Patent ID: 6824238
Filing Date: 2004-11-30
Classification: B41J

Abstract:
A liquid jetting apparatus, comprising:a liquid jetting head, including a nozzle orifice, a pressure chamber communicated with the nozzle orifice, and a pressure generating element which varies, the volume of the pressure chamber; and a drive signal generator, which generates a drive signal including a drive pulse, supplied to the pressure generating element, the drive pulse including: a first expanding element, which drives the pressure generating element so as to expand the pressure chamber, so that a meniscus of liquid in the nozzle orifice is pulled toward the pressure chamber as much as possible; a first contracting element, which drives the pressure generating element so as to contract the pressure chamber expanded by the first expanding element, so that a center portion of the meniscus is swelled in an ejecting direction of a liquid drop; a second expanding element, which drives the pressure generating element so as to expand the pressure chamber contracted by the first contracting element, so that a marginal portion of the swelled center portion of the meniscus is pulled toward the pressure chamber; and a second contracting element, which drives the pressure generating element so as to contract the pressure chamber expanded by the second expanding element, so that the meniscus is again urged in the ejecting direction to increase jetting speed of a satellite liquid drop which follows a main liquid drops, wherein a contracted amount of the pressure chamber established by the second contracting element is larger than at least one of a contracted amount of the pressure chamber established by the first contracting element and an expanded amount of the pressure chamber established by the second expanding element; and wherein the contracted amount of the pressure chamber established by the second contracting element is less than an expanded amount of the pressure chamber established by the first expanding element.