JP2011140120A - Image display medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image display medium which can display a multi-color image giving a natural impression, while maintaining anti-copying function, by taking the advantages of a diffraction grating which gives rise to a color change in compliance with a viewing angle. <P>SOLUTION: This image display medium reveals a multi-color image by dividing a transparent sheet into a plurality of areas, then arranging a monochromatic image or an image of a plurality of colors obtained by superposing monochromatic images in each of the areas, and laminating a plurality of the monochromatic images over each other. In this case, some of the monochromatic images selected from among the monochromatic images or the monochromatic images making up the images in a plurality of colors, are constituted using the diffraction grating. On the other hand, the other images are colored in a coloring agent. Color change occurrs only in the monochromatic image constituted using the diffraction grating, even if the viewing angle is changed, and no color change takes place in the other monochromatic image. Thus it is possible to display a multi-color image giving a natural impression, even if the viewing angle is not strictly specified. Since the duplicated image of this multi-color image reveals no color change, even if the viewing angle is changed significantly, it is possible to easily distinguish between the genuine image and the duplicated image. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an image display body that displays a multicolor image by superimposing a plurality of single color images showing different colors.

  Image display bodies that display a multicolor image by superimposing a plurality of single color images showing different colors are well known.

  For example, a general multicolor printed material is configured by overprinting four color single-color images. That is, four colors are obtained by adding black (K) to three colors of yellow (Y), magenta (M), and cyan (C), which indicate the three primary colors. In such a general printed matter, first, yellow (Y) ink is printed to form a yellow (Y) single color image, and then magenta (M) ink is printed on the yellow (Y) single color image. Thus, a magenta (M) monochrome image is formed. Similarly, a cyan (C) monochrome image and a black (K) monochrome image are sequentially overprinted. In any case, the printing order may differ, but in any case, the multicolor image obtained by superimposing the four-color single-color images has substantially the same color as the color document and gives a natural impression. It is a multicolor image and is a multicolor image having the same color from any angle.

  On the other hand, a display body using a diffraction grating is known as an image display body whose color changes depending on the viewing angle. The diffraction grating in practical use is a relief-type reflection diffraction grating, and the surface of the substrate such as a transparent resin is provided with fine irregularities constituting the diffraction grating, and a light reflection layer is provided on the irregular surface. It is a thing. In this relief-type reflective diffraction grating, the reflected light from the light reflecting layers interfere with each other to form diffracted light. Since the wavelength of the diffracted light varies depending on the incident angle of the incident light, the wavelength of the diffracted light, that is, the color differs depending on the observation angle. For example, a long wavelength red diffracted light can be observed at a certain observation angle, but a short wavelength purple diffracted light can be observed at another observation angle. In any case, the diffracted light that can be observed is a color that constitutes the spectrum of light.

  And since the display body using a diffraction grating changes color according to an observation angle as mentioned above, it is utilized, for example as a copy prevention technique. Even if this display is copied, the obtained copy image is composed of a colorant, so that the color does not change even if the observation angle is changed. For this reason, the genuine product and the copy can be discriminated by inspecting the presence or absence of a color change depending on the observation angle.

  An attempt to construct a multicolor image that gives a natural impression using this diffraction grating is described in Patent Document 1. That is, the image display body described in Patent Document 1 decomposes an image into pixels and configures the pixels with a diffraction grating, and gives a natural impression when the image is viewed from a specific observation angle. The pitch of the diffraction grating constituting each pixel is controlled.

  However, when such a multicolor image is observed, it is not realistic to make the observation angle exactly match the specific angle. Therefore, when observed from an observation angle slightly deviated from the specific angle, the color of the image display body described in Patent Document 1 changes greatly, and all colors constituting the image change. Observing an image is virtually difficult. It is also difficult to display a multicolor image having substantially the same color as that of, for example, a color original and giving an image similar to that of the image formed of the diffraction grating.

JP-A 63-305380

  Therefore, the present invention provides an image forming body that displays a multicolor image that gives a natural impression while maintaining the copy prevention function by taking advantage of the diffraction grating that the color changes according to the viewing angle. It is intended to do.

The invention according to claim 1 is an image display body that displays a multicolor image by superimposing a plurality of single color images showing different colors.
Among the plurality of monochromatic images, a part of the monochromatic image is composed of a diffraction grating, and the color is indicated by diffracted light generated from the diffraction grating,
The monochromatic image showing other colors is a monochromatic image colored with a colorant,
This is an image display body characterized by the above.

  According to the present invention, some of the monochromatic images constituting the multicolor image are composed of the diffraction grating, and the other monochromatic images are colored with the colorant. The color changes only in some monochromatic images (monochromatic images composed of diffraction gratings), and there is no color change in other monochromatic images (monochromatic images colored with a colorant). Further, if the change in the observation angle is small, the color change is also small, the change in the impression of the multicolor image is slight, and the impression of the multicolor image is virtually unchanged. Therefore, it is possible to display a multicolor image that gives a very natural impression without strictly specifying the observation angle.

  However, the change in color of a monochromatic image composed of diffraction gratings is large if the change in observation angle is large. When this multicolor image is copied, the color of the obtained copy image does not change even if the observation angle is changed greatly. Therefore, by determining whether the color changes according to the change of the observation angle, Thus, it is possible to easily distinguish between a genuine multicolor image and a copy image.

  Next, the invention according to claim 2 is the image display body according to claim 1, wherein each of the plurality of monochrome images is a monochrome image obtained by color-separating the multicolor image. is there.

  In the second aspect of the present invention, each of the plurality of single-color images is a single-color image obtained by color-separating the multi-color image (that is, a color document). The multicolor image obtained in this way is the same as the color original before color separation. Therefore, this multicolor image is recognized as a single image as a whole, and is, for example, a multicolor image of a castle or the like as in a specific example described later. In this respect, a photographic image is formed as a single color image of a specific color, and is distinguished from a multiple image such as an image in which a character image of another color is superimposed on this photographic image.

  By the way, as described above, the diffracted light generated by the monochromatic image composed of the diffraction grating is a color constituting the spectrum of light, and typically, red (R), green (G (G) constituting the three primary colors of light. ), Blue (B).

  On the other hand, the monochromatic image colored by the colorant is colored by absorbing the specific wavelength component of visible light and reflecting or transmitting the remaining wavelength component, so that two or more colors different from each other. When the single color images are superimposed at the same position, the two colors are mixed, and the obtained color becomes the color specified by the principle of the subtractive color mixing. For this reason, the colorant used in this monochromatic image is generally based on the three colors of yellow (Y), magenta (M), and cyan (C) indicating the three primary colors. For example, yellow (Y ) And magenta (M) are mixed in red (R). Further, when yellow (Y) and cyan (C) are mixed, green (G) color is shown, and when magenta (M) and cyan (C) are mixed, blue (B) color is shown.

  Therefore, as a single color image colored by the colorant, a full color multicolor image is displayed using three types of single color images having yellow (Y), magenta (M), and cyan (C) colors, respectively. As a monochromatic image composed of a diffraction grating, a monochromatic image showing a color selected from red (R), green (G), and blue (B) is used, and a monochromatic image composed of this diffraction grating is used. It is composed of four types of monochromatic images (three types of monochromatic images each having yellow (Y), magenta (M), and cyan (C) colors) and a diffraction grating superimposed on the full-color multicolor image. It is desirable to obtain a multicolor image on which a single color image is superimposed. Of course, it is also possible to use two or more types of monochromatic images composed of diffraction gratings to form a multicolor image in which a total of five types or six types of monochromatic images are superimposed.

  In addition, when all three colors of yellow (Y), magenta (M), and cyan (C) are mixed, a black color is exhibited. However, since the black color lacks clarity, generally, in addition to these three colors, carbon In many cases, a black monochromatic image using black as a colorant is overprinted. Also in this invention, what shows black as a monochromatic image colored with the coloring agent can be used, without being limited to the said three colors.

  The inventions described in claims 3 to 5 specify the color of a single-color image composed of a diffraction grating and the color of a single-color image colored with a colorant, respectively.

  That is, the invention described in claim 3 is characterized in that the monochromatic image formed of the diffraction grating shows a color selected from colors constituting the spectrum of light. The invention according to claim 4 is characterized in that the single-color image colored with the colorant exhibits a color selected from the three primary colors. 4. The image display body according to any one of 3 above. The invention according to claim 5 is the image display body according to any one of claims 1 to 3, wherein the single-color image colored with the colorant is black.

  Next, a plurality of single-color images according to the present invention can be formed into a multicolor image by superimposing all of them on a single base sheet, but some of the plurality of single-color images It is also possible to form a multicolor image by forming on a transparent film, forming another single color image on one base sheet, and aligning and superimposing these transparent film and base sheet. Further, a single transparent sheet is divided into a plurality of areas via a fold line, a part of each of the plurality of monochrome images is formed in each of the plurality of areas, and the plurality of single colors are folded from the fold line. A multicolor image can also be constructed by aligning and overlaying the images.

The invention according to claim 6 includes a base sheet and a transparent sheet, and a single color image or a multi-color image in which a single color image is superimposed is formed on each of the base sheet and the transparent sheet. In the image display body that displays the multicolor image by superimposing the images by overlapping the sheets,
Among the monochromatic images constituting the monochromatic image or the multicolor image, a part of the monochromatic image is composed of a diffraction grating, and the color is shown by diffracted light generated from the diffraction grating,
The other image is a monochromatic image colored with a colorant.
This is an image display body characterized by the above.

In the invention according to claim 7, the transparent sheet is divided into a plurality of areas via folding lines, and a single color image or a multi-color image in which a single color image is superimposed is formed in each of the plurality of areas. In an image display body that displays a multicolor image by folding the plurality of single color images with each other by bending from the folding line,
Among the monochromatic images constituting the monochromatic image or the multicolor image, a part of the monochromatic image is composed of a diffraction grating, and the color is shown by diffracted light generated from the diffraction grating,
The other image is a monochromatic image colored with a colorant.
This is an image display body characterized by the above.

  As is clear from the above description, according to the present invention, it is possible to display a multicolor image that gives a very natural impression without strictly specifying the observation angle and even if the observation angle slightly changes. Is possible. Moreover, when this multicolor image is copied, it is possible to easily discriminate between a genuine multicolor image and a copy image.

Specific examples of color images of color originals Specific examples of monochromatic images obtained by color separation of color images Plan view showing a specific example of an image display body Explanatory diagram showing how to use the image display Plan view of an image display body in a state of forming a multicolor image

  The image display according to the present invention displays a multicolor image by superimposing a plurality of single color images.

  The plurality of single-color images may be provided by superimposing one sheet material as a base sheet on one side of the base sheet. In this case, the image display body according to the present invention includes the base sheet and a plurality of single-color images provided on one side of the base sheet.

  Further, the image display body according to the present invention may be obtained by providing each of a plurality of single color images on each of a plurality of sheet materials and thus stacking the plurality of sheet materials provided with the single color images. In this case, the sheet material stacked on the base sheet is required to be transparent except for the base sheet disposed on the lowermost side among the plurality of sheet materials. In this case, the image display according to the present invention is composed of a plurality of sheet materials provided with a single color image. Of course, each of the plurality of sheet materials can be provided not only with a single color image but also with a plurality of color images in which a plurality of single color images are superimposed.

  Alternatively, a transparent sheet may be used as a base sheet, and the base sheet may be divided into a plurality of areas via folding lines, and each of the plurality of monochrome images may be provided in each of the plurality of areas. In this case, a multicolor image can be formed by folding from the folding line and superimposing a plurality of the single color images on each other. In this case, it is necessary that the monochromatic images provided in the areas adjacent to each other via the folding line have a mirror image relationship in which the left and right are reversed. Of course, not only a single color image can be provided in each area, but also a plurality of color images obtained by superimposing a plurality of single color images can be provided.

Of the plurality of monochrome images, some of the monochrome images need to be composed of diffraction gratings. Further, this monochromatic image needs to show its color with diffracted light generated from the diffraction grating. As such a diffraction grating, for example, a relief type reflection type diffraction grating can be used. A relief type reflective diffraction grating is well known, and can be manufactured by providing fine irregularities constituting the diffraction grating on the surface of a substrate such as a transparent resin, and providing a light reflecting layer on the irregular surface. . Then, the monochromatic image can be formed by removing a part of the light reflecting layer and patterning the monochromatic image. In addition, a monochrome image can be expressed by a set of dot-like pixels. In this case, it is desirable to configure this pixel by patterning the light reflecting layer into a pixel shape. The size of the pixel may be 100 μm, for example.

  A metal thin film or a high refractive index transparent thin film can be used as the light reflecting layer, and the light reflecting layer can be formed along the irregularities of the surface by a vacuum film forming method. Aluminum or copper can be used as the metal thin film. Titanium oxide or the like can be used as the high refractive index transparent thin film. Moreover, as a vacuum film-forming method, a vacuum evaporation method or a sputtering method can be used. The light reflecting layer can be patterned by, for example, providing an etching resist on the light reflecting layer and then etching. In addition, a solvent-soluble resin film is provided in a pattern on the uneven surface, the light-reflecting layer is formed by coating the resin film, and then a solvent is applied to form a solvent-soluble resin film on the resin film. It is also possible to pattern the light reflecting layer by dissolving and removing together with the superimposed light reflecting layer.

  As described above, since the diffracted light generated from the diffraction grating generally has a color that constitutes the spectrum of light, it is desirable that the monochromatic image composed of this diffraction grating also has the color that constitutes the spectrum of light. In addition, for the convenience of color separation of a color original to form this single color image, it is desirable that this single color image shows a color selected from the three primary colors of light. That is, the color selected from red (R), green (G), and blue (B). These single-color images showing red (R), green (G) or blue (B) can be easily formed by color-separating a color original, and are colored with a colorant as will be described later. Matching with a monochrome image is also easy. When the color of red (R) is shown, the number of irregularities constituting the diffraction grating is about 1150 / mm (pitch is about 0.43 μm), where the number of convex portions is the number of lines. In the case of green (G), the number of lines is about 1310 / mm (pitch of about 0.38 μm), and in the case of blue (B), the number of lines is about 1550 / mm (pitch of about 0.32 μm).

  In addition, since the color of a monochromatic image composed of a diffraction grating also changes when the observation angle is changed, in the present invention, when referring to “color of a monochromatic image composed of a diffraction grating”, the color is an image display body. Is a color when observed from a predetermined appropriate angle. The appropriate angle is usually the front of the image display body.

  Next, in the present invention, except for the monochromatic image composed of the diffraction grating, the monochromatic image showing other colors needs to be a monochromatic image colored with a colorant. Although a dye or a pigment can be used as the colorant, it is desirable that the monochromatic image be transparent even when a pigment is used.

  As described above, the color by the colorant is colored by absorbing a specific wavelength component from the visible light spectrum and reflecting or transmitting the remaining wavelength component, so that the monochromatic image colored by the colorant is used. It is desirable to indicate a color selected from among the three primary colors. That is, the color is selected from among yellow (Y), magenta (M), and cyan (C). Desirably, three types of single color images of a single color image of yellow (Y), a single color image of magenta (M), and a single color image of cyan (C) are used as the single color image colored by the colorant. use. In this case, a full-color multicolor image including the intermediate colors can be displayed by superimposing these three types of single-color images. In addition, these three types of single-color images can be easily formed by separating the color original.

  In addition to these three types of single-color images, a black-colored single-color image can also be used as a single-color image colored with a colorant. In this case, the monochrome image of black (K) color does not need to be transparent, but rather is preferably opaque. This black (K) color monochromatic image can also be easily obtained from a color original.

  Next, a method for forming a monochrome image composed of a diffraction grating and a monochrome image colored with a colorant will be described. As described above, any of these single color images can be formed by color separation of a color original.

  An example will be described in which a monochromatic image composed of diffraction gratings shows a green (G) color. The other monochromatic images are monochromatic images colored with a colorant. The monochromatic image has a yellow (Y) color, the magenta (M) color, and the cyan (C) color. Suppose that there are four types of monochromatic images of black (K) color.

  That is, a transparent sheet (color filter) having a green (G) complementary color (magenta) color is superimposed on a color original, and a transmission image is photographed. In this case, in the color image of the color document, the region exhibiting the green (G) color is a region that absorbs the wavelength component indicating the color other than the green (G) and transmits the green (G) color light. . On the other hand, since the color filter absorbs green (G) color light, the transmitted light disappears in a region where both are superimposed, and a black image is taken. In this way, the green (G) component can be extracted from the color image of the color original, and the monochrome image can be obtained. Note that the green (G) component can be electronically extracted by a computer after a color original is photographed.

  Next, a method of extracting a single color image of yellow (Y) from a color image of a color original will be described. That is, a color image of a complementary color (blue) of yellow (Y) is superimposed on a color original to photograph a transmission image. The transmission image obtained in this manner is obtained by extracting a region having a yellow (Y) component from the color image, and this transmission image includes a region having a green (G) component. Therefore, by taking the difference between the transmission image showing the yellow (Y) component and the transmission image showing the green (G) component, it is possible to extract a monochrome image of the yellow (Y) color. For example, a transmission image showing a green (G) component may be superimposed on a negative film of a transmission image showing a yellow (Y) component, and the transmission image taken. Of course, these series of steps can also be performed by a computer after photographing a color original.

  Next, a method for extracting a single color image of cyan (C) from a color image of a color original will be described. That is, a color original is overlaid with a color filter of cyan (C) complementary color (red), a transmission image is taken, and then a difference between the transmission image and a transmission image showing a green (G) component is obtained. A monochrome image of cyan (C) color can be extracted.

  It should be noted that a monochromatic image composed of a diffraction grating having a metal thin film as a light reflecting layer on both a monochromatic image of yellow (Y) color and a monochromatic image of cyan (C) (however, the color of green is When a multicolor image is displayed by superimposing those shown, it is not necessary to take the difference between the transmission image showing the yellow (Y) component and the transmission image showing the green (G) component. Further, it is not necessary to take the difference between the transmission image showing the cyan (C) component and the transmission image showing the green (G) component. This is because the metal thin film is opaque.

  Next, in order to extract a single color image of magenta (M) color from a color image of a color original, a transparent image may be taken by overlaying the color original with a magenta (M) complementary color (green) color filter. .

  Further, in order to extract a monochrome image of black (K) color, it is only necessary to shoot with a monochrome film without using a color filter.

  The case where the monochromatic image composed of the diffraction grating shows the color of green (G) has been described above as an example, but the monochromatic image composed of the diffraction grating has the color of red (R) or blue (B). Similarly, it is possible to obtain each monochrome image.

  The invention will now be described by way of example with reference to the drawings.

  FIG. 1 of the drawings shows a color image of a color original. This color image is a photographic image of a castle surrounded by trees. As can be seen from the figure, a portion having a green color (for example, a portion of a tree) occupies a large area.

  FIGS. 2A to 2E show single color images obtained by color-separating this color image. FIG. 2A shows the extracted black (K) component of the color image. FIG. 2B shows a magenta (R) component extracted, and FIG. 2C shows a green component (G) extracted. FIG. 2D shows the extracted cyan component (C) of the color image, and FIG. 2E shows the extracted yellow component (Y) of the color image.

  Next, a transfer foil having a monochromatic image composed of a diffraction grating was manufactured using the monochromatic image of green (G). That is, first, a transparent resin was applied onto a resin film through a release layer to form a film, and the surface of the transparent resin layer was embossed to form fine irregularities. The unevenness constitutes a diffraction grating that generates green (G) diffracted light with respect to the front direction. The unevenness was uniformly formed on the entire surface of the transparent resin layer. Next, aluminum was vacuum-deposited on the uneven surface to form a thin film, which was used as a light reflecting layer. And after apply | coating a photoresist on this light reflection layer and forming a film, a photoresist is exposed and developed through the photomask which has the said monochrome image of green (G), and green (G) The photoresist having the same pattern as that of the single-color image was selectively left to expose the light reflecting layer in other portions. Then, using the remaining photoresist as an etching resist, the light reflection layer at the exposed portion was selectively etched and removed, and the surface of the transparent resin layer at this portion was exposed. Next, the remaining photoresist was stripped to expose the light reflecting layer remaining in the same pattern as the single color image of green (G). Finally, an adhesive was applied to the entire surface including the light reflection layer to produce a transfer foil having a monochromatic image composed of a diffraction grating. In addition, the unevenness | corrugation of the exposed transparent resin layer surface was filled by application | coating of this adhesive agent, and the diffraction grating of this site | part disappeared.

  Next, the transparent sheet is used as a base sheet, and the base sheet is divided into a first area and a second area via a fold line, and a yellow (Y) single color is included in the first area. The image was printed with a cyan (C) single color image superimposed. As the printing ink, an ink containing a yellow pigment and an ink containing a blue pigment were used, respectively. Note that any single color image is transparent.

Then, the transfer foil was aligned with this yellow printed image and adhered by an adhesive layer, and then the resin film was peeled and removed to transfer the light reflecting layer and the transparent resin. At this time, the part located under the light reflecting layer is hidden behind the light reflecting layer and cannot be observed.

  Next, a black (K) single color image and a magenta (M) single color image were printed in this order in the second area of the base sheet. As the printing ink, an ink containing a black pigment (carbon black) and an ink containing a red pigment were used. The magenta (M) monochrome image is transparent, but the black (K) monochrome image is opaque.

  The image display body thus obtained is shown in FIG. This image display body is composed of a transparent sheet whose surface is divided into a first area and a second area. In the first area, a yellow (Y) monochrome image, cyan (C) Three types of single-color images composed of a single-color image and a green (G) single-color image are formed so as to overlap in this order. Among these, the yellow (Y) monochrome image and the cyan (C) monochrome image are provided by printing, and are monochrome images colored with a colorant (pigment). On the other hand, the green (G) monochromatic image is composed of a diffraction grating, and is a monochromatic image whose color is indicated by diffracted light generated from the diffraction grating. The green (G) monochromatic image is observed in vivid green when observed from the appropriate angle (front), and even when the observation angle slightly deviates from the appropriate angle (front), the color is substantially Although not changed, for example, when the observation angle is observed from an angle shifted by 75 degrees from the appropriate angle (front), the color changes greatly.

  In the second area of the image display body, a black (K) single color image and a magenta (M) single color image are superimposed in this order. Then, the image provided in the first area and the image provided in the second area are arranged in a bilaterally symmetrical relationship with the folding line as the target center. Of course, both images have a mirror image relationship.

  The image display body is bent from a folding line, and the image provided in the first area and the image provided in the second area are superposed in a registerable manner (see FIG. 4). A full-color castle image can be displayed by superimposing yellow (Y), cyan (C), green (G), magenta (M), and black (K) monochrome images. In this multicolor image, a black (K) opaque single-color image is arranged on the uppermost surface, and therefore, this portion exhibits a bright black color.

  And when this image display body was observed from the front, as shown in FIG. 5, the multicolor image of a very natural castle was able to be seen. Even when the observation angle was changed a little, the natural impression did not change. However, when the viewing angle was changed greatly, the color of the green color portion (for example, a tree portion) occupying a large area in the image changed greatly, resulting in an image with a very unnatural impression.

Claims (7)

In an image display body that displays a multicolor image by superimposing a plurality of single color images showing different colors,
Among the plurality of monochromatic images, a part of the monochromatic image is composed of a diffraction grating, and the color is indicated by diffracted light generated from the diffraction grating,
The monochromatic image showing other colors is a monochromatic image colored with a colorant,
An image display body characterized by that.   The image display body according to claim 1, wherein each of the plurality of monochrome images is a monochrome image obtained by color-separating the multicolor image.   3. The image display body according to claim 1, wherein the monochromatic image composed of the diffraction grating shows a color selected from colors constituting the light spectrum.   The image display body according to any one of claims 1 to 3, wherein the single-color image colored by the colorant shows a color selected from the three primary colors.   The image display body according to any one of claims 1 to 3, wherein the single color image colored with the colorant shows black. A base sheet and a transparent sheet are formed, and each of the base sheet and the transparent sheet is formed with a single-color image or a multi-color image in which a single-color image is superimposed. In an image display body that displays a multicolored image superimposed,
Among the monochromatic images constituting the monochromatic image or the multicolor image, a part of the monochromatic image is composed of a diffraction grating, and the color is shown by diffracted light generated from the diffraction grating,
The other image is a monochromatic image colored with a colorant.
An image display body characterized by that. A transparent sheet is divided into a plurality of areas via a fold line, and each of the plurality of areas is formed with a single color image or a multi-color image in which a single color image is superimposed, folded from the fold line, In an image display for displaying a multicolor image by superimposing a plurality of the single color images on each other,
Among the monochromatic images constituting the monochromatic image or the multicolor image, a part of the monochromatic image is composed of a diffraction grating, and the color is shown by diffracted light generated from the diffraction grating,
The other image is a monochromatic image colored with a colorant.
An image display body characterized by that.