公开(公告)号：JPH02179762A

公开(公告)日：1990-07-12

申请号：JP24239889

申请日：1989-09-20

Applicant: IBM

Inventor： MAIKERU FUIRITSUPU GORUDOOSUKI ,  KUNO TEIJI ,  JIYON PIITAA KARIDESU ,  SHIBUYA HIROMI ,  UEDA OSAMU

IPC: B41J2/28 ,  B41J9/38 ,  H01F7/14

Abstract: PURPOSE: To make small an actuator by neutralizing a magnetic flux passing a magnetic pole of a permanent magnet for holding an armature by a magnetic flux generated from an electromagnetic coil while being energized thereby biasing the armature. CONSTITUTION: When a coil 20 is excited, an electromagnetic flux almost equal to a magnetic field of a permanent magnet 18 in the opposite direction to that of the magnetic field of the permanent magnet 18 is generated. As a result, the coil 20 almost neutralizes the magnetic field of the magnet 18 holding an armature 28. The armature 28 comes not to be held by the magnetic field of the permanent magnet 18. The energy stored in a spring 32 and the armature 28 separates the armature 28 from a stator 10, which is converted to a kinetic energy for printing. After printing is finished, the excitation of the coil 20 is stopped, and the armature 28 is caught again by the magnetic flux of the permanent magnet 18 and held at a non-print position on magnetic poles 14, 16. When the current of the coil 20 is inverted in direction, the armature 28 is temporarily attracted to the magnet 18, so that the magnet 18 stably holds the armature 28. A package is thus made small and consumption power is reduced.