13.3.4 Impact Printers

Learn about impact printers.

Impact printers are a legacy type of printer, coming out in the 70s and 80s. They're still in active production, and new models are still being released. They work similarly to old typewriters, by physically striking the printhead to the print surface (the sheet of paper), leaving behind an inked impression. They are among the loudest type of printers, and they are by no means the fastest.

On an impact printer, an electromagnetic pulse enables a small hammer to make the strike. Whenever the printer receives data for a print job, the logic board generates the list of electric impulses, and converts the list to physical movements to strike the printhead. There are two different types of printheads for the impact printer.

Character Style

The printheads on character-style printers have fully formed characters. They're also interchangeable, so printing in different fonts is supported.

On daisy-wheel printers, there's a wheel, and each spoke on the wheel has a character on the end (like a typewriter). The electric impulses from the printer spin the wheel, rotating the character into the correct position for the hammer to strike the spoke. It hits the ribbon, which hits the paper, and the character is printed on the page. Ball-style printheads work similarly.

Dot-Matrix Style

Dot-matrix printers also have a thing for being the synonym for impact-printing in general. They became popular because they were cheap, faster than daisy-wheel printers, and can print both text and some graphics. Dots are printed when a hammer strikes the matrix printhead with the pin grid. Different characters and symbols can be printed using different pin combinations, and are printed one grid/row at a time. The electric impulses calculated by the printer define which pins to strike when and where.

Depending on quality, a dot-matrix printer can have from 9 to 48 pins for a print quality ranging from 100 to 400 DPI.

Line-Matrix Printers

A line matrix printer is a dot matrix printer on steroids.

hey, they said it. wasn't me ¯\_(ツ)_/¯

Line-matrix printers print an entire line at a time. The printhead resembles a comb with it's 132 pins, and each pin has their own designated hammer to be able to print at any time without waiting for the others to be printed. This allows the printhead the move less and the printer can print faster. Line-matrix printers are the fast of all the impact printers, with speeds of up to 3,000 lines/min.

These printers are designed to be fast, reliable, and resistant to rough handling in industrial environments. They've truly earned their name: the work horse of large computer installations. They're used to produce invoices, bank statements, product shipment & transportation documents, and compliance labels.

They are often referred to in modern operating systems with the abbreviation LPT.

Special Applications

Impact printers have many special applications that they work well for. They are widely considered the best technology for printing multipart forms with carbon or carbonless paper. Because they physically strike the surface of the print material, they add security for print-through envelopes used for confidential forms (e.g. pay slips, tax returns). They're also ideal for datalogging since they can use continuous scrolls of paper.

They are also used to print different types of media, such as:

• heat-sensitive labels
• overside media
• cardstock
• cloth
• barcodes (unmatched in this category)

They are also widely used because of their long lifespan relative to their maintenance cost. The average lifespan of a dot-matrix printer is 7-10 years. They have the lowest printing cost in terms of energy usage, cost per page, and consumables i'm guessing repair. They deliver unmatched uptime and reliability, and they require significantly less maintenance than modern (often delicate) printers.

For quantity over quality situations, impact printers are the better choice over laser printers because they can print pages faster than them (most of the time).

Maintenance (Raw Lesson Content)

Replace the printhead.

• Printheads are usually modular and easy to change.
• The printhead may become hot due to the striking action. Use caution and allow it to cool before handling.
• Look for a lever or release button, remove, replace, and click to lock in.

Make sure to get the correct replacement part for the make & model of the printer.

Replace the ribbon.

• It is important to get the correct replacement ribbon for the make/model of printer.
• Newer printers may use a self-contained cartridge for one-time use. Click to remove and replace.
• For older printers that may use a double-reel system, rethread the new ribbon the same way as the old ribbon.
• To replace a reusable fabric ribbon cartridge, rethread the new ribbon the same as old.

Make sure to only replace the ribbon when the print is too light or when the cartridge is exhausted.

Replace the paper.

• Replace continuous paper by inserting and aligning sprockets with holes on paper.
• Be sure the supply of continuous paper can feed freely so it doesn't pull, tear, or cause a jam.
• For preprinted continuous forms, align the fields properly and run a test page to avoid continuous errors.

Run a test page to check alignment and print quality after replacing the paper.

#XIII

#Aplus