• Wired Printers: Printers that use wires to connect to computers are called wired printers. Wired printers are connected using a USB connection.

 

• Wireless Printers: Printers that do not use wires to connect to computers are called wireless printers. Wireless printers are connected using a WIFI connection.

 

 

 

 

Impact printers are printers that typically use a specific type of hammer with which the print heads are attached. When the print command is given, the hammer pushes the print heads onto the ink ribbon. Print heads have different characters, and therefore, they help the ink ribbon to draw the corresponding character on the paper that is placed near the ink ribbon.

 

 

 

Character printers are defined as impact printers that typically print only one character at a time. That means, these printers use a single stroke of a hammer or print head at a time. That's why character printers are slow and cannot print the entire line at once.

 

Character printers are divided into: Dot matrix and Daisy wheel printers

 

• Dot Matrix Printers: Dot matrix printers, also known as pin printers, are the most popular type of impact printer. These printers have a matrix of pins on their print heads to create characters or graphics. Dot-matrix printers usually have 9 to 24 pins in the print head. Thus, they typically print a character using multiple dots created with pins. The more pins in a dot matrix printer, the faster the performance and the better the print quality. Carbon (ink ribbon) is positioned in such a way that it lies between pins and the paper.

 

• Daisy Wheel Printers: Daisy wheel printers are impact printers used primarily to achieve the quality found with typewriters. Because these printers have a mechanism that looks like a daisy (a flower), they are named daisy wheel printers. More specifically, these printers have a wheel/disc that includes print heads and the ends of these print heads have a molded metal character. The overall arrangement looks like daisy petals. When the print command is given, the printer rotates the disk with all its associated characters. As soon as the desired character arrives at the correct print location, the hammer hits the disc and the corresponding character hits the ink ribbon to produce a character on a paper.

 

 

Line printers, also called bar printers, are defined as impact printers that usually print an entire line at a time. This means that these printers use multiple strokes of a hammer with different print heads at once. 

 

Line printer are divided into Drum and Chain printers.

 

• Drum Printers: The drum printer consists of a rotating cylindrical drum with a circular band of characters on its surface. In particular, the surface is divided into tracks equal to the size of the supported printing paper. Tracks have characters set on them. Additionally, the drum printer has a separate hammer for each set of characters. When the print command is given, the drum rotates and when the desired character reaches under the hammer, the hammer quickly strikes the ink ribbon against the paper to print the corresponding character. The paper is placed in such a way that it lies between the hammer and the ribbon of ink. The character is embossed on paper due to the hammer pressure.

 

• Chain Printers: The chain printer consists of a revolving chain with characters set on its surface. These printers typically have a character set of 48, 64, or 96 characters. The chain is connected using gears in such a way that it can rotate horizontally. Like drum printers, chain printers also have several hammers; the total number of hammers is exactly equal to the number of print positions. When the print command is given, the chain rotates with its respective characters. As soon as the desired character reaches the correct print position, the hammer strikes the ink ribbon against the paper and the corresponding character on the chain. In this way, the ink ribbon creates the impression of the corresponding character on paper. Chain printers are not compatible with printing graphics. However, they can print 300 - 500 lines of characters per minute. Like other impact printers, chain printers also make a lot of noise.

 

 

 

Non-impact printers have no hammer to hit the print heads on the ink ribbon. These types of printers do not even use ink ribbon to produce prints. Instead, non-impact printers use various technologies such as laser, electrostatic, xerographic, chemical, or inkjet. 

 

Non-Impact printers are mainly categorized into the following types:

 

 

Inkjet printers are non-impact printers that are widely used by home users and small businesses. These printers make prints by spraying a pattern of ink droplets on the paper with the help of a nozzle or jet. A nozzle has small holes to eject small droplets of ink. Inkjet printers use a special type of ink that usually contains iron material. 

 

Inkjet printers store ink in cartridges. These printers can also produce color prints. For colored inkjet printers, individual cartridges are assembled into printers that can store different colors. Generally, most inkjet printers use four primary colors, such as black, yellow, cyan, and magenta. Thus, color prints are produced by mixing these four colors.

 

 

Laser printers are non-impact printers, typically using laser or non-impact photocopier technology to produce the dots needed to print text or images on paper. When the print command is given, the laser beam produces a text or image structure on a selenium-coated drum by controlling the electric charges. 

 

Laser printers can produce extremely high-resolution prints. This can vary from 300 dpi to 1200 dpi depending on system capacity and memory availability. The higher the DPI, the higher the memory usage and the better the quality. The use of high voltages in these printers causes some carbon emissions. They are still in widespread use in large offices or companies due to their efficient performance compared to other printers.

 

 

Thermal printers use a specific heat-sensitive paper and they produce prints by pushing electrically heated pins onto the paper. The paper used in these printers has a special heat-sensitive coating. It starts getting dark as it gets hot. Therefore, when the hot pins are pushed onto paper, the area concerned becomes darker. 

 

In a thermal printer, the heating element is heated using an electric current. Besides, each character is printed by joining a matrix of dots formed by hot pins. To print characters, the print head is moved to the starting position of the first character. After that, the heat elements of that particular character are turned on, which further help to create a print of the character. 

 

Once the first character is printed, the print head moves to the starting position of the second character and repeats the same process again. The heating elements are switched off in a very short period of time when they are not in use. Thermal printers are also known as electrothermal printers, thermal transfer printers, or thermal wax-transfer printers.