Patent ID: 8599435
Filing Date: 2013-12-03
Classification: G03G

Abstract:
1. A method for estimating photoreceptor motion quality in a printer, the method comprising: exposing, within a printer having an exposure module and a moving photoreceptor, a first pattern and a second pattern onto the photoreceptor, the first pattern comprising a first set of image components that are transverse to a motion of the photoreceptor and the second pattern comprising a second set of image components that are transverse to the motion of the photoreceptor, the exposing of the first pattern starting at a first start time and the exposing of the second pattern starting at a second start time subsequent to the exposing of the first pattern; storing the first start time and the second start time; creating, in response to the exposing, a first image capturing the first pattern and a second image capturing the second pattern determining, based upon respective distances between adjacent image components captured within the first image, a first set of photoreceptor velocity values indicating respective velocities of the photoreceptor between exposing each image component within the first image; determining, based upon respective distances between adjacent image components captured within the second image, a second set of photoreceptor velocity values indicating respective velocities of the photoreceptor between exposing each image component within the second image; combining, based on the first start time and the second start time, the first set of photoreceptor velocity values and the second set of photoreceptor velocity values into a phase coherent composite set of photoreceptor velocity values that indicate photoreceptor velocity during exposing the first pattern and the second pattern, determining, based on a frequency transform of the phase coherent composite set of photoreceptor velocity values, respective frequency components for the velocity of the photoreceptor during exposing of the first pattern and the second pattern; and outputting data derived from the respective frequency components.