Patent Application
20230128872
The present disclosure generally relates to a recorded and fixed color image, including: a plurality of pixels; in which a pixel, of the plurality of pixels, contains two or more additive process color areas; in which each additive process color area, of the two or more additive process color areas, has a centroid located within an area of the pixel; in which locations of the centroids, within the area of the pixel, are present in two or more configurations in the plurality of pixels. A method for making the color image is also disclosed.
Generally, color images have been recorded with colorants using subtractive color blending, such as cyan, magenta, yellow, and black (CMYK). The subtractive colorants, widely referred to as process colors, are printed in specific pixels with defined colored areas. Ideally, the pixels are printed in perfect register; however, it is more likely than not, that registration errors exist causing an overlap in the subtractive colors. Subtractive colors are generally transparent so that an overlap would still allow transmission of the underlying subtractive color. For this reason, color images produced from subtractive colors are more resilient to registration errors. However, these color images have a limited optical performance because the lightness of the color image is limited by the lightness of the white background, the substrate on which the color image is printed.
Additive colors are opaque by definition and can exhibit a more specular reflection, which could result in improved optical performance. However, if an additive color area is mis-registered relative to where it should be and as a result overlaps with an adjacent additive color area, only the color on top in the overlap would contribute to the color blend, resulting in a color bias within the color image. A registration error is likely to be present in the whole color image or a large area of the color image and the color on top would consistently go over the same adjacent additive color area that is reduced in area as a result. With the likelihood of registration errors during the printing process, additive colors are generally not used to create color images.
Additionally, the registration requirement for using additive colors would make it difficult to create half-tones with a random patterned color area placement size. In particular, color areas generally need to be placed and sized knowing where adjacent color areas are, or will be, to avoid an unintended overlap.
What is needed is a color image with additive colors in which the additive colors are positioned within the pixels to avoid a color bias, in the event of a mis-registration. The size of the additive color areas within a pixel, and/or within a plurality of pixels, can allow for half-tones. Additionally, the additive color areas can be positioned in a random sequence or an encoded sequence to reduce the likelihood of producing a counterfeited color image. Further, the color image can have specular, metallic, light reflection, which cannot be achieved with the use of transparent subtractive colors.
Features of the present disclosure are illustrated by way of example and not limited in the following figure(s), in which like numerals indicate like elements, in which:
In an aspect, there is disclosed a recorded and fixed color image, including: a plurality of pixels; in which a pixel, of the plurality of pixels, contains two or more additive process color areas; in which each additive process color area, of the two or more additive process color areas, has a centroid located within an area of the pixel; and in which locations of the centroids, within the area of the pixel, are present in two or more configurations in the plurality of pixels.
In another aspect, there is disclosed a method of forming a color image, comprising: providing a plurality of pixels; wherein a pixel, of the plurality of pixels, contains two or more additive process color areas; wherein each additive process color area, of the two or more additive process color areas, has a centroid located within an area of the pixel; wherein locations of the centroids, within the area of the pixel, are present in two or more configurations; and overlapping two or more pixels, of the plurality of pixels, wherein the overlap does not result in an average color bias or change of the white balance in the colored image.
Additional features and advantages of various embodiments will be set forth, in part, in the description that follows, and will, in part, be apparent from the description, or can be learned by the practice of various embodiments. The objectives and other advantages of various embodiments will be realized and attained by means of the elements and combinations particularly pointed out in the description herein.
For simplicity and illustrative purposes, the present disclosure is described by referring mainly to an example thereof. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. It will be readily apparent however, that the present disclosure may be practiced without limitation to these specific details. In other instances, some methods and structures have not been described in detail so as not to unnecessarily obscure the present disclosure.
Additionally, the elements depicted in the accompanying figures may include additional components and some of the components described in those figures may be removed and/or modified without departing from scopes of the present disclosure. Further, the elements depicted in the figures may not be drawn to scale and thus, the elements may have sizes and/or configurations that differ from those shown in the figures.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only, and are intended to provide an explanation of various embodiments of the present teachings. In its broad and varied embodiments, disclosed herein are a color image, and a method of making a color image.
As shown in
The color image can be recorded and fixed on a substrate, such as paper, plastic, glass, etc. By “recorded” it is understood to mean that the color image is set down, for example, printed so the color image can be seen in the future. The color image can be recorded by an electrostatic printing method, but other methods can be used. By “fixed” it is understood to mean that the color image is intended to be permanent for the functional life of the colorants or recording.
The color image can comprise a plurality of pixels 10. The plurality of pixels can be from two or more pixels to an unlimited number of pixels. The number of pixels in the plurality of pixels can vary depending upon the quality/clarity of the color image, wherein a higher quality/clarity color image includes a greater number of pixels as compared to a lower quality/clarity color image. For the sake of simplicity, the color image of
A color image recorded with additive colorants can be, in general, a combination of three or more additive process colors printed in half-tone, variable size color areas, with the size of the color areas determining the color blend. In general, the number of half-tone dots, or the areas reserved for these half-tone dots can be the same for each process color. An area that comprises one of each and adjacent reserved areas for the additive process colors can be referred to as a pixel. The number of areas reserved for each color can be generally identical and the number of pixels, and the process color areas can be each configured in a fixed pitch matrix with a slight offset between the matrices to make the color areas not overlap. Potential implementations use matrices with variable spacing or no matrix for one or more of the colors and a variable placement of the color areas. The invention does not rely on the use of fixed pitch matrices and pixels. Half-tones can also be achieved with fixed size additive process color areas whereby the color can be determined by the distance between additive process color areas. The invention is illustrated based on the use of pixels. This illustration is not intended as a limitation to the use of matrices or pixels.
A pixel, of the plurality of pixels, can contain two or more additive process color areas 14. An additive process color area 14 is understood to mean an area, within a pixel 10, that can be designated for an additive process color. An additive process color is a color, such as red, green, or blue, that can be combined with at least one other additive process color to produce a plurality of colors including white. In an aspect, a pixel 10 can include one additive process color area 14. For example, the pixel 10 can be red. As shown in
Each additive process color area 14 can be the same or different within a pixel, and within the plurality of pixels, with regard to shape, size, color, and location. As will be discussed in more detail later, a color image that includes a plurality of pixels, in which a portion of the pixels include variations with regard to the additive process color areas 14, can be less likely to exhibit a color bias, and/or can be less likely to be counterfeited. In this manner, the color image can be used in a security document.
As shown in
In an aspect, each additive process color area 14, of the two or more additive process color areas, can have a same size. As shown in
In another aspect, at least one additive process color area 14, of the two or more additive process color areas, can have a different size. As shown in
Each additive process color area 14 can have a centroid, which is understood as a center of mass, located with an area of the pixel. The area of the pixel is understood to be a total area including all of the additive process color areas 14, including any reserved areas. A pixel 10 can have two or more additive process color areas 14, and each additive process color area 14 can have a centroid, and wherein locations of the centroids can be present in two or more configurations in the plurality of pixels. As with the variations in the additive process color areas 14 discussed above, varying the locations of the centroids within the area of the pixel can decrease a color bias and/or reproducibility of the color image. In an aspect, the locations of the centroids within the area of the pixel, and/or within the plurality of pixels can be a random or quasi-random sequence. In another aspect, the locations of the centroids within the area of the pixel can encode a predetermined sequence, e.g., the numerical digits for π. Centroids and their locations will be explained more fully with regard to
Each additive process color area 14 can include a reflective pigment. The reflective pigment can be a metallic pigment, with a metallic reflective layer. The terms “metallic” or “metallic layer” used herein, unless otherwise stated, are intended to include all metals, metal blends and alloys, pure metal or metal alloy containing materials, compound, compositions, and/or layers. The pigment can be opaque. The pigment is not a mica flake coated with titanium dioxide and comprises an opaque pigment, with less than 50% transmission over the visible spectrum. The metallic reflective layer can include metals and/or metal alloys. In one example, any materials that have reflective characteristics can be used. Nonlimiting examples of a material with reflecting characteristics include aluminum, silver, copper, gold, platinum, tin, titanium, palladium, nickel, cobalt, rhodium, niobium, chromium, and compounds, combinations or alloys thereof. Examples of suitable reflective alloys and compounds include bronze, brass, titanium nitride, and the like, as well as alloys of the metals listed above such as silver-palladium. The metallic reflective layer can have an inherent color such as copper, gold, silver copper alloys, brass, bronze, titanium nitride, and compounds, combinations or alloys thereof. The pigment can be encapsulated with a non-conductive layer, such as an organic polymer or metal oxide.
The reflective pigment can be a color shifting pigment. A color shifting pigment can exhibit a first color at a first viewing angle and a second color at a second viewing angle that is different from the first viewing angle. A color shifting pigment can include the following multilayered optical structure: absorber layer/dielectric layer/reflective layer/dielectric layer/absorber layer.
The reflective pigment can be a broad-spectrum reflective pigment. In one example, the materials for the metallic reflective layer can include any materials that have reflective characteristics in the desired spectral range. For example, any material with a reflectance ranging from 50% to 100% in the desired spectral range. An example of a reflective material can be aluminum, which has good reflectance characteristics, is inexpensive, and easy to form into or deposit as a thin layer. Other materials can also be used in place of aluminum. For example, copper, silver, gold, platinum, palladium, nickel, cobalt, niobium, chromium, tin, and combinations, blends or alloys of these or other metals can be used as reflective materials. In an aspect, the material for the reflector layer can be a white or light colored metal. In other examples, the reflector layer can include, but is not limited to, the transition and lanthanide metals and combinations thereof; as well as metal carbides, metal oxides, metal nitrides, metal sulfides, a combination thereof, or mixtures of metals and one or more of these materials.
An amount of the reflective pigment in each additive process color area can be the same. For example, as shown in
Each additive process color area, within a first pixel, can be present in a first sequence. Each additive process color area, within a second pixel, can be present in a second sequence. As shown in
An additive process color area 14, within a pixel, and/or with a portion of a plurality of pixels, can provide a same level of color performance as another additive process color area 14. If there is a same level of color performance, then a size of an additive process color area 14 is likely the same. In an aspect, an additive process color area 14 can have a bigger sizer for a weaker performing color. Similarly, an additive process color area can have a smaller size for a stronger performing color. The inclusion of various sized and/or shaped additive process color areas 14 in a pixel, and/or with a portion of the plurality of pixels, can result in a white balance in the color image.
However, in a high volume printing process, for example, during printing of banknotes, perfect registration of pixels is not likely. Instead, it is more likely, that there would be a printing error, such as mis-registration.
As discussed above,
The locations of the centroids within the area of a pixel form a random or quasi-random sequence. The combination of different configurations of centroids (e.g., vertical/horizontal) and different sequence of additive process color areas decreased a color bias in the color image.
There is also disclosed a method of forming a color image, including providing a plurality of pixels; wherein a pixel, of the plurality of pixels, contains two or more additive process color areas; wherein each additive process color area, of the two or more additive process color areas, has a centroid located within an area of the pixel; wherein locations of the centroids, within the area of the pixel, are present in two or more configurations; and overlapping two or more pixels, of the plurality of pixels, wherein the overlap does not result in a local color bias in the colored image. In this manner, the color image would not include induced fishbone-like patterns or line artifacts. Any repetitive pattern in the variation of centroid location can result in induced line artifacts or fishbone-like patterns as the similar pixels form a color pattern in the matrix. The color location within the pixels can be enough to cause this. This forming of these visible patterns, showing as lines of fishbone like structures, is eliminated, reduced to image noise, by using a random or quasi random sequence without significant repetitive patterns.
The step of providing can including aligning the plurality of pixels in a configuration so as to form a color image. For example, the step of providing can include recording the plurality of pixels in an aligned configuration to form a color image. A first additive process color area of a pixel can be printed, subsequently followed by a second additive process color area of the same pixel. The additive process color areas can be sequentially printed until an entire pixel has been provided.
In an aspect, the step of providing can include increasing a size of an additive process color area, within a pixel, for a reflective pigment that exhibits poor color performance. The step of providing can include decreasing a size of an additive process color area, within a pixel, for a reflective pigment that exhibits poor color performance.
In an aspect, the step of providing can include changing a shape of an additive process color area, within a pixel, relative to the other, of the two or more additive process color area.
In an aspect, the step of providing can include changing the location of the centroid in an additive process color area in a first pixel relative to the location of the centroid in a same additive process color area in an adjacent second pixel.
In an aspect, the step of providing an include changing a sequence of the two or more additive process color areas in a first pixel relative to a different sequence of two or more additive process color areas in a second adjacent pixel.
The step of overlapping can include overlapping a portion of a perimeter of a first pixel with a portion of a perimeter of an adjacent second pixel. For example, a first additive process color of a first pixel can overlap with a portion of a second additive process color of a second adjacent pixel, within the plurality of pixels. In another aspect, a first additive process color can overlap with a second additive process color within a pixel. The overlap can reduce a white balance change of the colored image when the overlap is smaller than a dimension of the pixel. The step of overlapping can be in one direction of the color image, e.g., an overlap upward. The step of overlapping can be in two directions of the color image, e.g., an overlap upward and to the right. The step of overlapping can be random throughout the color image.
In the method, the plurality of pixels is not configured in a repetitive pattern, matrix or raster. Instead, the plurality of pixels can be aligned in a random sequence.
From the foregoing description, those skilled in the art can appreciate that the present teachings can be implemented in a variety of forms. Therefore, while these teachings have been described in connection with particular embodiments and examples thereof, the true scope of the present teachings should not be so limited. Various changes and modifications can be made without departing from the scope of the teachings herein.
This scope disclosure is to be broadly construed. It is intended that this disclosure disclose equivalents, means, systems and methods to achieve the devices, activities and mechanical actions disclosed herein. For each device, article, method, mean, mechanical element or mechanism disclosed, it is intended that this disclosure also encompass in its disclosure and teaches equivalents, means, systems and methods for practicing the many aspects, mechanisms and devices disclosed herein. Additionally, this disclosure regards an article and its many aspects, features and elements. Such an article can be dynamic in its use and operation, this disclosure is intended to encompass the equivalents, means, systems and methods of the use of the device and/or optical device of manufacture and its many aspects consistent with the description and spirit of the operations and functions disclosed herein. The claims of this application are likewise to be broadly construed. The description of the inventions herein in their many embodiments is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.
