(19)
(11) EP 0 546 559 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
27.07.1994 Bulletin 1994/30

(43) Date of publication A2:
16.06.1993 Bulletin 1993/24

(21) Application number: 92121101.7

(22) Date of filing: 10.12.1992
(51) International Patent Classification (IPC)5: G03G 15/09, H01F 7/02
(84) Designated Contracting States:
DE FR GB IT

(30) Priority: 11.12.1991 JP 109879/91
20.12.1991 JP 111634/91
08.01.1992 JP 4091/92

(71) Applicant: KANEGAFUCHI KAGAKU KOGYO KABUSHIKI KAISHA
Kita-ku Osaka-shi Osaka 530 (JP)

(72) Inventors:
  • Sakata, Yoshio, c/o Kanegafuchi Kagaku Kogyo K.K.
    Otsu-shi, Shiga 520-01 (JP)
  • Kakehashi, Yasushi, c/o Kanegafuchi Kagaku Kogyo
    Otsu-shi, Shiga 520-01 (JP)
  • Hirai, Masatoshi, c/o Kanegafuchi Kagaku Kogyo K.K
    Otsu-shi, Shiga 520-01 (JP)

(74) Representative: VOSSIUS & PARTNER 
Postfach 86 07 67
81634 München
81634 München (DE)


(56) References cited: : 
   
       


    (54) Magnet roll


    (57) The substantially cylindrical plastic bonded magnet is provided with plural magnetic poles which are formed on the magnet by the focus orientation method in the presence of magnetic field. The maximum outer diameter of the magnet is below 30 mm, and flexural strength thereof is above 1200 kgf/cm2. In addition, both end portions of the magnet in the longitudinal direction are formed by only one cutting processing. Both end proportions of the magnet are used as fitting portions in order to fit the magnet directly to the body of a developing unit. Said magnet roll comprises only a few parts and can be produced at low costs.






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