Patent ID: 6199970
Filing Date: 2001-03-13
Classification: B41J

Abstract:
A droplet emitter array comprising:a) a first substrate having a thermal expansion coefficient being so arranged and constructed to provide a two-dimensional array of focussed acoustic waves, the array of focussed acoustic waves having at least two rows extending in a row direction and at least two columns extending in a column direction wherein the row direction is transverse to the column direction, and a length and a width wherein the length is greater than the width,b) a second substrate, having a thermal expansion coefficient, being spaced from the first substrate, the second substrate having a two-dimensional array of apertures, the array of apertures having at least two rows extending in a row direction and at least two columns extending in a column direction wherein the row direction is transverse to the column direction and, the second substrate being arrange relative to the first substrate such that each aperture may receive focussed acoustic waves from the first substrate wherein the space between the first and second substrates forms at least a portion of a liquid flow chamber having an inlet and an outlet which have been adapted to receive a flow of a liquid such that a free surface of the liquid is formed by each of the apertures in the second substrate, the focussed acoustic waves received by each aperture are focussed substantially at the free surface of the liquid formed in the aperture, and the flow of liquid flows sequentially in through the inlet, past substantially all of the array of apertures, and out through the outlet wherein at least a portion of the flow of liquid flows laminarly in substantially the width direction.