US 2008/0259145 A1 · Liquid ejection apparatus and liquid processing method

Abstract

In order to prevent, in an operation for circulating liquid, an ejection port from sucking air or the ejection port from pushing out liquid, the subtank for temporally storing ink to be supplied to the ink jet head includes the air communication passage opened or closed by the air communication valve. The ink jet head is communicated with the subtank by the first passage and the second passage to constitute one circulation passage. In order to circulate the ink in the subtank into the common liquid chamber, the main pump is energized while the air communication valve is being closed. When the circulation operation is stopped, the air communication valve is opened immediately after the stoppage of the main pump, thereby eliminating the differential pressure between the common liquid chamber and the subtank within a short period of time.

Claims9

Dependent claims

A liquid ejection apparatus, comprising:

a head for ejecting liquid from an ejection port;
a subtank for temporarily storing liquid to be supplied to the liquid ejecting head, wherein the subtank includes a space for air;
an air communication valve for opening or closing a passage for communicating air in the subtank;
a circulation flow line for providing communication between the liquid ejecting head and the subtank for circulation, wherein the circulation flow line includes a first passage for supplying liquid from the subtank to the liquid ejection head, and a second passage from the subtank to the liquid ejecting head, and a second passage for returning liquid from the liquid ejecting head to the subtank;
pumping means coupled to the first passage of the circulation flow line for circulating liquid between the liquid ejecting head and the subtank;
and
controlling means for controlling the air communication valve and the pumping means so that the pumping means is driven after closing the air communication valve, so as to circulate liquid, and wherein the controlling means opens the air communication valve to communicate air in the subtank simultaneously with or immediately after the stoppage of the pumping means.

4 more elements

A liquid processing method in a liquid ejection apparatus which includes:

a head for ejecting liquid from an ejection port,
a subtank which includes a space for air and which temporarily stores liquid to be supplied to the liquid ejecting head,
an air communication valve for opening or closing an air communication passage for communicating air in the subtank,
a circulation flow line for providing communication between the liquid ejecting head and the subtank for circulation, wherein the circulation flow line includes a first passage for supplying liquid from the subtank to the liquid ejecting head, and a second passage for returning liquid from the liquid ejecting head to the subtank,
and pumping means coupled to the first passage of the circulation flow line for circulating liquid between the liquid ejecting head and the subtank,
wherein the liquid processing method comprises the steps of:
circulating liquid while driving the pumping means so as to circulate liquid;
and
opening the air communication valve to communicate air in the subtank simultaneously with or immediately after the stoppage of the pumping means.

6 more elements

Dependencies are inferred from the claim text.

Liquid ejection apparatus and liquid processing method

Life of this patent

Liquid ejection apparatus and liquid processing method

Life of this patent

Abstract

Claims9