US 6,641,246 B2 · Detection of non-operating nozzle by light beam passing through aperture

Abstract

The object is to provide a technique whereby a non-operating nozzle can be detected with higher accuracy. The present invention resides in a printer for printing images by ejecting ink droplets from a plurality of nozzles, wherein an optical path in which light from a light-emitting element 40a for emitting light is focused by a first focusing element 41, allowed to pass through a focusing aperture 43a that is substantially circular and smaller than the area illuminate by the light, and transmitted through the focusing aperture 43a to a light-receiving element 40b for receiving light is laid out according to a configuration in which an intersection is formed with the path described by the ink droplets ejected by the nozzles. The light-emitting element 40a is energized and caused to emit light. The nozzles are actuated and ink droplets are ejected in the direction of a space in which the intensity of light is greater than a prescribed level and which is part of the optical path between the focusing aperture 43a and the light-receiving element 40b. A non-operating nozzle is then detected based on the fact that the light received by the light-receiving element 40b is blocked by the ink droplets thus ejected.

Claims26

Dependent claims

A printer for printing images by ejecting ink droplets from a plurality of nozzles, comprising:

a print head having a plurality of nozzles;
and
a sensor including a light-emitting element configured to emit detection light which has a substantially circular cross-section and a light-receiving element configured to receive the detection light, and configured to inspect operation of a nozzle by determining whether the detection light has been blocked by the ink droplets ejected by the nozzle,
the sensor further comprising:
a first condensing element configured to condense the detection light;
and
an apertured element having a substantially circular aperture for the detection light, the aperture having a size of a same order as the cross-section of the detection light,
wherein the detection light intersects an ejecting path of the ink droplets at an exit side of the apertured element and the first condensing element.

5 more elements

A method for detecting a non-operating nozzle in a printer for printing images by ejecting ink droplets from a plurality of nozzles, comprising the steps of:

(a) providing a light-emitting element configured to emit detection light which has a substantially circular cross-section, a first condensing element configured to condense the detection light, an apertured element having a substantially circular aperture for the detection light, and a light-receiving element configured to receive the detection light after the detection light intersects a path of the ink droplets ejected by a nozzle, the aperture having a size of a same order as the cross-section of the detection light;
(b) emitting the detection light from the light-emitting element;
(c) ejecting ink droplets from a nozzle;
and
(d) detecting a non-operating nozzle by determining whether the detection light received by the light-receiving element has been blocked by the ink droplets.

2 more elements

Dependencies are inferred from the claim text.

Detection of non-operating nozzle by light beam passing through aperture

Life of this patent

Detection of non-operating nozzle by light beam passing through aperture

Life of this patent

Abstract

Claims26