Head substrate, ink jet head, and ink jet printer

摘要

A head substrate for an ink jet head that discharges ink liquid retained in the ink retaining portion by the ink discharge mechanism in accordance with the printing data inputted from the outside into the data input portion comprises one base substrate having a specific position on the surface for the ink retaining portion to be arranged, and a fuse array storing various readably data freely by selective fusing. This head substrate further comprises a fuse logic circuit for controlling the operation of selective fusing of the fuse array and data reading. Then, the fuse array and the fuse logic circuit are arranged in a position in the direction orthogonal to the surface of the base substrate, but not overlapping with the ink retaining portion. With the fuse array and fuse logic circuit thus structured, this head can be made smaller and lighter in a better productivity as compared with a head for which a ROM chip should be installed separately. Also, it becomes possible to prevent any crack that may occur due to the local heat generated by fusing of the fuse array from being developed into the ink retaining portion for the reliable operation of the head.