US 6,309,050 B1Granted

Ink jet recording apparatus having deflection means for deflecting droplets of ink emitted through a nozzle

AssigneeMatsushita Electric Industrial Co., Ltd.

InventorsKoji Ikeda, Atsushi Sogami, Akira Fukano

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Abstract

A nozzle of an ink jet head is formed such that a droplet of ink is emitted in a direction nonparallel to a virtual plane formed by a scanning direction X and an electric field direction Z. A voltage is applied between a nozzle plate and a facing electrode for creating an electric field. First and second ink droplets are emitted from the same nozzle during one print cycle. The first ink droplet is emitted in an uncharged state in order not to be deflected by the electric field. On the other hand, the second ink droplet is emitted in a charged state in order to be deflected by the electric field. Because of the difference in deflection amount, the landing positions of the first and second ink droplets are varied, whereby dot density can be improved to be twice as great as nozzle density.

Claims25

Dependent claims

An ink jet recording apparatus comprising:

an ink jet head having a nozzle through which a droplet of ink is emitted,
relative movement means for causing said ink jet head and a recording medium placed face to face with said nozzle to relatively move in a scanning direction, with a specified clearance maintained between said nozzle and said recording medium,
a facing electrode disposed face to face with said nozzle in such a way as to put said recording medium between said nozzle and said facing electrode,
voltage applying means for electrifying an ink droplet emitted from said nozzle and for applying a voltage between said nozzle and said facing electrode thereby to create an electric field,
said nozzle is formed in such a way as to emit an ink droplet in a direction nonparallel with a virtual plane formed by said scanning direction and the direction of said electric field, and
landing position varying means which is capable of varying a landing position of an ink droplet emitted from said nozzle in a direction normal to said scanning direction on said recording medium, by deflecting a flying direction of the ink droplet by an electric field created between the nozzle and the facing electrode.

3 more elements

Dependencies are inferred from the claim text.