Printing head for a dot printer

摘要

A printer head for mosaic printing having a plurality of needles positioned on a straight line each being selectively driven towards a paper through an ink ribbon has been found. The printer head comprises of a cylindrical permanent magnet, a first yoke covering the bottom of the permanent magnet, a plurality of electromagnets each positioned on a circle on the first yoke with the predetermined angle intervals, a disk shaped spring having an outer ring and a plurality of projections towards the center of the disk, a plurality of armatures each attached to the related projection of the disk spring, a plurality of print needles each attached to the related projection of the disk spring so that each of the needles has the perpendicular component to the disk spring plane. A ring shaped spacer is positioned between the disk spring and the cylindrical permanent magnet, a second yoke for providing a magnetic flux path is positioned between the permanent magnet and each of the electromagnets, and a guideframe having a thin linear slit for arranging the top of said needles and covering the needles is provided.