Ink jet recording apparatus

An inkjet recording apparatus comprising:

• a conveyance unit which has a cylindrical conveyance drum on an outer circumferential curved surface of which is mounted a recording medium, and conveys the recording medium by rotation of the conveyance drum around a cylindrical shaft;
• a head unit which has a nozzle ejecting ink onto the recording medium which is conveyed;
• an attachment member whose relative position to the cylindrical shaft is fixed and to which the head unit is attached such that the outer circumferential curved surface of the conveyance drum faces an opening across a predetermined relative distance, the opening of the nozzle being formed on a nozzle surface in the head unit;
• a fixing member which fixes a fixing portion in the head unit to the attachment member, the fixing portion being positioned between a center of gravity of the head unit and the cylindrical shaft in a direction which is in a horizontal plane and perpendicular to the cylindrical shaft;
• and
• a support member which applies force to the head unit fixed to the attachment member and supports the head unit, the force being in a direction to disturb rotation of the head unit due to gravity,
• wherein the nozzle includes multiple nozzles, and the nozzle surface is provided with openings of the respective multiple nozzles over a predetermined recording width in a cylindrical shaft direction along the cylindrical shaft,
• wherein the fixing member includes a first fixing member and a second fixing member and the fixing portion includes a first fixing portion and a second fixing portion,
• wherein the first fixing member fixes the first fixing portion in the head unit to the attachment member, the first fixing portion being positioned on one side of an arrangement range of the multiple nozzles in the cylindrical shaft direction,
• wherein the second fixing member fixes the second fixing portion in the head unit to the attachment member, the second fixing portion being positioned on another side of the arrangement range of the multiple nozzles in the cylindrical shaft direction, and
• wherein the support member applies force in the cylindrical shaft direction to a position of the head unit between the first fixing portion and the second fixing portion and supports the head unit.

An inkjet recording apparatus comprising:

• a conveyance unit which has a cylindrical conveyance drum on an outer circumferential curved surface of which is mounted a recording medium, and conveys the recording medium by rotation of the conveyance drum around a cylindrical shaft;
• a head unit which has a nozzle ejecting ink onto the recording medium which is conveyed;
• an attachment member whose relative position to the cylindrical shaft is fixed and to which the head unit is attached such that the outer circumferential curved surface of the conveyance drum faces an opening across a predetermined relative distance, the opening of the nozzle being formed on a nozzle surface in the head unit;
• a fixing member which fixes a fixing portion in the head unit to the attachment member, the fixing portion being positioned between a center of gravity of the head unit and the cylindrical shaft in a direction which is in a horizontal plane and perpendicular to the cylindrical shaft;
• and
• a support member which applies force to the head unit fixed to the attachment member and supports the head unit, the force being in a direction to disturb rotation of the head unit due to gravity,
• wherein the head unit comprises:
• a recording head which has the nozzle surface;
• and
• a substrate to which the recording head is fixed,
• wherein the recording head is fixed to the substrate in a state where the nozzle surface is exposed from one surface of the substrate,
• wherein the fixing member fixes the fixing portion provided on the one surface of the substrate to the attachment member,
• wherein the head unit comprises a case provided on a surface of the substrate which is opposite to the one surface, and
• wherein the support member applies force to the case and supports the head unit.

An inkjet recording apparatus comprising:

• a conveyance unit which has a cylindrical conveyance drum on an outer circumferential curved surface of which is mounted a recording medium, and conveys the recording medium by rotation of the conveyance drum around a cylindrical shaft;
• a head unit which has a nozzle electing ink onto the recording medium which is conveyed;
• an attachment member whose relative position to the cylindrical shaft is fixed and to which the head unit is attached such that the outer circumferential curved surface of the conveyance drum faces an opening across a predetermined relative distance, the opening of the nozzle being formed on a nozzle surface in the head unit;
• a fixing member which fixes a fixing portion in the head unit to the attachment member, the fixing portion being positioned between a center of gravity of the head unit and the cylindrical shaft in a direction which is in a horizontal plane and perpendicular to the cylindrical shaft;
• and
• a support member which applies force to the head unit fixed to the attachment member and supports the head unit, the force being in a direction to disturb rotation of the head unit due to gravity,
• wherein the support member has a first portion and a second portion, a relative position of the first portion with respect to the cylindrical shaft being fixed, and the second portion being different from the first portion and fixed to the head unit, and
• wherein the support member supports the head unit by tensile stress generated between the first portion and the second portion.