Patent attributes
Techniques for calibrating a scanner mounted on a scanning carriage of an image forming device. In one embodiment, a method of calibrating an optical sensor of a color image forming device includes positioning a prefabricated optical sensor target at the service area of the image forming device, the target including a plurality of target patches of predetermined different colors, moving the carriage to the service area, acquiring one or more images of the plurality of target patches, and using the one or more images to perform a plurality of calibrations of the optical sensor. In another embodiment, a method of measuring a reference position of a carriage mounted sensor array for an image forming device includes moving the carriage to a service area, generating a light beam from a carriage-mounted light source at a position adjacent an end of a sensor array, the light beam at an acute angle relative to an array axis, reflecting the beam from a reference target mounted in the service area at a known position, acquiring an image of the reflected beam by the sensor array, and using the location of a high intensity area of the image to determine the reference position of the optical sensor.