically possible in extreme cases.
Respiratory health risks
According to a recent study conducted in Queensland, Australia, some printers emit sub-micrometre particles which some suspect may be associated with respiratory diseases. A micrometre ( American spelling: micrometer; symbol µm) is one millionth of a Metre, or equivalently one thousandth of a Millimetre [7] Of 63 printers evaluated in the Queensland University of Technology study, 17 of the strongest emitters were made by Hewlett-Packard and one by Toshiba. ( is a multinational conglomerate manufacturing company headquartered in Tokyo, Japan. The machine population studied, however, was only those machines already in place in the building and was thus biased toward specific manufacturers. The authors noted that particle emissions varied substantially even among the same model of machine. According to Professor Morawska of Queensland University, one printer emitted as many particles as a burning cigarette. [8]
- "The health effects from inhaling ultrafine particles depend on particle composition, but the results can range from respiratory irritation to more severe illness such as cardiovascular problems or cancer. Ultrafine particles ( UFPs) are Nanoscale, less than 100 Nanometres Clusters of UFPs can be seen with the naked eye This is an article about the rock music band "Circulatory System" Cancer (medical term Malignant Neoplasm) is a class of Diseases in which a group of cells display uncontrolled " (Queensland UT). Queensland University of Technology (QUT is located in Brisbane, Queensland, and is one of Australia's largest universities. [9]
A 2006 study in Japan found that laser printers increase concentrations of styrene, xylenes, and ozone, and that ink-jet printers emitted pentanol. Styrene, also known as vinyl benzene as well as many other names (see table is an Organic compound with the Chemical formula C6H5CH=CH2 o-Xylene|m-Xylene|p-XyleneThe term xylene or xylol refers to a mixture of three Benzene derivatives which is used as a Solvent in the Printing OZONE is an object oriented Operating system written in the C programming language. Inkjet printers operate by propelling variably-sized droplets of liquid or molten material ( Ink) onto almost any sized page [10]
Muhle et al. (1991) reported that the responses to chronically inhaled copying toner, a plastic dust pigmented with carbon black, titanium dioxide and silica were also similar qualitatively to titanium dioxide and diesel exhaust. [11]
See also
- Daisy wheel printer
- Dot matrix printer
- Inkjet printer
- LED printer
- Thermal printer
- Dye-sublimation printer
- Steganography
External links
- Howstuffworks "How Laser Printers Work"
- Is Your Printer Spying On You? (by EFF)
- Detailed description, modelling and simulation of the electrophotographic print process (technical; 7.2MB)
- Xerographic Color Technology (pdf), Katun (supplier of OEM-compatible imaging supplies, photoreceptors, and parts), July 1999
References
- ^ Edwin D. A daisy wheel printer is a printing technology which produces high-quality output comparable to that produced by high-end typewriters such as the IBM Selectric. A dot matrix printer or impact matrix printer refers to a type of Computer printer with a print head that runs back and forth on the page and prints by impact striking Inkjet printers operate by propelling variably-sized droplets of liquid or molten material ( Ink) onto almost any sized page An LED printer is a recently-developed type of Computer printer. For the type of printer which uses sparks and aluminised paper (and is sometimes referred to as a "thermal printer" see Spark printer. A dye-sublimation printer (or dye-sub printer) is a Computer printer which employs a printing process that uses heat to transfer dye to a medium such as a plastic Steganography is the art and science of writing hidden messages in such a way that no one apart from the sender and intended recipient even realizes there is a hidden message The Electronic Frontier Foundation ( EFF) is an international non-profit advocacy and legal organization based in the United States with the stated purpose of being dedicated Reilly (2003). Milestones in Computer Science and Information Technology. Greenwood Press. ISBN 1573565210.
- ^ Roy A. Allan (2001). A History of the Personal Computer: The People and the Technology. Allan Publishing. ISBN 0968910807.
- ^ U.S. Patent 5231458 - Printer which utilizes previously used developer
- ^ Simplified explanation of Brother waste toner recycling process at fixyourownprinter.com
- ^ Electronic Frontier Foundation- privacy on printers
- ^ Electonic Frontier Foundation Threat to privacy
- ^ Particle Emission Characteristics of Office Printers.
- ^ Particle Emission Characteristics of Office Printers.
- ^ Study reveals the dangers of printer pollution.
- ^ Are Laser Printers Hazardous to Your Health? - Yahoo! News.
- ^ 11.6 METALS. 070821 epa. gov
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