(19)
(11) EP 0 836 943 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
26.05.1999 Bulletin 1999/21

(43) Date of publication A2:
22.04.1998 Bulletin 1998/17

(21) Application number: 97118084.9

(22) Date of filing: 17.10.1997
(51) International Patent Classification (IPC)6: B41J 2/06
(84) Designated Contracting States:
AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE
Designated Extension States:
AL LT LV RO SI

(30) Priority: 17.10.1996 JP 274513/96

(71) Applicant: NEC CORPORATION
Tokyo (JP)

(72) Inventors:
  • Shima, Kazuo
    Kashiwazaki-shi, Niigata (JP)
  • Suetsugu, Junichi
    Kashiwazaki-shi, Niigata (JP)
  • Mizoguchi, Tadashi
    Kashiwazaki-shi, Niigata (JP)
  • Minemoto, Hitoshi
    Kashiwazaki-shi, Niigata (JP)
  • Takemoto, Hitoshi
    Kashiwazaki-shi, Niigata (JP)
  • Hagiwara, Yoshihiro
    Kashiwazaki-shi, Niigata (JP)
  • Yakushiji, Toru
    Kashiwazaki-shi, Niigata (JP)

(74) Representative: VOSSIUS & PARTNER 
Siebertstrasse 4
81675 München
81675 München (DE)

   


(54) Electrostatic ink jet printer and head


(57) An ink jet printing head has a protrusion member extending from an electrophoretic electrode in an ink chamber of a base plate to an orifice, and the top end of convex portion thereof protrudes passing through the orifice to the opposite electrode. Accordingly, an ink droplet of an ink always flies from the top end of the protrusion member in the orifice and the flying direction is stabilized. Further, since the top end of the convex portion of the protrusion member projects passing through the orifice, it can be prevented that the ink meniscus retracts into the orifice to form a concave portion after the flying of the ink droplet.
Further, since the protrusion member is secured to the electrophoretic electrode opposed to the orifice, the toner particles in the chamber can be moved along the protrusion member to the orifice when a biased voltage is applied to the electrophoretic electrode, and the degree of concentration of the toner particles to the orifice can be increased.






Search report