(19)
(11) EP 0 361 939 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
25.07.1990 Bulletin 1990/30

(43) Date of publication A2:
04.04.1990 Bulletin 1990/14

(21) Application number: 89309928.3

(22) Date of filing: 29.09.1989
(51) International Patent Classification (IPC)5: G03G 9/10
(84) Designated Contracting States:
CH DE FR GB IT LI NL

(30) Priority: 30.09.1988 JP 248689/88

(71) Applicant: MITA INDUSTRIAL CO., LTD.
Osaka 540 (JP)

(72) Inventors:
  • Fujii, Masanori
    Sakai-shi Osaka (JP)
  • Yamachuchi, Atsushi
    Kobe-shi Hyogo-ken (JP)
  • Komura, Shuji
    Osaka-shi Osaka (JP)
  • Ohgami, Shunsuke
    Hirakata-shi Osaka (JP)

(74) Representative: Opperman, Stuart Richard et al
Haseltine Lake & Co. Hazlitt House 28 Southampton Buildings Chancery Lane
London WC2A 1AT
London WC2A 1AT (GB)


(56) References cited: : 
   
       


    (54) A carrier for a developer


    (57) A carrier for a developer which satisfies the following relation:
    1.7 ≦ X/Y ≦ 3.3
    wherein X is the resistivity (Ω ·cm) of the carrier in a compressed state to which a DC voltage of 1000 V is applied, and Y is the resistivity (Ω ·cm) of the carrier in a state in which the carrier particles are linked together in a chain form in a magnetic field of 1600 gauss to which a DC voltage of 1000 V is applied, thereby constantly providing satisfactory developing characteristics regardless of variations in copying conditions.





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