Image Writer

Impact Line Matrix Printers Printer

Daisay Wheel Printer

IBM Electromatic PRINTERS Compact Photo

HP Deskjet

Non-Impact Laser Printer Printers

Xerography

Inkjet Printer

Printers

Impact Printers Non-Impact Printers  Compact Photo  Image Writer HP Deskjet  Line Matrix Printer Laser Printer  Daisy Wheel Printer  IBM Electromatic Table Inkjet Printer

Printer

In computing, a printer is a peripheral which produces a text and/or graphics of documents stored in electronic form, usually on physical print media such as or transparencies. Many printers are primarily used as local peripherals, and are attached by a printer cable or, in most newer printers, a USB cable to a computer which serves as a document source. Some printers, commonly known as network printers, have built-in network interfaces, typically wireless and/or Ethernet based, and can serve as a hard copy device for any user on the network. Individual printers are often designed to support both local and network connected users at the same time. In addition, a few modern printers can directly interface to electronic media such as memory cards, or to image capture devices such as digital cameras, scanners; some printers are combined with a scanners and/or in a single unit, and can function as . Printers that include non-printing features are sometimes called multifunction printers (MFP), multi-function devices (MFD), or all-in-one (AIO) printers. Most MFPs includeprinting, scanning, and copying among their many features. Consumer and some commercial printers are designed for low-volume, short-turnaround print jobs; requiring virtually no setup time to achieve a hard copy of a given document. However, printers are generally slow devices (30 pages per minute is considered fast; and many inexpensive consumer printers are far slower than that), and the cost per page is actually relatively high. However, this is offset by the on-demand convenience and project management costs being more controllable compared to an out-sourced solution. The remains the machine of choice for high-volume, professional publishing. However, as printers have improved in quality and performance, many jobs which used to be done by professional print shops are now done by users on local printers; see desktop publishing. Local printers are also increasingly taking over the process of photofinishing as digital photo printers become commonplace. The world's first computer printer was a 19th century mechanically driven apparatus invented by Charles Babbage for his Difference Engine.[1] A virtual printer is a piece of computer software whose user interface and API resemble that of a , but which is not connected with a physical computer printer.

 Impact printers

 Refers to a class of printers that work by banging a head or needle against an ribbon to make a mark on the paper. This includes dot-matrix printers, daisy-wheel printers, and line printers. In contrast, laser and ink-jet printers are nonimpact printers. The distinction is important because impact printers tend to be considerably noisier than nonimpact printers but are useful for multipart forms such as invoices.

5 types of impact printer are -

1. Dot Matrix Printer :

A dot matrix printer or impact matrix printer is a type of computer printer with a print head that runs back and forth, or in an up and down motion, on the page and prints by impact, striking an ink-soaked cloth ribbon against the paper, much like the print mechanism on a . However, unlike a typewriter or daisy wheel printer, letters are drawn out of a dot matrix, and thus, varied fonts and arbitrary graphics can be produced. Because the printing involves mechanical pressure, these printers can create carbon copies and carbonless copies. Each dot is produced by a tiny metal rod, also called a "wire" or "pin", which is driven forward by the power of a tiny electromagnet or solenoid, either directly or through small levers (pawls). Facing the ribbon and the paper is a small guide plate (often made of an artificial jewel such as sapphire orruby[1]) pierced with holes to serve as guides for the pins. The moving portion of the printer is called the print head, and when running the printer as a generic text device generally prints one line of text at a time. Most dot matrix printers have a single vertical line of dot-making equipment on their print heads; others have a few interleaved rows in order to improve dot density.These machines can be highly durable[2]. When they do wear out, it is generally due to ink invading the guide plate of the print head, causing grit to adhere to it; this grit slowly causes the channels in the guide plate to wear from circles into ovals or slots, providing less and less accurate guidance to the printing wires. Eventually, even with tungsten blocks and titanium pawls, the printing becomes too unclear to read.Although nearly all inkjet, thermal, and laser printers print closely-spaced dots rather than continuous lines or characters, it is not customary to call them dot matrix printers.

2. Image Writer :

The ImageWriter is a serial based dot matrix printer introduced by Apple Computer in late 1983.The printer was essentially a re-packaged 9-pin dot matrix printer from C. Itoh Electronics (model C. Itoh 8510, with modified ROM and pinout), released the same year. It was introduced as a replacement for the earlier parallel-based Apple Dot Matrix Printer/DMP (also a C. Itoh model) and, while primary intended for the Apple II, worked across Apple's entire computer product line. The ImageWriter could produce images as well as text, up to a resolution of 144 DPI and a speed of about 120 CPS. In text mode, the printer was logic-seeking, meaning it would print with the head moving in both directions while it would print only in one direction for graphics and Near Letter Quality. The ImageWriter was also supported by the Macintosh 128K computer, the original Mac. Apple wanted a graphical printer for the Mac, and had introduced the ImageWriter primarily to support the new machine. This permitted it to produce WYSIWYG output from the screen of the computer, which was an important aspect for promoting the concept of the GUI and, later, desktop publishing. Quality was adequate rather than startling. Another feature offered was a built-in self test, which could be invoked by holding down the form feed button while powering up the printer. The ImageWriter can be supported by Microsoft Windows-based PC's by using the included C. Itoh 8510 compatible driver. The ImageWriter was succeeded by the ImageWriter II in late 1985.

3. Line Matrix Printer :

A line matrix printer is a computer printer that is a compromise between a lineprinter and a dot matrix printer. Basically, it prints a page-wide line of dots. It builds up a line of text by printing lines of dots.Robert A. Kleist and business partner Gordon Barrus created the line matrix printer in 1974, and founded Printronix Inc. They envisioned a new type of printer that would be faster, more reliable and less costly than the cumbersome character printers on the market at the time. The line matrix printing incorporated a unique shuttle-based technology that laid down a matrix of dots and print bar codes and graphics as well as the usual characters. Working out of a garage in Playa Del Ray, Calif., the Printronix team developed a revolutionary 300-line-per-minute (LPM) prototype line matrix printer in just 90 days. Printronix introduced this line matrix printer, called the P300 series, in 1974. Line printers are often used for printing box labels as well as invoices and reports. They print as rapidly as slow lineprinters, and can print bar codes and other graphics as well. When implemented as impact printers, they can be the least expensive to operate, per page. There are numerous mechanisms. One of the most successful is to use a reliable stored energy printer arranged as a comb, and then move the comb back and forth. The forward and backward motion is called shuttling, hence products are often referred to as "shuttle matrix". Speeds increased with products fro manufacturer TallyGenicom formerly Tally with the first 1,400 LPM machines. This was followed by an 1,800 LPM printer which used a newly invented dual hammerbank system where odd and even lines were printed by separate hammerbanks. Dual hammerbank machines however suffer from un-even performance and print quality, and the design was abandoned, replaced by a single hammerbank 1800 LPM model, the T6218. TallyGenicom are also known for other important innovations, adding unique features to line matrix technology. The 'Stay Black' or 'Smart Ribbon' is one. TG was a pioneer of cartridge ribbons, which offer longer life and are easier for users to manage then conventional reel ribbons. By adding a unique ink replenishment system based on a peristaltic pump mechanism,TallyGenicom produced the only impact printers to offer consistent print quality. The increasing importance of user productivity resulted in innovations such as 'Auto-Gap' where for the first time the print mechanism would measure paper thickness (as with dot matrix printers) and, rather than the user, set the gap. This maximises print quality for multi-copies and eliminates user error in this area. Improvements in reliability, resulted in the introduction of a shuttle mechanism with no wear parts, with 'Life Time' warranty.

4. Daisy wheel Printer :

Daisy wheel printers use an impact printing technology invented in 1969 by David S. Lee at Diablo Data Systems. It uses interchangeable pre-formed type elements, each with typically 96 glyphs, to generate high-quality output comparable to premium such as the IBM Selectric, but two to three times faster. Daisy-wheel printing was used in electronic typewriters, word processors and computer systems from 1972. According to Webster's, the daisy wheel is so named because of its resemblance to the flower. By 1980 daisy-wheel printers had become the dominant technology for high-quality print. Dot-matrix impact or thermal printers were used where higher speed was required and poor print quality was acceptable. Both technologies were rapidly superseded for most purposes when dot-based printers—in particular laser printers—that could print any characters or graphics rather than being restricted to a limited character set became able to produce output of comparable quality. Daisy-wheel technology is now found only in some electronic typewriters.

5. IBM Electromatic Table Printing Machine :

The IBM Electromatic Table Printing Machine was a typesetting-quality printer, consisting of a modified IBM Electromatic Proportional Spacing Typewriter connected to a modifiedIBM 016 keypunch. A control panel was used for programming and formatting of the printout. A deck of punched cards containing the table (calculated and punched by other unit record equipment) to be printed was put into the IBM 016, which read them and then controlled the typing of the typewriter through a box containing solenoids that depressed the keys. Printed output could then be photographically reproduced on a printing plate, which would be used in a printing press to make as many copies as needed.

 Non - Impact printers

 Any printer, such as a laser printer, ink-jet printer, LED , that prints without striking the paper, unlike a dot matrix printer which hits the paper with small pins. Non- impact printers are quieter than impact printers, and also faster due the lack of moving parts in the print head. A type of printer that does not operate by striking a head against a ribbon. Examples of nonimpact printers include laser and ink-jet printers. The term nonimpact is important primarily in that it distinguishes quiet printers from noisy (impact) printers.

5 types of impact printer are –

1. Compact photo printer :

A compact photo printer is a stand- alone inkjet printer designed to produce 4 x 6 inch prints from digital cameras. It works without the use of a computer. It is also be known as a portable photo printer or a snapshot printer. Compact photo printers came on the market shortly after the popularity of home photo printing took off in the early 2000s. They were designed as an alternative to developing photos or printing them on a standard inkjet photo printer. The majority of compact photo printers can only print 4" x 6" pictures. Given this limitation, they are not meant to replace standard inkjets. Many manufacturers advertise the cost per page of photos printed on their machines; this theoretically convinces people that they can print their own pictures just as cheaply as retail stores or through online printing services. Most compact photo printers share a similar design. They are small units, usually with large LCDs in order to allow people to browse and edit their photos, as can be done on a computer. The editing options are usually somewhat advanced, allowing the user to crop photos, remove red eye, adjust color settings as well as other functions. Compact photo printers typically feature a large number of connection options, including USB and most memory card formats. Compact photo printers are currently manufactured by most of the leading printer manufacturers such as , Canon, HP, and . While they have increased in popularity in recent years, they still make up a relatively small share of the inkjet printer market.

2. HP Deskjet :

DeskJet is a brand name for inkjet printers manufactured by Hewlett-Packard Company. These printers range from small domestic to large industrial models, although the largest models in the range have generally been dubbed DesignJet. The Macintosh- compatible equivalent was branded as the Deskwriter and competed with Apple's StyleWriter. The HP DeskJet 500 printer has four built-in typefaces and is compatible with TrueType fonts in Windows. The HP DeskJet 500 printer prints on plain paper with a print speed of up to three pages per minute. HP developed thermal in 1979 and launched their ThinkJet in 1984, with color following in 1987 thanks to the PaintJet. Launched in February 1988, the HP Deskjet was the world’s first single-sheet, desktop printer. Originally priced at $995, the reliable HP Deskjet featured an average speed of just 2 pages per minute. It was the least expensive non-impact printer on the market at the time it was introduced, when most small non-laser printers were still impact-based and laser printers remained relatively expensive. The first color DeskJet, the 500C, launched in 1991. Over time, through innovation and large scale production, the price was brought down considerably, being less than half by 1993, by which time inkjet technology and color printing were increasingly popular with consumers and DeskJets had both black and three-color cartridges installed simultaneously. DeskJets are unusual amongst consumer-level inkjet printers in featuring an inexpensive, disposable print head built into the cartridge itself. This allows consistent print quality since the head is replaced frequently, along with the ink. Under some circumstances it may also reduce the need for frequent head- cleaning cycles, which consume ink. This business model of proprietary cartridges has proven very profitable for HP. The DeskJet developed into HP's current DeskJet, DesignJet, PhotoSmart and Professional Series printer lines, all of which are based on thermal inkjet technology. The latest photo printers use several shades of ink to produce a wide color range.

3. Laser Printer :

A laser printer is a common type of computer printer that rapidly produces high quality text and graphics on plain paper. As with digitalphotocopiers and multifunction printers (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 laser beam projects an image of the page to be printed onto an electrically charged rotating drum coated with or, more common in modern printers, organic photoconductors. Photoconductivity removes charge from the areas exposed to light. Dry ink (toner) particles are then electrostatically picked up by the drum's charged aras. The drum then prints the image onto paper by direct contact and heat, which fuses the ink to the paper. 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 in some commercial applications. .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. 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.

4. Xerography :

Xerography (or electrophotography) is a dry photocopying technique invented by in 1938, for which he was awarded U.S. Patent 2,297,691 on October 6, 1942. Carlson originally called his invention electrophotography. It was later renamed xerography—from the Greek roots ξηρός xeros "dry" and - γραφία -graphia "writing"—to emphasize that, unlike reproduction techniques then in use such as , this process used no liquid chemicals. Although Georg Christoph Lichtenberg invented a dry electrostatic printing process in 1778,[1] Carlson's innovation combined electrostatic printing with . Carlson's original process was cumbersome, requiring several manual processing steps with flat plates. It was almost 18 years before a fully automated process was developed, the key breakthrough being use of a cylindrical drum coated with selenium instead of a flat plate. This resulted in the first commercial automatic copier, the 914, being released by Haloid/Xerox in 1960. Xerography is used in most photocopying machines and in laser and LED printers. The first commercial use was hand processing of a flat photosensor with a copy camera and a separate processing unit to produce offset lithographic plates. Today this technology is used in photocopy machines, laser printers, and digital presses such as Xerox iGen3 and Xeikonpresses which are slowly replacing many traditional offset presses in the printing industry for shorter runs. By using a cylinder to carry the photosensor, automatic processing was enabled. In 1960 the automatic was created and many millions have been built since. The same process is used in microform printers and computer output laser or LED printers.The steps of the process are described below as applied on a cylinder, as in a photocopier. Some variants are described within the text. Every step of the process has design variants.

5. Inkjet Printer:

An inkjet printer is a type of computer printer that creates a by propelling droplets of ink onto paper. Inkjet printers are the most commonly used type of printer[1] and range from small inexpensive consumer models to very large professional machines, that can cost up to thousands of dollars The concept of originated in the 19th century, and the technology was first extensively developed in the early 1950s. Starting in the late 1970s inkjet printers that could reproduce digital images generated by computers were developed, mainly by Epson, Hewlett-Packard (HP), and Canon. In the worldwide consumer market, four manufacturers account for the majority of inkjet printer sales: Canon, HP, Epson, andLexmark, a 1991 spin-off from IBM.[3] The emerging ink jet material deposition market also uses inkjet technologies, typically printheads using piezoelectric crystals, to deposit materials directly on substrates. The basic problem with inkjet is the conflicting requirements for a coloring agent that will stay on the surface vs. rapid dispersement of the carrier fluid. Desktop inkjet printers, as used in offices or at home, tend to use aqueous inks based on a mixture of water, glycol and dyes or pigments. These inks are inexpensive to manufacture, but are difficult to control on the surface of media, often requiring specially coated media. HP inks contain sulfonated polyazo black dye (commonly used for dying leather), nitrates and other compounds. Aqueous inks are mainly used in printers with thermal inkjet heads, as these heads require water to perform. While aqueous inks often provide the broadest color gamut and most vivid color, most are not waterproof without specialized coating or after printing. Most Dye-based inks, while usually the least expensive, are subject to rapid fading when exposed to light. Pigment-based aqueous inks are typically more costly but provide much better long-term durability and resistance. Inks marketed as “Archival Quality” are usually pigment- based. Some professional wide format printers use aqueous inks, but the majority in professional use today employ a much wider range of inks, most of which require piezo inkjet heads and extensive maintenance.