Determining the cause of printer image artifacts
AssigneeEastman Kodak Company
InventorsThomas Allen Henderson, Richard George Allen
Life of this patent
Estimating the term…
Abstract
A method is provided of determining the cause of artifacts in images produced by an electrophotographic (EP) printer. A reference image is printed and artifacts in it are detected. After printing normal images, a test image is printed and artifacts in it are detected. If a detected artifact in the test image does not correspond to a detected artifact in the reference image, a characteristic frequency spectrum of the artifact in the test image is determined. Run-out on rotatable imaging components is measured, and a characteristic frequency spectrum of each is determined. The test image spectrum is compared to each component spectrum to identify which component is causing the artifact.
Claims7
A method of determining the cause of artifacts in images produced by an electrophotographic (EP) printer, comprising:
- providing the EP printer with:
- a print engine for producing an image on a receiving member, the print engine including a plurality of rotatable imaging components;
- a plurality of runout sensors for measuring the distance between a respective reference point and the surface of the respective rotatable imaging component along a respective reference axis;
- and
- an artifact sensor for detecting one or more artifacts, or the absence of artifacts, in the produced image;
- producing a reference image using the print engine, detecting zero or more artifact(s) in the reference image using the artifact sensor, and storing information identifying the detected artifact(s) in a memory;
- producing one or more image(s) using the print engine;
- producing a test image using the print engine and detecting zero or more artifact(s) in the test image using the artifact sensor;
- determining whether at least one of the detected artifacts in the test image does not correspond to one of the zero or more artifact(s) detected in the reference image using the stored information;
- if one of the artifact(s) does not correspond:
- selecting one of the non-corresponding image artifact(s) in the test image;
- determining a characteristic frequency spectrum of the selected image artifact;
- rotating at least two of the rotatable imaging components and, while each rotatable imaging component is rotating, measuring the respective distances of the component at a plurality of angles of rotation of the imaging component using the respective runout sensor;
- automatically determining a respective characteristic frequency spectrum of each measured imaging component using the corresponding measured distances;
- and
- automatically comparing the characteristic frequency spectrum of the selected image artifact in the test image to the respective characteristic frequency spectra of one or more of the measured imaging component(s) to determine which imaging component(s) are causing the image artifact.
A method of identifying malfunctions in an electrophotographic (EP) printer, comprising:
- providing the EP printer with:
- a print engine for producing an image on a receiving member, the print engine including a plurality of rotatable imaging components;
- and
- a plurality of runout sensors for measuring the distance between a respective reference point and the surface of the respective rotatable imaging component along a respective reference axis;
- a first rotating step of rotating the rotatable imaging components and, while each rotated imaging component is rotating, measuring the respective distances at a plurality of angles of rotation of the imaging component as reference distances using the respective runout sensor;
- for each measured imaging component, storing the measured reference distances or information identifying the reference distances in a memory;
- producing one or more images using the print engine;
- a second rotating step of rotating one or more of the rotatable imaging components and, while each rotated imaging component is rotating, measuring the respective distances at a plurality of angles of rotation of the imaging component as test distances using the respective runout sensor;
- and
- comparing the stored reference distances to the respective test distances and determining that a component whose test distances do not correspond to the respective reference distances is malfunctioning.
Dependencies are inferred from the claim text.