JP7224587B2 - Transmission latent image forming member - Google Patents

Description

INDUSTRIAL APPLICABILITY In the field of valuable printed matter such as banknotes, passports, negotiable securities, identification cards, transit tickets, etc., which require an anti-counterfeiting effect, the present invention provides a transmission latent image that changes when tilted under transmitted light. It relates to an image forming body.

With the recent development of digital devices such as scanners, printers, and color copiers, it has become possible to easily produce elaborate copies of valuable printed materials. Therefore, in order to prevent duplication and forgery by the above-mentioned digital equipment, various forgery prevention techniques that cannot be reproduced by printers and copiers are required.

As one of the anti-counterfeiting techniques, there is a so-called watermarking technique in which a pattern is formed by varying the density and thickness of paper and is visible under transmitted light. As an example of such a watermarking technique, a technique of thickening and thinning paper by using a cylinder or a dandy roll in which a watermark pattern is formed as an uneven shape on a roll member has been used for a long time. Observation of a relatively thin portion of the paper formed by a circular net or a dandy roll under transmitted light reveals a higher amount of transmitted light and a brighter image, while a relatively thicker portion of the paper is viewed under transmitted light. When viewed from below, the amount of transmitted light is reduced and it appears dark.

This watermarking technology makes the pattern invisible under normal reflected light. It is widely used in the field of valuable printed matter because it is possible to distinguish between authenticity and high name recognition.

In addition, as a technique for forming watermarks based on the density and thickness of paper, processed paper products have been proposed in which watermarks are formed by removing the paper material using laser processing in order to express the intermediate gradation of photographs, paintings, etc. (See Patent Document 1, for example). The technique of Patent Document 1 forms a watermark with gradation by varying the depth and size of the depressions formed by laser processing according to the gradation of the original image.

On the other hand, the present applicant has proposed an authenticity discriminating formed body in which not only the pattern can be visually recognized under transmitted light, but also the image changes when observed at an angle, like the watermark technology (for example, Patent Document 2). reference). In addition, in the technique of Patent Document 2, a perforation penetrating the base material is used as a reference position, and a non-through hole arranged in a specific direction is formed so as to overlap a part of the perforation penetrating the base material, and is tilted under transmitted light. A latent image is visible when observed with a finger.

JP-A-2000-006597 Japanese Patent No. 3873211

However, although the technique of Patent Document 1 is a technique that allows a watermark with rich gradation to be visually recognized by observing it under transmitted light, the image does not change when observed at an angle.

Further, the technique of Patent Document 2 is a technique in which a latent image can be visually recognized when obliquely observed under transmitted light by arranging through-hole groups and non-through holes corresponding to the through-holes constituting the through-hole groups. However, when a non-through hole formed corresponding to the design of the latent image is formed in the paper substrate, the non-through hole is thinner than the processed part of the paper substrate and has high light transmittance. Therefore, there is a problem that the design of the latent image is visible before tilting.

Further, the technique of Patent Document 2 has a configuration in which through holes and non-through holes are combined into one and an image is formed by arranging a plurality of such holes. Although it is necessary to provide many through holes and non-through holes inside, there is a problem that the strength of the base material is lowered. Conversely, when the strength of the base material is prioritized, processing must be performed with a certain amount of space between the through holes and the non-through holes, in which case the resolution of the latent image is lowered.

An object of the present invention is to solve the above-mentioned problems. To provide a transmissive latent image forming body which suppresses a decrease in the strength of a material and has a high hiding property for a latent image which is obliquely viewed under transmitted light.

In the transmission latent image forming member of the present invention, a watermark pattern is formed on at least a part of the substrate, and the watermark pattern is formed by forming a plurality of concave first watermark elements having higher transparency than the substrate. A transmission latent image pattern comprising a latent image portion and a background portion in which a plurality of concave second watermark elements having higher transparency than the substrate is formed. The configuration in which the image portion and the background portion have the same transparency is i) the area ratio of the first watermark element formed in the latent image portion is higher than the area ratio of the second watermark element formed in the background portion, and , the depth of the second watermark element is greater than the depth of the first watermark element, or ii) the depth of the second watermark element is the same as the depth of the first watermark element, and A configuration in which the size and pitch of the first watermark element are larger than those of the second watermark element, or iii) the first watermark element and the second watermark element are lines having the same area ratio and depth, The first watermark element formed in the latent image area and the second watermark element formed in the background area are arranged in different directions. The latent image is visually recognized due to the difference in the amount of transmitted light between the portion and the background portion.

Further, in the transmission latent image forming member of the present invention, the latent image portion and the background portion have the configuration of i), and the latent image portion is formed with the first watermark elements having different sizes and depths. , a first latent image portion, a second latent image portion, . The size of the first watermark element is smaller and the depth of the first watermark element is deeper in the order of the latent image portion, . . . , the n-th latent image portion. The pattern of the latent image changes and is visually recognized depending on the viewing angle.

Further, in the transmission latent image forming body of the present invention, a watermark pattern is formed on at least a part of the base material, and the watermark pattern is formed by watermark ink and the first watermark element having higher transparency than the base material. A transmission latent image pattern comprising a plurality of latent image portions and a background portion in which a plurality of concave second watermark elements having higher transparency than the substrate is formed, wherein the transparency of the latent image portion and the background portion is provided. are equal, and when the substrate is tilted and observed under transmitted light, the latent image is visually recognized due to the difference in the amount of transmitted light between the latent image portion and the background portion.

Further, in the transmission latent image forming member of the present invention, the watermark pattern is formed from the substrate at a position not overlapping the first watermark element formed in the latent image area and the second watermark element formed in the background area. a transmission pattern formed by forming a plurality of concave-shaped third watermark elements having a high transparency, wherein the size of the third watermark element is equal to or smaller than the size of the second watermark element; The depth of the watermark element is equal to or greater than the depth of the second watermark element, and the transmitted pattern and the latent image change and are visually recognized depending on the angle at which the substrate is observed under transmitted light.

In the transmission latent image forming member of the present invention, since the latent image portion forming the transmission latent image pattern in which the latent image is visually recognized and the background portion have the same transparency, the latent image concealability is high.

In addition, since the transmission latent image forming body of the present invention forms a transmission latent image pattern in which the latent image is visually recognized by watermarking without forming through holes in the substrate, the strength of the substrate is reduced. can be suppressed.

1 is a diagram showing an outline of a transmission latent image forming member of the present invention; FIG. 4A and 4B are diagrams showing the structure of a transmission latent image pattern according to the first embodiment; FIG. FIG. 2 is a diagram showing a state observed under transmitted light from a position directly facing the transmission latent image forming body, and a visible watermark. FIG. 2 is a diagram showing a state of observation under transmitted light from an oblique direction with respect to the transmission latent image forming body, and a visible watermark. FIG. 3 is a diagram showing the configuration of a latent image portion and a background portion that form a transmission latent image pattern; FIG. 10 is a diagram showing another configuration of the latent image portion and the background portion that form the transmission latent image pattern; FIG. 10 is a diagram showing an example in which a latent image portion and a background portion are composed of a watermark element composed of image lines; FIG. 10 is a diagram showing an example in which a latent image portion and a background portion are composed of a watermark element composed of dashed lines; FIG. 10 is a diagram showing an outline of a transmission latent image forming member according to a second embodiment; FIG. 10 is a diagram showing the structure of a watermark pattern according to the second embodiment; FIG. FIG. 10 is a partially enlarged view of the watermark pattern of the second embodiment, showing the configuration of the transparent pattern; FIG. 10 is a diagram showing the structure of a third watermark element forming a transparent pattern; FIG. 10 is a diagram showing an outline of a transmission latent image forming member of a third embodiment; FIG. 10 is a diagram showing the structure of a latent image portion forming a transmission latent image pattern according to the third embodiment; It is a figure which shows the structure of the 1st latent-image part which comprises the latent-image part of 3rd Embodiment. FIG. 10 is a diagram showing the configuration of a second latent image portion that constitutes the latent image portion of the third embodiment; FIG. 10 is a diagram showing the configuration of a third latent image portion that constitutes the latent image portion of the third embodiment; FIG. 11 is a diagram showing another configuration of the latent image portion of the third embodiment;

Modes for carrying out the present invention will be described with reference to the drawings. and various other forms.

(First embodiment)
First, the outline of the transmission latent image forming member (1) of the first embodiment of the present invention will be described with reference to FIG. The transmission latent image forming body (1) shown in FIG. 1 has a watermark pattern (7) visible under transmitted light on at least a part of a light-transmitting substrate (2) such as paper, In the first embodiment, the watermark pattern (7) comprises a transparent latent image pattern (7A) consisting of a latent image portion (3) and a background portion (4).

The substrate (2) used in the present invention may be in the form of a light-transmitting sheet, such as paper, synthetic fiber paper, non-woven fabric, film, or card substrate. Specifically, wood fibers such as conifers and broadleaf trees, paper made from non-wood fibers such as kenaf, bagasse, abaca, hemp, cotton, mitsumata, kozo, straw, and bamboo, recycled fibers such as rayon, polyvinyl alcohol, polyethylene, It is possible to use synthetic fiber paper or non-woven fabric made of synthetic fibers such as polystyrene, PET, and polyolefin. However, when the substrate (2) such as a film or card is used, the material must be able to adjust the light transmittance by adjusting the thickness of the substrate.

In the present invention, the watermark pattern (7) is, for example, formed in a concave shape by partially varying the thickness of the substrate (2) in the same manner as in the conventional watermark structure. (7) is invisible under reflected light but visible under transmitted light. Further, in the watermark pattern (7) of the present invention, the pattern that can be visually recognized changes by changing the observation direction under transmitted light, and the pattern of the latent image portion (3) (here, the letter "N") is visually recognized. characterized by being able to A detailed configuration of the transmission latent image pattern (7A) will be described below.

(Transmission latent image pattern)
FIG. 2(a) shows a plan view of a transmissive latent image forming member (1) in the present invention, and is an enlarged view of the broken line area in FIG. FIG. 2(b) is a cross-sectional view taken along line AA' of FIG. 2(a). The transmission latent image pattern (7A) shown in FIG. 2 is an example of a concave configuration.

As shown in FIG. 2(a), the latent image portion (3) forming the transmission latent image pattern (7A) has a concave first watermark element (5) on one surface of the substrate (2). The background part (4) has a plurality of concave second watermark elements (6) arranged on the same surface where the first watermark elements (5) are formed on the base material (2). It consists _The latent image portion (3) shown in FIG _. 1 shows an example in which they are arranged at a constant pitch (P _y 1) in a second direction (V _y 1) different from the first direction. By arranging the first watermark elements (5) at a constant pitch (P _x 1, P _y 1) in this manner, the latent image portion (3) is a watermark with uniform brightness under transmitted light. , and the latent image portion (3) can be hidden due to the transparency relationship with the background portion (4), which will be described later. The direction in which the first watermark element (5) is arranged is not limited to the direction shown in FIG. 2 as long as it is different.

Also, the _{background portion} (4) shown in FIG. An example is shown in which they are arranged at a constant pitch (P _{y 2) in a second direction (V y 2} ) different from the first direction. The background part (4) is also visible as a watermark with uniform brightness under transmitted light by arranging the second watermark elements (6) at a constant pitch (P _x 2, P _y 2). The latent image portion (3) can be concealed due to the transparency relationship with the latent image portion (3), which will be described later. The direction in which the second watermark element (6) is arranged is not limited to the direction shown in FIG. 2 as long as it is different.

In the latent image portion (3) shown in FIG. 2, the first watermark elements (5) are arranged at a constant pitch (P _x 1, P _y 1), but the first watermark elements (5 ) may be randomly arranged at different pitches to make the latent image portion (3) uniform in brightness under transmitted light. The same applies to the second watermark elements (6) arranged in the background part (4). 4) may be uniform brightness.

Although the first watermark element (5) and the second watermark element (6) shown in FIG. 2 illustrate an example consisting of a circular configuration, the first watermark element (5) and the second watermark element (5) (6) is not limited to a circular shape, and may be various figures such as triangles, polygons including quadrilaterals, star shapes, letters, symbols, numerals, and the like. Also, the first watermark element (5) and the second watermark element (6) may be in the form of streaks. Also, the first watermark element (5) and the second watermark element (6) may have different shapes, for example, the first watermark element (5) is circular and the second watermark element (6) is triangular. Alternatively, the first watermark element (5) may be straight and the second watermark element (6) may be rectangular. Here, an example is described in which the first watermark element (5) and the second watermark element (6) are of circular configuration, and the first watermark element (5) and the second watermark element (6) are , and the construction of the streaks will be described later.

In the present invention, the latent image portion (3) and the background portion (4) have the same transmittance. However, when the base material (2) is tilted and observed under transmitted light, the pattern of the latent image portion (3) is visible because only the light is transmitted through the latent image portion (3). A configuration that satisfies this effect will be described in detail.

The first configuration that satisfies the effects of the present invention is, as shown in FIG. The depth (H2) of the concave shape is large, and the area ratio of the first watermark element (5) is higher than the area ratio of the second watermark element (6). In the present invention, the "area ratio of the first watermark element (5)" means the ratio of the area of the first watermark element (5) formed per unit area of the base material (2). "The area ratio of the second watermark element (5)" means the ratio of the area of the second watermark element (6) formed per unit area of the substrate (2). Needless to say, the relationship between the depth and the area ratio of the first watermark element (5) and the second watermark element (6) may be reversed to the condition described above. That is, the depth (H2) of the concave shape of the second watermark element (6) is shallower than the depth (H1) of the concave shape of the first watermark element (5), and The area ratio of (5) may be lower than the area ratio of the second watermark element (6).

In FIG. 2, the size of the first watermark element (5) (W _x 1, W _y 1) is greater than the size (W _x 2, W _y 2) of the second watermark element (6), and the first watermark element (5) and the second watermark element (6) A configuration in which they are arranged at the same pitch in the direction (V1) and the second direction (V2) is shown.

In general, the concave watermark is visually recognized brighter than the base material (2). The amount of transmitted is increased and it is visually recognized brightly. The size of the second watermark element (6) shown in FIG. 2 is smaller than the size of the first watermark element (5), but the depth (H2) of the second watermark element is greater than the depth (H1) of the first watermark element (H1). ), the latent image portion (3) in which the first watermark element (5) of different size and depth is placed and the background portion (3) in which the second watermark element (6) is placed. (4) has the same permeability. In the configuration shown in FIG. 2, the pitch (P _x 1, P y 1) at which the first watermark element (5) is arranged and the pitch (P _x 2, P _y 1) at which the second watermark element (6) is arranged. Although an example in which _y 2) is the same has been described, the pitch (P _x 2, P _y 2) are adjusted appropriately to form the second watermark element (6). In the configuration shown in FIG. , the pitch (P _x 1, P _y 1) for arranging the first watermark element (5) is different from the pitch (P _x 2, P _y 2) for arranging the second watermark element (6). may

In the transmission latent image forming member (1) of the present invention, as shown in FIG. If can be visually confirmed, the pattern of the latent image can be inferred when observed under transmitted light. _x 1, W _y 1) and the size (W _x 2, W _y 2) of the second watermark element (6) are preferably 500 μm or less.

(processing method)
In the present invention, the method of forming the concave first watermark element (5) and the second watermark element (6) can use known watermark forming means. It is possible to form a concave watermark by removing the base material (2) by a method using a dandy roll or a circular mesh having convex portions corresponding to the paper, or by laser processing or engraving on the manufactured paper. can.

(effect)
As shown in FIG. 3A, when the transmission latent image pattern (7A) having the above structure is observed from a position directly facing the substrate (2) under transmitted light, the latent image portion (3) and the background portion are observed. Since the transmittance of (4) is the same, the latent image portion (3) and the background portion (4) have the same brightness as shown in FIG. The entire transmission latent image pattern (7A) is visible brighter than the surrounding substrate (2). In the present invention, observation under transmitted light means that, as shown in FIG. Observation is made under the condition that the light source (9) is positioned on the side opposite to the viewpoint (O) of the observer who sandwiches the substrate (2). Further, in the present invention, that the latent image portion (3) and the background portion (4) have the same transparency means that the first watermark element (5) and the second watermark element (5) formed in the latent image portion (3) (6) The latent image portion (3) is so bright that the latent image portion (3) cannot be visually recognized when the substrate (2) is observed facing the substrate (2) under transmitted light due to the balance of the size, arrangement pitch, and depth. 3) and a background portion (4) are formed.

On the other hand, as shown in FIG. 4(a), when observed from an oblique direction with respect to the substrate (2) under transmitted light, the second watermark element (6) is more visible than the first watermark element (5). Since the size is small and the depth (H2) of the second watermark element (6) is large, it becomes a blind spot of the substrate (2) and the transmitted light cannot be observed. Also, the first watermark element (5) is larger than the second watermark element (6), and the depth (H1) of the first watermark element (5) is shallow. The image portion (3) is visible brighter than the surrounding substrate (2). As a result, as shown in FIG. 4(b), the letter "N" appearing in the latent image portion (3) is visually recognized as a latent image, and authenticity can be determined by confirming this. FIG. 4 shows a state in which the observer's viewpoint (O) is oblique to the base material (2). The latent image can be visually recognized even by tilting and observing. When observing the base material (2) from an oblique direction under transmitted light, the second watermark element (6) serves as a blind spot of the base material (2), and the transmitted light can be observed. In more detail, it means that although the substrate (2) itself on which the second watermark element (6) is formed transmits light, as shown in FIG. The second watermark element (6) itself and the background part (4) composed of the second watermark element (6) cannot be visually recognized. Further, the fact that the first watermark element (5) transmits light means that the amount of light transmitted by the first watermark element (5) is larger than that of the second watermark element (6), which is a blind spot of the base material (2). The visible latent image is visible because the latent image portion (3) is relatively brighter than the background portion (4).

In the transmission latent image forming member (1) of the present invention, the oblique observation direction (observation angle with respect to the substrate) with respect to the substrate (2) for visually recognizing the latent image is the first watermark element (5 ) and the shape of the second watermark element (6). , at which point the latent image is visible, since the light transmitted through the second watermark element (6) is initially not visible. In addition, when the observation direction that is horizontal to the base material (2) is gradually tilted to the observation direction that faces the base material (2), the first watermark element ( Since the transmitted light from 5) is visible first, the latent image of the letter "N" is visible.

In the transmission latent image forming member (1) of the present invention, since the latent image portion (3) and the background portion (4) have the same transmittance, the latent image visible when obliquely observed under transmitted light is visible. Since the pattern is highly concealable, it has a high latent image effect that can be seen when observed at an angle.

Another example in which the latent image portion (3) and the background portion (4) have the same transmittance and the latent image can be visually recognized when the substrate (2) is tilted and observed under transmitted light will be described below.

FIG. 5 shows another example of a configuration in which the first watermark element (5) and the second watermark element (6) have different area ratios and depths. The first watermark elements (5) are arranged without gaps in the exposed area. The depth (H2) of the second watermark element (6) formed in the background portion (6) is deeper than the depth (H1) of the first watermark element (5), as described above. By adjusting the depth (H1, H2) of (5, 6) and the size of the second watermark element (6), the transparency of the latent image portion (3) and the background portion (4) are equal. It's becoming

The transmission latent image forming body (1) having the structure shown in FIG. 5 is tilted under transmitted light because the first watermark elements (5) are formed in the entire region of the letter "N" without gaps. As for the visually recognized latent image, the light transmitted through the entire character "N" can be visually recognized, and there is an effect that the latent image with higher resolution than the configuration shown in FIG. 2 can be visually recognized.

Next, a second configuration in which the latent image portion (3) and the background portion (4) have the same transmittance in the present invention and the latent image can be visually recognized when the substrate (2) is tilted and observed under transmitted light is described. do. FIG. 6(a) is an enlarged view of a region surrounded by a broken line in the region where the transmission latent image pattern (7A) of the transmission latent image forming body (1) shown in FIG. 1 is formed, and FIG. 6(b). 6 is a sectional view taken along line AA' of FIG. 6(a). FIG.

A transmission latent image pattern (7A) shown in FIG. 6 is an example of a configuration in which the first watermark element (5) and the second watermark element (6) are different in size and pitch and have the same depth. As a specific example, the first watermark element (5) and the second watermark element (6) shown in FIG. 6 are circular and have the same depth (H1, H2). 5) The size (W _x 1, W _y 1) is larger than the size (W _x 2, W _y 2) of the second watermark element (6). Therefore, comparing the first watermark element (5) and the second watermark element (6) having the same depth, the larger first watermark element (5) is visually recognized brighter. Therefore, the pitch (P _x 2, P _y 2) forming the small second watermark elements (6) is made smaller than the pitch (P _x 1, P _y 1) forming the first watermark elements (5). By forming the same structure, the permeability is the same.

Also in the transmission latent image forming body (1) having the configuration shown in FIG. is a blind spot, the latent image of the character "N" displayed by the latent image portion (3) can be visually recognized. In the configuration shown in FIG. 6, the first watermark elements (5) are arranged at a constant pitch (P _x 1, P _y 1). They may be randomly arranged in pitch, giving uniform brightness to the latent image portion (3) under transmitted light, as is the second watermark element (6) placed in the background portion (4).

Subsequently, the third configuration of the present invention, in which the latent image portion (3) and the background portion (4) have the same transmittance and the latent image can be visually recognized when the substrate (2) is tilted and observed under transmitted light, will be described. do. FIG. 7(a) is an enlarged view of a region surrounded by a broken line in the region where the transmission latent image pattern (7A) of the transmission latent image forming body (1) shown in FIG. 1 is formed, and FIG. 7(b). 7 is a cross-sectional view taken along line BB' of FIG. 7(a). FIG.

In the transmission latent image pattern (7A) shown in FIG. 7(a), the first watermark element (5) and the second watermark element (6) are composed of lines having the same line width (W1, W2), The direction (V _x 1) in which the first watermark element (5) formed in the latent image area (3) is arranged and the second watermark element (6) formed in the background area (4) are arranged. This is an example of a configuration in which the direction (V _y 1) is different. In the transmission latent image pattern (7A) shown in FIG. 7, the first watermark elements (5) are arranged at a constant pitch (P1) in the first direction (V _x 1), and the second watermark elements ( 6) are arranged at a constant pitch (P2) in the second direction (V _y 1), the pitch (P1) of the first watermark element (5) and the pitch of the second watermark element (6) (P2) are the same. Also, the depth (H1) of the first watermark element (5) and the depth (H2) of the second watermark element (6) are also the same, as shown in the cross-sectional view of FIG. 7(b). . The arrangement of the first watermark element (5) and the second watermark element (6) is not limited to the arrangement shown in FIG. 7 as long as they are arranged in different directions. If the angle difference between the first direction (V _x 1) and the second direction (V _y 1) _is small _, the visibility of the latent image decreases. ) is _preferably 45° _or more, and as shown in FIG. preferable.

In the transmission latent image pattern (7A) shown in FIG. 7, the image line widths (W1, W2), the pitches (P1, P2) and the depths ( H1 and H2) are the same, so the transparency of the latent image portion (3) and the background portion (4) are the same.

Even in the transmission latent image forming body (1) having the structure shown in FIG. 7, the latent image portion (3) is revealed when observed by gradually tilting from the direction directly facing the base material (2) under transmitted light. A latent image of the letter "N" is visible. When observing a latent image on the transmission latent image forming body (1) having the configuration shown in FIG. Observation is made from a direction (BB' line) oblique to the substrate (2). Under the transmitted light shown in FIG. 3(a), the second watermark element (6) is gradually tilted from the viewing point (O) facing the substrate (2) with respect to the substrate (2). Since the image line width (W2) of is shorter than the length of the first watermark element (5), the second watermark element (6) first becomes a blind spot of the substrate (2) to observe the transmitted light. (Specifically, there is no difference in brightness with the surrounding substrate), at which time the amount of light transmitted through the first watermark element (5) is reduced to that of the second watermark element (6 ), the latent image of the letter "N" is visible.

FIG. 7 shows an example in which the first watermark element (5) and the second watermark element (6) are composed of straight lines, but they may be composed of broken lines as shown in FIG. In this case, one first watermark element (5) shown in FIG. 7 is divided at regular intervals, and the first watermark element (5) shown in FIG. The watermark element (5') of 1' is configured such that the size ( _Wy1 ) in the image line direction is larger than the image line width (W1). In addition, the second watermark element (6' ₎ , which constitutes a part of the second watermark element (6) formed by broken lines in FIG. A configuration larger than the width (W2) is used.

FIG. 7 shows the principle by which the latent image can be visually recognized even in the transmission latent image forming member (1) having the structure shown in FIG. It is the same as the transmission latent image forming member (1) composed of the structure, and the substrate (2) is gradually moved from the viewpoint (O) at the position directly facing the substrate (2) under the transmitted light shown in FIG. 3(a). ), the image line width (W2) of the second watermark element (6) is shorter than the size (W _y 1) of the first watermark element (5′) in the image line direction. As a result, first, the second watermark element (6) becomes a blind spot of the substrate (2), making it impossible to observe the transmitted light (more specifically, the difference in brightness from the surrounding substrate is state), then the amount of light transmitted through the first watermark element (5) is greater than the second watermark element (6), and the latent image of the letter "N" is visible.

In FIGS. 7 and 8, an example in which the first watermark element (5) and the second watermark element (6) are composed of an image line and a dashed line has been described. etc. may be used. In addition, when the first watermark element (5) and the second watermark element (6) are composed of image lines, the latent image portion (3) is The area ratio and depth of the first watermark element (5) and the second watermark element (6) formed in the background portion (4) may be different. 7 and 8, the first watermark elements (5) are arranged at a constant pitch (P1), but the first watermark elements (5) are randomly arranged at different pitches. so that the latent image portion (3) is uniformly bright under transmitted light, as is the second watermark element (6) placed in the background portion (4).

(First watermark with watermark ink)
Although the first watermark element (5) formed in the latent image portion (3) described above is an example of a concave configuration, it penetrates into the interior of the base material (2) and is visually recognized brightly. It may be formed by printing some watermark ink. Specific materials include resins, waxes, animal and vegetable oils, etc., and may be printed using commercially available watermark inks. Unlike the second watermark element (6), the first watermark element (5) formed by printing watermark ink was obliquely observed under transmitted light because the substrate (2) did not dent. At that time, the latent image can be visually recognized through light transmission. Even when the first watermark element (5) is formed by printing the watermark ink, the size of each element, The area ratio, the depth (H2) of the second watermark element (6), etc. may be adjusted.

In the first embodiment, the latent image portion (3) has been described as an example in which the character "N" is displayed, but the present invention is not limited to this, and may be other characters, figures, symbols, or the like. good too. In addition, although the example in which the letter "N" can be visually recognized in the latent image that can be viewed by tilting under transmitted light has been described, the configuration may be such that the background of the letter "N" can be viewed. A first watermark element (5) is formed in the area showing the background of , and a second watermark element (6) is formed in the area showing the letter "N". In the first embodiment, the transmission latent image pattern (7A) is an example of a "circle", but it may be other figures, characters, symbols, etc. In that case, the second watermark element The area of the background portion (4) that forms (6) may be changed as appropriate.

(Second embodiment)
In the second embodiment, a pattern different from the latent image is visually recognized when observed from the viewpoint (O) at a position directly facing the substrate (2) under transmitted light, and the observation angle is changed under transmitted light. A transmissive latent image forming body (1) in which a visually recognized pattern changes by changing. The configuration of the transmission latent image forming member (1) of the second embodiment will be described below.

FIG. 9(a) shows a transmission latent image forming body (1) of the second embodiment, and FIG. 9(b) shows a transmission latent image forming body (1) of the second embodiment. 1) is a diagram showing a pattern visually recognized when observed from a viewpoint (O) at a position directly facing the substrate (2) under transmitted light, and FIG. 9(c) is observed under transmitted light. It is a figure which shows the pattern of the latent image visually recognized by changing an angle. In order to explain the second embodiment in an easy-to-understand manner, the pattern represented by the latent image portion (3) and the background portion (4) that constitute the transmission latent image pattern (7A) of the second embodiment is the same as that of the first embodiment. An example of a configuration in which the letter "N" is modeled as in the embodiment will be described. Further, as shown in FIG. 9(b), the design visually recognized when observed from the viewpoint (O) facing the substrate (2) under transmitted light is, for example, a “star” design. An example will be described, and points of the configuration of the transmission latent image forming body (1) of the second embodiment that are different from those of the first embodiment will be described.

FIG. 10 is a diagram showing the structure of the watermark pattern (7) formed on the transmissive latent image forming body (1) of the second embodiment. 10(b) and a transmission pattern (7B) shown in FIG. 10(c). In the second embodiment, the configuration of the transmission latent image pattern (7A) is the same as in the first embodiment, and the latent image portion (3) showing the character "N" and the background thereof. The latent image portion (3) and the background portion (4) have the same transparency.

FIG. 11 is an enlarged view of a region in which the transmission latent image pattern (7A) and the transmission pattern (7B) are formed, surrounded by broken lines in FIG. 10(a). In FIG. 11, the thick dotted line indicates the outline of the "star-shaped" pattern that the transparent pattern (7B) represents. A plurality of third watermark elements (11) are arranged so as not to overlap the element (5) and the second watermark element (6).

FIG. 11 shows an example in which the third watermark element (11) is arranged at a constant pitch (P _x 3, P _y 3), but the first watermark element (5) and the second watermark element (5) The third watermark element (11) does not need to be arranged at a constant pitch as long as it is arranged without overlapping with the element (6) and is arranged according to the design of the desired transparent pattern (7B). good.

In FIG. 11, the third watermark element (11) shows a circular configuration, but a configuration that does not overlap with the first watermark element (5) and the second watermark element (6) is a triangular shape. , a square or the like, or a streak configuration.

The third watermark element (11) of the second embodiment has a concave shape, and known means for forming a watermark can be used. It can be formed by removing the base material (2) by a method using a roll or a cylinder, or by laser processing or engraving on the produced paper.

The size of the third watermark element (11) is the same as or smaller than the size of the second watermark element (6), specifically the third watermark element corresponding to the diameter of the circular shape shown in FIG. The size (W _x 3, W _y 3) of (11) is the same as or smaller than the size (W _x 2, W _y 2) of the second watermark element (6).

Also, the depth (H3) of the third watermark element (11) is the same as or greater than the depth (H2) of the second watermark element (6), specifically as shown in FIG. 12(a). So that the depth (H3) of the third watermark element (11) is the same as the depth (H2) of the second watermark element (6) or, as shown in FIG. The depth (H3) of the watermark element (11) is deeper than the depth (H2) of the second watermark element (6). 12(a) and 12(b) are diagrams showing the depth relationship between the second watermark element (6) and the third watermark element (11). It does not show the positional relationship between the watermark element (6) and the third watermark element (11).

(effect)
When the watermark pattern (7) of the second embodiment having the above configuration is observed from a position directly facing the base material (2) under transmitted light, a transmitted latent image in which the latent image portion (3) is hidden Since the transparent pattern (7B) is formed in addition to the pattern (7A), as shown in FIG. You can see the star pattern.

On the other hand, when the watermark pattern (7) of the second embodiment is observed under transmitted light from an oblique direction with respect to the base material (2), the second watermark element (6) in the background part (4) is the base material. The depth (H3) of the third watermark element (11) is greater than or equal to the depth (H2) of the second watermark element (6) in the same way as the blind spot of the material (2). , the third watermark element (11) also becomes a blind spot of the base material (2) and the transmitted light cannot be observed (in detail, there is no difference in brightness with the surrounding base material). As a result, when observing from an oblique direction with respect to the substrate (2), the character "N" appearing in the latent image portion (3) is visually recognized as a latent image, as shown in FIG. 9(c). In the transmission latent image forming body (1) of the second embodiment, the authenticity is determined by confirming the effect of changing the visually recognized pattern by changing the observation angle under transmitted light. be able to.

In the second embodiment, all the third watermark elements (11) shown in FIG. 11 are formed with the same size, but the size (W If _x 2, W _y 2) or less, the size may be partially changed. The third watermark element (11) shown in FIG. 11 is arranged at a constant pitch (P _x 3, P _y 3). , the pitch (P _x 3, P _y 3) may be different. Also, all the third watermark elements (11) forming the transparent pattern (7B) may be configured with the same depth (H3), or the depth (H2) of the second watermark element (6) With the above configuration, the depth (H3) may be partially varied within the area showing the "star pattern" pattern. According to these configurations, a difference in the amount of transmitted light is generated within the area of the "star" pattern represented by the transparent pattern (7B), and the "star" pattern with a contrast difference can be visually recognized. That is, gradation can be expressed in a watermark that can be visually recognized when observed from a position directly facing the substrate (2) under transmitted light.

Further, in the second embodiment, the area forming the "star" pattern which is the transmission pattern (7B) is the latent image portion (3) and the background portion (4) of the transmission latent image pattern (7A). Although an example has been described in which the third watermark element (11) is arranged to overlap a part of the constituent area, the third watermark element (11) is arranged so as not to overlap the first watermark element (5) and the second watermark element (6). The transmission pattern (7B) may be arranged so as to overlap only a part of the area constituting the latent image part (3), or only part of the area constituting the background part (4). may be placed in duplicate.

(Third Embodiment)
The third embodiment is a transmissive latent image forming body (1) in which the pattern of a latent image to be viewed changes by changing the viewing angle by tilting under transmitted light. The configuration of the transmission latent image forming member (1) of the third embodiment will be described below.

FIG. 13(a) is a view showing a transmission latent image forming member (1) of the third embodiment, and a latent image portion (3) forming a watermark pattern (7) of the third embodiment. is a latent image that can be visually recognized when the angle of observation is changed by tilting under transmitted light. It has a configuration including the "square" pattern shown in FIG. 13(d).

14A and 14B are diagrams showing the configuration of the latent image portion (3) according to the third embodiment. The latent image portion (3) shown in FIG. 14A is the "circular" shape shown in FIG. (hereinafter referred to as "first latent image portion (3-1)"), the first latent image portion from the area corresponding to the "star" pattern shown in FIG. The first latent image from the area excluding (3-1) (hereinafter referred to as "second latent image portion (3-2)") and the area corresponding to the "square" pattern shown in FIG. It consists of an area (hereinafter referred to as “third latent image portion (3-3)”) excluding the portion (3-1) and the second latent image portion (3-2).

The first latent image portion (3-1), the second latent image portion (3-2) and the third latent image portion (3-3) are provided with concave first watermark elements (5). Although formed, the first watermark elements (5) formed in each latent image portion (3-1, 3-2, 3-3) differ in size and depth and will be described in detail.

FIG. 15(a) is a partially enlarged view of the first latent image portion (3-1), and the first latent image portion (3-1) is shown in the enlarged view of FIG. 15(a). , a plurality of first watermark elements (5) are arranged. Hereinafter, the first watermark element (5) arranged in the first latent image portion (3-1) will be described as "1-1 watermark element (5-1)". FIG. 15(b) is a cross-sectional view taken along the line AA' of the enlarged view of FIG. 15(a). (5-1) is formed, and the code (H1-1) indicates the depth of the 1-1st watermark element (5-1).

FIG. 16(a) is a partially enlarged view of the second latent image portion (3-2), and the second latent image portion (3-2) is shown in the enlarged view of FIG. 16(a). , a plurality of first watermark elements (5) are arranged. Hereinafter, the first watermark element (5) arranged in the second latent image portion (3-2) will be described as "the 1-2 watermark element (5-2)". FIG. 16(b) is a cross-sectional view taken along the line AA' of the enlarged view of FIG. 16(a), and the second latent image portion (3-2) is the concave 1-2 watermark element. (5-2) is formed, and the code (H1-2) indicates the depth of the 1-2nd watermark element (5-2).

FIG. 17(a) is a partially enlarged view of the third latent image portion (3-3), and the third latent image portion (3-3) is shown in the enlarged view of FIG. 17(a). , a plurality of first watermark elements (5) are arranged. Hereinafter, the first watermark element (5) arranged in the third latent image portion (3-3) will be described as "the 1-3 watermark element (5-3)". FIG. 17(b) is a cross-sectional view taken along the line AA' of the enlarged view of FIG. 17(a), and the third latent image portion (3-3) is the concave 1-3 watermark element. (5-3) is formed, and the code (H1-3) indicates the depth of the 1-3rd watermark element (5-3).

The 1-1st watermark element (5-1) to the 1-3rd watermark element (5-3) shown in FIGS. 15 to 17 have different sizes and depths, but the first latent image portion ( 3-1), the second latent image portion (3-2) and the third latent image portion (3-3) have the same transmittance. Specifically, as shown in FIGS. 15 to 17, the size of the watermark element (5) is such that the 1-1 watermark element (5-1) is large and the 1-2 watermark element (5-2) , 1st to 3rd watermark elements (5-3). Also, as shown in FIGS. 15 to 17, the depth of the watermark element (5) is as follows: the 1-1 watermark element (5-1) is shallow, the 1-2 watermark element (5-2) Deeper in order of 1-3 watermark elements (5-3). As described in paragraphs (0029) and (0031), by adjusting the size and depth of the concave watermark, the transparency can be made equal. Three different watermark elements (5-1, 5-2, 5-3) are configured to have the same transparency. Of the three watermark elements (5) described in the third embodiment, the depth (H1-3 ) is shallower than the depth (H2) of the second watermark element (6) formed in the background portion (4), and the first to third watermark elements ( 5-3) is configured to be larger than the size of the second watermark element (6).

(effect)
Observation of the transmission latent image forming member (1) of the third embodiment configured as described above from a position directly facing the substrate (2) under transmitted light reveals the first latent image portion (3- 1) Since the second latent image portion (3-2) and the third latent image portion (1-3) have the same transmittance, the latent image portion (3) as a whole has uniform brightness. visible. As described above, the latent image portion (3) and the background portion (4) also have the same amount of transmitted light per unit area, so the entire watermark pattern (7) is visually recognized with uniform brightness. .

On the other hand, when observing the base material (2) from a position facing the base material (2) at a gradual tilt, first, since the depth (H2) of the second watermark element (6) formed in the background part (4) is deep, the base material (2) is oblique. This becomes a blind spot of the material (2), making it impossible to observe the transmitted light (more specifically, there is no difference in brightness with the surrounding base material). On the other hand, the 1-1 watermark element (5-1), the 1-2 watermark element (5-2) and the 1-3 watermark element (5-3) are the second watermark element Since it is larger and shallower than (6), light is transmitted. As a result, the first latent image portion (3-1), the second latent image portion (3-2) and the third latent image portion (3-3) transmit light, and each latent image portion ( 3-1, 3-2, and 3-3), the "square" latent image shown in FIG. 13(d) can be seen.

Further, when obliquely observed with respect to the substrate (2), the deepest 1-3 watermark element (5-3) in the latent image portion (3) is the substrate ( It becomes the blind spot of 2) and it becomes impossible to observe the transmitted light. As a result, the third latent image portion (3-3) becomes invisible, and the first latent image portion (3-1) and the second latent image portion (3-2) appear in FIG. A "star-shaped" latent image shown in c) is visible.

Further, when obliquely observed with respect to the substrate (2), the 1-2 watermark element (5-2) having the second deepest depth among the latent image portions (3) is the basis. This becomes a blind spot of the material (2), making it impossible to observe the transmitted light. As a result, the second latent image portion (3-2) also becomes invisible, and the "circular" latent image shown in FIG. can do. As described above, in the transmission latent image forming body (1) of the third embodiment, when the viewing angle is changed by tilting under transmitted light, the pattern of the latent image that is visually recognized changes. can be used for authenticity determination.

In the third embodiment, the pattern shown in FIG. 13 has been described as an example of the latent image that can be visually recognized when the viewing angle is changed by tilting under transmitted light. , but not limited to. Further, each latent image portion (3-1, 3-2, 3-3) shown in FIG. 14 is an example in which the inner pattern is surrounded by the outer pattern. , the latent image portions may be arranged adjacent to each other or, as shown in FIG. 18B, the latent image portions may be arranged apart from each other. 2), the design of the latent image portion (3) is not visible when observed from a position directly facing the background portion (4). should be surrounded by In FIG. 18B, the "star" pattern is the first latent image portion (3-1), the "square" pattern is the second latent image portion (3-2), and the "triangle" pattern is the second latent image portion (3-2). In this example, the pattern is represented by the third latent image portion (3-3), but each latent image portion that represents each pattern may be changed as shown in FIG. 18(c). In addition, in the third embodiment, an example was described in which the number of latent images that can be visually recognized when the viewing angle is changed by tilting under transmitted light is three. OK, or two.

Examples of the transmissive latent image forming member (1) specifically produced according to the above-described mode for carrying out the invention will be described below in detail, but the present invention is not limited to these examples. do not have.

(Example)
An example is a transmission latent image forming member (1) in which a watermark pattern (7) having a transmission latent image pattern (7A) shown in FIG. 5 is formed on a substrate (2). A detailed configuration will be described.

As the base material (2) of the example, a white paper base material having a thickness of 100 μm was produced using cotton pulp as a raw material and using a hand sheet making machine (manufactured by Kumagai Riki Kogyo Co., Ltd.). At this time, a concave watermark forming a transmission latent image pattern (7A) described below was formed by providing a convex portion on the wire mesh of the hand sheet making machine.

In the latent image portion (3) forming the transmission latent image pattern (7A), the first watermark elements (5) were arranged without gaps to form the letter "N". The depth (H1) of the first watermark element (5) was set to 30 μm.

Further, the background portion (4) constituting the transmission latent image pattern (7A) has the size (W _x 2, W _y 2) of the second watermark element (6) set to 250 μm, and the second watermark element (6 ) with a pitch (P _x 2, P _y 2) of 375 μm. The depth (H2) of the second watermark element (6) was set to 62 μm.

The latent image portion (3) and the background portion (4) of the transmission latent image forming body (1) prepared as an example have different configurations of the first watermark element (5) and the second watermark element (6). However, they had the same transmittance, and were visually recognized with the same brightness when observed from a position directly facing the substrate (2) under transmitted light. In addition, when observed from an oblique direction with respect to the base material (2) under transmitted light, the second watermark element (6) becomes a blind spot of the base material (2), and the light is transmitted and relatively The pattern of the bright latent image portion (3) could be visually recognized as a latent image.

1 Transmission latent image pattern forming member 2 Base material 3 Latent image portion 3-1 First latent image portion (Third Embodiment)
3-2 Second latent image portion (third embodiment)
3-3 Third latent image portion (third embodiment)
4 Background part 5 First watermark element 5'First' watermark element 6 Second watermark element 6'Second' watermark element 7 Watermark pattern 7B Transparent pattern 9 Light source 11 Third watermark element

Claims (4)

A watermark pattern is formed on at least a part of a base material, and the watermark pattern includes a latent image portion in which a plurality of concave first watermark elements having higher transparency than the base material is formed; and a transmission latent image pattern consisting of a background portion in which a plurality of second watermark elements having a concave shape with high transparency are formed. The background portion has the same transmittance, and the latent image portion and the background portion have the same transmittance,
i) the area ratio of the first watermark element formed in the latent image portion is higher than the area ratio of the second watermark element formed in the background portion, and the depth of the second watermark element is is deeper than the depth of the first watermark element, or
ii) the depth of said second watermark element is the same as the depth of said first watermark element, and the size and pitch of said first watermark element are greater than said second watermark element; or
iii) The first watermark element and the second watermark element are image lines having the same area ratio and depth, and the first watermark element formed in the latent image portion and the background portion are formed. a configuration in which the directions in which the formed second watermark elements are arranged are different;
When the substrate is tilted and observed under transmitted light, at least a part of the second watermark element formed in the background portion becomes a blind spot, and the difference in the amount of transmitted light between the latent image portion and the background portion causes a latent image. A transmissive latent image-forming member characterized in that an image is visible. The latent image portion and the background portion have the configuration of i), and the latent image portion includes the first watermark elements having different sizes and depths, and the first watermark elements having the same transparency. consists of a latent image portion, a second latent image portion, .
The element having the largest size of the first watermark element is the first latent image portion, the element having the smallest size of the first watermark element is the nth latent image portion, and the first latent image portion is the nth latent image portion. the size of the first watermark element decreases in the order of the image portion, the second latent image portion, . . . , the n-th latent image portion;
The shallowest element of the first watermark element is defined as the first latent image portion, the deepest element of the first watermark element is defined as the n-th latent image portion, and the first latent image portion is defined as the n-th latent image portion. the depth of the first watermark element becomes deeper in the order of the image portion, the second latent image portion, . . . , the n-th latent image portion;
2. The transmission latent image forming member according to claim 1, wherein the design of said latent image changes and is visually recognized depending on the angle at which said substrate is tilted and observed under said transmitted light. a latent image portion in which a watermark pattern is formed on at least a part of a base material, the watermark pattern is formed of a watermark ink and includes a plurality of first watermark elements having higher transparency than the base material; A transmission latent image pattern composed of a background portion in which a plurality of second watermark elements having a concave shape with higher transparency than the substrate is formed, and when observed from a position directly facing the substrate under transmitted light, the latent image When the substrate is tilted and observed under transmitted light, at least a part of the second watermark element formed in the background portion becomes a blind spot, and the latent image portion and the background portion have the same transmittance. A transmissive latent image forming member, wherein the latent image is visible due to the difference in the amount of transmitted light in the background portion. The watermark pattern has a concave shape with higher transparency than the base material at a position not overlapping the first watermark element formed in the latent image area and the second watermark element formed in the background area. Further comprising a transmission pattern formed by forming a plurality of third watermark elements, wherein the size of the third watermark element is equal to or smaller than the size of the second watermark element, and the depth of the third watermark element is greater than or equal to the depth of the second watermark element, and
4. The transmission latent image according to any one of claims 1 to 3, wherein the transmission pattern and the latent image change and are visually recognized depending on the angle at which the substrate is observed under the transmitted light. image forming body.

Images