1. Technical Field
The present invention relates to a technology for ejecting liquid, such as ink.
2. Related Art
Hitherto, a liquid ejecting head having a configuration in which a plurality of head units that eject liquid, such as ink, through a plurality of nozzles are arranged has been proposed. A configuration in which printing heads are respectively fixed, via a flexible circuit, to inner sides of a plurality of concave portions formed in a plate-shaped supporting body has been disclosed in JP-A-7-251505. A configuration in which a plurality of recording heads are fixed, using a screw, to a plate-shaped module base has been disclosed in JP-A-2005-297554. In addition, a configuration in which a nozzle sheet is bonded to a surface of a plate-shaped frame module having a plurality of opening portions formed therein and head chips are fixed to the nozzle sheet via respective opening portions of the frame module has been disclosed in JP-A-2005-131947.
When the flatness of a plate material having a plurality of head units installed therein is low, in terms of technologies of JP-A-7-251505, JP-A-2005-297554, and JP-A-2005-131947, the distance (hereinafter, referred to as an “ejection distance”) between the respective nozzles of the head unit and a printing medium, such as a printing paper sheet, is different for each head unit. As a result, there is a problem in that the printing quality is reduced. Since, in the technology of JP-A-7-251505, the printing head is fixed, via the flexible circuit, to the inner side of the concave portion of the supporting body, a difference in the ejection distance for each printing head can be apparent. The technology of JP-A-2005-297554 has a problem in that the module base is likely to be deformed (in other words, to be reduced in flatness) by the stress due to the screw for fixing each recording head to the module base. The technology of JP-A-2005-131947 has a problem in that the nozzle sheet in which the plurality of head chips are installed is likely to be deformed because the frame module and the nozzle sheet are subjected to thermocompression bonding such that the frame module pulls the nozzle sheet. Furthermore, there is a problem in that the manufacturing costs are high because the frame module is formed of an alumina ceramic.
When a plurality of head units are installed in a plate material formed of a material having high flatness and rigidity, there is room for a reduction in differences in an ejection distance for each head unit. However, the plate material formed of a material having high flatness and rigidity is likely to be high in manufacturing costs.