Impact Printers

What is an Impact Printer?

An Impact Printer is a printer that prints by mechanical impacts. Examples include Dot Matrix, Plotter and Thermal printers. These are three common and popular impact printers.

Dot Matrix

-How it works? A 9 or 24 pin head which the computer controls, the pin head runs back and forth and strikes a ribbon which is soaked in ink against a page repeatedly as the page scrolls through. It is much like the print mechanism on a typewriter and generally prints one line at a time.

Advantages -

-They are Cheap to buy and run and have one of the lowest printing costs per page
-Dot matrix printers can print on multi-part stationery and make several copies and can also make carbon copies of documents.
-They are able to use continuous paper rather than requiring individual sheets, making them useful for data logging.

Disadvantages -

-The output is of low quality
-They are noisy due to the pins striking the ribbon to the paper.
-They can only print lower-resolution graphics, with limited color performance, limited quality, and lower speeds compared to non-impact printers.

-They are prone to paper jams

Usage - They are commonly used in cash registers for receipts, ATM, and many other point-of-sales terminals. They are still used to print multi-part stationery, for example at bank tellers.


Plotter Printers
A plotter printer is a computer printing device for printing vector graphics.

How does it work?
Plotters print by moving a pen or other instrument across the surface of a piece of paper. The plotters use one or more heads to draw graphics or text and the printer head is attached to a horizontal bar and can be moved horizontally or vertically and draws lines and curves.
-. Pen plotters can draw complex line art including text.

-because they are a vector graphics printer, meaning they can only print lines and minimum curves, they are great for printing blueprints and maps.

-Plotters are restricted to line art, rather than raster graphics as with other printers

-They are very expensive so big businesses are usually the only ones that use them.

-They are slow because of the mechanical movement of the pens

-They print poor quality ordinary photographs


Thermal Printers

How does it work- They work similarly to Dot Matrix printers, however the pins make a mark by burning the image into the paper rather than using ink. They require a special type of paper called thermochromic paper, or thermal paper as it is commonly known.

-Thermal printers print faster and quieter than dot matrix printers.
-They are also smaller, lighter and consume less power, making them ideal for portable and retail applications.
-For some applications they can be more economical since their only consumable is the paper itself.

- They have low-capacity cartridges which can have a higher per-page cost.

Usage-Thermal printers have many uses which include:
- Filling station pumps
- Information kiosks,
- Point of sale systems,
- Voucher printers in slot machines, a
- For recording live rhythm strips on hospital cardiac monitors.
- Fax Machines

Sample Exam Question:
Discuss the advantages and disadvantages of 3 Impact Printers. (9marks)