Liquid-jet head and image forming apparatus

A liquid-jet head comprising:

• a channel plate forming an individual liquid chamber in communication with nozzles configured to eject liquid drops;
• a wall surface member forming a wall surface of the individual liquid chamber;
• and
• a drive unit disposed on the wall surface member side and configured to generate a pressure applied to a drive region inside the individual liquid chamber,
• wherein a fluid resistance part is formed by disposing an island part in a liquid supply channel configured to supply a liquid to the individual liquid channel, and
• the island part includes a gradient part on the channel plate side, at least a part of the gradient part being formed such that the part of the gradient part faces the drive region inside the individual liquid chamber, and
• wherein the channel plate is formed of a silicon substrate, and
• an end part of the island part in a liquid flowing direction includes a (1 1 1) crystal orientation, a first crystal orientation and a second crystal orientation that continue into and are in contact with the (1 1 1) crystal orientation, and a third crystal orientation differing from the (1 1 1) crystal orientation at continues into and is in contact with the first crystal orientation and the second crystal orientation.