Display member, method for producing display member, and method for verifying authenticity of display member

Abstract

To provide a display body resistant to both alteration and forgery.SOLUTION: According to one embodiment, a display for displaying an image in color includes a color-line group in which color lines of a plurality of colors for realizing color display of the image are periodically arranged to form a line pattern, and a plurality of concealing portions for concealing some of the color lines in the color-line group, wherein an outer diameter of each of the concealing portions is smaller than a line width of each of the color lines.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a display medium used as a personal authentication medium such as a passport or ID card, a method for producing the display medium, and a method for verifying the authenticity of the display medium. [Background technology]

[0002] It is important to prevent the forgery and alteration of personal authentication media such as passports and ID cards. In particular, personal authentication media that have been altered by replacing the face photo of a stolen item with that of another person are easy to manufacture and difficult to distinguish, because the rest of the device is genuine, so preventing this is a challenge.

[0003] In contrast to this, in recent years, the recording of personal information by laser writing on a polycarbonate substrate has become widely used. With this method, the inside of the substrate itself is darkened by the energy of the laser, which makes it difficult to remove later, unlike printing, and thus prevents falsification.

[0004] However, in the case of laser printing, the facial photograph is a monochrome image, which has the disadvantage that the information about appearance is inferior compared to the color digital facial photograph printing that has been the mainstream until now.

[0005] Therefore, in recent years, a technology has been put into practical use as a means of achieving both the anti-falsification effect of laser drawing and the colorization of facial images. This involves printing a CMY line pattern inside a polycarbonate base material in advance, and then using a laser to draw black to conceal part of the line pattern, thereby expressing color. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2012 / 069536 [Patent Document 2] International Publication No. 2012 / 069547 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the current line width of CMY line printing is about 60 μm to 100 μm, and the resolution is so low that the lines can be seen with the naked eye. Also, the principle of color expression is simple, so it is possible to create images that express color using the same principle using a computer.

[0008] By printing this image directly using a commercially available inkjet printer or the like, it becomes easy to create counterfeit products with a similar appearance.

[0009] Naturally, these counterfeits differ from the genuine products in many ways, but they are similar in terms of the reproduction of the facial photograph. Furthermore, since the genuine product itself is very distinctive and different from a typical facial photograph, any counterfeit that imitates this will likely be mistaken for the genuine product.

[0010] In other words, the method of printing CMY lines inside the polycarbonate base material in advance and then concealing them with laser drawing is resistant to alteration but vulnerable to counterfeiting.

[0011] The present invention has been made in view of the above circumstances, and aims to provide a display that is resistant to alteration and counterfeiting, a method for producing the same, and a method for verifying the authenticity of a display that can easily verify the authenticity of the display. [Means for solving the problem]

[0012] A first aspect of the present invention is a display device that displays an image in color, comprising a group of color lines in which each color line consisting of a plurality of colors that realize the color display of the image is periodically arranged to form a line array, and a plurality of concealing portions that conceal some of the color lines in the group of color lines, and the outer diameter of each concealing portion is smaller than the line width of the color line (for example, 1 / 2 or less).

[0013] A second aspect of the present invention is a display device according to the first aspect, in which the concealing portions are arranged in one or more rows, continuously or discretely along the length of any color line, so as to conceal at least a portion of the color line.

[0014] A third aspect of the present invention is the display of the second aspect, in which the arrangement density of the concealing portions along the length direction in each row is arbitrary.

[0015] A fourth aspect of the present invention is a display device according to the second aspect, further comprising a coloring layer in which the portion irradiated with laser light turns black and black dots are formed, and the concealing portion is a black dot formed in the coloring layer.

[0016] A fifth aspect of the present invention is the display of the first aspect, wherein the multiple colors include cyan, magenta, and yellow.

[0017] A sixth aspect of the present invention is the display device of the first aspect, wherein the multiple colors include multiple spot colors.

[0018] A seventh aspect of the present invention is the display according to the fourth or fifth aspect, wherein the plurality of colors further includes white.

[0019] An eighth aspect of the present invention is the display of the first aspect, wherein the color lines all have the same line width.

[0020] A ninth aspect of the present invention is the display of the first aspect, wherein the line width of any one of the color lines is different from the line width of the other color lines.

[0021] A tenth aspect of the present invention is the display device of the first aspect, wherein each of the color lines forming the parallel lines has a strip shape.

[0022] An eleventh aspect of the present invention is the display device according to the tenth aspect, wherein the strip has a rectangular shape.

[0023] A twelfth aspect of the present invention is the display device according to the tenth aspect, wherein at least a part of the strip has a wavy line shape.

[0024] A thirteenth aspect of the present invention is the display according to the tenth aspect, wherein at least a part of the strip has a shape of a broken line.

[0025] A fourteenth aspect of the present invention is a display device of the fourth aspect, in which, when black dots are arranged in multiple rows for multiple color lines of the same color, the black dots are arranged with the highest density in the row that is closest to the first direction (top) among the multiple color lines of the same color for the color line that is closest to the first direction (top), and the black dots are arranged with the highest density in the row that is closest to the second direction (bottom) among the multiple color lines of the same color, the first direction is perpendicular to the length direction and the second direction is opposite to the first direction.

[0026] A fifteenth aspect of the present invention is a display element of the fourth aspect, which is composed of a substrate, a printed layer including a group of color lines, and a color-developing layer laminated together, and the printed layer is located between the substrate and the color-developing layer, or the color-developing layer is located between the substrate and the printed layer.

[0027] A 16th aspect of the present invention is a method for verifying authenticity of a display body of the fourth aspect using a verifier, wherein the verifier is configured such that, when overlaid on the display body, concealing regions extending in the longitudinal direction that conceal rows of black dots and transparent regions extending in the longitudinal direction that transmit the rows of black dots are alternately arranged in a direction perpendicular to the longitudinal direction to form a line pattern, and the rows of black dots transmitted by each transparent region are at most one row in each color line of a specified color, and when the verifier is overlaid on the display body so that each transparent region corresponds to one row in each color line of a specified color, the authenticity verification method verifies the display body by a first image visualized by each row of black dots observed through each transparent region.

[0028] A 17th aspect of the present invention is a method for verifying authenticity of the 16th aspect, in which a display of the 14th aspect is verified using a verification device, and the method verifies the display using a first image and a second image that is visualized by one row of black dots observed through the transparent area when the display on which the verification device is superimposed is tilted from the state in which the first image is visualized.

[0029] An 18th aspect of the present invention is a method for verifying the display body of the fourth aspect using a verifier, wherein the black dots belong to either a first group of black dots arranged at a first period along the length direction in each of a plurality of columns corresponding to a specified color line, or a second group of black dots arranged at the first period so as to be shifted by 1 / 2 period from the first group of black dots, the verifier has a plurality of windows arranged at the first period along the length direction to allow the color of the specified color line to pass, and the verifier is superimposed on the display body so that the plurality of windows are arranged on the columns of the specified color line, and the verifier is verified along the length direction. When the display is moved in the direction of the arrow, a first display pattern is realized in which the color of the specified color line does not pass through windows blocked by black dots belonging to a first group of black dots among the multiple windows that are alternately displayed every half cycle, and the color of the specified color line passes through the other windows, and a second display pattern is realized in which the color of the specified color line does not pass through windows blocked by black dots belonging to a second group of black dots among the multiple windows, and the color of the specified color line passes through the other windows.

[0030] A 19th aspect of the present invention is a method for creating a display device that displays an image in color, comprising a printing layer and a coloring layer that, when irradiated with laser light, turns black in the irradiated portions, forming black dots, and includes the steps of: printing, on the printing layer by gravure offset printing, a group of color lines, each consisting of a plurality of colors used for the color display, that are periodically arranged to form a line array; and irradiating the coloring layer with laser light to form black dots that conceal part of the color lines.

[0031] A 20th aspect of the present invention is a display comprising a substrate, a group of color lines in which each color line is composed of a plurality of colors for displaying an image in color and is periodically arranged on the substrate so as to form a line array, and a transparent layer arranged on the substrate so as to cover the group of color lines, wherein a portion of the transparent layer is replaced by a non-transparent portion that conceals a portion of the color lines of the group of color lines, and the thickness of the non-transparent portion is equal to or greater than the line width of each color line.

[0032] A 21st aspect of the present invention is a display comprising a substrate, a plurality of groups of color lines, each consisting of a plurality of colors for displaying an image in color, arranged periodically on the substrate so as to form a line array, and a transparent layer arranged on the substrate so as to cover the plurality of groups of color lines, wherein a first length direction of the color lines of at least one of the plurality of groups of color lines is different from a second length direction of the color lines of the other groups of color lines, and a portion of the transparent layer is replaced by a non-transparent portion that conceals a portion of the color lines of each group of color lines, and the thickness of the non-transparent portion is greater than or equal to the line width of each of the color lines.

[0033] A 22nd aspect of the present invention is the display according to the 21st aspect, wherein the first length direction and the second length direction are perpendicular to each other.

[0034] A 23rd aspect of the present invention is the display of the 22nd aspect, wherein the display is polygonal in a two-dimensional plane perpendicular to the layer direction, and the first length direction is parallel to one side of the polygon.

[0035] A 24th aspect of the present invention is a display of the 22nd aspect, in which the display is polygonal in a two-dimensional plane perpendicular to the layer direction, and the first length direction is a direction at 45° to one side of the polygon.

[0036] A 25th aspect of the present invention is a display of the 20th or 21st aspect, in which the image appears as a first image to an observer observing under a first observation condition, and appears as a second image different from the first image to an observer observing under a second observation condition different from the first observation condition, and the first and second observation conditions differ in at least one of the rotation angle, which is the angle by which the display is rotated by the observer from a reference state in a two-dimensional plane, and the observation angle, which is the angle between the observer's line of sight toward the display and the surface of the display, and in the reference state, the rotation angle is zero.

[0037] A 26th aspect of the present invention is the display of the 20th or 21st aspect, wherein the transparent layer is color-developing and turns black when irradiated with laser light, and the non-transparent portion is a portion of the transparent layer that has turned black by irradiation with laser light.

[0038] A 27th aspect of the present invention is a method for verifying authenticity of a display object of the 25th aspect by confirming a changing effect in which a first image is visible when observed under a first observation condition, and a second image is visible when observed under a second observation condition.

[0039] A 28th aspect of the present invention is a display comprising a core layer, a color-forming layer laminated on the core layer and which develops color when irradiated with laser light, an intermediate transfer section laminated on the color-forming layer and on which a first image consisting of a predetermined color pattern is printed, and a second image different from the first image that is drawn by irradiating the color-forming layer with laser light to cause desired portions of the color-forming layer to develop color, and the second image obscures the first image so as to prevent light from the core layer side from entering the first image, thereby displaying the desired color image.

[0040] A 29th aspect of the present invention is a display device according to the 28th aspect, in which the first image is a group of color lines, each consisting of multiple colors that realize a color display, arranged periodically to form a line array.

[0041] A 30th aspect of the present invention is the display according to the 29th aspect, wherein the multiple colors include cyan, magenta, and yellow.

[0042] A thirty-first aspect of the present invention is the display according to the thirtieth aspect, wherein the plurality of colors further includes white.

[0043] A 32nd aspect of the present invention is the display according to the 28th aspect, wherein the predetermined color pattern is a one-dimensional color pattern.

[0044] A 33rd aspect of the present invention is the display according to the 28th aspect, wherein the predetermined color pattern is a two-dimensional color pattern.

[0045] A 34th aspect of the present invention is the display element of the 28th aspect, in which the printing of the first image is performed by a pigment indirect transfer method, in which a pigment ink ribbon is printed on an intermediate transfer film using a thermal head, and the printed intermediate transfer film is heat-fused to a color-developing layer to form an intermediate transfer section.

[0046] A thirty-fifth aspect of the present invention is the display according to the thirty-fourth aspect, wherein the intermediate transfer film includes a hologram.

[0047] A thirty-sixth aspect of the present invention is the display according to the thirty-fourth aspect, wherein the intermediate transfer film includes a metal vapor deposition layer that can be removed by laser light.

[0048] A 37th aspect of the present invention is the display device of the 28th aspect, wherein the first image is an outline of a photograph of the face of the owner of the display device.

[0049] A thirty-eighth aspect of the present invention is the display device of the twenty-eighth aspect, wherein the first image includes identification information of the owner of the display device.

[0050] A thirty-ninth aspect of the present invention is the display according to the thirty-fourth aspect, further comprising a transparent layer between the intermediate transfer film and the color-developing layer.

[0051] A fortieth aspect of the present invention is a method for creating a display element, which is created by preparing a core layer, laminating a color-forming layer on the core layer that develops color when irradiated with laser light, laminating an intermediate transfer part on which a first image consisting of a predetermined color pattern is printed on the color-forming layer, irradiating the color-forming layer with laser light to cause the color-forming layer to develop color in desired portions, and thereby drawing a second image different from the first image so as to prevent light from the core layer side from entering the first image.

[0052] A 41st aspect of the present invention is a production method according to the 40th aspect, in which the printing of the first image is carried out by a pigment indirect transfer method, in which a pigment ink ribbon is printed onto an intermediate transfer film using a thermal head, and the printed intermediate transfer film is heat-fused to a color-developing layer to form an intermediate transfer section. [Effects of the Invention]

[0053] According to the present invention, it is possible to provide a display that is resistant to alteration and counterfeiting, and a method for producing the same. It is also possible to provide a method for verifying the authenticity of a display that can easily verify the authenticity of the display. [Brief explanation of the drawings]

[0054] [Figure 1] FIG. 1 is a side cross-sectional view showing an example of the configuration of a display according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a partial plan view showing an example of a pattern-printed layer. [Figure 3] FIG. 3 is a partial plan view showing another example of the pattern-printed layer. [Figure 4] FIG. 4 is a partial cross-sectional side view showing the formation of black dots by irradiating a display with laser light. [Figure 5] FIG. 5 is a partial plan view of a display unit for explaining the principle of color display realized by laser drawing. [Figure 6] FIG. 6 is a plan view showing an example of a display body and a partially enlarged view of a pattern printed layer. [Figure 7]FIG. 7 is a partially enlarged plan view of the display, particularly including a part of the pattern printed layer in which black dots are irregularly arranged on one color line. [Figure 8] FIG. 8 is a partially enlarged plan view of the display, particularly including a part of the pattern printed layer in which the color lines are hidden by the black dots, and a side cross-sectional view of the display. [Figure 9] FIG. 9 is a side cross-sectional view showing a modified configuration example of the display according to the first embodiment. [Figure 10] FIG. 10 is a side cross-sectional view showing another modified configuration example of the display according to the first embodiment. [Figure 11] FIG. 11 is a side cross-sectional view showing another modified configuration example of the display according to the first embodiment. [Figure 12] FIG. 12 is a partially enlarged plan view of the display according to the first embodiment, particularly of the pattern-printed layer partially hidden by black dots. [Figure 13] FIG. 13 is a plan view showing an example of a verification device used in the first authentication verification method. [Figure 14] FIG. 14 is a plan view showing an example of a latent image displayed by a verifier. [Figure 15] FIG. 15 is a schematic diagram for explaining the second authentication verification method. [Figure 16] FIG. 16 is a partially enlarged plan view of the display according to the first embodiment, particularly of the pattern-printed layer partially hidden by black dots. [Figure 17] FIG. 17 is a plan view showing an example of a verification device used in the third authentication verification method. [Figure 18] FIG. 18 is a plan view showing a display pattern obtained from a display by a verifier. [Figure 19] FIG. 19 is a partially enlarged plan view of the display, particularly of the pattern printed layer in which the yellow color line is hidden by two rows of black dots. [Figure 20] FIG. 20 is a diagram showing an example of a face image in which a latent image is embedded. [Figure 21]FIG. 21 is a diagram showing an example of a latent image that is visualized when a verifier is placed over a display on which a face image is displayed. [Figure 22] FIG. 22 is a partial enlarged view showing a part of the number shown in FIG. 21, a partial enlarged view showing a part of the face image before it is visualized, and a plan view illustrating a verification device consisting of a line pattern. [Figure 23] FIG. 23 is a side cross-sectional view showing an example of the configuration of a display according to a second embodiment of the present invention. [Figure 24] FIG. 24 is a partial cross-sectional side view of FIG. 23, focusing on only the coloring or transparent layer, the pattern printed layer, and the coloring or transparent layer. [Figure 25] FIG. 25 is a plan view showing the pattern-printed layer before irradiation with laser light and the pattern-printed layer in which a part is concealed by a non-transparent part after irradiation with laser light. [Figure 26] FIG. 26 is a partial perspective view showing, in particular, the pattern printed layer and the color-developing layer when the display is tilted and observed from a different direction. [Figure 27] FIG. 27 is a partial cross-sectional side view showing, in particular, the pattern print layer and the color-developing layer of the display member according to this embodiment, for explaining the changing effect. [Figure 28] FIG. 28 is a partial cross-sectional side view showing, in particular, the pattern print layer and color-developing layer of the display member according to this embodiment, for explaining the changing effect. [Figure 29] FIG. 29 is a partial plan view of a pattern-printed layer that is not hidden by a non-transparent portion and a pattern-printed layer that is partially hidden by a non-transparent portion. [Figure 30] FIG. 30 is a partial side cross-sectional view showing the relationship between the thickness and the gap corresponding to FIG. 29(b), particularly showing the pattern printed layer and the coloring layer of the display member. [Figure 31] FIG. 31 is a partial side cross-sectional view showing the relationship between the thickness and the gap corresponding to FIG. 29(b), particularly showing the pattern printed layer and the coloring layer of the display member. [Figure 32]FIG. 32 is a partial plan view of a pattern-printed layer that is not concealed by a non-transparent portion and a pattern-printed layer that is partially concealed by a non-transparent portion. [Figure 33] FIG. 33 is a partial side cross-sectional view showing, in particular, the pattern print layer and coloring layer of the display element, for explaining how it appears when a non-transparent portion is formed above the color line. [Figure 34] FIG. 34 is a partial side cross-sectional view showing, in particular, the pattern print layer and the coloring layer of the display element, for explaining how it appears when a non-transparent portion is formed above the color line. [Figure 35] FIG. 35 is a partial plan view showing a pattern-printed layer provided with two types of pattern-printed portions. [Figure 36] FIG. 36 is a perspective view showing a state in which the display is tilted and observed along the y direction, and a state in which the display is rotated 90 degrees counterclockwise on the xy plane and observed along the x direction. [Figure 37] FIG. 37 is a partial plan view of a display body, particularly a pattern-printed layer provided with two types of periodic pattern-printed portions. [Figure 38] FIG. 38 is a diagram showing an example of the changing effect of the display body shown in FIG. [Figure 39] FIG. 39 is a diagram for explaining the changing effect of the display produced in this Example 2. In FIG. [Figure 40] FIG. 40 is a plan view showing an example of a printed matter on which a first pattern printed portion is printed. [Figure 41] FIG. 41 is a plan view showing an example of a printed matter on which a second pattern printed portion is printed. [Figure 42] FIG. 42 is a plan view showing an example of a printed matter formed by overlapping a first pattern-printed portion and a second pattern-printed portion. [Figure 43] FIG. 43 is a diagram showing an example of a face image formed on a card by laser drawing. [Figure 44] FIG. 44 is a side cross-sectional view showing an example of the configuration of a display according to the third embodiment before laser drawing. [Figure 45]FIG. 45 is a side cross-sectional view showing an example of the configuration of a display according to the third embodiment before and after laser drawing. [Figure 46] FIG. 46 is a plan view showing an example of a pattern used in the pattern printing layer. [Figure 47] This is an enlarged photograph of fine printing made by direct printing on a substrate with unevenness, and an enlarged photograph of fine printing made by indirect transfer on a sheet with minimal unevenness. [Figure 48] FIG. 48 is a partial cross-sectional side view showing an example of the configuration of a display member in which a transparent layer is provided between a pattern-printed layer and a color-developing layer. [Figure 49] FIG. 49 is a plan view showing the pattern-printed layer observed when the display shown in FIG. 48 is viewed from directly above. [Figure 50] FIG. 50 is a partial side cross-sectional view showing an example of the configuration of a display element in which there is no transparent layer between the pattern-printed layer and the color-developing layer. [Figure 51] FIG. 51 is a partial cross-sectional side view showing, in particular, the pattern-printed layer and the color-forming layer of a display member, for explaining the relationship between the line width of the color lines in the pattern-printed layer, the thickness of the color-forming layer, and the viewing direction. [Figure 52] FIG. 52 is a plan view showing an example of a pattern printing layer consisting of a line-type one-dimensional pattern of various colors. [Figure 53A] FIG. 53A is a diagram illustrating a display designed to display the letter "A." [Figure 53B] FIG. 53B is a diagram illustrating a display designed to display the letter "B." [Figure 54A] FIG. 54A is a perspective view of a display showing an example in which the color of the star-shaped figure and the color of its background change when viewed from different viewing angles. [Figure 54B] FIG. 54B is a plan view showing how a display such as that shown in FIG. 54A appears when observed from directly above. [Figure 55] FIG. 55 is a plan view showing an example of a created card on which an image has been printed. [Figure 56]FIG. 56 is a plan view showing an example of a card on which a non-transparent portion is formed in addition to the image shown in FIG. [Figure 57] FIG. 57 is a partial plan view of a display for explaining an example in which a predetermined color is concealed by laser drawing on a pattern-printed portion. [Figure 58] FIG. 58 is a plan view and a perspective view showing how the personal authentication medium appears. [Figure 59] FIG. 59 is a perspective view showing how the appearance of the personal authentication medium changes due to the changing effect. DETAILED DESCRIPTION OF THE INVENTION

[0055] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The drawings are schematic or conceptual, and the relationship between the thickness and line width of each part, the size ratio between parts, etc., are not necessarily the same as those in reality. Furthermore, even when the same part is shown, the dimensions and ratios may be different depending on the drawing. In this specification and each drawing, elements similar to those explained in the previous drawings are given the same reference numerals, and detailed and redundant explanations will be omitted as appropriate.

[0056] [First embodiment] A first embodiment of the present invention will be described.

[0057] (Example of display configuration) FIG. 1 is a side cross-sectional view showing an example of the configuration of a display according to a first embodiment of the present invention.

[0058] The display 10 according to the first embodiment is a display that displays an image in color, and includes, from the bottom in the figure, a core layer 11 that is a substrate, a pattern-printed layer 15 laminated on the core layer 11, a color-forming layer 13 laminated on the pattern-printed layer 15, and a transparent layer 14 laminated on the color-forming layer 13. Note that the color-forming layer 13 is laminated on the portion of the core layer 11 where the pattern-printed layer 15 is not laminated. These can be integrated by, for example, heat fusion, but may also be integrated by other methods.

[0059] The core layer 11 may be made of, for example, a white polycarbonate (hereinafter abbreviated as "PC") sheet.

[0060] The color-producing layer 13 may be a transparent PC sheet that turns black when irradiated with infrared laser light.

[0061] The transparent layer 14 may be a PC sheet that transmits infrared laser light.

[0062] Next, the pattern-printed layer 15 will be described.

[0063] FIG. 2 is a partial plan view showing an example of a pattern-printed layer.

[0064] FIG. 3 is a partial plan view showing another example of the pattern-printed layer.

[0065] 2(a), color lines of each of the multiple colors that realize a color display are periodically arranged to form a line consisting of a group of color lines in the pattern printing layer 15. For example, if the multiple colors that realize a color display are CMY (cyan, magenta, yellow), color lines C, M, Y of cyan, magenta, and yellow are periodically arranged to form a line consisting of a group of CMY color lines.

[0066] In offset printing, the line width of each color line in a CMY line pattern such as the one shown in Figure 2(a) is generally 60 to 100 μm. However, by using a special printing method such as gravure offset printing, it is possible to print a line pattern in which each color line has a line width of 10 to 50 μm.

[0067] The number of types of multiple colors is not limited to three. FIG. 2(b) illustrates a line pattern using white in addition to cyan, magenta, and yellow. In FIG. 2(b), color line W indicates a white line. The white line W can be realized by providing an unprinted area between the repetitions of C, M, Y, and W. In this way, a line pattern can be formed consisting of a group of C, M, Y, and W color lines, each of which is periodically arranged.

[0068] In the example shown in FIG. 2(a), the lines are illustrated as strips extending in the y direction. In this case, the length direction of each color line is the y direction. The shape of the strips is not limited to the rectangular shape shown in FIG. 2(a), but may be a curved shape such as a wavy line as shown in FIG. 2(d). Furthermore, as shown in FIG. 2(e), the strips may be a broken line. Whether the lines are a curved shape such as a wavy line as shown in FIG. 2(d) or a broken line as shown in FIG. 2(e), the length direction of the color line can be considered to be the y direction as long as the lines are directed in the y direction as a whole. Furthermore, it is not necessary for a strip to have the same shape or the same pattern from beginning to end. For example, only a portion of a rectangular strip may be a wavy line or a broken line.

[0069] Although Figures 2(a), 2(b), 2(d), and 2(e) show examples in which the line widths of each color line are the same, the line widths of each color line may be different, and a line pattern can be created in which the line widths of each color are adjusted as desired. For example, Figure 2(c) shows an example in which the line width of the yellow line Y is twice that of the other color lines. Adjusting the line widths of each color in the line pattern can further improve the reproducibility of color images. The applicant has successfully created a CMYY line pattern, such as the one shown in Figure 2(c), in which the line width of the cyan line C is 20 μm, the line width of the magenta line M is 20 μm, and the line width of the yellow line Y is 40 μm. At present, no printed line pattern with such a fine level of detail is available on the market.

[0070] The multiple colors used to realize a color display are not limited to CMY, but may also be RGB, or may be special colors, as shown in FIG.

[0071] Figure 3(a) illustrates a line pattern consisting of three spot color lines T1, T2, and T3, plus a white color line W. Figure 3(b) illustrates a line pattern consisting of two spot color lines T1 and T2, plus a white color line W.

[0072] The images displayed in color by the display 10 can include logos, national flags, emblems, text information, and the like, but in most cases, they are photographs of faces. To improve the reproducibility of facial colors, it is preferable to use spot colors rather than CMY process colors. For example, using at least one spot color specifically tailored to facial colors can improve color reproducibility compared to pattern printing composed of CMY. Furthermore, by limiting the color image to a photograph of a face, a pattern using two spot colors in addition to white can be used, as illustrated in FIG. 3(b), rather than a pattern using three spot colors in addition to white, as illustrated in FIG. 3(a). This reduces the pixel area required to create one color, thereby increasing image resolution.

[0073] The display 10 having the above-described layer structure is irradiated with laser light L to form black dots in the color-producing layer 13.

[0074] FIG. 4 is a partial cross-sectional side view showing how black dots K are formed in the color-producing layer 13 by irradiating the display 10 with laser light L from the laser drawing device 20. As shown in FIG.

[0075] As shown in Figure 4, when the display body 10 is irradiated with laser light L from the laser drawing device 20, black dots K are formed in the color-forming layer 13. The black dots K serve as concealing portions that conceal all or part of the designated color lines in the pattern-printed layer 15 located below in Figure 4. In other words, where the black dots K are present, the reflected light from the core layer 11 cannot pass through the color lines. This is called concealment.

[0076] In this way, by hiding a part of the color line by laser drawing, more flexible color adjustment becomes possible. The principle behind this will be explained below.

[0077] FIG. 5 is a partial plan view of a display unit for explaining the principle of color display realized by laser drawing.

[0078] FIG. 6 is a plan view showing an example of a display body and a partially enlarged view of a pattern printed layer.

[0079] The pattern-printed layer 15 illustrated in FIG. 5(a) corresponds to a part of the pattern-printed layer 15 included in the display 10, as shown in FIG.

[0080] FIG. 5(a) is a plan view of the pattern printed layer 15 having the same line pattern as in FIG. 2(b), and the display 10 has not yet been irradiated with the laser light L. FIG.

[0081] 5(b) is a partial plan view of the display member 10 in which black dots K have been formed in the color-forming layer 13 by irradiation with laser light L. The color lines C and Y in the pattern-printed layer 15 are hidden by the black dots K. This state is achieved by irradiating the color-forming layer 13 with laser light L from the laser drawing device 20 onto the areas directly above the color lines C and Y, forming black dots K there, as shown in FIG. 4. As a result, the cyan color lines C and the yellow color lines Y are hidden, and only magenta is displayed.

[0082] Fig. 5(c) is a plan view showing a part of the display member 10 in which the color lines M and Y in the pattern-printed layer 15 are hidden by black dots K formed in the color-forming layer 13 by irradiation with laser light L. The state shown in Fig. 5(c) is achieved by irradiating the areas directly above the color lines M and Y in the color-forming layer 13 with laser light L from the laser drawing device 20, as illustrated in Fig. 4, to form black dots K there. In this case, the magenta color lines M and the yellow color lines Y are hidden, so only cyan is displayed.

[0083] In this way, by hiding color lines other than the color desired to be displayed in the pattern-printed layer 15 with black dots K, it is possible to realize any desired color expression.

[0084] 5(b) and 5(c) show an example in which the entire color width of a color line is concealed by black dots K. In this way, in order to conceal the entire color width with black dots K, the spot diameter of the laser light L needs to be equal to or smaller than the line width of the color line. If the spot diameter of the laser light L is approximately the same as the line width of the color line, it is possible to form black dots K that conceal an entire color width in one scan by irradiating the laser light L while scanning the laser drawing device 20 along the y direction.

[0085] On the other hand, if the spot diameter of the laser light L is smaller than the width of the color line, it is necessary to perform the process of forming the black dots K while scanning the laser drawing device 20 along the y direction multiple times by changing the position in the x direction. For example, if the spot diameter of the laser light L is half the width of the color line, two scans are required to form the black dots K that cover the entire width of one color line.

[0086] 5(d) shows an example in which a laser beam L with a spot diameter approximately equal to the width of the color line is used to conceal the entire color width of the magenta color line M, and a laser beam L with a spot diameter smaller than the width of the color line is used to conceal the yellow color line Y with black dots K, but not entirely, over a portion of the color width. In this way, the black dots K may be arranged discretely rather than continuously along the length of the color line. Furthermore, the black dots K may be arranged at a constant or variable density along the length of the color line.

[0087] Mixing cyan and yellow produces green. In the case of Figure 5(d), the contribution of yellow is halved, so a slightly greenish cyan can be produced.

[0088] In this way, detailed color expression of the image is possible by selecting which color lines are concealed by the black dots K, at what ratio, and in what pattern. Also, the black dots K may be arranged irregularly for the same color line. This allows for a wider variety of color expression.

[0089] An example of black dots K irregularly arranged in the color-forming layer 13 relative to the color lines of the pattern-printed layer 15 will be described below.

[0090] FIG. 7 is a partially enlarged plan view of the display, particularly including a part of the pattern printed layer in which black dots are irregularly arranged on one color line.

[0091] Figure 7 illustrates a display 10 in which black dots K are irregularly arranged in the color-forming layer 13 for one color line of the pattern-printed layer 15. In all of Figures 7(a), (b), and (c), the pattern-printed layer 15 consists of a cyan color line C, a magenta color line M, and a yellow color line Y. In Figures 7(a) and (b), the line widths of each color line are the same, approximately 60 μm. In Figure 7(c), the line widths of the color lines C and M are approximately 20 μm, which is about one-third of the line widths in Figures 7(a) and (b), and the line width of the color line Y is twice that, approximately 40 μm.

[0092] 7(a), in a display 10 in which a specific color line of the pattern-printed layer 15 is concealed, black dots K that conceal color line C are discretely arranged in the pattern-printed layer 15 along the y direction, which is the length direction of the color line, at positions corresponding to the center of the color width of color line C. Black dots K that conceal color line Y are also discretely arranged along the y direction at positions corresponding to the center of the color width of color line Y, but the arrangement density is lower than that of the black dots K that conceal color line C.

[0093] In the display 10 shown in Fig. 7(b), the black dots K that conceal the color line Y of the pattern-printed layer 15 are formed by laser light L with a spot diameter that is approximately 1 / 3 of the laser light L used in Fig. 7(a). Therefore, the color line Y can be concealed by three rows of black dots K.

[0094] In the pattern-printed layer 15 shown in Figure 7(c), the black dots K1 that conceal the color line C are arranged discretely in a row. Also, the color line Y, which has twice the line width of the color lines C and M, is concealed by two rows of black dots K1 and K2. Of the two rows of black dots that conceal the color line Y, the black dots K1 in the first row are the same size as the black dots K1 that conceal the color line C, and the black dots K2 in the second row have a dot diameter slightly larger than the black dots K1.

[0095] In this way, the display element 10 of this embodiment is produced by the steps of printing a group of color lines, which are periodically arranged so that each color line forms a line pattern, on the pattern printing layer 15 by gravure offset printing, photographing the entire printed pattern printing layer 15, extracting position data of all the lines and calculating appropriate correction values, and irradiating the color-producing layer 13 with laser light L while moving the galvanometer mirror in accordance with the input correction values, thereby forming black dots K that conceal part of the color lines.

[0096] Since multiple types of black dots K with different diameters can be formed on the display 10 produced by this production method, it is also possible to embed predetermined information by adjusting the relative position of the black dots K with respect to the color lines. This will be explained using FIG. 8.

[0097] 8A and 8B are a partially enlarged plan view of the display body, particularly including a part of the pattern-printed layer in which the color lines are hidden by black dots, and a side cross-sectional view of the display body. In particular, Fig. 8A is a partial plan view of the display body 10 showing the state in which the color lines of the pattern-printed layer 15 are hidden by black dots K, and Fig. 8B is a side cross-sectional view of the display body 10 corresponding to Fig. 8A.

[0098] In the example shown in FIG. 8(a), a black dot K conceals a cyan color line C. C are positioned so as to be located on the center line of the color line C, but of the black dots Ky that conceal the yellow color line Y, the black dot Ky1 that conceals the color line Y1 is located toward the top, or the upper side, in the figure, and the black dot Ky2 that conceals the color line Y2 is located toward the bottom, or the lower side, in the figure.

[0099] If an observer simply views such a display 10, the color lines Y1 and Y2 cannot recognize the difference in color tone because they are covered by the black dots K by the same area, and as a result, they appear to be the same. However, by enlarging the display 10 or using an authenticity verification method described below, it becomes possible to confirm the difference in the arrangement of the black dots K. Therefore, it is possible to determine the authenticity of the display 10 based on the arrangement pattern of the black dots K as shown in FIG. 8. Details of the authenticity verification method will be described later.

[0100] (Example of display deformation configuration) Next, a modified configuration example of the display according to the first embodiment will be described.

[0101] FIG. 9 is a side cross-sectional view showing a modified configuration example of the display according to the first embodiment.

[0102] 9(a) shows the state before the black dots K are formed, and FIG. 9(b) shows the state after the black dots K are formed. The display body 10A shown in FIG. 9(a) differs from the display body 10 in that it has a transparent layer 12 between the pattern-printed layer 15 and the color-forming layer 13. In the area where the pattern-printed layer 15 is not present, the transparent layer 12 is laminated on the core layer 11.

[0103] In the layer configuration shown in Fig. 1, when black dots K are formed in the color-forming layer 13 by irradiating it with laser light L, there is a possibility that peeling will occur at the interface between the printing ink used in the pattern-printed layer 15 and the core layer 11 due to the influence of volume fluctuations in the color-forming layer 13. To prevent this, in the display member 10A exemplified in Fig. 9(a), a transparent layer 12 is provided to physically separate the pattern-printed layer 15 where the printing ink is present from the color-forming layer 13 where the black dots K are formed, thereby preventing the above-mentioned peeling.

[0104] FIG. 10 is a side cross-sectional view showing another modified configuration example of the display according to the first embodiment.

[0105] Fig. 10(a) shows the state before the black dots K are formed, and Fig. 10(b) shows the state after the black dots K are formed. The display member 10B illustrated in Fig. 10(a) differs from the display member 10 in that, as shown from below in the figure, a color-forming layer 13 is laminated on a core layer 11, a pattern-printed layer 15 is laminated on the color-forming layer 13, and a transparent layer 14 is laminated on the pattern-printed layer 15. In areas where the pattern-printed layer 15 is not present, the transparent layer 14 is laminated on the color-forming layer 13.

[0106] When a laser beam L is irradiated onto a display 10B having the configuration illustrated in FIG. 10(a), black dots K are formed below the pattern-printed layer 15, as illustrated in FIG. 10(b).

[0107] Even in the display member 10B configured as described above, the printing ink of the pattern printed layer 15 and the black dots K, which are the colored portions of the color-producing layer 13, can be physically separated, so that the peeling described above can be prevented.

[0108] FIG. 11 is a side cross-sectional view showing another modified configuration example of the display according to the first embodiment.

[0109] Fig. 11(a) shows the state before the black dots K are formed, and Fig. 11(b) shows the state after the black dots K are formed. The display body 10C shown in Fig. 11(a) differs from the display body 10 in that, as shown from below in the figure, a color-forming layer 13 is laminated on a core layer 11, a transparent layer 12 is laminated on the color-forming layer 13, a pattern-printed layer 15 is laminated on the transparent layer 12, and a transparent layer 14 is laminated on the pattern-printed layer 15. In areas where the pattern-printed layer 15 is not present, the transparent layer 14 is laminated on the color-forming layer 12.

[0110] When a laser beam L is irradiated onto a display 10C having the configuration illustrated in FIG. 11(a), black dots K are formed below the pattern-printed layer 15, as illustrated in FIG. 11(b).

[0111] Even in the display member 10C having such a configuration, the printing ink of the pattern printed layer 15 and the black dots K, which are the colored portions of the color-forming layer 13, can be physically separated, so that the peeling described above can be prevented.

[0112] (First method for verifying authenticity of display body) Next, a first method for verifying authenticity of a display medium according to the first embodiment will be described.

[0113] FIG. 12 is a partially enlarged plan view of the display according to the first embodiment, particularly of the pattern-printed layer partially hidden by black dots.

[0114] FIG. 13 is a plan view showing an example of a verification device used in the first authentication verification method.

[0115] FIG. 14 is a plan view showing an example of a latent image displayed by a verifier.

[0116] In the first authentication verification method, the display medium 10 is verified by placing a verifier 30 on the transparent layer 14 of the display medium 10 .

[0117] 13, the verifier 30 is configured by strip-shaped hidden regions 32 and transparent regions 31, both of which extend in the y direction in the figure, being alternately arranged in the x direction to form a line pattern. Such a verifier 30 can be realized in the form of a transparent film having black hidden regions 32 and white transparent regions 31, and can be produced, for example, by printing black hidden regions 32 on a transparent sheet.

[0118] The concealing region 32 conceals the row of black dots K when the verifier 30 is superimposed on the transparent layer 14 of the display 10 .

[0119] The transparent region 31 does not conceal the row of black dots K when the verifier 30 is superimposed on the transparent layer 14 of the display 10. Therefore, if the black dots K are above a transparent region 31, they will be transparent through the transparent region 31. Therefore, each transparent region 31 can transmit one row of black dots K in each color line of a specified color (for example, color line Y or color line M).

[0120] The verifier 30 having such a configuration is superimposed on the transparent layer 14 of the display body 10 so that each transmissive region 31 corresponds to one of the rows of color lines of the specified color, and the length direction of each transmissive region 31 corresponds to the line direction of the pattern printed layer 15. When the display body 10 is observed from the front side in this state, a latent image formed by each row of black dots that have passed through each transmissive region 31 is visualized.

[0121] For example, an example in which the display 10 illustrated in FIG. 12 is verified using the verification device 30 will be described.

[0122] In the display 10 illustrated in FIG. 12, two rows of black dots K are provided for each of the color lines Y and M.

[0123] 14(a) shows a state in which the verifier 30 is superimposed on the display 10 illustrated in FIG. 12 so that each transmissive region 31 is aligned with the lower row of black dots K for each color line Y. In this state, the black dots K in the lower row for each color line Y are transparent to the transmissive region 31, while the other black dots K are hidden by the hidden region 32. Therefore, the latent image (dot pattern) of the black dots K in the lower row for each color line Y that have passed through the transmissive region 31 is visualized. In this way, predetermined information (e.g., a graphic pattern) embedded as a latent image by the lower row of black dots K for each color line Y can be extracted.

[0124] 14(b) shows a state in which the verifier 30 is superimposed on the display 10 illustrated in FIG. 12 so that each transparent region 31 is aligned with the upper row of black dots K for each color line M. In this state, the black dots K in the upper row for each color line M are transparent to the transparent region 31, while the other black dots K are hidden by the hidden region 32. Therefore, the latent image (dot pattern) formed by the black dots K in the upper row for each color line M that have passed through the transparent region 31 is visualized. In this way, predetermined information (e.g., a graphic pattern) embedded as a latent image by the black dots K in the lower row for each color line M can be extracted.

[0125] By verifying that the image visualized in this way is correct information (for example, a correct figure), the authenticity of the display 10 can be determined.

[0126] In this way, by providing multiple rows of black dots K for each color line, the display 10 can embed multiple pieces of verification information without changing the overall color tone or density, as shown in Fig. 12. As described above, this information can be extracted by superimposing a verifier 30 consisting of a simple line pattern on the display 10, as shown in Fig. 13.

[0127] The verifier 30 can be produced not only by printing as described above, but also by removing a transparent sheet having a metal deposition layer with a laser or the like to form equally spaced transparent regions 31.

[0128] Also, a lenticular lens can be used instead of the line pattern. In this case, it is desirable that the pitch of the lenticular lens is the same as the printing pitch of the lines (for example, the width of the color lines) or an integer multiple thereof. In the case of a verifier 30 using a lenticular lens, the verifier 30 is used by superimposing it on the display 10 so that the array direction of the lenticular lens coincides with an example of the black dots K.

[0129] (Second method for verifying authenticity of display body) Next, a second method for verifying authenticity of the display according to the first embodiment will be described.

[0130] FIG. 15 is a schematic diagram for explaining the second authentication verification method.

[0131] The second authenticity verification method is realized by having the viewer S tilt and observe the display 10 on which the verifier 30 is superimposed, as described in the first authenticity verification method. To perform this observation, the verifier 30 may be fixed in advance to the top surface of the display 10 (the surface on the viewer S side in FIG. 15).

[0132] FIG. 15(a) shows a side cross-sectional view of a display body 10 in which a verifier 30 is fixed to a transparent layer 14, and an observer S observing the upper surface of the display body 10 from directly above.

[0133] The observer S observes the black dots K that have passed through the transmissive region 31. H indicates the line of sight from the black dots K to the observer S.

[0134] In the example shown in FIG. 15(a), two rows of black dots K on the top side of the display 10, which corresponds to the left side of the figure, are observed by the observer S through the transmissive region 31. These two rows of black dots K on the top side are located above the color line Y in the color-producing layer 13, and therefore appear as dark yellow to the observer S. On the other hand, the two rows of black dots K on the bottom side of the display 10, which corresponds to the right side of the figure, are hidden by the concealing region 32 and are therefore invisible to the observer S.

[0135] FIG. 15(b) shows a side cross-sectional view of the display 10 shown in FIG. 15(a) tilted with the top side facing up and the bottom side facing down, and the positional relationship with the viewer S.

[0136] In the example shown in FIG. 15(b), the two rows of black dots K on the top side of the display 10 are hidden by the concealing region 32 and therefore cannot be seen by the viewer S. On the other hand, the two rows of black dots K on the bottom side of the display 10 can be seen by the viewer S through the transmissive region 31. As shown in FIG. 15(a), the two rows of black dots K on the bottom side of the display 10 are located above the color line Y in the color-producing layer 13. However, when the display 10 is tilted as shown in FIG. 15(b), the black dots K appear to be located above the color line C and therefore appear as dark cyan to the viewer S.

[0137] In this way, by tilting and observing the display 10, a changing effect occurs in which the latent image that appeared disappears and another latent image appears. Therefore, by observing the appearance of the correct image through the changing, it becomes possible to verify the authenticity of the display 10.

[0138] In particular, as shown in Figure 2(d), by making the shape of the strips of lines wavy, it is possible to realize partial color changes and special appearances. In this case, it is also possible to embed information in the lines by, for example, setting the frequency of the waves of the wavy lines to a frequency obtained by Fourier transforming certain information.

[0139] In particular, as shown in Figure 2(e), by making the shape of the strips of lines into a broken line shape and further designing the angle of the broken line appropriately, it is possible to achieve a changing effect in which the color changes depending on the viewing direction.

[0140] (Third method for verifying authenticity of display objects) Next, a third method for verifying authenticity of the display medium according to the first embodiment will be described.

[0141] FIG. 16 is a partially enlarged plan view of the display according to the first embodiment, particularly of the pattern-printed layer partially hidden by black dots.

[0142] FIG. 17 is a plan view showing an example of a verification device used in the third authentication verification method.

[0143] FIG. 18 is a plan view showing a display pattern obtained from a display by a verifier.

[0144] In the first authentication verification method described above, an example was described in which the authenticity of the display medium 10 is verified using information (latent image) embedded by adjusting the position of the black dots K in the width direction (x direction) of the color lines of the display medium 10. In this authenticity verification method, the display medium 10 is verified using more complex information (latent image) embedded by adjusting the position of the black dots K not only in the width direction (x direction) of the color lines of the display medium 10 but also in the length direction (y direction).

[0145] 16, a single row of black dots K is provided in the y direction above the color line M (the front side in the figure), and two rows of black dots K are provided in the y direction above the color line Y. The two rows of black dots K on the color line Y realize four patterns. In other words, four pieces of information can be embedded by the two rows of black dots K on the color line Y.

[0146] That is, the black dots K arranged above the color line Y belong to either a first group of black dots arranged at a constant period P along the length direction (y direction) in each of the two columns, or a second group of black dots arranged at the same period P but shifted by 1 / 2 period (i.e., P / 2 period) from the first group of black dots.

[0147] 16, in the first row of black dots K arranged above the color line Y, those belonging to the first group of black dots are indicated by black dot K2, and those belonging to the second group of black dots are indicated by black dot K3. That is, both the black dots K2 and K3 are arranged at the same period P, but the black dots K2 and K3 can be arranged with a half-period shift so that they do not coincide.

[0148] In the second row, the black dots belonging to the first group are black dots K4, and the black dots belonging to the second group are black dots K5. That is, both black dots K4 and K5 are arranged at the same period P, but black dots K2 and K3 can be arranged with a half-period shift so that they do not coincide.

[0149] By arranging two types of black dots K in each row in this way, when black dots K are arranged in two rows above the color line, there will be four types of black dots K, and these four types of black dots K2 to K5 make it possible to embed four latent images, i.e., four pieces of information, in the display 10.

[0150] Of course, these four types of black dots K2 to K5 cannot be distinguished visually, and since they are all the same black color, it is impossible to recognize the four types of information contained therein even when they are enlarged and displayed.

[0151] However, in this authenticity verification method, by using a verifier 35 as shown in Figure 17, black dots belonging to the same group of black dots can be selectively extracted from the black dots K2 to K5, such as only black dot K2, only black dot K3, only black dot K4, and only black dot K5, as described below, and four latent images, i.e., four types of information, can be obtained.

[0152] The verifier 35 is configured by opening a plurality of windows 37 in a light-shielding portion 36. The plurality of windows 37 are opened and provided in the light-shielding portion 36 along the length direction (y direction) at the same period P as the period P described above.

[0153] When such a verifier 35 is superimposed on the display body 10 so that the window 37 is positioned on a row (e.g., the first row) of a specified color line (e.g., color line Y) and moved in the longitudinal direction (y direction), two types of display patterns (Figures 18(a) and (b)) are alternately displayed from the verifier 35 each time the verifier 35 is moved 1 / 2 cycle in the longitudinal direction (y direction).

[0154] Figure 18(a) shows a display pattern that is realized when yellow, the color of color line Y, does not pass through windows 37 blocked by black dot K2 belonging to the first group of black dots in the first column among the multiple windows 37 of the verifier 35, but passes through the other windows 37.

[0155] Figure 18(b) shows a display pattern that is realized when yellow, the color of color line Y, does not pass through windows 37 blocked by black dot K3 belonging to the second group of black dots in the first column among the multiple windows 37 of the verifier 35, but passes through the other windows 37.

[0156] Figure 18(c) shows a display pattern that is realized when yellow, the color of color line Y, does not pass through windows 37 blocked by black dot K4 belonging to the first group of black dots in the second column among the multiple windows 37 of the verifier 35, but passes through the other windows 37.

[0157] Figure 18(d) shows a display pattern that is realized when yellow, the color of color line Y, does not pass through windows 37 blocked by black dot K5 belonging to the second group of black dots in the second column among the multiple windows 37 of the verifier 35, but passes through the other windows.

[0158] As described above, instead of obtaining such a display pattern by superimposing the verifier 35 on the display 10, it is also possible to obtain such a display pattern by taking an image of the display 10 using a mobile device with a camera, such as a smartphone, and applying an appropriate filter (for example, a filter similar to that of the verifier 35) during image processing.

[0159] (Action and effect) As described above, according to this embodiment, by applying a special printing method such as gravure offset printing, the line width of each color line in the pattern printing layer 15 of the display body 10 can be made finer, from the conventionally common 60 μm to 10 to 20 μm.

[0160] Furthermore, by using a laser drawing device 20 that emits laser light L with a spot diameter of approximately 20 μm, which is smaller than the conventionally common spot diameter of approximately 60 μm, more precise laser drawing can be performed on the display body 10 with a high drawing accuracy of approximately ±2 μm.

[0161] Therefore, it is possible to draw special patterns with high precision, and it is possible to embed a latent image that cannot be recognized by the naked eye in the display 10 while improving the resolution of the image displayed on the display 10. This makes the display 10 according to this embodiment more difficult to copy, and improves counterfeit resistance.

[0162] Furthermore, the authenticity of the display 10 according to this embodiment can be easily determined using a verification device or, for example, a smartphone app.

[0163] As described above, according to this embodiment, it is possible to create a display medium that is difficult to counterfeit or alter and that is easy to verify authenticity. It is also possible to provide an authenticity verification method that enables such easy authentication.

[0164] Example 1 Next, Example 1, in which a display according to this embodiment was actually manufactured, will be described.

[0165] (Printing CMY line patterns for displays) First, to print the CMY line pattern of the pattern printing layer 15 of the display 10, a gravure offset printing machine was used to print a line pattern consisting of three color lines C, M, and Y on a 100 μm thick sheet of color-forming layer 13 ("SL2000" manufactured by Mitsubishi Gas Chemical Company, Inc.). The line widths of the color lines were C: 20 μm, M: 20 μm, and Y: 40 μm. The color lines were 30 mm long and arranged horizontally, and were repeatedly arranged vertically in the order C, M, and Y 500 times with no gaps between them. This resulted in printing the pattern printing layer 15 consisting of a CMY line pattern measuring 30 mm wide and 40 mm long.

[0166] (Printing a line pattern for the verifier) Next, to print the line pattern for the verifier 30, the same gravure offset printing machine as that used to print the CMY line pattern of the pattern printing layer 15 was used to print the line pattern with black ink on a 100 μm thick PET sheet. The black ink line width was 40 μm and the length was 30 mm, with 40 μm intervals between the lines, and the black ink and interval arrangement was repeated 500 times to form the line pattern. This resulted in the creation of a verifier 30 in an area 30 mm wide and 40 mm long, with slit-shaped transparent areas 31 provided between hidden areas 32 at an 80 μm pitch.

[0167] (Creating a display) The sheet of the pattern-printed layer 15 printed above, the sheet of the core layer 11, and the sheet of the transparent layer 14 were laminated in this order and fused by heat pressing to create the display member 10. The heating conditions were 190°C for 7 minutes, and the cooling conditions were 20°C for 5 minutes. The pressure during heating and cooling was adjusted appropriately depending on the elapsed time so as not to destroy the line pattern printed on the pattern-printed layer 15.

[0168] The sheet used for the color-forming layer 13 was "SL2000" (thickness: 100 μm) manufactured by Mitsubishi Gas Chemical Co., Inc., the sheet used for the core layer 11 was "SW2000" (thickness: 100 μm) manufactured by Mitsubishi Gas Chemical Co., Inc., and the sheet used for the transparent layer 14 was "ST2000" (thickness: 100 μm) manufactured by Mitsubishi Gas Chemical Co., Inc.

[0169] (laser drawing) Next, the display 10 was irradiated with laser light L from the laser drawing device 20 to form black dots K in the color-producing layer 13. The laser drawing device 20 can draw with infrared laser light L having a spot diameter of 20 μm with a positional accuracy of 2 μm, and further, by adjusting the power of the laser light L, it is possible to form black dots K with a diameter of about 10 to 20 μm.

[0170] Furthermore, by providing the laser drawing device 20 with a CCD camera, it is possible to detect the edges of the pattern printing layer 15 and accurately draw at positions corresponding to predetermined positions in the printed line pattern.

[0171] Using a laser drawing device 20, drawing was performed on the color-developing layer 13 with laser light L so as to conceal the color lines C, M, and Y of the pattern-printed layer 15, and black dots K were formed, thereby forming a color portrait.

[0172] FIG. 19 is a partially enlarged plan view of the display, particularly of the pattern printed layer in which the yellow color line is hidden by two rows of black dots.

[0173] As shown in Figure 19, when concealing the yellow color line Y, a distinction is made between the top side (upper part in Figure 19) and the bottom side (lower part in Figure 19) of the 40 μm wide color line, and black dots K are usually drawn closer to the top side as shown in part 40, but in the area where a latent image is to be provided, they are drawn closer to the bottom side as shown in part 42. In this way, a facial image is formed in which a latent image that is not visible to the naked eye is embedded.

[0174] FIG. 20 is a diagram showing an example of a face image in which such a latent image is embedded.

[0175] A latent image is embedded in the facial image a shown in Fig. 20(a) by arranging black dots K. Details of the latent image will be described later with reference to Fig. 21 and Fig. 22. Fig. 20(b) is a partially enlarged view of the facial image shown in Fig. 20(a).

[0176] (verification) FIG. 21 is a diagram showing an example of a latent image that is visualized when a verifier is placed over a display on which a face image is displayed.

[0177] That is, Fig. 21 shows an example of a latent image obtained when the verifier 30 is superimposed on the surface of the display 10 on which the facial image a as shown in Fig. 20(a) is displayed. In Fig. 21, a star mark D is visualized on the forehead of the facial image a, and a number E is visualized on the chin as visualized latent images.

[0178] Figure 22 shows (a) a partially enlarged view showing a part of the number shown in Figure 21, (b) a partially enlarged view showing a part of the facial image before it is visualized, and (c) a plan view illustrating a verification device consisting of a line pattern.

[0179] That is, by superimposing the verifier 30 illustrated in FIG. 22(c) on the facial image a illustrated in FIG. 22(b), it was confirmed that the latent image (the numbers "123456789") embedded in the facial image a was visualized as illustrated in FIG. 22(a).

[0180] [Second embodiment] A second embodiment of the present invention will be described. Note that the contents already explained in the first embodiment will be explained in a simplified manner by assigning the same reference numerals to the same parts to avoid repetitive explanations.

[0181] (Example of display configuration) FIG. 23 is a side cross-sectional view showing an example of the configuration of a display according to a second embodiment of the present invention.

[0182] That is, the display 10D according to the second embodiment is a display that displays images in color, and is composed of, from the bottom in the drawing, a substrate 16, a core layer 11 made of PC, a colored or transparent layer 17 made of PC, a pattern printed layer 15, a colored or transparent layer 18 made of PC, and a transparent layer 14 made of PC. These can be integrated by, for example, heat fusion, but may also be integrated by other methods.

[0183] The color-developing or transparent layer 18 is disposed so as to cover the pattern-printed layer 15, and turns black when irradiated with laser light L. In the display member 10D according to this embodiment, the color-developing or transparent layer 18 can also be blackened using laser light L as described in the first embodiment. When a near-infrared laser is used as the laser light L, PC is suitable for the base material 16. On the other hand, when a short-wavelength laser is used as the laser light L, the base material 16 is not limited to PC.

[0184] FIG. 24 is a partial cross-sectional side view of FIG. 23, focusing on only the coloring or transparent layer 17, the pattern-printed layer 15, and the coloring or transparent layer 18. In FIG.

[0185] Fig. 24(a) shows the state before irradiation with laser light L, and Fig. 24(b) shows the state after irradiation with laser light L. When irradiated with laser light L, the portions of the colored or transparent layer 18 irradiated with laser light L turn black, becoming non-transparent portions 18K. Fig. 24(b) shows an example in which non-transparent portions 18K are formed above the color lines M and Y in the pattern-printed layer 15 (upper side in the figure).

[0186] 25A and 25B are plan views showing the display 10D as viewed from directly above, with FIG. 25A corresponding to the state before irradiation with laser light L and FIG. 25B corresponding to the state after irradiation with laser light L. FIG.

[0187] FIG. 25 is a plan view showing the pattern-printed layer before irradiation with laser light and the pattern-printed layer in which a part is concealed by a non-transparent part after irradiation with laser light.

[0188] 25(a) shows the state before irradiation with the laser light L, so the color or transparent layer 18 does not have the non-transparent portion 18K formed therein, and the pattern-printed layer 15 has stripes of color lines C, M, and Y.

[0189] On the other hand, when laser light L is irradiated and non-transparent portions 18K are formed above color lines M and Y in the pattern printing layer 15 as shown in Figure 24(b), the color lines M and Y are hidden by the non-transparent portions 18K, resulting in stripes of cyan from color line C and black from the non-transparent portions 18K as shown in Figure 25(b).

[0190] FIG. 26 is a partial perspective view showing, in particular, the pattern printed layer and the color-developing layer when the display is tilted and observed from a different direction.

[0191] Figure 26 is a perspective view of the display 10D shown in Figure 25(b) when tilted and observed from different directions. Figure 26(a) shows a perspective view of the display 10D when tilted with the front side facing up and observed in the y direction, and Figure 26(b) shows a perspective view of the display 10D when tilted with the front side facing up and observed in the x direction. Note that, between the non-transparent portions 18K, there are color-emitting or transparent layers 18 that have not been replaced by the non-transparent portions 18K, but for simplicity, the color-emitting or transparent layers 18 are not shown.

[0192] When the display 10D is tilted with the front side facing up and viewed in the y direction, as shown in Figure 26(a), a cyan color line C is observed between the black non-transparent portions 18K extending parallel to the y axis, which appears as dark cyan to the eyes of the viewer S.

[0193] On the other hand, when the display body 10D is rotated counterclockwise by 90 degrees, tilted with the front side facing upward, and observed in the x direction, as shown in FIG. 26(b), the cyan color line C is hidden by the black opaque portion 18K, so it appears black as a whole.

[0194] As described above, the display body 10D according to the present embodiment can exhibit a changing effect in which the appearance varies depending on the viewing direction. The principle of such a changing effect will be described below.

[0195] FIGS. 27 and 28 are partial cross-sectional views showing the display body according to the present embodiment, particularly the pattern printing layer and the color developing layer, for explaining the changing effect.

[0196] In order to realize a changing effect in which the appearance changes according to the viewing direction, the ratio of the thickness t of the opaque portion 18K to the gap g between the opaque portions 18 is important.

[0197] FIG. 27 shows an example where the thickness t is smaller than the gap g (t < g). In this case, as shown by the solid line arrow in the figure, even when observed obliquely, the color lines are not hidden and are visually recognized in the same way as when observed directly from above. In this case, the appearance hardly changes even when the viewing direction is changed.

[0198] In contrast, FIG. 28 shows an example where the thickness t is greater than or equal to the gap g (t ≧ g). In this case, as shown by the dotted line arrow in the figure, when observed obliquely, the color lines C, M, and Y are hidden by the opaque portion 18K. The degree of hiding varies depending on the thickness t, the gap g, and the viewing angle, and the appearance changes depending on the degree of hiding.

[0199] When the thickness t becomes sufficiently larger than the gap g (t >> g), even when viewed slightly obliquely, the color lines C, M, and Y are hidden by the opaque portion 18K, so that the color lines C, M, and Y cannot be seen at all and only the black of the opaque portion 18K can be seen.

[0200] Therefore, the ratio of the thickness t to the gap g is determined to an appropriate value that will provide a desired changing effect when the observation direction is changed.

[0201] FIG. 29 is a partial plan view of a pattern-printed layer that is not hidden by a non-transparent portion and a pattern-printed layer that is partially hidden by a non-transparent portion.

[0202] Fig. 29(a) shows the state before irradiation with laser light L, and Fig. 29(b) shows the state after irradiation with laser light L. Fig. 29(b) particularly shows the state in which non-transparent portions 18K have been formed above (on the front side in the figure) color lines C and Y. Because color lines C and Y are hidden by black non-transparent portions 18K, the unhidden color line M appears as stripes of magenta and black.

[0203] 30 and 31 are partial cross-sectional side views showing the relationship between thickness and gap corresponding to FIG. 29(b), particularly showing the pattern printed layer and color-developing layer of the display member.

[0204] FIG. 30 shows a case where the thickness t and the gap g are equal (t:g=1:1), and FIG. 31 shows a case where the gap g is twice the thickness t (t:g=1:2).

[0205] As shown in Figure 30, when t:g = 1:1, as shown by the arrow in the figure, when observed at an observation angle shallower than 45 degrees (0 to 45 degrees), the color line M is hidden by the non-transparent part 18K, so the overall image appears black to the observer S.

[0206] On the other hand, when t:g=1:2 as shown in Figure 31, as indicated by the dashed arrow in the figure, when observed at an observation angle shallower than 30 degrees (0 to 30 degrees), the color line M is hidden by the non-transparent portion 18K, so the image appears black overall. However, when the observation angle exceeds 30 degrees, magenta begins to appear, and as the observation angle increases, the proportion of magenta that is visible also increases. On the other hand, with the configuration shown in Figure 30, magenta is not visible unless the observation angle exceeds 45 degrees, so the changing effect is less likely to occur than with the configuration shown in Figure 31.

[0207] Generally, the color lines C, M, and Y are printed with a line width d of about 50 to 100 μm, but in the present invention, by using a special printing method such as the gravure offset printing described above, it is also possible to print with a line width d of about 20 μm. For example, if the color lines C, M, and Y are printed with a line width d of 50 μm and two of the colors are hidden so that only one color is displayed, by setting the thickness t of the color-developing or transparent layer 18 to about 50 μm, a changing effect can be obtained by rotating the display unit 10D in the xy plane while observing it from a 45-degree oblique observation angle.

[0208] In this way, the ratio of the gap g between the non-transparent portions 18K to the thickness t of the non-transparent portions 18K is not determined uniformly, but is determined appropriately taking into account various conditions such as the pattern and color to be expressed, the expected observation angle, and the line width that is technically printable.

[0209] In Figures 30 and 31, an example is described in which, in a pattern printing layer 15 consisting of a line pattern of three colors of color lines C, M, and Y, two colors of color lines C and Y are concealed and one color of color line M is not concealed, but it is also possible to conceal one color and not conceal two colors.

[0210] FIG. 32 is a partial plan view of a pattern-printed layer that is not concealed by a non-transparent portion and a pattern-printed layer that is partially concealed by a non-transparent portion.

[0211] Fig. 32(a) shows the state before irradiation with laser light L, and Fig. 32(b) shows the state after irradiation with laser light L. Fig. 32(b) particularly shows the state in which non-transparent portion 18K has been formed above (the front side in the figure) color line C. Since color line C is hidden by black non-transparent portion 18K, it results in a stripe of black, magenta of color line M that is not hidden by non-transparent portion 18K, and yellow of color line Y that is not hidden by non-transparent portion 18K.

[0212] As shown in FIGS. 32(a) and 32(b), by forming a non-transparent portion 18K by laser drawing in the coloring or transparent layer 18 above the color line C, only the cyan color can be concealed.

[0213] 33 and 34 are partial cross-sectional side views showing, in particular, the pattern print layer and color-developing layer of the display element, for explaining how it appears when a non-transparent portion is formed above the color line.

[0214] In Figure 33, the relationship between thickness t and gap g is t:g = 1:1, and in Figure 34, the relationship between thickness t and gap g is t:g = 1:2, but these are just examples and are not limiting.

[0215] 33, when t:g=1:1, as shown by the dashed arrow in the figure, when observed at an angle of 45 degrees or more, the red, which is a mixture of magenta and yellow, and the black of the non-transparent portion 18K appear as a dark red. Note that when observed at an angle shallower than 45 degrees, in addition to the color line C, which is originally hidden, the color lines M and Y are also hidden by the non-transparent portion 18K, and the overall image appears black.

[0216] By changing the ratio of thickness t to gap g, it is possible to adjust the appearance of colors, such as making magenta stronger or yellow stronger. Also, by changing the observation direction, the aforementioned changing effect can be obtained.

[0217] Figure 34 is a side cross-sectional view illustrating the difference in appearance when the observation direction is changed by 180 degrees. When viewed from the left side in Figure 34, color line Y is visible but color line M is hidden by non-transparent portion 18K, so it is observed as dark yellow, and when viewed from the opposite side, that is, the right side in the figure, color line M is visible but color line Y is hidden by non-transparent portion 18K, so it is observed as dark magenta.

[0218] FIG. 35 is a partial plan view showing a pattern-printed layer provided with two types of pattern-printed portions.

[0219] In Fig. 35, two types of pattern-printed portions p1 and p2 are provided on the pattern-printed layer 15A. Fig. 35(a) shows the state before laser drawing, and Fig. 35(b) shows the state after laser drawing.

[0220] 35(a) is a pattern printing section p1 consisting of a line pattern in which lines extend in the y direction, and the right half is a pattern printing section p2 consisting of a line pattern in which lines extend in the x direction. Both pattern printing sections p1 and p2 have a line pattern in which color lines C, M, and Y are repeatedly arranged in this order.

[0221] 35(b), in the pattern printing section p1, non-transparent portions 18K are formed above (on the front side in the figure) the color lines M and Y by drawing with the laser light L, and the magenta and yellow are concealed. As a result, stripes of cyan and black are formed from the unconcealed color lines C.

[0222] In addition, in the pattern printing section p2, non-transparent sections 18K are formed above (on the front side in the drawing) the color lines C and Y by drawing with the laser light L, and the cyan and yellow are concealed. As a result, magenta and black stripes are formed from the unconcealed color lines M.

[0223] FIG. 36 is a perspective view showing a state in which the display is tilted and observed along the y direction, and a state in which the display is rotated 90 degrees counterclockwise on the xy plane and observed along the x direction.

[0224] As shown in Figure 36(a), in the pattern printed portion p1, as in Figure 36(b), the stripes are cyan and black, but in the pattern printed portion p2, the color line M is hidden by the non-transparent portion 18K, and the entire portion is perceived as black due to the non-transparent portion 18K.

[0225] On the other hand, when the display 10D is rotated 90 degrees counterclockwise in the xy plane from the state shown in Figure 36(a), as shown in Figure 36(b), the pattern printed portion p2 has magenta and black stripes, similar to Figure 35(b), but in the pattern printed portion p1, the color line C is hidden by the non-transparent portion 18K, and the entire portion is perceived as black due to the non-transparent portion 18K.

[0226] FIG. 37 is a partial plan view of a display body, particularly a pattern-printed layer provided with two types of periodic pattern-printed portions.

[0227] In Fig. 37, two types of periodic pattern-printed portions are also provided on the pattern-printed layer 15. Both Fig. 37(a) and (b) show the state after laser drawing. The display element 10D shown in Fig. 37(b) shows the state in which the display element 10D shown in Fig. 37(a) is rotated 90 degrees counterclockwise in the xy plane.

[0228] In a display 10D shown in FIG. 37(a), the left half is a pattern printed portion p3 made up of lines extending in the y direction, and the right half is a pattern printed portion p4 made up of lines extending in the x direction.

[0229] In the pattern-printed section p3, a non-transparent section 18K is formed by laser drawing above (the front side in the drawing) the color line C. In addition, in the pattern-printed section p4, a non-transparent section 18K is formed by laser drawing above (the front side in the drawing) the color line M.

[0230] Therefore, as shown in FIG. 37(a), in the pattern printing portion p3, cyan is hidden, resulting in black, magenta, and yellow stripes, and in the pattern printing portion p4, magenta is hidden, resulting in cyan, black, and yellow stripes.

[0231] FIG. 38 is a diagram showing an example of the changing effect of the display body shown in FIG.

[0232] FIG. 38(a) shows the display 10D shown in FIG. 37(a) when tilted with the front side facing up and observed along the y direction.

[0233] As shown in Figure 38(a), the pattern printed portion p3 is observed in the same manner as in Figure 37(a), but in the pattern printed portion p4, the color line C is hidden by the non-transparent portion 18K, resulting in yellow and black stripes.

[0234] FIG. 38(b) shows the display 10D shown in FIG. 37(b) when tilted with the front side facing up and observed along the x direction.

[0235] As shown in Figure 38(b), the pattern printed portion p4 is observed in the same manner as in Figure 37(b), but in the pattern printed portion p3, the color line M is hidden by the non-transparent portion 18K, resulting in yellow and black stripes.

[0236] FIG. 38(c) shows the state observed when the display 10D is rotated 180 degrees in the xy plane from the state shown in FIG. 38(a) and tilted forward.

[0237] In the state shown in Figure 38(c), the pattern-printed portion p3 is observed in the same manner as in Figure 38(a), although the left and right are reversed. On the other hand, in the pattern-printed portion p4, the color line Y is hidden by the non-transparent portion 18K, resulting in cyan and black stripes.

[0238] Fig. 38(d) shows the state observed when display 10D is rotated 180 degrees in the xy plane from the state shown in Fig. 38(b) and tilted toward the user. Fig. 38(d) also shows the state observed when display 10D in the state shown in Fig. 38(c) is rotated 90 degrees counterclockwise in the xy plane and tilted toward the user.

[0239] In the state shown in Figure 38(d), the pattern-printed portion p4 is observed in the same manner as in Figure 38(b), although the left and right are reversed. On the other hand, in the pattern-printed portion p3, the color line Y is hidden by the non-transparent portion 18K, resulting in magenta and black stripes.

[0240] As described above, for example, as shown in FIG. 37, when only one color of a line pattern in which color lines C, M, and Y are repeated is concealed and two types of orthogonal repeating patterns are provided as pattern printing sections p3 and p4, a display 10D is tilted and observed while changing the observation direction by 90 degrees, and the image can be seen differently in all four directions, as shown in FIG. 38.

[0241] In the above explanation, a line pattern of three colors, C, M, and Y, or a line pattern of C, M, Y, and W, which is C, M, and Y plus a non-printed white portion W, is assumed to represent a color facial image, but this is not limited to this. Also, the colors of the repeating pattern may be not only the three colors, C, M, and Y, but also the three colors, RGB, and may further include the special color T described with reference to Figure 3. If lines of at least one color or more are repeated in two or more directions, the changing effect described above can be realized.

[0242] As described above, the display according to this embodiment can achieve a changing effect in which the image that is viewed changes when the viewing conditions, such as the viewing angle or viewing direction, change.

[0243] Until now, displays using laser drawing have been resistant to counterfeiting, but have had the drawback of being vulnerable to counterfeiting, as it is easy to imitate only the appearance. However, according to this embodiment, a display that is difficult to counterfeit or alter can be realized. Furthermore, the authenticity verification method of verifying the display by checking the changing effect does not require the use of special filters or devices, and can be easily performed on the spot by tilting or rotating the display.

[0244] In this embodiment, a rectangular display 10D has been described as an example, but as long as the display 10D is flat, its shape is not limited to a rectangular shape, and it may be polygonal or have a curved outline.

[0245] Example 2 Next, Example 2 will be described, in which a display 10D according to this embodiment was actually fabricated.

[0246] FIG. 39 is a diagram for explaining the changing effect of the display produced in this Example 2. In FIG.

[0247] In this Example 2, a display was created in which the image appears to change by tilting it forward and rotating it 90 degrees in the xy plane, as shown in Figures 39(a) and 39(b).

[0248] The display element 10D that realizes such a changing effect includes two pattern-printed portions p5 and p6, which are produced by printing separately.

[0249] FIG. 40 is a plan view showing an example of a printed matter 50 on which a first pattern printed portion p5 is printed.

[0250] FIG. 41 is a plan view showing an example of a printed matter 52 on which a second pattern printed portion p6 is printed.

[0251] FIG. 42 is a plan view showing an example of a printed matter 54 formed by overlapping a first pattern printed portion p5 and a second pattern printed portion p6.

[0252] In this example, to print a printed matter 50 with a first pattern printing section p5 as shown in the shaded area in Figure 40, a gravure offset printing machine was used to print a pattern printing layer 15 on a 100 μm thick sheet (SL2000) of color-forming layer 13. In this pattern printing layer 15, a line pattern consisting of three color lines C, M, and Y was printed so that the length direction of the line was 135° in the xy plane, forming a star shape. The line widths of the color lines C, M, and Y were C: 40 μm, M: 40 μm, and Y: 60 μm, and a 60 μm gap was provided between the color lines Y and C. This gap was used as a white line W.

[0253] In this example, to print a printed matter 52 with a second pattern-printed section p6, as shown in the shaded area of ​​FIG. 41, a gravure offset printing machine was similarly used to print a pattern-printed layer 15 on a 100 μm-thick sheet (SL2000) of color-developing layer 13. In this pattern-printed layer 15, a line pattern consisting of three color lines C, M, and Y was printed such that the length direction of the lines was at a 45-degree angle in the xy plane, and the star-shaped portion of the first pattern-printed section p5, as shown in FIG. 40, was printed in white. The line widths of the color lines C, M, and Y were 40 μm, 40 μm, and 60 μm, respectively, similar to those of the first pattern-printed section p5, and a 60 μm gap was provided between the color lines Y and C. This gap was used as a white line W.

[0254] The two printed materials 50, 52 with the line patterns printed in this way were sandwiched between a sheet of core layer 11 and a sheet of transparent layer 14, laminated, and fused by heat pressing to create a card. The heating conditions for fusion were a temperature of 190°C for 7 minutes, and the cooling conditions were 20°C for 5 minutes. The pressure during heating and cooling was adjusted appropriately depending on the elapsed time so as not to destroy the printed pattern.

[0255] The products used for each sheet are as follows: Transparent layer 14: "ST2000" manufactured by Mitsubishi Gas Chemical Company, Inc. (thickness: 50 μm) Pattern printing layer (printed matter 50, 52): Mitsubishi Gas Chemical Company, Inc. "SL2000" (thickness: 50 μm) Coloring layer 13 (pattern printed layer printed on top): "SL2000" manufactured by Mitsubishi Gas Chemical Company, Inc. (thickness: 50 μm) Core layer 11: "SW2000" (thickness: 200 μm) manufactured by Mitsubishi Gas Chemical Company, Inc.

[0256] FIG. 42 is a plan view showing a card as an example of a printed matter formed by overlapping a first pattern-printed portion and a second pattern-printed portion.

[0257] This card 60 includes a first pattern-printed section p5 and a second pattern-printed section p6. As shown in the inset of Figure 42, which shows an enlarged view of the boundary between the first pattern-printed section p5 and the second pattern-printed section p6, the length direction of the lines in the first pattern-printed section p5 and the length direction of the lines in the second pattern-printed section p6 are perpendicular to each other.

[0258] Such a card 60 was irradiated with laser light L from a laser drawing device 20 from above (the front side in the figure) to form non-transparent portions 18K in the color-producing layer 13, thereby realizing a full-color image.

[0259] The laser drawing device 20 can draw with an infrared laser having a spot diameter of 40 μm with a positional accuracy of 2 μm. The laser drawing device 20 can also adjust the power of the laser light L to generate black dots with a diameter of approximately 10 to 40 μm, forming the non-transparent portion 18K. By further providing a CCD camera in the laser drawing device 20, it is possible to detect the edges of the pattern-printed portions p5 and p6 and accurately perform laser drawing at predetermined positions on the printed color lines C, M, and Y. Using this laser drawing device 20, drawing was performed along the length of the lines, i.e., in the 135-degree xy coordinate direction for the first pattern-printed portion p5 and in the 45-degree xy coordinate direction for the second pattern-printed portion p6.

[0260] FIG. 43 is a diagram showing an example of a face image formed on a card by laser drawing.

[0261] Figure 43 shows an example in which a facial image a has been formed on a card 60 by laser drawing, where Figure 43(a) is a diagram similar to Figure 42 and shows the card 60 before drawing with laser light L, and Figure 43(b) shows a display 10D in which a facial image a has been formed in full color by drawing with laser light L on the card 60 shown in Figure 43(a).

[0262] When the display 10D illustrated in Fig. 43(b) is tilted and observed obliquely as shown in Fig. 39(a), the star-shaped portion of the facial image a that corresponds to the first pattern printed portion p5 is displayed in black. When the display 10D is further rotated 90 degrees clockwise on the xy plane from the state shown in Fig. 39(a) and observed, the image is inverted as shown in Fig. 39(b), and the facial image a is displayed in the star-shaped portion that was displayed in black in Fig. 39(a), and the portion where the facial image a was displayed in Fig. 39(a) is displayed in black.

[0263] In this way, it was confirmed that a changing effect can be obtained simply by rotating and observing the display 10D.

[0264] [Third embodiment] In the third embodiment of the present invention, variations on the printing method and laser drawing of the pattern printing layer in the display body according to the first and second embodiments will be described. Therefore, the contents already described in the first and second embodiments will be explained in a simplified manner as appropriate, avoiding duplication.

[0265] (Display body configuration) FIG. 44 is a side cross-sectional view showing an example of the configuration of a display according to the third embodiment before laser drawing.

[0266] FIG. 45 is a side cross-sectional view showing an example of the configuration of a display according to the third embodiment before and after laser drawing.

[0267] The display member 10E according to this embodiment is formed by laminating, from the bottom in FIG. 44, a substrate 16, a core layer 11, a color-forming layer 13, and an intermediate transfer unit 19. For example, PC can be used for the substrate 16. For example, PC can also be used for the core layer 11. For example, PC can also be used for the color-forming layer 13. The intermediate transfer unit 19 is provided with a pattern-printed layer 15 as described in the first and second embodiments. This pattern-printed layer 15 is provided on the intermediate transfer unit 19, which is formed by providing a fine color pattern print (first image) on an intermediate transfer film by a pigment indirect transfer method in which a pigment ink ribbon is printed by a thermal head, and then heat-fusing this intermediate transfer film to the color-forming layer 13. A transparent layer (not shown) may be further provided between the intermediate transfer film and the color-forming layer 13.

[0268] Thereafter, by irradiating the display body 10E with laser light L from a laser drawing device 20 (not shown in FIG. 44) from above in the figure, the inside of the color-forming layer 13 is colored black, forming non-transparent portions 18K, as shown in FIG. 45(b). The non-transparent portions 18K partially conceal the color lines C, M, and Y of the pattern-printed layer 15, allowing any color to be expressed. This allows for the color display of an image.

[0269] (Example of pattern printing) FIG. 46 is a plan view showing an example of a pattern used in the pattern printing layer.

[0270] The image can be formed using any line pattern such as that shown in FIG.

[0271] 46(a) shows a line pattern formed by regularly repeating color lines C, M, and Y. In the line pattern, it is desirable that the line width be approximately 20 μm to 50 μm in order to obtain sufficient image resolution.

[0272] Also, the color lines are not limited to CMY. For example, color filters used in liquid crystal displays often have patterns where the color lines C, M, Y are replaced with color lines R, G, B. In this embodiment as well, the color lines are not limited to C, M, Y and can also be R, G, B.

[0273] FIG. 46(b) is a halftone pattern in which, as color lines, in addition to C, M, Y, a blank area W which is a white area is further added, and C, M, Y, W are regularly repeatedly arranged. By adding the white color line W as well, the color gamut that can be expressed can be expanded.

[0274] FIG. 46(c) shows C, M, Y, W arranged in a "field" shape. According to such a configuration, since the colors can be arranged two-dimensionally, the resolution can be increased more than in the configuration where the colors are arranged as a one-dimensional halftone pattern as in FIGS. 46(a) and 46(b).

[0275] In this embodiment, the pattern printing as exemplified in FIG. 46 is individually printed for each display body 10E using a printer. Thereby, for example, when a passport is realized by the display body 10E, it can be printed individually for each passport owner, so that it is possible to provide a highly secure passport customized for each owner. In the following, such individual printing will be described.

[0276] (Printing method) In this embodiment, various printers can be used, but in particular, a pigment indirect transfer type printer is suitable. This printer prints a pigment ink ribbon onto an intermediate transfer film by a thermal head (primary transfer), and further thermally fuses the printed intermediate transfer film onto a substrate (secondary transfer). This method has the feature that fine thin lines with high contrast can be printed by using a pigment ribbon.

[0277] This printer can use a thermal head with a resolution of around 600 dpi, so it can stably print color lines with a line width of around 20 to 40 μm. This feature is extremely useful for high-precision printing.

[0278] Figure 47(a) is an enlarged photograph of fine printing made using the direct printing method on a substrate with unevenness, and Figure 47(b) is an enlarged photograph of fine printing (line width: 20 μm) made using the indirect transfer method on a sheet with minimal unevenness.

[0279] As is the case with inkjet printers, direct printing methods often result in lines that are distorted due to the unevenness of the substrate, as shown in Figure 47(a). This makes them unsuitable for printing fine, repeating patterns. Similarly, dye-ink ribbon printing results in blurred lines, making it unsuitable for pattern printing.

[0280] On the other hand, the indirect transfer method uses an intermediate transfer film, making it possible to print fine lines with higher precision, that is, with less distortion and higher linearity, as shown in FIG. 47(b).

[0281] Therefore, when the indirect transfer method is used, it is possible to incorporate security elements such as holograms into the intermediate transfer film, making it possible to provide high security in itself. Currently, holograms are used in many passports around the world. In the indirect transfer method, an image is printed on an intermediate transfer foil with a hologram, making it resistant to counterfeiting and alteration. Therefore, the indirect transfer method is a suitable printing method for printing passports with holograms.

[0282] The intermediate transfer film can be provided with a metal vapor deposition layer, such as aluminum. This metal vapor deposition layer can be removed with a laser, i.e., demetallized. Combining demetallization with fine color pattern printing can also create a new security element.

[0283] As described above, by using a printer that uses the indirect pigment transfer method, it is possible to individually print a fine color pattern for each owner of the display body 10E. This type of individual printing includes, for example, a fine color pattern having the outline of the owner's face photograph, or a fine color pattern of the owner's text information, such as the owner's name or ID.

[0284] By providing a fine color pattern with the outline of the owner's face photograph, it is possible to improve both security and image quality. For example, in conventional technology, a color pattern is provided over the entire face photograph printing area, making it easy to add hair, beard, etc. to stolen goods by drawing it with a laser beam. However, with the display 10E according to this embodiment, a color pattern can be provided only in the face photograph area, making it difficult to counterfeit.

[0285] Furthermore, in the prior art, the background of the facial photograph was a color pattern, which resulted in a dark overall background and poor contrast with the facial photograph. However, the display 10E according to this embodiment eliminates the color pattern background and displays only the facial photograph, thereby improving contrast.

[0286] Furthermore, in conventional technologies, colors are displayed by hiding a uniform color pattern, which narrows the color gamut that can represent a facial photograph. However, with the display 10E according to this embodiment, the density and color balance of the color pattern itself can be adjusted as desired, which improves the reproducibility of facial photographs.

[0287] Furthermore, in the prior art, both the color-forming layer that darkens under laser light and the line color pattern are provided inside the substrate, making them difficult to tamper with. In contrast, in the display 10E according to this embodiment, the pattern-printed layer 15 is provided on the outermost surface side. However, because the color-forming portion 213 is located inside the substrate 16, it is difficult to tamper with, and high security can be achieved without providing the pattern-printed layer 15 inside the substrate.

[0288] Furthermore, according to this embodiment, when the display element 10E is applied to a passport, character strings containing personal information, such as the owner's name or ID number, can be printed using a color pattern. In this case, laser marking can be used to conceal some of the color, allowing the character strings to be displayed in any color. Furthermore, by providing a transparent layer between the intermediate transfer film and the color-developing layer 13 or by adjusting the color-developing layer 13 to an appropriate thickness, a changing effect can be achieved, allowing the color of the character string to change depending on the viewing angle. Similarly to a face photograph, pattern printing only the character string improves visibility because the rest of the passport is a white background. In this case, printing the background also reduces contrast, but it is possible to achieve separate color changes for the background and character. Furthermore, similar to a face photograph, even if the outermost intermediate transfer layer 19 and pattern-printed layer 15 are scraped off, it is difficult to scrape off the color-developing layer 13 located inside the substrate 16, thereby preventing falsification.

[0289] Unlike conventional techniques, the display 10E according to this embodiment expresses colors by concealing minute color patterns. Although this method is inferior to conventional techniques in terms of color reproducibility, it is possible to clearly determine that the product is genuine by simply checking with a magnifying glass or the like, and counterfeiting is extremely difficult.

[0290] (Changing effect) FIG. 48 is a partial cross-sectional side view showing an example of the configuration of a display member 10E in which a transparent layer 12 is provided between a pattern-printed layer 15 and a color-producing layer 13. In FIG.

[0291] FIG. 49 is a plan view showing the pattern-printed layer 15 observed when the display 10E shown in FIG. 48 is viewed from directly above.

[0292] FIG. 49(a) shows the state before laser drawing, and FIG. 49(b) shows the state after laser drawing.

[0293] In the display member 10E according to this embodiment, as shown in Fig. 48, a transparent layer 12 is provided between the pattern-printed layer 15 and the color-forming layer 13. By providing the transparent layer 12 between the pattern-printed layer 15 and the color-forming layer 13 in this way, it is possible to achieve a more pronounced changing effect, as will be described below.

[0294] As shown in FIG. 49(a), the pattern printed layer 15 is provided with a line pattern in which color lines C, M, and Y are regularly and repeatedly arranged. As shown in FIGS. 48(a) and 48(b), the portion of the coloring layer 13 below the color line C is blackened by irradiation with laser light, forming a non-transparent portion 18K.

[0295] When the pattern-printed layer 15 having the non-transparent portion 18K formed below the color line C is viewed from directly above, light is not reflected below the color line C, and the color line C is hidden and appears black. Therefore, as shown in Figure 49(b), the result is black, yellow, and magenta stripes.

[0296] 48(b) is a partial cross-sectional side view of the display body 10E, particularly for explaining how the display body 10E looks when viewed obliquely. In this example, the thickness h of the transparent layer 12 and the width d of the color lines C, M, and Y are equal (h=d).

[0297] In Figure 48(b), as indicated by the arrow from the left, when observed from a 45-degree diagonal angle to the left, magenta is not visible because color line M is hidden by the non-transparent portion 18K formed below color line C. On the other hand, as indicated by the arrow from the right, when observed from a 45-degree diagonal angle to the right, yellow is not visible because color line Y is hidden by the non-transparent portion 18K formed below color line C. In this way, the visible color changes when observed from directly above and when observed from an oblique angle, thereby achieving a changing effect. Furthermore, even when observed from a 45-degree diagonal angle, the color changes when viewed from the right and left, achieving a changing effect.

[0298] The above describes the changing effect of display body 10E that has a transparent layer 12 between pattern printing layer 15 and color-forming layer 13, but even if display body 10E does not have a transparent layer 12, it can achieve the changing effect as long as color-forming layer 13 has an appropriate thickness.

[0299] FIG. 50 is a partial cross-sectional side view showing an example of the configuration of a display member 10E in which there is no transparent layer between the pattern-printed layer 15 and the color-producing layer 13. In FIG.

[0300] In the example shown in FIG. 50, the thickness t of the coloring layer 13 and the width d of the color lines C, M, and Y are equal (t=d).

[0301] As shown in FIG. 50, in the coloring layer 13, the portion below the color line C is blackened by irradiation with the laser light, and a non-transparent portion 18K is formed.

[0302] In this case, as shown by the arrow in Figure 50(a), when the pattern-printed layer 15 is observed from directly above, the area below the color line C is blackened by the non-transparent portion 18K, so light is not reflected by the color line C. Therefore, as shown in Figure 49(b), the color line C is hidden, and appears as black, yellow, and magenta stripes.

[0303] On the other hand, as shown by the arrow in Figure 50(b), when the pattern printing layer 15 is observed from an oblique direction, the ratio of the line width d of the color line to the thickness t of the color-producing layer 13 is 1:1, so when observed from a 45-degree diagonal angle to the left, the cyan and magenta are hidden, resulting in stripes of yellow and black, and when observed from a 45-degree diagonal angle to the right, the cyan and yellow are hidden, resulting in stripes of magenta and black.

[0304] In this way, the display element 10E according to this embodiment can achieve a changing effect by changing the visible color when observed from directly above and when observed from an oblique direction, even though it does not have a transparent layer 12 between the pattern-printed layer 15 and the color-producing layer 13. Even when observed from a 45-degree oblique direction, the color changes when viewed from the right side and when viewed from the left side, achieving a changing effect.

[0305] Next, the relationship between the line width d of the color line in the pattern-printed layer 15, the thickness t of the color-developing layer 13, and the observation direction will be described.

[0306] Figure 51 is a partial side cross-sectional view showing the display element 10E, particularly the pattern printed layer 15 and the color forming layer 13, to explain the relationship between the line width d of the color line in the pattern printed layer 15, the thickness t of the color forming layer 13, and the observation direction.

[0307] 51(a), (b), and (c), the color-producing layer 13 below the color lines C and Y is drawn by irradiating it with laser light, forming non-transparent portions 18K. Therefore, when observed from directly above, they appear as magenta and black stripes.

[0308] However, as shown in FIGS. 51(b) and (c), when observed from an oblique direction, the appearance differs depending on the ratio of the line width d of the color line to the thickness t of the color-producing layer 13 and the observation angle.

[0309] 51(b) shows an example in which the ratio of line width d to thickness t is 1:1. In this case, when viewed from an oblique direction in the figure, at an angle of 45 degrees or more with respect to the plane (xy plane) including the top surface of display unit 10E, color line M is not hidden, and magenta can be observed. However, when viewed at an angle shallower than 45 degrees (0 to 45 degrees), color line M is hidden, and magenta cannot be observed, resulting in a changing effect in which the display appears black overall.

[0310] 51(c) shows an example in which the ratio of line width d to thickness t is 2:1. In this case, when viewed from an oblique direction in the figure, at an angle of 30 degrees or more with respect to the plane (xy plane) including the top surface of display unit 10E, color line M is not hidden, and magenta can be observed. However, when viewed at an angle shallower than 30 degrees (0 to 30 degrees), color line M is hidden, making it impossible to observe magenta, resulting in a changing effect in which the display appears black overall.

[0311] In this way, when the ratio between the line width d of the color line and the thickness t of the color-producing layer 13 is different, the observation angle at which the changing effect is obtained also differs.

[0312] In this embodiment, the line width d of the color lines C, M, and Y is approximately 20 to 50 μm. For example, when color lines C, M, and Y with a line width d of 40 μm are printed and a non-transparent portion 18K is provided below the color lines C and Y as illustrated in Fig. 51, by setting the thickness t of the color-producing layer 13 to approximately 40 μm, a changing effect is obtained in which magenta is visible when the display body 10E is observed from an angle greater than 45 degrees, but the magenta is no longer visible when the display body 10E is observed from an angle less than 45 degrees, and the overall image appears black.

[0313] It should be noted that the above explanation is merely an example, and the ratio between the line width d and the color-producing layer thickness t cannot be uniformly determined, but can be determined appropriately depending on various conditions such as the pattern and color to be expressed, the expected observation angle, and the line width that is technically printable.

[0314] (Example of color pattern) In this embodiment, a color pattern (fine repeating pattern) such as the pattern printing layer 15 is formed by a printer. The printer can easily print multiple types of patterns on one display 10E. Repeating patterns include one-dimensional patterns such as lines as described above, and two-dimensional patterns as shown in FIG. 46(c). Here, an example of a one-dimensional color pattern of lines will be introduced.

[0315] FIG. 52 is a plan view showing an example of a pattern printing layer consisting of a line-type one-dimensional pattern of various colors.

[0316] Elements that define a line-type color pattern include the number of types of color lines, the order of the color lines, the length direction of the lines, the line width of each color line, and the gap between each color line (if white lines are included).

[0317] Figure 52(a) shows a line-type color pattern in which color lines C, M, and Y are repeatedly arranged in this order, with the length direction of the lines coinciding with the y direction in the figure and perpendicular to the x direction, while the repeating direction of the lines coincides with the x direction in the figure and perpendicular to the y direction.

[0318] Figures 52(b) and (c) are also line-type color patterns in which color lines C, M, and Y are repeatedly arranged in this order, similar to Figure 52(a), but the color pattern shown in Figure 52(b) is the color pattern shown in Figure 52(a) rotated 45 degrees counterclockwise, and the color pattern shown in Figure 52(c) is the color pattern shown in Figure 52(a) rotated 90 degrees counterclockwise.

[0319] FIG. 52(d) is a color pattern obtained by rotating the line pattern of FIG. 52(c) by 180 degrees on the xy plane.

[0320] Figure 52(e) is similar to Figures 52(c) and (d) in that the length direction of the lines coincides with the x direction, but the arrangement pattern of the color lines is different from Figures 52(c) and (d), and the color lines are repeated in a YMCCMY arrangement pattern.

[0321] Figure 52(f) is similar to Figure 52(a) in that the length direction of the lines coincides with the y direction, but it is a line-type color pattern in which color line Y is not used and only color lines C and M are arranged alternately and repeatedly.

[0322] FIG. 52(g) is a line-type color pattern in which the color lines C, M, and Y in the color pattern of FIG. 52(a) are replaced with color lines R, G, and B.

[0323] Figure 52(h) is the same as the color pattern in Figure 52(a), but is shown to facilitate comparison with the color patterns shown in Figures 52(i) and (j) described below. In Figure 52(h), the line width of the color lines C, M, and Y is 40 μm, and the same color lines are arranged at a pitch of 120 μm.

[0324] Figure 52(i) shows a color pattern in which the line width of each color line in the color pattern shown in Figure 52(h) is halved to 20 μm, and the remaining 20 μm is replaced with white color lines W. Therefore, even in this color pattern, the same color lines (except for the white lines W) are arranged at a pitch of 120 μm.

[0325] Figure 52(j) is a line-type color pattern that is half the color pattern shown in Figure 52(h). That is, the line width of the color lines C, M, and Y is 20 μm, the pitch is 60 μm, and there is no white color line W.

[0326] (Color changing effect depending on the order) In a line-type color pattern consisting of color lines C, M, and Y, the line width d, transparent layer thickness h, and line direction are all kept the same, but simply the order of the colors is changed, for example, from CMY to YMC, to achieve a changing effect. This will be explained using Figures 53A and 53B.

[0327] FIG. 53A is a diagram illustrating a display 10E designed to display the letter "A."

[0328] FIG. 53B is a diagram illustrating a display 10E designed to display the letter "B."

[0329] Figure 53A(a) is a plan view showing the line pattern of the pattern printing layer 15 designed to display the letter "A", in which the color lines C, M, and Y are arranged regularly and repeatedly in this order to form a line pattern.

[0330] On the other hand, Figure 53B(a) is a plan view showing the line pattern of the pattern printing layer 15 designed to display the letter "B", in which the color lines Y, M, and C are arranged regularly and repeatedly in this order.

[0331] Fig. 53A(c) is a partial elevational cross-sectional view of the display body 10E, showing a state in which a laser beam has been applied to form a non-transparent portion 18K in the color-producing layer 13 below the color line Y. The plan view of the display body 10E, in which a non-transparent portion 18K has been formed below the color line Y in this way, corresponding to Fig. 53A(a), is a striped pattern of repeated cyan, magenta, and black, as shown in Fig. 53A(b).

[0332] In this case, when the display 10E is viewed from directly above, the letter "A" is displayed in blue, which is a mixture of cyan and magenta, as shown in FIG. 53A(d).

[0333] Next, the display 10E is observed from a 45-degree diagonal direction. As shown in Fig. 53A(c), when observed from a 45-degree diagonal direction to the left, the color line M is closer to the viewer than the color line Y (to the left in the figure), and is therefore hidden by the non-transparent portion 18K. As a result, as shown in Fig. 53A(e), only the color line C is displayed, and the letter "A" is displayed in cyan. On the other hand, when observed from a 45-degree diagonal direction to the right, as shown in Fig. 53A(c), the color line C is closer to the viewer than the color line Y (to the right in the figure), and is therefore hidden by the non-transparent portion 18K. As a result, as shown in Fig. 53A(f), only the color line M is displayed, and the letter "A" is displayed in magenta.

[0334] On the other hand, Figure 53B(c) is a partial elevational cross-sectional view of the display body 10E, showing a state in which a laser beam has been applied to form a non-transparent portion 18K in the color-producing layer 13 below the color line Y. The plan view of the display body 10E in which a non-transparent portion 18K has been formed below the color line Y in this way, corresponding to Figure 53B(a), is a striped pattern of repeated cyan, magenta, and black, as shown in Figure 53B(b).

[0335] In this case, when the display 10E is viewed from directly above, the letter "B" is displayed in blue, which is a mixture of cyan and magenta, as shown in FIG. 53B(d).

[0336] Next, the display 10E is observed from a 45-degree angle. As shown in FIG. 53B(c), when observed from a 45-degree angle to the left, the color line C is closer to the viewer than the color line Y (to the left in the figure), and is therefore hidden by the non-transparent portion 18K. As a result, as shown in FIG. 53B(e), only the color line M is displayed, and the letter "B" is displayed in magenta. On the other hand, when observed from a 45-degree angle to the right, as shown in FIG. 53B(c), the color line M is closer to the viewer than the color line Y (to the right in the figure), and is therefore hidden by the non-transparent portion 18K. As a result, as shown in FIG. 53B(f), only the color line C is displayed, and the letter "B" is displayed in cyan.

[0337] In this way, in the display 10E according to this embodiment, the same character changes color when viewed from different angles. Therefore, authenticity can be easily determined by confirming that the color changes as designed.

[0338] In the above example, an example in which the color of text is changed has been described, but below, an example in which the color of a graphic is changed will be described.

[0339] FIG. 54A is a perspective view of a display 10E showing an example in which the color of the star-shaped pattern and the color of its background change when viewed from different viewing angles.

[0340] FIG. 54B is a plan view showing how the display 10E shown in FIG. 54A appears when viewed from directly above.

[0341] The changing shown in FIG. 54A can be understood by replacing the letter "A" described in FIG. 53A with a star-shaped figure, and the letter "B" described in FIG. 54B with a background.

[0342] Therefore, the star-shaped figure is created by forming a non-transparent portion 18K in the color-producing layer 13 below the color line Y, as shown in FIG. 53A(c), in the pattern-printed layer 15 shown in FIG. 53A(a).

[0343] The background is created by forming a non-transparent portion 18K in the color-producing layer 13 below the color line Y as shown in FIG. 53B(c) in the pattern-printed layer 15 shown in FIG. 53B(a).

[0344] Therefore, when such a display 10E is observed from directly above, the entire surface appears blue, which is a mixture of the cyan of color line C and the magenta of color line M, as shown in FIG. 54B.

[0345] When display device 10E as shown in Fig. 54B is viewed from diagonally above with the front side facing up, the star-shaped portion appears magenta and the background portion appears cyan, as shown in Fig. 54A(a). On the other hand, when display device 10E is rotated 180 degrees counterclockwise in the xy plane and viewed from the same direction, the colors are reversed, and the star-shaped portion appears cyan and the background portion appears magenta, as shown in Fig. 54A(b).

[0346] In this way, by tilting the display 400, the latent image, which is a star-shaped figure, can be made visible, and further, by viewing the display 400 rotated 180 degrees counterclockwise in the xy plane, a color-changing effect can be achieved in which the colors are reversed.

[0347] As explained in the second embodiment with reference to FIG. 38, it is also possible to achieve a changing effect in which the image appears different in all four directions.

[0348] The changing effect described above is not limited to line patterns consisting of three color lines such as CMY or RGB, but can also be achieved using line patterns consisting of two color lines. It can also be achieved using a line pattern consisting of four colors by adding a white area W with no printing in addition to the three colors. As long as at least one color of line is a repeating pattern in two or more directions, the changing effect can be achieved even when special colors are used.

[0349] (Effects of the Invention) As described above, the display according to this embodiment can achieve a changing effect, where the appearance changes when tilted or rotated. Such a display can be deterred from being counterfeited or altered, and is therefore suitable for use as a personal authentication medium such as a passport.

[0350] The anti-counterfeiting performance differs depending on the configuration and the security elements incorporated, but the following specific effects can be obtained depending on the elements incorporated.

[0351] For example, a case will be described in which the display according to this embodiment is applied to a passport, and the outline of the face photograph of the passport owner is formed with a fine color pattern.

[0352] The authenticity of such a passport can be easily determined by observing the drawn image under magnification using a magnifying glass or the like.

[0353] Furthermore, by drawing on such passports using laser light, it is possible to prevent falsification such as adding hair or the like later.

[0354] You can also leave the background of your passport photo white, which will improve the contrast.

[0355] Furthermore, when the passport is tilted or rotated, the color of the photograph changes due to a changing effect, making it possible to determine its authenticity at a glance.

[0356] Next, we will explain the effects that can be achieved when the owner's text information, such as the name or ID, is formed in a fine color pattern on a passport. In this case, it is possible to express a color string of characters while also achieving the effect of preventing forgery through laser processing. In addition, by tilting or rotating the passport, the color of the characters can be changed through a changing effect, making it possible to determine authenticity at a glance. Furthermore, by using multiple color patterns for the text information, the color of the characters can be changed in a complex manner.

[0357] Conventionally, personal authentication media using laser drawing have had the drawback of being vulnerable to counterfeiting, even if they are resistant to alteration, as it is easy to imitate only the appearance. However, with the display of this embodiment, authenticity can be easily determined using common methods such as "tilting" and "rotating" without using any special filters or devices, and counterfeiting and alteration can be made difficult.

[0358] Example 3 Next, a third example will be described in which an ID card is produced using a display according to this embodiment.

[0359] (Card Creation) First, a sheet for the color-forming layer 13 made of PC and a sheet for the core layer 11 were laminated and fused by heat pressing. The heating conditions for fusion were 190°C for 7 minutes, and the cooling conditions were 20°C for 5 minutes. The pressure during heating and cooling was adjusted appropriately depending on the elapsed time. The sheet obtained in this manner was punched into a card shape to produce cards.

[0360] The following products were used for each sheet: Coloring layer 13: Mitsubishi Gas Chemical: SL2000: 100 μm Core layer 11: Mitsubishi Gas Chemical: SW2000: 200 μm.

[0361] (Printing images) Next, a line pattern was printed on the card using a pigment indirect transfer printer (CP500, manufactured by TOPPAN Holdings Co., Ltd.) by repeatedly arranging color line groups consisting of three color lines C, M, and Y on the card, while leaving a non-printing area, a white color line W, between the next color line groups. The line width of each of these color lines C, M, Y, and W was 40 μm.

[0362] FIG. 55 is a plan view showing an example of a created card on which an image has been printed.

[0363] In this embodiment, as shown in FIG. 55, three types of pattern printing portions p1, p2, and p3 are printed on the card 60, which are distinguished by the arrangement order of the color lines and the inclination of the lines in the length direction.

[0364] The pattern printed portion p1 is printed to form the outline of the face of the owner of the card 60, the pattern printed portion p2 is printed to form the letter "A", and the pattern printed portion p3 is printed to form the letter "B".

[0365] As shown in the partially enlarged view inserted in Figure 55, the pattern printing section p1 has color lines repeatedly arranged in the order of Y, M, C, and W from the top of the figure, and the longitudinal direction of the lines is slightly tilted upward and to the right with respect to the y-axis.

[0366] As shown in the enlarged partial view inserted in Figure 55, the pattern printing section p2 also has color lines repeatedly arranged in the order of Y, M, C, and W from the top of the figure, but the length direction of the lines is parallel to the y axis.

[0367] As shown in the partially enlarged view inserted in Figure 55, the pattern printing section p3 has color lines repeatedly arranged in the order of C, M, Y, and W from the top of the figure, and the length direction of the lines is parallel to the y axis.

[0368] (Drawing non-transparent parts) As shown in FIG. 55, a non-transparent portion 18K was formed in the color-developing layer 13 by performing laser drawing on a card 60 on which an image was printed.

[0369] FIG. 56 is a plan view showing an example of a card 60 on which, in addition to the image shown in FIG. 55, a non-transparent portion 18K is formed.

[0370] Laser marking was performed using a dedicated device that employs a laser marker (manufactured by Keyence Corporation). This dedicated device can mark with an infrared laser with a spot diameter of 40 μm with a positional accuracy of 2 μm, and by adjusting the laser power, black dots with a diameter of approximately 10 to 40 μm were generated to form the non-transparent 18K area. In addition, by equipping this dedicated device with a CCD camera, the edges of the pattern printing area can be detected and the markings can be accurately placed at the designated positions on the printed color lines C, M, and Y.

[0371] The pattern printed portion p1 forming the facial contour was aligned so that part of the color lines C, M, and Y were hidden by the non-transparent portion 18K, and laser light was irradiated to create a color face image a.

[0372] FIG. 57 is a partial plan view of a display 10E for explaining an example in which a predetermined color is concealed in the pattern-printed portion p1 by laser drawing.

[0373] FIG. 57(a) is a partial plan view illustrating the pattern printed portion p1 before laser drawing.

[0374] Figure 57(b) is a plan view illustrating a color pattern in the pattern printing section p1 in which the entire color lines C and Y are hidden by a non-transparent section 18K, which is a collection of black dots K formed in the color-producing layer 13 by laser drawing, and magenta is displayed.

[0375] Figure 57(c) is a plan view illustrating a color pattern in the pattern printing section p1 in which the entire color lines M and Y are hidden by a non-transparent section 18K, which is a collection of black dots K formed in the color-producing layer 13 by laser drawing, and cyan is displayed.

[0376] Figure 57(d) is a plan view illustrating a color pattern in the pattern printing section p1 in which the entire color line M and part of the color line Y are concealed by a non-transparent section 18K, which is a collection of black dots K formed in the color layer 13 by laser drawing, and cyan and a slight yellow are displayed.

[0377] This laser pattern was drawn in accordance with the line pattern of facial image a, concealing the specified color of the lines. In this way, facial image a is expressed in color. Furthermore, the background part of facial image a is left as the white of the base material. This has resulted in facial image a with better visibility than conventional technology.

[0378] Laser drawing was performed on pattern printing area p2 forming the letter "A" and pattern printing area p3 forming the letter "B" so as to conceal only the color line C. With conventional technology, it was difficult to express a string of characters in color, but it was confirmed that the personal authentication medium realized by card 60 obtained in this way could express the string of initials "A" and "B" in color.

[0379] Furthermore, a character string such as the owner's personal information is drawn in a character string drawing area 61 on the left half of the card 60, completing a personal authentication medium 62.

[0380] (Authenticity determination) Next, a method for determining the authenticity of the personal authentication medium 62 will be described.

[0381] FIG. 58 is a plan view and a perspective view showing how the personal authentication medium appears.

[0382] FIG. 59 is a perspective view showing how the appearance of the personal authentication medium changes due to the changing effect.

[0383] Figure 58(a) shows the personal authentication medium 62 as viewed from directly above, where facial image a is displayed in full color and the string of characters "A·B" below it are both displayed in cyan, as shown in an enlarged view in Figure 58(b).

[0384] FIG. 58(c) is a perspective view showing the personal authentication medium 62 tilted with the front side facing up and observed from the front side.

[0385] In the state shown in Figure 58(c), the facial image a has changed from the state shown in Figure 58(a) to gray, and only the character "B" below it has changed from cyan to gray, as shown in an enlarged view in Figure 58(d). "A" remains cyan.

[0386] Figures 59(a) and (b) are the same as Figures 58(c) and (d).

[0387] Figure 59(c) is a perspective view showing the personal authentication medium 62 shown in Figure 59(a) rotated 180 degrees on the xy plane. Figure 59(d) is a diagram showing how the character string appears on the personal authentication medium 62 shown in Figure 59(c).

[0388] When the personal authentication medium 62 shown in Figure 59(a) is rotated 180 degrees counterclockwise on the xy plane, the color of the facial image a does not change and remains displayed in gray, as shown in Figures 59(c) and (d), but a changing effect occurs in which the color of the string of characters ``A'' changes from cyan to gray and ``B'' changes from gray to cyan.

[0389] As described above, when the personal authentication medium 62 created using the display 10E according to this embodiment is tilted, the color of the facial image and part of the character string appears to change, and when it is rotated in the xy plane, the color of part of the character string changes, and it has been confirmed that this changing effect is effectively exerted. Due to this changing effect, the display 10E according to this embodiment can easily and reliably determine authenticity.

[0390] Although the best mode for carrying out the present invention has been described above with reference to the accompanying drawings, the present invention is not limited to such a configuration. Those skilled in the art may conceive of various modifications and alterations within the scope of the technical ideas of the invention as defined in the claims, and it is understood that such modifications and alterations also fall within the technical scope of the present invention. [Explanation of symbols]

[0391] 10 Display (first embodiment) 10A Display body (modification of the first embodiment) 10B Display (modification of the first embodiment) 10C Display body (modification of the first embodiment) 10D Display (Second Embodiment) 10E Display (Third embodiment) 11 Core layer 12 Transparent layer 13 Coloring layer 14 Transparent layer 15 Pattern printing layer 16 Base material 17 Colored or transparent layer 18 Colored or transparent layer 18K non-transparent part 19 Intermediate transfer unit 20 Laser drawing device 30 Validator 31 Transparent area 32 Hidden Area 35 Validator 36 Light blocking section 37 Windows 40 portions 42 parts 50 printed matter 52 Printed matter 60 cards 61 String drawing area 62 Personal authentication media B Black color line C Cyan color line D Star mark (latent image) E numbers (latent image) G Green color line H View direction K black dot L laser light M Magenta color line P period R Red color line S Observer T(1~3) Special color line W White color line Y Yellow color line a Facial image d Color line width g. Gap between non-transparent parts h transparent layer thickness p1 Pattern printing section p2 Pattern printing section p3 Pattern printing section p4 Pattern printing section p5 First pattern printing section p6 Second pattern printing section t Thickness of the opaque part xx axis yy axis zz axis

Claims

1. A display that displays an image in color, a group of color lines, each of which is made up of a plurality of colors that realize a color display of the image, and which are periodically arranged so as to form a line; a plurality of concealing portions that conceal some of the color lines in the group of color lines; The outer diameter of each of the concealing portions is smaller than the line width of the color line.

2. The display according to claim 1, wherein the concealing portions are arranged in one or more rows, continuously or discretely along the length of the arbitrary color line, so as to conceal at least a portion of the arbitrary color line.

3. The display according to claim 2 , wherein the concealing portions are arranged at any density along the length direction in each column.

4. The laser light further includes a coloring layer in which the portion irradiated with the laser light turns black to form black dots, The display according to claim 2 , wherein the concealing portion is a black dot formed in the color-producing layer.

5. The display of claim 1 , wherein the plurality of colors includes cyan, magenta, and yellow.

6. The display according to claim 1 , wherein the plurality of colors includes a plurality of spot colors.

7. The display according to claim 4 or 5, wherein the plurality of colors further includes white.

8. The display according to claim 1 , wherein the color lines have the same line width.

9. The display according to claim 1 , wherein a line width of any one of the color lines is different from a line width of the other color lines.

10. 2. The display according to claim 1, wherein each of the color lines forming the parallel lines has a rectangular shape.

11. The display according to claim 10 , wherein the strips are rectangular in shape.

12. The display according to claim 10 , wherein at least a portion of the strip has a wavy line shape.

13. The display according to claim 10 , wherein at least a portion of the strip has a shape of a broken line.

14. When the black dots are arranged in multiple rows for multiple color lines of the same color, For the color line closest to a first direction among the plurality of color lines of the same color, the black dots are arranged with the highest density in the column closest to the first direction among the plurality of columns, For the color line closest to the second direction among the plurality of color lines of the same color, the black dots are arranged with the highest density in the column closest to the second direction among the plurality of columns, The display according to claim 4 , wherein the first direction is perpendicular to the length direction, and the second direction is opposite to the first direction.

15. A substrate; a print layer including the color lines; the color-developing layer, the printing layer is between the substrate and the color-forming layer; or The display according to claim 4 , wherein the color-forming layer is located between the substrate and the print layer.

16. A method for verifying authenticity of the display according to claim 4 using a verification device, comprising: the verifier, when overlaid on the display body, has concealing regions extending in the length direction that conceal the row of black dots and transparent regions extending in the length direction that transmit the row of black dots, which are alternately arranged in a direction perpendicular to the length direction so as to form a line pattern; The number of rows of black dots transmitted by each transparent region is at most one row on each color line of the designated color; An authenticity verification method in which, when the verifier is superimposed on the display so that each transparent area corresponds to one row of each color line of the specified color, the display is verified by a first image visualized by one row of black dots observed through each transparent area.

17. 17. The method for verifying authenticity according to claim 16, wherein the display medium according to claim 14 is verified using the verification device, An authenticity verification method for verifying the display using the first image and a second image that is visualized by a row of black dots observed through the transparent area when the display on which the verifier is superimposed is tilted from the state in which the first image is visualized.

18. A method for verifying the display according to claim 4 using a verification device, comprising: the black dots belong to either a first group of black dots arranged at a first period along the length direction in each of a plurality of rows corresponding to a designated color line, or a second group of black dots arranged at the first period so as to be shifted by half a period from the first group of black dots; the verifier has a plurality of windows arranged at the first period along the length direction to pass the color of the specified color line; When the verifier is moved in the length direction while being superimposed on the display body so that the plurality of windows are positioned on the row of the specified color lines, It is displayed alternately every half cycle. a first display pattern realized by the color of the specified color line not passing through windows blocked by black dots belonging to the first group of black dots among the plurality of windows, and the color of the specified color line passing through other windows; The authenticity verification method verifies the display body by a second display pattern realized by the color of the specified color line not passing through windows blocked by black dots belonging to the second group of black dots among the plurality of windows, and the color of the specified color line passing through the other windows.

19. A method for producing a display device that displays an image in color, the display device including a printing layer and a coloring layer that, when irradiated with laser light, turns black in the irradiated portion to form black dots, the method comprising: a step of printing, on the printing layer by gravure offset printing, a group of color lines, each of which is made up of a plurality of colors used for the color display and which are periodically arranged so as to form a line; and irradiating the color-producing layer with laser light to form black dots that conceal part of the color lines.

20. A substrate; a group of color lines, each of which is made up of a plurality of colors for displaying an image in color and is periodically arranged on the base material so as to form a line array; a transparent layer disposed on the base material so as to cover the group of color lines; a portion of the transparent layer is replaced with a non-transparent portion that conceals a portion of the color lines of the group of color lines; A display body, wherein the thickness of the non-transparent portion is equal to or greater than the line width of each of the color lines.

21. A substrate; a plurality of color line groups, each of which is made up of a plurality of colors for displaying an image in color and is periodically arranged on the base material so as to form a line array; a transparent layer disposed on the base material so as to cover the plurality of color line groups; a first length direction of a color line of at least one of the plurality of color line groups is different from a second length direction of a color line of the other color line groups; a portion of the transparent layer is replaced with a non-transparent portion that conceals a portion of the color lines of each group of color lines; A display body, wherein the thickness of the non-transparent portion is equal to or greater than the line width of each of the color lines.

22. The display of claim 21 , wherein the first length direction and the second length direction are orthogonal to each other.

23. The display body has a polygonal shape in a two-dimensional plane perpendicular to the layer direction, The display according to claim 22 , wherein the first length direction is parallel to one side of the polygon.

24. The display body has a polygonal shape in a two-dimensional plane perpendicular to the layer direction, The display according to claim 22 , wherein the first length direction is at an angle of 45° to one side of the polygon.

25. the image is a changing image that appears as a first image to an observer observing under a first observation condition, and appears as a second image different from the first image to an observer observing under a second observation condition different from the first observation condition; 22. The display according to claim 20, wherein the first observation condition and the second observation condition differ in at least one of a rotation angle, which is an angle by which the display is rotated by the observer from a reference state in a two-dimensional plane, and an observation angle, which is an angle between a line of sight from the observer to the display and a surface of the display, and the rotation angle is zero in the reference state.

26. the transparent layer is color-developing and turns black when irradiated with laser light; 22. The display according to claim 20, wherein the non-transparent portion is a portion of the transparent layer that has been blackened by irradiation with laser light.

27. A method for verifying authenticity of a display object described in claim 25 by confirming a changing effect in which the first image is visible when observed under the first observation conditions and the second image is visible when observed under the second observation conditions.

28. A core layer; a color-developing layer laminated on the core layer and which develops color when irradiated with laser light; an intermediate transfer unit laminated on the color-forming layer and having a first image printed thereon, the first image having a predetermined color pattern; a second image, different from the first image, drawn by irradiating the color-forming layer with laser light to cause color development in a desired portion of the color-forming layer; A display device that displays a desired color image by having the second image conceal the first image so as to prevent light from the core layer side from being incident on the first image.

29. 29. The display according to claim 28, wherein the first image is a group of color lines in which color lines of a plurality of colors that realize a color display are periodically arranged to form a line array.

30. 30. The display of claim 29, wherein the plurality of colors includes cyan, magenta, and yellow.

31. The display according to claim 30, wherein the plurality of colors further includes white.

32. 29. The display according to claim 28, wherein the predetermined color pattern is a one-dimensional color pattern.

33. 29. The display according to claim 28, wherein the predetermined color pattern is a two-dimensional color pattern.

34. Printing the first image includes: The display body of claim 28, which is produced by a pigment indirect transfer method in which a pigment ink ribbon is printed on an intermediate transfer film using a thermal head, and the intermediate transfer film on which the printing has been carried out is heat-sealed to the color-developing layer to form the intermediate transfer section.

35. 35. The display of claim 34, wherein the intermediate transfer film includes a hologram.

36. The display according to claim 34, wherein the intermediate transfer film includes a metal vapor deposition layer that can be removed by laser light.

37. 29. The display of claim 28, wherein the first image is a portrait outline of an owner of the display.

38. 30. The display of claim 28, wherein the first image includes an identification of an owner of the display.

39. The display according to claim 34, further comprising a transparent layer between the intermediate transfer film and the color-developing layer.

40. Preparing a core layer a color-developing layer that develops color when irradiated with laser light is laminated on the core layer; an intermediate transfer unit having a first image formed of a predetermined color pattern printed thereon is laminated on the color-developing layer; A method for creating a display body, which is created by irradiating the color-producing layer with laser light to cause the color-producing layer to produce color in a desired portion, thereby drawing a second image different from the first image so as to prevent light from the core layer side from being incident on the first image.

41. The creation method described in claim 40, wherein the printing of the first image is performed by a pigment indirect transfer method, in which a pigment ink ribbon is printed on an intermediate transfer film using a thermal head, and the printed intermediate transfer film is heat-sealed to the color-developing layer to form the intermediate transfer section.

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