| 摘要 |
PURPOSE:To form an ink drop stably without inadvertently transmitting the vibrations of an ultrasonic wave generating means to a printing head body by providing the head body with the ultrasonic wave generating means through a support member. CONSTITUTION:The diameters of pistons 19, 20 and PZT ceramics 17, 18 are made larger than that of an ink flow path 8. The piston 20 is formed to a two step shape by a base end section 20a having a large diameter and a thin front end section 20b corresponding to the diameter of the ink flow path 8. Consequently, generated ultrasonic vibrations having large amplitude are applied efficiently to ink in the ink flow path 8 by the front end section 20b of the piston 20, and transmitted positively over jet-shaped ink injection from the nozzle 11 of a head body 7. Since an ultrasonic exciter 12 is installed to the head body 7 through a shim 22 constituted so as to damp the vibrations in an ink-jet printing head, the vibrations of the ultrasonic exciter 12 are not transmitted inadvertently over the head body 7, thus stably forming ink drops D. |
