US Patent 7168792 Ink jet printer head and method of inspecting same

An ink jet printer head including a channel unit having a plurality of ink ejection nozzles arranged in a plurality of arrays and opening in a front surface of the ink jet printer head, a plurality of pressure chambers arranged in a plurality of arrays and communicating with the ink ejection nozzles, respectively, and a plurality of ink channels which deliver at least one kind of ink from at least one ink inlet to the pressure chambers, respectively, and then deliver the at least one kind of ink from the pressure chambers to the ink ejection nozzles, respectively. The channel unit includes a first sheet member having a first planar surface in which a plurality of arrays of recesses defining the plurality of arrays of pressure chambers, respectively, open. The printer head further includes a second sheet member having a second planar surface which is adhered to the first planar surface of the first sheet member so as to close the recesses opening in the first planar surface. At least one of the first sheet member and the second sheet member has at least one inspection-related groove which is located between at least one pair of arrays of recesses of the plurality of arrays of recesses, extends along the at least one pair of arrays of recesses, and communicates with an outside space.