Ink jet print head having members with different coefficients of thermal expansion

An ink jet print head comprising:

• a metallic nozzle member having a plurality of nozzles through which fine particles of ink are jetted, and a first and a second opposite major surface;
• a ceramic ink pump member having a first and a second opposite major surface, said ceramic pump member being superposed on and bonded to said nozzle member, the first opposite major surfaces of the nozzle member and a ceramic ink pump member being bonded together, said ink pump member having a plurality of ink chambers formed behind respective nozzles of said nozzle member, said ink pump member including a plurality of piezoelectric/electrostrictive elements each disposed on a portion of said ink pump member opposite a respective ink chamber, for deforming said portion so as to change a pressure of the respective ink chamber, whereby the ink supplied to the ink chamber is jetted through the corresponding one of said nozzles;
• and
• coefficient of thermal expansion adjusting means for reducing a stress which is applied to said ink pump member due to a difference between a coefficient of thermal expansion of said nozzle member and a coefficient of thermal expansion of said ink pump member, said coefficient of thermal expansion adjusting means comprising an adjusting member that is superposed on and bonded to the second opposite major surface of said nozzle member which is remote from said ink pump member, the coefficient of thermal expansion of said adjusting member being smaller than the coefficient of thermal expansion of said nozzle member.

An ink jet print head comprising:

• a metallic nozzle member having a plurality of nozzles through which fine particles of ink are jetted, and a first and a second opposite major surface;
• a ceramic ink pump member having a first and a second opposite major surface, said ceramic pump member being superposed on and bonded to said nozzle member, the first opposite major surfaces of the nozzle member and the ceramic ink pump member being bonded together, said ink pump member having a plurality of ink chambers formed behind respective nozzles of said nozzle member, said ink pump member including a plurality of piezoelectric/electrostrictive elements each disposed on and directly bonded to a portion of said ink pump member opposite a respective ink chamber, for deforming said portion so as to change a pressure of the respective ink chamber, whereby the ink supplied to the ink chamber is jetted through the corresponding one of said nozzles;
• and
• coefficient of thermal expansion adjusting means for reducing a stress which is applied to said ink pump member due to a difference between a coefficient of thermal expansion of said nozzle member and a coefficient of thermal expansion of said ink pump member, said coefficient of thermal expansion adjusting means comprising an adjusting member that is superposed on and bonded to the second opposite major surface of said ink pump member which is remote from said nozzle member.