(19)
(11) EP 0 502 720 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
09.12.1992 Bulletin 1992/50

(43) Date of publication A2:
09.09.1992 Bulletin 1992/37

(21) Application number: 92301870.9

(22) Date of filing: 04.03.1992
(51) International Patent Classification (IPC)5: B41J 2/295
(84) Designated Contracting States:
DE GB

(30) Priority: 04.03.1991 JP 19196/91

(71) Applicant: BROTHER KOGYO KABUSHIKI KAISHA
Nagoya-shi, Aichi-ken 467 (JP)

(72) Inventor:
  • Ikezaki, Yoshiyuki, c/o Brother Kogyo K. K.
    Nagayo-shi, Aichi-ken (JP)

(74) Representative: Senior, Alan Murray et al
J.A. KEMP & CO., 14 South Square, Gray's Inn
London WC1R 5LX
London WC1R 5LX (GB)


(56) References cited: : 
   
       


    (54) Dot matrix impact print head device


    (57) A dot matrix impact print head device having a plurality of print units. In each of the print units, an end of a support leaf spring (24) supported on a print head body and an end of a drive leaf spring(25) whose another end is connected to a piezoelectric element (5) are joined parallel to each other by a rigid joint (26). The joint is fixed to a proximal end of an arm (22).When the support and drive leaf springs are resiliently deformed, the arm is angularly moved about a pivotal center axis (31) defined by these leaf springs. A line (32) interconnecting the axis (31) and the proximal end of the print wire (7a) extends substantially perpendicularly across the direction of back-and-forth movement of the print wire. When a piezo-electric element (5) is displaced in response to the application of a voltage, an arm (32) is angularly moved through the two leaf springs (25, 26) to move a print wire (7) mounted on the distal end of the arm (22) back and forth.






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