Sharp Kabushiki Kaisha Corporation

Seita Suzuki

Kiyofumi Morimoto

Hiroaki Nakaya

Takanori Kamoto

Masanori Kinomoto

Hiromi Nakatsu

Ichiro Fujii

An image recording apparatus based on a color ink-jet scheme provided with an ink set consisting of one or more than one colors of inks and a black ink and an ink-jet printing unit, wherein the initial contact angles &thgr; of two colors of inks, namely, a color ink and a black ink, fall within the range from 30 to 80&deg;, the contact angle variation Xa of the ink A as obtained by the dynamic liquid absorption measurement after the elapsed time of 1 second falls within the range &minus;70<Xa<&minus;10(&deg;), the dot area ratio Ya of the ink A after the elapsed time of ta seconds-falls in the range 1.5<Ya, the contact angle variation Xb of the ink B as obtained by the dynamic liquid absorption measurement after the elapsed time of 1 second falls within the range &minus;15<Xb<0(&deg;), and the dot area ratio Yb of the ink B after the elapsed time of tb seconds falls within the range 1.0<Yb<1.7, where printing is made first with the ink A and subsequently with the ink B.

Image recording apparatus and recording method based on color ink jet scheme and ink set

Ink for use in ink jet recording

Growing community of inventors

Yamatokoriyama, Japan

Seita Suzuki