Droplet deposition apparatus

Droplet deposition apparatus comprising:

• at least one droplet ejection unit comprising a plurality of fluid channels disposed side by side in a row extending in a first direction, said channels having a length extending in a second direction substantially coplanar with and orthogonal to said first direction, actuator means, and a plurality of nozzles, each nozzle having a nozzle axis extending in a third direction substantially orthogonal to said first and second directions, said actuator means being actuable to eject a droplet of fluid from a fluid channel through a respective nozzle;
• means for conveying droplet fluid to said fluid channels;
• and
• a support member for said at least one droplet ejection unit, said at least one droplet ejection unit being arranged on said support member such that there are n rows of fluid channels extending in said first direction (n being an integral number), said support member having a dimension in said second direction which is substantially equal to n×the length of a fluid channel in said second direction.

Droplet deposition apparatus comprising:

• a support member;
• at least one droplet ejection unit attached to said support member and comprising a plurality of fluid channels disposed side by side in a row;
• and
• a cover member extending over and to the sides of said support member to define with said support member a first conduit extending along said row for conveying fluid to said fluid channels and a second conduit extending along said row for conveying fluid from said fluid channels.

Droplet deposition apparatus comprising:

• at least one droplet ejection unit comprising a plurality of fluid channels disposed side by side in a row, actuator means, drive circuit means for supplying actuating electrical signals to said actuator means, and a plurality of nozzles, said actuator means being actuable to eject a droplet of fluid from a fluid channel through a respective nozzle;
• fluid conveying means for conveying droplet fluid to each of the fluid channels of said at least one droplet ejection unit;
• and
• further coolant conveying means for conveying a coolant fluid, at least one of said drive circuit means and said at least one droplet ejection unit being proximate said coolant conveying means so as to transfer a substantial part of the heat generated during droplet ejection to said coolant fluid.