| 摘要 |
PURPOSE:To make the injecting direction of ink drop uniform and to prevent occurrence of foam, by projecting the end face of a head containing rows of nozzles formed with accumulated nozzles from the head body and making the width of projecting face at most about two times of the cross-section of each nozzle and symmetrical with respect to the nozzle rows. CONSTITUTION:The surface containing nozzles 21 projects by a width of (b1+b2+b3) to form a projecting face 10, where b1, b3 are shorter than half of the nozzle width b2. When a head is driven, the end face is wetted by ink, but since a projecting section 11 has a narrow width, ink adhered to the projecting section 11 forms a thin film and excessive ink flows into a recess 12. The end face is formed from hydrophylic material in order to promote dispersion of ink. When an ink drop is injected, surface tension is balanced between an ink drop 27 and ink around the nozzle 21 if the projection 11 is symmetrical with respect to the nozzle 21, thereby injecting direction of ink drop is made uniform thus retarding entrapment of foam into the nozzle. |
