Systems and methods for detecting inkjet defects
AssigneeXerox Corporation
InventorsElliott A. Eklund, Jeffrey J. Folkins, David L. Knierim
Life of this patent
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Abstract
A method for testing inkjets for defects in an inkjet device includes determining, based on the likelihood that one or more inkjets are defective, whether to perform an inkjet defect test, The method may also include, identifying, if it is determined to perform an inkjet defect test, which inkjets to test based on properties of the inkjets, the number of identified inkjets being less than a total number of inkjets in the inkjet device; and testing the identified inkjets for defects using an image sensor.
Claims10
A method for testing inkjets for defects in an inkjet device, comprising:
- determining, based on the likelihood that a given inkjet is defective, whether to perform an inkjet defect test;
- identifying which inkjets to test based on (1) the likelihood that a given inkjet is defective and (2) a predicted failure rate for each of the inkjets, the number of identified inkjets being less than the total number of inkjets in the inkjet device;
- marking a test image on an intermediate substrate using only the identified inkjets, if it is determined to perform an inkjet defect test;
- evaluating the test image for defects by using an image sensor;
- tracking characteristics of each inkjet related to failure of that inkjet;
- and
- quantifying the tracked characteristics,
- wherein the step of identifying which inkjets to test based on a predicted failure rate for each of the inkjets in the inkjet device comprises:
- comparing the quantified characteristics of each inkjet in the inkjet device with a predefined limit;
- identifying an inkjet for defect testing if that inkjet's quantified characteristics is over the predefined limit;
- and
- adjusting the quantified characteristics for each inkjet in the inkjet device, if that inkjet has a history of failure, based on a position of that inkjet within a predetermined distance relative to an edge of the sheet media.
A system for testing inkjets for defects in an inkjet device, comprising:
- an image sensor that is configured to detect at least one of the presence, intensity, and location of marking material jetted on an intermediate substrate by the inkjets of the inkjet device;
- and
- a controller that:
- determines, based on the likelihood that a given inkjet is defective, whether to perform an inkjet defect test,
- identifies which inkjets to test based on (1) the likelihood that a given inkjet is defective and (2) a predicted failure rate for each of the inkjets in the inkjet device, the number of identified inkjets being less than total number of inkjets in the inkjet device;
- marks a test image on an intermediate substrate using only the identified inkjets, if it is determined to perform an inkjet defect test;
- and
- evaluates the test image for defects by using the image sensor;
- tracks characteristics of each inkjet related to failure of that inkjet;
- quantifies the tracked characteristics,
- wherein the step of identifying which inkjets to test based on a predicted failure rate for each of the inkjets in the inkjet device comprises:
- comparing the quantified characteristics of each inkjet in the inkjet device with a predefined limit;
- identifying an inkjet for defect testing if that inkjet's quantified characteristics is over the predefined limit;
- and
- adjusting the quantified characteristics for each inkjet in the inkjet device, if that inkjet has a history of failure, based on a position of that inkjet within a predetermined distance relative to an edge of the sheet media.
Dependencies are inferred from the claim text.