Spot gloss and gloss control in an inkjet printing system
Embodiments of the invention provide a technique that effects spot gloss or gloss control and/or variations on one image without requiring clear inks. This is preferably accomplished by use of a multilayer printing process in which an image is first printed using a first set of color print heads and then cured, and in which the image is again printed using a second set of color print head, but where the image remains uncured for a predetermined interval to allow the ink drops applied to the media to spread and thus introduce a gloss effect.
1. A method for selectively applying gloss effects to any and/or all portions of an image, comprising:
with an inkjet printing system, printing, as a first layer and using pixel image data, an image on a medium using a first set of color print heads;
curing said printed image with a first curing operation;
subsequent to curing said printed image with the first curing operation, with said inkjet printing system, printing, using a second set of color print heads, as a second layer and using said pixel image data, a portion or all of the same image directly over a corresponding portion or all of said cured image printed by said first set of color print heads;
allowing said second layer to remain uncured for a predetermined interval until ink drops of said second layer spread to create a desired gloss effect; and
curing said second layer with a second curing operation once said desired gloss effect is achieved.
2. The method of claim 1 , further comprising:
generating at least two layers of said image using image editing software;
wherein at least one of said at least two layers comprises said first layer; and
wherein at least one of said at least two layers comprises said second layer.
3. The method of claim 1 , further comprising:
continuously moving a carriage in said inkjet printing system back and forth over a moving belt or table to deposit ink on said medium; and
in turn, continuously moving said medium by a belt, table, or roller;
wherein said belt, table, or roller moves said medium in a direction that is perpendicular to that of said carriage.
4. The method of claim 3 , further comprising:
providing multiple print heads on said carriage;
wherein said print heads are arranged in any of single row or multiple rows for each color.
5. The method of claim 1 , further comprising:
processing said image to be printed on said medium as a two-layer or multilayer image.
6. The method of claim 1 , wherein said ink comprises a UV curable ink.
7. The method of claim 1 , further comprising:
performing at least one of said first and second curing operations with one or more UV lamps.
8. The method of claim 7 , further comprising:
providing a covering or screening at a portion of said UV lamps, wherein no UV radiation or limited UV radiation output is available at said covered or screened portion.
9. The method of claim 8 , further comprising:
setting an amount of said covering or screening to determine an amount of gloss achieved.
10. The method of claim 8 , further comprising:
providing for said screening by a shutter mechanism that is variably adjustable to produce selected gloss effects.
11. The method of claim 10 , wherein said shutter mechanism comprises any of a mechanical shutter that is operated by a user or an actuator; or an electronic shutter comprising an electronic panel having a selectable degree of opacity.
12. The method of claim 11 , further comprising:
adjusting an amount of light allowed to pass through said mechanical shutter to effect ink curing as a function of any of density of said shutter or length of said shutter.
13. The method of claim 7 , further comprising:
introducing a variable gap between two or more curing lamps; and
initially passing said second layer through said gap;
wherein said second layer is remains substantially uncured while said second layer clears said gap.
14. The method of claim 13 , further comprising:
selectably varying said gap by moving said curing lamps relative to each other to establish said gap; and
setting said gap size to determine time required to cure said second layer.
15. The method of claim 1 , further comprising:
providing a printer dialog for selecting a degree of gloss applied by adjusting any of opacity, density, or length of a shutter or screen mechanism.
16. The method of claim 1 , further comprising:
performing at least said second curing operation with one or more UV LED lamps; and
selectably controlling at least a portion of said one or more LED lamps to vary said one or more LED lamps' energy output and set a cure time for said second layer.