Lecture Notes: Dot Matrix Printers

Overview of Dot Matrix Printers

• Impact Printer: Uses impact to press against a ribbon, creating marks on paper
• Print Mechanism: Pins in the matrix press into the ribbon, leaving dots that form characters
• Output: Consists of small dots; zooming in on characters like '7' reveals dot matrix pattern

Advantages

• Multiple Copies: Can use carbon paper to print multiple pages simultaneously
• Low Cost: Only requires ribbon ink, making it cost-effective per page

Disadvantages

• Noise: Impact process generates significant noise, often louder than other printers
• Resolution: Not suitable for high-resolution, graphical output; best for text and numbers

Printing Mechanism

• Components: Paper, ribbon, and printhead
  • Printhead Movement: Moves back and forth to create output using pins
  • Heat Dissipation: Contains a heatsink to dissipate heat during printing
• Pins: 24 pins within the matrix, width of a character
• Ink Transfer: Pins press ink from ribbon onto paper
• Ribbon: Made of fabric, long and constantly cycled, easy to replace
  • Compatibility: Each ribbon is proprietary to a specific printer model

Paper Handling

• Tractor Feed: Pulls paper through printer using holes on sides
  • Paper Type: Often perforated for easy separation
  • Loading Paper: Guides used to align and secure paper
• Paper Feed Button: Press to pull paper and prepare for printing
• Perforated Paper: Long, folded paper that can be separated into individual sheets
• Green Bar Paper: Common with mainframes, features tractor feed, 11x14 inches size