Types of Impact Printers
While many legacy impact printers like daisy wheel and line printers are now obsolete outside niche applications, two longstanding forms retain everyday utility.
1. Dot Matrix Printers
Dot matrix printers contain print heads of thin metal pins that extend to strike an ink ribbon and transfer dots onto paper when needed. Varied pin combinations produce complete characters and graphics to compose printable output augmented with carriage movement.
Key components in a dot matrix printer include:
- Print Head: Houses a vertical column of metal pins that get individually triggered to extend out and print or retract back when not needed for a specific dot position. High quality heads use jeweled tips.
- Inked Ribbon Cartridge: Usually a multipart ribbon cloth saturated in quick drying ink that sits between the print head and paper allowing ink transfer upon pin impact.
- Stepper Motor: Controls horizontal print head motion to facilitate printing full page width rather than just printable column under fixed head. This allows composing the dot matrix output.
- Paper Feed Roller: Feeds continuous stationery paper vertically with perforations that engage the sprocket tractor. Ensures paper alignment.
- Electronics Interface: Inputs digital signals from computer I/O and converts them into electrical commands for print head pin firing order and hammer retractions based on dot pattern requirements.
2. Daisy Wheel Printers
In this type of printer a pre-molded wheel is used which is known as daisy wheel thats why its named as daisy wheel printer. This wheel rotates at fast speed inside printer and prints text on the paper. The daisy wheel contains characters and symbols at the end of each petal or spoke.
Working of daisy wheel printer
- The daisy wheel is made of plastic or metal and contains all alphanumeric characters and punctuation symbols needed for printing on the tips of its petals.
- It spins at very high speed as it prints and must be changed when a different font style is needed.
- As the wheel spins rapidly, a hammer strikes the back of individual petals precisely, causing that character to hit an ink ribbon and be transferred onto the paper with a crisp, clear imprint.
- The imprint is of high quality as full characters are transferred rather than dotted patterns.
- However, the sequential striking of petals as the wheel rotates makes it slower than some other printers.
3. Line Printers
Line printers are high-speed, high-volume impact printers that print complete lines of text at one time using entire sets of characters on spinning drums or bands inside the printer. They focus upon lines that makes them faster.
Working of Line Printers
- Designed for data centers, businesses, institutions needing high throughput printed output
- Print heads consist of spinning metal drums or bands wrapped around pulleys that contain the full set of characters, numbers, and symbols arranged in lines.
- As the drum or band rapidly spins, one line of text, number or symbols gets pressed against the ink ribbon at once through a synchronized striking mechanism.
- This causes the entire line to get printed onto continuous paper fed into the printer.
- Extremely fast as print an entire line together instead of printing character by character.
- Output speed ranges from over 1,000 to nearly 2,000 lines per minute.
4. Band Printers
Band printers are high-speed impact printers that utilize metal bands carrying embossed characters that turn around pulleys within the printer to put marks on paper.
Working of band printers
- Reliable heavy-duty printers built for high duty cycles.
- Use metallic bands that rotate about pulleys powered by motors.
- Bands are embossed with letters, numbers, special symbols in the form of characters.
- The bands move at very fast rate and press an entire row of type against an inked ribbon.
- The ribbon then imprints the ink onto the paper below.
- Band rotation is precisely controlled allowing printing of 2000 lines or more per minute.
- Ideal for printing multi-part stationery as characters strike with strong mechanical impact.
What is an Impact Printer?
Impact printers continue retaining some utility across industries requiring multipart forms, machine-readable output, and longevity in harsh conditions. This article covers the fundamentals of what impact printers have, the types still relevant, and the specifics of working for each.