Patent ID: 6179410
Filing Date: 2001-01-30
Classification: B41J

Abstract:
A printer comprising:a printing head comprising a pressure chamber into which a discharge medium is introduced, the printer head further comprising a nozzle forming member, the nozzle forming member comprising a surface layer in which a nozzle is formed, and a substrate disposed in which a pressure chamber is formed, the surface layer overlying the substrate, the nozzle being in fluid communication with the pressure chamber, the discharge medium being discharged through a nozzle opening disposed in the surface layer,the pressure chamber being defined by a recess disposed in the substrate, a diaphragm being connected to the substrate opposite the surface layer so that the diaphragm covers the recess, the pressure chamber extending between the nozzle and a discharge supply passage, the discharge supply passage being disposed between a discharge supply port and the pressure chamber, the discharge supply port being narrower than the pressure chamber thereby limiting backflow from the pressure chamber through the discharge supply passage and to the discharge supply port, the nozzle being narrower than the pressure chamber,the surface layer being disposed around the nozzle opening and comprising a polyimide polymer having the following formula: ##STR13##wherein k, l, m and n are integers, the substrate comprising a material selected from the group consisting of polysulfane and polyethersulfane.