Wire dot printer head and wire dot printer using the same

A wire dot printer, comprising:

• a sheet transferring passage for guiding a sheet;
• transferring rollers for transferring the sheet in the sheet transferring passage;
• a platen arranged along the sheet transferring passage;
• a wire dot printer head;
• comprising
• a yoke;
• a plurality of cores arranged in an annular form on the yoke;
• a plurality of coils combined with the cores so as to fit the cores;
• a plurality of armatures supported so as to be raised or lowered in respect to the cores;
• a plurality of wires supported at the free ends of the armatures in such a way that they may be driven and displaced;
• and
• an extremity end guide having a plurality of guide holes for independently and slidably supporting the extremity ends of the wires and arranging them,
• wherein when the moving direction of the wire dot printer head is applied as a main scanning direction, the guide holes of the extremity end guide are arranged along an arc curved only in one direction of the sub-scanning direction so as to cause the arrangement positions in the main scanning direction to be made different;
• wherein the wire dot printer head is opposite to the platen through the sheet transferring passage and movably held in a width direction of the sheet transferring passage;
• and
• means for applying voltage to coils driving respective wire while changing timing in response to the arrangement positions of the extremity ends of the wires in the main scanning direction.