Printers

What is a printer ?
A printer is an external output device that takes data from a computer and generates output in the form of graphics / text on a paper.

Difference between Laser, Inkjet, Thermal and Dot matrix printers :

	Laser Printers	Inkjet Printers	Thermal Printers	Dot Matrix Printers
Invented	1969 by Gary Starkweather.	Developed in the early 1950s.	Texas Instruments in 1965.	Introduced by Digital Equipment Corporation in 1970.
How it works	Laser printers use fine ink powder and heat the powder on the paper.	Inkjet printers spray liquid ink on paper through microscopic nozzles.	It create images using a thermal print head and heat sensitive pigment.	Dot Matrix works having pins pushed against an ink soaked ribbon to paper.
Types	Personal and Office printers. Black and White or color printers.	Continuous (CIJ) and drop-on demand (DOD).	Direct thermal and thermal transfer.	Serial Dot Matrix printers and Line Dot Matrix.
Printing speed	15 to 100 pages per minute.	16 pages per minute.	500 characters per second.	30-550 characters per second.
Quality	Printing quality is adequate. Best for text.	Printing quality is good, best for photos.	Printing quality is good.	Printing quality is bad if printing images. In terms of text, printing is fine.
Color Printing	Basic models only offer black and white, with higher models providing color printing.	Yes provides color printing.	Not a good option for color printing.	Limited color printing.
Black and White Quality	Black and white quality is good, best for bulk printing.	Black and white quality is good, specially with small fonts.	Black and white quality is good.	Can print adequate quality images.
Features	Offers scanners and faxing machines built in. Has bigger input trays, direct connecting facilities (wireless)	Can be used for wider range of papers (photo paper), accurate photographic images, ink is not waterproof.	It utilize a chemically treated material that blackens when the thermal print-head applies heat to its surface. Because it uses heat to create the image.	Used for a variety of purposes. Can print on various types of papers.
Usage	Most commonly used for commercial purposes and places that require black and white printing.	More commonly used for homes as the unit is smaller.	Mostly used for printing labels and barcode etc.	Used for office uses, but now only used by select places such as banks.
Maintenance	For buying it is little bit cost but after that the maintenance is cheaper.	Compare to laser the basic level inkjet printer is cheaper but maintenance(To fill ink refills) is expensive.	Normal	Expensive, parts are hard to come by.
Advantages	Prints faster, bigger input trays.	High print quality, no warm up time, low cost per page	Compared to dot matrix printers, thermal printers are with high printing speed, low noise, clear printing, and easy to use.	Cheaper to print as ribbon is cheap.
Disadvantages	Print quality for color is adequate, device itself is expensive, has health hazards if not properly maintained.	Ink is expensive and it is not waterproof.	Thermal printer, printed documents cannot be permanently stored, if we use the best thermal paper, then can be kept for ten years.	Initial purchase is expensive, maintenance is expensive, it is not fast, makes noise.

What is DPI ?

• DPI stands for “ dots per inch ” It refers to the number of ink or pigment dots per given linear inch of print.
• The higher the DPI the better the print quality.