US 8,985,736 B2Granted

Image forming apparatus having ink jet head and method for performing maintenance of the same

AssigneeToshiba Tec Kabushiki Kaisha

InventorsHideyuki Akaba, Hideaki Nishida

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Abstract

An image forming apparatus includes an ink jet head, having a pressure chamber, a flow path and a nozzle, which ejects ink in the pressure chamber through the nozzle, a first tank connected to the flow path, a supply unit which supplies ink in the first tank to the pressure chamber through the flow path, a second tank connected to the flow path, a discharge unit which moves ink in the pressure chamber to the second tank through the flow path, and a control section which activates the supply unit and the discharge unit so that ink in the pressure chamber is discharged to the second tank by the discharge unit, ink in the first tank is charged to the pressure chamber by the supply unit and the liquid surface of ink supplied to the pressure chamber is projected from the nozzle.

Claims16

Dependent claims

An image forming apparatus comprising:

an ink jet head, including a pressure chamber to which ink is charged, a flow path fluidly communicating with the pressure chamber and a nozzle open to the pressure chamber, which is configured to eject ink in the pressure chamber from the nozzle;
a first tank, connected to the flow path of the head, which is configured to store ink;
a supply unit configured to supply the ink in the first tank to the pressure chamber of the head through the flow path of the head;
a second tank, connected to the flow path of the head, which is configured to store ink;
a tank moving mechanism configured to vertically move the second tank to a position lower than that of the head so that the ink in the pressure chamber of the head is discharged to the second tank through the flow path of the head;
and
a control section configured to activate the supply unit and the tank moving mechanism so that the ink in the pressure chamber is discharged to the second tank by the tank moving mechanism, the ink in the first tank is charged to the pressure chamber by the supply unit and the liquid surface of the ink supplied to the pressure chamber is projected from the nozzle of the head to discharge a caked ink in the ink in the nozzle of the head.

4 more elements

A method for performing maintenance of an image forming apparatus, comprising an ink jet head, having a pressure chamber to which ink is charged, a flow path fluidly communicating with the pressure chamber and a nozzle open to the pressure chamber, which is configured to eject ink in the pressure chamber from the nozzle, a first tank, connected to the flow path of the head, which is configured to store ink, a supply unit configured to supply the ink in the first tank to the pressure chamber of the head through the flow path of the head, a second tank, connected to the flow path of the head, which is configured to store ink, tank moving mechanism configured to vertically move the second tank, and a control section configured to activate the supply unit and the tank moving mechanism, which includes:

vertically moving the second tank to a position lower than that of the head by the tank moving mechanism to discharge the ink in the pressure chamber of the head to the second tank through the flow path of the head;
charging the ink in the first tank to the pressure chamber by the supply unit;
and
projecting the liquid surface of the ink supplied to the pressure chamber from the nozzle of the head to discharge a caked ink in the ink in the nozzle of the head.

1 more element

Dependencies are inferred from the claim text.