| 摘要 |
PURPOSE:To provide a print needle drive device for a printer of which dimension of arrangement direction is small and print cycle is short by providing a magnetic circuit in parallel with a leaf spring, or by providing it separately as No.2 yoke. CONSTITUTION:The density of a magnetic flux to be generated by the magnetic motive force of a permanent magnet 102 passing through the gap between a core 110 and the top end of a leaf spring 104 is raised by closely encircling the outer circumference of an armature 105 with the internal surface of the conical hole 115a of No.2 yoke 115. When a permanent magnet 202 is arranged at the side opposite to the fixed end of a leaf spring 204, the magnet 202 can be arranged in close vicinity to the contact surface of the leaf spring 204. By fixing an armature 205 to the leaf spring 204 so that it pierces through the spring 204, a magnetic circuit can be composed without a leaf spring exist therein, and the leaf spring 204 can be composed with such a material which is nonmagnetic and excellent in spring characteristics. |
