Method and apparatus for image squareness correction
AssigneeXerox Corporation
InventorsBrian R. Conrow, David M. Kerxhalli
Life of this patent
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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.
Claims20
A method of correcting output image squareness in a laser printer system having a Raster Output Scanning (ROS) device comprising:
- (a) pivotally mounting said ROS device;
- (b) printing a test pattern including a plurality of predetermined markers;
- (c) measuring a plurality of distances between said markers;
- (d) calculating a skew angle based on the plurality of distances;
- and
- (g) rotating said ROS device by an amount sufficient to correct said skew angle.
In a laser printer system, a skew angle measurement and adjusting system comprising:
- a pivotally mounted ROS device;
- a skew measurement system configured to calculate the skew angle based on a plurality of measured distances between a plurality of printed markers arranged in a predetermined configuration;
- and
- a skew adjustment system configured to adjust the skew angle of the pivotally mounted ROS device based on the calculated skew angle.
A laser printing system comprising:
- (a) a user interface;
- and
- (b) a laser printer including:
- (i) a photoreceptor belt;
- (ii) a pivotally mounted ROS device;
- (iii) an automatic adjustment system for correcting a skew angle of said ROS device;
- (iv) a first program configured to calculate said skew angle from a plurality of distances of a predetermined test pattern printed as an output image, wherein said plurality of distances are received from said user interface;
- and
- (v) a second program configured to adjust said skew angle of said pivotally mounted ROS device utilizing said automatic adjustment system.
Dependencies are inferred from the claim text.