Liquid ejector

#The present application claims priority from Japanese Patent Application No. 2007-339972, which was filed on Dec. 28, 2007, the disclosure of which is herein incorporated by reference in its entirety.

#1. Field of the Invention

#The present invention relates to a liquid ejector configured to eject, from nozzles, liquid in the form of liquid droplets.

#The objects, features, advantages, and technical and industrial significance of the present invention will be better understood by reading the following detailed description of a preferred embodiment of the invention, when considered in connection with the accompanying drawings, in which:

#FIG. 1 is a perspective view of an ink-jet recording head as an embodiment of the present invention;

#FIG. 2 is a plan view of a channel unit of the recording head;

#Hereinafter, there will be described a preferred embodiment of the present invention by reference to the drawings. It is to be understood that the following embodiment is described only by way of example, and the invention may be otherwise embodied with various modifications without departing from the scope and spirit of the invention. The present invention is embodied by a liquid ejector. A recording head 1, as the liquid ejector, ejects ink droplets (i.e., liquid droplets) onto a recording medium (not shown) such as a printer sheet while being moved within a plane parallel to the recording medium, thereby forming an image on the recording medium. The recording head 1 includes a channel unit 2 and a piezoelectric actuator (hereinafter, simply referred to as an “actuator”) 3 superposed on and bonded to a portion of an upper surface of the channel unit 2.

#The channel unit 2 includes nozzles 22 (shown in FIG. 3) opening downward at the lowermost layer of the channel unit 2. The ink droplets are ejected downward from the respective nozzles 22. On an upper surface of the actuator 3, there are provided terminals 45a, 46a respectively connected to common electrodes 45 and individual electrodes 46 (shown in FIG. 3) which will be described below. The terminals 45a, 46a are connected to respective terminals (not shown) provided on a lower surface of a flexible flat cable 4, whereby the actuator 3 and a controller (not shown) are electrically connected to each other. Ink inlet holes 5 are formed in another portion of the upper surface of the channel unit 2, which portion is not covered by the actuator 3. The ink inlet holes 5 are covered by a filter 6 for removing dust or foreign matters mixed in ink.

#As shown in FIG. 3, the channel unit 2 includes, in order from the top, a cavity plate 10, a first supply plate 11, a second supply plate 12, a first manifold plate 13, a second manifold plate 14, a damper plate 15, a cover plate 16, and a nozzle plate 17 which are stacked on and bonded to each other. The nozzle plate 17 is formed of a resin sheet such as polyimide while the other plates 10-16 are each formed of a metal plate such as a 42% nickel alloy steel plate. The plates 10-17 have respective thicknesses each of which falls within a range from about 50 μm to about 150 μm. In each of the plates 10-17, an opening or openings, and/or a recess constituting a channel is or are formed by, e.g., electrolytic etching, laser processing, and plasma jet processing.