| 摘要 |
PURPOSE:To enable follow-up and response of the titled printing head at far higher speed, by a method wherein an auxiliary coil, which is independent of a coil of an electromagnet and owning a magnetic path jointly with the coil, is provided and the auxiliary coil is electrified so that a magnetic flux becomes applicable in the direction negating a residual magnetic flux in the inside of a magnetic circuit after suspension of electrification to the electromagnet. CONSTITUTION:A printing wire is held on the tip of an armature 2. An auxiliary coil 16 which is common to a plurality of pieces of electromagnet is provided on the external circumference of a core frame 4 of a printing head. Then the auxiliary coil 16 is electrified so that a magnetic flux is made to generate in the direction negating a residual magnetic flux in the inside of an electromagnetic circuit after suspension of electrification to a coil 10. Arrows A, B show respectively a direction of the magnetic flux resulting from the electrification of the coil 10 and the direction of the magnetic flux resulting from electrification of the auxiliary coil 16. Then a reduction ratio of the magnetic flux in the inside of the magnetic circuit can be improved by electrifying the auxiliary coil 16, through which return action of the armature is made smooth and follow-up and response at far higher speed are made possible. |
