| 摘要 |
PURPOSE:To furnish a printing head driving mechanism with a reduced loss time and with an increased printing speed, by providing an electrostrictive element for increasing the amount of flexibility of a leaf spring which is the driving source of a printing head, and by electrifying the element only in printing to keep the leaf spring supporting the head away from a head-driving element so as to increase a force of restoration. CONSTITUTION:An electrostrictive element 5 which is expanded by electrification is attached between a leaf spring 6 supporting a printing head element 1 to be driven and a head-driving element 7. When the element 5 is electrified on the occasion of a printing operation of the head element 1 to be driven, the spring 6 located at a position B is moved instantaneously to a position B''. Therefore a curve (b) of the force of restoration of the spring 6 can be transferred to a curve b' and further to a curve b'' extending beyond a curve (a) of the force of attraction of a permanent magnet 3. Thereby a loss time from an electrification start point A to a printing operation start point B is reduced, a spring charge energy in printing is increased, and acceleration property is improved. The electrification of the element 5 is discontinued simultaneously when the electrification of a coil 2a is discontinued, and thereby an armature 1b is attracted onto the attracting surface 8 of an iron core. |
