Patent ID: 6554400
Filing Date: 2003-04-29
Classification: B41J

Abstract:
A nozzle plate for an ink jet head provided with nozzle orifices through which ink is to be ejected,wherein the nozzle orifices are formed in the nozzle plate by an excimer laser device with a working lens which has a numerical aperture (NA) set to 0.13 or more and 0.35 or less, wherein the range of the numerical aperture is determined based on size of a round portion produced around the nozzle orifice and a focal depth of an optical system used in the excimer laser device, and wherein the value 0.13 is selected so that an amount of the round portion becomes lower than a predetermined amount and approximately corresponds to 2 &mgr;m size of the round portion, and the value 0.35 is selected so that the nozzle plate and the working lens are easily positioned when the nozzle orifices are formed by the excimer laser device.