Patent Number: 6,305,775

Title: Ink-jet printing method and apparatus therefor

Abstract: Each nozzle of an ink-jet head has heaters having different heating capacities, and in accordance with the heater driven, a diameter of an ink dot formed by ink which is discharged from the nozzle is changed, thereby printing a large dot or a small dot. When multi-value image data is inputted, the multi-value image data is modulated such that a pixel having high density is printed with both the large dot and small dot. On the basis of the modulated print data, any of the heaters included in each nozzle of the ink-jet head is driven, whereby printing an image having tones based on the multi-value image data.

Inventors: Ohtsuka; Naoji (Yokohama, JP), Takahashi; Kiichiro (Kawasaki, JP), Nishikori; Hitoshi (Inagi, JP), Iwasaki; Osamu (Tokyo, JP)

Assignee: Canon Kabushiki Kaisha

International Classification: B41J 2/21 (20060101); G06K 15/02 (20060101); G06K 15/10 (20060101); B41J 029/38 (); B41J 029/393 (); B41J 002/145 (); B41J 002/14 ()

Expiration Date: 10/23/2018