Method and apparatus for eliminating distortion via overscanned illumination for optical printers and the like having high gamma photosensitive recording media and high addressability
AssigneeXerox Corporation
InventorDouglas N. Curry
Life of this patent
Estimating the term…
Abstract
A method and apparatus is described for eliminating banding, misregistration and bowing by controlling a composite light intensity profile and phase shifting of a spatial location at which the composite light intensity profile crosses a xerographic threshold in a two dimensional high addressability printer operating in an overscan mode. The contrast, pitch grating and phase shifting are dependent on at least one of a predetermined amount of overlap, an exposure profile and an intensity value of each of the plurality of laser beam spots formed on the photosensitive medium of a two dimensional high addressability printer.
Claims3
A method for eliminating banding distortions in an image printed by printing apparatus, comprising the steps of:
- determining a desired process direction velocity for a photoreceptor device of the printing apparatus;
- determining a desired scanning velocity for a scanning device of the printing apparatus;
- determining an actual velocity for at least one of the photoreceptor device and the scanning device;
- determining an error velocity for each determined actual velocity;
- determining an error distance from the determined error velocities and a scan interval;
- and
- adjusting a count value of a modulo counter of the printing apparatus based on the determined error distance.
A method for avoiding misregistration in a multicolor printing apparatus, comprising the steps of:
- determining an interval between a page sync signal and a start of scan signal;
- determining an error distance from the determined interval and an addressability value;
- and
- adjusting a count value of a modulo counter of the printing, apparatus based on the determined error distance.
A method for correcting for bowing distortions in a printing apparatus;
- comprising the steps of:
- determining a bowing amount and a bowing direction;
- determining an addressability value;
- determining correction intervals based on the bowing amount and the addressability value;
- selectively incrementing and decrementing a count value of a modulo counter of the printing apparatus each correction interval based on the bowing direction.
Dependencies are inferred from the claim text.