Patent ID: 6204869
Filing Date: 2001-03-20
Classification: G03G

Abstract:
In a printing machine having a movable imaging member, a projecting system for modulating a beam and projecting an image into the movable imaging member, a developer for application of developer material to the image projected onto the movable imaging member for transfer of the image to a print medium sheet, a method for controlling exposure of a test patch on the movable imaging member comprising:a) providing a time-keeping device with the time-keeping device including a variable value which is either incrementable or decrementable;b) detecting a signal indicating that the movable imaging member is positioned relative to the writing exposure beam in a selected orientation, wherein the movable imaging member passes by the beam at a selected speed;c) providing a reference value;d) in response to said detecting of (b), modulating the beam, relative to the movable imaging member, so as to expose a portion for the test patch;e) concurrent with said modulating of (d), incrementing or decrementing the variable value of the time keeping device; andf) repeating said modulating of (d) until the value of the variable value is about equal to the reference value and the test patch is exposed.