JP2011025557A - Printed matter and authenticity verification method for printed matter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printed matter in which it is difficult to visually distinguish a latent image printing area included in a printing pattern and the latent image printing area of which can be visualized using a lens array sheet which is hardly acquired by the usual means in order to visualize the latent image, and an authenticity verification method for the printed matter. <P>SOLUTION: In the printed matter of which authenticity verification is performed using a lens array sheet having a plurality of micro-lenses regularly arranged on a surface plane, the printed matter has a pixel array area formed at the position corresponding to the arrangement of the micro-lenses, and the latent image printing area of pixels formed at the position shifted from the arrangement. The authenticity verification method for this printed matter is also provided. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a printed matter having a latent image that cannot be visually discerned in a printed pattern, and a method for verifying authenticity of the printed matter for verifying the latent image.

Stock certificates, gift certificates, etc. were usually provided to the market as elaborate printed materials using expensive printing devices to prevent counterfeiting and copying, but in recent years, holograms that prevent counterfeiting and copying are affixed. There are a wide variety of means for preventing forgery and duplication, such as a method of printing and a method of printing a part with an ultraviolet coloring material.
As a means for preventing the forgery and duplication, a method of incorporating a line image into a part of a pattern has been used. A latent image is printed by this line, the latent image is clearly reproduced, and further, a printed matter with a higher degree of freedom of the latent image and a visualization method thereof are provided (for example, see Patent Document 1). .
Further, as a display body and a labeled article having an excellent anti-counterfeit effect, including a plurality of unit display portions that are regularly arranged, each including a display pattern, and a plurality of lenses regularly arranged, A plurality of unit display units, and a plurality of unit display units, wherein the plurality of unit display units include a plurality of first unit display units that display the first image, and the display pattern includes the first display unit. One or more second unit display units that display a second image different from one image, and the display patterns of the plurality of unit display units and the plurality of lenses are superimposed on each other. Is arranged so as to display a composite image formed by combining a plurality of images displayed by the display patterns of the plurality of unit display units, and the second image is used as the composite image. Expansion of Without displaying an image, display body which displays an enlarged image of the first image at least one, it is provided (for example, see Patent Document 2).

JP 2004-174997 A JP 2009-86041 A

In the technique disclosed in Patent Document 1, the presence of a line portion is often visually discernible, and a line film used as a discriminating means can be obtained relatively easily. In addition, the clarity of the latent image when the line film is brought into close contact to reveal the latent image is low.
Further, the technique disclosed in Patent Document 2 is disadvantageous in that the medium and the lens array are integrated in order to make forgery and duplication difficult, so that the object is limited and the medium becomes expensive. As mentioned.
Therefore, the present invention uses a lens array sheet that is difficult to visually determine a latent image print area incorporated in a printed pattern and is difficult to obtain by ordinary means to visualize the latent image print area. An object of the present invention is to provide a “printed material and a method for verifying authenticity of the printed material” that can visualize the latent image printed region.

In order to achieve the above object, a first aspect of the present invention is a printed material that performs authenticity verification using a lens array sheet in which a plurality of microlenses are regularly arranged on a plane.
A pattern of the printed matter is provided with a pixel array region formed at a position aligned with the array of the microlenses and a latent image print region with pixels formed at a position shifted from the array. To do.

The second aspect is characterized in that, in the first aspect, the deviation from the arrangement of the microlenses is a phase deviation from the regular arrangement of the microlenses.

  The third aspect is characterized in that, in the first or second aspect, the pixel is a printed halftone dot.

  In the fourth aspect, the halftone dots printed in the latent image print area in the third aspect are approximately the same in number of halftone dots per unit area as the surrounding print portion of the latent image print area. The printing is performed in a state where dot angles and / or dot pitches are different.

The fifth aspect is a method for verifying the authenticity of a printed matter according to any one of the first to fourth aspects, wherein a lens is formed on a printed pattern in which a latent image printing region of the printed matter is formed. An array sheet is placed, a latent image is developed through the lens array sheet, and the authenticity of the printed matter is verified by whether or not the developed latent image has a predetermined pattern. is there.

1) As in the first aspect, in a printed matter that performs authenticity verification using a lens array sheet in which a plurality of microlenses are regularly arranged on a plane, the microlens is included in the design of the printed matter. Provided with a pixel array region formed at a position that matches the array of pixels and a latent image print region with pixels formed at a position shifted from the array. The halftone dots printed on the latent image printing area by the halftone dots printed on the pixels are the halftone dots per unit area with respect to the peripheral printing portion of the latent image printing area. The numbers are substantially the same, and printing with different halftone dot angles and / or halftone dot pitches makes it extremely difficult to visually determine the presence of a latent image incorporated in the design. Such a latent image can be incorporated into a pattern relatively easily by a printer (laser printer, thermal transfer printer, ink jet printer) or by normal printing.
2) Also, as in the fifth aspect, there is provided a method for verifying the authenticity of a printed matter according to any one of the first to fourth aspects, in which a latent image printing area of the printed matter is formed. By placing a lens array sheet on the design, developing a latent image via the lens array sheet, and verifying the authenticity of the printed matter by whether or not the expressed latent image is a predetermined pattern, By using a lens array sheet, it is possible to visualize a latent image in a pattern that is extremely difficult to distinguish visually. On the other hand, since it is extremely difficult to obtain a lens array sheet by ordinary means, the printed material can be provided as an inexpensive anti-counterfeit medium, and the authenticity of the printed material is determined by an easy-to-understand determination method with an inexpensive discrimination tool. A verification method can be provided.

It is a figure for demonstrating the printed matter of this Embodiment, and the authenticity verification method of printed matter. FIG. 2 is a diagram for describing a latent image printing area of any printing color of the printed pattern of the printed matter of FIG. 1 and a peripheral printing portion (hereinafter also simply referred to as a peripheral printing portion) of the latent image printing region. It is a figure for demonstrating the example in which a latent image does not exist in the latent image printing area | region of the printing color of any printing pattern of the printed matter of FIG. In the latent image printing region, the number of halftone dots per unit area is approximately the same as that of the surrounding printing portion, and is a diagram for explaining a state where the halftone angle or halftone pitch is different. It is a figure for demonstrating an example which patterned the latent image of the latent image printing area | region of the printing color of the printing pattern of the printed matter of FIG. It is a figure for demonstrating the CC cross section of FIG. It is a figure for demonstrating the density | concentration of a halftone dot.

With reference to FIG. 1 and FIG. 2, the printed matter of this Embodiment and the authenticity verification method of a printed matter are demonstrated.
Fig. 1 shows a latent image displayed on the surface of a lens array sheet by placing a lens array sheet on which a plurality of microlenses are regularly arranged on the surface of a printed material on which a latent image printing area is formed. It is the model which shows having been made. It can be seen that the A portion 11 that is the latent image printing region is expressed (visualized) in a predetermined shape on the surface of the lens array sheet 2 inside the B portion 12 that is the surrounding printing portion.

The design of the printed material 1 is printed in color (usually 3 to 4 colors), two colors, or one color, and the shade of the design is reproduced by the difference in the size of halftone dots.
Each lens of the lens array sheet 2 has one color among yellow (Y), red (R), and blue (B) constituting a pattern printed in multiple colors, for example, a halftone dot angle of a blue portion (hereinafter, referred to as “color”). The angle is adjusted to the pitch of halftone dots.
When the lens array sheet 2 is placed on the A portion 11 that is a latent image printing area and is moved to a predetermined position, each lens of the lens array sheet is placed at the center of the printed halftone dot. In order to focus, the surrounding printing portion (B portion in FIG. 1) 12 in FIG. 2 looks blue. The halftone dots formed in the latent image print area 11 that does not match the screen angle of the lens array sheet 2 are not present in the predetermined print area because no halftone dot exists at the focal point of each lens of the lens array sheet 2. Only (the halftone dot forming portion in the white figure of FIG. 2A) A portion 11 is expressed (displayed) in paper color.

In the following description, the portion of the design of the printed material 1 is described with a portion printed with a certain color. However, as described above, in the present invention, the subject of the invention is not limited to the printed material printed with one color.

FIG. 2A schematically shows a state in which the lens array sheet is removed from the portion where the latent image printing region 11 of the printed matter 1 of FIG. 1 is formed.
In FIG. 2, for ease of explanation, the above-described grid 3 schematically showing the “blue” screen angle is displayed in combination with the “blue” halftone dots of the printed portion.
For ease of explanation, only the halftone dots of the portion where the latent image print area 11 is formed are displayed with the color white. As shown in FIG. B, the actual printing portion is printed in the same print color in the latent image printing area 11 and the surrounding printing portion 12, and the latent image printing region 11 and the surrounding printing portion 12 are visually bordered. It is in a state that cannot be clearly identified.

With reference to FIG. 3 and FIG. 4, the difference between the latent image print area and the peripheral print unit will be described.
FIG. 3 shows the schematic grid 3 shown in FIG. 3d superimposed on the halftone dots and synthesized as a c-type for easy explanation.
A halftone dot (pixel) group printed in the latent image print area 11 shown in FIG. Are arranged in a “shifted phase”.
Here, “shift the phase” means to slightly translate or tilt (rotate) a group of pixels (halftone dots in the example of printed matter) in a predetermined direction.
In the example shown in FIG. 4, the halftone dot group printed in the latent image printing area 11 is arranged in a state where the halftone dot angle (phase) is different (shifted) from the halftone dot group printed on the peripheral printing unit 12. This is an example.

A halftone dot group having the same screen angle and the same pitch as that of the peripheral printing unit 12 is incorporated in the latent image printing area 11 shown in FIG.
2 is compared with FIG. 3, the number of halftone dots printed in the latent image print area 11 shown in FIG. 2 and the number of halftone dots printed in the latent image print area 11 shown in FIG. With the same number, the area of each halftone dot is the same.

As shown in FIG. 4, all of the halftone dots printed on the peripheral printing unit 12 are arranged and incorporated on the grid lines 31 having the halftone angle α shown in the figure. On the other hand, the halftone dot group printed in the latent image printing area 11 is arranged and incorporated on a lattice line 320 having the halftone dot angle β (the same as the angle of the lattice line 32).

That is, the halftone dots printed in the latent image print area 11 shown in FIG. 3c and the halftone dots printed in the latent image print area 11 shown in FIG. 4 (same as shown in FIG. 2a). In the group, the number of halftone dots and the pitch of the halftone dots are the same, but each halftone dot group printed in the latent image printing area 11 shown in FIG. 4 (the same as that shown in FIG. 2a) is displayed. The center of the halftone dot is in a state of being incorporated so that the halftone angle is different from the focal point of each lens of the lens array sheet as described above.
As a result, when the printed matter is visually observed, the latent image printing area 11 appears as a uniform area because the halftone dot density is the same as that of the surrounding printing portion 12 as described with reference to FIG.

As shown in the example of FIG. 2b, if there is a halftone dot that is close to the halftone dot printed in the peripheral printing unit 12 among the halftone dots printed in the latent image print area 11, Even if the halftone dots are deleted, they are visually recognized at the same density in the visual state. Therefore, the number of halftone dots printed in the latent image print area 11 is printed in the latent image print area 11 shown in FIG. It need not be exactly the same as the number of halftone dots created.
Further, in order to make the latent image print area 11 look like a predetermined pattern, a place where the focal point of the lens array sheet is not formed can be selected freely within the preset pattern area (halftone dot angle and / or halftone dot pitch is different). It is also possible to arrange halftone dots in the state (ie, not depending on the screen angle and the halftone pitch). In this case, the number of halftone dots arranged in the latent image printing area 11 is preferably the same as the number of grid intersections described in FIG.

With reference to FIG. 5, an example in which the latent image print region of any print color of the printed pattern of the printed matter of FIG. 1 is patterned will be described.
FIG. 5e is an enlarged view of the vicinity including the printed image latent image printing region 11 ′ and the surrounding printing unit 12. FIG.
When a lens array sheet (not shown) is placed on the diagram e, as shown in the diagram f, the halftone dots of the latent image printing area 11 'are displayed on the lens array sheet as "pattern M" (on the right side of the diagram f). It is expressed as shown).
In this area portion, 11 halftone dots constituting the latent image printing area 11 ′ are selected and arranged so as to be “pattern M”, and the halftone dots are grouped vertically outside the focus of the lens array sheet. In addition, “shift” results in the state shown in FIG. E, but it cannot be determined as “pattern M” in the visual state.

With reference to FIG. 6, the cross section along the line CC in FIG. 1 will be described.
The portion of the lens array sheet 2 in FIG. 6 is a cross section taken along the line CC in FIG.
A halftone dot 110 constituting a latent image and a halftone dot 120 of a peripheral printing portion are printed on the printing portion 1 on the back side of the lens array sheet 2 in FIG. The lens of the lens array sheet 2 located in the latent image printing area (A part) 11 reproduces and displays the color of the printed material base paper, and the lens array sheet 2 located in the peripheral printing part (B part) 12 On the lens, the color of the halftone dot 120 of the peripheral printing portion is reproduced and displayed.

In the lens array sheet 2 in which a plurality of microlenses are regularly arranged, in the example of FIG. 5, each lens has a focal length set to the thickness of each lens including a base portion (not shown). Yes. As a result, when the printed material is viewed from directly above the lens array sheet 2, the narrowest portion of the printed material is selected.
Therefore, as shown in FIG. 5, if the halftone dots 110 constituting the latent image are slightly out of the focal point of the lens array sheet 2, the lens array sheet states that “there is no halftone dot in the focal portion”. It is transmitted (expressed) to the surface of 2.
In the case of a lens having the same curvature as that of the lens shown in FIG. 5 and a thickness including the base portion that is thicker than the example of FIG. 5, the place to be focused becomes wide, and the halftone dots 110 constituting the latent image are slightly focused. Even if it is off, the halftone dot is picked up, and “there is a halftone dot at the focal point” is transmitted (expressed) to the surface of the lens array sheet 2.

Therefore, the curvature of each lens of the lens array sheet and the thickness of the lens array sheet greatly affect the determination accuracy when the authenticity of the printed matter is determined.
Further, as described above, the distance (lens pitch) between the centers of the individual lenses of the lens array sheet is matched with the pitch of the pixels (halftone dots) of the printed matter, and 120 to 175 in one inch. The microlenses are arranged at a certain interval (with a pitch of 0.21 to 0.14 mm). Note that up to 1.5 million micro lenses can be formed in one inch square.

With reference to FIGS. 7 and 6, the density of halftone dots will be described.
FIG. 7 is an enlarged view of the minimum unit on which the halftone dots of the printed portion around the printed material are printed.
The halftone dots shown in FIG. 7 indicate four halftone dots arranged on adjacent grid lines with a halftone angle of 30 degrees. The halftone dots are arranged at a pitch P.

  It is said that the lattice pattern is most noticeable when the screen angle is 0 degrees, and is least noticeable when the screen angle is 45 degrees. Therefore, the least noticeable yellow plate is set to 0 degrees, and the most noticeable black plate is set to 45 degrees. As a result, the blue and red plates are 15 or 75 degrees apart from the black plate by 30 degrees. The screen angle is a general setting and can be freely selected according to the purpose. In this embodiment, for ease of explanation, a case where the screen angle is 30 degrees will be described.

The density of halftone dots is represented by the ratio of the area of halftone dots contained inside the parallelogram to the area S of the parallelogram surrounded by a line connecting the centers of the four halftone dots in FIG. .
As can be seen from the figure, the sum of the areas of the four halftone dots included inside the parallelogram is equal to the area s of one halftone dot. Therefore, the density of halftone dots is represented by s / S.
6, the distance P from the center of the halftone dot to the center of the adjacent halftone dot is the same as P in FIG. 7, and the radius d of the halftone dot has the same meaning as d in FIG.
The distance between adjacent halftone dots is indicated by n. As a result, it can be expressed by P = 2d + n. The distance between adjacent lattice lines is indicated by h.

In the following, the relationship between the density of halftone dots and the P, d, n, h when the screen angle is 30 degrees in a circular dot screen will be described.
First, since (2d + n) / 2 = h / √3, h = (2d + n) √3 / 2 = 0.87 (2d + n), and the area S of the parallelogram connecting the center lines of the four dots is , S = (2d + n) h = 0.87 (2d + n) ² .
The area s of the halftone dots is expressed by s = πd ² .
From the above, when the halftone dot area is 50%, s / S = 0.5 and 3.14d ² /0.87(2d+n) ² = 0.5. From this, it becomes n = 0.697d.
Similarly, when the halftone dot area is 30%, n = 1.47d, and when the halftone dot area is 10%, n = 4d.

From the above, halftone dots having different screen angles or halftone dot pitches are arranged in the latent image print region, and the number of halftone dots is set to be approximately the same so that it is difficult to discriminate from the surrounding printing portion visually.
It can be seen that in the latent image printing region, the patterning operation is easier when the halftone dot density is higher than the higher halftone dot density, and the halftone dot density is preferably 50% or less, more preferably about 30 to 10%.

Further, from this, when a halftone dot group with a changed screen angle and / or halftone dot pitch is arranged in the latent image printing area and the lens array sheet is overlaid on the printed matter, as described in FIGS. In order to make the portion A look like a pattern, it can be seen from the aforementioned relationship of P, d, and n that the pattern choices become wider as the density of the halftone dots is lowered.
In this embodiment, the example of the circular dot screen has been described. However, the same result can be applied to other than the circular dot screen.

The printed matter and the method for verifying authenticity of the printed matter according to the present invention can be used for a wide range of print media from paper to non-paper.

DESCRIPTION OF SYMBOLS 1 Printed matter 2 Lens array sheet 3 Grid 11, 11 'A part, latent image printing area 12 B part, surrounding printing part 31 Grid line 32 of halftone angle (alpha), 320 Grid line 110 pixel of halftone angle (beta) 120 pixels of halftone dots composing the latent image, halftone dots of the printed peripheral printing part

Claims (5)

In a printed matter that performs authenticity verification using a lens array sheet in which a plurality of microlenses are regularly arranged on a plane,
A pattern of the printed matter is provided with a pixel array region formed at a position aligned with the array of the microlenses and a latent image print region with pixels formed at a position shifted from the array. To print. The printed matter according to claim 1,
The printed matter, wherein the deviation from the arrangement of the microlenses is a phase deviation from the regular arrangement of the microlenses. In the printed matter according to claim 1 or 2,
The printed matter, wherein the pixel is a printed halftone dot. The printed matter according to claim 3,
The halftone dots printed in the latent image print area are printed in a state where the number of halftone dots per unit area is approximately the same, and the halftone angle and / or the halftone dot pitch are different with respect to the peripheral printing portion of the latent image print area. Printed matter characterized by that. A method for verifying authenticity of a printed matter for verifying authenticity of the printed matter according to any one of claims 1 to 4,
A lens array sheet is placed on a printed pattern on which a latent image printing area of the printed material is formed, and a latent image is developed through the lens array sheet. Depending on whether or not the developed latent image is a predetermined pattern, A method for verifying authenticity of printed matter, wherein authenticity is verified.

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