Droplet Deposition Apparatus

A droplet deposition apparatus, such as an inkjet printhead, is disclosed. The apparatus includes an array of fluid chambers, where each chamber has a nozzle and a piezoelectric actuator element that causes droplets to be released on-demand from the nozzle in an ejection direction. The array of chambers extends in an array direction, which is perpendicular to the ejection direction. The apparatus also includes a common inlet manifold, which supplies fluid to the array of chambers, and may also include a common outlet manifold, which receives fluid from the array of chambers; both the inlet manifold and, where present, the outlet manifold are elongate in the array direction and extend the length of the array of chambers. The apparatus also includes a flow restrictor passage, which extends the length of the array of chambers in the array direction. This may either: connect the inlet manifold to the array of chambers so that during use fluid can flow along the length of the common inlet manifold, through the flow restrictor passage, then through said array of fluid chambers, and then into and along the length of said common outlet manifold; or, in situations where a common outlet manifold is provided, it may connect the array of chambers to the outlet manifold so that during use fluid can flow along the length of the common inlet manifold, through the array of fluid chambers, then through the first flow restrictor passage, and then into and along the length of the common outlet manifold. When a cross-section taken perpendicular to the array direction is viewed, the flow restrictor, and the manifold to which it is connected, are shaped such that the flow restrictor appears as a narrow, elongate passage linking that manifold to the chambers. The flow restrictor passage presents sufficient impedance to fluid flow such that, in use, fluid within it that is adjacent to the array of chambers is directed generally perpendicular to the array direction for substantially all of the chambers in the array.