JP3431107B2 - Hidden image - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hidden image which is difficult to visually recognize before copying, but when copied, characters such as "copy prohibited" appear on the copy paper so that they can be visually recognized.

[0002]

2. Description of the Related Art Conventionally, as a printed matter for which copying is desired to be prevented, there has been provided a hidden image provided on the surface of a sheet such that when copying, a "copy prohibited" character or the like appears on the copy paper with the naked eye. ing. The hidden image is generally divided into two sections, a first section that constitutes a character such as a "copy prohibited" character and a graphic that indicates that copying is desired to be prevented, and a second section that constitutes a background around the character. Consists of. The first section is a number of hidden images of the first pattern
Consists forming element, said second compartment Ru hidden imaging element of the plurality of second pattern Tona. The hidden image is formed on the sheet by printing the large number of the first and second patterns of the hidden image forming element on the sheet.

[0003] In the first and the first compartment and second compartment by a sheet forming the hidden image that Do from hidden image forming element of the second pattern, the distinction between the first compartment and the second compartment stick to the naked eye So that there is no unit area on the sheet,
Total area of a hidden imaging element of the second pattern sum and a plurality of areas of a hidden imaging element of the plurality of first pattern is formed to be equal to each other, whereas, if the copy the sheet For example, on the copy paper, the character part
The interval between the plurality of hidden image forming elements of the first pattern and the plurality of the second pattern so that there is a density difference that can be visually distinguished between the ( first section) and the background portion (second section) . The spacing of the hidden imaging elements are formed with different dimensions.

Examples of such a hidden image include Japanese Patent Publication No. 64-5835 and Japanese Patent Publication No. 2-517.
42, JP-B-3-32974, and JP-A-63.
The ones disclosed in JP-A-62797 and JP-A-2-29679 are conventionally known. That is, in JP-B-64-5835, JP-B-2-51742, and JP-B-3-32974, the number of hidden image forming elements of the first pattern and the hidden image forming elements of the second pattern are disclosed. Different from each other, and accordingly
There is disclosed a hidden image in which the size of each hidden image forming element of the pattern and the size of each hidden image forming element of the second pattern are different from each other. In addition, JP-A-2-2967
JP-A-63-62797 and JP-A-63-62797 vary the contact ratio of each hidden image forming element between the first pattern and the second pattern, and accordingly, for forming each hidden image of the first pattern. A hidden image in which the size of the element and the size of each hidden image forming element of the second pattern are different from each other is disclosed.

[0005]

However, when the first pattern and the second pattern having the above-mentioned hidden image forming element in the prior art are offset printed on a sheet, for example, FIGS. 7 (a) and 7 (b) are used. As shown in, due to the so-called dot gain in which the ink spreads outward when the ink is transferred from the printing original plate to the sheet, the ink is transferred from the contour 100 of the hidden image forming element on which the ink on the printing original plate is placed. The contour 101 of the hidden image forming element on the formed sheet is slightly larger.
Moreover, the degree to which the contour 101 of the hidden image forming element on the sheet increases due to the dot gain increases as the contour 100 of the hidden image forming element on the printing original plate increases. Therefore, when the sizes of the hidden image forming elements forming the first and second patterns are different from each other, like the conventional hidden images disclosed in the above-mentioned five publications, the size of the hidden image forming elements on the sheet is different. There is a difference in the total area of the hidden image forming elements of each pattern, which causes a density difference that can be visually distinguished between the first section and the second section on the sheet. As a result, there is a problem that the printed contents on the printed matter are adversely affected, and it is easily known that the sheet has a hidden image.

Further, when the interval between the hidden image forming elements of the first and second patterns is small, when the ink is transferred from the printing original plate to the sheet due to the surface tension of the ink placed on the printing original plate. A space between the two hidden image forming element portions is filled with ink, which causes a so-called tone jump in which two hidden image forming elements are connected to each other on the sheet. For this reason, JP-A-2-29679 and JP-A-63-627.
If the hidden image forming elements are in contact with each other in one pattern and the hidden image forming elements are apart from each other in the other pattern, as in the conventional hidden image disclosed in Japanese Patent Laid-Open No. 97, for example, as shown in FIG. ), A tone jump occurs only in the pattern in which the hidden image forming elements are in contact with each other, and the outline 102 of the pattern portion where the hidden image forming elements are in contact with each other on the sheet is increased, The difference in the total area of the hidden image forming elements of the first and second patterns on the sheet is further increased.
Therefore, the density difference between the first section and the second section on the sheet becomes large. As a result, the printed contents on the printed matter are more adversely affected, and it is more easily recognized that the sheet has a hidden image.

The present invention has been made in view of the above circumstances, and an object of the present invention is to make it difficult to visually distinguish the first section and the second section on a sheet before copying, and moreover, when copying. Is to provide a hidden image that can be reliably discriminated from the first section and the second section on the copy paper with the naked eye.

[0008]

In order to achieve the above-mentioned object, the present invention provides a method for forming a hidden image having a large number of first patterns.
A first section formed by arranging elements and a second section formed by arranging a large number of hidden image forming elements of a second pattern
And one of the first section and the second section.
Are characters such as letters and figures, and the other is character
In the hidden image formed by composing the background data, the hidden image forming element of the first pattern, multiple <br/> number consisting of bent band-like region having a width and a predetermined length of Jo Tokoro Of the first component , the band-shaped region forming each of the first components is bent to form at least one first recess , and The hidden image forming element of the second pattern comprises a bent strip-like region having a width and length substantially similar to those of the first constituent element.
The plurality of second constituent elements are combined, and the band-shaped region forming each of the second constituent elements is bent.
In forms at least one second recess, said first recess, while being formed with a predetermined width that is reproduced in its original shape state upon copying, the second recess, copying sometimes the original shape is formed in a narrow predetermined width, as reproduced in the state can not be determined, further, one of the first pattern
A plurality of the first elements constituting a hidden image forming element
Components of the contour length of the sum and one of the second pattern a hidden imaging element a plurality of the second constituting a
The sum of the lengths of the contour lines of the components is almost equal, and
Comprising one said first pattern of hidden imaging elements
And the sum of the areas of the plurality of first constituent elements and one before
Double constituting the a hidden imaging element of the serial second pattern
It is characterized in that the total area of the second component of the number is formed to be substantially equal.

Further, in the present invention, the hidden image forming element of the first pattern is formed by substantially connecting four first constituent elements, and the hidden image forming element of the second pattern is four. It is assumed that the two second constituent elements are substantially connected. Also, the present invention is directed to each of the adjacent first
The end portions of the constituent elements of (1) intersect at substantially right angles, and the end portions of the adjacent second constituent elements also intersect at substantially right angles. Further, the present invention, the each first component, said first recess is formed one each, to the each second configuration element, said second recess is a plurality formed I decided. The present invention also depth of the first recess, larger than the depth of the second recess
It was heard stuff.

[0010]

The total sum of the lengths of the line segments connecting the outer circumference and the inner circumference of each hidden image forming element of the first and second patterns, and the first and second
The hidden image forming elements of the second pattern are configured so that the sum of their areas is equal to each other.
A plurality of hidden image forming elements constituting one pattern
The sum of the lengths of the contour lines of the first component and one second pattern
A plurality of second parts constituting the hidden image forming element 8
And the total length of the contour lines of the
One, one first pattern of hidden imaging element
The sum of the areas of the plurality of first components and one second
A plurality of first elements that make up the hidden imaging element of the pattern.
Because the total area of the second component are substantially equal, the first, at the hidden image forming element of the second pattern indicia <br/> printed on a sheet, even if dot gain and doubling occurs,
First, hidden imaging core of the second pattern on the sheet
The degree to which the outline of the element becomes large is the same as each other, and it is difficult to discriminate with the naked eye. Then, when copying is performed, the first concave portion formed on the first constituent element of the first pattern is reproduced in the original shape state on the copy paper, but is formed on the second constituent element of the second pattern. By reproducing the second concave portion in a state where the original shape cannot be discriminated, a density difference occurs between the first pattern and the second pattern, and the second concave portion can be visually discriminated.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to an embodiment shown in the drawings. FIG. 1 is a plan view showing a copy-preventing printed material provided with a hidden image according to an embodiment of the present invention. The copy-preventing printed material 1 includes a sheet 2, a hidden image 3 according to the present invention which is formed on the surface of the sheet 2 and appears on a copy sheet when a copy is made, and print contents printed on the hidden image 3 (not shown). ) And is composed of. The hidden image 3 is formed by a character portion (corresponding to the first section) 4 such as "copy prohibited" and a background portion (corresponding to the second section) 5 indicating that copying is desired to be prevented. The character portion 4 and the background portion 5 are formed in a pattern of a large number of fine squares (for example, one piece is 0.4 mm) having the same size (details will be described later). Further, the hidden image 3 is formed on the copy-preventing printed matter 1 by offset printing or the like.

[0012] 2 (a) is an explanatory diagram showing hidden imaging element of the first pattern constituting the character part of the hidden image 3 formed on the sheet over sheet 1 4 (first compartment), 2 (B)
Is the second part of the background part (second section) of the hidden image 3 .
It is explanatory drawing which shows the hidden image forming element of a pattern , and for the hidden image formation of each pattern shown to FIG. 2 (a), (b) .
Each element represents one unit. As shown in FIG. 2A, the hidden image of the first pattern that constitutes the character portion 4
The forming elements 6 each have a predetermined width ( for example, 0.02 m).
m) and consisting of bent band-like region having a predetermined length, a combination of four of the first component 7 equal
The two adjacent ends of each first component 7 are connected at right angles. I each first component 7
By bending the strip-shaped regions, each has a predetermined width W ₁ (for example, 0.04 mm) and a predetermined depth dimension.
With L ₁ (eg 0.32 mm), hide the first pattern.
First recess 7a recessed inward of the image-forming element 6
The forms one hidden image consisting of four components 7
The overall shape of the image forming element 6 is substantially swastika when viewed from the back side of the drawing.

Further, as shown in FIG. 2B , the hidden image forming element 8 of the second pattern forming the background portion 5 is
Each the same width and length as the first component 7 of the character part 4
Consisting bent band-like region having four is constituted by combining the second component 9 equal, adjacent opposite ends of the respective second component 9 is connected at a right angle. The strip-shaped regions forming each second component 9 are bent.
Doing, shallower than the depth of the first recess 7a respectively on both sides (i.e., the depth dimension L ₂ is first recess
Narrow width ( smaller than the depth dimension L _{1 of} 7a ) (almost the same width as the width of the strip-shaped region forming the second component 9)
A second recess 9a have multiple forms. (In other words
For example, each second recess 9a is formed with a predetermined width W ₂ (<W ₁ ) and a predetermined depth dimension L ₂ (<L ₁ ). In this embodiment, the second recess 9a is formed to have a depth (depth dimension) less than half that of the first recess 7a and a width almost half that of the first recess 7a. Further, the first concave portion 7a is formed with a predetermined width so that the original shape can be reproduced on the copy paper when copying is performed, and the second concave portion 9a is formed on the copy paper when copying is performed. Is formed with a predetermined width so that the original shape can be reproduced without being crushed. Further, the first constituent element 7 and the second constituent element 9 are formed to have substantially the same size on the outer peripheral surface, and further, the first and second constituent elements 7 and 9 are formed.
The total sum of the lengths of the line segments connecting the outer circumference and the inner circumference of the portions formed by and the total area of the portions formed by the first and second constituent elements 7 and 9 are also the same. Is formed in. That is, one first pattern
Four first structures constituting the hidden image forming element 6 of
Of the total length of the contour lines of component 7 and one of the second patterns
Four second configurations making up the hidden imaging element 8
So that the sum of the lengths of the contour lines of element 9 is almost equal
Hidden image of the first pattern that has been formed
Of the four first components 7 making up the forming element 6
Total area and one second pattern hidden image forming element
Sum of the areas of the four second constituent elements 9 constituting
Togaho are formed to be equal pot. For this reason,
Hidden imaging element 6 of the first pattern and the second pattern
When offset printing the hidden image forming element 8 on the sheet 2, as shown in FIGS. 3A and 3B, dot gain (ink spreads to the outside of the printing original plate during printing) 1
0a, 10b occur, or in FIG. 4 (a), (b)
As shown in FIG. 4, even if the double-printing (the original printing and the transfer of the ink remaining on the blanket again) 11a, 11b occurs, the first component 7 and the second component 9 on the sheet 2 The degree to which the contour becomes large depends on whether the first pattern is hidden.
The image forming element 6 and the hidden image forming element of the second pattern
Element 8 is the same as each other. The doubles shown in FIGS. 4A and 4B are examples in the vertical direction. Therefore, the first pattern
And a second character portion 4 composed of the hidden image forming element 6 of
The background portion 5 composed of the hidden image forming elements 8 of the pattern cannot be discriminated by the naked eye, and only the print content (not shown) printed on the hidden image 3 is displayed on the sheet 2. . Then, when this sheet 2 is copied by an electrostatic copying machine, the second concave portion 9a formed in the second component 9 is formed.
Since the original shape is formed so narrow that the original shape cannot be discriminated, it is reproduced on the copy paper as shown in FIG. Since the first concave portion 7a of the constituent element 7 is formed with a width that allows the original shape to be discriminated, the second concave pattern 7a can be reproduced without being crushed on the copy paper to obtain the second pattern.
It is formed by a hidden imaging element 6 of the first pattern of the background portion 5 composed of hidden imaging element 8 of
Was than character portion 4, the concentration amount corresponding to the second concave portion 9a is collapsed darker, superimposed on the print contents (not shown) character portion 4 stood out.

[0014] FIG. 6 (a), (b) includes a first pattern hidden imaging element 6 constituting the character portion content of the hidden image according to another embodiment of the present invention, respectively, constituting the background portion It is explanatory drawing which shows the hidden image forming element 8 of a 2nd pattern, and shows the 1st, 2nd pattern of FIG. 2 (a), (b) .
The same parts as the hidden image forming elements are designated by the same reference numerals,
The description is omitted. In this embodiment, the bottom portion 7b of the first recess 7a of each first component 7 and each second component 9 are formed.
In the bottom portion 9b of the arbitrarily selected second recess 9a, the gaps 12a and 12b having substantially the same width as the width of the second recess 9a, respectively.
Is provided, and other configurations are the same as those in the above-described embodiment. Also in this embodiment, the first
Character part composed of the hidden image forming element 6 of the pattern
4 and made up of hidden imaging element 8 of the second pattern
Although it cannot be distinguished from the background portion 5 with the naked eye, when copying is performed, the hidden image 3 appears on the sheet 1 due to a density difference between the character portion 4 and the background portion 5 when copying on a copy paper.

[0015]

As described above, according to the present invention, a first section formed by arranging a large number of hidden image forming elements of a first pattern and a large number of hidden image shapes of a second pattern.
It consists of a second section where the production elements are arranged,
One of the first section and the second section has
Make up the character, the other makes up the background of the character
In the hidden image formed by Rukoto, hidden imaging element of the first pattern, the width and a predetermined length of Jo Tokoro
A plurality of first components comprising bent strip regions having
Are combined to form each of the first constituent elements .
The strip-shaped region is bent to form at least one first region .
Forms a recess, the hidden image forming element of the second pattern, a plurality of second component consisting of bent band-like region having substantially the same width and length as the first component It is configured by combining the above-mentioned second constituent elements .
The band-shaped region is formed by bending to form at least one second concave portion , and the first concave portion is formed with a predetermined width so as to be reproduced in the original shape state at the time of copying. the second recess, the original shape is formed in a narrow have a predetermined width, as reproduced in a state which can not be determined at copying, further for a concealed image formation of one of the first pattern
Of the contour lines of a plurality of said first components that make up the element
The length of the sum and one of the second pattern a hidden length of the contour line of the plurality of the second component constituting the imaging element sum and almost equal to, and, one of said first Patta
A plurality of said first elements constituting the hidden imaging element of the scene.
The total area of one constituent element and the plurality of second constituent elements constituting one hidden image forming element of the second pattern.
And total area of the element has a configuration that is formed to be substantially equal. For this reason, it is possible to make it difficult for the naked eye to distinguish between the first section and the second section that make up the hidden image on the sheet provided with the hidden image according to the present invention. The second section can be easily identified with the naked eye.

[Brief description of drawings]

FIG. 1 is a plan view showing a copy-preventing printed matter to which a hidden image according to the present invention is applied.

FIG. 2A is a diagram showing a pattern of a character portion of a hidden image according to an embodiment of the present invention, and FIG. 2B is a diagram showing the background portion thereof.

3 (a) and 3 (b) are diagrams showing respective patterns of a character portion and a background portion when a dock gain occurs.

FIG. 4A and FIG. 4B are diagrams showing respective patterns of a character portion and a background portion when a double image is produced.

FIG. 5 is a diagram showing a pattern of a background portion at the time of copying.

FIG. 6A is a diagram showing a pattern of a character portion of a hidden image according to another embodiment of the present invention, and FIG. 6B is a diagram showing the background portion thereof.

FIG. 7A is a diagram showing an example of a pattern of a character portion of a hidden image according to a conventional example, and FIG. 7B is a diagram showing an example of a pattern of a background portion thereof.

[Explanation of symbols]

1 Copy protection printed matter 3 hidden images 4 character part 5 background 6 First pattern 7 First component 7a First recess 8 second pattern 9 Second component 9a Second recess

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-1-167870 (JP, A) JP-A-6-247089 (JP, A) JP-A-8-25790 (JP, A) Actual Kaihei 4- 67667 (JP, U) Actual development Sho 59-99773 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) B41M 3/14 B42D 15/10 531

Claims (5)

(57) [Claims] 1. A plurality of first pattern hidden image forming elements are required.
A first section formed by arranging elements and a second section formed by arranging a large number of hidden image forming elements of a second pattern
And one of the first section and the second section.
Are characters such as letters and figures, and the other is character
In the hidden image formed by composing the background data, the hidden image forming element of the first pattern, Jo Tokoro width 及
And a plurality of first constituent elements each including a curved strip-shaped area having a predetermined length are combined, and the strip-shaped area forming each of the first constituent elements is bent.
It forms at least one first recess in said hidden image forming element of the second pattern, curved strip has substantially the same width and length as the first component
The plurality of second constituent elements each of which is composed of a region are combined, and the strip-shaped region forming each of the second constituent elements is bent.
Forms at least one second recess by said first recess, while being formed with a predetermined width that is reproduced in its original shape state upon copying, the second recess, It is formed with a narrow predetermined width so that the original shape can be reproduced in a state where it cannot be discriminated during copying, and one hidden pattern forming element of the first pattern.
The lengths of the contour lines of the plurality of first constituent elements that make up
A hidden imaging element of the sum and one of the second pattern
And the total sum of the lengths of the contour lines of the plurality of second constituent elements is substantially equal, and one first pattern
A plurality of the first structures constituting the hidden image forming element of
And the sum of the areas of a plurality of said second component constituting the a hidden imaging element of the sum and one of said second pattern area of formation elements are formed to be substantially equal, that Hidden image to feature. 2. The hidden image forming element of the first pattern is formed by substantially connecting four of the first constituent elements,
The hidden image according to claim 1, wherein the hidden image forming element of the second pattern is formed by substantially connecting four of the second constituent elements. 3. The hidden image according to claim 2, wherein the ends of the adjacent first constituent elements intersect at substantially right angles, and the ends of the adjacent second constituent elements also intersect at substantially right angles. . The method according to claim 4, wherein each of the first component, said first recess is formed one each, <br/> the each second configuration elements, a plurality said second recess, respectively The hidden image according to claim 1, wherein the hidden image is formed. Depth of 5. Before Symbol first recess, the second according to any one of claims 1 to greater than the depth dimension of the recess or 4, wherein the hidden image.