CH714544B1 - Synthetic image device with locking features. - Google Patents

Abstract

A synthetic image device (1) comprises an image layer and a focusing element array. Composite image objects of the image layer are an aggregation of at least a first and a second set of image objects. The first set of image objects is arranged to result in a synthetic guide image (41). The synthetic guide image, when moved in one direction for viewing, presents a first sub-image and a second sub-image, thereby moving them into a predetermined geometric relationship with respect to one another. The second set of image objects is arranged to result in a synthetic effect image (42) within a limited effect field of view. The limited effect field of view is selected such that it includes viewing directions in only a set of separate directions or excludes viewing directions in only a set of separate directions.

Description

TECHNICAL AREA

The present invention relates generally to optical devices and manufacturing processes therefor, and more particularly to synthetic image devices and manufacturing methods therefor.

BACKGROUND ART

[0002] Synthetic image devices are now often used to create striking visual effects for many different purposes. Application examples are e.g. B. security markings, tamper indicators or simply aesthetic images. Normally, the synthetic image device is intended to be provided as a label or as an integrated part in another device. Many different visual effects have been discovered and used, and often different visual effects are combined to give a particular required visual appearance.

A typical synthetic image device is an array of small focusing elements and image objects created on different planes of a thin sheet. The focusing element can be different types of lenses, apertures or reflectors. An image layer is provided with image objects. The image layer is provided relative to the array of focusing elements such that when the device is viewed from different angles, different parts of the image objects are magnified by the focusing elements and together form an integral image. Depending on the configuration of the image objects, the synthetic image can change in various ways if the viewing directions, e.g. B. viewing angle can be changed. A typical implementation of the synthetic image device is a thin polymer film.

The actual perception of the synthetic image occurs through the user's eye and brain. The human brain's ability to create an intelligible ensemble from fragmented sub-images can be used to create a 'surprise effect'. Such eye-catching effects are often used for security and/or authentication purposes.

When the focusing elements and the image objects are perfectly aligned, the intended "central" synthetic image can be seen by viewing the synthetic image device from a direction perpendicular to the plane of the focusing elements. However, the alignment of the focusing elements and the image objects is not very easy to achieve, at least in mass production lines, since existing alignment techniques are expensive to implement.

If the focusing elements and the image objects are instead offset, the intended "central" synthetic image is instead seen from a different direction that is not perpendicular to the plane of the focusing elements. A "surprise effect" is often provided in the intended "central" synthetic image, as this direction is assumed to be easy to find. However, when misalignment is present, the "surprise effect" can be difficult to find because the viewer does not know at what viewing angle relative to the surface of the synthetic imaging device to look for the "surprise effect". Authentication or security checks can therefore be difficult to perform in the same way.

Examples of synthetic image devices representing different types of concurrent synthetic sub-images are disclosed in published international patent application WO 2015/034551 A .

EXECUTIVE SUMMARY

A general objective with the technology presented herein is to improve the ability to find specific viewing angles of synthetic images.

The above object is achieved by methods and devices according to the independent claims. Preferred embodiments are defined in the dependent claims.

In general terms, in a first aspect, a synthetic image apparatus includes an image layer and a focusing element array. The image layer is located near a focal length of the focusing elements of the focusing element array. Composite image objects of the image layer are an amalgamation of at least a first set of image objects and a second set of image objects. The first set of image objects is arranged to result in at least a first synthetic guide image when placed near a focal length of the focusing elements and viewed through the focusing element array. The synthetic guide image, when moved for viewing in one of a set of separate directions, presents a first sub-image and a second sub-image, thereby moving them into a predetermined geometric relationship with respect to one another. The second set of image objects is arranged to result in at least a second synthetic effect image within a limited effect field of view of the synthetic effect image when placed near a focal length of the focusing elements and viewed through the focusing element array. The limited effect field of view of the synthetic effect image is selected such that it includes viewing directions only in angular proximity to any of the directions of the set of separate directions or excludes viewing directions only in angular proximity to any of the directions of the set of separate directions.

In a second aspect, a method of manufacturing a synthetic image apparatus includes generating a numerical representation of a first set of image objects arranged in image cells to result in at least a first synthetic guide image when in proximity a focal length of the focusing elements and viewed through a focusing element array. The synthetic guidance image represents a first partial image and a second partial image, with a relative geometric relationship to one another being changed when a viewing direction is changed. A predetermined relative geometric relationship between the first sub-image and the second sub-image corresponds to image objects positioned at a first position in each image cell. An effect view boundary area is defined, comprising the first position and an edge. A numerical representation of a second set of image objects is generated which is arranged to result in at least one second synthetic effect image when placed near a focal length of the focusing elements and viewed through the focusing element array. The numerical representation of the second set of image objects is modified within or outside the effect view bounding area to result in an abrupt change in the appearance of the synthetic effect image. The numeric representation of the first set of image objects and the numeric representation of the second set of image objects are combined into a numeric representation of composite image objects. An image layer is formed according to the numerical representation of composite image objects. A focusing element array is formed with the image layer located in a vicinity of a focal length (of the focusing elements of the focusing element array).

In a third aspect, a method of authenticating an object with a synthetic image device provided on a surface of the object includes observing a first guide synthetic image of the synthetic image device in a viewing direction. The synthetic guide image has a first sub-image and a second sub-image. The synthetic image device is moved to change the viewing direction to cause the first partial image and the second partial image to move to a predetermined relative geometric relationship with respect to each other. An abrupt change in the appearance of a second synthetic effect image is observed as an indication of authenticity when it is moved to the predetermined relative geometric relationship.

An advantage of the proposed technology is that surprise effects in the synthetic images of synthetic image devices are easily found without the need for translational alignment of the image layer and the focusing element array. Other advantages will become apparent upon reading the detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention, together with other objects and advantages thereof, may be best understood by reference to the following description in connection with the accompanying drawings, in which: FIG. 1A-C are schematic drawings of synthetic image devices using different focusing elements; FIG. Figure 2 is a schematic drawing illustrating viewing from different angles; FIG. 3A-B illustrate the formation of a synthetic image for two different viewing angles; FIG. 4A-C illustrate the concepts for forming an example of a one-piece synthetic image device; FIG. Figure 5 illustrates another example of a one-piece synthetic image device; FIG. Figure 6 illustrates an example of how a three-dimensional image can be generated; FIG. Figure 7 is an example of image objects of an integrated synthetic image device; FIG. 8A illustrates an embodiment of a synthetic image device with a synthetic guide image; FIG. 8B illustrates the embodiment of FIG. 8A when tilted; FIG. 8C illustrates a relationship between a viewer and a synthetic guide image; FIG. 8D illustrates the embodiment of FIG. 8A when tilted and having a synthetic effect image; FIG. 8E illustrates a limited effect field of view; FIG. 9A-C illustrate other embodiments of a synthetic image device with a synthetic guide image; FIG. Figure 10 illustrates different viewing directions that yield a predetermined geometric relationship in the synthetic guidance image; FIG. Figure 11 illustrates another embodiment of a synthetic image device with a synthetic guide image; FIG. 12A-B illustrate another embodiment of a synthetic image device with a guide synthetic image in perspective and top view; FIG. 13A-B illustrate yet another embodiment of a synthetic image device with a guide synthetic image in perspective and top view; FIG. 14A-B illustrate an embodiment of a synthetic image device with a three layer synthetic guide image; FIG. 15A-B illustrate embodiments of a synthetic image device with a three-dimensional synthetic guidance image; FIG. 16A-B illustrate other embodiments of a synthetic image device with a synthetic guide image; FIG. 17A-H illustrate embodiments of a synthetic image device with a synthetic effect image; FIG. 18 illustrates an embodiment of a synthetic image apparatus having a two-level synthetic guide image and a synthetic effect image; FIG. 19 is a flow chart of steps of one embodiment of an authentication method; FIG. 20A-C illustrate embodiments of cells in a synthetic image device with a synthetic guide image; FIG. 21A-J illustrate embodiments of a cell in a synthetic image device; FIG. 22A-C illustrate embodiments of cells in a synthetic image device; FIG. 23A-B illustrate a relationship between a cell position and an associated focusing element; FIG. 24 is a flow chart of steps of one embodiment of a manufacturing method; FIG. 25A-B illustrate relationships between cells and associated focusing elements; FIG. Figure 26 schematically illustrates an embodiment of a synthetic image apparatus having cells with a plurality of channels; FIG. 27A-B schematically illustrate an embodiment of a synthetic image apparatus having cells with a plurality of channels; FIG. 27C-D schematically illustrate another embodiment of a synthetic image apparatus having cells with a plurality of channels; FIG. Figure 28 schematically illustrates another embodiment of a synthetic image apparatus having cells with a plurality of channels; FIG. 29A-B schematically illustrate embodiments of a synthetic image apparatus displaying synthetic morph images; FIG. Figure 30 schematically illustrates an embodiment of a synthetic image apparatus displaying a combined synthetic morph image; and FIG. 31A-C schematically illustrate another embodiment of a synthetic image apparatus that presents a combined synthetic image.

DETAILED DESCRIPTION

In the drawings, the same reference numbers are used for similar or corresponding elements.

For a better understanding of the proposed technology, it may be useful to start with a brief overview of the synthetic image devices.

[0017] FIG. 1A schematically illustrates an example of a synthetic image device 1 . The synthetic image device 1 comprises a focusing element array 20 of focusing elements 22. In this example the focusing element is a lens 24. In a typical case where the synthetic image is to be substantially the same in different surface directions, the lens 24 is typically a spherical one Lens. In applications where there is a difference between image properties in different surface directions, a lenticular lens can be used.

The synthetic image device 1 further comprises an image layer 10 comprising image objects 12 . The image objects 12 are objects which can be distinguished optically from parts 14 of the image layer 10 which cannot be covered by image objects 12 . The image objects 12 can, for. B. consist of printed product micro-features 11 and / or embossed microstructures. The image layer 10 is located near a focal length d of the focusing elements 22 of the focusing element array 20 . That is, a parallel beam 6 of light striking a focusing element 22 is refracted 5 and focused at a point or small area 4 on the image layer 10 . Likewise, light emerging from a point on the image layer 10 results in a parallel beam 6 of light as it traverses the focusing elements 22. FIG. A point on an image object 12 therefore appears to fill the entire surface of the focusing element 22 when viewed from a distance in the direction of the generated parallel beam 6 by a viewer, as illustrated schematically by the viewer's 2 eye. The material 9 between the image layer 10 and the focusing element array 20 is at least partially transparent and typically consists of a thin polymer film.

The distance d does not have to be exactly equal to the focusing distance of the focusing elements 22. There is always some degree of aberration first, which expands the area from which the optical information is collected in a parallel beam 6 . This appears more pronounced at shallower angles and in order to have a more consistent general level of resolution, a distance close to but not exactly equal to the focal length can advantageously be chosen. In addition, since the surface of the focusing element has a certain two-dimensional extension, this surface could also be used to create fine objects of the synthetic overall image. In such cases, fine objects of a small area on the image layer 10 may be advantageous for magnifying to cover the surface of the focusing element, which means that even in such a case the actual selected distance d is chosen to be in a vicinity, but not exactly equal to the focal length. Such circumstances are well known in the art of synthetic images.

By arranging the image objects 12 of the image layer 10 in a suitable way, the partial images generated at the surface of each individual focusing element 22 are perceived by a viewer 2 as a synthetic image together. Different images can be displayed to the viewer when the synthetic image device 1 is viewed from different directions, thereby creating different types of visual effects as will be described in more detail below.

FIG. 1B schematically illustrates another example of a synthetic image device 1 . In this embodiment, the focusing elements 22 consist of concave mirrors 26. The image layer 10 is here on the front surface with respect to the viewer 2, and the focusing element array 20 is behind the image layer 10. The rays 5 of light emanating from the image objects moved to the viewer 2 pass through the material 9 of the synthetic image device twice.

FIG. 1C schematically illustrates yet another example of a synthetic image device 1 . In this embodiment, the focusing elements are pinholes 28 which restrict the light coming from the image layer 10 and passing through to the viewer 2. FIG. In this embodiment, the synthetic image is formed by the narrow rays of light passing through the pinholes 28 and typically provides only "light" or "dark". Because the pinholes 28 have no magnifying effect, most of the surface viewed does not contribute to the synthetic image.

Figure 2 schematically illustrates the selection of different sub-regions 4 of the image layer 10. The image layer 10 comprises image objects 12. When the synthetic image device 1 is viewed in a perpendicular direction with respect to the main surface of the synthetic image device 1, As illustrated in the left part of the drawings, the area 4 enlarged by the focusing element 22 is located at the center line, as shown by a broken line in the figure, of the focusing element 22. When an image object 12 is present at this position , an enlarged version is displayed on the surface of the synthetic image device 1 . However, as in the case of FIG. 2, there is no image object and there will be no enlarged image on the surface of the synthetic image device 1. FIG.

When viewing the synthetic image device 1 at a different angle, e.g. B. illustrated in the right part of the figure, the area 4 on which the focusing element 22 is focused is shifted to the side. In the illustrated situation, the region 4 overlaps at least part of an image object 12 and an enlarged version can be seen on the surface of the synthetic image device 1 . In this way, the images presented on the surface of the synthetic image device 1 can change for different viewing angles, which can be used to achieve different types of optical effects of the synthetic images.

One type of synthetic image is a so-called moiré image. The moiré effect has been well known for many years and is due to the interaction of two slightly mismatched configurations. Fig. 3A schematically illustrates in the upper part an example of a part of an image layer 10. The image layer 10 comprises a repeating pattern 15 of image objects 12. In this example the image objects 12 are selected such that they are the letter "K." “ acts. The focusing elements 22 associated with the illustrated portion of the image layer 10 are illustrated by dotted circles to indicate relative lateral position. Both the repeating pattern 15 of the image objects 12 and the focusing element arrangement 20 have a hexagonal symmetry. However, the distance between two adjacent image objects 12 is slightly shorter than the distance between two adjacent focusing elements 22 in the same direction.

An area 4 corresponding to the focusing area of each focusing element 22 is also identified. In the illustrated case, the area 4 corresponds to a viewing direction straight ahead. The parts of the image objects 12 present in each of the regions 4 are thereby displayed in an enlarged version over the surface of the corresponding focusing element 22, referred to herein as a projected image 25. In the lower part of FIG. 3A the corresponding focusing element arrangement 20 is illustrated such that it encloses the projected images 25 of the image objects 12 of the regions 4 . The dotted lines from one of the areas 4 in the upper part to one of the focusing elements 22 in the lower part illustrate the association. The various projected images at the focusing elements 22 together form a synthetic image 100. In this case, the synthetic image 100 is part of a capital "K". If these structures are small enough, the human eye typically fills in the empty areas between the focusing elements 22 and the viewer perceives a full "K". The reason for the generation of the K is the existence of the slight mismatch in distance between the repeating pattern 15 of image objects 12 and the focusing element array 20. In this example, the synthetic image is created using the mismatch between a repeating image pattern 15 and an array of Focusing elements 22 referred to as a moiré image 105.

Figure 3B schematically illustrates the same synthetic image device 1 as in Figure 3A, but viewed from a different direction. This corresponds to a slight inclination of the synthetic image device 1 to the left. The areas 4 corresponding to the focusing areas of the focusing elements 22 in this direction are thereby moved somewhat to the left. This results in another part of the image objects 12 being projected towards the focusing elements 22, as can be seen in the lower part of FIG. 3B. The result of the tilting is that the synthetic image 100, i. H. the capital "K", moving to the right.

The viewer interprets such movement as a result of a position of the capital "K" at a certain imaginary depth below the surface of the synthetic image device 1 . In other words, a feeling of depth is achieved. Both the magnification and the detected depth depend on the relationship between the focusing element array 20 and the repeating pattern 15 of the image objects 12. In the prior art it has been shown that the obtained magnification M is determined as follows: where Po is the distance of the repeating pattern 15 of the image objects 12 and Pl is the distance of the focusing element array 20. For Po< Plist the magnification is positive, for Po> Pl the magnification becomes negative, i.e. H. the synthetic image 100 is reversed compared to the image objects 12.

The discernible image depth di in the moiré image can also be determined as follows: di= (d-Rl)/(1-F)+Rl, (2) where d is the thickness of the synthetic imaging device and Rl is the radius of curvature of the spherical microlenses. One can see here that for Po< Pl the discernible depth is typically positive, while for Po > Pl the discernible depth becomes negative, i.e. H. the moire image 105 appears to be floating above the surface of the synthetic image device 1 .

It should be noted that the differences in the distances illustrated in Figures 3A and 3B are relatively large, resulting in relatively low magnification and relatively low apparent depth. This is for illustrative purposes. In typical synthetic moiré devices, the relative differences in distances can typically be much smaller. Differences in distances of less than 1% and even less than 0.1% are not uncommon.

However, the moiré images have certain limitations. At first, they can only lead to repetitive images. In addition, the size of the image objects 12 is limited to the size of the focusing elements. An image object 13 is illustrated schematically in FIG. 4A. When this image object is repeated at almost the same distance as for the focusing elements 22 of Fig. 4B, the repeated patterns of image objects 13 overlap Image objects associated with an adjacent focusing element 22 interfere.

A solution is shown in Figure 4C. Here a cell 16 of the image layer 10 is associated exclusively with each focusing element 22 . In each cell 16 only parts of an image object 17 belonging to a copy of the image object are kept and the other interfering image objects are removed. The various image objects 17 are now not repeated identically over the image layer 10, but instead the shape of the image objects 17 changes one after the other. By using these cut out parts or pieces as the image object 17, a synthetic image is also created. A synthetic image based on non-identical fractional image objects 17 within the cells 16 associated with the focusing elements 22 is referred to in this disclosure as a unitary synthetic image.

As long as the focussing range of the associated focussing element is maintained in the cell 16, a synthetic image resembling a moiré image is produced. However, when the focus range of the associated focus element enters an adjacent cell 16, the synthetic image immediately disappears and instead appears at a different position; there is a reversal of the synthetic image.

Such reversal effects can be mitigated somewhat by introducing an image object-free zone between each cell at the image layer. Figure 5 schematically illustrates such an embodiment. Here, each cell 16 occupies an area smaller than an area of an associated focusing element. The result is that the integral synthetic image disappears when the focal area of the associated focusing element reaches the edge of the cell. However, a further change in viewing angle must be provided before a "new" integral synthetic image appears. The relationship to the vanishing image is then not equally recognizable. This limitation of the angles at which a synthetic image can be viewed is often referred to as a restricted field of view.

The concepts of having cells with different image objects can be further advanced. The synthetic moiré images can be given a recognizable depth, but are in principle limited to only one depth. A true three-dimensional appearance is difficult to achieve. However, when considering integral synthetic images, the freedom of changing the image objects from one cell to another can also be used, e.g. B. to provide a more realistic three-dimensionality of the generated images.

In Figure 6, cells 16 of an image layer 10 are illustrated. Four different regions 4 for each cell 16, corresponding to focusing regions of associated focusing elements when viewed from four different directions, are illustrated. Center region image objects 4 in each cell correspond to a viewing angle achieved when the synthetic image device is viewed in a perpendicular manner. Such image objects can then be configured to result in an integral synthetic image 110B, as illustrated in the lower middle portion of FIG. 6, which shows a top surface of a box. Image objects of the top region 4 in each cell correspond to a viewing angle achieved when the synthetic image device is tilted away from the viewer. Such image objects can then be designed to result in an integral synthetic image 110A, as illustrated in the lower left portion of FIG. 6, which shows the top surface and a front surface of a box. Image objects of the leftmost area 4 in each cell correspond to a viewing angle achieved when the synthetic image device is tilted to the left with respect to the viewer. Such image objects can then be configured to result in an integral synthetic image 110C, as illustrated in the lower right portion of FIG. 6, which shows the top surface and a side surface of a box. Image objects of area 4 in the rightmost part in each cell correspond to a viewing angle obtained when the synthetic image device is tilted towards and to the right with respect to the viewer. Such image objects can then be configured to result in an integral synthetic image 110D, as illustrated at the bottom of Figure 6, which shows the top surface, a side surface, and a back surface of a box. Together, these integral synthetic images 110A-D, and also integral synthetic images derived from other regions of the cells, give an impression of a rotating box in a three-dimensional manner.

In a similar way, different types of optical phenomena can be achieved by modifying the image content in each cell separately. By adjusting each part of the cell according to the required appearance of the image in a corresponding viewing direction, the integral synthetic image can be made to have almost any appearance. The image properties achieved in this way can be simulations of "real" optical properties, e.g. B. a real three-dimensional image, but the image properties can also show optical effects that are not present in "real system".

An example of a portion of an image layer 10 of an integral synthetic image apparatus resulting in an image of figure "5" is illustrated in FIG.

An effect that is possible to achieve both synthetic moiré images and integral synthetic images is that two or more synthetic images can be imaged simultaneously. These synthetic images may have different apparent depth or height. When navigating such an optical device, the synthetic images each move relatively according to the usual parallax effect. The same is true when a one-piece synthetic image has components at different depths or heights.

According to the technology presented here, such a parallax effect can be used to define certain different viewing directions. If the integral synthetic image has an easily identified appearance when viewed from a particular direction, that particular direction is defined with the integral synthetic image itself. This also means that a search for that easily identified appearance of the integral synthetic image also becomes a search for that particular viewing direction.

An example schematically illustrated in Figures 8A-B may perhaps facilitate understanding. In this particular example, a synthetic image device 1 presents a synthetic guide image 41 composed of a first sub-image 46, which in this embodiment is an array of circles 71, located at an apparent depth below the surface of the device 1 for synthetic images, and a second partial image 47, which in this embodiment is an array of crosses 72, provided at an apparent height above the surface of the synthetic image device 1. When viewed from the direction illustrated in FIG. 8A , the crosses 72 appear to be to the right relative to a respective circle 71 .

In order to try to get the cross 72 in the center of the circle 71, it is natural for a person to tilt the synthetic image device 1 to the left. This occurs according to a natural three-dimensional parallax rule since the crosses 72 appear to be at a higher elevation than the circles 71. In such an inclined viewing direction, the synthetic image device 1 provides a synthetic guide image 41 as illustrated in Fig. 8B. Such a maneuver is easily performed by any person since the relative movement of the various parts of the synthetic guidance image 41 occurs in a traditional three-dimensional manner.

As schematically illustrated in Figure 8C, the viewing angle at which the circles 71 and the crosses 72 are aligned defines a certain direction d with respect to the surface of the synthetic image device 1.

By combining such an integral synthetic image with another synthetic image with a narrow limited field of view centered around that particular direction, a surprise effect can be achieved. Alternatively, the other synthetic image may have a limited field of view that excludes a small angular interval about that particular direction.

Stated another way, a recognizable three-dimensional synthetic image can be used to guide a viewer to a specific viewing angle. At this viewing angle, there is something "surprising" about the three-dimensional synthetic image or an additional synthetic image. Because the relative orientation of the image objects belonging to different synthetic images is simple, the "surprise effect" can be more or less perfectly aligned with the shape of the three-dimensional synthetic guide image.

An example of a synthetic image device 1 with such a surprise effect is illustrated in Fig. 8D. The synthetic image device 1 presents the same synthetic image as in Figure 8A when viewed from this viewing direction. However, when the synthetic image device 1 is tilted to give the same viewing direction d as illustrated in Figs. 8B and 8C, a synthetic effect image 42 of Fig. 8D appears which has the words "AUTHENTIC PRODUCT" over a large portion of the synthetic image device 1 shows. This particular effect is achieved by imparting a limited guidance field of view to the synthetic guidance image, as seen in Figure 8A, where the limited guidance field of view excludes viewing directions in a vicinity of the "aligned cross/circle" direction. The boundary of such a limited guidance field of view 51 is illustrated in Figure 8E. This means that the crosses and circles disappear at or near this direction d. At the same time, an additional synthetic effect image 42, which gives the text, is provided. In addition, this synthetic effect image 42 has a limited effect field of view 52, which is instead limited to a small angular interval about the direction d of "aligned cross/circle" (Figure 8E). This means that the text "AUTHENTIC PRODUCT" only appears very close to this direction d. The circles 71 and crosses 72 define an object that is very easy to tilt to a specific angle, and thus the circles 71 and crosses 72 serve as a guide for the viewer as to where the "surprise effect" is to be found. When the certain direction is reached, or shortly before, the circles 71 and crosses 72 suddenly disappear and the authenticity text appears instead.

In devices according to the technology presented here, at least two sets of image objects are provided, each resulting in a particular synthetic image. Synthetic imagers such as those described above are well known in the art. Also, a combination of two or more synthetic images into a synthetic image device as such is already known. However, the concepts presented here are based on the further fact that although the two sets of image objects result in independent synthetic images, there is a certain relationship between the two sets in terms of field of view. In other words, the two sets of image objects are connected to each other in the field of view area. The first set, referred to herein as a synthetic guidance image, has a well-defined viewing direction in which the synthetic guidance image represents a natural "aligned" synthetic image. With this very same viewing direction, defined based on the properties of the synthetic guide image, the synthetic image based on the second set of image objects, referred to herein as a synthetic effect image, provides an effect of surprise, such as the appearance, disappearance, or presentation of a abrupt non-logical change in appearance. Thus, there is a very specific relationship of field of view angles between the two sets of image objects, which sets may be entirely independent in other respects.

In general and in other words, a synthetic image device comprises an image layer and a focusing element array. The image layer is located near a focal length of the focusing elements of the focusing element array. Composite image objects of the image layer are an amalgamation of at least a first set of image objects and a second set of image objects. The first set of image objects is arranged to result in at least a first synthetic guide image when placed near a focal length of the focusing elements and viewed through the focusing element array. The synthetic guide image, when moved for viewing in one of a set of separate directions, presents a first sub-image and a second sub-image, thereby moving them into a predetermined geometric relationship with respect to one another. The second set of image objects is arranged to result in at least a second synthetic effect image within a limited effect field of view of the synthetic effect image when placed near a focal length of the focusing elements and viewed through the focusing element array. The limited effect field of view of the synthetic effect image either includes viewing directions only in angular proximity to any of the directions of the set of separate directions, or excludes viewing directions only in angular proximity to any of the directions of the set of separate directions. Preferably, the first partial image and the second partial image are provided at different recognizable depths or heights.

The synthetic guidance image is thus used to find a particular viewing direction in which something surprising will occur. The synthetic guidance image can be designed in various ways. However, a common feature is that the synthetic guide image includes sub-images that behave in a way that intuitively tells the viewer how to tilt the synthetic image device.

If the partial images z. Eg provided at different height/depth, the normal way a three-dimensional object behaves allows a viewer to expect the sub-images to move in certain directions relative to each other when the synthetic guidance image is tilted.

The simplest example is a synthetic guidance image comprising two repeating two-dimensional patterns provided at different height/depth as indicated in Figures 8A & C. However, finding the viewing direction sought cannot be limited to aligned centers. FIG. 9A illustrates another example in which circles 71 in a top layer 48 form the first partial image 46. FIG. The circles 71 are intended to align with bridging objects 73 in a lower layer 49, thereby forming the second sub-image 47 as illustrated at the top of the figure.

Fig. 9B illustrates another embodiment in which the letters "O" 74 and "K" 75 at different heights/depths represent an upper layer 48 with a first partial image 46 and a lower layer 49 with a second partial image 47 to be provided. The required viewing direction is obtained when the phrase "OK" is formed as illustrated in the figure above.

The synthetic guide image 41 of the embodiments of Figures 9A-B is simply provided as a combination of two Moire-type synthetic images, but can also be achieved by a one-piece synthetic image.

Figure 9C illustrates yet another embodiment in which an obscuration sequence is used. A filled circle 77 is provided as a second sub-image 47 at a certain height/depth. Another unfilled circular area 76 is provided as a first partial image 46 at a different apparent height/depth above the apparent height/depth of the filled circles 77 . When the two partial images 46, 47 partially coincide, as illustrated in the upper part of the figure, the unfilled circular area 76 obscures parts of the filled circle 77 and the required viewing direction can be seen when total obscuration is achieved, i. i.e. when the filled circles 77 completely intersect with the unfilled circular area 76.

One skilled in the art will recognize that variations in the design of the synthetic guide image 41 are endless.

In the example presented above, the sub-images of the synthetic guide image were repeating patterns and also with an equal distance. Stated another way, in one embodiment, the synthetic guidance image comprises two pattern layers at different apparent heights and/or depths. The predetermined relative geometric relationship to each other corresponds to a predetermined intersection relationship.

This also means that there are other ways to combine the sub-images. Referring again to Figures 8A and B as an example, the crosses 72 may coincide with at least a plurality of the circles 71, thereby defining other viewing directions. The "effect" must then be performed in any of these directions. This is illustrated in FIG. Here two circles 71 are illustrated and two directions d connecting a center of a circle to the cross 72 are possible. These directions d thus together form a set D of individual directions in which alignment is achieved.

In another embodiment, an upper pattern layer of the two pattern layers has an apparent size that is close in size to an apparent depth of a lower pattern layer of the two pattern layers. This means that when the synthetic image device is tilted, the upper pattern layer appears to move a distance in one direction and the lower pattern layer moves an equal distance in an opposite direction. The apparent height spacing between the patterns thus becomes relatively large without having to use very high magnifications, which in turn means that the angular spacing between two adjacent directions of the set of separate directions where alignment occurs is easily designed can be made to be reasonably small. To move from a separate direction that overlaps with an adjacent one, each pattern layer need only move half the distance.

In a further embodiment, the upper pattern layer and the lower pattern layer have the same periodicity. In such an embodiment, the pattern coincidence occurs in the same direction over the entire surface of the synthetic image device, which typically simplifies design. A simple embodiment is illustrated in FIG. In this embodiment, the top layer 48 comprising the first sub-image 46 is provided at an apparent height +h above the surface 50 of the synthetic image device. The lower layer 49, which comprises the second sub-image 47, is at an apparent height - h, i.e. H. a depth of h, below the surface 50 of the synthetic image device.

In another embodiment, the top pattern layer and the bottom pattern layer have different periodicities as illustrated in Figures 12A-B. In this embodiment, the top layer 48 comprising the first sub-image 46 is provided at an apparent height h1 above a surface 50 of the synthetic image device. The bottom layer 49 comprising the second sub-image 47 is provided at an apparent height h2 above the surface 50 of the synthetic image device. In addition, the periodicity differs for the different layers. As seen in FIG. 12B , an occurrence of the repeating element of the first sub-image 46 can be simultaneously aligned 59 with an occurrence of the repeating element of the second sub-image 47 . Each appearance or disappearance of a synthetic effect image can occur in a portion P of the entire image area A, as will be discussed in more detail below.

In yet another embodiment, as illustrated in Figures 13A-B, a first image portion 46 in a top layer 48 can be combined with a printed second image portion 57 at or in the synthetic image device, e.g., in the image layer 10, work together. This printed second image portion 57 thus appears at a substantially zero height above the synthetic image device.

Also, more than two image parts may be used for alignment purposes of the present disclosure. Figure 14A illustrates an embodiment using three layers. Large circles are displayed in a first partial image 46 of a first slice. In a second partial image 47 of a second slice, smaller circles are displayed, three of which fit into one of the larger circles. In a partial image 43 of a third slice, even smaller circles are displayed, three of which fit into the circles of the second partial image 47 . The sub-images are provided at different heights and in certain well-defined directions, with the smaller circles fitting into each other, as illustrated in Figure 14B. As will be appreciated by those skilled in the art, any other types of images and any number of slices can be used for alignment or guidance purposes.

However, it is of course also possible to use non-repetitive synthetic guidance images. Such synthetic guidance images may advantageously be integral synthetic images.

As an example, the first and second sub-images 46, 47 may be parts of a common three-dimensional synthetic guidance image 41, as illustrated by an embodiment in Figure 15A. The synthetic guide image is in the form of a truncated pyramid 78 in this embodiment. In the left part of the figure the pyramid 78 can be seen from the side. A viewer can simply tilt the synthetic image device to achieve a perfect top view instead, as illustrated in the right part of the figure. The second sub-image 47 here consists of the lower edge of the truncated pyramid 78 and the first sub-image 46 consists of the upper edge of the truncated pyramid 78. If these two sub-images 46, 47 are centered in relation to each other, a plan view is obtained.

FIG. 15B illustrates a similar embodiment in which a support 79 is used as the synthetic guide image 41. FIG. In the left part of the figure the support 79 is viewed from the side, while in the right part of the figure the support is viewed from straight above the support 79 . The first partial image 46 consists of the upper edge of the support 79 and the second partial image 47 consists of the lower edge of the support 79.

The synthetic guidance image can also include various types of animation effects. In FIG. 16A , the synthetic image device 1 displays a synthetic guidance image 41 comprising a sphere 82 and a circle 81 . When tilting the synthetic image device 1 to place the ball 82 in the circle 81, the synthetic guide image 41 changes such that the circle 81 is reduced in size. This makes it appear as if the ball 82 is pressing on the circle 81 to shrink it. When circle 81 eventually disappears, the required viewing direction is achieved and a "surprise effect" may occur, as discussed in more detail below.

In Figure 16B, another embodiment using an animated synthetic guide image 41 is shown. Here, the synthetic guide image 41 is a pattern of circles including a first circle 83 and a second circle 84. When the synthetic image device 1 is tilted to the right, the circles 83, 84 expand until they touch. Then the required viewing direction is found. A "surprise effect", in this particular embodiment the appearance of the text "SURE", occurs.

In many applications, for the sake of clarity of the synthetic image, it is advantageous to remove at least some parts of the synthetic guide image when the required viewing direction is reached, or en route to that direction. To this end, in certain embodiments, at least part of the synthetic guidance image has a limited guidance field of view. This guidance field of view preferably excludes the directions in which the synthetic effect image is or is not present. The first partial image and/or the second partial image then disappears when the surprise effect occurs. To this end, the synthetic guidance image, when viewed in the particular direction, would present the first sub-image and the second sub-image in the predetermined relative geometric relationship with respect to each other if the limited guidance field of view were neglected.

In one embodiment, the guidance field of view is only valid for a portion of the synthetic guidance image.

In one embodiment, the part of the synthetic guidance image for which the guidance field of view is valid comprises the first field or the second field.

In some applications, as discussed below, it is not necessary for the synthetic guide image to disappear from the entire synthetic image device. This can e.g. B. be the case when the synthetic effect image appears only in a limited part of the device area. In such an embodiment, it is then useful to have the guidance field of view only apply to part of a total image area of the synthetic image device.

In certain embodiments, the guidance field of view is a two-dimensional field of view.

In other embodiments, the guidance field of view is a one-dimensional field of view.

So far, most of the description has focused on the behavior or design of the synthetic guidance image. In the following, the synthetic effect picture is the main goal. In general, it is possible to combine essentially any type of synthetic effect image approach with essentially any type of synthetic effect image approach.

The surprise effect created by the synthetic effect picture is mainly caused by the restriction of the field of view of the synthetic effect picture. In this regard, there are three main groups of synthetic effect pictures. One group includes synthetic effect images with a field of view restricted to a small angle about the direction selected by the synthetic guidance image. Another group includes synthetic effect images with a field of view restricted to all but a small angle about the direction selected by the synthetic guidance image. Finally, the last group includes synthetic effect images which are composed of synthetic effect images of the other two groups, thereby providing a change from one image to another upon entering the small angular range around the direction selected by the synthetic guidance image.

In certain embodiments, it is of interest that the overall image area of the synthetic image device represents the synthetic effect image. In other embodiments, however, it may instead be preferred to display the synthetic effect image only in selected parts of the overall image area (A) of the synthetic image device.

The synthetic effect image may also be configured to cooperate with the synthetic guide image to form a combined synthetic image within the effect field of view. Other examples are shown below.

One way of interacting with the synthetic guide image is to replace one of the sub-images of the synthetic guide image with the synthetic effect image within the effect field of view.

FIG. 17A illustrates an embodiment for a synthetic image device 1 . In this embodiment, the synthetic guidance image with circles and crosses (see Figures 8A&D) is used to define the required viewing direction. However, as discussed above, any type of synthetic guidance image approach can be used. In the left part of the figure, which represents a view outside the required viewing direction, only the synthetic guidance image 41 can be seen. When the required viewing direction is reached, illustrated in the right part of the figure, the synthetic guide image 41 disappears completely and is replaced by the synthetic effect image 42, which in this embodiment represents the words "PROTECTED". Here, the entire synthetic guidance image 41 has a limited guidance field of view that excludes the angles near the required viewing direction. The synthetic effect image 42 has an effect field of view that instead includes only the angles near the required viewing direction.

In Fig. 17B, another embodiment of a synthetic image device 1 is illustrated. The situation outside the required viewing direction is similar to Figure 17A, with only the synthetic guide image 41 being shown. When the required viewing direction is reached, illustrated in the right part of the figure, part of the synthetic guide image 41, the crosses, disappears and is replaced by the synthetic effect image 42, which in this embodiment has the word "OK" inside the circles of the synthetic Guide image 41 represents. Here, a portion of the synthetic guidance image 41 has a limited guidance field of view that excludes the angles near the required viewing direction. The other sub-image, the circles, do not have a limited field of view. Here too, the synthetic effect image 42 has an effect field of view which only includes the angles in the vicinity of the required viewing direction.

In Fig. 17C, another embodiment of a synthetic image device 1 is illustrated. The synthetic guide image 41 here comprises a pattern of circles and a pattern of filled squares, which consist of two sub-images. When the required viewing direction is reached, when the squares completely cover the circles, which is illustrated in the right part of the figure, an overlapping part of the filled squares and the circles of the synthetic guide image 41 disappears and is replaced by the synthetic effect image 42, which in this embodiment depicting the word "OK" within the circles of the synthetic guidance image 41 . Here, a portion of one of the sub-images of the synthetic guide image 41 has a limited guide field of view that excludes the angles near the required viewing direction. The other sub-image, the circles, do not have a limited field of view. Here too, the synthetic effect image 42 has an effect field of view which only includes the angles in the vicinity of the required viewing direction.

In Fig. 17D, another embodiment of a synthetic image device 1 is illustrated. The synthetic guidance image 41, similar to Figure 17A, is out of the required viewing direction. When the required viewing direction is reached, which is illustrated in the right part of the figure, the synthetic effect image appears, but only in a part P of the total image area A, whereby the synthetic guide image 41 is replaced. However, the synthetic guide image 41 is still present outside the part P of the overall image area A. Here, the synthetic guidance image 41 has a limited guidance field of view that excludes the angles near the required viewing direction, but only in region P. Also, within region P, the synthetic effect image 42 has an effect field of view that excludes only the angles near the required viewing direction required viewing direction.

It should be noted that the synthetic effect image can be of any type. Text is often self-explanatory, but other types of images, e.g. B. three-dimensional synthetic images can be used. At the end of the present disclosure, many different types of synthetic images are presented that can form the synthetic effect image and/or the synthetic guide image.

In one embodiment, a change in color can be used as a "surprise effect". If there is a synthetic guide image in one color used to determine the required viewing direction, a synthetic effect image in a different color with an effect field of view that includes only the angles near the required viewing direction will result in a striking effect. The synthetic effect image can be identical to the synthetic guide image except for color, or it can be a different image.

In Fig. 17E another embodiment of a synthetic image device 1 is illustrated. The synthetic guidance image 41 is similar to Figure 17D out of the required viewing direction. In this embodiment, the synthetic effect image 42, in this particular embodiment a pattern of rectangles, is present outside of the required viewing direction, as illustrated in the left-hand portion of the figure. However, when the required viewing direction is reached, illustrated in the right part of the figure, the synthetic effect image disappears. In this embodiment, the synthetic effect image 42 has an effect field of view that excludes the angles near the required viewing direction.

In Fig. 17F another embodiment of a synthetic image device 1 is illustrated. The synthetic guidance image 41 is similar to Figure 17D out of the required viewing direction. In this embodiment, the synthetic effect image 42, in this particular embodiment text "ALIGN CROSS AND CIRCLE", is present outside of the required viewing direction, as illustrated in the left part of the figure. However, when the required viewing direction is reached, illustrated in the right part of the figure, the synthetic guide image 41 disappears. In addition, the synthetic effect image 42 represents an inversion of the text "ALIGN CROSS AND CIRCLE" to a thumbs-up sketch. In this embodiment the entire synthetic guidance image 41 has a limited guidance field of view that excludes the angles near the required viewing direction. The synthetic effect image 42 consists of two parts, one corresponding to the thumbs-up character with an effect field of view including only the angles near the required viewing direction, and one corresponding to the text with an effect field of view including the angles near the required viewing direction viewing direction excludes.

In Fig. 17G another embodiment of a synthetic image device 1 is illustrated. The synthetic guidance image 41 is similar as before, with crosses 72 in an upper layer 48 to be aligned with circles 71 in a lower layer 49, as illustrated in the upper part of the figure. However, when the required viewing direction is reached, illustrated in the lower part of the figure, the top layer 48 of the synthetic guide image 41 disappears. Instead, the synthetic effect image 42 appears at an effect layer 44 with a recognizable position below the circles 71. The result for the View is thus that when the cross is aligned with the circles, the crosses "fall" through the circles and end up in another deeper layer. A change in depth is thus used as the "surprise effect". In this embodiment, the top layer 48 of the synthetic guide image 41 has a limited guide field of view that excludes the angles near the required viewing direction. The synthetic effect image 42, which is also a pattern of crosses, has an effect field of view that instead includes only the angles near the required viewing direction.

In Fig. 17H another embodiment of a synthetic image device 1 is illustrated. The synthetic guidance image 41 comprises a small solid square in an upper layer and a large empty square in a lower layer outside the required viewing direction. When the required viewing direction is reached, illustrated in the right part of the figure, the synthetic guidance image 41 is combined with the synthetic effect image 42 to present a three-dimensional image of a truncated pyramid. An abrupt change from two separate layers of two-dimensional figures to a full 3D image serves as the "surprise" effect. In this embodiment, the synthetic guidance image 41 does not have a limited guidance field of view, but it is always present. The synthetic effect image 42 has an effect field of view that includes only the angles near the required viewing direction.

The guidance and/or surprise effect can also take place in two or more steps. In Fig. 18 an embodiment is illustrated in which a synthetic guidance image 41 with circles and crosses is visible outside the required viewing direction. When the synthetic image device 1 is tilted so that the crosses come closer to the center of the circle, a new part of the synthetic guide image 41 is formed, in this embodiment a smaller circle. This smaller circle helps fine-tune the pitch. When the required viewing direction is reached, the crosses disappear and instead a synthetic effect image 42 appears, in this embodiment a pattern of stars.

In an alternative view, the small circles can be interpreted as a first part of a synthetic effect image. When the more precise viewing direction is reached, the synthetic effect image becomes a star.

As will be understood by those skilled in the art, the variations relating to the "surprise effect" can be designed using any synthetic image effects known in the art. These effects can only be provided by a separate synthetic effect image or by a combination between the synthetic effect image and changes in the synthetic guide image.

By using a combination of a synthetic guide image and a synthetic effect image, the use of a synthetic image device, e.g. as an authentication mark, easily, regardless of the relative orientation of the focusing elements and the image objects.

Illustrated in Figure 19 is a flow chart of steps of one embodiment of an authentication method. The method of authenticating an object with a synthetic image device provided on a surface of the object begins at step 200. At step 210, a first guide synthetic image of the synthetic image device is observed in a viewing direction. The synthetic guide image has a first sub-image and a second sub-image. In step 220, the synthetic image device is moved to change the viewing direction. This changing of the viewing direction causes the first partial image and the second partial image to move to a predetermined relative geometric relationship with respect to each other. In step 230, an abrupt change in the appearance of a second synthetic effect image is observed as an indication of authenticity when it is moved to the predetermined relative geometric relationship. The process ends in step 299.

The various embodiments of the synthetic image devices presented above can be manufactured by various methods that are well known in the art. A method of making a synthetic image device is set forth below, which method is particularly well suited to synthetic image devices of the type discussed above.

In a single-piece synthetic image approach, as mentioned above, non-identical fractional image objects are provided in cells associated with each focusing element.

Illustrated in Figure 20A is a series of cells C from various parts of one embodiment of a synthetic image device. The cells comprise a first set of image objects which result in a first synthetic guide image when placed in position in front of an array of focusing elements. A first type of image objects 17A results in an image of crosses, while a second type of image objects 17B results in an image of plus signs. As will be understood by those skilled in the art, image objects can be used for all of the various embodiments of synthetic guide images presented above and variations thereof.

The image of the crosses has a discernible height above the synthetic image device and the periodicity of the image objects 17A of the crosses is slightly greater than the periodicity of the cells C. Likewise, the image of the plus signs has a discernible depth below the synthetic image device Images on and the periodicity of the image objects 17B of the plus signs is slightly smaller than the periodicity of the cells C. The positions of the image objects 17A, 17B within the cells C therefore vary between different cells, as can be seen in the figure. In the second cell from the left in the figure, the image objects 17A, 17B overlap. This occurs at a particular first position 60. This means that the synthetic image device when viewed from a direction that brings the focusing element across the cell to select the first position 60 and an image with an intersecting cross and plus sign you can see. A similar situation occurs in the situation in the right part of the figure. However, the first position 60 is here close to a cell boundary. A total of four such first positions 60 can be seen in the present embodiment. If a viewing direction corresponding to any of these first sections 60 is selected, an image with an intersecting cross/plus sign will be seen. It should be noted that in the present embodiment there are more such first positions in each cell associated with overlapping situations in the cell above and below the illustrated cells, see Figure 20B.

In Fig. 20B, guidance view limiting regions 62 enclosing a first position 60 are illustrated, respectively. As can be seen in the second cell from the left, parts of the image objects 17A, 17B which should be present in the guidance view limitation area 62 are removed. This corresponds to the fact that the image disappears when viewed from the direction corresponding to the first position 60.

In Figure 20C, effect view limiting regions 63 enclosing a first position 60 are illustrated, respectively. In this embodiment, the effect view limitation areas 63 are the same as the guide view limitation areas 62. The image objects 17C belonging to a synthetic effect image are provided within the effect view limitation areas 63. FIG. In the present embodiment, the picture objects 17C belong to a synthetic effect picture in the form of a letter “A”. The parts of the image objects that fall outside the effect view limiting areas 63 are actually "removed" but are indicated by a dashed line in the figure for the purpose of explanation. This corresponds to the fact that the image of "A" suddenly disappears when viewed from one of the directions corresponding to the first position 60.

The full effect of the synthetic image device with the cells of Figure 20C is that the patterns of crosses and pluses are visible in different relationships to each other from most viewing directions. When the viewing direction gets close to the required one, the plus signs and crosses disappear and the letter “A” appears in their place.

In providing a method of manufacture, a similar approach outlined in Figures 20A-C can be used. Image objects of a synthetic guidance image can be represented by a numeric representation. Likewise, picture objects of a synthetic effect picture can also be represented by a numerical representation. By then defining an effect view bounding area that encloses the position in a cell in which the sub-images of the synthetic guide image achieve the required geometric relationship, the numerical representation of the image objects of the synthetic effect image can be modified to be visible either inside or outside the effect view bounding area . This modified representation of the image objects of the synthetic effect image can then be linked to the image objects of the synthetic guide image, which may also be modified with or without a guide view clipping area. This numerical representation of composite image objects can then be used to form an image layer by methods known per se.

FIG. 21A illustrates a cell C of a synthetic image device. In this embodiment, the guide vision limitation area 62 coincides with the effect vision limitation area 63 . The result is that the change in the synthetic guide image and the synthetic effect image occurs at the same viewing directions.

Fig. 21B illustrates a cell C of another synthetic image device. In this embodiment, there is no guidance view limitation area, and the synthetic guidance image can therefore be seen from all viewing directions. However, the effect view limitation area 63 still controls the appearance of the synthetic effect image.

Fig. 21C illustrates a cell C of another synthetic image device. In this embodiment, there are a guide view limitation area 62 and an effect view limitation area 63 . The result is that as the viewing direction gets closer to the required viewing direction, the synthetic guide image or at least part of it first disappears, and as the viewing direction changes further to the required viewing direction the synthetic effect image appears. In an alternative, the effect vision limitation area 63 encloses the guidance vision limitation area 62, which results in the synthetic effect image first appearing together with the synthetic guidance image, but as the viewing direction gets closer to the target, the synthetic guidance image, or at least part of it, disappears.

Fig. 21D illustrates a cell C of another synthetic image device. In this embodiment, the effect view limitation area 63 encloses the first position 60, but in an asymmetrical manner. This means that the appearance/disappearance of the synthetic effect image differs depending on the direction in which the viewing angle is changed.

In the previous embodiments, the effect view limitation area (63) and the guide view limitation area (62) were limited in two dimensions. Fig. 21E illustrates a cell C of another synthetic image device. In this embodiment, the effect vision limitation area 63 and the guidance vision limitation area 62 are instead limited in one dimension. This means that the first position 60 is included, but in an asymmetrical way. Here, the appearance/disappearance of the synthetic effect image and the disappearance of at least part of the synthetic guide image depends only on the viewing angle component in the vertical direction (as defined in the figure). In various alternatives, one of the effect vision limitation area 63 and the guidance vision limitation area 62 may be limited in two dimensions while the other is limited in one dimension.

In many of the embodiments illustrated above, the effect view limitation area 63 and the guide view limitation area 62 have the same symmetry as the C cell. However, this is not absolutely necessary. In FIG. 20C, circular effect view limiting areas 63 and guide view limiting areas 62 within a hexagonal cell C are illustrated. In Figure 21E, a rectangular effect view boundary area 63 within a hexagonal cell C is illustrated as another example of different symmetries.

In Fig. 21G, a cell C of another synthetic image apparatus is illustrated. In this embodiment, there are two guidance view limitation areas 62A,B. A full synthetic guidance image can be seen outside the first guidance view limitation area 62A. When the viewing direction corresponds to a point between the first guidance view boundary area 62A and the second guidance view boundary area 62B, a first change in the synthetic guidance image is seen. When the viewing direction corresponds to the first position 60, the synthetic effect image appeared along with a second variation of the synthetic guide image. This embodiment can be used to create the situation described in FIG. 18, for example.

This approach can be further developed to use animation features in the synthetic guidance image, see e.g. 16A-B. In Figure 21H, the synthetic guidance image is associated with five guidance view boundary regions 62A-E which result in a gradual change in the synthetic guidance image as the required viewing direction is approached.

In the above illustrated embodiments, hexagonal cells were used as examples. This can be a natural choice in many cases, particularly when using densely packed focusing element arrays. However, depending on the application, all types of cell geometries can be used. As non-limiting examples, Figure 21I illustrates a rhombic cell C and Figure 21J illustrates a rectangular cell C that can be used in conjunction with all of the different approaches presented above. In an embodiment in which the ratio between the periodicity of the image objects of one field of the synthetic guide image and the cell periodicity is equal to the ratio between the cell periodicity and the periodicity of image objects of another field of the synthetic guide image, the fields appear at a height and depth, each separated by an equal distance from the plane of the synthetic image device, e.g. 11. Stated another way, a ratio of a periodicity of a first subset of a first set of image objects and a focus assembly periodicity of the synthetic image device is equal to a ratio of the focus assembly periodicity and a periodicity of a second subset of the first set of image objects. When the synthetic image device is tilted, the different sub-images appear to move in opposite directions and again intersect when the point targeted by the focusing elements has moved half a cell distance. This results in having four first positions 60 in each cell and also four effect view limiting regions in each cell, as illustrated in Figure 22A.

However, in an approach similar to the one illustrated in Figures 13A-B, it is necessary for the cell's mapped point to move an entire cell distance before a next coincident synthetic guidance image can be reached. In such a system, there is only one first position 60 in each cell C, as illustrated in Figure 22B.

In addition, the coincidence of the sub-images of the synthetic guide image occurs in an approach similar to the one illustrated in Figures 12A-B at different viewing directions for different parts of the synthetic image device. Therefore, as illustrated in FIG. 22C, the effect view limiting regions 63 can also be positioned in different regions depending on where on the synthetic image device 1 the cell is located. This changing of position within the cell can be provided in a gradual manner on the surface or in steps, resulting in part-constant positions of the effect view limitation area 63 in different parts of the overall area of the synthetic image device 1 .

The present approach with a synthetic guide image and a synthetic effect image makes the alignment of the focusing elements and cells less sensitive. In Fig. 23A, a situation in which a cell C is perfectly aligned with a focusing element 24 is illustrated from above in the upper part of the figure and in a side cross-sectional view in the lower part of the figure. The first position 60 is designed to be positioned in the center of the cell C in this example. The synthetic effect image can be seen in such a situation when the synthetic image device is viewed from a perpendicular direction with respect to the main surface.

However, if the alignment is not perfect, as illustrated by Figure 23B, usability will not be significantly affected. Even if the cell C and the focussing element are displaced, there is a well-defined direction in which the first position 60 in the cell can be viewed through the focussing element 24 . Since the synthetic guide image tells the viewer how to achieve this viewing direction, the transition to the synthetic effect image is easy to find, regardless of the misalignment.

Referring to Figure 24, a flowchart illustrating steps of one embodiment of a method for fabricating a synthetic image device is shown. The process begins at step 300. At step 310, a numeric representation of a first set of image objects is created. The image objects are arranged in image cells to result in at least a first synthetic guide image when placed near a focal length of the focusing elements and viewed through a focusing element array. The synthetic guidance image represents a first partial image and a second partial image, with a relative geometric relationship to one another being changed when a viewing direction is changed. A predetermined relative geometric relationship between the first sub-image and the second sub-image corresponds to image objects positioned at a first position in each image cell. In step 320, an effect view limitation area is defined. The effect view boundary area includes the first position and a border. In step 320, a numeric representation of a second set of image objects is created. The second set of image objects is arranged to result in at least one second synthetic effect image when placed near a focal length of the focusing elements and viewed through the focusing element array. In step 340, the numerical representation of the second set of image objects is modified within or outside the effect view bounding area to result in an abrupt change in the appearance of the synthetic effect image. In step 350, the numeric representation of the first set of image objects and the numeric representation of the second set of image objects are combined into a numeric representation of composite image objects. In step 360, an image layer is formed according to the numerical representation of composite image objects. In step 370, a focusing element array is formed. The image layer is located near a focal length of the focusing elements of the focusing element array.

In one embodiment, the first sub-image and the second sub-image are presented at different apparent depths or heights.

In one embodiment, the method further comprises the further step 321, in which a guidance view limitation region comprising the first position and an edge is defined. In step 341, the numerical representation of the first set of image objects prior to the step 350 of connecting is modified within the guidance view bounding area.

In a further embodiment, the step 341 of modifying the numerical representation of the first set of image objects comprises modifying the numerical representation to correspond to removing parts of the first set of image objects.

In another embodiment, removing portions of the first set of image objects includes removing at least one of the first sub-image and the second sub-image.

In one embodiment, modifying 341 the numerical representation of the first set of image objects for cells is performed only within a portion of an overall image region of the synthetic image device.

In one embodiment, modifying 340 the numerical representation of the second set of image objects for cells is performed only within a portion of the total image area of the synthetic image device.

In one embodiment, the composite image objects within the effect view bounding area result in a combined three-dimensional synthetic image.

In one embodiment, the first set of image objects comprises two subsets of image objects, each corresponding to a pattern layer. The pattern layers have a different periodicity, with the predetermined relative geometric relationship corresponding to a predetermined overlapping relationship.

The manufacturing method thus yields a synthetic image device having an image layer formed according to a numerical representation of composite image objects and a focusing element array. The image layer is located near a focal length of the focusing elements of the focusing element array.

The numeric representation of the composite image objects is an amalgamation of a numeric representation of a first set of image objects and a numeric representation of a second set of image objects. The first set of image objects is arranged in image cells to result in at least a first synthetic guide image when placed near a focal length of the focusing elements and viewed through a focusing element array. The synthetic guidance image represents a first partial image and a second partial image, with a relative geometric relationship to one another being changed when a viewing direction is changed. A predetermined relative geometric relationship between the first sub-image and the second sub-image corresponds to image objects positioned at a first position in each image cell. An effect view bounding area includes the first position and a border.

The second set of image objects is arranged to result in at least one second synthetic effect image when placed near a focal length of the focusing elements and viewed through the focusing element array. The numerical representation of the second set of image objects is modified within or outside the effect view bounding area to result in an abrupt change in the appearance of the synthetic effect image before the merging occurs.

As previously mentioned, animation techniques may be advantageously used in conjunction with the synthetic guide image and/or the synthetic effect image. Various animation aspects that can be used in connection with the synthetic guide image and/or the synthetic effect image are discussed below. However, it is also possible to use these animation aspects in other types of applications that do not involve interaction between synthetic guide and effect images.

[0128] Using various types of integral image techniques, there is no limit to repeated patterns or two-dimensional images. In addition, it is also possible to change the appearance of the synthetic image for different viewing directions. This allows different types of animation or morph effects to be displayed. A limitation of the prior art integral image techniques is that the animations and morph techniques are confined to a single cell. As the viewing direction changes, the point in the cell from which the visual information is collected also changes. When this point reaches the cell boundary and continues into a neighboring cell, the typical result is a sudden reversal of the synthetic image into the synthetic image of the neighboring cell.

However, there are arrangements that at least partially remove such unwanted reversals.

Cells used to define the integral synthetic image are typically equidistant as the array of focusing elements with which they are intended to interact. However, the shape and relative positioning may differ. 25A schematically illustrates an embodiment of the relationship between an arrangement of focusing elements 24 and an arrangement of cells C for the image object. In this embodiment, the focusing elements 24 are spherical lenses. Cells C were given a rectangular shape instead. The image objects present within cell C are associated with one or more focusing elements 24 and are intended to be viewed primarily through that focusing element. However, if there is significant misalignment, or if the synthetic image device is viewed at a relatively low angle, the image objects can also be viewed through an adjacent focusing element. Changing the point of view between two adjacent cells often results in a sudden reversal of the synthetic image.

In Fig. 25B, another embodiment of the relationship between an arrangement of focusing elements 24 and an arrangement of cells C for the image object is illustrated. In this embodiment, the cells are rectangular and an aspect ratio of the cells C is larger than in a previous embodiment, with a larger elongation in the lateral direction as illustrated. This results in the cells comprising points that may be physically located under an adjacent focusing element instead of the associated one. Likewise, there are points that are physically below the associated focusing element and instead belong to a neighboring cell. With such an approach, the viewing angle reversals of the synthetic image occur less frequently when the synthetic image device is tilted sideways than when the synthetic image device is tilted up and down.

Figure 25C illustrates an embodiment of the relationship between an array of focusing elements 24 and an array of cells C for the image object, the cells having a regular hexagonal shape. In this embodiment, however, there is a misalignment between the focusing element array and the cells C. This means that the image objects that are in the center of the cell are viewed by a viewer at a non-perpendicular angle with respect to the main surface of the device for synthetic pictures can be seen.

In Figure 26, a series of cells C of one embodiment of a synthetic image device is illustrated. The area of the cell is divided into five channels 80A-80E in this embodiment. Image objects corresponding to a particular integral synthetic image are provided in each channel. In other words, a channel is a portion of a cell that includes image objects that are used to create a same synthetic image. The integral synthetic images associated with the various channels 80A-80E differ. The differences can be large and in such cases sudden, abrupt changes in the synthetic image being viewed will be perceived by a viewer as the synthetic image device is tilted. Alternatively, the differences may be small, at least relative to the adjacent channels. This allows for synthetic images that morph when the synthetic image device is tilted, or other types of animation effects.

In figure 26 three examples of synthetic images generated by image objects of the different channels are illustrated. The image objects within channel 80A result in a pattern of star-like objects 81A. The image objects within channel 80C result in a pattern of squares 81B. The image objects within channel 80E result in a pattern of circles 81C. When tilting the synthetic image device, a gradual change from the star-like objects 81A to the circles 81C is perceived by a viewer. In addition, if the point from which the focusing element collects its information crosses the cell boundary and enters a neighboring cell, the same image objects are also displayed there, which means that there is no inversion of the synthetic image.

It can be difficult to design image objects that yield such seamless synthetic images in all directions, since there can be many relationships within the image that must be satisfied. However, since the natural way of tilting a synthetic image device is either sideways or up and down and not in any intermediate direction, it is often sufficient to cause the synthetic image to behave consistently in only one direction.

In Figure 27A a pair of cells C of another embodiment are illustrated schematically. In this embodiment, the cell is divided into parallel striped channels 80A-80I. Each channel 80A-80I comprises image objects which in cooperation with image objects of other cells when viewed through an array of focusing elements result in a synthetic image. The synthetic image associated with a channel differs from the synthetic image associated with an adjacent channel in the same cell C. The associated synthetic images of the present embodiment are schematically illustrated in a row below the cells.

It is assumed that the synthetic image device 1 with the cells is viewed from a direction from which the focusing elements select a point 84 in each cell C from which image information is collected. Together, the image objects at these points 84 result in a synthetic image showing a square 82A. This is illustrated in the lower left portion of Figure 27B. When the synthetic image device 1 is tilted laterally to the right, the point from which the focusing element collects information moves to the right, as illustrated by arrow 83A in Fig. 27A. The resulting synthetic image at the synthetic image device 1 shows a square with a rounded end 82B. This is illustrated in the lower middle portion of Figure 27B. Further tilting of the synthetic image device 1 moves the point according to the arrow 83B in Fig. 27A and a circle 82C appears as the synthetic image. This is illustrated in the lower right portion of Figure 27B. During side-tilting, the synthetic image represents a gradual change or morphing of the image. Even though side-tilting takes point 84 out of the intended cell and into an adjacent cell on the side, the seamless morphing is still present.

However, when the synthetic image device 1 is tilted upwards from the situation where a square 82A is shown, the point 84 also moves upwards according to the arrow 83C and therefore intrudes into an adjacent cell above the original one cell one. This results in an abrupt inversion of the square 82A into a circle 82C as illustrated in the upper left portion of Figure 27B.

As will be understood by those skilled in the art, the synthetic image device 1 can be rotated in any direction, e.g. For example, the morph direction corresponds to a tilt up and down, while the reverse direction is to the side.

Figures 27C and 27D illustrate another similar embodiment in which the synthetic images are three-dimensional solids. A cube 82D turns into a sphere 82F via a partially rounded cube 82E in a morphing manner when the synthetic image device 1 is tilted sideways. However, when the synthetic image device 1 is tilted upward, a sudden reversal occurs from the cube 82D to the sphere 82F.

When using three-dimensional synthetic images, it is particularly advantageous to have the morph direction as a sideways tilt. Since the three-dimensional perception is caused by the distance between the viewer's eyes, gradually changing the synthetic image in the same direction, i. H. the direction between the eyes, the perception of a realistic three-dimensional impression, even during a morph process.

As an example, a synthetic image apparatus includes an image layer having image objects provided in a plurality of cells and a focusing element array having a plurality of focusing elements. Each cell is associated with a respective focusing element. The image layer is located near a focal length of the focusing elements.

Each cell is divided into a plurality of striped channels. The image objects from each channel, together with image objects of the corresponding channel from other cells, when viewed through the focusing element array, form a synthetic image. The synthetic image associated with a channel differs from the synthetic image associated with an adjacent channel in the same cell C. Preferably, the striped channels are straight and parallel.

Preferably, the synthetic image associated with the channel closest to one end of the cell in one direction on the striped channels is the same or at least almost the same as the synthetic image associated with the channel closest to the opposite end of the cell is associated. This results in an inversion-free transition across the cell boundary.

The possible variations of objects are endless. Figure 28 schematically illustrates a series of arrows associated with stripe-like channels, analogous to the previous figures. In one viewing direction, an arrow pointing to the right 82G can be seen. By tilting the synthetic image device 1 sideways, the arrow rotates e.g. to the position pointing up 82H and also fully to the left arrow 82I. A tilt in the vertical direction instead gives a reversal directly to the left arrow 821.

There are many ways to use morphing to create a striking effect. In Fig. 29A, a series of synthetic images of a synthetic image device 1 is illustrated. Typically, the different images are achieved by tilting the synthetic image device 1 in one direction at the strip-shaped channels, as discussed above. In a first direction, no synthetic image is visible at all. By tilting the synthetic image device 1 slightly, a pattern of dots appears. With further tilting, the dots evolve into small stars, which grow with further tilting until the tips meet. A pattern of lines creating triangles in two directions is thereby created.

In an alternative embodiment, the images in Figure 29A may have elements at different apparent height/depth. For example, every other star could be provided at a different altitude than the others. This then leads to a relative shift in pitching between the different heights.

Yet another similar embodiment is illustrated in Figure 29B. Here are provided two sets of synthetic images that morph in opposite directions. If one set starts at an empty pattern, via dots and dots to a line pattern, the other set instead starts from the line pattern, via stars and dots to an empty pattern.

Figure 30 illustrates an embodiment of an animation using a combination of two interacting patterns. A pattern of circles 85 appears first. The circles enlarge and morph into windows 86. Seen through windows 86 is a pattern of letters "A" 87 at an apparent depth below the surface. The windows 86 continue to enlarge and eventually the pattern of "A" 87 covers the entire image.

This scenario is also achieved by using different channels within the cells. Strip-shaped channels are preferably used. In each channel, image objects contribute to the construction of the combination of images. To this end, image objects associated with the pattern of "A" are removed anywhere outside of the image objects associated with the window. It should be noted that, in different embodiments, the image appearing in the windows can be of any type; two-dimensional or three-dimensional, Moire-type or one-piece synthetic image. Of course, the shape of the "opening windows" can also differ in alternative embodiments.

It should be noted that striped channels can be used with any type of cell shape. However, it is preferred if the strip-shaped channels are positioned substantially parallel to one of the main cell boundary portions.

Figure 31A illustrates a schematic illustration of a synthetic image device 1 which is a combination of a two-dimensional and three-dimensional synthetic image. A pattern of two-dimensional hexagons 88 covers most of the surface. One of the hexagons, e.g. B. the one which on each occurrence appears to be directly in front of the viewer's eyes is replaced or its formation completed from a hexagonally shaped cup 89 with a noticeable extension below the surface. The three-dimensional hexagonally shaped cup 89 has a limited field of view, which is determined by the hexagon 88 associated therewith. The top of the three dimensional hexagonal shaped cup 89 coincides with the two dimensional hexagons 88 laterally as well as at apparent height/depth.

When the synthetic image device 1 is tilted, the cup closes and instead another hexagon opens to form another cup, such as in Figure 31B.

In another embodiment, this can be further combined with yet another synthetic image, as illustrated in Figure 31C. The synthetic image in the shape of a hand 90 has a discernible height above the surface. By tilting the synthetic image device 1 so that the hand 90 comes over a particular hexagon, the hexagon opens and reveals the cup underneath. At the same time, the hand disappears. The effect then looks like the hand removing a cap over each hex. The hexagon pattern 88 and the hand 90 are seen as a composite synthetic guide image and the three dimensional hexagonal shaped cup 89 then forms a synthetic effect image.

The embodiments described above are to be construed as a few illustrative examples of the present invention. It should be understood by those skilled in the art that various modifications, combinations and alterations can be made in the embodiments without departing from the scope of the present invention. In particular, in the various embodiments, different partial solutions can be combined in other designs if this is technically possible. The scope of the present invention is defined by the appended claims.

Claims (31)

1. Apparatus (1) for synthetic images; full an image layer (10); and a focusing element assembly (20); the image layer (10) being located in a vicinity of the focusing distance of the focusing elements (22) of the focusing element array (20); wherein composite image objects (36) of the image layer (10) is a merging, within cells (16) of the image layer, of at least a first set (31) of image objects (12) and a second set (32) of image objects (12); the cells (16) of the image layer (10) each being associated exclusively with a focusing element (22); the first set (31) of image objects (12) being arranged to result in at least a first synthetic guide image (41) when viewed through the focusing element array (20); wherein the synthetic guide image (41), when moved for viewing in one direction (d) from a set (D) of separate directions, comprises a first sub-image (46) and a second sub-image (47), whereby the first sub-image ( 46) and the second partial image (47) are moved to a predetermined geometrical relationship with respect to each other; the second set (32) of image objects (12) being arranged to result in at least a second synthetic effect image (42) within a limited effect field of view (52) of the synthetic effect image (42) when viewed through the focusing element array (20) is looked at; wherein the limited effect field of view (52) of the synthetic effect image (42) is selected from one of: including a viewing direction only in direction (d) of the set (D) of separate directions; and excluding a viewing direction only in direction (d) of the set (D) of separate directions. 2. Synthetic image device according to claim 1, characterized in that the first set of image objects of the image layer provided in the vicinity of the focusing distance of the focusing elements (22) is arranged to give the first partial image (46) and the second partial image (47), so that the first partial image (46) and displaying the second partial image (47) at a different apparent depth or height with respect to the synthetic image device. 3. Apparatus for synthetic images according to claim 1 or 2, characterized in that the synthetic guide image (41) when viewed in the direction (d) of the set (D) of separate directions comprises the first sub-image (46) and the second sub-image (47) in the predetermined relative geometric direction with respect to each other, and the limited effect field of view (52) of the synthetic effect image (42) excludes the viewing direction only in direction (d) of the set (D) of separate directions. Synthetic image device according to claim 1 or 2, characterized in that the synthetic guide image (41) has a limited guide field of view (51) excluding the direction (d) of the set (D) of separate directions. Synthetic image device according to Claim 4, characterized in that the guide field of view (51) is only valid for part of the synthetic guide image (41). Synthetic image device according to Claim 5, characterized in that a part of the synthetic guide image (41) for which the guide field of view (51) is valid comprises the first partial image (46). Synthetic image device according to any one of claims 4 to 6, characterized in that within the limited effect field of view (52) in a part (P1) the synthetic effect image (42) replaces the synthetic guide image (41). Synthetic image device according to any one of Claims 4 to 7, characterized in that the guide field of view (51) has boundaries in two dimensions. Synthetic image device according to any one of Claims 4 to 7, characterized in that the guide field of view (51) has boundaries of only one dimension. Synthetic image device according to any one of claims 4 to 9, characterized in that the synthetic guide image (41) when viewed in the direction (d) of the set (D) of separate directions comprises the first partial image (46) and would display the second partial image (47) in the predetermined relative geometric relationship with respect to each other if the limited guidance field of view (51) were neglected. Synthetic image device according to any one of Claims 1 to 10, characterized in that the synthetic effect image (42) is only visible in a limited part of the image layer (10). Synthetic image apparatus according to any one of claims 1 to 11, characterized in that the synthetic guide image (41) and the synthetic effect image (42) cooperate to form a combined synthetic image (45) within the effect field of view (52). Synthetic image apparatus according to any one of claims 1 to 12, characterized in that the first set of image objects of the image layer provided in the vicinity of the focusing distance of the focusing elements (22) is arranged around the synthetic guide image (41). result, the synthetic guidance image (41) comprising a first pattern layer (48) and a second pattern layer (49), the first sub-image (46) being comprised in the first pattern layer (48) and the second sub-image (47) being comprised in the second pattern layer (49), wherein the first pattern layer (48) and the second pattern layer (49) are located at different discernible heights and/or depths, and wherein the predetermined relative geometric relationship of the first partial image (46) and the second partial image ( 47) to each other corresponds to a predetermined overlapping relationship. Synthetic image apparatus according to claim 13, characterized in that the first set of image objects of the image layer provided in the vicinity of the focusing distance of the focusing elements (22) are arranged to give the synthetic guide image (41) such that the first pattern layer (48) is provided at an apparent height +h above the synthetic image device (1), and the second pattern layer (49) is provided at an apparent depth -h below the synthetic image device (1). The synthetic image device according to claim 14, characterized in that the first pattern layer and the second pattern layer have the same periodicity. The synthetic image device according to claim 14, characterized in that the first pattern layer and the second pattern layer have different periodicities. Synthetic image device according to any one of claims 1 to 16, characterized in that the synthetic effect image (42) replaces the first partial image (46) of the synthetic guide image (41) within the effect field of view (52). 18. A method of making a synthetic image device, comprising the steps of: - generating (310) a numerical representation of a first set of image objects (17A, 17B) arranged in image cells (C) to result in at least one, first, synthetic guide image (41) when it comes to a proximity of the focusing distance the focusing elements (22) are placed and viewed through a focusing element array (20); each image cell (C) being associated exclusively with one focusing element (22); wherein the synthetic guide image (41) representing a first sub-image (46) and a second sub-image (47) changes a relative geometric relationship to each other when changing a viewing direction; a predetermined relative geometric relationship between the first sub-image (46) and the second sub-image (47) corresponding to image objects (12) positioned at a first position (60) in each image cell (C); - defining (320) an effect view limitation region (63) comprising the first position (60) and an edge; - generating (330) a numerical representation of a second set of image objects (17C) arranged to result in at least one second synthetic effect image (42) when placed in a vicinity of the focusing distance of the focusing elements (22) and viewed through the focusing element assembly (20); - modifying (340) the numerical representation of the second set of image objects (17C) inside or outside the effect view bounding area (63) to result in an abrupt change in the appearance of the synthetic effect image (42); - combining (350) the numeric representation of the first set of image objects (17A, 17B) and the numeric representation of the second set of image objects (17C) in the image cells into a numeric representation of composite image objects (30); - forming (360) an image layer (10) according to the numerical representation of composite image objects (30); and - forming (370) a focusing element array (20); wherein the image layer (10) is located in a vicinity of the focusing distance of the focusing elements (22) of the focusing element array (20). The method of claim 18, characterized in that the step of generating the numerical representation of the first set of image objects of the image layer to be located near the focusing distance of the focusing elements (22) around the first sub-image (46) and the second sub-image (47) comprises arranging the first set of image objects of the image layer such that the first sub-image (46) and the second sub-image (47) are presented at different apparent depths or heights. A method according to claim 18 or 19, characterized by the further step of: - defining (321) a guidance view constraint area (62) comprising the first position (60) and an edge; - modifying (341) the numerical representation of the first set of image objects (17A, 17B) within the guidance view bounding area (62) prior to the step of connecting (350). The method of claim 20, characterized in that the step of modifying (341) the numerical representation of the first set of image objects (17A, 17B) comprises modifying the numerical representation to allow for removing parts from the first set of image objects (7A, 17B). A method according to claim 21, characterized in that removing parts from the first set of image objects (7A, 17B) comprises removing the first partial image (46). A method according to claim 21 or 22, characterized in that removing parts from the first set of image objects (7A, 17B) comprises removing the second partial image (47). A method according to any one of claims 20 to 23, characterized in that modifying (341) the numerical representation of the first set of image objects (7A, 17B) is performed for cells in only a part (P) of the image layer (10). A method according to any one of claims 18 to 24, characterized in that modifying (340) the numerical representation of the second set of image objects (17C) is performed for cells in only a part (P) of the image layer (10). A method according to any one of claims 18 to 25, characterized in that the composite image objects (30) within the effect view limitation area (63) result in a combined three-dimensional synthetic image. A method according to any one of claims 18 to 26, characterized in that the first set of image objects (17A, 17B) comprises two subsets of image objects, each corresponding to a pattern layer, the pattern layers having a different periodicity, the predetermined relative geometric relationship corresponds to a predetermined intersection relationship. A method according to claim 27, characterized in that a ratio of a periodicity of the first subset and a periodicity of the focusing assembly of the synthetic image device (10) is equal to a ratio of the periodicity of the focusing assembly and a periodicity of the second subset. A method according to any one of claims 18 to 28, characterized in that at least one of the effect vision limitation area (63) and the guidance vision limitation area (62) is limited in two dimensions. A method according to any one of claims 18 to 28, characterized in that at least one of the effect vision limitation area (63) and the guide vision limitation area (62) is limited in one dimension. 31. A method of authenticating an object with a synthetic image device provided on a surface of the object, the method comprising: - observing a first synthetic guide image (41) of the synthetic image device in a viewing direction, the synthetic guide image (41) having a first sub-image (46) and a second sub-image (47) of different apparent depth or height; - moving the synthetic image device to change the viewing direction to cause the first sub-image (46) and the second sub-image to move to a predetermined relative geometric relationship with respect to each other; - observing an abrupt change in appearance of a second synthetic effect image (42) when moved to the predetermined relative geometric relationship as a sign of authenticity.