(19)
(11) EP 0 774 356 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
01.10.1997 Bulletin 1997/40

(43) Date of publication A2:
21.05.1997 Bulletin 1997/21

(21) Application number: 96118185.6

(22) Date of filing: 13.11.1996
(51) International Patent Classification (IPC)6: B41J 2/175
(84) Designated Contracting States:
DE FR GB

(30) Priority: 14.11.1995 JP 295467/95

(71) Applicant: FUJI XEROX CO., LTD.
Minato-ku, Tokyo (JP)

(72) Inventors:
  • Isozaki, Jun, c/o Fuji Xerox Co., Ltd.
    Ebina-shi, Kanagawa (JP)
  • Fujimura, Yoshihiko, c/o Fuji Xerox Co., Ltd.
    Ebina-shi, Kanagawa (JP)
  • Ogasawara, Fumihiko, c/o Fuji Xerox Co., Ltd.
    Ebina-shi, Kanagawa (JP)
  • Tomikawa, Ichiro, c/o Fuji Xerox Co., Ltd.
    Ebina-shi, Kanagawa (JP)

(74) Representative: Boeters, Hans Dietrich, Dr. et al
Patentanwälte Boeters & Bauer, Bereiteranger 15
81541 München
81541 München (DE)

   


(54) Ink jet print head, ink jet printer and method for maintaining ink jet print head


(57) In an ink supply member including an ink supply passage for supplying ink to a common reservoir , a plurality of gas hold portions are formed to be respectively in communication with only the common reservoir and are capable of holding gas therein. Pressure caused by air bubbles generated in heat elements not only causes ink to be jetted out from nozzles but also is transmitted to the common reservoir, so that the internal pressure of the common reservoir is caused to vary. Also, when ink is refilled, the internal pressure of the common reservoir is caused to vary reversely. These pressure variations are absorbed by the expansion/compression of gas held within the gas hold portions, thereby being able to restrict the pressure variations within the common reservoir as well as prevent generation of undesirable phenomena such as unprinted areas, density variations, and the like.






Search report