JP7622355B2 - Display body - Google Patents

Description

The present invention relates to a display.

Conventionally, displays capable of displaying three-dimensional images by holograms have been used in products and other articles to prove that the products are genuine (see Patent Documents 1 and 2). Also, instead of holograms, diffraction gratings may be used to display three-dimensional images (see Patent Documents 3 and 4). Displays that display three-dimensional images by holograms or diffraction gratings are difficult to counterfeit or copy.

JP 2001-109362 A JP 2010-139673 A Japanese Patent Application Publication No. 6-281804 Japanese Unexamined Patent Publication No. 7-104211

A three-dimensional image displayed by a hologram or diffraction grating may not give a strong sense of depth to the viewer.
An object of the present invention is to provide a display capable of displaying a three-dimensional image that gives a viewer a strong stereoscopic effect.

According to one aspect of the present invention, there is provided a display device that displays a three-dimensional image including an image of a first object and an image of a second object as a diffraction image, wherein when a three-dimensional object is three-dimensionally restored from the three-dimensional image, a first three-dimensional object corresponding to the first object is restored to a position in front of a display surface of the display device as seen by an observer observing the display device, and is restored to a position away from the display surface, and a second three-dimensional object corresponding to the second object is restored to a position behind the display surface as seen by the observer, and is restored to a position away from the display surface, and no other three-dimensional object is restored between the first three-dimensional object and the second three-dimensional object, wherein the three-dimensional image is an image displayed by a diffraction grating, and the display device comprises a relief layer having a relief structure as the diffraction grating on one main surface that displays the three-dimensional image, and a reflective layer at least partially covering an area of the main surface where the relief structure is provided, and the display surface is the surface of the reflective layer or the interface between the relief structure and the reflective layer .

Here, the term "three-dimensional image" refers to an image that gives the observer a sense of depth due to binocular parallax or motion parallax. Also, the term "diffraction image" refers to an image displayed by a hologram or a diffraction grating.

As described above, with this display, the first three-dimensional object is restored to a position in front of the display surface of the display, and the second three-dimensional object is restored to a position behind the display surface. Therefore, for example, when the display is rotated slightly clockwise or counterclockwise around a specific axis while keeping the lighting conditions constant, the image of the first object moves to the right or left, and the image of the second object moves in the opposite direction to the image of the first object. Therefore, one of the image of the first object and the image of the second object highlights the movement of the other.

As described above, the first three-dimensional object is restored to a position in front of the display surface and separated from the display surface. On the other hand, the second three-dimensional object is restored to a position behind the display surface and separated from the display surface. No other three-dimensional object (third three-dimensional object) is restored between the first and second three-dimensional objects. In other words, the first and second three-dimensional objects are discontinuous. With this configuration, the above-mentioned effects are not impaired, as will be explained below.

When a third three-dimensional object is restored between the first and second three-dimensional objects, the observer may perceive the relative movement of the image of the first or second object that accompanies the rotation of the display body based on the position of the image of the third object corresponding to the third three-dimensional object. Since the third three-dimensional object is located between the first and second three-dimensional objects, the third object is also located between the first and second objects. Therefore, when another three-dimensional object is restored between the first and second three-dimensional objects, the observer may perceive the amount of relative movement of the image of the first or second object that accompanies the rotation of the display body as being smaller than when no other three-dimensional object is restored between the first and second three-dimensional objects.

In the above display, a third three-dimensional object is not restored between the first and second three-dimensional objects. Therefore, the effect of one of the images of the first object and the second object emphasizing the movement of the other is not impaired by the image of the third object corresponding to the third three-dimensional object. Therefore, this display is capable of displaying a three-dimensional image that gives the viewer a strong sense of depth.

It should be noted that the same effect as that described above with reference to the example of stereoscopic vision due to motion parallax can also be obtained in the case of stereoscopic vision due to binocular parallax.
Moreover, a display member that employs a configuration in which a three-dimensional structure is displayed using a relief structure can be manufactured with high productivity.

According to another aspect of the present invention, there is provided a display relating to the above aspect, in which, when the display is observed from the front, the image of the first object and the image of the second object at least partially overlap.
With this configuration, the viewer can particularly easily perceive the relative movement of the image of the first object or the second object that accompanies the rotation of the display body.

According to yet another aspect of the present invention, there is provided a display device relating to any of the above aspects, wherein the distance from the display surface to the first three-dimensional object and the distance from the display surface to the second three-dimensional object are each 0.5 mm or more.
By increasing these distances, the viewer can more easily perceive the relative movement of the image of the first object or the second object caused by the rotation of the display body.These distances are preferably 1 mm or more.

According to yet another aspect of the present invention, there is provided a display according to any of the above aspects, in which the first three-dimensional object and the second three-dimensional object are each located entirely within a distance of 4 mm or less from the display surface.

Increasing this distance typically results in a darker image of the first or second object. It is preferable that this distance be 3 mm or less.

According to yet another aspect of the present invention, there is provided a display body relating to any of the above aspects, in which a distance from the display surface to a position on the surface of the first three-dimensional object away from the display surface is equal to a distance from the display surface to a position on the surface of the second three-dimensional object away from the display surface.
This configuration is suitable for making the brightness of the image of the first object and the brightness of the image of the second object approximately equal.

Alternatively, according to yet another aspect of the present invention, there is provided a display body relating to any of the above aspects, wherein a distance from the display surface to a position on the surface of the first three-dimensional object that is distant from the display surface is shorter than a distance from the display surface to a position on the surface of the second three-dimensional object that is distant from the display surface.
This configuration is suitable when the image of the first object is displayed brighter than the image of the second object.

According to yet another aspect of the present invention, there is provided a display body relating to any of the above aspects, further comprising a printing layer facing the display surface, the printing layer producing a plurality of protrusions on the surface of the display body.
A display employing this configuration is capable of displaying three-dimensional images, and also allows the viewer to feel a special tactile sensation due to the protrusions that the printing layer creates on the surface of the display.

According to yet another aspect of the present invention, there is provided the indicator according to the above aspect, wherein the height of the plurality of protrusions is within a range of 5 to 40 μm.
If the height of the protrusions is small, it becomes difficult for a viewer to sense the presence of these protrusions by touch when he or she touches the surface of the display, whereas if the height of the protrusions is excessively large, blocking is likely to occur.

According to yet another aspect of the present invention, there is provided the display device according to any one of the above aspects, wherein the plurality of protrusions include a plurality of line patterns spaced apart from each other and arranged in the width direction.
When a viewer touches the surface of a display body adopting this configuration, the viewer can easily perceive the presence of the convex portion by touch. This configuration is also suitable for making the part of the three-dimensional image that is hidden by the line pattern visible by slightly rotating the display body around an axis that is approximately parallel to the length direction of the line pattern. For example, when a display body with a distance from the display surface to the first three-dimensional object of 1 mm is observed from the front (when observed at an observation angle of 0°) and when observed at an observation angle of 10°, the position of the image of the first object changes by about 0.17 mm. Therefore, if the width of the line pattern is sufficiently small, the part of the three-dimensional image that is hidden by the line pattern becomes visible.

According to yet another aspect of the present invention, there is provided a display device according to the above aspect, wherein the width of each of the plurality of line patterns is within a range of 0.02 to 0.1 mm, and the plurality of line patterns are arranged at a pitch within a range of 0.2 to 0.5 mm.
According to this configuration, adjacent line patterns are unlikely to be connected. In addition, when a viewer touches the surface of a display body employing this configuration, the viewer can easily sense the presence of the convex portions by touch. Furthermore, this configuration is suitable for making a portion of a three-dimensional image that is hidden by a line pattern visible by slightly rotating the display body around an axis that is approximately parallel to the length direction of the line pattern.

According to yet another aspect of the present invention, there is provided a transfer foil comprising a transfer material layer including a display body according to any of the above aspects, and a support that supports the transfer material layer in a peelable manner.

According to yet another aspect of the present invention, there is provided an adhesive label comprising a display body according to any of the above aspects and an adhesive layer provided on the display body.

According to yet another aspect of the present invention, there is provided an article with a display body, comprising a display body according to any of the above aspects and an article supporting the display body.

FIG. 1 is a plan view showing a display according to an embodiment of the present invention. 2 is a cross-sectional view taken along line II-II of the display shown in FIG. 1. 3 is a diagram showing an example of a positional relationship in a virtual space between the display body of FIGS. 1 and 2, first and second three-dimensional objects obtained by three-dimensional reconstruction from the three-dimensional images displayed by the display body, and an observer. FIG. 4 is a diagram showing an image displayed on the display unit shown in FIGS. 1 to 3 when observed from substantially the front. FIG. 4 is a diagram showing an image displayed on the display shown in FIGS. 1 to 3 when observed obliquely from the right. FIG. 4 is a diagram showing an image displayed on the display shown in FIGS. 1 to 3 when observed obliquely from the left. FIG. 13 is a diagram showing an example of the positional relationship in a virtual space between a display body according to a first comparative example, first and second three-dimensional objects obtained by three-dimensional reconstruction from a three-dimensional image displayed by it, and an observer. FIG. 8 is a diagram showing an image displayed on the display shown in FIG. 7 when observed from substantially the front. 8 is a diagram showing an image displayed on the display shown in FIG. 7 when observed obliquely from the right. 8 is a diagram showing an image displayed on the display shown in FIG. 7 when observed obliquely from the left. 13 is a diagram showing an example of the positional relationship in a virtual space between a display body according to a second comparative example, first and second three-dimensional objects obtained by three-dimensional reconstruction from a three-dimensional image displayed by the display body, and an observer. FIG. 12 is a diagram showing an image displayed on the display shown in FIG. 11 when observed from substantially the front. 12 is a diagram showing an image displayed on the display shown in FIG. 11 when observed obliquely from the right. 12 is a diagram showing an image displayed on the display shown in FIG. 11 when observed obliquely from the left. 3 is a diagram showing an example of the positional relationship in virtual space between the display bodies of FIGS. 1 and 2 and first and second three-dimensional objects obtained by three-dimensional reconstruction from the three-dimensional images displayed thereby; FIG. FIG. 11 is a cross-sectional view of a display according to a modified example. 17 is a diagram showing an image displayed by the display device in FIG. 16 under certain conditions. 17A and 17B are diagrams showing images displayed by the display device in FIG. 16 under other conditions. FIG. 3 is a cross-sectional view showing an example of a transfer foil. FIG. 2 is a cross-sectional view showing an example of an adhesive label. FIG. 1 is a plan view showing an example of an article with a display member.

The following describes an embodiment of the present invention with reference to the drawings. The embodiment described below is a more specific embodiment of one of the above aspects. Elements having the same or similar functions are given the same reference numerals, and duplicate descriptions are omitted.

<Display body>
Fig. 1 is a plan view showing a display according to an embodiment of the present invention, Fig. 2 is a cross-sectional view taken along line II-II of the display shown in Fig. 1.

In the figure, the X direction and the Y direction are parallel to the main surface of the display body 10 and are perpendicular to each other. The Z direction is perpendicular to the X direction and the Y direction. In other words, the Z direction is the thickness direction of the display body 10.

A display 10 shown in FIGS. 1 and 2 includes a relief layer 11, a reflective layer 12, and a protective layer 13.
The relief layer 11 is made of a material having optical transparency, for example, a colorless and transparent material. A relief structure RS that displays a three-dimensional image as a diffraction image is provided on the main surface of the relief layer 11 on the side of the reflective layer 12. Here, the relief structure RS is provided only in a partial region of the main surface. Of the main surface of the relief layer 11, the region where the relief structure RS is provided is a first region R1, a part of the region where the relief structure RS is not provided is a second region R2, and the remaining region is a third region.

Here, the first region R1 has an elliptical shape extending in the X direction. The second region R2 surrounds the first region R1. The third region extends along an edge of the relief layer 11 parallel to the Y direction. The main surface of the relief layer 11 does not have to include at least one of the second region R2 and the third region.

The relief structure RS may be a surface relief hologram or a diffraction grating. In the former case, the relief structure RS may have the structure described in, for example, WO 2017/209113. In the latter case, the relief structure RS may have the structure described in, for example, JP 6-281804 A or JP 7-104211 A.

The relief structure RS displays a three-dimensional image as a diffractive image, as described above. The relief structure RS may be designed to display a monochromatic image or a multi-chromatic image. The three-dimensional image displayed by the relief structure RS will be described in more detail below.

The reflective layer 12 covers the first region R1 and the second region R2. The reflective layer 12 is a patterned metal layer. The portion of the reflective layer 12 that covers the relief structure RS has a conformal shape with respect to the relief structure.

The protective layer 13 covers the reflective layer 12 and has the same shape as the reflective layer 12. The protective layer 13 is a layer that is used as an etching mask when patterning the metal layer into the reflective layer 12. The protective layer 13 can be omitted.

As described below, this display 10 is capable of displaying three-dimensional images that give the viewer a strong sense of depth.

Figure 3 is a diagram showing an example of the positional relationship in virtual space between the display of Figures 1 and 2, the first and second three-dimensional objects obtained by three-dimensional reconstruction from the three-dimensional images displayed by them, and an observer. Figure 4 is a diagram showing an image displayed by the display shown in Figures 1 to 3 when observed from approximately the front. Figure 5 is a diagram showing an image displayed by the display shown in Figures 1 to 3 when observed from diagonally right. Figure 6 is a diagram showing an image displayed by the display shown in Figures 1 to 3 when observed from diagonally left.

The relief structure RS of the display body 10 shown in Figures 1 and 2 is designed so that, when a three-dimensional object is three-dimensionally restored from the three-dimensional image it displays, a first three-dimensional object TOD1 and a second three-dimensional object TOD2 are restored, as shown in Figure 3. Furthermore, this relief structure RS is designed so that, when a three-dimensional object is three-dimensionally restored from the three-dimensional image it displays, no other three-dimensional object is restored between the first three-dimensional object TOD1 and the second three-dimensional object TOD2, as shown in Figure 3.

Here, the first three-dimensional object TOD1 has a star shape with a thicker center than the periphery, and its thickness direction is parallel to the Z direction. Here, the second three-dimensional object TOD2 has a disk shape, and its thickness direction is parallel to the Z direction.

The first three-dimensional object TOD1 is restored to a position in front of the display surface of the display body 10 as viewed by the observers OB1 to OB3 who are viewing the display body 10, and is moved away from the display surface. The second three-dimensional object TOD2 is restored to a position behind the display body 10 as viewed by the observers OB1 to OB3, and is moved away from the display surface. Here, the display surface of the display body 10 is a plane that is perpendicular to the thickness direction of the display body 10 and where the interface between the relief layer 11 and the reflective layer 12 is located.

Here, the first three-dimensional object TOD1 and the second three-dimensional object TOD2 are at the same position when viewed from the Z direction. Note that in reality, the portion of the first three-dimensional object TOD1 that does not face any of the observers OB1 to OB3 is not three-dimensionally restored. Furthermore, the portion of the second three-dimensional object TOD2 that is blocked by the first three-dimensional object TOD1 and cannot be seen by any of the observers OB1 to OB3 is also not three-dimensionally restored. To make it easier to understand, in Figure 3, these objects are depicted as if such portions were three-dimensionally restored.

The three-dimensional reconstruction of a solid object from a three-dimensional image is performed by the following method.
That is, first, a plurality of images displayed by the display 10 are captured at different observation angles, and feature points are matched between the images. ORB, SIFT, or FLANN can be used for matching feature points between the images.

The position of each feature point in virtual space can be determined using the principles of triangulation. This can then be used to reconstruct a three-dimensional object in virtual space.

When using the principle of triangulation to reconstruct a three-dimensional object from three or more images, the same feature point may appear at multiple positions in virtual space. In this case, the center of gravity of these positions is taken as the position of that feature point in virtual space. In this case, if the same feature point appears at multiple positions in virtual space and one of the positions is significantly deviated from the other two or more positions, the former can be excluded to calculate the center of gravity.

Next, the display body 10 is reproduced in the virtual space in which the three-dimensional object has been restored. Specifically, the display body 10 is reproduced in the virtual space so that the image that an observer reproduced in the virtual space perceives when looking at the three-dimensional object overlaps with the image displayed by the display body 10 toward the observer.
By restoring the first three-dimensional object TOD1 and the second three-dimensional object TOD2 in the virtual space and reproducing the display body 10 and the observer OB1 in the manner described above, they can be used to explain the image displayed by the display body 10 as follows.

When the surface of the display body 10 facing the relief layer 11 is illuminated with white light from a direction perpendicular to the X direction and inclined to the Y direction, and observed from approximately the front, that is, from the position of the observer OB1, the display body 10 displays an image I1 of a first object and an image I2 of a second object, as shown in FIG. 4. Here, the first object and the second object correspond to the first three-dimensional object TOD1 and the second three-dimensional object TOD2 described above, respectively. That is, here, the first object has a star shape whose center is thicker than the periphery, and the second object has a disk shape. Under the above observation conditions, the display body 10 displays the images I1 and I2 so that they each face approximately the front, the first object is located in front of the second object, and their centers are aligned.

Under similar lighting conditions, when the surface of the display 10 facing the relief layer 11 is observed diagonally from the right, i.e., when observed from the position of observer OB2, the display 10 displays an image I1 of the first object and an image I2 of the second object as shown in FIG. 5. That is, the display 10 displays image I1 as if the first object faces diagonally left as seen by the observer and has moved slightly to the left from the state shown in FIG. 4. The display 10 also displays image I2 as if the second object faces diagonally left as seen by the observer and has moved slightly to the right from the state shown in FIG. 4.

When the surface of the display body 10 facing the relief layer 11 is observed diagonally from the left under similar lighting conditions, that is, when observed from the position of the observer OB3, the display body 10 displays the image I1 of the first object and the image I2 of the second object as shown in FIG. 6. That is, the display body 10 displays the image I1 as if the first object faces diagonally to the right as seen by the observer and has moved slightly to the right from the state shown in FIG. 4. The display body 10 also displays the image I2 as if the second object faces diagonally to the right as seen by the observer and has moved slightly to the left from the state shown in FIG. 4.

In this way, the display 10 is configured so that the orientation and position of the first and second objects in the image it displays changes continuously in response to changes in the observation angle. Therefore, the image displayed by the display 10 appears three-dimensional due to binocular parallax and/or motion parallax.

Figure 7 is a diagram showing an example of the positional relationship in virtual space between a display according to a first comparative example, first and second three-dimensional objects obtained by three-dimensional reconstruction from the three-dimensional image displayed by the display, and an observer. Figure 8 is a diagram showing an image displayed by the display shown in Figure 7 when observed from approximately the front. Figure 9 is a diagram showing an image displayed by the display shown in Figure 7 when observed from diagonally to the right. Figure 10 is a diagram showing an image displayed by the display shown in Figure 7 when observed from diagonally to the left.

The display body 10 in FIG. 7 is similar to the display body 10 described with reference to FIG. 1 to FIG. 6, except for the following design. That is, in the display body 10 in FIG. 7, the first three-dimensional object TOD1 is located in front of the display surface of the display body 10 as seen by the observers OB1 to OB3 who are observing the display body 10, but is restored to be in contact with the display surface. Also, the second three-dimensional object TOD2 is located behind the display body 10 as seen by the observers OB1 to OB3, but is restored to be in contact with the display surface.

When the surface of the display 10 in FIG. 7 facing the relief layer 11 is illuminated with white light from a direction perpendicular to the X direction and tilted with respect to the Y direction, and observed from approximately the front, i.e., when observed from the position of an observer OB1, the display 10 displays an image I1 of a first object and an image I2 of a second object, as shown in FIG. 8. In other words, the image displayed by the display 10 in FIG. 7 under these conditions is substantially the same as the image described with reference to FIG. 4.

Under similar lighting conditions, when the surface of the relief layer 11 side of the display 10 shown in FIG. 7 is observed diagonally from the right, that is, when observed from the position of the observer OB2, the display 10 displays an image I1 of a first object and an image I2 of a second object as shown in FIG. 9. That is, the display 10 displays image I1 as if the first object were facing diagonally left as seen by the observer, with almost no change in position. Also, the display 10 displays image I2 as if the second object were facing diagonally left as seen by the observer, with almost no change in position.

Furthermore, under similar lighting conditions, when the surface of the relief layer 11 side of the display 10 shown in FIG. 7 is observed diagonally from the left, that is, when observed from the position of the observer OB3, the display 10 displays an image I1 of a first object and an image I2 of a second object as shown in FIG. 10. That is, the display 10 displays image I1 as if the first object were facing diagonally to the right as seen by the observer, with almost no change in position. The display 10 also displays image I2 as if the second object were facing diagonally to the right as seen by the observer, with almost no change in position.

In this way, the display 10 shown in FIG. 7 is also configured so that the orientations of the first and second objects in the image it displays change continuously in response to changes in the observation angle. Therefore, the image displayed by the display 10 appears three-dimensional due to binocular parallax and/or motion parallax. However, even if the observation angle is changed in the display 10 shown in FIG. 7, the first and second objects in the image it displays hardly move in opposite directions. Therefore, the three-dimensional image displayed by the display 10 shown in FIG. 7 does not give the viewer as strong a sense of three-dimensionality as the three-dimensional image displayed by the display 10 described with reference to FIGS. 1 to 6.

Fig. 11 is a diagram showing an example of the positional relationship in virtual space between a display according to a second comparative example, first and second three-dimensional objects obtained by three-dimensional reconstruction from the three-dimensional image displayed by the display, and an observer. Fig. 12 is a diagram showing an image displayed by the display shown in Fig. 11 when observed from approximately the front. Fig. 13 is a diagram showing an image displayed by the display shown in Fig. 11 when observed from diagonally to the right. Fig. 14 is a diagram showing an image displayed by the display shown in Fig. 11 when observed from diagonally to the left.

The display body 10 of FIG. 11 is similar to the display body 10 described with reference to FIG. 1 to FIG. 6, except for the following design. That is, in the display body 10 of FIG. 11, the second three-dimensional object TOD2 is restored to have a larger dimension in the Z direction compared to the display body 10 described with reference to FIG. 1 to FIG. 6. Specifically, in the display body 10 of FIG. 11, a part of the second three-dimensional object TOD2 is located behind the display body 10 as viewed by the observers OB1 to OB3, but the remaining part is restored to be in contact with the first three-dimensional object TOD1 at a position in front of the display body 10 as viewed by the observers OB1 to OB3.

When the surface of the display 10 in FIG. 11 facing the relief layer 11 is illuminated with white light from a direction perpendicular to the X direction and tilted with respect to the Y direction, and observed from approximately the front, that is, when observed from the position of an observer OB1, the display 10 displays an image I1 of a first object and an image I2 of a second object, as shown in FIG. 12. That is, the image displayed by the display 10 in FIG. 11 under these conditions is substantially the same as the image described with reference to FIG. 4.

Under similar lighting conditions, when the surface of the relief layer 11 side of the display 10 shown in FIG. 11 is observed diagonally from the right, that is, when observed from the position of the observer OB2, the display 10 displays an image I1 of a first object and an image I2 of a second object as shown in FIG. 13. That is, the display 10 displays image I1 as if the first object faces diagonally left as seen by the observer, and has moved slightly to the left from the state shown in FIG. 12. The display 10 also displays image I2 as if the second object faces diagonally left as seen by the observer, with almost no change in position.

When the surface of the relief layer 11 side of the display 10 shown in FIG. 11 is observed diagonally from the left under similar lighting conditions, that is, when observed from the position of the observer OB3, the display 10 displays an image I1 of a first object and an image I2 of a second object as shown in FIG. 14. That is, the display 10 displays image I1 as if the first object faces diagonally to the right as seen by the observer, and has moved slightly to the right from the state shown in FIG. 12. The display 10 also displays image I2 as if the second object faces diagonally to the right as seen by the observer, with almost no change in position.

In this way, the display 10 shown in FIG. 11 is also configured so that the orientations of the first and second objects in the image displayed by it change continuously according to the change in the observation angle. Furthermore, in this display 10, when the observation angle is changed, the first and second objects in the image displayed by it move relatively in the opposite direction. Therefore, the image displayed by this display 10 appears three-dimensional due to binocular parallax and/or motion parallax. However, in this display 10, when the observation angle is changed, the image I1 is displayed as if the first object has moved slightly, but the image I2 is displayed without changing the position of the second object. Therefore, the amount of relative movement of the first and second objects in the opposite direction in the image displayed by this display 10 is small. Therefore, the three-dimensional image displayed by the display 10 shown in FIG. 11 does not give the observer a stronger sense of three-dimensionality than the three-dimensional image displayed by the display 10 described with reference to FIGS. 1 to 6.

As described above, the display 10 described with reference to Figures 1 to 6 is capable of displaying a three-dimensional image that gives a strong sense of depth to the viewer.

It is preferable to adopt the following design for the display 10.
FIG. 15 is a diagram showing an example of the positional relationship in virtual space between the display bodies of FIGS. 1 and 2 and first and second three-dimensional objects obtained by three-dimensional reconstruction from the three-dimensional images displayed thereby.

As described above, each of the distance D1 _min from the display surface to the first three-dimensional object TOD1 and the distance D2 _min from the display surface to the second three-dimensional object TOD2 is preferably 0.5 mm or more. By increasing each of the distances D1 _min and D2 _min , the viewer can more easily perceive the relative movement of the images of the first and second objects caused by rotating the display body 10.

As described above, the first three-dimensional object TOD1 is preferably located entirely within a range where the distance D1 _max from the display surface is 4 mm or less. Similarly, the second three-dimensional object TOD2 is preferably located entirely within a range where the distance D2 _max from the display surface is 4 mm or less. If the first three-dimensional object TOD1 includes a portion that is far from the display surface, the image of the first object becomes dark at a position corresponding to this portion. Similarly, if the second three-dimensional object TOD2 includes a portion that is far from the display surface, the image of the second object becomes dark at a position corresponding to this portion.

<Modifications of Display Body>
The display 10 described with reference to FIGS. 1 to 6 can be modified in various ways.
FIG. 16 is a cross-sectional view of a display according to a modified example.
The display 10 shown in FIG. 16 is similar to the display 10 described with reference to FIGS. 1 to 6, except that it further includes a print layer 14.

The printing layer 14 is provided on the relief layer 11. The printing layer 14 includes a plurality of line patterns 141 spaced apart from each other and arranged in the width direction. Here, the line patterns 141 each extend in the Y direction and are arranged in the X direction.

The printing layer 14 creates multiple convex portions on the surface of the display body 10. Therefore, like the display body 10 described with reference to Figures 1 to 6, this display body 10 is capable of displaying a three-dimensional image that gives the viewer a strong sense of depth. In addition, it is possible for the viewer to feel a special tactile sensation.

The pattern constituting the printed layer 14, here the line pattern 141, may be light-transmitting or light-shielding. Even in the latter case, the display 10 can display a three-dimensional image that gives a strong stereoscopic effect to the viewer.

Figure 17 shows an image displayed by the display of Figure 16 under certain conditions. Figure 18 shows an image displayed by the display of Figure 16 under other conditions.

When the line pattern 141 is light-blocking, as shown in Figures 17 and 18, the portions of the images I1 and I2 displayed by the relief structure RS that are located directly below the line pattern 141 are hidden by the line pattern 141 and cannot be seen. However, as shown in Figures 17 and 18, when the observation angle is changed, the portions that were hidden by the line pattern 141 become visible.

The height of the protrusions that the printing layer 14 creates on the surface of the display body 10 is preferably within the range of 5 to 40 μm. If the height of the protrusions is small, it will be difficult for an observer to sense the presence of these protrusions by touch when touching the surface of the display body 10. If the height of the protrusions is excessively large, blocking will be more likely to occur. Note that the printing layer 14 with high protrusions can be formed, for example, by intaglio printing.

It is preferable that the width of each of the line patterns 141 is within the range of 0.02 to 0.1 mm. It is also preferable that the line patterns 141 are arranged at a pitch within the range of 0.2 to 0.5 mm.

According to this configuration, adjacent line patterns 141 are unlikely to be connected. In addition, when a viewer touches the surface of the display body 10 employing this configuration, the viewer can easily sense the presence of the convex portions by touch. Furthermore, this configuration is suitable for making a portion of a three-dimensional image that is hidden by the line pattern 141 visible by slightly rotating the display body 10 around an axis A _R that is approximately parallel to the longitudinal direction of the line pattern 141.

<Transfer foil>
FIG. 19 is a cross-sectional view showing an example of a transfer foil.

The transfer foil 2 shown in FIG. 19 includes a support 21 , a transfer material layer 22 , and an adhesive layer 23 .
The support 21 supports the transfer material layer 22 in a peelable manner. The support 21 has, for example, a band shape.

The transfer material layer 22 includes a relief layer 221, a reflective layer 222, a protective layer 223, and a peelable protective layer 224. The peelable protective layer 224, the relief layer 221, the reflective layer 222, and the protective layer 223 are laminated in this order on the support 21. The laminated order of the relief layer 221, the reflective layer 222, and the protective layer 223 may be reversed.

The transfer material layer 22 includes a transfer portion that is transferred to an article by application of heat and pressure, and a non-transfer portion that is not transferred to an article. The transfer portion is the portion that is used as the display body 10 described above. Therefore, the portion of the relief layer 221 located in the transfer portion, the portion of the reflective layer 222 located in the transfer portion, and the portion of the protective layer 223 located in the transfer portion correspond to the relief layer 11, the reflective layer 12, and the protective layer 13, respectively.

The peel-off protective layer 224 is provided adjacent to the support 21. The peel-off protective layer 224 is made of a material that is optically transparent, for example, a colorless and transparent material. The peel-off protective layer 224 can be omitted.

The adhesive layer 23 faces the support 21 with the transfer material layer 22 sandwiched therebetween. The base material of the adhesive layer can be a thermoplastic resin. The resin component can be an acrylic resin. The acrylic resin can be polymethyl methacrylate or the like. The transfer foil 2 may or may not include the adhesive layer 23.

<Adhesive labels>
FIG. 20 is a cross-sectional view showing an example of an adhesive label.

The adhesive label 3 shown in FIG. 20 includes a display body 31 and an adhesive layer 32. In FIG. 20, the reference numeral 33 denotes a release sheet.

The display body 31 includes a substrate 311, a reflective layer 312, and a protective layer 313. The display body 31 corresponds to the display body 10 described above. Therefore, the substrate 311, the reflective layer 312, and the protective layer 313 correspond to the relief layer 11, the reflective layer 12, and the protective layer 13, respectively.

The adhesive layer 32 is provided on one of the main surfaces of the display body 31. The adhesive layer 32 is protected by a release sheet 33 until immediately before the adhesive label 3 is used.

The adhesive layer 32 is made of an adhesive such as a pressure-sensitive adhesive. Examples of adhesives that can be used include vinyl chloride-vinyl acetate copolymer, polyester polyamide, or acrylic, butyl rubber, natural rubber, silicone, or polyisobutyl adhesives.

The adhesive may further contain additives. Examples of additives include aggregating components such as alkyl methacrylates, vinyl esters, acrylonitrile, styrene, and vinyl monomers; modifying components such as unsaturated carboxylic acids, hydroxyl group-containing monomers, and acrylonitrile; polymerization initiators; plasticizers; curing agents; curing accelerators; antioxidants; or mixtures containing two or more of these.

<Items with display>
FIG. 21 is a plan view showing an example of an article with a display member.

The display-attached article 4 shown in FIG. 21 is a printed matter. The display-attached article 4 is, for example, a personal authentication medium such as a banknote, a security, a certificate, a credit card, a passport, or an ID (identification) card, or a package that wraps the contents.

This display-equipped item 4 includes a display 41 and an item 42 that supports it.

The display body 41 is the display body 10 described above. The display body 41 is supported by the item 42, for example, by being attached to the surface of the item 42 or being embedded within the item 42.

The article 42 includes an article body 421, such as a printing substrate, and a printing layer 422 provided thereon. The material of the article body 421 is, for example, plastic, metal, paper, or a composite of these.

In the following, examples of the present invention are described.
(Example 1)
The transfer foil 2 described with reference to Fig. 19 was manufactured. The protective layer 223 was omitted. The transfer material layer 22 had the structure described for the display body 10 with reference to Figs. 1 to 6 and 15.

Here, the first three-dimensional object TOD1 is a star shape with no thickness, and each of the distances D1 _min and D1 _max is 2 mm. The second three-dimensional object TOD2 is a moon shape with no thickness, and each of the distances D2 _min and D2 _max is 2 mm.

The relief structure RS uses the structure described in International Publication No. WO 2017/209113. Specifically, each of the first three-dimensional object TOD1 and the second three-dimensional object TOD2 is divided into square regions with sides each having a length of 100 μm, and the viewing angles in the X and Y directions are each set to 20°. In addition, the minimum size of the pattern contained in the relief structure RS is set to 400 nm, and the depth is set to four levels.

In the manufacture of the transfer foil 2, first, a nickel plate was manufactured. Specifically, a pattern corresponding to the relief structure RS was drawn on the surface of the resist layer using an electron beam drawing device. Next, nickel was sputtered onto this surface, and further nickel was plated. After that, the resist layer was removed from the nickel layer. In this manner, a nickel plate was obtained.

Next, a film made of polyethylene terephthalate was prepared as the support 21, and a liquid containing polymethyl methacrylic acid and polyethylene wax was applied thereon to form a peelable protective layer 224. Next, a layer containing acrylic polyol, isocyanate, and fluororesin was formed on the peelable protective layer 224. The nickel plate described above was attached to this layer, and a heated roll set at 150°C was pressed against it while ultraviolet light was applied to transfer the pattern of the plate. This resulted in a relief layer 221.

After the laminate including the relief layer 221, the release protective layer 224, and the support 21 was peeled off from the plate, aluminum was deposited on the relief layer 221 to form a reflective layer 222. Furthermore, an ethylene-vinyl acetate copolymer was applied onto the reflective layer 222 to form an adhesive layer 23.
In this manner, a transfer foil 2 shown in FIG. 19 was obtained.

Next, this transfer foil 2 was used to manufacture an article with a display body. Here, fine paper was used as the article on which the display body was to be supported. In manufacturing the article with a display body, the transfer foil 2 was layered on the fine paper, and in this state, heat and pressure were applied to a part of the laminate. Next, the support 21 was peeled off from the fine paper together with the part of the transfer material layer 22 to which heat and pressure had not been applied. In this way, the part of the transfer material layer 22 to which heat and pressure had been applied was transferred from the support 21 to the fine paper as the display body 10. In this manner, an article with a display body was obtained.

This display-equipped article was illuminated with white light, and the three-dimensional image displayed by the display 10 was observed with the naked eye. As a result, it was confirmed that the display 10 displayed a three-dimensional image that gave the observer a strong sense of depth.

Comparative Example
An article with a display body was manufactured in the same manner as in Example 1, except that the relief structure RS was designed so that the second three-dimensional object TOD2 would not be restored when the three-dimensional image was three-dimensionally restored.

This display-equipped article was illuminated with white light, and the three-dimensional image displayed by the display was observed with the naked eye. As a result, it was confirmed that this display does not give the observer a strong sense of three-dimensionality as display 10 in Example 1 does.

(Example 2)
An article with a display was manufactured in the same manner as in Example 1, except that after a portion of the transfer material layer 22 was transferred from the support 21 to the wood-free paper, the printed layer 14 was formed as described with reference to Figures 16 to 18. Here, the printed layer 14 was formed by intaglio printing. The thickness of the printed layer 14 was 15 μm, the width of the line pattern 141 was 0.05 mm, and the pitch of the line pattern 141 was 0.3 mm.

The article with the display body was illuminated with white light, and the three-dimensional image displayed by the display body 10 was observed with the naked eye. As a result, under certain conditions, the parts of the images I1 and I2 located directly below the line pattern 141 were hidden by the line pattern 141 and could not be seen, but by changing the observation angle, the parts hidden by the line pattern 141 that were not visible became visible. It was also confirmed that the display body 10 gives a stronger three-dimensional feeling to the observer than the display body of the comparative example. Furthermore, by touching the printed layer 14 of the display body 10, the unevenness caused by the line pattern 141 could be recognized as a difference in tactile sensation from other parts.
The invention as originally claimed is set forth below.
[1]
A display device that displays a three-dimensional image including an image of a first object and an image of a second object as a diffraction image,
When a three-dimensional object is three-dimensionally restored from the three-dimensional image,
a first three-dimensional object corresponding to the first target object is restored to a position in front of a display surface of the display body as viewed by an observer who observes the display body, and is spaced apart from the display surface;
a second three-dimensional object corresponding to the second object is restored to a position behind the display surface as viewed by the observer, and separated from the display surface;
A display body in which no other three-dimensional object is restored between the first three-dimensional object and the second three-dimensional object.
[2]
2. The display according to item 1, wherein the image of the first object and the image of the second object at least partially overlap each other when the display is observed from the front.
[3]
3. The display according to item 1 or 2, wherein each of the distance from the display surface to the first three-dimensional object and the distance from the display surface to the second three-dimensional object is 0.5 mm or more.
[4]
4. The display according to any one of claims 1 to 3, wherein each of the first three-dimensional object and the second three-dimensional object is located entirely within a range of a distance of 4 mm or less from the display surface.
[5]
The display body according to any one of claims 1 to 4, wherein the distance from the display surface to the position on the surface of the first three-dimensional object farthest from the display surface is equal to the distance from the display surface to the position on the surface of the second three-dimensional object farthest from the display surface.
[6]
The display body according to any one of claims 1 to 4, wherein a distance from the display surface to a position on the surface of the first three-dimensional object farthest from the display surface is shorter than a distance from the display surface to a position on the surface of the second three-dimensional object farthest from the display surface.
[7]
a relief layer having a relief structure displaying the three-dimensional image on one main surface thereof;
a reflective layer at least partially covering the area of the main surface where the relief structure is provided;
7. The display according to any one of items 1 to 6, wherein the display surface is a surface of the reflective layer or an interface between the relief structure and the reflective layer.
[8]
8. The display according to item 7, wherein the three-dimensional image is recorded as interference fringes in the relief structure.
[9]
Item 9. The display according to item 7 or 8, further comprising a printed layer facing the display surface, the printed layer forming a plurality of protrusions on the surface of the display.
[10]
10. The display according to item 9, wherein the height of the plurality of protrusions is within a range of 5 to 40 μm.
[11]
Item 11. The display according to item 9 or 10, wherein the plurality of protrusions include a plurality of line patterns spaced apart from each other and arranged in the width direction.
[12]
Item 12. The display according to item 11, wherein the width of each of the plurality of line patterns is within a range of 0.02 to 0.1 mm, and the plurality of line patterns are arranged at a pitch within a range of 0.2 to 0.5 mm.
[13]
A transfer material layer including the display body according to any one of items 1 to 12,
A support on which the transfer material layer is supported in a peelable manner;
A transfer foil equipped with
[14]
A display according to any one of items 1 to 12,
An adhesive layer provided on the display body;
An adhesive label comprising:
[15]
A display according to any one of items 1 to 12,
An article supporting the display body;
An article with a display body comprising:

2...transfer foil, 3...adhesive label, 4...article with display body, 10...display body, 11...relief layer, 12...reflective layer, 13...protective layer, 14...printed layer, 21...support, 22...transfer material layer, 23...adhesive layer, 31...display body, 32...adhesive layer, 33...release sheet, 41...display body, 42...article, 141...line pattern, 221...relief layer, 222...reflective layer, 223...protective layer, 224...release protective layer, 421...article body, 422...printed layer, A _R ...axis, I1...image, I2...image, OB1...observer, OB2...observer, OB3...observer, R1...first region, R2...second region, RS...relief structure, TOD1...first three-dimensional object, TOD2...second three-dimensional object.

Claims (13)

A display device that displays a three-dimensional image including an image of a first object and an image of a second object as a diffraction image,
When a three-dimensional object is three-dimensionally restored from the three-dimensional image,
a first three-dimensional object corresponding to the first object is restored to a position in front of a display surface of the display body as viewed by an observer who observes the display body, and is spaced apart from the display surface;
a second three-dimensional object corresponding to the second object is restored to a position behind the display surface as viewed by the observer, and separated from the display surface;
No other three-dimensional object is restored between the first three-dimensional object and the second three-dimensional object,
the three-dimensional image is an image displayed by a diffraction grating;
a relief layer having a relief structure as the diffraction grating for displaying the three-dimensional image on one main surface thereof;
a reflective layer at least partially covering the area of the main surface where the relief structure is provided;
wherein the display surface is a surface of the reflective layer or an interface between the relief structure and the reflective layer . The display according to claim 1, wherein the image of the first object and the image of the second object at least partially overlap when the display is observed from the front. The display according to claim 1 or 2, wherein the distance from the display surface to the first three-dimensional object and the distance from the display surface to the second three-dimensional object are each 0.5 mm or more. The display according to any one of claims 1 to 3, wherein each of the first three-dimensional object and the second three-dimensional object is located entirely within a distance of 4 mm or less from the display surface. The display according to any one of claims 1 to 4, wherein the distance from the display surface to the position on the surface of the first three-dimensional object farthest from the display surface is equal to the distance from the display surface to the position on the surface of the second three-dimensional object farthest from the display surface. The display according to any one of claims 1 to 4, wherein the distance from the display surface to the position on the surface of the first three-dimensional object farthest from the display surface is shorter than the distance from the display surface to the position on the surface of the second three-dimensional object farthest from the display surface. The display according to claim 1 , further comprising a print layer facing the display surface, the print layer forming a plurality of protrusions on the surface of the display. The display according to claim 7 , wherein the height of the plurality of protrusions is within a range of 5 to 40 μm. The display according to claim 7 or 8 , wherein the plurality of protrusions include a plurality of line patterns spaced apart from each other and arranged in the width direction. 10. The display according to claim 9 , wherein the width of each of the plurality of line patterns is within a range of 0.02 to 0.1 mm, and the plurality of line patterns are arranged at a pitch within a range of 0.2 to 0.5 mm. A transfer material layer including the display body according to any one of claims 1 to 10 ;
A transfer foil comprising: a support that supports the transfer material layer in a peelable manner. A display according to any one of claims 1 to 10 ;
and an adhesive layer provided on the display body. A display according to any one of claims 1 to 10 ;
and an article supporting the display body.