Method and apparatus for droplet deposition

Abstract

A method for depositing droplets onto a substrate employs an apparatus, such as an inkjet printhead, the apparatus having: an array of channels, acting as fluid chambers,separated by interspersed walls, with each channel communicating with an aperture or nozzle for the release of droplets of a fluid contained within the channel, such as ink. Each of the walls separates two neighbouring channels and is actuable such that, in response to a first voltage, it will deform so as to decrease the volume of one channel and increase the volume of the other channel, and, in response to a second voltage, it will deform so as to cause the opposite effect on the volumes of the neighbouring channels. The method includes the steps of: receiving input data, such as an array of image data pixels; assigning, based on the input data, all the channels within the array as either firing channels or non-firing channels so as to produce groups of one or more contiguous firing channels separated by groups of one or more contiguous non- firing channels; actuating the walls of certain channels so that, for each non-firing chamber, either the walls move with the same sense or they remain stationary, and, for each firing chamber, either the walls move with opposing senses, or one wall is stationary while the other is moved. These actuations result in each of the firing channels releasing at least one droplet of fluid, the resulting droplets forming dots disposed on a straight line on said substrate,for example so as to form a representation of a line of image data pixels. The dots are separated on the line by gaps corresponding to the non-firing channels.

Description

technical field [0001] The present invention relates to a method and apparatus for droplet deposition, and may find particular use in apparatus comprising fluid chambers separated by actuable walls. [0002] In a particular example, the invention relates to an inkjet printer. Background technique [0003] It is known in the art of droplet deposition devices to construct an actuator comprising an array of fluid chambers separated by a plurality of piezoelectric walls. In many such configurations, the walls are actuatable in response to an electrical signal to move toward one of the two chambers defined by each wall; such movement affects the fluid in the two chambers defined by the walls pressure so that the pressure in one chamber increases and the pressure in the other chamber decreases. [0004] A nozzle or orifice is provided in fluid communication with the cavity for causing a volume of fluid to be ejected therefrom. The fluid at the orifice will tend to form a menisc...

AI Technical Summary

Problems solved by technology

[0017] It is noted in this document that this approach provides high productivity but leads to restrictions on the patterns that can be produced

For example, according to this pattern, it is possible to print white-black-white, but not black-white-black

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