What is a Printer?A printer is an electromechanical device which convertsthe text and graphical documents from electronic form tothe physical form. Generally they are the externalperipheral devices which are connected with thecomputers or laptops through a cable or wirelessly toreceive input data and print them on the papers. A widerange of printers are available with a variety of featuresranging from printing black and white text documents tohigh quality colored graphic images.
*overview of printers *daisy wheel printers *dot matrix printer *inkjet printer *laser printer*other high quality printers
Overview of printers*categorizing printers*evaluating printers
– Printers fall in two categories*impact printers user device to strike an inked ribbon ,pressing ink from the ribbon on to the paper.*Non-impact printers use different methods to place ink(or another substance) on the page.
When evaluating printers, consider four criteria*image quality –measured in dots per inch(dpi).most printers produce 300 to 600 dpi.*speed-measured in pages per minutes(ppm) or characters per seconds(cps).*initial cost-consumer printers cost $250or less, but professional printers can cost thousands of dollars.*cost of operations-this refers to the cost of supplies used by the printers.
Daisy Wheel PrintersDaisy wheel printers print only charactersand symbols and cannot printgraphics. They are generally slow with aprinting speed of about 10 to 75 charactersper second. By 1980 daisy wheel printerswere the dominant printers for qualityprinting but since the prices of laser andinkjet printers have declined and quality ofdot matrix printers has been improved, thedaisy wheel printers are now obsolete.
Daisy Wheel Printer
how do dot-matrix printers work? performance
These are a common type of impact printers. Its printer’s print head contains a cluster of pins. The printer can push the pins out to form patterns in rapid sequence. The pins press an inkedribbon against the paper, creating an image.
Dot matrix diagram
Lower- resolution dot matrix printers use 9 pins . Higher- resolutions models have 24 pins.Speed is measured in characters per seconds. Some dot matrix printers print 500 cps.
How do ink jet printers work? performance
These are an example of non impact printers. These spray tiny droplet of ink onto the paper. These are available for color and black and white printing.
Ink jet printers offer speed of(2-4 ppm) and resolution of (300-600 dpi). Comparable to low-end laser printer. Ink jet printers are inexpensive and have low operating costs.
How do laser printers work?Performance.
These are non impact printers. They use heat and pressure to bond particles of toner to paper. They are available for color and black and white printing.
They provide resolution from 300- 1200 dpi and higher.Black and white usually produce 4- 16 ppm.Laser printers produce higher- quality print than ink jet printers , but are more expensive.
Print shops and publishers use these printers to create high-quality color images:*Thermal-wax*Dye-sublimation*Fiery*IRIS
Some special types ofprintersPhoto Printer – These inkjet printers arecolor printers that produce photo lab qualitypictures on photo papers. Although they can alsobe used to print documents but they are speciallydesigned for printing the photo. They have a largenumber of nozzles that can print very finedroplets to enhance the image quality. They canprint a 4 x 6 inch photos directly from the digitalcameras without need of a computer.
Dye Sublimation Printers – These are latestinnovative printers that are specially designed for highquality photo printing. They magnetize the ink over acharged paper to produce a very high quality picture.These printers are suitable to photo hobbyists but are aquite expensive.
Portable Printers - They are small lightweight inkjet or thermal printers speciallydesigned for the users to carry out with thelaptops while travelling. Generally theseprinters have a lower quality for image printingand higher cost because of its compact design.
Plotter is a computer printer to print vector graphics. In thepast, plotters were used in applications such as computer-aided design, though they have generally been replaced withwide-format conventional printers. It is now commonplace torefer to such wide-format printers as "plotters," even thoughthey technically arent.* OverviewPen plotters print by moving a pen or other instrument across the surface of a pieceof paper. This means that plotters are restricted to line art, rather than rastergraphics as with other printers. Pen plotters can draw complex line art, includingtext, but do so slowly because of the mechanical movement of the pens. They areoften incapable of efficiently creating a solid region of color, but can hatch an areaby drawing a number of close, regular lines.Plotters offered the fastest way to efficiently produce very large drawings or colorhigh-resolution vector-based artwork when computer memory was very expensiveand processor power was very limited, and other types of printers had limitedgraphic output capabilities.Pen plotters have essentially become obsolete, and have been replaced by large-format inkjet printers and LED toner based printers. Such devices may stillunderstand vector languages originally designed for plotter use, because in manyuses, they offer a more efficient alternative to raster data.
Types of a PlottersThere are three types of Plotters. Theyare the Drum Plotter, The Flat bedplotter and also the Inkjet Plotter. All ofthe three types are explained explicitlyin the below mentioned lines. In thepast a plotter was widely used inapplication such as the CAD, though itdoesnt happen that way anymore.
The Drum PlotterHave you ever sat and spent time to ponder over what a plotter everdid? Apparently, the Drum Plotter happens to be an output device.In case of the Drum Plotters the pen is motioned on a single axistrack while the paper itself moves on a cylindrical drum in a perfectbid to add another axis to the same. Thats the reason why the sizeof the graph is limited only by the width of the drum and can be ofany length.The Flat bed PlotterThis is yet another output device associated with a plotter for it is oneof the three types of a plotter. Now in case of the Flat bed Plotter, thepaper is fixed on a flat surface while the pens are motioned to drawthe image. This is the plotter type which can successfully use severalcolored pens for the purpose so that the effect is different from theregular.
The Inkjet PlotterThis is the third kind of Plotter which is called as the Inkjetplotter. It effectively pushes beads of ink directly onto themedium. In Todays world, virtually all inkjets create colour. Low-end inkjets make the most of the three ink colours (cyan,magenta and yellow), but finally create a complex black that isoften mud-spattered. Four-color inkjets make use of the black inkcreated for pure black printing alone.