(19)
(11) EP 0 102 038 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
16.05.1984 Bulletin 1984/20

(43) Date of publication A2:
07.03.1984 Bulletin 1984/10

(21) Application number: 83108180

(22) Date of filing: 18.08.1983
(84) Designated Contracting States:
DE FR GB

(30) Priority: 27.08.1982 JP 14880582
27.08.1982 JP 14880782

(71) Applicant: KABUSHIKI KAISHA TOSHIBA
 ()

(72) Inventors:
  • Murakami, Reiji
     ()
  • Karaishi, Toshiyuki
     ()

   


(54) Developing device and developing method


(57) A developing device (18) develops an electrostatic latent image formed on a photosensitive layer of a photosensitive drum (14) by a toner (40) and is provided with a developing roller (36) which rotatably faces the photosensitive layer and is adopted to rotate with the toner (40) thereon forming a toner layer (42), such that the toner (40) is transferred to the photosensitive layer to develop the electrostatic latent image, and a doctor blade (41) which is spaced from the developing roller (36), for regulating the thickness of the toner layer (42) formed on the developing roller (36). The toner (40) consists of an electrically insulating toner whose surface potential (Vt) on the developing roller (36) has polarity opposite to that of changes on the electrostatic latent image and absolute value greater than 20 (volts) and smaller than 90 (volts).






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