Method and apparatus for image squareness correction
US7071956B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 7, 2002 |
| Grant date | Jul 4, 2006 |
| Priority date | — |
| Expiry date | Oct 6, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N2201/04755
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method of correcting output image squareness in a laser printer system having a Raster Output Scanning (ROS) device with a pivotal mounting. The method includes printing a test pattern that includes a plurality of markers printed in a predetermined geometric arrangement and calculating a skew angle based on the measured distances, preferably using the Law of Cosines. The ROS device is then automatically rotated by an amount sufficient to correct the skew angle. The ROS rotation is performed automatically by an adjustment system connected to the ROS. The method optionally includes a scanner for scanning the test pattern image and making the measurements automatically via a program configured to analyze the scanned image.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.