CompTIA A+ 220-1201 (3.8 - Impact Printers)

Dot-matrix (impact) printers

• Print head with a small matrix of pins

- Presses against a ribbon to make a mark on paper

• Good for carbon/multiple copies

• Low cost per page

• NOISY

• Poor graphics

• Relatively niche use cases

Dot-matrix printer head

• Moves back and forth

- Pins hit ribbon and paper

• One matrix - Must move across the page to print

Printer ribbon

• Fabric

- One long ribbon - Never ending circle

• Easy to replace - Once single unit

• Proprietary size - Specific to printer model

Tractor feed

• Paper pulled through with holes on the side of the paper

- Instead of using friction

• Continuous paper feed - Perforations between pages

• Holes have to line up perfectly

- Tractor paper can be perforated to remove holes

Multipart paper

• Carbonless copying

- Multiple copies of a single form in a single pass

• Impact with the top sheet is duplicated on pages

underneath

- Micro-encapsulated ink on the back of the first sheet

- Clay surface reaction on the top of the second sheet

• Impact activates these inks, dyes, and clay

- Can be a mild irritation with certain chemical

combinations

• Easier and less expensive to just print another copy

- May be difficult to find multipart paper in use

- Or dot-matrix printers