(19)
(11) EP 0 399 478 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
04.12.1991 Bulletin 1991/49

(43) Date of publication A2:
28.11.1990 Bulletin 1990/48

(21) Application number: 90109729.5

(22) Date of filing: 22.05.1990
(51) International Patent Classification (IPC)5: G03G 15/01, G03G 13/01
(84) Designated Contracting States:
GB

(30) Priority: 26.05.1989 US 358101
26.05.1989 US 358916
26.05.1989 US 358918

(71) Applicant: EASTMAN KODAK COMPANY
Rochester, New York 14650-2201 (US)

(72) Inventors:
  • Steele, Lawrence Charles, c/o Eastman Kodak Co.
    Rochester, New York 14650 (US)
  • Rook, Kenneth Edward, c/o Eastman Kodak Co.
    Rochester, New York 14650 (US)
  • Santilli, Domenic, c/o Eastman Kodak Co.
    Rochester, New York 14650 (US)
  • Kamp, Dennis Reed, c/o Eastman Kodak Co.
    Rochester, New York 14650 (US)

(74) Representative: Blickle, K. Werner, Dipl.-Ing. et al
KODAK AKTIENGESELLSCHAFT Patentabteilung
70323 Stuttgart
70323 Stuttgart (DE)


(56) References cited: : 
   
       


    (54) Method and apparatus for improving a multi-color electrophotographic image by buffing


    (57) An improvement in the method and apparatus for producing a multi-color electrophotographic image wherein an electrophotographic medium (16) is mounted on a carrier (12) therefor and is translated over a predetermined path (14) so that the medium (16) is first charged, then exposed to a first light-borne image and then toned. Thus, the unexposed portions of the image bearing charged region of the medium (16) are toned, preferably by a liquid toner, to produce a first color visiblc image. The carrier (12) is then returned to the first position to repeat the foregoing steps to charge the medium and to expose it to a second light-borne image and to tone the second image with a second toning element to produce a second color visible image on the same sheet of medium (16). The improvement comprises means (31) for buffing the surface of the first toned image with a relatively coarse, stiff, and rough fibrous brush member after the first toning step and prior to the second charging step to smooth the previously toned image to prevent color contamination by subsequent imaging cycles. One of the images formed is a cyan image formed with an improved self-fixing, liquid electrographic developer comprising a volatile, electrically insulating liquid carrier and, dispersed in said carrier, (i) toner particles comprising a polymeric binder, cyan pigment and a dispersing agent whereby the cyan image does not flake off or smear during the buffing step.







    Search report