Types of Printers

Inkjet

What is an INKJET PRINTER and what is it for?

“An inkjet printer is any printer that places extremely small droplets of ink onto paper to create an image.” It is made for printing documents, spreadsheets, images and other things that we normally print. “If you ever look at a piece of paper that has come out of an inkjet printer, you know that:

- The dots are extremely small (usually between 50 and 60 microns in diameter), so small that they are tinier than the diameter of a human hair (70 microns)!

- The dots are positioned very precisely, with resolutions of up to 1440x720 dots per inch (dpi).

- The dots can have different colors combined together to create photo-quality images.”

How do INKJET PRINTERS work?

There are two main technologies behind inkjet printers: Thermal Bubble and Piezoelectric. The thermal bubble method, or more commonly referred to as bubble jet, uses tiny resistors to create heat. This heat “vaporizes ink to create a bubble. As the bubble expands, some of the ink is pushed out of a nozzle onto the paper. When the bubble “pops” (collapses), a vacuum is created. This pulls more ink into the print head from the cartridge. A typical bubble jet print head has 300 or 600 tiny nozzles, and all of them can fire a droplet simultaneously.”

The Piezoelectric method, on the other hand, uses piezo crystals. “A crystal is located at the back of the ink reservoir of each nozzle. The crystal receives a tiny electric charge that causes it to vibrate. When the crystal vibrates inward, it forces a tiny amount of ink out of the nozzle. When it vibrates out, it pulls some more ink into the reservoir to replace the ink sprayed out.”

Laser Printer

A laser printer, as the name suggests, is a type of printer that utilizes a laser beam to produce an image on a drum. They produce very high-quality print and are capable of printing an almost unlimited variety of fonts and graphics. They are much quieter than dot-matrix or daisy-w heel printers and are also relatively fast, although not as fast as some dot-matrix printers. The speed of laser printers ranges from about 4 to 20 pages of text per minute (ppm). A typical rate of 6 ppm is equivalent to about 40 characters per second (cps). One of the chief characteristics of laser printers is their resolution or how many dots per inch (dpi) they lay down. The available resolutions range from 300 dpi at the low end to 1,200 dpi at the high end.

The laser printer works in the same way as copy machines do. The light of the laser alters the electrical charge on the drum wherever it hits. The drum is then rolled through a reservoir of toner, which is picked up by the charged portions of the drum. Finally, the toner is transferred to the paper through a combination of heat and pressure. Laser printers are sometimes called “page printers” because an entire page is transmitted to a drum before the toner is applied.

Thermal Printer

A thermal printer is a printer which heats a selective area of the thermal paper to print its pages. There are two types of thermal printers. There's the thermal wax and the direct thermal printer. A Thermal Transfer printer uses a ribbon with a coating of wax. The ribbons and labels are squeezed together as they pass the thermal print head to form the image. Direct thermal printer is a printer which burns dots into the thermal paper to form words or pictures. Direct thermal is also used by old fax machines. Thermal printers are economic because the only costs to print with these printers are the thermal papers.

Thermal label printers are best for printing bar codes because they produce accurate bar code definitions. Thermal printers produce the exact bar widths that bar code scanning need.

Dot Matrix

A dot matrix printer is also known as a "serial dot matrix printer". It produces characters and illustrations by striking pins against an ink ribbon to print closely spaced dots in the appropriate shapes. This type of printer is relatively expensive, given the fact that it does not produce high-quality output. Unlike laser and ink-jet printers however, it can print to multi-page forms or carbon copies. It is widely used to print multipart forms and address labels. The dot matrix printer uses one or two columns of dot hammers that are moved across the paper. The hammers hit the ribbon into the paper, which causes the ink to be deposited. The more hammers, the higher the resolution. For example, 9-pin heads produce draft quality text, while 24-pin heads produce typewriter quality output. Speeds range from 200 to 400 cps, which is about 90 to 180 lpm.

Dot matrix printers print columns of dots in a serial fashion. The more dot hammers (pins), the better looking the printed results.

Dot matrix printers fitted with a tractor feed are commonly used for printing continuous multipart forms and mailing labels. The tractor feed contains a sprocket that grabs the perforated holes at both sides of the form and pulls it through uniformly.

Plotter
Plotters are large-scale printers that accurately reproduce line drawings. These printers draw the lines and images using a pen and produce continuous lines better than the regular printers which only imitate lines by printing closely-spaced series of dots. Multi-color plotters use different-colored pens for different colors. Plotters are typically used to print on larger sheets of paper such as 17 x 22" (ANSI C), 22 x 34" (ANSI D) or 34 x 44" (ANSI E). Plotters are ideal for engineering applications and technical drawings such as engineering drawings and architectural blueprints where precision is highly recommended.
There are two basic types of plotters: flatbed and drum plotters. Flatbed plotters have a flat surface that is horizontally aligned in which a piece of paper is attached. The paper is stationary as the pens from the printer move across the paper to draw the image. Drum plotters a drum in which the paper rolls on. Some drum plotters are vertically positioned and are known as upright plotters. Drum plotters are more compact and make more noise than the flatbed plotters.
Drum Plotter FlatBed Plotter

Photo Printer

What is a PHOTO PRINTER and what is it for?

A photo printer is a type of printer that specializes in printing photographs. This means that “more attention is paid to color quality, and less to text quality and speed.” They come in different shapes and sizes, and printing quality may also vary. There are some that are very small, made for you to bring along for instant printing. But there are also really big ones for professional printing purposes. Photo printers have special features such as having “big image displays, multiple memory card readers for printing without a PC, 4 x 6 inches photo paper trays, editing functions like red-eye removal, and creative color effects and borders.” They make printing quality photos a lot easier.

There are three categories of photo printers: ink jet photo printers, dedicated photo printers, and professional photo printers. Ink jets function as all-purpose printers. Dedicated photo printers “are typically limited to printing on special-purpose – usually glossy – paper,” and can print only smaller sized output (4 x 6 inches). Professional photo printers “offer at least tabloid-size output (11 x 17 inches).

Advantages of photo printers include high-quality color, direct connectivity to cameras or digital media cards, portability and immediate photos. On the other hand, photo printers are slower, more expensive than normal inkjet printers, and they may not print normal text well.

Portable Printer

What is it?

Portable printers are fairly small in size and are usually equipped with a battery instead of being plugged into a socket. There are a few types of portable printers available on the market: Thermal printer, Thermal transfer printer and Ink-jet printer.

What is it for?

Portable Laptop Printers - Mobile printers for your laptops.

Digital Photo Printer – for printing images. Features included: Card reader, USB ports

Apex Series Printers - designed for today’s mobile workers

Features included: Optional Track Magnetic Card, Wifi and memory of 2mb, 4 MB Flash

The main advantage of having a portable printer is the convenience it gives. Unlike the normal desktop printers, portable printers are lightweight and small in size which allows you to tuck it into your laptop bags. The best thing about this is that you can print your images or files anywhere you want.

Sources: Date Accessed August 6, 2009

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