A computer printer is a device used to print text or images onto a piece of paper or some other material. The first printer was developed by Charles Babbage in the early 19th century.
There are many types of printers and they all have their own advantages and disadvantages. It could be the expenses in using the printer or it could be the speed at which it prints out a piece of text. Choosing the right printer for the job could mean losing a lot of money or just lots of time.
One commonly used printer is a laser printer. The main advantages are that it can print texts at high speeds and high quality. It prints texts by scanning a laser beam across a photoreceptor. The photoreceptor rolls over the paper printing the text or image onto the surface of the paper. The paper goes through a fuser, which heats the paper so that it can bond the ink onto the paper properly.
Another type of printer is a liquid inkjet printer. This type of printer uses actual ink to form images or words on a page. It cannot print as fast as laser printers but are cheaper to buy than laser printers. However, even though they are cheaper to buy, it is very expensive, as you need to continually replace the ink cartridge. Inkjet printers spray droplets of ink onto an oil coated print drum. The paper rolls over the drum and the ink is printed onto the paper, producing text and images.
There are also other types of printers, which are used for other special purposes and were widely used during some time before laser printers were developed. Some of these printers are thermal, line, daisy wheel and dot-matrix printers.
Thermal color printers use heat to produce color images. Thermal printers work by sticking a wax-based ink on a thermal ribbon onto paper. As the paper and the thermal ribbon process through the printer, the ribbon melts and the wax-based ink sticks onto the paper. The ink cools and is permanently stuck to the paper.
A line printer is a high speed printer in which a line of letters are printed onto a piece of paper at a time. Line printers were able to print 600 to 1200 lines a minute. Line printers worked by using letters engraved onto print wheels which presses onto an ink ribbon that produces letters on a piece of paper.
Daisy wheel printers were pretty similar to typewriters. The printers had daisy wheels which had letters engraved on it. A piece of paper passed through the printers and the daisy wheel rolled onto a ribbon of ink and pressed it onto the paper producing a letter. By rotating the wheel, different characters were created.
Most printers rely on pixels, or dots of ink which are pressed onto paper to form images or letters. The dot matrix printer uses small pins to create dots. There are two types of dot matrix printers. Depending on the printer, it could print out characters in lines or in by each character at a time.
Once, dot matrix printers were the most common printers used. The printer would have 9 to 24 pins on a printer wheel and each was able to print at high quality. Later, the printer was able to print color by changing the ribbon to four colored ribbon. Another wheel is added which lowers each ribbon to print that particular color onto paper.
