| 摘要 |
PURPOSE:To prevent the thermal deformation of a nozzle and pierce the nozzle without any pitch error by repeating a process of successively irradiating less than several shots of pulselike laser beams to the plural ejection pot parts of the nozzle. CONSTITUTION:The pulselike laser beam 3 from a laser beam generator 7 is advanced strighforward and is irradiated by optical apparatus 9, 10 to the ejection port parts in the right side direction of the plural ejection port parts provided circumferentially to a nozzle 1. For the ejection port parts in the left side direction of the nozzle 1, a plane reflecting mirror 11 for inversion is provided between the generator 7 and a direction changer 8, and further the laser beam is entered from the left side of the changer 8 past plane mirrors 12, 12', 12'', after which the beams are irradiated by the optical apparatus 9, 10. At this time, the process of successively irradiating each of less than several shots of the pulselike laser beam from the generator 7 to the circumferentially provided ejection port parts of the nozzle 1 is repeated desired times, whereby through-holes are formed in the ejection port parts. |
