Dot Matrix Printer
Original Publication Date: 1980-Jan-01
Included in the Prior Art Database: 2005-Feb-12
A rotating drum 10 causes helical platen 11 to repeatedly scan the horizontal row of print hammer blades 12. Paper 13 and ink ribbon 14 pass between blades 12 and platen 11. Each blade 12 has raised dots 15 on the front edge 16. Actuator means such as a voice coil (not shown) or the like is attached to each blade 12. Recorded dots are formed on paper 13 when one of the raised dots 14 impacts the ribbon 14 and paper 13 against platen 11. The convolutions of platen 11 are pitched so that several blades can operate concurrently without shadow printing. The raised dots 15 are also separated on edge 16 sufficiently to avoid shadow printing. Blades 12 may be horizontally shifted in synchronism with the scan of platen 11 to form dots at predetermined horizontal positions, as dots 15 on edge 16 are horizontally displaced.