Patent ID: 8596757

Claim:
A liquid jet head, comprising: an actuator substrate comprising: a plurality of grooves, which are elongated in a direction from a front end of a substrate surface to a rear end thereof, and arranged in a direction intersecting the direction from the front end to the rear end while being spaced apart from one another through an intermediation of partition walls; drive electrodes, which are formed on side surfaces of each of the partition walls; and extension electrodes, which are electrically connected to the drive electrodes and formed on the substrate surface in the vicinity of the rear end; a cover plate, which is bonded to the substrate surface and closes upper openings of the plurality of grooves to form a plurality of channels; and a flexible substrate, which is bonded to the substrate surface in the vicinity of the rear end, and comprises wiring electrodes electrically connected to the extension electrodes, wherein the plurality of channels comprise: a discharge channel for discharging liquid; and a dummy channel that does not discharge the liquid, the discharge channel and the dummy channel being arranged alternately with each other, wherein the plurality of grooves comprise a groove constituting the dummy channel, which extends to the rear end of the actuator substrate, wherein the extension electrodes comprise: an individual extension electrode, which is formed on the substrate surface in the vicinity of the rear end between two dummy channels adjacent to both sides of the discharge channel, and electrically connected to drive electrodes formed on side surfaces of the two dummy channels on the discharge channel side; and a common extension electrode, which is formed on the substrate surface in the vicinity of the rear end and closer to the front end than the individual extension electrode, and electrically connected to drive electrodes formed on two side surfaces of the discharge channel, wherein the wiring electrodes comprise: a common wiring electrode, which electrically connects the common extension electrode corresponding to the discharge channel, and another common extension electrode corresponding to another discharge channel; and a plurality of individual wiring electrodes, which are electrically and individually connected to the individual extension electrode corresponding to the discharge channel and another individual extension electrode corresponding to the another discharge channel, and wherein, in a common wiring intersection region in which the common wiring electrode intersects the drive electrodes, upper end portions of drive electrodes formed on side surfaces of the groove constituting the dummy channel are formed deeper in a depth direction of the groove than the substrate surface.