Printers

As the passage of time where the wants of human is increased gradually the technology took place in life and made it comfortable. The computer is the one of greatest invention. When computer has become a part of life, users need to share their work with others. However, now days the printer is the most important output device and has become essential, specially in workplaces or offices, where people must have to share 

their different type of information. Printer provides a hard copy of work done in the computer that can be touched and easy to share with others. Printer has solved many problems of any business entity and individuals, before the printer introduced people had to write down all the business activities manually on the paper which usually takes lot of time to write. A printer can print long size report quicker but also can give high letter or picture quality.

            Generally the printers are categorized into two categories:

1                    Impact Printers

2                    Non-Impact Printers

IMPACT PRINTERS

            An impact printer creates an image by using the pins and hammers to press or hit an inked ribbon against the paper. The different types of printers are: -

1.                  Dot Matrix Printers

2.                  Line Printers

3.                  Band Printers

4.                  Daisy Wheel Printers

Dot Matrix Printers

            Dot matrix printers are commonly used in business organizations, because these printers cane produce hard copy of plain text quickly, which include normal letters, reports, large worksheets which wider column information. There are two types of dot matrix printers 40-column printers, which are used to print the letters, memos, envelops and other small reports, usually the paper size is used in this printers is 8½ “X11”.

The second one is larger than the 40-column printer and called 80-columns printer. This type of dot matrix printer can perform all the function, which the 40-column printer is featured, but in addition it can also produce reports on large sheets.

The mechanism of a dot matrix printer that creates an image by using the print head, in which pins are arranged in columnar style. The dot matrix printer receives the print job from computer and push out any pins combination that strikes the ribbon and the ink is transferred onto the paper. The ribbon lies between head and the paper. The print head contained nine to twenty four pins in it. The speed of dot matrix printers is measured in character per second (CPS), and can print at the speed of 50 to 500 CPS. The print head of a slow dot matrix printer can print only from one side, which is left and called one-sided printer where as the faster printer can produce output by printing from both the sides of paper, and called two-sided printers. The lower initial cost and the operation cost increased its popularity, as compare to the others.

Line Printers

As the name of this printer, “Line Printer” shows that the these printers print the entire line at a time the printing mechanism of line printer is the same as the dot matrix has. This printer has the larger print head, than dot matrix, that print the whole line of text. The line printers cannot give high letter quality, if they compete with the dot matrix. The printing speed is much faster, and a line printer can up to 3000 lines of text per minute.

Band Printer

The band printer print through rotating band embossed with alphanumeric characters on it, like the typewriter has. Machine rotates the band to desire character and then a small hammer taps the band and presses the inked ribbon. A good quality band printer can print 2000 line of text per minute.

Daisy Wheel Printers

As compare to the other impact printers these printers are very slow in printing, not in common use and become out of date. However, where the older system is installed they are using these printers. In this printer a spinning wheel is used, where the characters are embossed on its edge and the small hammer hits the wheel pressing the letter or number against the ribbon. These cannot produce graphical documents

NON-IMPACT PRINTERS

There is no physical contact between paper and the printing device, in non-impact printers. The characters are produced on the paper using heat, chemical and spraying system. The kinds of Non-Impact Printers are:

1.                  Inkjet Printers

2.                  Laser Printers

3.                  Thermal Wax Printers

4.                  Dye-Sub Printers

5.                  Photo Printers

6.                  Plotters

Inkjet Printers

The inkjet printers create images using tiny nozzles spraying on the paper. Usually, the inkjet printer has 64 tiny nozzles in its print head. In inkjet printers there are tow cartridges are installed in an inkjet printer one of them is contained black ink and other one has the colored ink. The inkjet printer contains four colors cyan, magenta, yellow and black (CMYK), these colors are different from primary additive colors red, green, and blue, therefore called subtractive colors.  The normal inkjet printer can typically give the minimum resolution of 360 dpi (dots per inch).

Laser Printer

Laser printer is expensive, but is more popular and successful printing device, because of its high-resolution print quality and as well as the faster printing speed. Here the laser beam technology is used in the laser printer that gives the high quality image and the built memory and CPU makes the faster printing speed. Laser beam creates an electric charge any where on the drum, reflecting from a rotating mirror, according to the instruction received from the computer, and the tiny particles of toner which are also have static charge affixes onto the drum and then the shifted on paper, previously charged, after that paper passes through a hot roller, coated with Teflon paper, which bonds the toner t to the paper. A laser printer can give the resolution of 300 dpi to 1800 dpi.

Thermal wax printer

This printer uses the coloured wax coated with a ribbon, they do not spray the colours onto the paper, and instead the colour is malted by a heat source and the ink stick onto the paper. Special coated paper is used in the thermal wax printers, these printer s are used, where the bold colours and the quality graphics is also are required. These printer gives low-cost on higher colour graphics.

Dye-Sub Printers

The Dye-Sublimation printers give a sharp image quality. Dye-Sublimation technology features by a ribbon that contain panels of colour is moved over a focused heat source capable of subtle temperature variation. The dyes shifted from the ribbon onto the paper, where they form area of different colours.

Dye sub Printers are used to get print with high quality colour graphics photo print like thermal wax printer, but are larger in size, has slow printing speed and also have high cost per-page.

Photo Printer

Where the many inkjet and laser printer are being used as photo printers, but not efficiently, therefore, the photo printers are designed specially to print the photos as nearly as the original photograph. However, this printer is slower in speed and printout takes longer time to dry. Photo Printer works like a inkjet printer but are good in result as compare to the inkjet printer in quality, because it sprays lot of tiny drops on to the paper to form an image. A photo printer can print 4”X 6” to 11”X 14” of photo. These printers can be connected to camera directly, without using a computer.

Plotters  

Plotters are special purpose printers. The plotters are in size of a billiard table, and are being used where the construction and engineering drawings need to be printed. Plotters have different technology to perform a print job. Old plotters were mechanical plotters, which uses the robotic arms to create a drawing. In some of the  mechanical plotters an arm moves over a sheet to create images, whether the some them, a robotic arm moves the paper sheet rather then the writing arm, the writing remain stationary.

The latest technology in plotters has replaced the mechanical plotters; such plotters are using the technology of Thermal, electrostatic and inkjet printers. These printers are cheaper, faster and can print large-size drawings then mechanical plotters.