The current art of printing technology is deficient in presenting an effective way to print a wide variety of colors on a plastic, synthetic, or other non-paper surface. Reproduction of a wider variety of colors can be achieved by improving inks to incorporate a white opaque ink layer which serves to achieve a high L* gamut in comparison with a plastic substrate that does not have a sufficiently white layer.
The present application extends the process spot color and process color simulation/emulation of spot color gamut. The present application produces color consistency in images containing process spot colors by using white toner as an additional separation and employing color control algorithms. White toner has the ability to make the colors light and to extend the upper part of the spot color gamut in the high L* range. One present embodiment uses white toner in the appropriate xerographic station/housing to apply white first onto the substrate, followed by MYCK. In another embodiment, the process spot color control system will use WMY, WCY, WCMY, WCM gamuts to extend the spot colors in the lighter region of the gamut.
In an alternative embodiment, the separation layers may also be prepared using color processing algorithms. In such an embodiment, a user would prompt a computer operable system by inputting a request for the preparation of the color separation layer and the software would break out the color separation layers in conformity with the user input specifications. A user request and user specifications may be input into the computer operable by use of a user interface such as, but not limited to, a keyboard, touch screen, mouse click, and the like.
The problem is to expand the range of process spot colors, process color simulation/emulation of spot color, printable on plastic, paper, synthetic or other media and achieve color consistency. In current document printing, the spot color gamut for high L* region is limited by the white measurement of the paper or other media. Color consistency is achieved in document printing using process controls and color controls technology. The current art of printing on packaging entails printing on flexible packaging, labels/tags, folding or corrugated cartons, plastics, ceramics, woods, and other such non-paper materials. To enable such printing, a white opaque ink layer is frequently used to achieve the proper color. Color consistency in packaging printing is currently achieved by an operator-controlled mechanical setups, ink control such as concentration, viscosity, mixing, ink key control, and the like.
This embodiment is particularly useful in printing on plastics because the white layer can change the achievable high L* region of the spot color gamut significantly compared with selected plastic substrates without the white layer. For document printing, this invention offers a smaller, incremental spot color gamut increase because the L* region of paper is approximately 95 and will change by only a few units with a white layer.
Two applications for this embodiment are xerographic printing systems for flexible packaging, where 85% of the substrates are plastic, and xerographic systems for printing labels. White toner may be fabricated by conventional means or by an emulsion aggregation process, where the Emulsion Aggregation (EA) is a process of growing 1-15 micron size particles from smaller, nanometer size constituents. The process is environmentally advantaged in that it is water based and does not use organic solvents commonly required to make particles in this size range. The process begins with the preparation of polymer particles in the nanometer size range emulsified in water. These particles and other desired components are then brought together in an aqueous based environment. Through control of the required chemical and physical conditions, the constituent particles are aggregated together to form larger particles. Once the particles reach their target size, the growth mechanism is halted and the particles are heated to achieve the desired shape. Particles can be completely spherical or somewhat irregular in shape. Since the mechanism of particle formation is one of controlled growth, rather than mechanical breakage, there is effective control of the particle size distribution and excellent geometric standard deviations are achieved.
The size or volume of the CMYK (i.e., spot color) gamut may be increased by adjusting the black level, also known as K. An increase in K results in a decrease in total spot color gamut volume, while a decrease in the value of K represents an increase in spot color gamut volume 200. The black levels, represented by the value K, changes in variation between a minimum value of K=0 to a maximum value of K=255. The top portion of the gamut 210 volume shown in
Within the L*a*b* response, the origin 230 represents the intersection of three axis, known as a*, b*, and L*. The a* axis 240 runs horizontally from left 250 to right 255 and represents the green to red values. Here the positive values running from the origin 230 to the right 255 cause a color to become more red in appearance as the value increases. The negative values running from the origin 230 to the left 250 cause a color to become more green in appearance as the negative number decreases moving further away from the origin. Another axis, the b* axis 260 runs back into the page and from left forward 270 to right rearward 275 and represents the blue and yellow values. Here the positive values running from the origin 230 back and right 275 cause a color to become more yellow in appearance as the value increases, while the negative values running from the origin to the front and left 250 cause a color to become more blue in appearance as the negative number decreases in value. The axis values typically run from zero at the origin to 150. Taken together, these two axes represent color saturation and hue. The axis running from top to bottom 280 of the page represents L* which is a measure of the lightness of the color, with the value at the origin 230 zero representing black. As the values increase from zero at the bottom or origin of the graph, the color becomes less black and more white with a numerical value of one hundred representing diffuse white 290 and a value exceeding one hundred representing specular white. This is the upper part of the gamut volume in the high L* range which is extended by the addition of white toner as a separation layer.
Using flood coating of white limits colors presented to a 100% area coverage white under layer. Using white toner in the xerographic station/housing allows for the incorporation of colors represented by additional gamuts in the lighter part of the chromatic colors, using any digitally addressable percent area coverage of white.
In one embodiment of the current application uses white toner in the appropriate xerographic station/housing such that white toner is applied first onto the substrate. For the purpose of the color controls algorithms, the imaging system will comprise of the use of four stations/housings; WMYC, when white toner is used for process spot colors. When black toner is used normal MYCK approach will be considered.
The differences and advantages between these embodiments and existing technology are:
Hence, all spot color controls using an automated spot color editor approach will be done with respect to absolute L*a*b* targets. Current algorithms use L*a*b* relative to paper.
The present application is not limited to colors using the CMK gamut or the CMKY gamut, and may also incorporate additional colors such as but not limited to the CMYKF gamut used in Hi-Fi color printing devices which may use extra colorants such as red, green, blue, orange, or purple colors.
It will be appreciated that various of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.
This application claims the benefit of U.S. Provisional Application No. 61/056,731, filed May 28, 2008, the disclosure of which is incorporated herein in its entirety by reference.
Number | Name | Date | Kind |
---|---|---|---|
4941038 | Walowit | Jul 1990 | A |
5299291 | Ruetz | Mar 1994 | A |
5534990 | Harris | Jul 1996 | A |
5574666 | Ruetz et al. | Nov 1996 | A |
5671340 | Chapman et al. | Sep 1997 | A |
5688626 | Patel et al. | Nov 1997 | A |
5745120 | De Baer et al. | Apr 1998 | A |
5837408 | Parker et al. | Nov 1998 | A |
6066422 | Blaszak et al. | May 2000 | A |
6575096 | Caruthers et al. | Jun 2003 | B1 |
6867883 | Cholewo et al. | Mar 2005 | B1 |
7032517 | Bestmann | Apr 2006 | B2 |
7054031 | Lee et al. | May 2006 | B2 |
7402370 | Kmiecik-Lawrynowicz et al. | Jul 2008 | B2 |
7499209 | Chopra et al. | Mar 2009 | B2 |
7507515 | Winters | Mar 2009 | B2 |
7734225 | Mashtare et al. | Jun 2010 | B2 |
7747210 | DiRubio et al. | Jun 2010 | B2 |
20030007164 | Lee et al. | Jan 2003 | A1 |
20030097947 | Caruthers et al. | May 2003 | A1 |
20040023135 | Rochford et al. | Feb 2004 | A1 |
20040187732 | Roman et al. | Sep 2004 | A1 |
20050215664 | Elwakil et al. | Sep 2005 | A1 |
20050282928 | Lin et al. | Dec 2005 | A1 |
20060082844 | White | Apr 2006 | A1 |
20060170938 | Ibarluzea et al. | Aug 2006 | A1 |
20070048020 | Silence | Mar 2007 | A1 |
20070188535 | Elwakil et al. | Aug 2007 | A1 |
20080043263 | Hancock et al. | Feb 2008 | A1 |
20090153887 | Lin et al. | Jun 2009 | A1 |
20090185201 | Lin et al. | Jul 2009 | A1 |
20090296113 | Mestha et al. | Dec 2009 | A1 |
20090296153 | Wang et al. | Dec 2009 | A1 |
20090316165 | Mestha et al. | Dec 2009 | A1 |
Number | Date | Country | |
---|---|---|---|
20090296173 A1 | Dec 2009 | US |
Number | Date | Country | |
---|---|---|---|
61056731 | May 2008 | US |