Dot Matrix Printer 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 Dot Matrix Printer Compact Photo Image Writer HP Deskjet Line Matrix Printer Laser Printer Daisy Wheel Printer Xerography IBM Electromatic Table Inkjet Printer printing Machine 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 paper 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 fax machines in a single unit, and can function as photocopiers. 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 printing press 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 printer driver, 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 ink 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 typewriter. 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.