US 2003/0156181 A1 · Technique for printing a color image

Abstract

A technique for optimizing or enhancing color images. Embodiments are disclosed for creating an enhanced color image, including the enhancement of perceived color uniformity. In a “dot-on-dot” registration scheme for producing color images, the dots need to be precisely superimposed on each other to provide optimum or enhanced images. The dot-on-dot registration produced by a single head thermal printer is generally acceptable, but a single head machine is very slow because multiple passes (reciprocation) are required to lay down multiple colors of dots. In a much faster multi-head or tandem thermal imaging system a serious problem of dot misalignment may cause moire patterns or other visual artifacts in the color images produced by dot patterns. A solution to this problem is disclosed herein which intentionally misregisters superimposed dots in a novel and particular manner to achieve image optimization. In a particular embodiment a first thermal print head has a first number of thermal elements energized at a first rate and a second thermal print head has a second number of thermal elements energized at a second rate. The numbers of thermal elements and rates of energization are selected to cause intentional misregistration at a high spatial frequency which is unnoticeable to the naked eye of a viewer of the image, thereby masking any unintentional mechanical misalignment of the print heads while maintaining imperceptible the intentional misregistraton of the solution to the problem.

Claims92

Dependent claims

A system for creating an enhanced color image on a movable planar surface using a plurality of arrays of dots, said surface moving in a first direction parallel to said surface, said system comprising:

first means for creating a first one of said arrays in a first color as a first colored array on said surface, said dots forming said first colored array being spaced at first predetermined distances from each other;
second means for creating a second one of said arrays in a second color as a second colored array generally superimposed on said first colored array, said dots forming said second colored array being spaced at second predetermined distances from each other;
and,
means for controlling both all of said first predetermined distances which are parallel to and perpendicular to said first direction and all of said second predetermined distances which are parallel to and perpendicular to said first direction to result in a particular intentional misregistration between said dots of said second colored array and said dots of said first colored array, said misregistration having the property of enhancing said image.

1 more element

Apparatus for creating an enhanced color image on a movable planar surface using a plurality of arrays of dots, said surface moving in a first direction parallel to said surface, said apparatus comprising:

first apparatus that creates a first one of said arrays in a first color as a first colored array on said surface, said dots forming said first colored array being spaced at first predetermined distances from each other;
second apparatus that creates a second one of said arrays in a second color as a second colored array generally superimposed on said first colored array, said dots forming said second colored array being spaced at second predetermined distances from each other;
and,
control apparatus that controls both all of said first predetermined distances which are parallel to and perpendicular to said first direction and all of said second predetermined distances which are parallel to and perpendicular to said first direction to result in a particular intentional misregistration between said dots of said second colored array and said dots of said first colored array, said misregistration having the property of enhancing said image.

1 more element

In a computer-controlled system for creating an enhanced color image on a movable planar surface using a plurality of arrays of dots, said surface moving in a first direction parallel to said surface, a computer program product for use in said system, said computer program product including a computer usable medium having computer readable program code thereon, said computer readable program code comprising:

first program code for creating a first one of said arrays in a first color as a first colored array on said surface, said dots forming said first colored array being spaced at first predetermined distances from each other;
second program code for creating a second one of said arrays in a second color as a second colored array generally superimposed on said first colored array, said dots forming said second colored array being spaced at second predetermined distances from each other;
and,
program code for controlling both all of said first predetermined distances which are parallel to and perpendicular to said first direction and all of said second predetermined distances which are parallel to and perpendicular to said first direction to result in a particular intentional misregistration between said dots of said second colored array and said dots of said first colored array, said misregistration having the property of enhancing said image.

1 more element

A method for creating an enhanced color image on a movable planar surface using a plurality of arrays of dots, said surface moving in a first direction parallel to said surface, said method comprising:

creating a first one of said arrays in a first color as a first colored array on said surface, said dots forming said first colored array being spaced at first predetermined distances from each other;
creating a second one of said arrays in a second color as a second colored array generally superimposed on said first colored array, said dots forming said second colored array being spaced at second predetermined distances from each other;
and,
controlling both all of said first predetermined distances which are parallel to and perpendicular to said first direction and all of said second predetermined distances which are parallel to and perpendicular to said first direction to result in a particular intentional misregistration between said dots of said second colored array and said dots of said first colored array, said misregistration having the property of enhancing said image.

1 more element

Dependencies are inferred from the claim text.

Technique for printing a color image

Life of this patent

Technique for printing a color image

Life of this patent

Abstract

Claims92