(19)
(11) EP 0 674 993 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
25.06.1997 Bulletin 1997/26

(43) Date of publication A2:
04.10.1995 Bulletin 1995/40

(21) Application number: 95302069.0

(22) Date of filing: 28.03.1995
(51) International Patent Classification (IPC)6: B41J 2/05
(84) Designated Contracting States:
DE FR GB IT

(30) Priority: 31.03.1994 US 221342

(71) Applicant: Hewlett-Packard Company
Palo Alto, California 94304 (US)

(72) Inventors:
  • Miller, Gary L.
    Vancouver, WA 98682 (US)
  • Emad, Pirooz
    Vancouver, WA 98682 (US)
  • Dembiczak, Paul
    Vancouver, WA 98660 (US)
  • Klaus, Richard I.
    E-08190 Sant Cugat Del Vallas (ES)

(74) Representative: Colgan, Stephen James et al
CARPMAELS & RANSFORD 43 Bloomsbury Square
London WC1A 2RA
London WC1A 2RA (GB)

   


(54) System, control circuit and method for electronic correction of pen misalignment in ink jet printers


(57) An ink-jet printing system includes a print head which, due to mechanical misalignment, produces images having a rotational ϑ-Z error if left uncorrected. The printing system has an error correction circuit which causes sets of nozzles within the print head to fire at slightly different times. The result of this is a printed image having one portion offset relative to another portion. The relative offset has the visual effect of reducing the ϑ-Z error. Several techniques for achieving the time spaced nozzle firing and resultant image offset are described. A method for correcting the ϑ-Z error in a printed image is also described.






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