Modular printhead assembly
View Patent ↗A modular printhead assembly includes a substrate member. A plurality of printhead modules is fastened to the substrate member. Each printhead module includes a layered structure through which at least differently colored inks are fed. The layered structure has at least a lower layer, a middle layer and a top layer, with the lower layer defining a number of channels in fluid communication with respective ink supplies, the middle layer defining a number of openings in fluid communication with the channels, and the top layer defining a number of channels on a bottom side and openings in a top side in fluid communication with the channels. A micro-electromechanical printhead integrated circuit is mounted on the layered structure. The printhead integrated circuit has a plurality of micro-electromechanical nozzles arranged on a silicon layer. The silicon layer defines a plurality of ink channels for feeding ink to the nozzles, the openings in the top layer being substantially aligned with the ink channels. An ink supply is arranged on the substrate member and is in fluid communication with the channels in the bottom layer through openings in the substrate member.
1. A modular printhead assembly which comprises
a substrate member;
a plurality of printhead modules fastened to the substrate member, each printhead module comprising
a layered structure through which at least differently colored inks are fed, the layered structure comprising at least a lower layer, a middle layer and a top layer, with the lower layer defining a number of channels in fluid communication with respective ink supplies, the middle layer defining a number of openings in fluid communication with the channels, and the top layer defining a number of channels on a bottom side and openings in a top side in fluid communication with the channels;
a micro-electromechanical printhead integrated circuit mounted on the layered structure, the printhead integrated circuit comprising a plurality of micro-electromechanical nozzles arranged on a silicon layer, the silicon layer defining a plurality of ink channels for feeding ink to the nozzles, the openings in the top layer being substantially aligned with the ink channels; and
an ink supply arranged on the substrate member and in fluid communication with the channels in the bottom layer through openings in the substrate member.
2. A printhead assembly as claimed in claim 1 , in which the holes and channels of each layered structure together define an air passage to facilitate cleaning of the nozzles.
3. A printhead assembly as claimed in claim 1 , in which each printhead module has a flexible printed circuit board bonded to the top layer and connected to the nozzles with wires.
4. A printhead assembly as claimed in claim 1 , in which the top layer of each printhead module comprises a sheet of stainless steel.
5. A printhead assembly as claimed in claim 1 , in which the substrate member is in the form of a channel with the printhead modules fastened to an outer surface of a floor of the channel and the ink supply extending along and within the channel.
6. A printhead assembly as claimed in claim 5 , in which the ink supply comprises a flexible ink hose.
7. A printhead assembly as claimed in claim 6 , in which the flexible ink hose and the floor of the channel have corresponding holes to permit ink to flow from the hose to the channels of the bottom layer of each printhead module.