Reversal developing system

(19)

(11)

EP 0 849 644 A3

(12)	EUROPEAN PATENT APPLICATION

(88)	Date of publication A3:
	01.07.1998 Bulletin 1998/27

(43)	Date of publication A2:
	24.06.1998 Bulletin 1998/26

(21)	Application number: 97203909.3

(22)	Date of filing: 12.12.1997

(51)	International Patent Classification (IPC)⁶: G03G 15/09

(84)	Designated Contracting States:
	AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE
	Designated Extension States:
	AL LT LV MK RO SI

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Priority:

20.12.1996 EP 96203585

(71)	Applicant: Océ-Nederland B.V.
	5914 CC Venlo (NL)

(72)	Inventors:
	Mooren, Gerardus Johannes Catharina 5913 WJ Venlo (NL) Valk, Johannes 2911 EG Nieuwerkerk a/d IJssel (NL)

(74)	Representative: Hanneman, Henri W., Dr.
	Océ-Technologies B.V. Patents & Information St. Urbanusweg 43 P.O. Box 101 5900 MA Venlo 5900 MA Venlo (NL)

(54)	Reversal developing system

(57) A reversal developing system for developing a charge pattern with electrically charged toner powder, comprising:

an image forming medium (10) carrying said charge pattern,
a movable developing member (12) transporting said charged toner powder to a developing zone (14) adjacent to said image forming medium (10),
means for applying a reversal development voltage to said movable developing member (12) so as to cause said charged toner powder to deposit on virtually uncharged areas of said image forming medium (10),
a cleaning electrode (42) disposed at a distance from the surface of the developing member (12) and having an applied voltage of such a magnitude that toner particles which adhere to the surface of the developing member (12) are released therefrom under the influence of the electric field existing in the space between the developing member (12) and the cleaning electrode (42).