US 6,547,367 B1 · Ink jet printing apparatus and a judgement method of an ink ejection state of an ink jet head

Abstract

In an ink jet print head including a plurality of ejection openings arranged therein for ejecting an ink, with the head carrying out printing by moving in a scanning direction relative to a printing medium, an ejection failure is detected promptly and accurately and adhesion of the ink to an ejection face on which the ejection openings are formed is also detected, without affecting print operation sequences. To achieve this, the following operations are performed: While an ink jet print head is being relatively moved in the scanning direction, a light beam is supplied diagonally of an arrangement direction of the plurality of ejection openings and in a direction traversing a trace of the ejected ink. The ink is ejected through the plurality of ejection openings in accordance with predetermined data, and a manner of ink ejection from each of the plurality of ejection openings is detected based on how the ejected ink is blocking the light beam. Based on the detection contents, it is also determined whether or not the ink adheres to the ejection face.

Claims15

Dependent claims

An ink jet printing apparatus for carrying out printing by moving an ink jet head in a scanning direction relative to a printing medium, said ink jet head having a plurality of ejection openings arranged therein for ejecting an ink, said apparatus comprising:

means for emitting a light beam in a direction which is different from an arrangement direction of the plurality of ejection openings and which traverses a trace of the ink ejection through the ejection openings;
means for receiving the emitted light beam;
means for controlling said light beam emitting means to emit the light beam and for controlling said ink jet head to eject ink through the plurality of ejection openings in accordance with predetermined data, while said ink jet head is being relatively moved in the scanning direction between said light beam emitting means and said light beam receiving means;
means for detecting ink ejection states from the plurality of ejection openings based on light beam receiving states at said light beam receiving means;
and
means for judging adhesion of ink to a face of said ink jet head on which the ejection openings are formed, based on the light beam receiving state at said light beam receiving means.

3 more elements

A method of judging an ink ejection state of an ink jet head for carrying out printing by moving in a scanning direction relative to a printing medium, the ink jet head having a plurality of ejection openings arranged therein for ejecting an ink, said method comprising the steps of:

controlling light emitting means to emit a light beam in a direction which is different from an arrangement direction of the plurality of ejection openings and which traverses a trace of the ink ejected through the ejection openings and controlling the ink jet head to eject ink through the plurality of ejection openings in accordance with predetermined data, while the ink jet head is being relatively moved in the scanning direction;
detecting ink ejection states from the plurality of ejection openings based on blocking states of the light beam;
and
judging adhesion of ink to a face of the ink jet head on which the ejection openings are formed, based on the light beam blocking state.

1 more element

Dependencies are inferred from the claim text.

Ink jet printing apparatus and a judgement method of an ink ejection state of an ink jet head

Life of this patent

Ink jet printing apparatus and a judgement method of an ink ejection state of an ink jet head

Life of this patent

Abstract

Claims15