There are provided a substrate on which a first integrated circuit, a first transistor, a second integrated circuit, and a second transistor are disposed; a heat sink fixed to the substrate; a first heat conductive elastic body which is in contact with the heat sink and the first integrated circuit; a second heat conductive elastic body which is in contact with the heat sink and the first transistor; a third heat conductive elastic body which is in contact with the heat sink and the second integrated circuit; and a fourth heat conductive elastic body which is in contact with the heat sink and the second transistor, the heat sink has a first recess portion positioned between the first heat conductive elastic body and the second heat conductive elastic body, and a second recess portion positioned between the third heat conductive elastic body and the fourth heat conductive elastic body.

There are provided a substrate on which a first integrated circuit, a first transistor, a second integrated circuit, and a second transistor are disposed; a heat sink fixed to the substrate; the substrate has a first fixing reference hole and a second fixing reference hole, the heat sink has a first fixing reference pin and a second fixing reference pin which are inserted into the first fixing reference hole and the second fixing reference hole, and the first integrated circuit, the second integrated circuit, the first transistor, and the second transistor are positioned between the first fixing reference hole and the second fixing reference hole.

The communication plate has a first layer that defines a wall surface of the communication flow channel, a second layer stacked on a side of the first layer opposite to the wall surface, and a third layer stacked on a side of the second layer opposite to the first layer, and the thermal expansion coefficient of the second layer is smaller than the thermal expansion coefficient of the first layer and is smaller than the thermal expansion coefficient of the third layer.

A liquid ejection head including a recording element substrate for ejecting liquid supported by a support member with an adhesive layer provided between the recording element substrate and the support member. A terminal is provided at an end portion of the recording element substrate with a sealing member covering the end portion of the recording element substrate including the terminal. The sealing member is in contact with a side surface of the end portion and an end surface of the adhesive layer. The adhesive layer comprises includes a first adhesive portion and a second adhesive portion positioned between the first adhesive portion and the sealing member. Rigidity of the second adhesive portion is less than the rigidity of the sealing member and less than the rigidity of the first adhesive portion.

A liquid ejection head includes: head units arranged in a first direction; first individual heat dissipators each corresponding to one of the head units and disposed on a first side of the head unit in a second direction; and a first common heat dissipator disposed on the first side of the head units in the second direction. The first common heat dissipator extends in the first direction and shared among the head units. Each head unit includes: a unit body including an actuator; and a first driver integrated circuit disposed on the first side of the unit body in the second direction. Each of the first individual heat dissipators is disposed between the first driver integrated circuit and the first common heat dissipator of the head unit so as to be in thermal contact with the first driver integrated circuit and the first common heat dissipator.

Misalignment of printing positions is reduced in a print head that circulates an ink between a printing apparatus and the print head in a case where the misalignment is apt to change dynamically along with heat deformation. To this end, printing element substrates in the print head are adjusted to a target temperature and then a liquid is circulated through the print element substrates. After thermal expansion of the print head reaches a steady state, an amount of misalignment of printing positions in a direction of conveyance of the print head is obtained by using a test pattern printed by using printing elements. Further, a correction value for correcting the misalignment of the printing positions is set based on the obtained amount of misalignment of the printing positions.

Misalignment of printing positions between print heads associated with thermal expansion is reduced without increasing a data processing load. To this end, printing element substrates in a reference head and an adjustment target head are adjusted to a target temperature, and a liquid is circulated through the print element substrates. After thermal expansion of the reference head and the adjustment target head reaches a steady state, a first printing region being a printing region of the reference head and a second printing region being a printing region of the adjustment target head in a longitudinal direction are obtained from an image printed by using all printing elements. Then, used regions to be used for actual printing are set among the printing elements arranged on the reference head and the adjustment target head based on the first printing region and the second printing region.

Provided is an ink-jet head including: a back end portion; a front end portion which ejects the ink; a heating plate which is arranged between the back end portion and the front end portion, and which heats the back end portion and the front end portion; and a temperature detection device which is provided on the heating plate, and which outputs a value in accordance with a temperature of the front end portion, the temperature detection device being held in direct contact with the front end portion.

An ink heating device, which is incorporated in an inkjet printing apparatus, includes: a planar heating member bonded in a state where one surface of the planar heating member is thermally bonded to an outer surface of an ink tank storing ink; an elastic member, having a heat insulation property, is provided on the other surface of the planar heating member and presses the planar heating member against the ink tank; and a hardware processor that performs heating control on the planar heating member in a stepwise manner according to a stop time of a main body of the printing apparatus at a time of starting the main body of the printing apparatus.

A flow channel member includes a first flow channel member non-transmissive of ultraviolet light and absorbent of laser light, a second flow channel member non-transmissive of ultraviolet light and absorbent of laser light, the second flow channel member being stacked on the first flow channel member to define a flow channel for liquid to flow between the second flow channel member and the first flow channel member, and a third flow channel member transmissive of laser light, the third flow channel member being fixed to the first flow channel member and the second flow channel member in such a manner as to close a gap between the first flow channel member and the second flow channel member.