(19)
(11) EP 0 867 284 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
25.08.1999 Bulletin 1999/34

(43) Date of publication A2:
30.09.1998 Bulletin 1998/40

(21) Application number: 98200819.5

(22) Date of filing: 16.03.1998
(51) International Patent Classification (IPC)6: B41J 2/05, B41J 2/14, B41J 2/205
(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

(30) Priority: 26.03.1997 US 826357

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

(72) Inventor:
  • Wen, Yin, c/o Eastman Kodak Company
    Rochester, New York 14650-2201 (US)

(74) Representative: Lewandowsky, Klaus, Dipl.-Ing. et al
Kodak Aktiengesellschaft, Patentabteilung
70323 Stuttgart
70323 Stuttgart (DE)

   


(54) Imaging apparatus and method adapted to control ink droplet volume and void formation


(57) Imaging apparatus and method adapted to control ink droplet volume and void formation. The apparatus (10) includes an ink jet print head (45) having a nozzle (110) for ejecting an ink droplet (150) therefrom. A heater element (130) is in heat transfer communication with the ink droplet for variably supplying heat energy to the ink droplet, so that the volume of the ink droplet is controlled as the heat energy is variably supplied to the ink droplet. A controller (40) is connected to the heater element for variably controlling the heat energy supplied to the ink droplet. The controller variably controls the heat energy by variably controlling a plurality of voltage pulses sequentially supplied to the heater element. Moreover, in order to reduce the potential for void formation in the ink droplet, the pulses are spaced-apart by a predetermined delay interval. Suitable control of ink droplet volume and delay interval between pulses results in uniform print density and "gray-scaling" of each dot or pixel in the output image and also precludes void formation.






Search report